EP0838172A2

EP0838172A2 - Quick-release buckle for straps of helmets for motorcyclists, cyclists and similar uses

Info

Publication number: EP0838172A2
Application number: EP97116789A
Authority: EP
Inventors: Paolo Collini
Original assignee: Collini Demetrio SpA
Current assignee: Collini Demetrio SpA
Priority date: 1996-10-02
Filing date: 1997-09-26
Publication date: 1998-04-29
Also published as: EP0838172A3

Abstract

Quick-release buckle for straps of helmets for motorcyclists and the like, particularly for chin-straps, of the type comprising: a containment body; a metal plate (1) with an eyelet (1a) for coupling to a strap portion which is rigidly coupled to the helmet and with edges folded in the shape of the letter U; a bayonet (8) having, at one end, an eyelet and, at the opposite end, a slot (8b) for engaging a raised portion which protrudes from the plate (1); and a button (4), which is arranged in opposition to return springs (6); the buckle is constituted by a metal plate (1), with an eyelet (1a) which is rigidly coupled to the strap portion and with edges which are folded in the shape of the letter C and constitute two sliding guides (1b; 1c) for the release button (4) arranged in opposition to a return spring (6). The plate (1) is enclosed between a box-like body (2) and a lower cover (3) which is open at the front and is provided with engagement means, constituted by a substantially arc-shaped raised portion (10) or by a through hole (14), which are arranged close to the fixed eyelet (1a) and are shaped so as to allow their stable coupling in corresponding arc-shaped means (8b; 13) formed at the end of a flat bayonet (8) after the insertion of the bayonet in the buckle body. The insertion of the bayonet (8) causes the movement of the button (4) and the loading of the spring (6) until the mutual engagement of the coupling means (8b; 10; 13, 14) is completed; the coupling is stabilized by the automatic return of the button (4) above the mutually coupled means, while release is achieved by simply retracting the button.

Description

The present invention relates to a quick-release buckle for full-face and open-front helmets for motorcyclists, cyclists and for similar uses, particular but not exclusively suitable to be arranged halfway along the chin- strap.

Various buckles for open-front and full-face helmets for cyclists, motorcyclists and for safety belts in general are currently in use whose structure, operation, safety and ease against accidental release vary according to the use and to the standards that prescribe their characteristics and degrees of safety.

Many of these conventional buckles also have, according to their uses, internal structures which are not always easy to couple and release or which create discomfort when the buckles are placed in contact with the face or with the throat of the helmet wearer.

In general, current buckles for helmets for motorcyclists and the like are manufactured in the form of a flattened prism-shaped body and can be actuated by means of a single release button or by means of two opposite buttons which can be operated simultaneously.

The internal structure of these buckles is usually constituted by elements which allow the coupling and release of a flat tongue with an eyelet-shaped head, which bears the strap to be coupled to the buckle and is often termed "bayonet" because it can be inserted with a snap-together action in a slot formed in the box-like body that encloses the coupling and release mechanism. In some cases, the eyelet-shaped head of the bayonet is locked inside the body of many helmet buckles by coupling the eyelet of the head with a hook or lug which protrudes from the base of the box-like body and by retaining it by means of elements which can shift in contrast with preloaded springs, whose function is to keep the coupling stable and allow, by means of the translatory motion of a button, said fixed hook to exit from the eyelet of the bayonet head and said bayonet to be simultaneously expelled from the body of the buckle.

Although these conventional buckles generally meet the legal standards as regards coupling stability and pulling strength, in practice they are mainly suitable to be arranged laterally to the helmet user's face; if they are instead placed halfway along the chin-strap, said buckles entail significant drawbacks, especially difficulties in release.

For buckles to be applied under the chin, the most recent standards (ECE 22:04 standards) in fact require a very specific opening force (no more than 3 kg), require said buckles to be applied under the chin, and subject the test head and helmet to intense pulling; according to these standards, the test head has a substantially square jaw, so that the straps of the buckle are subjected to traction in an almost horizontal direction; accordingly, the high traction force requires in practice a considerable effort in order to shift the opening button, and for these same reasons the slot of the bayonet tends to be retained on the end of the fixed hook even when the button is shifted into the opening position.

In order to attempt to obviate these drawbacks and therefore to comply with the most recent standards, chin-strap buckles have been provided which have an inclined bayonet, which in practice reduces the opening forces; the inclination of the bayonet is provided by forming a raised portion between the internal plane of the buckle body and the surface that faces said bayonet. This raised portion allows the bayonet to behave during opening, i.e., while it is being pulled, like a lever whose fulcrum lies on said fixed raised portion, so that by partially rotating it releases the slot of said bayonet from the locking raised portion.

In practice, it has been observed that the insertion of said raised portion in the buckle does not always ensure correct release of the bayonet from the fixed coupling raised portion, even if a leaf spring, capable of acting during opening on the internal end of said bayonet in order to facilitate release from the raised portion, cooperates with said bayonet.

It has also been noted that all current buckles for both open-front and full-face helmets can entail severe drawbacks, especially when they are used approximately in the middle region of chin-straps.

In these applications, current buckles in fact allow correct release of the bayonet only if the buckle is arranged on the central part of the chin and the two strap portions are correctly tensioned. Otherwise, release of the bayonet can be very difficult because of the different degree of tension of the two strap portions; likewise, current buckles are almost always too bulky for smaller-than-average chins and can entail difficulties in operating the release button, especially when the user is wearing gloves, which of course produce a significant bulk around the finger of the hand that must operate the release button.

Moreover, current buckles for chin use, owing to their significant constructive complexity and to their bulk, entail in practice costs and production times which can be rather high.

Accordingly, the aim of the present invention is to provide a buckle for use in the middle region of chin-straps in particular and for other uses in general, designed and structured so as to completely obviate the drawbacks and limitations of the various buckles for helmets and the like, such that it fully complies with the prescriptions of the most recent Standards concerning chin-strap buckles, and most of all allows quick and safe release for opening without requiring efforts beyond prescribed values.

Within the scope of this aim, an object of the present invention is to provide a buckle of the above type which is structured so as to be very compact and therefore lighter than current chin-strap buckles, with evident practical and economical advantages.

Another object of the present invention is to provide a buckle which is structurally simple and highly reliable and allows bayonet release in any operating condition, including use in chin-straps for people with chins smaller than those normally present in adults.

Another object of the present invention is to allow safe release of the bayonet also by users wearing gloves on their hands.

This aim, these objects and others which will become apparent hereinafter are achieved by a quick-release buckle, particularly suitable for arrangements halfway along a chin-strap of helmets for motorcyclists, cyclists and the like and for other uses, of the type comprising: a box-like containment body; a metal plate with longitudinal edges folded in the shape of the letter U and provided at one end with an eyelet for coupling to a strap portion which is rigidly coupled to the helmet; a bayonet having, at one end, an eyelet for coupling to the other strap portion and, at the opposite end, a slot which is suitable to engage a fixed raised portion which protrudes from said metal plate; and a button, which is arranged in opposition to return springs and can shift within said box-like body in order to actuate means suitable to allow the release of the bayonet from said raised portion; said quick-release buckle being constituted, according to the present invention, by a metal plate with an eyelet for fixed coupling to the strap and with longitudinal edges which are folded inwardly substantially in the shape of the letter C, so as to constitute two sliding and retention guides for a release button arranged in opposition to at least one return spring, said metal plate being enclosed between an upper flat box-like body which is open at one end and a lower closure cover, bayonet coupling means being further provided on said metal plate, said means being constituted by a raised portion or protrusion which has a curved surface or by a hole or similar cavity, arranged close to the fixed eyelet of said plate, said coupling means being shaped so as to allow their stable coupling within corresponding complementarily shaped means which are associated with, or formed at, the end of a flat bayonet which is suitably elongated and inserted in the body of the buckle; the dimensions and position of said coupling means rigidly coupled to said metal plate and of said corresponding engagement means rigidly coupled to said bayonet being such as to allow the button, at the end of the insertion of the bayonet in the body of the buckle with simultaneous retraction of the button and loading of the spring, to maintain the stable locking of the bayonet on the plate by means of its automatic return above and beyond said engagement means, the release of the bayonet being achieved by retracting the button into the buckle body.

More particularly, said raised portion or protrusion having a curved surface is constituted by a half-cylinder which is formed in said metal plate or applied thereto so that its axis is arranged transversely to said plate and has, on the side directed toward the inlet of the bayonet, a blending portion which is shaped like an inclined plane and is suitable to facilitate the entry of a slot formed in the bayonet during coupling thereof.

Moreover, said hole formed in said metal plate is provided with a substantially circular or rectangular shape and has dimensions chosen so as to accommodate and stably retain inside it a dome or protrusion which is substantially hemispherical or semicylindrical and is rigidly coupled to the lower face of the end of said flat bayonet.

Moreover, said button has, on its two longitudinal sides, portions of tabs which protrude from the button body and are suitable to form, together with two underlying straight protrusions which protrude from the button body, two U-shaped parallel guides which are meant to internally accommodate the upper horizontal edge of said wings that protrude from the metal plate and thus allow the button to slide in both directions without vertical and lateral swaying or excessive friction between the parts in mutual contact.

Likewise, said button return spring is inserted with one end in a hole formed centrally in the button body and, with its opposite end, in a protrusion formed correspondingly in the vertical rear inner part of said upper box-like body.

Further characteristics and advantages of the present invention will become apparent from the following detailed description, given with reference to the accompanying drawings, which are provided merely by way of non-limitative example and wherein:

figure 1 is an exploded perspective view of all the components of the quick-release buckle according to the present invention;

figure 2 is a longitudinal median sectional view of the assembled buckle, showing the bayonet during the insertion step;

figure 2a is a sectional view, taken along the plane A-A;

figure 3 is a view of the same buckle of figure 2 with the bayonet in locking position inside said buckle;

figure 4 is a longitudinal median sectional view of a second embodiment of the buckle according to the invention, shown in the assembled condition and with bayonet insertion in progress;

figure 5 is the same sectional view of figure 4, but with the bayonet in locking position; and

figures 6, 7 and 8 are full and sectional views of details of figures 4 and 5.

With reference to the above figures and particularly to figures 1 to 3, the buckle according to the present invention is constituted, according to a first embodiment, by the assembly of a metal plate 1 having, at one end, an expansion which includes a conventional slot or eyelet 1a which is meant to be stably connected in a conventional manner to the end of a strap portion which is rigidly coupled to a helmet (not shown). Said plate has two opposite wings 1b which are folded upwardly and then inwardly, so as to form two flaps 1c which are parallel to the base plate 1; said flaps 1c are meant to constitute two planes or guides for the sliding of an actuation button, as will become apparent hereinafter.

Said metal plate 1 is furthermore enclosed within a flat box-like body 2 which is open at the front, as shown by 2a, and then stably closed in a downward region by a cover 3 by conventional means, such as gluing, ultrasound welding or the like.

The buckle also comprises an actuation button, generally designated by the reference numeral 4, which has a raised portion 4a for actuation, a central flat body 4b and two lateral flaps 4c which protrude outward and are meant to slide on the upper face 1c of the folded wings 1b of the metal plate 1; the central body 4b of the button 4 also has two identical blocks 4d, above which there are provided two opposite and identical steps 4e which are parallel to the upper flaps 1c and are meant to slide on the underlying face of the flaps 1c of the plate 1, as shown in cross-section in figure 2a. A cylindrical blind hole 5 is formed between said two blocks 4d of the button and loosely accommodates one end of a cylindrical spiral spring 6; said blocks 4d have a depressed region which is suitable to form a front step 7 (figures 2-3), against which the end of a flat bayonet 8, which is of a known kind but is flat and elongated, is meant to strike and push, loading the spring 6 against the bottom of the hollow body 2, where the opposite end of said spring 6 is inserted in a suitable seat 9.

The buckle also has, as a means for coupling and retaining the eyelet 8b of the bayonet, a raised portion or protrusion 10 which has a curved surface and whose dimensions are such as to assume the shape of a half-cylinder or of a hemisphere.

More particularly, the angle "i" formed by the vertical tangent plane that passes through the (generatrix) line 10a of contact between the metal plate 1 and said line of contact must be 90^o, in order to allow the transverse base edge 8a of the eyelet 8b of the bayonet to remain stably in contact with the raised portion 10 when the bayonet 8 is in closed position, as clearly shown by figure 3. In front of the raised portion 10 there is provided an inclined plane 10a which is suitable to facilitate the entry of the bayonet during engagement on the raised portion 10.

Assembly of the buckle therefore entails the initial insertion of the spring 6 between the hole 5 of the button and the eyelet or hook 9 of the box-like body 2, then the insertion of the slots of the button 4, formed by the flaps 4c and by the steps 4e, along the C-shaped edges 1c of the metal plate 1 and the free sliding of the button until its front end 11 abuts against two lugs 2b (figure 3) provided at the open ends of the upper box-like body 2.

Figure 2 shows, in a median longitudinal sectional view, the buckle in assembled form and in the position for release from the bayonet 8, wherein the button is retained against said lugs 2b and its flat underlying surface 12 is practically in contact with the cylindrical lug 10.

To couple the bayonet in the buckle of figure 2, it is sufficient to insert the end of the bayonet in the opening 2a of the body 2 until it is against the step 7 that protrudes from the base of the button and then push the bayonet further until its slot or eyelet 8b straddles the raised portion 10. Once positioning has been achieved, the spring 6 has been compressed and the end of the bayonet, by moving downward until it makes contact with the plate 1, disengages from the retention step 7, so that the button, pushed by the preloaded spring, returns to its initial position; during said return stroke, the bottom 12 of said button moves above the raised portion 10, thus locking the bayonet, as shown in figure 3.

The movement of the cylinder or raised portion 10 as much as possible toward the fixed rear eyelet 1a of the plate 1 and the greater length (with respect to conventional buckles) of the flat bottom 12 of the button allow in practice, in addition to the safety of the locking of the bayonet, the advantage of allowing the button, during release, to shift under the thrust of the spring without swaying laterally and therefore with minimal friction, and of allowing the end of said bayonet not to jam against the front free end of the plate 1 or in any case not to be slowed down during extraction due to the traction at an angle of the strap during release, since said bayonet is inclined only slightly because of its greater length.

Bayonet release occurs by pressing on the button so as to move its flat bottom 12 out of engagement with respect to the raised portion 10; when said disengagement has been achieved, the curvature of the raised portion 10 facilitates, under the pulling action of the strap, the exit of the eyelet 8b of the bayonet without jammings. The button then simultaneously returns into the position in which it is retained against the lugs 2b of the box-like body.

According to the present invention, the opening 2a of the front part of the box-like body 2 also allows the user to easily operate the button even if he is wearing gloves, as usually occurs for motorcyclists.

According to the present invention, the buckle is also provided as shown in figures 4 to 8; in this solution, the system for the coupling and quick release of the bayonet from the metal plate 1 consists in using a bayonet 8 with a single eyelet 8c for adjustable coupling to the strap portion that is rigidly coupled to the helmet; it is constituted by a flat lamina, at the free end whereof, and on the median longitudinal axis whereof, there is provided a protrusion 13 which, according to a first embodiment, is constituted by a hemisphere or hemispherical dome which protrudes from the lower face of the bayonet and is arranged as close as possible to the free end of said bayonet.

A circular hole or cavity 14, preferably but not exclusively of the through type, is formed on the metal lamina 1 and is located so that it can internally accommodate said hemispherical protrusion 13 when the bayonet is fully inserted in the buckle. The stable coupling of the bayonet to the lamina 1 is also ensured by the return of the button 4 to the stable locking position and more specifically by the overlap on the bayonet (at the hemisphere) of the central body 4b of the button (figure 4).

According to the present invention and according to another embodiment, the bayonet 8 can be locked, as shown by figure 8, by anchoring at the end of the bayonet a half-cylinder 13a which is arranged so that its axis is arranged transversely to the bayonet and by providing, in the metal plate 1, a through or blind rectangular cavity 14a.

Said hemispherical protrusion 13 (and the semicylindrical one 14a) can be provided by drawing the bayonet or by welding said protrusion 13 to the face of the bayonet.

Moreover, in order to ensure safe locking stability of the protrusions 13 (or 13a) in the respective cavities 14 (or 14a), a very shallow blending portion is interposed between the flat surface of the lamina 1 and the circular edge of the hemisphere (or rectangular peripheral edge of the half-cylinder); for example, in the case of the hemisphere, said blending portion is tubular, as shown by 15 in figure 6; said blending portion 15 is arranged at right angles to the metal lamina 1 and allows, in this position, to maintain the mutual stable contact of two cylindrical arc portions which are perpendicular to the direction of translatory motion of the bayonet: more specifically, a portion of arc which is constituted by the thickness 14b of the hole 14 of the lamina and an arc-shaped part of the blending portion 13b which is in contact therewith, when the bayonet is inserted and tensioned; this prevents any small plays or movements of the bayonet with respect to the metal lamina from triggering an initial escape of the hemisphere from its coupling hole. Moreover, the internal surface of the box-like body 2 and the external and lateral surface of the button 4 are shaped so as to ensure the stability of the coupling even in exceptional operating conditions.

Figure 2 is a median longitudinal sectional view of the buckle according to the present invention in the assembled condition and in the position for release from the bayonet 8, wherein the button is retained against lugs 2b and its underlying flat surface 4d is practically above the retention hole 14.

In order to couple the bayonet within the buckle of figure 4, it is sufficient to insert in the opening 2a of the body 2 the end of the bayonet until it is against the step 7 that protrudes from the base of the button, and then push the bayonet further until its hemisphere 13 snaps into place inside the hole 14. Once positioning has been achieved, the spring 6 is compressed and the end of the bayonet, by moving down until it is in contact with the plate 1, disengages from the retention step 7, so that the button, pushed by the preloaded spring, returns to the initial position; during said return stroke, the flat part 4d of said button moves above the region for the mutual coupling of the hemisphere and the hole 14, thus locking the bayonet, as shown in figure 5.

The shifting of the position of the hemisphere 13 as close as possible to the fixed eyelet 1a of the plate 1, and the greater length (with respect to conventional buckles) of the locking plane 4d (figure 4) of the button also allow in practice the button to move under the thrust of the spring without lateral swaying and therefore with minimal friction, and allow the end of the bayonet not to jam on the front free end of the plate 1 or in any case not to be slowed down as it exits due to the inclined traction of the strap during release, since said bayonet is inclined only slightly because of its greater length.

The bayonet is released, in this case too, by pressing on the button so as to disengage its flat bottom 14d from the coupling region; when release is achieved, the curvature of the hemisphere 13 facilitates, under the traction of the strap, the exit of said hemisphere from the hole 14 of the plate 1 without jamming. The button then returns simultaneously to the position for retention against the lugs 2b of the box-like body.

The above description clearly points out many advantages, including constructive simplicity, true safety of the coupling of the bayonet, and equally safe and quick release thereof in any operating condition of the helmet.

Moreover, if a hemisphere or a half-cylinder is provided that protrudes from one side of the bayonet, it allows said bayonet to be inserted in the buckle body only if it is kept in a single position, i.e., the position in which the hemisphere is directed toward the plane of the flat lamina 1, otherwise the hemisphere would of course not encounter the corresponding hole and coupling would therefore be impossible.

The invention as described and illustrated above is of course susceptible, in its practical embodiment, of modifications regarding its dimensions, the materials used and other details without abandoning the scope of the protection of said invention.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

A quick-release buckle for straps of full-face or open-front helmets for motorcyclists, cyclists and the like, particularly for use halfway along chin-straps and the like, of the type comprising: a box-like containment body; a metal plate with longitudinal edges folded in the shape of the letter U and provided at one end with an eyelet for coupling to a strap portion which is rigidly coupled to the edge of the helmet; a bayonet having, at one end, an eyelet for coupling to the other strap portion and, at the opposite end, a slot which is suitable to engage a fixed raised portion which protrudes from said plate; and a button, which is arranged in opposition to return springs and protrudes from said box-like body for the actuation of means suitable to allow the release of the bayonet from said raised portion; characterized in that it is constituted by a metal plate with an eyelet for fixed coupling to the strap and with longitudinal edges which are folded inwardly substantially in the shape of the letter C, so as to constitute two sliding and retention guides for a release button arranged in opposition to at least one return spring, said metal plate being enclosed between an upper flat box-like body which is open at one end and a lower closure cover, engagement means being furthermore provided on said metal plate, said means being shaped like a raised portion which is curved in its upper region, like a hole or like a through cavity, and being arranged close to the fixed eyelet of the plate and shaped so as to allow their stable and snap-together coupling to complementarily shaped means formed at the end of a flat bayonet which is suitably elongated and inserted in the buckle between said plate and the base of the button; the dimensions and mutual position of said means rigidly coupled to the plate and of said corresponding means rigidly coupled to the bayonet being such as to allow the button, at the end of the insertion of the bayonet with simultaneous retraction of the button and loading of the spring, to maintain the stable locking of the bayonet by means of its automatic return above said mutually coupled coupling means, the release of the bayonet being achieved by retracting the button into the buckle body.
A quick-release buckle according to claim 1, characterized in that said raised portion with a curved surface is constituted by a half-cylinder or hemisphere which is formed in said metal plate or applied thereon, so that its axis is arranged transversely to said plate, said raised portion being suitable to allow, in any position of the buckle, the release of the slot of the bayonet from the raised portion, said raised portion having, on the side directed toward the bayonet inlet, an inclined-plane blending portion which is suitable to facilitate the entry of a slot of the bayonet during coupling thereof.
A quick-release buckle according to claim 1, characterized in that said hole or cavity formed in said metal plate is substantially circular or rectangular and has dimensions which allow it to accommodate and retain a substantially hemispherical or semicylindrical dome or protrusion which is rigidly coupled to the lower face of the end of said flat bayonet.
A quick-release buckle according to claim 1, characterized in that in order to allow assuredly stable coupling, the surface of the lower face of the bayonet is connected to the circular edge of the protrusion shaped like a hemispherical or semicylindrical dome by means of a cylindrical or prism-shaped portion which has a modest height with respect to the diameter of the sphere or cylinder, said cylindrical portion being arranged at right angles to the face of said bayonet, so as to provide the engagement, in said cavity, between two curved portions which are in mutual contact and perpendicular to the direction of the translatory motion of the bayonet.
A quick-release buckle according to claim 1, characterized in that said hemispherical dome and/or said half-cylinder are provided by means of drawing operations on the plate that constitutes the bayonet.
A quick-release buckle according to the preceding claims, characterized in that said protrusion shaped like a hemispherical or semicylindrical dome is provided separately from the bayonet and then anchored thereto by welding or the like.
A buckle according to the preceding claims, characterized in that said button has, on two longitudinal sides, portions of tabs which protrude from the body of the button and are suitable to form, together with two underlying straight protrusions that protrude from the button body, two parallel U-shaped guides which are meant to internally accommodate the upper horizontal edge of said wings that protrude from the metal plate and thus allow the button to slide in both directions without vertical and lateral swaying or excessive friction between the parts in mutual contact.
A buckle according to the preceding claims, characterized in that said button return spring is inserted with one end in a hole formed centrally in the button body and with the opposite end in a protrusion which is formed correspondingly in the rear inner part of said upper box-like body.
A buckle according to claims 1 and 2, characterized in that said raised portion having an arc-shaped surface is arranged further inside said metal plate, so as to considerably limit the thrusts of the bayonet toward the button and accordingly the locking thereof against the guides of the plate during opening.
A buckle according to one or more of the preceding claims, characterized in that said upper box-like body is open at the front in order to facilitate the actuation of the button and is provided, at the end of said opening, with two lugs which protrude downward and are suitable to constitute means for retaining said button in the release position.