CN210124365U

CN210124365U - Gear-constrained helmet with variable jaw protection structure

Info

Publication number: CN210124365U
Application number: CN201920274880.XU
Authority: CN
Inventors: 廖浩甜
Original assignee: JIANGMEN PENGCHENG HELMETS Ltd
Current assignee: JIANGMEN PENGCHENG HELMETS Ltd
Priority date: 2019-03-04
Filing date: 2019-03-04
Publication date: 2020-03-06
Anticipated expiration: 2029-03-04

Abstract

The utility model relates to a variably protect jaw structure helmet, it includes the helmet shell main part, protect the jaw and protect the fork on the jaw, adopt the collet, the fork is, the internal gear, the external gear, the associative mechanism is constituteed to the driving medium, wherein the dead axle is all made to internal gear and external gear and the meshing restraint is vice, the internal gear is vice with the fork slip fit each other and form the slip restraint, the driving medium transmits the motion of external gear for the fork and impels to protect the jaw to produce the flexible displacement of relative helmet shell main part, thereby reach and protect jaw and still compound the action of coming and going when turning motion, thereby realize protecting the jaw position appearance conversion between full helmet position and half helmet position. The fork handle can cover the through groove on the inner gear in the jaw protection overturning process, so that external foreign matters are prevented from entering the gear pair, the use reliability of the helmet is ensured, external noise can be blocked from invading the helmet, the use comfort of the helmet is improved, the occupied space of the gear rotating in a fixed shaft is small, conditions are created for improving the rigidity of related parts, and the use safety of the helmet is also improved.

Description

Gear-constrained helmet with variable jaw protection structure

Technical Field

The utility model belongs to the technical field of human safety protection utensil, it relates to a helmet for protecting human head safety, and specifically speaking relates to a helmet that possess jaw protection formula protective structure, and more specifically says and relates to a helmet that can make jaw protection position and gesture can change between full helmet structure and half helmet structure as required.

Background

It is well known that users of various motor vehicles, racing cars, racing boats, balance cars, aircraft, and even cycling bikes, during their manoeuvre of the implement, should wear a helmet to protect their head; in addition, in many special work situations, such as those working in painting shops, fire fighting, anti-terrorism and anti-riot and in harsh environments such as mining, coal mining, tunneling, etc., they also need to wear helmets to protect their heads from various injuries from casualties. Currently, the structural types of helmets mainly include full-helmet type helmets, which are provided with a jaw guard for surrounding the chin of a user, and half-helmet type helmets, which do not have such a jaw guard. As for the helmet with the full-helmet structure, the helmet with the jaw protection structure can play a better role in protecting the head of a wearer; for the helmet with the half-helmet structure, better humanization is realized because organs such as the mouth, the nose and the like of a wearer are not tied by a jaw guard.

The jaw and shell of the traditional helmet are integrated, i.e. the jaw is relatively fixed relative to the shell. Undoubtedly, the conventional helmet of one-piece construction is sturdy and secure, and therefore it has sufficient safety protection for the wearer. However, considering from another aspect, there are also drawbacks to the full helmet of one-piece construction: firstly, from the use point of view, when a wearer needs to take activities such as drinking, talking, resting and the like, the wearer needs to take off the helmet first to complete corresponding actions, and undoubtedly, the performance of the traditional integral structure type full-helmet is dull and inconvenient; secondly, from the production perspective, the helmet with the integrated structure has the structural characteristic that the large inner cavity is matched with the small opening, so that the mold is very complicated, the production efficiency is not high, and the reason that the manufacturing cost of the helmet with the integrated structure is high is solved.

Obviously, the traditional helmet with an integrated full helmet structure cannot meet the requirements of multiple targets such as safety, convenience, low cost and the like. In view of this, it is a natural object of the present helmet researchers and manufacturers to develop a helmet that combines the advantages of safety of the full helmet structure and convenience of the half helmet structure. Against this background, the applicant of the present patent proposed "a helmet with a variable jaw structure based on gear constraint" in chinese patent application CN105901820A, the greatest feature of the invention is that: the helmet shell is characterized in that two cylindrical gear type fixed inner gears are respectively arranged beside two sides of the helmet shell, two cylindrical gear type rotating outer gears are correspondingly and fixedly arranged on two fork handles of the jaw guard, corresponding arc-shaped restriction grooves are formed in a bottom support fixedly connected with the helmet shell, the rotating outer gears and the fixed inner gears are limited by the restriction grooves to be meshed and form a kinematic pair, so that the position and the posture of the jaw guard are restricted according to the requirement of a preset process, the jaw guard finally runs according to a planned track between the full helmet structure position and the half helmet structure position and can be reversely converted mutually, in other words, the jaw guard can be lifted from the full helmet structure position to the half helmet structure position as required, and vice versa. Meanwhile, the jaw guard and the helmet shell main body are not integrated into a whole, so that a mold for manufacturing the helmet is simpler, the manufacturing cost can be reduced, and the production efficiency can be improved. Obviously, the gear-constrained variable jaw-protecting structural scheme provided by the patent application can better meet the multi-objective requirements of safety, convenience and low cost, thereby promoting the progress of helmet technology.

However, although the helmet with variable jaw structure proposed in chinese patent application CN105901820A has self-evident advantages, it has several disadvantages, which are: 1) the longer and arc-shaped restraining slot creates a safety hazard in the reliability of the helmet, since when the chin bar is in its position, especially when the jaw guard is in a certain intermediate position state of the full helmet structure and the half helmet structure to form a so-called uncovering helmet (the helmet belongs to a form of a 'quasi-half helmet structure helmet', the state is favorable for the wearer to drink water, talk, temporarily ventilate and the like, and is particularly suitable for gallery operation), because the jaw guard can not completely cover the restraint slot, namely, the handle body of the jaw guard can not effectively cover the through long arc restraint slot, and as a result, an opportunity is created for external foreign matters to enter a meshing kinematic pair formed by the rotating external gear and the fixed internal gear, once the occasion is generated, the gear restraint pair is easy to be stuck, in other words, the reliability of the helmet has certain hidden danger in the using process; 2) the existence of the arc-shaped restraining grooves with long length also causes the noise of the helmet to be larger, and also when the jaw guard is required to be in a certain intermediate position state of the full helmet structure and the half helmet structure in the process of changing the position of the jaw guard, so as to form a so-called uncovering helmet, the jaw guard can not completely cover the restraining grooves for a rider, so that the whistle sound energy generated by the external air flow flowing through the outer surface of the helmet is easily transmitted into the interior of the helmet from the through restraining grooves, and the restraining grooves are just arranged near the two ears of the wearer, so that the sound insulation effect of the helmet is poor or the comfort is poor; 3) the layout and operation of the external planetary gear can weaken the safety of the helmet to a certain extent, because the jaw guard can change the structure position, because the external gear moves along with the jaw guard to present the planetary rotation behavior, it can be easily found that the swept space area is larger, and it is obviously impossible to arrange a fastening screw or other fastening structure in the range of the space area passed by the external gear, at this time, the bottom base with the long arc type restriction slot will be forced to be arranged into a thin shell-shaped component with larger span, it is known that the component with such structure has smaller intrinsic rigidity, that is, the rigidity of the helmet shell is weaker, in other words, the safety of the helmet is weakened.

In summary, although the gear-constrained variable jaw guard structure type helmet can realize the switching of the jaw guard between the full helmet position and the half helmet position, the gear-constrained variable jaw guard structure type helmet has the defects of poor reliability, comfort and safety. In view of the above, there is still room for further improvement and improvement in the existing helmet with a variable jaw protection structure.

Disclosure of Invention

To the above-mentioned problem that current gear constraint variable jaw structure type helmet exists, the utility model provides a gear constraint variable jaw structure helmet that protects, aim at: compared with the existing gear constraint variable jaw protection structure technology, the gear constraint variable jaw protection structure has the advantages that the structure layout and the driving mode of the gear constraint mechanism are improved, the jaw protection structure can accurately convert the position and the posture between a full helmet structure and a half helmet structure, and meanwhile, the reliability, the comfort and the safety of a helmet can be further effectively improved.

The purpose of the utility model is realized like this: a gear-constrained helmet with a variable jaw protection structure comprises a helmet shell main body, a jaw protection and two bottom supports, wherein the two bottom supports are respectively arranged on two side surfaces of the helmet shell main body and are fastened on the helmet shell main body or are manufactured with the helmet shell main body in an integrated structure; the method is characterized in that: the helmet shell comprises a helmet shell body, a base, a pair of inner gears and an outer gear, wherein the helmet shell body is provided with a helmet shell body, the helmet shell body is provided with a pair of through holes, the inner gears are correspondingly provided with inner gears and outer gears, the inner gears are restrained by the base or/and the helmet shell body, the outer gears are restrained by the base or/and the helmet shell body, the inner gears rotate around the axes of the inner gears and the outer gears rotate around the axes of the outer gears, a through groove is formed in the body of the inner gears or an attachment piece of the inner gears, a transmission piece penetrating through the through grooves is additionally arranged, and the base; in the same associated mechanism, the fork handle is arranged outside the through groove on the inner gear, the outer gear and the inner gear are meshed with each other and form a motion constraint pair, the inner gear and the fork handle are mutually matched in a sliding manner and form a sliding constraint pair, one end of the transmission piece has a matching constraint relation with the outer gear, the transmission piece can receive the drive of the outer gear or the outer gear can receive the drive of the transmission piece through the constraint relation, and the other end of the transmission piece has a matching constraint relation with the fork handle and enables the fork handle to receive the drive of the transmission piece or the transmission piece can receive the drive of the fork handle through the constraint relation; the four parts execute the driving and operating logic at least comprising one of the following situations a), b) and c):

a) firstly, the jaw protector makes an original turning action, then the jaw protector drives the internal gear to generate a rotating motion through the fork handle, then the internal gear drives the external gear to generate a rotation through a meshing relation, then the external gear drives the fork handle to generate an action through the transmission part and enables the fork handle to generate a sliding displacement relative to the internal gear under the combined constraint of the sliding constraint pair, and finally the jaw protector correspondingly changes the position and the posture along with the turning process;

b) firstly, the internal gear makes primary rotation action, then the internal gear drives the jaw guard to generate corresponding turnover motion through a sliding constraint pair consisting of the internal gear and the fork handle, meanwhile, the internal gear drives the external gear to rotate through a meshing relation, further the external gear drives the fork handle to generate action through a transmission piece, the fork handle generates sliding displacement relative to the internal gear under the combined constraint of the sliding constraint pair, and finally the jaw guard correspondingly changes the position and the posture along with the turnover process;

c) firstly, the external gear makes primary rotation action, then the external gear drives the internal gear to rotate through meshing relation, then on one hand, the internal gear drives the jaw guard to generate corresponding turnover motion through a sliding constraint pair consisting of the internal gear and the fork handle, on the other hand, the external gear drives the fork handle to generate action through a transmission piece, and under the combined constraint of the sliding constraint pair, the fork handle generates sliding displacement relative to the internal gear, and finally, the jaw guard changes the position and the posture of the jaw guard correspondingly along with the turnover process of the jaw guard.

Further, the motion constraint pair formed by the inner gear and the outer gear in the same associated mechanism belongs to the category of a plane gear transmission mechanism.

Further, the internal gear and the external gear in the same related mechanism are of a spur gear type, and an internal gear pitch circle radius R formed on the internal gear and an external gear pitch circle radius R formed on the external gear satisfy a relation R/R of 2 when they are meshed with each other.

Further, the transmission member in the same related mechanism includes a surface of revolution structure including a revolution axis which always synchronously follows the external gear to make a fixed axis rotation around the axis of the external gear, the revolution axis being arranged in parallel with the axis of the external gear and intersecting the pitch circle of the external gear.

Furthermore, the revolution surface of the transmission member is in a cylindrical surface structure or a conical surface structure.

Further, the matching and restricting relationship between the transmission piece and the external gear is that the transmission piece and the external gear are connected in a fastening manner or are manufactured as an integral structure, and the matching and restricting relationship between the transmission piece and the fork handle is that the transmission piece and the external gear are in rotating fit; or the matching constraint relation between the transmission piece and the external gear is the relation that the transmission piece and the external gear are in rotating fit, and the matching constraint relation between the transmission piece and the fork handle is the relation that the transmission piece and the fork handle are in fastening connection or are manufactured as an integrated structure; further alternatively, the coupling constraint relationship between the transmission member and the external gear is a rotational fit relationship, and the coupling constraint relationship between the transmission member and the fork is a rotational fit relationship.

Furthermore, the bottom support, the helmet shell main body or/and the external gear are/is provided with a first anti-falling component capable of preventing the internal gear from axially shifting, the internal gear, the bottom support or/and the helmet shell main body are/is provided with a second anti-falling component capable of preventing the external gear from axially shifting, and the internal gear is provided with a third anti-falling component capable of preventing the jaw protection fork from axially loosening.

Furthermore, at least one of the teeth of the external gear is designed to be a special-shaped gear with a tooth thickness larger than the average tooth thickness of all effective teeth on the external gear, and the transmission piece is in matching constraint relation with and only with the special-shaped gear.

Further, the through groove on the internal gear is a flat straight groove type through groove, the straight groove type through groove is distributed to point to or pass through the axis of the internal gear, the sliding constraint pair formed by the mutual sliding fit of the internal gear and the fork handle is a linear constraint type sliding constraint pair, the linear constraint type sliding constraint pair is distributed to point to or pass through the axis of the internal gear, and the straight groove type through groove and the linear constraint type sliding constraint pair are arranged to be overlapped with each other or arranged in parallel with each other.

When the helmet and the jaw protector are in the whole helmet structure position, the rotation axis of the rotation surface structure of the transmission part of at least one of the related mechanisms is in a position coincident with the axis of the inner gear, and the linear constraint element contained in the sliding constraint pair of the related mechanism is perpendicular to the plane formed by the axis of the inner gear and the axis of the outer gear.

Further, the central angle α encompassed by all of its active gears in the internal gear is greater than or equal to 180 degrees.

Further, be provided with first screens structure on the foretell collet or/and the helmet shell main part, be in simultaneously the body of internal gear on or its extension body on seted up at least one second screens structure, and the collet on or/and the helmet shell main part on still be provided with the oppression and order about first screens structure and paste and lean on the effect spring to second screens structure, first screens structure and second screens structure adopt each other to be the structure that stops of public female configuration matched stack, when first screens structure and second screens structure form to stop each other that they can produce the jamming and stop and protect the effect of jaw when the position and gesture.

Further, the first locking structure is in a convex tooth configuration, the second locking structure is in a concave groove configuration, and the second locking structure is configured as follows: the calling jaw protector is provided with a second clamping structure which is clamped with the first clamping structure when in the position of the full helmet structure, and the calling jaw protector is also provided with a second clamping structure which is clamped with the first clamping structure when in the position of the half helmet structure.

Furthermore, when the helmet is in the face-uncovering structure position, the jaw guard is also provided with a second clamping structure which is clamped with the first clamping structure.

Furthermore, the bottom support or/and the helmet shell main body are/is provided with a lifting-assisting spring, when the jaw protection is in the full-helmet structure position, the lifting-assisting spring is in a state of pressing energy storage, when the jaw protection overturns from the full-helmet structure position to the dome of the helmet shell main body, the lifting-assisting spring is in a state of releasing elastic force to assist in pushing the jaw protection to be lifted, and when the jaw protection is in a state between the half-helmet structure position and the uncovering structure position, the lifting-assisting spring can stop generating acting force on the jaw protection.

The helmet has at least one association mechanism in which the ratio of the total circumferential equivalent number of teeth ZR of the internal gear of the meshing element included in the internal gear to the total circumferential equivalent number of teeth Zr of the external gear of the meshing element included in the external gear satisfies the relational expression ZR/Zr-2.

The helmet has at least one associated mechanism with a web-like structural web on the outer gear.

The helmet has at least one association mechanism which is provided with a through groove on the internal gear and participates in the sliding restraint action of the internal gear and the fork handle, and the sliding restraint action is formed as a part or the whole of a sliding restraint pair consisting of the internal gear and the fork handle.

The helmet is provided with a protective cover which comprises two support legs, wherein the two support legs are respectively arranged on two side surfaces of the helmet shell main body and can do fixed-axis swinging motion relative to the helmet shell main body, and at least one support leg is provided with a bearing rail edge, and the support leg provided with the bearing rail edge is arranged between the bottom support and the helmet shell main body; a through opening is arranged on the inner supporting plate of the bottom support facing the helmet shell main body, and a trigger pin which extends out of the opening and can touch the supporting leg force bearing rail edge is arranged on the outer gear; when the protective cover is in a complete buckling and closing state, the layout of the trigger pin and the bearing rail side meets the following conditions: if the jaw guard starts from the complete full helmet structure position and performs the opening action, the trigger pin must be capable of touching the force bearing rail edge on the protective cover supporting leg and driving the protective cover to generate the turning and opening action, and if the jaw guard starts from the complete half helmet structure position and returns to the full helmet structure position, the trigger pin must be capable of touching the force bearing rail edge on the protective cover supporting leg during the first two thirds returning period of the whole returning period of the jaw guard and driving the protective cover to generate the turning and opening action.

The support legs of the helmet shield are provided with first tooth-shaped locking teeth, the bottom support or/and the helmet shell main body are/is provided with second locking teeth corresponding to the first locking teeth, the bottom support or/and the helmet shell main body are/is provided with locking springs, the first locking teeth move synchronously along with the shield, the second locking teeth can move or swing relative to the helmet shell main body, when the shield is in a buckled state, the second locking teeth can be attached to the first locking teeth under the action of the locking springs so that the shield can obtain a weak locking effect, and when the shield is driven by external force to open, the first locking teeth can forcibly drive the second locking teeth to press the locking springs to generate displacement and accordingly perform yielding unlocking action on the first locking teeth.

The utility model relates to a gear-constrained helmet with a variable jaw-protecting structure, which adopts the layout form that a jaw-protecting mechanism, an internal gear, an external gear and a transmission part form a related mechanism, the internal gear and the external gear both rotate around a fixed axis and are mutually meshed to form a motion-constrained pair, meanwhile, the inner gear is provided with a restraint pair in sliding fit with the jaw-protecting fork handle, the inner gear and the outer gear can be mutually driven to generate rotary motion, and drives the jaw handle to generate reciprocating displacement motion relative to the inner gear by a transmission piece which is matched and connected with the outer gear and the jaw protection jaw handle, therefore, the position and the posture of the jaw protector can be restrained to be exactly changed along with the opening or closing action of the jaw protector, the conversion of the jaw protector between the full helmet structure position and the half helmet structure position is finally realized, and the uniqueness and the reversibility of the geometric locus of the jaw protector can be kept. Based on above-mentioned associated mechanism's overall arrangement form and operation, the utility model discloses at the in-process that protects the jaw and transform the position appearance, can make the body of protecting the jaw fork handle follow the internal gear synchronously and make rotary motion together, thereby can basically even cover the logical groove on the internal gear completely, both can avoid outside foreign matter to get into the restraint pair and guarantee the reliability that the helmet used from this, can also block off the inside route of external noise invasion helmet and improve the travelling comfort that the helmet used, it is also less than its shared operating space of dead axle pivoted external gear simultaneously, the event provides more nimble overall arrangement selection for the fastening structure of collet, also consequently can improve the support rigidity of collet and improve the whole security of helmet.

Drawings

Fig. 1 is an axial view of a gear-constrained variable jaw guard helmet of the present invention;

fig. 2 is a side view of the gear-constrained variable jaw structure helmet of fig. 1 in a full helmet configuration;

fig. 3 is a side view of the gear-constrained variable jaw structure helmet of fig. 1 in a half-helmet configuration;

fig. 4 is an exploded view of the gear-constrained helmet with a variable jaw guard structure according to the present invention shown in fig. 1;

fig. 5 is a schematic view of the process state of the gear-constrained variable jaw-protecting helmet of the present invention when the jaw-protecting structure changes from the position of the full helmet structure to the position of the half helmet structure;

fig. 6 is a schematic view of the process status of the gear-constrained variable jaw-protecting helmet of the present invention when the jaw-protecting structure returns from the half-helmet structure position to the full-helmet structure position;

fig. 7 is an axial view of an embodiment of an inner support plate of a bottom bracket of a gear-constrained variable jaw guard helmet according to the present invention;

FIG. 8 is a schematic view of the inner support plate of FIG. 7 viewed along the inner gear axis from the helmet shell body inside the helmet to the outside of the helmet;

FIG. 9 is a schematic view of the inner support plate of FIG. 7 viewed along the axis of the inner gear from the exterior of the helmet to the main body of the shell of the helmet;

fig. 10 is an axial view of an embodiment of the outer support plate of the bottom support of the gear-constrained variable jaw guard helmet of the present invention;

FIG. 11 is a schematic view of the outer support plate of FIG. 10 as viewed along the axis of the inner gear from the shell body of the helmet interior to the direction of the helmet exterior;

FIG. 12 is a schematic view of the outer support plate of FIG. 10 as viewed along the axis of the inner gear in a direction from the exterior of the helmet toward the main body of the shell of the helmet;

fig. 13 is an isometric view of the internal gear of the gear-constrained variable jaw guard helmet of the present invention;

FIG. 14 is an isometric view of the inner gear embodiment of FIG. 13 from another direction;

FIG. 15 is a schematic view of the internal gear of FIG. 13 viewed along an internal gear axis from outside the helmet to the main body of the shell of the helmet;

FIG. 16 is a schematic view of the internal gear of FIG. 13 viewed along an internal gear axis from the shell body inside the helmet to the outside of the helmet;

fig. 17 is an isometric view of the external gear of the gear-constrained variable jaw guard helmet of the present invention;

figure 18 is an isometric view of the embodiment of the outer gear of figure 17 taken in another direction;

figure 19 is a schematic view of the outer gear of figure 17 viewed along the axis of the outer gear from the exterior of the helmet to the main body of the shell of the helmet;

fig. 20 is a schematic view of the external gear of fig. 17 viewed along the axis of the external gear from the helmet shell body inside the helmet to the outside of the helmet;

FIG. 21 is a schematic axial view of an embodiment of the jaw guard and the handle structure of the present invention;

fig. 22 is a side view of the embodiment of the chin bar of fig. 21 and its fork;

FIG. 23 is a side elevational view of the jaw guard and its fork with the embodiment of FIGS. 21 and 22 assembled with a buckle cover;

FIG. 24 is an axial view of an embodiment of a buckle cover of the jaw guard handle of the present invention;

fig. 25 is a schematic view of the buckle cover shown in fig. 24, as viewed from the helmet shell main body inside the helmet to the outside of the helmet;

fig. 26 is a cross-sectional schematic view of an assembled embodiment of the internal gear, external gear, jaw guard fork handle and its buckle cover of the present invention;

fig. 27 is a schematic diagram of the engagement of the gear-constrained helmet with a variable jaw guard according to the present invention, wherein the ratio of the pitch radius R of the internal gear to the pitch radius R of the external gear is designed according to the 2:1 parameter rule;

fig. 28 is a schematic diagram showing the state change of the internal gear and the external gear according to the present invention, when the ratio of the pitch radius R of the internal gear to the pitch radius R of the external gear is designed according to the parameter R/R being 2:1, the through groove of the internal gear is in a straight strip shape, and the through groove is rotated to an arbitrary position from the initial position perpendicular to the plane formed by the axis of the internal gear and the axis of the external gear;

FIG. 29 is a simplified schematic illustration of the geometry of the embodiment shown in FIG. 28;

fig. 30 is a schematic diagram of the internal gear meshing element of the present invention when the full-circumference equivalent tooth number ZR of the internal gear is converted and converted, and the ratio between the full-circumference equivalent tooth number ZR of the external gear and the full-circumference equivalent tooth number ZR of the external gear included in the meshing element satisfies the relation ZR/ZR ═ 2;

fig. 31 is a diagram showing a state of a change in a relative position relationship between the transmission member and the constraint slide rails of the gear constraint type variable jaw protection helmet according to the present invention, wherein the parameters of the internal gear and the external gear satisfy a relationship between an internal gear pitch circle radius R and an external gear pitch circle radius R, which is R/R ═ 2:1, or satisfy a relationship between an internal gear full-circumference equivalent tooth number ZR and an external gear full-circumference equivalent tooth number ZR, which is ZR/ZR ═ 2;

fig. 32 is a schematic diagram of a gear-constrained variable jaw-protecting helmet according to the present invention, in which the jaws of the gear-constrained variable jaw-protecting helmet are respectively engaged with the first engaging structure and the second engaging structure when the gear-constrained variable jaw-protecting helmet is in the full-helmet structural position state, the uncovering structural position state, and the half-helmet structural position state;

fig. 33 is a side schematic view and an axis schematic view showing the mutual linkage of the inner gear, the trigger pin, the shield leg and the force-bearing rail side in the process of lifting the shield at the initial position in the complete buckling position when the jaw is advanced from the full helmet structure position to the half helmet structure position in the gear-constrained variable jaw-protecting structure helmet of the present invention;

fig. 34 is a side view and an axis view of the gear-constrained variable jaw-guard helmet of the present invention, wherein the inner gear, the trigger pin, the guard leg and the force-bearing rail are in linkage with each other when the jaw guard returns from the half-helmet structural position to the full-helmet structural position to open the guard at the initial position in the fully-buckled position;

fig. 35 is a schematic diagram showing a state change of the gear-constrained variable jaw-protecting helmet of the present invention during the unlocking process of the shield at the initial position in the fully-buckled position when the jaw-protecting is advanced from the full-helmet structural position to the half-helmet structural position;

fig. 36 is a schematic diagram illustrating a state change of the gear-constrained helmet with a variable jaw protection structure during the process of unlocking the shield at the initial position, wherein the jaw protection of the gear-constrained helmet with the variable jaw protection structure returns from the half-helmet structure position to the full-helmet structure position.

Detailed Description

The invention will now be further described with reference to specific embodiments, with reference to figures 1 to 36:

a gear-constrained helmet with a variable jaw-protecting structure comprises a helmet shell main body 1, a jaw-protecting structure 2 and two bottom supports 3, wherein the two bottom supports 3 are respectively arranged on two side surfaces of the helmet shell main body 1, and the two bottom supports 3 are fastened on the helmet shell main body 1 (as shown in figures 1 and 4), or the two bottom supports 3 and the helmet shell main body 1 are made into an integrated structure (not shown in the figures), and herein, the connection between the two bottom supports 3 and the helmet shell main body 1 in the utility model includes but is not limited to the following four situations: 1) the two underwires 3 are separate components and are simultaneously fastened to the helmet shell body 1 (as shown in fig. 1 to 4), 2) the two underwires 3 are simultaneously and completely made integral with the helmet shell body 1 (not shown in the figures), 3) the two underwires 3 comprise simultaneously a part of the underwires 3 made integral with the helmet shell body 1 and the other part of the underwires made as a separate member (not shown in the figures), 4) one of the underwires 3 is fastened to the helmet shell body 1 and the other underwire 3 is made integral with the helmet shell body 1 (not shown in the figures); in addition, the term "the two bottom supports 3 are respectively arranged on the two side surfaces of the helmet shell main body 1" in the present invention means: the two bottom supports 3 are disposed beside the symmetry plane P of the helmet shell body 1, wherein the symmetry plane P passes through the mouth, nose and skull top of the wearer and separates the eyes, ears and the like of the wearer beside the symmetry plane P when the wearer normally wears the helmet, i.e. the symmetry plane P is an imaginary plane having the properties of the middle helmet shell body 1 (as shown in fig. 1), in other words, the symmetry plane P of the present invention can be regarded as a left-right symmetry plane of the helmet shell body 1, wherein the symmetry plane P forms an intersection line S with the outer contour surface of the helmet shell body 1 when penetrating through the helmet shell body 1 (see fig. 1 and 4), the best layout of the bottom supports 3 of the present invention is that it is disposed at the side of the helmet shell body 1 (as shown in fig. 1 to 4) adjacent to or beside the ears of the helmet wearer; the jaw guard 2 of the present invention has two prongs 2a (see fig. 4 and 21), and the two prongs 2a are disposed on both sides of the helmet main body 1 (as shown in fig. 4), that is, the two prongs 2a are disposed on both sides of the plane of symmetry P of the helmet main body 1, wherein it is preferred that the prongs 2a have portions of their bodies disposed on or extended to the sides of the helmet main body 1 near or beside the ears of the helmet wearer (as shown in fig. 1 to 4), wherein the prongs 2a can be the body of the jaw guard 2 or an extension of the body, and in particular the prongs 2a can also be relatively independent parts fastened or connected to the body of the jaw guard 2 (including the body's extension or extension), that is, the prongs 2a of the present invention include both a part of the body of the jaw guard 2 and other parts fastened to the body of the jaw guard 2, the fork 2a shown in fig. 4 and 23 is composed of a body extension body of the jaw guard 2 and a buckle cover 2b fastened on the body extension body, so that when the fork 2a includes the buckle cover 2b, the present invention can also mark the fork 2a as 2a (2b) in the figures; it should be noted that the bottom bracket 3 of the present invention may be a component assembled or combined by several components (as shown in fig. 4) or a component composed of a single component (not shown in the figure), wherein the bottom bracket 3 of the combined component is the best form, because then it can be made, installed and maintained more flexibly, the bottom bracket 3 is the component assembled by several components in the case shown in fig. 4, the bottom bracket 3 includes an inner supporting plate 3a and an outer supporting plate 3b in the case shown in fig. 4, furthermore, in some drawings of the present invention, for example, the inner supporting plate 3a and the outer supporting plate 3b in fig. 32 may also be identified as the bottom bracket 3(3a) and the outer supporting plate 3b may also be identified as the bottom bracket 3(3 b); it should be noted that the helmet shell main body 1 of the present invention is a generic term, and it may be only the helmet shell main body 1 itself, or may include various other parts fastened and attached to the helmet shell main body 1 itself, and the parts include various functional parts or decorative parts such as a louver, a cover, a suspension member, a sealing member, a fastening member, and an energy absorbing member; the utility model discloses a characteristic lies in: an internal gear 4 constrained by the base support 3 and/or the helmet shell body 1 and an external gear 5 constrained by the base support 3 and/or the helmet shell body 1 are respectively provided corresponding to each base support 3 (see fig. 4, 13 to 20), the internal gear 4 rotates around its internal gear axis O1 and the external gear 5 rotates around its external gear axis O2 (see fig. 28 and 29), wherein the internal gear 4 and the external gear 5 are engaged with each other, the internal gear 4 is an internal gear, the external gear 5 is an external gear, and the internal gear 4 and the external gear 5 are engaged with each other, and therefore the engagement between the internal gear 4 and the external gear 5 in the present invention belongs to the category of gear transmission with internal gearing, it is worth mentioning that the internal gear 4 and the external gear 5 in the present invention can be cylindrical gears (see fig. 4, b, c, Fig. 14, 16 to 19, 27 and 28) may be a non-cylindrical gear (not shown), and in which the inner gear 4 and the outer gear 5 are both cylindrical gears, which is the most preferred form, and when they are cylindrical gears, the inner gear axis O1 is an axis passing through the center of the pitch circle of the inner gear 4, and the outer gear axis O2 is an axis passing through the center of the pitch circle of the outer gear 5, where the center of the pitch circle of the inner gear 4 coincides with the center of the pitch circle of the inner gear 4, and the center of the pitch circle of the outer gear 5 coincides with the center of the pitch circle of the outer gear 5, and the present invention particularly includes the most preferred arrangement that the inner gear axis O1 and the outer gear axis O2 are arranged parallel to each other and are perpendicular to the symmetry plane P of the helmet shell body 1; it should be noted that the action of the inner gear 4 and the outer gear 5 of the present invention that make the fixed axis rotation may be generated under the constraint of the bottom support 3 or/and the helmet shell main body 1, or may be generated under the constraint of other forms besides the constraint of the bottom support 3 or/and the helmet shell main body 1, for example, the outer gear 5 is constrained by the bottom support 3 or/and the helmet shell main body 1 and also constrained by the mutual engagement between the inner gear 4 and the outer gear 5 to make the fixed axis rotation as shown in fig. 4, wherein: the internal gear 4 and the external gear 5 are not only constrained by the surrounding of the peripheral edge 3c of the base 3 but also constrained by the meshing action between the two gears (see fig. 4 and 32), and therefore, the internal gear 4 and the external gear 5 in fig. 4 have the fixed-axis rotation behavior under the condition of multi-component combined constraint, in fact, because the base 3 in the embodiment shown in fig. 4 embraces and constrains the peripheral edge 3c of the internal gear 4 or the peripheral edge 3c of the external gear 5, the peripheral edges 3c form the surrounding constraint situation of more than 180 degrees on constrained objects, that is, even depending on the constraint of the peripheral edges 3c, the internal gear 4 and the external gear 5 can be constrained to make the fixed-axis rotation behavior, but only the meshing action of the two gears is compounded under the constraint of the peripheral edges 3c, It is possible to obtain a more stable and reliable fixed-axis rotation of these gears, whereas if the peripheral edge 3c does not form an encirclement over more than 180 degrees for the subject to be restrained, i.e. for the internal gear 4 or for the external gear 5 (not shown in the figures), it is obviously necessary to constrain the meshing of the internal gear 4 and the external gear 5 or to constrain other components, so as to reliably complete the fixed-axis rotation of the subject to be restrained, where the peripheral edge 3c may be a part of the body of the shoe 3 (the peripheral edge 3c shown in fig. 4, 7 and 9 is a body forming part of the inner plate 3a of the shoe 3), or a separate component (not shown in the figures) fastened to the shoe 3, and further, for a certain gear, the number of peripheral edges 3c that constrain it may be one or several, or, the shape of the surrounding edge 3c can be set according to the specific structural layout, for example, in the case shown in fig. 4, 7 and 9, the surrounding edge 3c for restraining the internal gear 4 is a closed ring-shaped embankment (some gaps are allowed on the ring-shaped surrounding edge 3 c), and the surrounding edge 3c for restraining the external gear 5 is a semi-enclosed open ring-shaped circular arc embankment (some gaps are allowed on the circular arc embankment 3 c), actually, the surrounding edge 3c in the present invention can be other structural forms such as a boss, a convex key, a convex column, a lug and the like besides the ring-arc structure, and the layout can be a continuous structural form or an intermittent structural form, for example, three contact points distributed in an acute triangle (i.e. the triangle formed by the three points when the three points are used as vertexes) are used as the restraining component, the effect of forming the fixed axis behavior by the constraint of the fixed axis behavior and the fixed axis behavior obtained by adopting the surrounding edge which surrounds more than 180 degrees to carry out constraint are equivalent to both the fixed axis behavior and the fixed axis behavior; it should be noted that, in addition to the structure and construction mode of the above-mentioned surrounding edge 3c to constrain the inner gear 4 and the outer gear 5, the present invention can also constrain the rotation of the inner gear 4 and the outer gear 5 by a mode including a shaft/hole structure or a shaft/sleeve structure, and the inner gear 4 and the outer gear 5 can be constrained to rotate with a fixed axis by relying on the shaft/hole structure or the shaft/sleeve structure, for example, a structure (the holes and the sleeves can be complete or incomplete) of forming holes or sleeves on the base plate 3, and a shaft structure (not shown) rotationally matching with the holes or sleeves is formed on the inner gear 4 or/and the outer gear 5, so as to constrain the fixed axis of the corresponding inner gear 4 or outer gear 5, even only by means of these constraints, the purpose of constraining the internal gear 4 and the external gear 5 to rotate about the fixed axis can be achieved, of course, the axis of the shaft provided on the internal gear 4 must be identical to the axis O1 of the internal gear and should be coaxial with the hole or sleeve provided on the shoe 3 and matched therewith, and the axis of the shaft provided on the external gear 5 must be identical to the axis O2 of the external gear and should be coaxial with the hole or sleeve provided on the shoe 3 and matched therewith, and for the same reason, a shaft-like structure may be provided on the shoe 3 and a hole or sleeve provided on the internal gear 4 or/and the external gear 5 is provided with a structure (not shown) matched therewith (the principle is similar to that, and will not be described herein again; the inter-meshing engagement of the internal gear 4 and the external gear 5 means that they are engaged with each other by a toothed structure or structure and realize transmission and conveyance of motion and power based on meshing, and the effective gear teeth of them may be distributed over a full circumference, that is, over 360 degrees, with effective gear teeth (for example, the external gear 5 in the case shown in fig. 4, 17, 19, 27 and 28 belongs to this case), or may be distributed over a full circumference, that is, without the indexing arc length allocated and occupied by the effective gear teeth of them being 360 degrees (for example, the internal gear 4 in the case shown in fig. 4, 14, 16, 27 and 28 belongs to this case), wherein the effective gear teeth refer to gear teeth substantially participating in meshing constraint (it includes teeth and tooth spaces, the same below), and further, the effective gear teeth of the internal gear 4 and the external gear 5 in the present invention may be evaluated by modulus or have tooth shape thereof The present invention allows for the occurrence of individual or some shaped teeth or shaped tooth spaces (see the shaped tooth spaces 8b and the modified tooth spaces 8c in fig. 14, 16, 27 and 28) in all the effective teeth of the inner gear 4, while allowing for the occurrence of individual or some shaped teeth or shaped tooth spaces (see the shaped tooth spaces 8b and the modified tooth spaces 8c in fig. 14, 16, 27 and 28) in all the effective teeth of the outer gear 5, while allowing for the occurrence of individual or some shaped teeth or shaped tooth spaces in all the effective teeth of the outer gear 5, when the effective teeth of the inner gear 4 and the outer gear 5 are measured or evaluated using a module (e.g., when both the meshing gears are involute gears) in which the modules of the teeth are in one-to-one mating engagement with each other The shaped tooth spaces (see the shaped tooth 8a in fig. 17 to 18, 27 and 28), or the gear phenomenon in which the inner gear 4 and the outer gear 5 exhibit different tooth thicknesses or different tooth space widths when viewed or measured from the pitch circle, are allowed, and it is the case that the shaped tooth space 8b occurs in the inner gear 4 and the shaped tooth 8a occurs in the outer gear 5, the case that the shaped tooth space 8b occurs in the inner gear 4 in the form of a tooth space and the shaped tooth 8a occurs in the form of a tooth space in the outer gear 5, and the shaped tooth 8a in the outer gear 5 and the shaped tooth space 8b in the inner gear 4 belong to the constraint objects of the mating engagement with each other, and further, the case that the modified tooth 8c of the tooth form occurs in the inner gear 4 among the cases shown in fig. 27 and 28, it will be readily appreciated that the above-mentioned shaped teeth 8a and corrected teeth 8c not only have different tooth shapes but also have different tooth shapes from those of other normal valid teeth, i.e. if the shaped teeth 8a and corrected teeth 8c can be measured by modulus, the modulus of the shaped teeth and corrected teeth will be different from each other and the modulus of the modified teeth and corrected teeth will be different from that of other normal valid teeth; it should also be noted that the present invention also specifically includes a situation that allows the inner gear 4 and the outer gear 5 to have individual or several non-geared meshing actions during the meshing movement, that is to say during certain intervals, segments or processes in which the inner gear 4 and the outer gear 5 normally mesh, allowing the interposition of some form of engagement with non-geared members of transitional nature, such as those employing post/groove type engagement, key/groove type engagement, cam/female type engagement or the like, the sizes of the meshing members in the non-gear form can be evaluated by adopting a modulus or not, in other words, the sizes of the meshing structures of the meshing members in the non-gear form can also be measured by adopting other non-modulus forms for the meshing; it should be pointed out that the special-shaped gear teeth 8a, the special-shaped tooth spaces 8b and the correction gear teeth 8c in the utility model can be a traditional gear form which measures the tooth form or tooth space size by using a module, or a non-gear form meshing component which measures the tooth form or tooth space size without using the module; it should also be noted that although the present invention may include the form of engagement of the non-geared members, the engagement of these non-geared members is merely a transitional engagement as an auxiliary property, and the posture switching mechanism that guides and restrains the jaw guard 2 to make the change of the telescopic position type displacement and the swing angle type posture is still mainly restrained and realized by the geared engagement, and therefore it does not substantially change the property and behavior of the gear-restrained variable jaw guard structure of the present invention; it should be particularly noted that the tooth profiles of the effective teeth of the inner gear 4 and the outer gear 5 which are engaged with each other in the present invention include tooth profiles of various gear configurations in the prior art, such as tooth profiles obtained by various creation methods, such as a generating method, a profiling method, etc., and tooth profiles obtained by various manufacturing methods, such as manufacturing using various dies, wire cutting manufacturing, electric discharge manufacturing, three-dimensional forming manufacturing, etc., and the tooth profiles of these teeth include, but are not limited to, involute tooth profiles, cycloid tooth profiles, hyperbolic tooth profiles, etc., and among these tooth profiles, involute tooth profiles are the most preferable (in the case where the gears shown in fig. 4, 14, 16, 17 to 18, 27, and 28 are involute tooth profiles), because the manufacturing cost of the involute gears is relatively low and the installation and adjustment thereof are relatively easy, in addition, the involute gear teeth can be in a straight gear form or a helical gear form; the present invention provides a through groove 6 on the body of the internal gear 4 or its attachment piece, wherein the through groove 6 can be provided on the body of the internal gear 4 (as shown in fig. 4, 13-16) or on the attachment piece (not shown in the figure) fixed on the internal gear 4, wherein the attachment piece is other parts fastened on the internal gear 4. it should be noted that, the through groove 6 of the present invention has a through property, that is, if the through groove is observed along the axial direction of the internal gear axis O1, the through groove 6 can be found to be in a through form (see fig. 4, 13-16, 27, 28 and 30) which can be seen through, and here, the shape of the through groove 6 (the shape obtained by axially observing the internal gear axis O1) can be in various forms, wherein the through groove 6 in a strip form, particularly in a straight strip form, is the best form (see fig. 4, 13-16, 27, 28 and 30) Fig. 13 to 16, 27, 28 and 30), because the straight strip-shaped through slot 6 has the simplest structure, and the straight strip-shaped through slot 6 occupies less space, which creates advantages for concealing, hiding, shielding and covering; in addition, the utility model discloses still be provided with a driving medium 7 (refer to fig. 4 and 31) that passes through said through-groove 6, this driving medium 7 it can be arranged in between external gear 5 and fork 2a, and it can run through the body of internal gear 4 or its attachment and respectively with external gear 5 and fork 2a contact, in the utility model, the collet 3, fork 2a, internal gear 4, external gear 5, driving medium 7 that are located the same side of the helmet shell main part 1 make up a associative mechanism together, that is to say these spare parts that make up this same associative mechanism have between them or structural assembly relation, or have the orbit constraint relation, or have the position to lock the relation, or have the motion fit relation, or have strength transmission relation, etc.; it should be noted that, in the present invention, the driving member 7 at least includes or at least has two ends, that is, the driving member 7 has at least two ends capable of cooperating with external components, and it should be noted that, the driving member 7 of the present invention may be in the form of a single component or in the form of a combined component composed of two or more components, and when the driving member 7 is a combined component, the components may be in the form of a combination of fastening and cooperating with each other, or in the form of a combination of movably cooperating with each other, and in particular, they may also be in the form of a combination of rotating relatively to each other, and in addition, the driving member 7 of the present invention includes two cases: 1) the transmission member 7 is fastened to the external gear 5 (including the case where the transmission member 7 and the external gear 5 are made as an integral structure as shown in fig. 4, 17 to 19), and 2) the transmission member 7 is fastened to the fork handle 2a (including the case where the transmission member 7 and the fork handle 2a are made as an integral structure, not shown in the drawings), wherein as mentioned above, the fork handle 2a of the present invention may be either an integral component, i.e., it has a handle body structure of a single structure, or the fork handle 2a may be a component assembled by several components, i.e., it has a handle body structure of a combined structure (as shown in fig. 4 and 23), and in fig. 4 and 23, the fork handle 2a actually includes a body (including an extension of the body) of the chin bar 2 and a buckle cover 2b fastened to the body, thus, the fastening of the transmission element 7 to the fork 2a includes both the fastening of the transmission element 7 directly to the body of the fork 2a (i.e. to the body of the chin bar 2 or to an extension thereof, not shown in the figures) and the fastening of the transmission element 7 to the constituent parts of the fork 2a (not shown in the figures); in the same related mechanism of the present invention, the fork 2a is disposed outside the through slot 6 on the inner gear 4, the outer gear 5 and the inner gear 4 are engaged with each other and constitute a motion constraint pair, the inner gear 4 and the fork 2a are slidably engaged with each other and constitute a sliding constraint pair, the transmission member 7 has one end thereof engaged with the outer gear 5 and enables the transmission member 7 to receive the driving of the outer gear 5 or vice versa to enable the outer gear 5 to receive the driving of the transmission member 7 through the constraint relationship, the transmission member 7 has another end thereof engaged with the fork 2a and enables the fork 2a to receive the driving of the transmission member 7 or vice versa to enable the transmission member 7 to receive the driving of the fork 2a through the constraint relationship, wherein the motion constraint pair constituted by the outer gear 5 and the inner gear 4 belongs to the gear constraint pair, For convenience of description, the sliding constraint pair of the present invention is generally referred to as a first sliding track a (see fig. 4, 13 to 16, 31) and the elements of the internal gear 4 participating in the sliding constraint pair as a second sliding track B (see fig. 4, 21, 22 and 31), and these first sliding track a and second sliding track B are correspondingly slidably engaged and form the sliding constraint pair (see fig. 26), so that the purpose of constraining the internal gear 4 and the fork handle 2a to realize their relative sliding motion can be achieved, and it should be noted that the sliding constraint pair of the present invention actually includes various sliding constraint pairs of groove track type and various sliding constraint pairs of guide rail type in the prior art, the number of the groove rails or the guide rails of the groove rail type sliding constraint pair or the guide rail type sliding constraint pair can be one or more, in particular, the first slide rail a and the second slide rail B can be paired to form the sliding constraint pair in a one-to-one correspondence manner (i.e. each first slide rail a has and only one second slide rail B to be in sliding fit with the second slide rail B, and each second slide rail B also has and only one first slide rail a to be in sliding fit with the second slide rail B), or the sliding constraint pair can not be paired in a one-to-one correspondence manner (i.e. each first slide rail a can be simultaneously in sliding fit with a plurality of second slide rails B, or vice versa each second slide rail B can be simultaneously in sliding fit with a plurality of first slide rails a); it should be emphasized that, in the present invention, the roles of the first slide rail a and the second slide rail B are interchangeable, that is, the first slide rail a and the second slide rail B can be exchanged in terms of structural features and functional features, wherein the constraint effects obtained by the roles before and after exchanging on the motion constraint and the trajectory constraint of the jaw guard 2 are equivalent or equivalent, taking the structural features as an example: if the original first slide rail A appears in a groove structure form and the original second slide rail B appears in a convex rail structure form and the first slide rail A and the second slide rail B are matched with each other, the first slide rail A and the second slide rail B can be structurally exchanged in the role that the groove structure of the original first slide rail A is changed into the convex rail structure and the convex rail structure type second slide rail B matched with the original first slide rail A is changed into the groove structure, so that sliding constraint pairs formed by the first slide rail A and the second slide rail B before and after the exchange are equivalent; it should be noted that, in the present invention, the phrase "the fork handle 2a is disposed outside the through groove 6 on the inner gear 4" means: assuming that the jaw protector 2 is observed when being in the position of the full helmet structure or the position of the half helmet structure, and when the jaw protector 2 is advanced from the outside of the helmet to the inside of the helmet (or toward the helmet shell main body 1) along the internal gear axis O1, the jaw protector will first encounter the handle of the fork 2a, then the fork will reach the through groove 6 on the internal gear 4, and finally the helmet shell main body 1, that is, the fork 2a will be located at the outer end of the through groove 6 at a greater distance according to the position distance of the helmet shell main body 1, the utility model discloses a fork 2a is arranged at the outside of the through groove 6, and thus, a good condition can be created for the fork 2a to cover the through groove 6; the utility model discloses in the chin guard 2 and the internal gear 4, external gear 5 and the driving medium 7 that belong to in the same associative mechanism (that is internal gear 4, external gear 5 and the three spare parts of driving medium 7 in the same associative mechanism add a chin guard 2 four spare parts altogether again in addition), these four spare parts their drive and operation logic that carry out include one in the following a), b) and c) three kinds of situations at least: a) firstly, the jaw guard 2 makes an original overturning action, then the jaw guard 2 drives the inner gear 4 through the fork handle 2a to enable the inner gear 4 to generate a rotating motion around a self inner gear axis O1, then the inner gear 4 drives the outer gear 5 through a meshing relation to enable the outer gear 5 to generate a rotating motion around a self outer gear axis O2, then the outer gear 5 drives the fork handle 2a through the transmission piece 7 to enable the fork handle 2a to generate an action and enable the fork handle 2a to generate a sliding displacement relative to the inner gear 4 under the combined constraint of the sliding constraint pair, and finally the jaw guard 2 correspondingly changes the position and the posture along with the overturning process; b) firstly, the internal gear 4 performs the original rotation motion around the internal gear axis O1, then the internal gear 4 drives the jaw guard 2 to generate the corresponding overturning motion through the sliding constraint pair formed by the internal gear 4 and the fork handle 2a (here, the rotation force of the internal gear 4 acts on the sliding constraint pair in the form of a moment and causes the fork handle 2a to generate the rotation motion and further drives the jaw guard 2 to generate the corresponding overturning motion through the moment), at the same time, the internal gear 4 drives the external gear 5 through the meshing relationship and generates rotation about its external gear axis O2, the external gear 5 drives the fork handle 2a through the transmission piece 7 to generate action, and under the combined constraint of the sliding constraint pair, the fork handle 2a generates sliding displacement relative to the internal gear 4, and finally the jaw guard 2 correspondingly changes the position and the posture of the jaw guard along with the overturning process of the jaw guard; c) firstly, the external gear 5 performs the original rotation motion around the external gear axis O2, then the external gear 5 drives the internal gear 4 to rotate around the internal gear axis O1 through the meshing relationship, then on the one hand, the internal gear 4 drives the jaw guard 2 to generate the corresponding overturning motion through the sliding constraint pair formed by the internal gear 4 and the fork handle 2a (here, the internal gear 4 applies the torque action to the sliding constraint pair through the rotation and drives the fork handle 2a to generate the rotation motion through the sliding constraint pair, and further drives the jaw guard 2 to generate the corresponding overturning motion), on the other hand, the external gear 5 drives the fork handle 2a through the transmission piece 7 to move, and under the combined constraint of the sliding constraint pair, the fork handle 2a generates sliding displacement relative to the internal gear 4, and finally the jaw guard 2 correspondingly changes the position and the posture along with the overturning process of the jaw guard. Here, the "turning action" in the present invention means that the jaw protector 2 is angularly rotated with respect to the helmet shell main body 1 during the movement, and includes, but is not limited to, a movement process in which the jaw protector 2 advances from the full helmet structure position to the half helmet structure position, and a movement process in which the jaw protector 2 returns from the half helmet structure position to the full helmet structure position, as follows; the term "original" as used herein refers to the mechanical or movement behavior of the component that is first activated (or the component that is first activated by an external force) among the three components of the chin bar 2, the internal gear 4, and the external gear 5, and is the same as the following description. In addition, the jaw guard 2 of the present invention, and the inner gear 4, the outer gear 5 and the transmission member 7 belonging to one related mechanism, the four components and their driving and operating logics may be any one of the three cases a), b) and c), or a combination of any two of the three cases a), b) and c), or a combination of the three cases a), b) and c), and in particular, may be combined with any one or any two or all three of the three cases a), b) and c), and the driving and operating logics of the above cases may be combined with other driving and operating logics, and the driving and operating logics of the cases a) are the best operating mode of the present invention, Because the driving and operating logic of the situation according to a) is the simplest driving transmission situation (at this moment, the helmet wearer only needs to pull the jaw guard 2 by hand to realize the accurate regulation and control of the pose situation of the jaw guard 2), the following situation of a) is taken as an example to explain in detail again, the utility model discloses the action process of realizing driving and operating by hand: firstly, the helmet wearer manually unlocks the jaw guard 2 at the full helmet structure position or the half helmet structure position or at a certain intermediate structure position, namely the uncovering structure position → secondly, the helmet wearer manually opens or buckles the jaw guard 2 to cause the jaw guard 2 to generate an original overturning action → then the jaw guard 2 drives the inner gear 4 to generate a rotating motion around the inner gear axis O1 through the fork handles 2a thereof → then the inner gear 4 drives the outer gear 5 to generate a rotating motion around the outer gear axis O2 through the meshing relationship → then the outer gear 5 drives the fork handles 2a to generate an action through the transmission piece 7 and to cause the fork handles 2a to generate a sliding displacement relative to the inner gear 4 under the combined constraint of the sliding constraint pair → then the fork handles 2a generate a telescopic motion while rotating around the inner gear axis O1 → finally, the jaw guard 2 correspondingly changes the position and posture thereof along with the overturning progress thereof, from the process of turning over the chin guard 2 demonstrated in this embodiment, it can be easily found that the utility model can realize the telescopic action of the chin guard 2 while opening the chin guard 2 by only applying a simple turning driving action to the chin guard 2, and the mysterious point lies in that it utilizes the principle of gear engagement and derives the reciprocating motion by the transmission member 7, thereby greatly simplifying the complex operation actions that the traditional helmet with variable chin guard structure must simultaneously turn over, pull and press the chin guard 2 (see chinese patent ZL201010538198.0 and spanish patent application ES2329494T 3). It should be noted that the fork handle 2a of the present invention has a reciprocating and telescopic moving property relative to the inner gear 4, that is, the jaw protector 2 and the fork handle 2a thereof of the present invention also have a reciprocating motion relative to the inner gear 4 (equivalent to the jaw protector 2 having a reciprocating motion relative to the helmet shell main body 1) while making a turning motion, and the jaw protector 2 can change its position and posture timely while following the turning process because of the characteristic, as mentioned above, the sliding constraint pair formed by the inner gear 4 and the fork handle 2a of the present invention can be a groove rail type, a guide rail type, or other matching type sliding pair, and the sliding constraint pair formed by the inner gear 4 and the fork handle 2a can be various sliding pair forms of the prior art, in particular, including but not limited to sliding pairs of the sliding channel/slide type, guide rod/guide sleeve type, sliding channel/guide pin type, sliding channel/slide rail type, etc., it means that the jaw guard 2 fork 2a is preferably arranged in such a way that it abuts, abuts or is embedded in the internal gear 4 and that a relative movement can be generated between them. It should be noted that the driving power for driving the jaw guard 2 to perform the original turning motion, the inner gear 4 to perform the original rotation motion, or the outer gear 5 to perform the original rotation motion in the present invention may be from a motor, a spring, or a human hand, wherein the driving power may be in a single driving form or a multiple combined driving form, and it is the most simple and reliable driving form, and at this time, the helmet wearer may directly pull the jaw guard 2 with his hand to turn the jaw guard 2, or directly pull the inner gear 4 with his hand to generate the rotation motion, and then directly pull the outer gear 5 with his hand to generate the rotation motion, besides the direct manual actuation of the relevant components, the helmet wearer can indirectly actuate the jaw guard 2, the inner gear 4 or the outer gear 5 by means of various linkages such as a pull cord, a toggle element, a guide rod, etc., so as to generate the corresponding movement (not shown in the figures). In particular, the term "the inner gear 4 rotates around the inner gear axis O1 and the outer gear 5 rotates around the outer gear axis O2" as used herein, wherein the inner gear axis O1 and the outer gear axis O2 do not require absolute fixed-axis state and absolute straight-axis state in the present invention, but allow the axes to have a certain degree of yaw error and deformation error, i.e. allow the inner gear axis O1 and the outer gear axis O2 to exhibit a certain degree of yaw and distortion condition within a certain error range, i.e. allow the inner gear axis O1 and the outer gear axis O2 to exhibit a certain degree of yaw and distortion condition under the influence of various factors such as manufacturing error, installation error, stress deformation, temperature deformation, vibration deformation, etc., wherein the certain degree of error range means that the final combined effect is an error range that does not affect the normal overturning process of the jaw guard 2, needless to say, the present invention allows the non-parallelism and non-parallelism of the inner gear axis O1 and the outer gear axis O2 to occur in a local area due to various shaping requirements, obstacle crossing requirements, and locking requirements, wherein the "shaping requirements" refer to the reasons that the jaw guard 2 needs to follow the overall appearance of the helmet, "obstacle crossing requirements" refer to the reasons that the jaw guard 2 needs to cross certain limit points such as the highest point, the last point, and the widest point of the helmet, and the "locking requirements" refer to the reasons that the jaw guard 2 needs to elastically adapt to deformation in the full-helmet structure position, the half-helmet structure position, and the uncovering structure position, and in the vicinity of the certain limit points, but the non-parallelism and non-parallelism of the inner gear axis O1 and the outer gear axis O2 due to the above reasons (including the non-parallelism P of the helmet shell body 1 and the locking requirements thereof) Phenomenon), as long as they do not influence the normal overturning operation of the jaw guard 2, the utility model is considered to fall within the allowable error range; it should be noted that the "uncovering structure position" in the present invention refers to a position of the jaw guard 2 at any position between the full helmet structure position and the half helmet structure position, and belongs to an intermediate helmet type, also called uncovering structure helmet (may be referred to as uncovering helmet for short), and the uncovering helmet belongs to a quasi-half helmet structure type helmet, the jaw guard 2 at the uncovering structure position can be expressed in different structural positions such as a slightly-opened degree, a medium-opened degree and a high-opened degree (wherein the slightly-opened degree refers to a state that the jaw guard 2 at the full helmet structure position is defined as zero-opened degree, i.e. not opened at all, and the slightly-opened degree refers to a state that the jaw guard 2 is slightly opened, and the slightly-opened jaw guard 2 is beneficial to breathing and dispersing the breathing water mist in the helmet, the middle opening degree is a state that the jaw guard 2 is opened to the vicinity of the forehead of the wearer, which is beneficial for the wearer to perform activities such as conversation communication and temporary rest, and the high opening degree is a state that the jaw guard 2 is positioned at or near the dome of the helmet shell main body 1, which is particularly suitable for the wearer to drink water, observe or perform other work activities; it should be noted that the chin guard 2 and the fork 2a thereof of the present invention obviously have the same rotating angular velocity relative to the helmet shell main body 1 as the inner gear 4 rotates in the same direction and at the same rotating speed, but the chin guard 2 and the fork 2a thereof are accompanied by the telescopic motion relative to the inner gear 4 while rotating synchronously in accordance with the inner gear 4, it is noted that the through groove 6 is opened on the body of the inner gear 4 or the attachment thereof, and therefore the through groove 6 is also bound to follow the inner gear 4 to perform the synchronous and consistent rotating motion, in other words, the chin guard 2 and the fork 2a thereof of the present invention are actually in synchronous rotating motion together with the through groove 4, and it should be noted that, as mentioned above, the fork 2a and the fork 2a thereof in the same related mechanism are arranged outside the through groove 6 on the inner gear 4, that is to say, the through slot 6 of the present invention has the fork handle 2a which rotates synchronously with the through slot 6 to follow all the time, which means that the jaw guard 2 is in all the overturning processes of opening or buckling, the fork handle 2a of the present invention can be well designed to cover the through slot 6 (see fig. 5 and 6), and it is particularly pointed out that the jaw guard 2 of the present invention has the fork handle 2a to follow the through slot 6 to do synchronous rotation movement, i.e. the fork handle 2a and the through slot 6 have the same angular velocity relative to the helmet shell main body 1, and therefore, the telescopic movement of the fork handle 2a relative to the inner gear 4 is performed along the opening of the through slot 6, and it is noted that the fork handle 2a of the present invention is arranged outside the through slot 6, in other words, even if the handle 2a body structure of the handle 2a with relatively narrow width is used, The utility model discloses in fact also can accomplish the full-time full position ground completely to cover logical groove 6 leisurely, and this is exactly the utility model discloses with the variable jaw structure technique of protecting of current gear restraint such as CN105901820A, CN101331994A, a showing difference in this aspect of WO2009095420A 1. In order to express more clearly the utility model provides a protect 2 processes that change to half helmet structure position from full helmet structure position conversion of jaw, its whole process of change has been given to figure 5: fig. 5(a) shows the corresponding jaw 2 in the full helmet position state of the full helmet structure → fig. 5(b) shows the corresponding jaw 2 in the climbing position state in the lifting process → fig. 5(c) shows the corresponding jaw 2 in the climbing position state across the dome of the helmet shell body 1 (this state also belongs to a face-opened helmet state) → fig. 5(d) shows the corresponding jaw 2 in the falling position state in which the jaw is folded toward the back of the helmet shell body 1 → fig. 5(e) shows the corresponding jaw 2 in the half helmet position state in which the jaw is stored and fallen back to the half helmet structure; in order to express the utility model discloses protect jaw 2 and return and resume the process to full helmet structure position from half helmet structure position equally more clearly, its whole course change process has been given to figure 6: fig. 6(a) shows a half-helmet position state in which the chin rest 2 is in the half-helmet structure → fig. 6(b) shows a state in which the chin rest 2 is in a climbing position to climb to the back of the helmet shell main body 1 on the way of return → fig. 6(c) shows a state in which the chin rest 2 is in an over-top position to cross the dome of the helmet shell main body 1 → fig. 6(d) shows a snap-off position state in which the chin rest 2 is in the end of return → fig. 6(e) shows a state in which the chin rest 2 is in a full-helmet position to return to the full-helmet structure, which is not difficult to find from fig. 5 and 6, in various structural positions of the jaw guard 2 and in various overturning processes of the jaw guard 2, the through groove 6 is completely covered by a handle body with a narrow structure of the fork handle 2a of the jaw guard 2 without being exposed, therefore, the utility model discloses do can accomplish to cover logical groove 6 and make it not expose outward in full time overall process sheltering from completely. The present invention has no doubt, the present invention adopts the structure that the inner gear 4 and the outer gear 5 both make fixed axis rotation and make them engage with each other to form the motion restriction pair, at the same time, the inner gear 4 and the fork handle 2a are set into the form of the sliding restriction pair which is mutually sliding fit, and the transmission member 7 transmits the rotation motion of the outer gear 5 to the fork handle 2a to make it generate the telescopic motion relative to the inner gear 4, thereby realizing the exact change of the position and the posture of the restriction jaw guard 2 along with the action process of opening or closing the jaw 2, finally realizing the reliable conversion of the jaw 2 between the full helmet structure position and the half helmet structure position, obviously, in view of the nature of the gear engagement transmission, the present invention can keep the uniqueness and the reversibility of the operation geometric trajectory of the jaw 2 when changing the posture, namely, a specific and unique posture necessarily be called along with a specific position of the jaw 2, and no matter the inner gear 4 and the outer gear 5 do forward rotation movement or reverse rotation movement, the postures of the jaw guard 2 at a certain specific corner moment are determined uniquely and can be inverted reversibly. Further, the utility model discloses in protect jaw 2's fork 2a it can basically even can cover logical groove 6 on the internal gear 4 completely, both can avoid outside foreign matter to get into the restraint in vice and guarantee the reliability that the helmet used like this, can also block off the inside route of external noise invasion helmet and improve the travelling comfort that the helmet used simultaneously. Still further, the utility model discloses an outer gear 5 is because its motion belongs to the form that the dead axle rotated, in other words, the running space that it occupied of this outer gear 5 is comparatively few relatively, so also lay fastening structure for rigidity and intensity homogeneous phase is relative weak collet 3 and provide more nimble selection, for example can lay structure such as rigid reinforcement muscle and fastening nail on the periphery of outer gear 5 simultaneously at the position such as the inner periphery and periphery of inner gear 4, and these fastening reinforcement measures are not comprehensive enough in the variable chin guard structure technique of the restraint type of current gear, also consequently the utility model discloses can improve the support rigidity of collet 3 and then can improve the whole security of helmet; it is worth mentioning that the prior art gear-constrained variable jaw structure helmets such as CN105901820A, CN101331994A, WO2009095420a1 provide solutions that all adopt the structure and operation of the moving gear or rack that swings and rotates along with the jaw guard 2, and therefore the space swept by the gears or racks is very large, so that the structural design thereof has a negative effect on the rigidity and strength of the helmet, which is a further significant difference between the gear-constrained variable jaw structure helmet of the present invention and the above prior art.

When the inner gear 4 and the outer gear 5 are in the same linked mechanism, the inner gear 5 is in the same rotational relationship with the inner gear shaft 2, the inner gear 5 is in the same rotational relationship with the outer gear shaft 2, the inner gear shaft 2 is in the same rotational relationship with the outer gear shaft 4, the inner gear shaft 2 is in the same rotational relationship with the inner gear shaft 4, the inner gear shaft 2 is in the same rotational relationship with the outer gear shaft 4, the inner gear shaft 4 is in the same rotational relationship with the inner gear shaft 2, the inner gear shaft 5 is in the same rotational relationship with the outer gear shaft 2, the inner gear shaft 5 is in the same rotational relationship with the inner gear shaft 2, the inner gear shaft 2 is in the same rotational relationship with the inner gear shaft 2, the inner gear shaft 5 is in the same rotational relationship with the inner gear shaft 2, the inner gear shaft 2 is in the same rotational relationship with the inner gear 5, the inner gear shaft 2, the same rotational relationship with the inner gear 5, the inner gear shaft 2, the inner gear 5 is in the same rotational relationship with the same rotational direction, the same rotational relationship with the inner gear 5, the inner gear shaft 2, the inner gear 5 is not necessarily, the same rotational direction, the inner gear shaft 2, the inner gear 5 is not necessarily, the same rotational direction, the inner gear 5 is not necessarily, the inner gear 5, the rotational direction, the inner gear 5 is not necessarily, the inner gear 5, the inner gear shaft 2, the inner gear 5 is not necessarily, the inner gear shaft 2, the rotational direction, the inner gear 5 is not necessarily, the rotational direction, the inner gear 5, the rotational direction, the same, the rotational direction, the inner gear 5, the inner gear is not necessarily, the rotational direction, the inner gear shaft is not necessarily, the rotational direction, the outer gear 5, the inner gear is not necessarily, the inner gear 5 is not necessarily, the rotational direction, the straight pitch angle is not necessarily, the straight gear axis is not necessarily, the straight pitch angle is not necessarily, the straight gear axis is not necessarily, the straight pitch angle is not necessarily, the straight gear axis is not necessarily, the straight pitch angle is not necessarily, the straight gear axis is not necessarily the straight pitch angle is not necessarily, the straight gear axis is not necessarily the straight pitch angle is not necessarily the straight gear axis is not necessarily the straight gear axis is not, the straight gear axis is not, the straight gear axis is not, the straight gear axis is not necessarily the straight gear axis is not the straight gear axis is not, the straight gear axis is not necessarily the straight gear axis is not necessarily the straight gear axis is not the straight gear axis is not necessarily the straight gear axis is not, the straight gear axis is not necessarily the straight gear axis is not the straight gear axis is not the straight gear axis is the straight gear is not the straight gear axis is not the straight gear axis is not the straight gear axis is not the straight gear axis is the straight gear axis is the.

In the same linkage mechanism, the transmission member 7 can be designed to be a part including a revolution surface structure, wherein the revolution surface structure includes a revolution axis O3 which always synchronously rotates around the external gear axis O2 along with the external gear 5, and the revolution axis O3 is arranged parallel to the external gear axis O2 and intersects with the pitch circle of the external gear 5 (see fig. 19, 28, 29, 30 and 31); here, the revolution surface may be constructed in various forms including various cylindrical surfaces, conical surfaces, spherical surfaces, toroidal surfaces, and irregular surfaces, etc.; it should be noted that the pitch circle of the external gear 5 is formed when the external gear 5 meshes with the internal gear 4 (at this time, the internal gear 4 will also derive an internal gear pitch circle tangent to the external gear pitch circle at the same time), it is obvious that when the external gear 5 is a standard gear, its external gear pitch circle will coincide with the external gear pitch circle, and when the external gear 5 is a non-standard gear, that is, it is a modified gear whose modification coefficient is not zero, its external gear pitch circle will not coincide with the external gear pitch circle, and similarly, when the internal gear 4 is a standard gear, its internal gear pitch circle will coincide with the internal gear pitch circle, and when the internal gear 4 is a non-standard gear, that is, it is a modified gear whose modification coefficient is not zero, its internal gear pitch circle will not coincide with the internal gear pitch circle; the utility model discloses make the driving medium 7 into the spare part that includes the surface of revolution structure, its purpose is when making this driving medium 7 form to join in marriage with external gear 5 and when driving medium 7 forms to join in marriage with the fork 2a of chin guard 2 and join in marriage and restrict the relation, can let them have better cooperation form and better preparation manufacturability, because the well known part that has the structure of circling round is their forming process simpler, and their assembly is also simpler simultaneously, and they can adopt classic hole axle cooperation form; in addition, the utility model discloses with gyration axis O3 overall arrangement for crossing with the pitch circle of external gear 5 and let it and external gear axis O2 parallel arrangement, its benefit is that can obtain better space layout so that the overall arrangement occupy-place of balanced distribution driving medium 7 among external gear 5, internal gear 4 and logical groove 6 three with this overall arrangement, especially can also make driving medium 7 obtain better motion stability, just as it proves earlier, when the revolution face structure of driving medium 7 has a gyration axis O3 and let its overall arrangement on the pitch circle of external gear 5 and let it and external gear axis O2 parallel arrangement, then its law of operation of this gyration axis O3 will fall on the radius that a certain internal gear is followed the synchronous revolution together of 4 all the time, thereby created good condition for the shape design and the overall arrangement design of logical groove 6; it should be noted that, the above-mentioned rotation axis O3 of the transmission member 7 and the external gear axis O2 of the external gear 5 are arranged in parallel, and the present invention does not require that they are absolutely parallel, but allows some non-parallel errors to exist in these axes, that is, non-parallel conditions between the rotation axis O3 and the external gear axis O2 caused by various factors such as manufacturing errors, installation errors, stress deformation, temperature deformation, vibration deformation, etc., as long as the final comprehensive effect of these non-parallel errors does not affect the normal overturn of the jaw guard 2, the present invention uniformly treats the rotation axis O3 and the external gear axis O2 according to the parallel arrangement requirements. Furthermore, the present invention can design the revolution surface structure of the driving member 7 into a cylindrical surface structure (as shown in fig. 4, 17 to 18, 27, 28, 30 and 31) or design the revolution surface structure of the driving member 7 into a conical surface structure (not shown in the figure), and the driving member 7 at this time obviously has only two ends and only one revolution axis O3, and as is well known, the cylindrical surface structure and the conical surface structure are classical component structure forms, which are not only convenient to process but also very reliable in matching form; it should be noted that the conical surface structure of the present invention includes the structure of a truncated cone, and in addition, the revolution surface structure of the driving member 7 of the present invention can be a cylindrical surface structure with only a single diameter or a cylindrical surface structure with a plurality of different diameters when it is designed to be the cylindrical surface structure (but these cylindrical surfaces must be coaxially arranged, that is, the driving member 7 has only one revolution axis O3), especially, the revolution surface structure of the driving member 7 of the present invention also includes such a situation, that is: on the basis of the cylindrical surface structure or the conical surface structure which plays a matching constraint relation, other types of revolution surface structures such as process structure details with auxiliary properties of chamfering, filleting and coning which are convenient to manufacture, install and avoid stress concentration are compounded, and the premise is that all the process structure details with the auxiliary properties cannot damage the revolution surface structure of the transmission piece 7 which is in the matching constraint relation with the external gear 5 or the fork handle 2 a.

The utility model discloses can adopt the arrangement for one of following three kinds of overall arrangement situations between the driving medium 7 in the same associative mechanism and the external gear 5 and the connection constraint relation between this driving medium 7 and the fork 2 a: 1) the connection constraint relationship between the transmission member 7 and the external gear 5 is a relationship that they are tightly connected or they are made as an integral structure, and at the same time, the connection constraint relationship between the transmission member 7 and the fork handle 2a is a relationship that they are rotationally matched (the case shown in fig. 4 and 17 to 19 is an example that the transmission member 7 and the external gear 5 are made as an integral structure, and at this time, the transmission member 7 has one end which is rotationally matched and constrained with the round hole 2c on the buckle cover 2b in fig. 4 and 24 to 26); or, 2) the coupling constraint relationship between the transmission member 7 and the external gear 5 is a relationship in which they are rotationally fitted, and at the same time, the coupling constraint relationship between the transmission member 7 and the fork 2a is a relationship in which they are fastened or they are made in an integral structure (not shown in the drawings); still alternatively, 3) the coupling constraint relationship between the transmission member 7 and the external gear 5 is adopted as the rotationally engaged relationship, and at the same time, the coupling constraint relationship between the transmission member 7 and the fork 2a is also adopted as the rotationally engaged relationship (not shown in the drawings). In fact, in addition to the above three situations, the present invention also includes or may have other forms of connection constraint relations between the transmission member 7 and the external gear 5 and between the transmission member 7 and the fork handle 2a, such as between the transmission member 7 and the external gear 5 or/and between the transmission member 7 and the fork handle 2a, which can be a rotation fit and a sliding fit, that is, a rotation-sliding connection constraint relation (not shown), a typical example of this is a cylindrical configuration of the transmission member 7, while the structure of the external gear 5 or of the fork 2a with which it is engaged is a kidney-shaped configuration, so that the transmission member 7 can be rotationally engaged with respect to the external gear 5 or the fork 2a while also being capable of sliding engagement with respect to the external gear 5 or the fork 2 a.

The utility model discloses a prevent that jaw protection 2 leads to internal gear 4 and external gear 5 to appear the situation that takes off when its upset to guarantee that jaw protection 2 can remain stability and reliability in the process of transform position appearance, can collet 3, helmet shell main part 1 or/and external gear 5 on set up the first component 9a of only taking off that can prevent that internal gear 4 from appearing the axial position shifting, simultaneously internal gear 4, collet 3 or/and helmet shell main part 1 on set up the second component 9b of only taking off that can prevent external gear 5 from appearing the axial position shifting, here, the so-called axial position shifting that prevents is said, through setting up first component 9a of only taking off and second component 9b of only taking off to prevent, block, prevent and restrict internal gear 4 and external gear 5 and appear excessive aversion and avoid them to appear the action that takes off, that is said and avoid internal gear 4 and external gear 5 they appear the action that influences jaw protection 2 normal upset process and avoid appearing influencing and influence and protect the action that the jaw protection is said 2 normal clamping behaviors at the full helmet structure position, the half helmet structure position and the uncovering structure position; the first anti-drop component 9a in the utility model has the layout of various situations that the first anti-drop component 9a is arranged on the bottom support 3, the helmet shell main body 1 or the internal gear 4, and the first anti-drop component 9a is arranged on any two combinations of the parts of the bottom support 3, the helmet shell main body 1 and the internal gear 4 and all three parts; the second anti-drop component 9b in the utility model has the layout of various situations that the second anti-drop component 9b is arranged on the internal gear 4, the collet 3 or the helmet shell main body 1, and the arbitrary two combinations of the parts of the internal gear 4, the collet 3 and the helmet shell main body 1 and all three parts are provided with the second anti-drop component 9 b; in the case shown in fig. 4, 10 to 12, the first retaining member 9a for preventing the internal gear 4 from axial shifting is provided on the outer plate 3b of the bottom bracket 3, while in the embodiment of fig. 4 and 13 to 16, the second retaining member 9b for preventing the external gear 5 from axial shifting is provided on the internal gear 4, and it is apparent that the arrangement of the first retaining member 9a and the second retaining member 9b in the present invention is not limited to the above-mentioned case shown in fig. 4, 10 to 16; it should be noted that the first and second anti-slip members 9a and 9b of the present invention may be in the form of a flanging structure (as shown in fig. 4 and 10 to 12), a snap structure (i.e. a hook structure, not shown), a snap ring structure (i.e. a snap ring structure, not shown), a clinch structure (i.e. a fastening screw structure, not shown), a pin structure (i.e. a locking pin structure, not shown), a cover structure (as shown in fig. 4 and 13 to 16, wherein the cover structure type second anti-slip member 9b in these illustrations may be a body structure or an extended body structure on the internal gear 4), or even a magnetic attraction member (not shown) or other structures or members, as previously mentioned, the first anti-slip means 9a may be part of the structure of the mounting 3 (as shown in fig. 4, 10 to 12), or of the structure of the shell body 1 (not shown), or of the structure of the external gear 5 (not shown), while the second anti-slip means 9b may be part of the structure of the internal gear 4 (as shown in fig. 4 and 13 to 16), and furthermore, the first anti-slip means 9a may also be a separate component (not shown) fastened to the mounting 3, or to the shell body 1, or to the external gear 5, while the second anti-slip means 9b may be a separate component (not shown) fastened to the internal gear 4, or to the mounting 3, or to the shell body 1; similarly, in order to prevent the jaw protector 2 from being separated from the helmet shell main body 1, the present invention may further provide a third anti-slip member 9c (as shown in fig. 4, 13, 15 and 31) on the internal gear 4, which can prevent the fork handle 2a of the jaw protector 2 from being axially released, wherein the third anti-slip member 9c may be a part of the body (including an extension or an extension of the body) of the internal gear 4 (as shown in fig. 4, 13, 15 and 31), or a separate component (not shown) fastened to the internal gear 4, and may be configured as a flanging configuration (as shown in fig. 4, 13, 15 and 31) or as a configuration (not shown) of a slot, staple, clip, clamping cover, or the like, or as various other prior art configurations, wherein the flanging configuration is preferred, since the flanging configurations are relatively easy to implement in terms of manufacturing and assembly and in particular they can even be formed as part or even all of the sliding constraint pairs between the jaw guard 2 and the fork handle 2a, it should be noted that the flanging configuration of the third anti-slip member 9c featuring the flanging configuration of the present invention can have various configurations, such as the flanging orientation of the third anti-slip member 9c in the flanging configuration shown in fig. 4, 13, 15 and 31 being oriented away from the through slot 6, i.e. the flanging configuration thereof being directed to the outside of the through slot 6, in addition to the fact that the flanging orientation of the third anti-slip member 9c in the flanging configuration of the present invention also includes a configuration (not shown in the figures) directed to the through slot 6, as mentioned above the purpose of the present invention is to prevent the fork handle 2a of the jaw guard 2 from axially disengaging from the internal gear 4, the term "axially disengaged" as used herein refers to the condition in which the fork 2a, which affects the normal tilting of the chin bar 2, is disengaged from the ring gear 4 along the axial direction of the ring gear axis O1. it should be noted that the third anti-disengagement member 9c of the present invention is provided to prevent the fork 2a from axially disengaging from the ring gear 4, but it does not interfere with the reciprocating action of the sliding constraint pair formed by the fork 2a and the ring gear 4.

In order to better arrange the transmission member 7, at least one of the effective teeth of the external gear 5 may be designed as a special-shaped tooth 8a with a tooth thickness larger than the average tooth thickness of all effective teeth of the external gear 5, that is, the special-shaped tooth 8a of the external gear 5 is firstly a solid tooth having the special-shaped tooth 8a in a tooth form, and secondly the tooth form size of the special-shaped tooth 8a is larger than that of other normal effective teeth (as shown in fig. 17 and 19), it is certainly necessary to provide a special-shaped tooth socket 8b in a tooth socket form on the internal gear 4 to be engaged with the special-shaped tooth 8a of the external gear 5, and obviously, the tooth socket width of the special-shaped tooth socket 8b of the internal gear 4 is also correspondingly wider than that of other normal teeth (as shown in fig. 14 and 16), here, the driving member 7 and the external gear 5 only have a matching constraint relationship with the special-shaped gear teeth 8a (see fig. 27 and 28), so that the external gear 5 is provided with the special-shaped gear teeth 8a with a relatively thick tooth form, and the purpose is to obtain a relatively large diameter size for the revolution surface structure of the driving member 7 matched with the special-shaped gear teeth 8a, so that the strength and rigidity of the driving member 7 can be well ensured, and the reliability and safety of the helmet can be improved.

In order to better enable the jaw guard 2 to smoothly and reliably complete various pose conversion processes, the through groove 6 on the internal gear 4 can be designed into a flat straight groove type through groove, namely the through groove 6 is a straight groove type through groove 6, the straight groove type through groove 6 is distributed to point or pass through an internal gear axis O1 (see fig. 15, 16, 27, 28 and 31), in addition, a sliding constraint pair formed by mutual sliding fit of the internal gear 4 and the fork handle 2a is designed into a linear constraint type sliding constraint pair, the linear constraint type sliding constraint pair is distributed to point or pass through an internal gear axis O1, and meanwhile, the straight groove type through groove 6 and the linear constraint type sliding constraint pair are distributed to be mutually overlapped or mutually parallel; here, the through groove 6 is designed as a "flat straight groove type through groove" in such a way that, when viewed in the axial direction of the internal gear axis O1, it can be seen that the through groove 6 is in the shape of a flat long strip and has a straight-edged groove edge configuration and is visible through, and the through groove 6 is arranged so as to point to or pass through the internal gear axis O1 "in such a way that the main body configuration of the through groove 6, if it is projected forward to the helmet symmetry plane P, has its set of projections intersecting the projected focal point of the internal gear axis O1, or the set of projections, if it extends along its geometric symmetry line, must sweep through the projected focal point of the internal gear axis O1, in particular the projected focal point of the symmetry line of the set passing through the internal gear axis O1 (see fig. 15, 16, 27, 28 and 31); here, the phrase "the sliding restraint pair formed by the internal gear 4 and the fork 2a being slidably fitted to each other is designed as a linear restraint type sliding restraint pair" means that the restraining action of the restraint pair has an effect of causing the internal gear 4 and the fork 2a to move relative to each other in a linear displacement manner, and the phrase "the linear restraint type sliding restraint pair is disposed so as to point to or pass through the internal gear axis O1" means a structure, or part (for example, a handle of the fork 2 a) constituting the linear restraint type sliding restraint pair in a state where at least one element thereof points to or passes through the internal gear axis O1 (see fig. 5, 6, and 31); here, the phrase "the straight groove type through grooves 6 and the linear constraint type sliding constraint pairs are arranged so as to overlap with each other or so as to be parallel to each other" means that when the through grooves 6 and the sliding constraint pairs are orthographically projected together toward the symmetry plane P of the helmet, the projections thereof intersect with each other, and particularly, the geometrical symmetry line including the projection set of the straight groove type through grooves 6 and the geometrical symmetry line including the projection set of the linear constraint type sliding constraint pairs in the projection are parallel to each other, and particularly, the projections thereof overlap with each other. The utility model discloses a straight flute type leads to the groove 6 about type slip restraint of collocation straight line is vice and arrange them for the coincidence setting or for such a design layout arrangement of parallel arrangement, can obtain following benefit at least: firstly, the transmission part 7 can smoothly perform non-interference reciprocating movement in the through groove 6, and secondly, conditions can be created for the fork handle 2a to completely shield the through groove 6; as mentioned above, when the moving track of the driving member 7 is of a straight reciprocating nature and can be arranged to always follow the straight-grooved through-groove 6 arranged in the radial direction on the internal gear 4, it is needless to say that the driving member 7 can be freely made to have no moving interference with the through-groove 6 (see fig. 31), and on the other hand, it is noticed that the fork 2a of the jaw guard 2 has the same moving behavior with the internal gear 4 (i.e. with the through-groove 6) in the same angular velocity and the same direction of rotation, and the through-groove 6 can be designed to be flat in fact, which creates conditions for the fork 2a arranged on the outer side and adopting a narrow structure to completely cover the through-groove 6 in the whole time and whole process, in other words, even if the fork 2a of the jaw guard 2a adopts a narrow structure to completely cover the through-groove 6, because the jaw guard 2 can completely cover the through the whole time, whole process and whole cover the through-position of the helmet structure, The fork handle 2a can be well attached to the outer surface of the through groove 6 on the inner gear 4 when the helmet is in a half-helmet structure position or in any other intermediate state position of the turning process, such as a uncovering structure position.

The utility model discloses an improve the upset degree of protecting jaw 2 and require and the aerodynamic requirement with adaptation and follow better appearance molding, can do such a layout arrangement, promptly: when the jaw protector 2 is in the position of the full helmet structure, the rotation axis O3 of the rotation surface structure of the transmission member 7 of at least one of the related mechanisms is in the position coincident with the internal gear axis O1 (see fig. 5, 6 and 31), and the sliding constraint pair of the related mechanism comprises a linear constraint element which is perpendicular to the plane formed by the internal gear axis O1 and the external gear axis O2 (see fig. 31), wherein the linear constraint element is based on the structure or the component of the internal gear 4 and the fork handle 2a which substantially participate in the constraint action, namely the linear constraint type sliding constraint pair comprises the structure and the components of the linear structure, wherein the structure and the component comprise but are not limited to grooves, rails, rods, edges, keys, shafts, holes, sleeves, columns, nails and the like; fig. 4 shows a linear constraint type sliding constraint pair formed by a straight-edge type first slide rail a matching with a straight-edge type second slide rail B, and corresponding to the linear constraint elements of the sliding constraint pair (i.e. the second slide rail B and the first slide rail a) when the jaw guard 2 is in the helmet structure position, which are perpendicular to the plane formed by the internal gear axis O1 and the external gear axis O2, while fig. 31(a) shows that the position and posture of the linear constraint type sliding constraint pair in the helmet structure position are arranged to be perpendicular to the plane formed by the internal gear axis O1 and the external gear axis O2, so that the arrangement not only can be beneficial to the design of the helmet, but also can enable the handle body of the fork handle 2a to better cover the through slot 6 on the internal gear 4 (see fig. 5 and 6), in order to more clearly see the influence process of the linear slide rail type sliding constraint pair on the overturning behavior of the jaw guard 2, fig. 31 shows a state relationship among the fork 2a, the through groove 6, and the transmission member 7 when the buckle cover of the fork 2a is hidden: wherein, fig. 31(a) shows that the jaw protector 2 is in the full helmet structure position, the second slide rail B and the first slide rail a of the linear constraint type sliding constraint pair are perpendicular to the plane formed by the internal gear axis O1 and the external gear axis O2, the rotation axis O3 of the transmission member 7 is coincident with the internal gear axis O1, the transmission member 7 is at the innermost end of the through groove 6 (the innermost end is also a moving limit point of the transmission member 7 relative to the through groove 6), fig. 31(B) shows that the jaw protector 2 is in the position state of being lifted and starting to climb, the second slide rail B and the first slide rail a of the linear constraint type sliding constraint pair synchronously rotate around the internal gear axis O1 following the internal gear 4, and the transmission member 7 slides to a middle position of the through groove 6, and fig. 31(c) shows that the jaw protector 2 is at the dome or its vicinity of the helmet shell body 1 (here, the state of the surface structure position is uncovered) At this time, the second slide rail B and the first slide rail a of the linear constraint type sliding constraint pair continue to rotate synchronously around the inner gear shaft O1 along with the inner gear 4, and at this time, the transmission member 7 slides to the outermost end of the through slot 6 (the outermost end is another movement limit point of the transmission member 7 relative to the through slot 6), fig. 31(d) calls that the jaw guard 2 is in a position state of falling back to the back of the helmet shell main body 1, at this time, the second slide rail B and the first slide rail a of the linear constraint type sliding constraint pair continue to rotate synchronously around the inner gear shaft O1 along with the inner gear 4, and at this time, the transmission member 7 slides back to a middle part of the through slot 6, and fig. 31(e) calls that the jaw guard 2 falls back to the back of the helmet shell main body 1, that is, to a state of reaching a semi-helmet structure position (note that in this state, the second slide rail B and the first slide rail a of the linear constraint type sliding constraint pair may be perpendicular or not perpendicular to the The plane formed by the line O1 and the external gear axis O2, and when the second slide track B and the first slide track a are perpendicular to the plane formed by the internal gear axis O1 and the external gear axis O2, then the axis of rotation O3 of the transmission element 7 will again coincide with the internal gear axis O1 and the transmission element 7 has returned to the innermost end of the through slot 6, in concert with the fact that the chin bar 2 has just turned 180 degrees relative to the helmet shell body 1 when it is flipped from the full helmet configuration position to the half helmet configuration position), it is not difficult to find that this design arrangement of the present invention will have at least two meanings and the benefits obtained therefrom: the first is to maximize the telescopic displacement of the chin bar 2 relative to the shell body 1, i.e. the maximum stroke of the chin bar 2, which is advantageous for improving the ability of the chin bar 2 to roll over, e.g. to climb over and cross the dome of the shell body 1 or over other accessories of the helmet, etc., the second is to maximize the degree of turning of the chin bar 2 relative to the shell body 1 and thus achieve a better appearance and aerodynamics of the helmet, since the pivot axis O3 of the transmission element 7 coincides with the internal gear axis O1 in the position of the helmet structure, such a layout makes it possible to raise the ring gear axis O1 of the ring gear 4 to the maximum in the dome direction closer to the helmet shell body 1, the space occupation of the inner gear 4 in the area below the human ear, which is of great importance for the design of the helmet and for the comfort of the wearer, can thus be significantly reduced.

The present invention is to ensure that the jaw guard 2 can effectively realize the switching from the full helmet structure position to the half helmet structure position, the central angle α covered by all the effective gears of the inner gear 4 can be greater than or equal to 180 degrees (see fig. 27), the main purpose of the arrangement is to ensure that the jaw guard 2 has a large enough turning range to meet the switching requirement between the full helmet structure and the half helmet structure, because the jaw guard 2 can achieve at least 180 degrees of maximum turning angle, and the half helmet structure corresponding to the jaw guard 2 position obtained at this time obviously has a good appearance and has good pneumatics, in addition, the present invention can also make the central angle α less than 360 degrees, i.e. the inner gear 4 is a gear not completely arranged all around, the advantage of the arrangement is that the inner gear 4 can vacate more positions to arrange other functional components, such as the inner gear, the locking mechanism, the elastic lifting mechanism, etc. can be used for arranging the gear teeth of the whole helmet structure outside the full helmet structure, even if the gear teeth 4 and the gear teeth are arranged completely arranged in the outer gear teeth 634 and the gear 4 has no special clamping mechanism, even if the gear teeth are arranged in the whole gear teeth occupying the whole gear teeth 634 and the outer gear teeth are arranged outside, the gear teeth are arranged completely occupied by the gear teeth 634, the gear teeth arranged outside the gear teeth arranged in the special clamping mechanism, the gear teeth are also arranged outside the gear teeth, the gear teeth are arranged outside the gear teeth, the gear teeth arranged outside the gear teeth arranged all the gear teeth are arranged in the gear teeth arranged all the gear teeth arranged outside the gear teeth arranged area, the gear teeth arranged in the gear teeth arranged outside the gear teeth of the gear teeth, the.

The utility model discloses a can let protect jaw 2 at full helmet structure position, half helmet structure position and even have certain stability on taking off a structure position, promptly protect jaw 2 can temporarily stop as required when above-mentioned position state, stagnate or stop, can be in collet 3 on or/and helmet shell main part 1 on set up a first screens structure 10a, be in simultaneously internal gear 4's body on or its extension body on set up at least one second screens structure 10b, and collet 3 on or/and helmet shell main part 1 on set up and can oppress and order about first screens structure 10a and paste and lean on the effect spring 11 (as shown in fig. 32) to second screens structure 10b, wherein first screens structure 10a and second screens structure 10b each other adopt the structure that stops of the matched stack of public mother's configuration, when first screens structure 10a and second screens structure 10b form mutually to stop when blocking and stop mutually supporting, they can produce the jamming and stop The remaining jaw guard 2 acts at the instant position and posture, and the acting force for clamping the posture of the jaw guard 2 at this time mainly comes from the compression force applied by the acting spring 11 and the friction force generated during clamping and matching (wherein the posture of the utility model refers to the sum of the two states of the position and the posture, which can describe the state of the position and the angle of the jaw guard 2); here, the second detent structure 10b can obviously rotate synchronously with the internal gear 4, when the second detent structure 10b is engaged with the first detent structure 10a, a weak locking effect can be formed on the chin guard 2, that is, the chin guard 2 can stay in a posture state of being weakly locked in a normal condition if no intervention is performed, at this time, the chin guard 2 is maintained at the instant position mainly by the acting force of the acting spring 11 (including the friction force preventing the chin guard 2 from shaking), and when the applied external force reaches a certain degree, the chin guard 2 can forcibly continue to perform the overturning motion by overcoming the engagement of the detent structure (at this time, the acting spring 11 performs the retreating motion to achieve the unlocking). From the viewpoint of simplified structure, the first detent structure 10a of the present invention can be designed to have a protruding tooth configuration, the second detent structure 10b of the present invention can be designed to have a recessed groove configuration (as shown in fig. 32), and the following configuration can be performed for the layout of the second detent structure 10 b: it should be noted that the second detent structure 10b of the present invention can be the tooth socket of the effective teeth of the internal gear 4, and the second detent structure 10b can directly use the tooth socket of the effective teeth of the internal gear 4 as its structure, or the second detent structure 10b can be the tooth socket of the effective teeth of the internal gear 4, and the second detent structure 10b can be the tooth socket of the effective teeth of the internal gear 4 As shown in fig. 32, the second detent structures 10b, which are engaged with the first detent structures 10a in response to the full-helmet structural position and the half-helmet structural position of the chin bar 2, are tooth grooves of the effective teeth of the inner gear 4. Still further, the present invention can be further provided with a second detent structure 10b (as shown in fig. 32 (b)) which engages with the first detent structure 10a when the jaw guard 2 is at or near the dome of the helmet shell body 1, so that the jaw guard 2 is additionally provided with an intermediate structure position between the full helmet structure and the half helmet structure, which corresponds to the jaw guard 2 being at or near the position of opening to the dome of the helmet, and which is also a so-called open jaw guard state (as shown in fig. 32 (b)) which is a state of use that is common at present, and which is advantageous for a driver to open the jaw guard 2 temporarily to perform various activities such as smoking, talking, drinking, resting, etc., the present invention can refer to the position of the jaw guard structure when the jaw guard 2 is at or near the dome of the helmet shell body 1 as an open jaw guard structure position, in other words, the present invention can have at least three states of jaw guard structure, namely: the helmet with the full-helmet structure, the helmet with the half-helmet structure and the helmet with the uncovering structure can further increase the humanity of the helmet. Furthermore, in order to further improve the user-friendly performance of the helmet, the utility model can also provide a lifting-assisting spring (not shown in the figure) on the base support 3 or/and the helmet shell main body 1, when the jaw protection 2 is in the full helmet structure position, the lifting-assisting spring is in the state of pressing and storing energy, and when the jaw protection 2 is overturned from the full helmet structure position to the uncovering structure position, the lifting-assisting spring is in the state of releasing the elastic force to assist the lifting of the jaw protection 2, and when the jaw protection 2 is in the state between the half helmet structure position and the uncovering structure position, the lifting-assisting spring does not generate acting force on the jaw protection 2 so as not to influence the overturning action of the jaw protection 2 in the period.

The utility model discloses such design arrangement can be carried out, namely: in the engagement constraint pair composed of the internal gear 4 and the external gear 5 of at least one related mechanism, besides the normal gear tooth engagement, the present invention can also alternatively arrange and set individual or a plurality of non-gear type engagement behaviors in the engagement motion process of the internal gear 4 and the external gear 5, that is, in some intervals, segments or processes of the normal gear tooth engagement of the internal gear 4 and the external gear 5, the engagement of non-gear type members with transitional properties is allowed to be alternatively arranged, for example, the engagement form (not shown in the figure) of non-gear type members such as column/groove type engagement, key/groove type engagement, etc. can be adopted, the present invention can be used for all the engagement types (arranged on the internal gear 4 or/and the external gear 5) and the engagement types substantially participate in the motion transmission between the internal gear 4 and the external gear 5, the engagement of the, The whole structure and elements (including convex structure and concave structure) of the meshing action of the power transmission, such as the effective gear teeth (including the special-shaped gear teeth 8a with larger tooth form, the special-shaped gear teeth 8b with wider tooth form and the correction gear teeth 8c with smaller tooth form, see fig. 30) of the normal configuration and the non-gear type meshing members of the auxiliary configuration, etc., are collectively called as the meshing elements, it is noted that the meshing of the non-gear type members is only auxiliary, and the guiding and restraining jaw guard 2 to make the telescopic displacement and the change of the attitude of the corner swing phase still mainly depend on the traditional gear type gear teeth to carry out the meshing restraint, therefore, the nature and the action of the gear restraining variable jaw guard structure of the present invention are not substantially changed, and at this time, it is assumed that the number of the meshing elements of the internal gear 4 obtained by the measurement and conversion according to 360 degrees for one whole circle is recorded, And the quantity number of the meshing component of external gear 5 who obtains according to 360 degrees whole circumference comes the measurement to be marked as external gear full-circumference equivalent number of teeth Zr, then the utility model discloses internal gear full-circumference equivalent number of teeth Zr and external gear full-circumference equivalent number of teeth Zr their ratio satisfies relational expression Zr/Zr ═ 2, see fig. 30: fig. 30(a) shows that the meshing elements of the internal gear 4 substantially engaged with each other are not circumferentially arranged by 360 degrees, fig. 30(b) shows that the equivalent number of teeth ZR of the internal gear 4 in the entire circumference is obtained by measuring (or converting) the entire circumference of 360 degrees, in fig. 30(b), the internal gear 4 may be denoted as the internal gear 4(ZR) and the external gear 5 may be denoted as the external gear 5(ZR) to represent that they are equivalent-converted gears, for example, if the total number of all the meshing elements of the external gear 5 actually engaged with each other is 14 and the 14 meshing elements are arranged by exactly not less than one entire circumference of 360 degrees, the equivalent number of teeth ZR in the entire circumference is equal to 14 external gears, and the number of the meshing elements of the internal gear 4 corresponding to this time theoretically only needs 14 to complete one-to-one mating engagement with the meshing elements of the external gear 5, obviously, the inner gear 4 with only 14 meshing elements cannot completely encircle a whole 360-degree circle, but according to the present invention, if the meshing elements of the inner gear 4 are arranged according to the principle that the ratio of the full-circle equivalent tooth number ZR of the inner gear to the full-circle equivalent tooth number ZR of the outer gear satisfies the relation ZR/ZR ═ 2, then the full-circle equivalent tooth number ZR of the inner gear will be equal to 28, so that the relative positions and the space occupation of the inner gear 4 and the outer gear 5 in the helmet shell main body 1 can be arranged according to the parameters that the full-circle equivalent tooth number ZR of the outer gear is equal to 14 and the full-circle equivalent tooth number ZR of the inner gear is equal to 28; it should be noted that, in practical applications, the present invention does not require that the internal gear 4 must necessarily design the number of meshing elements of the internal gear 4 according to the equivalent number of teeth ZR of the entire circumference of the internal gear, but only that the number of meshing elements in which the internal gear 4 substantially participates in meshing is not less than the number of meshing elements in which the external gear substantially participates in meshing. The purpose of the arrangement of the present invention is to keep the rotation speed of the internal gear 4 always at half of the rotation speed of the external gear 5, so as to ensure that the sliding constraint pair and the through groove 6 have a simple layout, such as a linear type configuration.

The utility model discloses such design arrangement can be carried out, namely: at least one of the related mechanisms has its external gear 5 provided with a web-shaped structural web 5a (as shown in fig. 4, 17 to 20), the web-shaped structural web 5a may be disposed on the tooth end surface of the external gear 5 or at any middle portion of the external gear 5 in the tooth thickness direction, preferably at a tooth space portion disposed on the tooth end surface, and the web-shaped structural web 5a may be disposed on all the teeth of the external gear 5 or on a part of the teeth of the external gear 5, preferably on all the teeth, and the web-shaped structural web 5a may be fabricated as an integral structure with the external gear 5 (as shown in fig. 4, 17 to 19) or may be a separate member (not shown) fastened to the external gear 5. The utility model discloses set up web-like structure web 5 a's purpose on external gear 5 is: on the one hand, the rigidity of the external gear wheel 5 can be increased by means of it, and on the other hand, a transmission element 7 can also be arranged on it.

The utility model discloses such design arrangement can be carried out, namely: at least one linking mechanism which is provided with a through groove 6 on the internal gear 4 and participates in the sliding constraint action of the internal gear 4 and the fork handle 2a, and the sliding constraint action is a part or all of the sliding constraint pair composed of the internal gear 4 and the fork handle 2a, the utility model has the advantages that the structural characteristics of the through groove 6 can be fully utilized to simplify the design of the helmet, in particular the structural design of the sliding constraint pair composed of the fork handle 2a and the internal gear of the jaw guard 2, in other words, two rail edges of the through groove 6 can also be used as the first sliding rail A of the sliding constraint pair (as shown in figures 4, 13 to 16), at this time, as long as the fork handle 2a is correspondingly provided with the second sliding rail B (as shown in figures 4, 24 and 25) which is matched with the first sliding rail A, the first sliding rail A can be matched with the second sliding rail B to jointly compose the sliding constraint pair (as shown in figure 26), therefore, the relative sliding motion between the internal gear 4 and the fork handle 2a can be restrained and realized, and the rotation torque between the internal gear 4 and the fork handle 2a can be transmitted (i.e. the turning motion of the fork handle 2a can be transmitted through the through groove 6 and the internal gear 4 is driven to turn synchronously, or vice versa the turning motion of the internal gear 4 can be transmitted through the through groove 6 and the fork handle 2a is driven to turn synchronously), it should be noted that the content of the "at least one association mechanism which is arranged on the through groove 6 of the internal gear 4 and participates in the sliding restraining action of the internal gear 4 and the fork handle 2a, and the sliding restraining action constitutes a part or all of the sliding restraining pair consisting of the internal gear 4 and the fork handle 2 a" includes two cases: 1) at least one through groove 6 of the linkage mechanism and the fork handle 2a form a unique sliding constraint pair between the internal gear 4 and the fork handle 2 a; 2) at least one through groove 6 and the fork handle 2a of the linkage mechanism are formed as one part of a sliding constraint pair formed by the internal gear 4 and the fork handle 2a, namely, the internal gear 4 and the fork handle 2a have other sliding constraint pairs besides the sliding constraint pair formed by the through groove 6 and the fork handle 2a, and all the sliding constraint pairs jointly participate in constraining the telescopic action and the overturning action between the internal gear 4 and the fork handle 2 a. Obviously, the utility model discloses making the aforesaid arrangement, on the one hand can enough practice thrift the space and realize compact design, and on the other hand can also improve the vice structural reliability of slip restraint and further improve the security of helmet.

The utility model discloses such design arrangement can be carried out, namely: the helmet may be provided with a shield 12, wherein the shield 12 is made of a transparent material, which functions to prevent the intrusion of sand wind and rain into the interior of the helmet, the shield 12 comprises two legs 13 (see fig. 33 and 34), the two legs 13 are disposed on two sides of the helmet shell body 1 and can swing around the shield axis O4 with respect to the helmet shell body 1, that is, the shield 12 can be buckled to prevent wind, sand and rain, the shield 12 can be opened to facilitate the activities of drinking and talking of the wearer, at least one leg 13 of the two legs 13 of the shield 12 is provided with a force bearing rail edge 14 (as shown in figures 33 to 36), the supporting legs 13 provided with the bearing rail edges 14 are arranged between the bottom support 3 and the helmet shell main body 1; a through opening 15 (shown in fig. 4, 7-9) is arranged on the inner supporting plate 3a of the bottom support 3 facing the helmet shell main body 1, and a trigger pin 16 (shown in fig. 4, 17, 18, 20, 33-36) which extends out of the opening 15 and can touch the force bearing rail edge 14 of the supporting leg 13 is arranged on the outer gear 5; when the protective cover 12 is in a complete buckling and closing state, the arrangement of the trigger pin 16 and the bearing rail edge 14 meets the following conditions: if the protective jaw 2 starts from the complete full helmet structure position to perform the opening action, the trigger pin 16 must be able to touch the bearing rail edge 14 on the supporting leg 13 of the protective shield 12 and thereby drive the protective shield 12 to perform the opening action, if the protective jaw 2 starts from the half helmet structure position to perform the returning action towards the full helmet structure position, the trigger pin 16 must be able to touch the bearing rail edge 14 on the supporting leg 13 of the protective shield 12 and thereby drive the protective shield 12 to perform the opening action during the first two thirds of the whole returning course of the protective jaw 2, wherein, if the protective jaw 2 starts from the complete full helmet structure position to perform the opening action, the trigger pin 16 must be able to touch the bearing rail edge 14 on the supporting leg 13 of the protective shield 12 and thereby drive the protective shield 12 to perform the opening action once the protective jaw 2 is not required to start, the trigger pin 16 must be able to touch the bearing rail edge 14 to drive the supporting leg 13 to drive the protective shield 12 to perform the opening action once the protective jaw 2 is started The opening action is immediately performed by the protective cover 12, but the protective cover 2 can be started with a certain delay at the moment, which includes the delay requirement in the aspect of functional design, the delay requirement caused by the elastic deformation of relevant parts, the clearance elimination process and the like, of course, the utility model also includes the situation that the protective cover 12 immediately generates the opening action by the trigger pin 16 immediately touching the bearing rail edge 14 of the supporting leg 13 once the jaw protector 2 is started; fig. 33 shows the linkage process of the internal gear 4, the external gear 5, the trigger pin 16, the shield 12 and the support legs 13 thereof (here, the jaw guard 2 performs the original turning action) in the process that the jaw guard 2 is opened from the full helmet structure position to the half helmet structure position: wherein, figure 33(a) calls for the jaw guard 2 to be in a full helmet configuration position and in a ready-to-roll state in which the shield 12 is being fully snapped down, figure 33(b) calls for the jaw guard 2 to begin to roll → the inner gear 4 to rotate → the outer gear 5 to be driven to rotate by the inner gear 4 → the trigger pin 16 to rotate synchronously with the outer gear 5 → the trigger pin 16 to contact and drive the force-bearing rail edge 14 on the leg 13 → the leg 13 to begin to produce a fixed axis swinging motion about the shield axis O4 → the shield 12 to begin to lift open and climb, figure 33(c) calls for the jaw guard 2 to continue to roll and reach near the dome of the helmet shell body 1 → 4 to continue to rotate and continue to rotate the trigger pin 16 by the inner gear 5 → the trigger pin 16 to push the force-bearing rail edge 14 and continue to drive the shield 12 to swing upwardly by it and reach its maximum lift limit → figure 33(d) calls for the jaw 2 to continue to roll and reach the inner gear 4 at the rear spoon of the helmet shell body 1 The trigger pin 16 continues to rotate through the external gear 5 but the shield 12 reaches and stays at the highest lift and the trigger pin 16 also disengages from the force-bearing rail edge 14 of the leg 13 → fig. 33(e) corresponds to the trigger pin 16 being driven by the internal gear 4 and the external gear 5 to move further away from the force-bearing rail edge 14 of the leg 13 when the chin guard 2 has reached the half-helmet structure position; fig. 34 shows the linkage process of the inner gear 4, the outer gear 5, the trigger pin 16, the shield 12 and the support leg 13 during the process of returning the shield 2 from the half-helmet structure position to the full-helmet structure position: wherein, fig. 34(a) corresponds to the position of the jaw guard 2 in the half helmet structure and in the state to be overturned, in which the shield 12 is in the completely buckled state, fig. 34(b) corresponds to the state in which the jaw guard 2 starts to return and overturns → the inner gear 4 rotates → the outer gear 5 is driven by the inner gear 4 rotates → the trigger pin 16 follows the outer gear 5 to rotate synchronously → but the trigger pin 16 does not contact the force-bearing rail edge 14 on the driving leg 13 yet, so that the shield 12 remains in the completely buckled state, fig. 34(c) corresponds to the state in which the jaw guard 2 continues to return and overturns and reaches the vicinity of the dome of the helmet body 1 → the trigger pin 16 has rotated to the position in which the force-bearing rail edge 14 is reached by the driving of the inner gear 4 and the outer gear 5 → the driving leg 13 generates the action of opening the shield by the driving pin 16 → 12 generates the fixed axis swinging motion about the shield axis O4 and disengages from the completely buckled position → the shield 12, and the return course of the jaw guard 2 completed during this period Two thirds of the full return stroke has not yet expired, figure 34(d) corresponds to the jaw guard 2 continuing to return → the inner gear 4 continuing to rotate and continue to rotate through the outer gear 5 so that the trigger pin 16 continues to rotate → the trigger pin 16 pushes the weighted rail edge 14 and continues to drive the shield 12 through it to swing up and reach its maximum lift limit → figure 34(e) corresponds to the jaw guard 2 having returned to the full helmet configuration position and the inner gear 4 continuing to rotate and carrying the trigger pin 16 through the outer gear 5 but at this time the shield 12 has reached and stayed at the maximum lift and the trigger pin 16 has also disengaged from the weighted rail edge 14 of the leg 13. It should be pointed out that, in each landing leg 13 of the present invention, its bearing rail edge 14 only needs to be set up one to accomplish the corresponding function, and therefore compared with the prior art CN107432520A the present invention can greatly simplify the mechanism design of the driving protecting cover 12, on the one hand, the design of the landing leg 13 can be simplified and the structure becomes more reasonable, which can be clearly seen from the embodiment given in fig. 36 of fig. 33 (it can be seen from the figure that the landing leg 13 of the present invention, whether it is thickness or structural layout, is obviously improved in the stress direction, and its rigidity and strength are obviously enhanced), on the other hand, the layout of the trigger pin 16 of the driving landing leg 13 is more reasonable, firstly, the track range of its operation can be limited to a smaller range, this creates the condition for compact design, secondly, the stress point of its triggering landing leg 13 bearing rail edge 14 is more far away from the protecting cover axis O4 of the protecting cover 12 and is closer to the application of the locking mechanism of the protecting cover 12 The force points and thus the forces between the trigger pin 16 and the carrier rail edge 14 can be significantly reduced, which is clearly of great benefit for increasing their reliability. The utility model discloses make the purpose of above-mentioned design arrangement and prevent that jaw guard 2 from being when doing the upset action, can avoid appearing jaw guard 2 effectively by the dead phenomenon of guard shield 12 card or guard shield 12 is bumped by jaw guard 2 to improve security and the reliability that the helmet used.

The utility model discloses such design arrangement can be carried out, namely: a first lock tooth 17 is provided on the leg 13 of the shield 12, a second lock tooth 18 corresponding to the first lock tooth 17 is provided on the base plate 3 or/and the helmet main body 1, and a lock spring 19 is provided on the base plate 3 or/and the helmet main body 1 (as shown in fig. 35 and 36), the first lock tooth 17 moves synchronously with the shield 12, the second lock tooth 18 can move or swing relative to the helmet main body 1, the second lock tooth 18 can abut against the first lock tooth 17 under the action of the lock spring 19 when the shield 12 is in the locked state, so that the shield 12 obtains a weak lock effect (see fig. 35(a) and 36(a)), when the shield 12 is forced to open, the first lock tooth 17 can drive the second lock tooth 18 to urge the second lock tooth 18 to press the lock spring 19, At the same time, the second locking tooth 18 displaces and makes the second locking tooth 18 perform a yielding unlocking action on the first locking tooth 17 (see fig. 35(b) and fig. 36(b)), wherein fig. 35 describes a process of unlocking the shield 12 whose initial position is in the completely buckled position by the chin guard 2 moving from the full helmet structure position to the half helmet structure position, and fig. 36 describes a process of unlocking the shield 12 whose initial position is in the completely buckled position by the chin guard 2 moving from the half helmet structure position to the full helmet structure position, and it should be noted that the locking structures of the first locking tooth 17 and the second locking tooth 18 may be only one pair of locking structures or two or more pairs of locking structures, and the "unlocking action" in the present invention means that the second locking tooth 18 performs a yielding action on the first locking tooth 17 under the driving pressure generated by the rotation of the first locking tooth 17 The event of rotation, in particular, includes unlocking the shield 12 in the fully latched position. In fig. 35: fig. 35(a) corresponds to the jaw protector 2 in the position of the full helmet structure, and the second catching teeth 18 are locked with the first catching teeth 17 of the legs 13 of the shield 12, so that the shield 12 is locked in the fully buckled state to protect the wearer from external sand, rain, etc.; fig. 35(b) corresponds to the jaw guard 2 being in the state of turning from the position of the helmet structure and having made some slight opening motion → at this time the jaw guard 2 drives the inner gear 4 → the inner gear 4 drives the outer gear 5 → the outer gear 5 drives the trigger pin 16 → the trigger pin 16 drives the force-bearing rail edge 14 on the leg 13 → the leg 13 makes a fixed axis swinging motion around the shield axis O4 → the first locking tooth 17 rotates and presses the second locking tooth 18 to make unlocking abduction → the second locking tooth 18 gets unlocked so that the shield 12 starts to get out of the fully buckled position and is in a slightly opened state which is advantageous for ventilation and disperses the mist in the helmet by the fresh air outside, it should be noted that, fig. 35(b) shows the second locking tooth 18 having completed the first unlocking action of the first locking tooth 17, i.e., driving the shield 12 out of the fully latched position, and entering the second locked position, i.e., arresting the shield 12 in the ajar position; fig. 35(c) and 35(d) correspond to the chin bar 2 continuing to advance towards the half-helmet configuration position, and the shield 2 is driven by the trigger pin 16 to a position where it is more open, but where the first and second lock teeth 17, 18 have been fully disengaged. In fig. 36: figure 36(a) corresponds to the jaw guard 2 in the position of the helmet half configuration and the second capturing tooth 18 is now locked with the first capturing tooth 17 on the leg 13 of the shield 12 so that the shield 12 is locked in a fully latched position protecting the wearer from external sand, rain, etc.; figure 36(b) corresponds to the jaw guard 2 in the position starting from the position of the helmet half structure and starting to turn back again and during the first two thirds of the travel of the whole return stroke, the trigger pin 16 touches and drives the shield to generate a certain fixed axis swinging motion → the first locking tooth 17 rotates and presses the second locking tooth 18 to perform unlocking yielding → the second locking tooth 18 obtains unlocking so that the shield 12 starts to leave the fully buckled position and is in a slightly opened state; fig. 36(c) and 36(d) correspond to the jaw guard 2 continuing to return to the fully assembled position, the shield 2 being driven by the trigger pin 16 to a more open position, but with the first and second locking

teeth

17, 18 fully disengaged. The weak locking means that the shield 12 can stay at the locking position (i.e. the locked state) if the shield 12 is not intentionally driven, and the shield 12 can still be unlocked to open when the helmet wearer forcibly pulls the shield 12 with his hand or forcibly drives the jaw guard 2 so that the trigger pin 16 on the external gear 5 forcibly drives the force-bearing rail edge 14 on the leg 13 of the shield 12.

Compared with the prior art, the utility model has the outstanding advantages that the layout form of the association mechanism is composed of the jaw guard 2, the inner gear 4, the outer gear 5 and the transmission part 7, the inner gear 4 and the outer gear 5 are enabled to rotate around the fixed axis and are meshed with each other to form a motion constraint pair, meanwhile, the inner gear 4 is provided with the constraint pair in sliding fit with the jaw guard 2 fork 2a, the inner gear 4 and the outer gear 5 can be mutually driven to generate rotary motion, the fork is driven to generate reciprocating displacement relative to the inner gear 4 by the transmission part 7 matched with the constraint relation with the outer gear 5 and the jaw guard 2 fork 2a, thereby the position and the posture of the jaw guard 2 can be exactly changed along with the opening or closing motion of the jaw guard 2, and finally, the jaw guard 2 is converted between the full-helmet structure position and the half-helmet structure position, and the uniqueness and reversibility of the running geometric locus of the jaw guard 2 can be kept. Based on the layout form and the operation mode of the association mechanism, the utility model discloses in the process of changing the position of the jaw guard 2, can make the handle body of the jaw guard 2 fork handle 2a synchronously follow the internal gear 4 to make a rotary motion together, thereby can basically or even completely cover the through groove 6 on the internal gear 4, so both can avoid external foreign matters to enter the restraint pair and guarantee the reliability of helmet use, can also block the route that external noise invades the helmet inside and improve the comfort of helmet use; meanwhile, the external gear 5 rotating around the fixed shaft occupies less operating space, so that more flexible layout selection is provided for the fastening structure of the bottom support 3, and the supporting rigidity of the bottom support 3 can be improved, thereby improving the overall safety of the helmet.

The above-mentioned embodiments are only a plurality of preferred embodiments of the present invention, and do not limit the protection scope of the present invention according to this, so: all the equivalent changes made according to the structure, shape and principle of the utility model are covered within the protection scope of the utility model.

Claims

1. A gear-constrained helmet with a variable jaw protection structure comprises a helmet shell main body, a jaw protection and two bottom supports, wherein the two bottom supports are respectively arranged on two side surfaces of the helmet shell main body and are fastened on the helmet shell main body or are manufactured with the helmet shell main body in an integrated structure; the method is characterized in that: the helmet shell comprises a helmet shell body, a base, a pair of inner gears and an outer gear, wherein the helmet shell body is provided with a helmet shell body, the helmet shell body is provided with a pair of through holes, the inner gears are correspondingly provided with inner gears and outer gears, the inner gears are restrained by the base or/and the helmet shell body, the outer gears are restrained by the base or/and the helmet shell body, the inner gears rotate around the axes of the inner gears and the outer gears rotate around the axes of the outer gears, a through groove is formed in the body of the inner gears or an attachment piece of the inner gears, a transmission piece penetrating through the through grooves is additionally arranged, and the base; in the same associated mechanism, the fork handle is arranged outside the through groove on the inner gear, the outer gear and the inner gear are meshed with each other and form a motion constraint pair, the inner gear and the fork handle are mutually matched in a sliding manner and form a sliding constraint pair, one end of the transmission piece has a matching constraint relation with the outer gear, the transmission piece can receive the drive of the outer gear or the external gear can receive the drive of the transmission piece through the constraint relation, and the other end of the transmission piece has a matching constraint relation with the fork handle and enables the fork handle to receive the drive of the transmission piece or the transmission piece can receive the drive of the fork handle through the constraint relation.

2. A gear-restraining variable jaw structure helmet as claimed in claim 1 wherein: in the same associated mechanism, the motion constraint pair formed by the inner gear and the outer gear belongs to the category of a plane gear transmission mechanism.

3. A gear-restraining variable jaw structure helmet as claimed in claim 2 wherein: in the same related mechanism, the internal gear and the external gear are cylindrical gear types, and when the internal gear and the external gear are meshed with each other, an internal gear pitch circle radius R formed on the internal gear and an external gear pitch circle radius R formed on the external gear satisfy the relation R/R ═ 2.

4. A gear-restraining variable jaw structure helmet as claimed in claim 3 wherein: in the same connection, the transmission element comprises a surface of revolution arrangement comprising a revolution axis which always follows the external gear synchronously with a fixed axis rotation about the axis of the external gear, said revolution axis being arranged parallel to the axis of the external gear and intersecting the pitch circle of the external gear.

5. A gear-restraining variable jaw structure helmet as claimed in claim 4 wherein: the revolution surface of the transmission part is in a cylindrical surface structure form or a conical surface structure form.

6. A gear-restraining variable jaw structure helmet as claimed in claim 5 wherein: the matching and constraint relation between the transmission piece and the external gear is that the transmission piece and the external gear are connected in a fastening way or are manufactured as an integral structure, and the matching and constraint relation between the transmission piece and the fork handle is that the transmission piece and the external gear are in rotating fit; or the matching constraint relation between the transmission piece and the external gear is the relation that the transmission piece and the external gear are in rotating fit, and the matching constraint relation between the transmission piece and the fork handle is the relation that the transmission piece and the fork handle are in fastening connection or are manufactured as an integrated structure; further alternatively, the coupling constraint relationship between the transmission member and the external gear is a rotational fit relationship, and the coupling constraint relationship between the transmission member and the fork is a rotational fit relationship.

7. A gear-restraining variable jaw structure helmet as claimed in claim 6 wherein: the inner gear, the bottom support or/and the helmet shell body are/is provided with a second anti-slip component which can prevent the outer gear from axially shifting, and the inner gear is provided with a third anti-slip component which can prevent the jaw protection fork from axially loosening.

8. A gear-restraining variable jaw structure helmet as claimed in claim 7 wherein: at least one gear tooth in each gear tooth of the external gear is designed into a special-shaped gear tooth with the tooth thickness larger than the average tooth thickness of all effective gear teeth on the external gear, and the transmission piece is in matching constraint relation with and only with the special-shaped gear tooth.

9. A gear-restraining variable jaw structure helmet as claimed in claim 8 wherein: the through grooves on the internal gear are flat straight groove type through grooves, the straight groove type through grooves are distributed to point to or pass through the axis of the internal gear, the sliding constraint pair formed by the mutual sliding fit of the internal gear and the fork handle is a linear constraint type sliding constraint pair, the linear constraint type sliding constraint pair is distributed to point to or pass through the axis of the internal gear, and meanwhile the straight groove type through grooves and the linear constraint type sliding constraint pair are arranged in a mutual superposition mode or in a mutual parallel mode.

10. A gear-restraining variable jaw structure helmet as claimed in claim 9 wherein: when the corresponding jaw is in the position of the full helmet structure, the rotation axis of the rotation surface structure of the transmission part of at least one of the related mechanisms is in the position coincident with the axis of the internal gear, and the linear constraint element contained in the sliding constraint pair of the related mechanism is vertical to the plane formed by the axis of the internal gear and the axis of the external gear.

11. The gear-constrained variable jaw guard helmet as claimed in claim 10, wherein the internal gear has a central angle α greater than or equal to 180 ° for all active gears.

12. A gear-restraining variable jaw structure helmet as claimed in claim 11 wherein: the collet on or/and the helmet shell main part on be provided with first screens structure, be in simultaneously the body of internal gear on or its extension body on seted up at least one second screens structure, and the collet on or/and the helmet shell main part on still be provided with the oppression and order about first screens structure and paste and lean on the effect spring to second screens structure, first screens structure and second screens structure adopt each other to be the structure that stops of public female configuration matched stack, when first screens structure and second screens structure form to stop mutually that they can produce the jamming and stop the effect of position and gesture when protecting the jaw.

13. A gear-restraining variable jaw structure helmet as claimed in claim 12 wherein: the first clamping structure is in a convex tooth configuration, the second clamping structure is in a groove configuration, and the second clamping structure is configured as follows in layout: the calling jaw protector is provided with a second clamping structure which is clamped with the first clamping structure when in the position of the full helmet structure, and the calling jaw protector is also provided with a second clamping structure which is clamped with the first clamping structure when in the position of the half helmet structure.

14. A gear-restraining variable jaw structure helmet as claimed in claim 13 wherein: when the jaw is in the uncovering structure, a second clamping structure which is clamped with the first clamping structure is also arranged.

15. A gear-restraining variable jaw structure helmet as claimed in claim 14 wherein: the lifting-assisting spring is arranged on the bottom support or/and the helmet shell main body, when the jaw protection is in the full helmet structure position, the lifting-assisting spring is in a state of pressing energy storage, when the jaw protection is overturned from the full helmet structure position to the dome of the helmet shell main body, the lifting-assisting spring is in a state of releasing elasticity to assist in pushing the jaw protection to be opened, and when the jaw protection is in a state between the half helmet structure position and the uncovering structure position, the lifting-assisting spring can stop generating acting force on the jaw protection.

16. A gear-restraining variable jaw guard helmet according to any one of claims 1 to 15 characterised in that: at least one of the association mechanism's internal gear full-circumference equivalent tooth number ZR of the meshing element included in the internal gear and external gear full-circumference equivalent tooth number Zr of the meshing element included in the external gear satisfy the relation ZR/Zr ═ 2.

17. A gear-restraining variable jaw guard helmet according to any one of claims 1 to 15 characterised in that: at least one of the associated mechanisms has a web-like structure on its outer gear.

18. A gear-restraining variable jaw guard helmet according to any one of claims 1 to 15 characterised in that: at least one correlation mechanism is arranged on the through groove of the internal gear, participates in the sliding constraint action of the internal gear and the fork handle, and the sliding constraint action is formed as a part or the whole of a sliding constraint pair formed by the internal gear and the fork handle.

19. A gear-restraining variable jaw guard helmet according to any one of claims 1 to 15 characterised in that: the helmet is provided with a protective cover which comprises two support legs, the two support legs are respectively arranged on two side surfaces of the helmet shell main body and can do fixed-axis swinging motion relative to the helmet shell main body, at least one support leg is provided with a bearing rail edge, and the support leg provided with the bearing rail edge is arranged between the bottom support and the helmet shell main body; a through opening is arranged on the inner supporting plate of the bottom support facing the helmet shell main body, and a trigger pin which extends out of the opening and can touch the supporting leg force bearing rail edge is arranged on the outer gear; when the protective cover is in a complete buckling and closing state, the layout of the trigger pin and the bearing rail side meets the following conditions: if the jaw guard starts from the complete full helmet structure position and performs the opening action, the trigger pin must be capable of touching the force bearing rail edge on the protective cover supporting leg and driving the protective cover to generate the turning and opening action, and if the jaw guard starts from the complete half helmet structure position and returns to the full helmet structure position, the trigger pin must be capable of touching the force bearing rail edge on the protective cover supporting leg during the first two thirds returning period of the whole returning period of the jaw guard and driving the protective cover to generate the turning and opening action.

20. A gear-constrained variable jaw structure helmet according to claim 19 wherein: the protective cover is characterized in that a first lock tooth in a tooth shape is arranged on a supporting leg of the protective cover, a second lock tooth corresponding to the first lock tooth is arranged on the bottom support or/and the helmet shell main body, a lock spring is arranged on the bottom support or/and the helmet shell main body, the first lock tooth synchronously moves along with the protective cover, the second lock tooth can move or swing relative to the helmet shell main body, when the protective cover is in a buckled state, the second lock tooth can be attached to the first lock tooth under the action of the lock spring so that the protective cover obtains a weak locking effect, and when the protective cover is driven by external force to open, the first lock tooth can forcibly drive the second lock tooth to press the lock spring to generate displacement and accordingly perform yielding unlocking action on the first lock tooth.