WO2011094874A1

WO2011094874A1 - Screw recess and screwdriver tip

Info

Publication number: WO2011094874A1
Application number: PCT/CH2010/000032
Authority: WO
Inventors: François Brunner
Original assignee: Lemajess Sa
Priority date: 2010-02-05
Filing date: 2010-02-05
Publication date: 2011-08-11

Abstract

The invention relates to a screw (1) which comprises a driving recess with a smooth centring cone (8) and coupling slots (4) enabling a screwdriver tip (2) comprising a conical tip (5) and coupling drives (3, 3a), reacting with the slots of the screw, to ensure fixed locking of the screw on the tip by means of the rotation of the tip. Locking takes place due to friction between the two cones, which are subjected to gradual pressure by the corner effect from a linear axial movement conveyed by a rotating rack of the tip (5), and locking in a final position by means of the reaction on the hooks in the shoulders of the screw (9). The presence of the conical tip (5), which relatively penetrates into the cone of the screw (8) according to the size thereof and the coupling slots (4) valid for all screw sizes makes it possible, in a continuous and linear manner, without skipping fixed sizes, to encompass a broad range of screw head sizes.

Description

screw imprint and screwdriver bit

State of the art

Currently the technique of screwing a screw suffers from many defects that are important: the difficulty, or even the impossibility of screwing caused by the impressive number of existing screw head impressions and consequently the number of tools or bits necessary to operate the screwing without visual guarantees of compatibility or deterioration of the two elements.

There are about fifty bits of different types and sizes of the same type, not to mention the formed of more or less standardized or typed footprints including for example a simple cross or a slot, which may seem sufficient for troubleshooting or the occasional, but by no means for the professionals and the multiple, varied and repeated uses imposed by the production frequencies of the modern techniques.

To be more relevant one can note for a single country, in a non-exhaustive way, that the following models exist: Phillips, Pozidriv, Torx, Schlitz, Sechskant, which must be multiplied by ten at least because it is necessary to a tip for each screw size.

These varieties and these confusions of use of the tips that result from it are wasting a lot of time and enrages users who can no longer withstand the different stages of discouragement before they can finish screwing operations. until the final stage more or less successful.

Often the screw is skewed and almost always its footprint deteriorated unrecoverably to be forced to repeat the operation with another screw, if you can unscrew the old.

Today the confusion is such that some manufacturers of screw or kits, add a suitable tip in the supply of screws to ensure compliance, which increases the cost and limits the variety of use of screws without guaranteeing an absolute way the maintenance of the tip in the footprint as permitted by the invention.

In addition, the possible conservation of these bits, (delivered with the screws ...), for other screws causes the confusion and the total and guaranteed future disarray.

The defects inventoried in a non-exhaustive way are: choice of a bad tip, angle of attack biased, good type of tip but bad size, with consequences: ejection of the tip of the center of the imprint of the screw, rotation without grip or in a vacuum, deterioration of the impression, numerous recoveries and consequently loss of time, money and overflows of stress.

Like any invention of extended right-of-way and replacement, the penetration of the expected perfection will require time which can go from 2 to 5 years according to the forces of technical and economic interference of the developers and manufacturers as well as the objectives of perfections and challenges who can animate them. It can be said that the invention responds to what is specifically sought by the skilled operator: screwing eyes closed in two successive phases, centering and holding until the end of the operation.

The multitude of tips and screw heads that currently exist on the world market, which destroy or diminish their effects between them, due to the small geometric differences, as opposed to the present invention which excludes any manipulation or approximate use , thanks to its total difference, demonstrates that we must seek a solution that is needed to cover all shapes and sizes of screws.

The current system is governed by cruciform screw impressions with resulting tips that destroy themselves by the multiplicity of different solutions, but too identical or similar, by small details invisible to the naked eye, so no one finds theirs and the catches all become flickering and self-destruct after one or two screwing attempts.

One tool replaces all bits or a single tip for all screws.

Description.

To counter these defects described above the invention relies on three objectives joint components of the action of screwing a screw to ensure perfection. It's the ABC of screwing action.

1. - Initially it is necessary to ensure a positioning of the screw followed by a centering of the tool to be screwed on the screw, then a maintenance without interruption and release of this acquired until the end of the screwing operation.

2. - It must be imposed on this screw an axial bearing force, which is centered by itself, followed by a torque, sufficiently stable in engagement, direction and magnitude.

3. - It is necessary that the screw remains spat at the tool, without recovery, until the end of the operation with the maintenance and the progression of the screwing forces.

In addition, as constructive advantages inherent to the system must be added:

1. - The set controls itself because if the use is not correct the needle is not stable and the screw is unhooked which shows that there is an incompatibility, either at the level of the tool, at the level of the screw.

2. - The screw is tightened by itself on the tool by the only force of rotation. Axial support force is no longer predominant as in current processes; it is not even necessary after the catch since there is self-tightening, only the force tangential torque remains, with a simplified effort, since there is reduction by the effect of a rack that requires a maintenance with wedge effect.

This operation of maintaining the screw is comparable to that of a drill bit fixed on a mandrel without being held prisoner until release with the need for the use of a key, which would be a too complicated handling and not adapted for the screw; it is necessary that at the end of the screwing the whole is released of itself automatically.

The invention is made possible by the fact that a screw transmits the constraints of screwing and end use to its periphery and that few force lines are located in the axis or in the center of the screw head, so that this free zone can be used for the screwing device for the transmission of the forces involved.

For the desired screwing action the few lines of force possibly alienated are pushed towards the periphery without changing or reducing the clamping forces provided or the stresses and strength of the materials used for the screw in its final function.

The centering being primordial, but nonexistent at the moment of the technique, a use of the central axial volume of a certain angle and a certain depth is possible.

The opening angle B, 7, is the one and only constraint required for all screw sizes for screw manufacturers. The needle 5 of the described tool, which supports the centering and screwing forces, adapts to each depth, so to each screw, thanks to the opening of the same angle for all the screws 1.

The tip 34 is the same for a small or a large screw because for the small screw is used only the tip and the rest becomes useful for the following sizes, especially the centering cone 7 of the needle which sinks more or less deeply depending on the size of the screw which allows to receive a cone of centering longer and longer and open in the center of the screw.

The angle β must be between a maximum and a minimum which ensures the best friction surface between the cone of the cavity 8 and the needle 5 of identical shape by a corner effect which also depends on this angle.

This universality allows the use of a single tool for the 90% of the screws commonly used. So that the 100% of the screws would be covered by 3 or 4 tools while applying the same principle and moreover, these different types of tips, of different sizes, are also overlapped between them, so that we do not is that rarely caught off guard on an unsuitable scale average of the tip on a screwdriver or an electric screwdriver.

One could classify the sizes of the heads by different categories like micro, S, M, X etc. to encompass all screws from 0.5 to 10 or 15 mm, micro for use in miniaturization or watchmaking.

There are even electric screwdrivers with two chucks on the same motor, one for the drill bit and the other for the screwdriver bit. There is a huge saving time and attention if the screwdriver remains the same, which will not be the case for the different diameters of the drill holes per bit which each time requires a different wick diameter and suitable for the material to be drilled. This remark also demonstrates the enormous benefits that can be achieved on automatic assembly lines.

The solution becomes facilitated on the screwing mandrel by eliminating the large amount of bits that had to be on hand and which was larger than the number of locks because of the types of fingerprints, since virtually variables depending on each manufacturer, for each screw size, these differences are rarely seen with the naked eye.

The effect of maintaining by hooking in the impression is essential because it ensures the holding of the screw like a drill bit to drill. A test of the good performance of the devices provided by the invention consists in holding the screw at the end of the tool without losing it.

This feature becomes an advantage, even an obligation, for the application of self-drilling screws or screws because the screw can be held almost as well as a drill subjected to significant force and direction drilling pressure. the direction of the axis of the screw-drill and not only in torque torque without direction ensured as for a conventional screw.

The wedge effect is essential, ie the more it is used in rotation in the screwing direction, the more the forces of holding and screwing in games increase or the impossibility slip, ejection, stall or break is guaranteed. Especially the initial centering on the screw, so hazardous and imprecise in the current technique, is thus guaranteed at first sight by the initial presence of a pointed needle that it is sufficient to position approximately in the hole of the opening so that the rest is done automatically by penetration.

A major consequence of technical progress of the invention, comprising two related products, the screw and the implementation tool, is in the elimination of all categories and sizes of fingerprints, because the tool has a Globalization feature that spans a variety of screw sizes.

As the dimensions are in the order of a millimeter, the material resistances and accuracy required correspond to techniques and tolerances that are similar to those of watchmaking or the knowledge of the manufacturers of pens, ignition lighters or other fine mechanical and resistant.

There are many systems with duality of the screw head and tip allowing the transmission of screw forces, but all existing solutions are based on various shapes, wavy, cruciform, cylindrical or conical and even with corner effects between the opposing forces by helicoidal shapes that immediately impede the relative movement between the two elements in the penetration of the tip into the cavity of the screw head while the present invention provides an initial movement of pressure and rotation of a certain angle of rotation without taking a smooth conical needle allowing the search for hooks that submit the assembly at pulling forces for the hooks and compression for the needle which finishes its stroke by a total blockage caused by the increased forces of a wedge effect on the needle.

This feature differs from existing solutions which have in certain axes, lobes, grooves, surface lines of a certain angle or a certain curve with respect to a straight line parallel to the central axis of the screw and / or the tip while the present invention has a cone which any generator is in the same plane including the central axis for all and any cut around this axis. Any axial section is formed of two straight lines exclusively.

The smooth central cone as single and simple socket cavity of a screw head is found in no existing solution, as are the forces in action during the screwing rotation which even allows the cancellation of the axial pressure force while for all the other existing solutions, the pressure force is decisive and must be important, maintained and even pushed to the extreme in the final phase, on pain of failure or deterioration of the footprint, until the end of screwing to ensure the goodfacture.

The tightening of the screw in the current technique is transmitted by the grip between the tool and the footprint of the screw by the contact on one or more points or a few lines, which causes concentrated high stresses likely to damage the geometries and to destroy the catches, while the solution of the present invention rests on the contact of stronger and stronger, by wedge effect, between two surfaces in intimate contact to better distribute the stresses, these two surfaces are represented by each of the conical surfaces in pressure of the impression and a needle.

The calculation of this surface S corresponds to:

p as depth and r = d / 2 as radius, being lengths measured on the cone of the screw cavity, (fig 14).

It should be added that this surface does not necessarily have to be as large as possible, since the smaller it is, the more the specific contact force per unit area that causes the friction and then the blocking is high.

Example with p = 7 mm, r = 4mm, resulting surface 100mm ² .

These surfaces are maintained in progressive pressure contact by taking hooks in reaction. The solution is facilitated by the inequality of the resulting construction accuracies. Indeed, the hooking by hooks are of a degree of precision almost indifferent, only the surfaces of the cone of the screw and the cone of the needle must be precise to guarantee the best friction between them which ends with a blocking to lead to pressure by wedge effect that prevents any failure of screwing.

The tip of the tool which presents the desired precision needle 5 is part of a set of actuating means that increase the construction of the tip. But it should be noted that the price of the tip is spread over a multitude of use for hundreds or thousands of screws. It is a tool with precise miniature components that raises the price but when we take into account the prowess in this area we can easily admit that the solution is affordable at a reasonable price. A good, perfect tool is priceless, especially if it is to use it often with delight and wonder, to spread its cost over a multiple in the thousands, with covers that replace a multitude of different shapes and sizes by universality.

In addition, we must build a tool with a strategy in the field of "fale safe graduate" which consists in imposing hierarchy in breaks, which implies, in the present invention, that if something must be dropped first, if the stresses are pushed to the extreme, it will be the screw by its shoulders that are subject to tearing and not the tool that must always resist. In fact, knowledge in metallurgy makes it possible to adopt foolproof metals for the most constrained parts in the act of screwing.

The screw recess comprises a negative cone centering cone aperture 8 (FIGS. 3-14 and 15), or female aperture slots 4, (FIGS. 3-6-8-14 and 15) into which are introduced by axial pressure on the tool of the hooks 3, (fig 1 -2-3-4 and 17) which ensure the tightening for the tangential transmission of the forces of the tightening torque. The impression of the screw 1, (fig3-4-6-14-15 and 16) is struck by a shoulder 9 (fig 6) to receive the lug of the hooking socket 19, (fig 6 and 17) .

The crotch slots 4 on the cavities are identical on all screw sizes. The geometry of the profile is typed, identical for all the screws and its radial length is traversing on the head of the screw, so that the more or less important resistance requirements for a large or a small screw are in the length used by the spur of the catch more or less long.

It should be noted that these slots can be very thin and not very precise since all the forces present once positioned put the hooks under tension during the clamping to hook, the accuracy is imperatively in the contact surfaces of the centering cone of the screw and its opposite on the needle.

The tip that transmits the actuating means. consists of a rotor 2 (fig 1 -2-3 and 4), a sleeve 1 1 (fig 1 -3-1 8 and 19) and a needle 5 (fig 1 -2-3-4 -16-1 8 and 19), sliding inside the sleeve, representing the positive shape of a corresponding negative shape formed as a fingerprint on the head of the screw. The rotor 2 and the sleeve 11 are movable together by a bearing 16 (FIG. 2), allowing mutual rotation. The rotor comprises inside a longitudinal groove 12-12a (figl) allowing the driving of the needle by a pin 13 and 13a (1 and 2) in all the driving positions.

This needle 5, which can be conical or have any progressive shape with or without intermediate shapes, is automatically positioned by pressure to enter the cavity 8 and center itself.

If the pressure is released, the needle returns to its initial extracted position by the effect of a spring 15 (FIG. 1, 2, 3) antagonistic in both directions, tangential and axial rotation.

At rest, the needle 5 leaves the sleeve 11 of the nozzle until its maximum total extraction limited by an end stop.

This feature also ensures the automatic control of the proper functioning of the tool by detecting a possible abnormal blockage, if the needle does not come out of the sleeve as described, including the stitches which must all be on the same level perfect plan. A mark on the tool can be engraved to show normal correspondence.

With the finger one can also control if the hooks are free of movement against their springs, as an example 17 (Fig 13) for retraction.

In the joint effect of the needle and the hooks it is necessary to transmit forces of application and rotation the most distributed and continuous possible. In this sense it is necessary that the conical surface of the needle participates by friction and blocking the transmission of the tightening torque.

There are two concentric and coordinated moving parts. The rotor of the nozzle which transmits its rotation to the needle and the sleeve which have the catching hooks in reaction on the screw.

The movable needle inside the nozzle moves in rotation within the limits of stops at rest and maximum displacement during screwing expressed in degrees of rotation.

Following the pointing operation, the rotor of the tool must be subjected to an axial pressure action, then to a rotation, at an angle of 0 ° degree at a maximum angle limited by a stop. To impose the return of the needle in the initial position of angle 0 °, a proper tension spring 15 imposes this return, it being understood that the primary return must be done by the operator in the opposite direction of the screwing.

The needle and the sleeve are each provided with a thread 20 and 21 (FIGS -18 and 19) which force a progressive axial movement to obtain the frictional clamping.

The threads are designed to ensure clamping in any position of depth, therefore of screw size. For this purpose a neutralization angle of 0 ° to approx. 30 ° is provided so that the threads are neutralized to allow the movement of the needle 5 and the hooks 3 in the crunching slots 4 and the opening of centering 8.

At position 0, ie at rest, the sleeve has no threading on its periphery on the sector of approximately 30 degrees. to allow the needle to slide to the desired depth in the cavity. A neutral zone of 30 degrees approx. which follows, is also retained, having no thread, neither on the rotor nor on the sleeve e (fig 18 and 19), to avoid unwanted gearing. The clutch, in the threaded rack, is made following a certain rotation of the rotor of the bit from a certain gear angle to the maximum of 300 degrees remaining after all the hooks have found their respective slots and the needle its desired depth.

These hooks are distributed peripherally on the head of the sleeve around the needle and their number is not limited, but for reasons of symmetry, the even number is required. The higher the number, the higher the stalling and clamping effect is important and desirable. The screws may also include a number of slots variable and independent so that the hooks of the tip will penetrate only in the existing slots, the remaining remaining retracted. So that the system is universal so it is important that the tip has a number of adapted hooks, for example with six slots, (Fig 8). The distribution of the slots on the impression will also have to respect the divisions in angle, so that the hooks can find their housing in the actually existing slots.

The sleeve can also be cut at the ends to form peripherally directly the hooks without intermediate parts. The stakes can be built in the form of petals that open or close by following the needle in all its length by deviating in the action and returning to its original position by the elastic effect of the petal concretized by an elastic rod 18 (Fig 4, 7 and 17) between the support on the sleeve and the hook which ends with a lug. The elasticity of the elastic rod can adapt and receive the appropriate index and its resistance to screwing by the choice of material and the progressive shape blade, circular or triangle that binds to the body of the sleeve to transmit the constraints.

To allow the setting up of the staking hooks it is necessary to leave an intrinsic freedom of movement in the axis of depth, is the movements of search to find the specific slot and to pass under the shoulder 9, that is to say 0,5 to 2 mm of depth. The hooking must therefore slide elastically on itself in this margin to be fully extracted at rest and the spring bandaged if the hook does not find its place in a slot of screw head.

In a useful way the bases of the lugs of the hooks 23 and 24 (Figs 1 1 and 12) must be constructed with a rounded to facilitate the penetration during the search for the slot.

An example of construction of the hooks may be in the form of a flat portion according to a blade made of material allowing the spring effect fig 10. A useful and simplified variant is found in the bending of 90 ° for the extreme part, thus being able to serve as hook fig 1 1, end 23-24 with its incorporated pin 23 produced by the folds of 90 °.

The anchors of the catch 25 (FIGS. 3 and 4) can be carried by a collar on the sleeve 26 (FIG. 4) in a sufficiently elastic manner to ensure the search for the corresponding slot which can be within the tolerances of machining and different shape. In particular the hooks must receive sufficient freedom of movement in the axial direction to allow a retraction in case of non-existence of slot according to the number of existing slots or not on the screw head. An advantageous solution can be found in the formation and the use of the upper end 17 (FIG. 13) to form a spring on the same piece which is bandaged with the pressure on the tool, or in search of a crack and free extract at rest.

Also in a useful manner this rod of the hooking socket may also comprise the stopper 27 (FIGS. 11, 12 and 13) which limits the movement of the hook in the search zone of the slot, this stop finding its groove 29 (FIG. 17) with limited movement in the hook or collar holder 28 (FIG. 17). The independent spring solution, can also solve the problem of voltage and path required.

Fig. 15 also shows another form of screw head. This example shows in a relevant way that the needle remains the same and that the passage profiles of the pitch slots remain the same, the profile existing over the entire radius of the diameter of the screw head.

For the screw it is necessary to tend towards the maximum increase of the depth p, (fig 14 and 15), while leaving enough size for x which depends on the resistance of the materials for the screw and q (fig 6) which must leave a sufficient grip for the hooks also dictated by the strength of the materials of the screw. Only the angle β remains constant to be respected by all manufacturers.

The use is dynamic since the needle is frictionally clamped inside the cone by the wedge effect imposed by the threads built on the two moving parts to form a rack 35 (Fig 1). The cone of the tip must be able to turn and lock quickly by progressive tightening. It should be noted that once the setting of the threads reached, the rack imposes axial movements of the order of one hundredth of a mm.

The tolerances between the two conical surfaces must be adapted and the state of the surfaces in contact must correspond to a compromise between the total smooth and the rough which should counter a villainous impurity, of fat for example, likely to prevent any blocking even with extreme forces produced through the rack by squeezing.

In this sense a slight surface treatment, such as more or less marked sanding on the penetration head of the needle, can remedy these risks of contrariant slip.

It is necessary to demonstrate, with respect to the known methods limited to the screwing of a screw, the accumulated centering and clamping by the present invention which results in a separate progressive dynamic process of increasing the forces in play which are all exerted , in a collected manner, inside the upper circumference of the head of the screw, therefore in a restricted approach volume. The economic gains appear important from the outset if one takes into account that the corresponding times and wages take more and more a primordial relative value. In developed industrial countries, the working time of the operator counts more and more.

The economic values in play also plead in favor of the proposed invention, to mention the most important, the hourly price of the operator. We take the screw and we put it without delay and act failed or screw destroyed or looking for tip.

Properly constructed with the necessary precision and materials, the invention has an important and universal economic value, just think of the millions of screws that are used every day, in the factory, on the job site or for any other purpose, such as DIY or Hobbies.

In some cases of work, the screw head must remain perfect for aesthetic reasons. In this case, the invention ensures this requirement because the endpiece will not have destroyed or damaged the impression by the recesses, the resumptions or the numerous slips due to the rotations which can even leave sensitive asperities on the finger or completely destroy the impression profile.

In some cases of visible requirements, the planned footprint, corresponding to the invention, also allows to receive an aesthetic cap that will take place and remain by maintaining the asperities of the hooking of the screw head.

In another case, for reasons of security, the fact sought to render The screws of some devices (electric for example) can not be dismantled. This plug completely meets the objective. In the case of the footprint with a hooking slot retraction becomes impossible, which is not the case today with special imprints of limited use by the lack of adequate tips like a key in a lock, but you can still get at a hardware store that has all the existing bits. In our case, with a cover irreversibly crooked, disassembly is completely impossible, except damage to the entire protective body of the electrical device. The need for a special imprint, inviolable, is avoided.

In other cases this technique also makes it possible to make the unscrewing of certain appliances in public places, such as toilets, lounges, etc., unscathed by the application of a smooth plug which will be hooked by its claws on the imprint of the screw head. These irreversibly gripped caps can give the illusion of a rivet head made of plastic or metal.

Brief description of the drawings.

Fig 1 shows the tip at rest, in axial section, with the needle punched out, pushed by the spring.

Fig 2 shows the tip, as it would appear completely pushed on a flat surface, to allow, for example, to control its proper operation by the effect of the springs.

Fig 3 shows the tip with a screw in action and the presence of two different hooks. The rotor is rotated by a certain angle of rotation.

Fig 4 shows the tip in action with its fully retracted needle and the hooking in contact on the needle through an elastic rod located between the support housed in a collar and a hook turned 90 degrees.

Fig 5 is a cross section CC which shows the hexagonal portion of the rotor allowing the transmission of clamping forces on the tip.

Fig. 6 is a partial axial section AA 'showing the taking of a hook in a hooking slot of the thumbprint with a catch pin and a shoulder of the slot.

Fig. 7 is a longitudinal section in a pushed-up position on a plane showing another form of hooking with a 90 degree spring-backed elastic rod and a helical surface treatment on the tip of the needle. Fig 8 shows a top view of a screw head with its imprint showing the circular centering aperture and the crosstalk slots in number of 6 units.

FIG. 9 is a diagrammatic plan view showing the possibilities of distribution of the hooking sockets for 2, 4 or 8 locations as well as a curved sipe to adapt to the roundness of the support.

Fig 10, 1 1 and 12, show different 90-degree return stitches with different hooks or lugs.

Fig 13 shows a machined resilient shank stud with incorporated spring and stop.

Fig 14 and 15 show the axial section of a typical screw with the geometrical magnitudes for the centering apertures and the cracks.

Fig 16 shows a schematic section with the use on a large or a small screw.

Fig 17 shows the schematic solution of an execution of a catch of staking having on the same organ the stop, the spring and the hook as fig 13.

Fig 18 and 19 show schematically the distribution of the threads on the sleeve and on the needle with the reciprocal absence in position a and b, as well as the total absence of threads on the two parts in e.

Figs. 20 and 21 show a method of making an impression on the screw head by successive strikes to stamp the slits and voids under the shoulders. The drawings are explicit by their mere examination, as an example of execution, without limitations in the details of the principle of the invention.

With reference to FIGS. 6, 14 and 15, a relatively simple but specific screw 1 comprises two parts, the cone 8 characterized by its centering aperture diameter d and its depth p and the hooking slot 4 drawn in section. . This section shows the hooking slot of length m and depth n and of width o having a shoulder 9 leaving a depth q on FIG. 6 which can be rectangular or trapezoidal to favor the hooking effect of the male part or pin 19 of Figure 6 located on the stall pin.

With reference to FIGS. 1 and 14, the angle β 7 of the cone is constant, which makes it possible to vary its diameter d or its depth p as a function of the size of the screw and the calculations as a function of the strengths of the materials.

The angle β takes into account the largest available space while ensuring the wedge effect and the strength of the screw, the x, y and z magnitudes, the total width being z = 2x + y according to fig 14. The more the angle is closed, the higher the perpendicular force component on the surface of the cone, which determines the wedge effect, is high, the compromise being for the same angle in the depth variable depth p at the choice of the screw manufacturer.

The width z = 2x + y corresponds to the diameter of the screw and is also at the most constrained passage that must allow the diameter y as high as possible according to the angle β, so the greatest depth p possible. After the rotational movement, which sets up the system for a certain angle of rotation, occurs the greater or smaller clamping between the depression of the needle and the retention of the shoulder 9 and the hook 3 in the cavity of the screw.

At rest, at the 0 ° angle, obtained on a stop and thanks to the return spring 15, the needle is completely extracted from its body, or to another maximum ejection stop 13.

The spring 15 has two functions, one axial which pushes the needle outwards at rest and the other tangential which performs the return of rotation of the needle to the rest position when releasing the screw forces in games.

Between 0 ° and 30 °, the needle only has a screw pitch, the sleeve has no thread in this area, which allows it to slide in the right depth of the screw before setting by rotation for a 30 ° angle + 30 degrees, the next 30 degrees showing no threading, neither for the needle nor for the sleeve. Figures 18 and 19 schematically show the threading in the area (a) 20 for the needle 5 and the zone (b) 21 for the sleeve 11, e being a neutral zone of approx. 30 degrees, with no screw on either side, the rack to engage in contact with the gearbox over the remaining 300 degrees.

It will be easily understood that by pressing the needle into the screw, the stroke will be defined by the depth of the cone excavated in the head of the screw. At this moment, following the rotation, the tightening and the locking effect takes place by the threads 20 and 21 forming the rack and the catch hooks 3, 3a and 19 in the crunching slots 4. For small screw dimensions the movement of the sleeve vertically would make it impossible to approach the slot of the screw by the proper hooks 3-3a fig 1 which follow the movement. These hooks attached to the sleeve do not follow the angle of the needle β and would be positioned next to the slots of the screw. To fill this impossibility the stitches are flexible to open or close like a flower petal on the needle. For this reason, these hooks 3 and 3a are fixed on the sleeve on the outside by means of elastic rods 18 (FIGS. 4-7 and 17), the spring effect being towards the central axis for holding the hooks against the needle regardless of needle punching.

For small screws the contact is towards i fig 7 and for large screws, ie a greater depression of the needle, the position of the hook with its lugs at the ends is in j fig 3.

For larger screws, or when the limit of action dictated by the distance g fig 3 is greater than the radius of the cavity of the screw, the effect of recall of the catch of staking 18 in the shape of petal mobile and solidarity of the needle is no longer necessary. The hooks can be directly on the crosstalk slots, which further strengthens the rigidity of the sockets allowing forces in games larger for large screws, while recalling that the two systems overlap without excluding.

Fig 16 shows schematically the utility of the same tool with its needle for a large and a small screw. The drawing of FIG. 3 shows a screw socket for which the existence of the hook which follows the spring needle is not necessary. For this screw a tool of the higher size class would be justified, which also shows the overlap on a wide band of the use of the tool.

The tip has at the end of the top 34 fig 3 a conventional hex socket for each screw machine or screwdriver, cut CC fig 5.

FIG. 1 shows the presence of a circular return spring for the 2 moving parts, ie the sleeve with the fixing of the spring at 30 and the rotor with the attachment at 31.

Fig. 2 shows the solution of a cut-out directly in the cylinder of the sleeve 1 1 of the jacks 3b with or without hooks or lugs. In this case the rods and anchors are avoided. The hooks can be formed directly at the ends by folding and / or turning of the cut parts, which avoids the addition of a pin with axis of rotation 3b to follow the angle of adaptation in the slot of the slots according to the spacing catches. These small angles can be overlooked.

Figs. 20 and 21 disclose a method of manufacturing a screw footprint by successive time-shifted keystrokes. The first strike, concretized schematically by the stamp or punch 40, shows the rectangular slot of depth n. The second striking, concretized by the stamp or punch 41, associated with a slider 44, offset by a time in relation to two successive material movements with their inertia, makes the vacuum appear under the shoulder 9 of the slot of hooking of the screw. The moving parts being moved by shock shots their returns to the initial positions are provided by specific springs, 42 for the slide, 43 for the stamp or secondary punch 41 and 45 for the stamp 40 or primary punch.

It is understood that the embodiments and variants described above are not limiting and can receive any desirable and useful modifications within the scope defined by the claims or extrapolation of these limits. In this order of limitations all kinds of particularities may appear, during subsequent developments, such as for example the shape of the hooks 23 and 24 Fig 11 and 12 which may have a rounded or any shape facilitating the search and penetration into the slots or the angle of attack of the hooks in the axial direction. The degree of freedom of automatic adjustment of the hook in its support out of the screw must have a maximum in the axial direction but no freedom of movement in the tangential direction.

In extrapolation it is possible to admit the solution which would consist in printing on the cone of the helicoidal plugs 32 fig 7 superimposed, facilitating the movement and the locking of the rotating needle while maintaining the obligation of movement by friction when looking for the slots of crochage.

Claims

claims

1. - A system comprising the effects of a screw (1), a drive tool tip (34) and coordinated actuating means characterized by a screw head recess having a centering aperture (8). ), located centrally in the axis of the screw, adapted to receive a needle (5) of the drive end complementary to the centering opening (8), the centering opening being surrounded on its head , of crunching slots (4), allowing the catching hooks (3), located on the endpiece, to integrate the slots for hooking (4) of the screw, links which connect the screw and the endpiece being energized, by means of actuating means, by forces which result from the pressure and rotation forces applied to the tip.

2. - The system of claim 1 characterized in that the actuating means create links, formed by the needle (5) which is embedded in the centering opening (8) and by the catching hooks ( 3) of the tip which integrate the slots of the hooking (4) of the screw, these connections are put under tension by the penetration of the needle and the rotation of the tip to form and transmit axial forces in the direction of a compression for the needle of the tip (5) in the centering aperture (8) of the screw and traction on rods (18) of the catches (3) connecting the crunching slots (4) of the screw and the anchors (25) of the rods on the tip.

3. - A screw forming part of a system comprising a screw (1), a drive tool tip (34) and coordinated actuating means characterized by a screw head recess having a centering aperture (8), located centrally in the axis of the screw, the centering opening being surrounded, on its head, crosstalk slots (4).

4. - The screw according to claim 3 characterized in that the centering opening (8) of the footprint of the screw corresponds to a smooth cavity of substantially conical or slightly cylindrical geometry or any other form of circular section or slightly eccentric or slightly polygonal with an opening angle β (7) determining, this angle unique defines the diameters (d) of the cone of the opening and the depth (p) of the smooth cavity allowing the penetration of a needle (5) of the tool of complementary conical shape for different depths of different screws.

5. - The screw according to claims 3 and 4 characterized in that the angle β (7) unique and of identical size for all screw sizes, which determines the surface of the cone that participates in friction and blocking by wedge effect advantageously lies between a minimum of a few degrees and a maximum to ensure a useful component of force, perpendicular to the friction surface, the decomposed axial force applied to the tip.

6. - The screw according to claims 3 and 5 characterized in that the axial section is identical for any section around the central axis of the screw and that it is formed exclusively of two straight lines to form an angle β whose sides in a straight line are in the same plane with the central axis of the screw (10) which generates these lines, devoid of any profile, to form the centering cone of the centering opening (8) of the the impression of the screw, the cross sections being formed of circles (8), devoid of any profile. All axial sections consist of straight lines devoid of any broken patterns or lines and all axial sections are formed of circles devoid of any broken profile or line resulting from profiled section fingerprints such as the existing six-lobe or groove imprints of other inventions.

7. - The screw according to claim 3 characterized in that the crosstalk slots (4) of at least two units distributed at the periphery of the centering opening (8) equidistantly and over the entire length of the diameters on the impression of the screw according to radii passing through the center of the circle of the centering aperture (8) are formed of a profile of passage (4) of a depth (n) and a width ( o) may comprise geometric shapes capable of ensuring the penetration and the stalling of the hooking sockets (3) of a nozzle, with shoulders (9) capable of blocking the withdrawal of the hooks (19) under tension, a shoulder adjacent (9) to the a hooking slot (4) leaving free a movement space (q) provided for the passage of the hooks in the penetration and withdrawal phases during the act of screwing.

8. - The screw according to claims 3 to 7 characterized in that a mechanical object for closing the cavity may comprise penetration portions similar to the centering apertures (8) and the hooking (4) to form a useful plug .

9. - An endpiece constituting part of a system comprising the effects of a drive end (34) of a tool, a screw (1) and coordinated actuating means characterized by a needle of the drive end (5) and the stitches (3) located on the end piece.

10. - The drive end according to claim 9 characterized by:

(a) a sleeve (1 1) needle holder (5) having movable pinch plugs (3) and a thread (21) on the inner surface for transmitting the forces on a needle (1 1) via a rack (35) which adapts to the resulting depth of penetration (p).

(b) a rotor (2) having, on the one hand, at least one groove (12) to allow at least one pin (13) corresponding to a needle (1 1) to slide thereon and secondly , a bell tube (36) for guiding and actuating an elastic member (15) when said rotor is subjected to pressure and rotation for the purpose of transmitting forces to the needle (7) via a rack and pinion (35).

(c) a needle (5) which is movable and slidable in the rotor (12) and the sleeve (11) and which is fully extracted in the rest position and completely retracted into the maximum use position, in relation to with the depth of the opening of the screw head (p) and provided on the one hand with at least one pin (13) driven by the rotor (2), for sliding in said groove (12) of the rotor, on the other hand a guide rod (37) penetrating into said bell tube (36) of the rotor (2) and on the other hand a thread (20) on the outer surface intended to take hold for s' mesh on the opposite thread of the sleeve (1 1) for transmitting forces via said rack (35).

(d) at least one elastic element (15) for pushing the needle outwards, located between the rotor (2) and the needle (5), which is relaxed at the rest position and tensioned during the act screwing by the external forces of pressure and rotation transmitted on the rotor (2), this elastic element (15) being able to relax in the axial and tangential direction to allow the recovery of the initial rest position determined by adequate stops.

(e) a holding ring (6) for accommodating at least one thrust bearing (16) and at least one resilient means (30; 31) with a circular action for returning the rotation of the rotor (2) relative to the sleeve (1 1) following loosening of the clamping forces.

(f) a thrust bearing (16) located in said holding ring (6) between the movable rotor (2) and the sleeve (1 1) to allow their precise relative rotational movements during the transmission of the clamping forces .

(g) a retaining collar (26) of the anchors of the moving pinch jacks (3) located at the end around the periphery of the sleeve (1 1) allowing the initial assembly and the fixing in precise but elastic positions of the catches stakes comprising a rod (18) connecting the anchors to spikes (19).

1 1. - The tip according to claim 10 characterized in that the needle (5), fully extracted at rest, has a complementary conical shape with a single angle β (7) which is between a technical minimum of a few degrees and a useful maximum for participation in friction and blocking by wedge effect.

12. - The tip according to claim 10 characterized in that the stitches (3) are fixed or housed at the end of the sleeve (1 1) on elastic supports arranged and held by the collar (26). to absorb at least the path corresponding to the depth (n) of the passage profile (4) to allow their retraction when the number of crunching slots (4) of the impression is not identical to that of the number of staking takes (3) or in the search phase of the slots (4) controlled by the pressure and the rotation of the mouthpiece.

13. - The tip according to claims 9, 10 and 12 characterized in that the catches (3) are formed of an elastic anchoring (14; 17; 25), a connecting rod (18) and hooks in the form of lugs (19), the elastic rod (18) being executed to advantageously follow the surface of the needle (5) in order to force the contact (j) between these two elements, the elastic effect being the most tensioned at rest, the needle (5) being protruded in this position, said rod (18) being straight or curved, of different sections advantageously to absorb the total rigidity in the circular direction of the sleeve (11 ) and the best elastic movement in the direction of the contact against the head of the needle (j) penetration, said rod may be twisted to form an angle of env. 90 degrees between the anchorage tangential to the circumference of the sleeve (1 1) and the line of the rectilinear lugs (3).

14. - The mouthpiece according to claim 13 characterized in that the catching pinches of the tip (3) are provided at the ends of hooks with an articulated pin (3; 19; 23) of a profile allowing penetration into a hooking slot (4) of the screw cavity and the blocking of one side only under the shoulder (9) with which the contact is established, thus preventing the escape during tightening but allowing the withdrawal during the relaxation of the clamping forces caused by the reverse rotation operation, the opposite side of the pin being smooth and adapted, rounded, without roughness or angle to allow the passage of the hook with the pin (19), when the introduction or removal of the hook from the hooking.

15. - The nozzle according to claim 10a and 10c, characterized in that the respective threads (20; 21) on the sleeve (11) and on the needle (5) have a coordinated pitch and direction for meshing. and allow the needle (5), following an angle of rotation of the rotor, forming a rack (35) to impose the needle (5) a straight path of a short length may include fractions of mm corresponding to the clamping and locking of the needle (5) in the friction phase and blocking by corner effect that follows.

16- the nozzle according to claims 10 and 15 characterized in that the threads of the threads (20; 21) are on all the respective axial lengths of the needle (5) and the sleeve (1 1) but not on the circumference circumference circumference of 360 degrees because distributed by sector, ie a sector of approx. 30 degrees for needle threading (a) followed by a neutralized zone of approx. 30 degrees (e), without any net, neither on the needle nor on the sleeve, then the balance of approx. 300 degrees on the sleeve (b) to allow, from the rest position defined by a stop which stops the return of the sleeve (11) under the influence of the circular elastic return means (30; 31) of the rotor relative to the sleeve , to find the different depth of action (p) for each screw size, by pressing on the tip, the neutral zone (e) ensuring the free passage of the two nets between them without risk of early engagement, this pressure movement being followed by a rotation to allow the search for the crotch slots (4) and then allow the threads (20; 21) to mesh after the passage of the neutral zone to activate the rack (35), this which causes the needle (5), the hooking jacks (3) of the sleeve, the elastic thrust means (15) and the circularly elastic return means (30; 31) to be put under tension, the pressure on the needle (5) transmitted by the rotor (2) after passing the neutral zone ie the gear rack (35) is no longer needed, only the rotation is necessary with the high forces of the final screwing.

17.- The nozzle according to claims (10, 15 and 16) characterized in that the elastic means with circular action (30; 31) located in the holding ring (6) are formed of one or more parts, comprising an end (31) fixed on one side on the rotor (31) and on the other side an end (30) fixed on the sleeve (1 1) with differentiated elastic coefficients to take into account the path of search slots (4) and the rack gear (35), the gear must not be activated in the search phase of the cracks slots.

18. - The nozzle according to claims 9,10 and 1 1, characterized in that the surface of the needle (5) intended to take action in the centering opening (8) is treated to respond most advantageously to the function friction by having small protruding portions (32) obtained by surface treatment, such as sanding or distributed on the surface by applying very strong minute parts in a uniform or distributed manner, according to helical or progressive geometric shapes, which promote movement and / or friction when penetrating the needle (5) to achieve the most necessary reaction resistances most useful for friction and final blocking by wedge effect.

19. - The tip according to claim 10 characterized in that the hooks are cut directly on the sleeve and receive the shapes and elasticity that allow the ends to follow, as the depression of the needle, the contact (j ) against the cone of the needle in both directions in the direction of the axis of the cone of the needle or negative deviating from the axis of the cone, the ends may comprise resilient movable lugs about an axis.

20. - A method for manufacturing the print of the screw characterized by the use of a stamp comprising a cone and one or more parallelepipeds of rectangular section called punch, around the cone for striking the centering aperture of the screw, sliding in a die (39), said punches containing on the one hand a primary punch (40) for striking, thanks to the striking given at the top (A), an opening for the formation of form catching rectangular and of adequate depth and secondly, a secondary punch (41), struck at the top, inside the primary punch (B), in a time delay compared to the striking on the primary punch, to allow the moving a slide (44) in a movement perpendicular to the axis of the striking or slightly biased, intended for hitting a rectangular opening corresponding to the opening of the hooking (4) and revealing the shoulder (9) of the opening of the hooking slot of the screw (1), the two striking phases being followed by elastic members , (42,43 and 45) for recalling moving parts in the initial rest positions.

21. A method of using the tip characterized in that the process is divided into several successive phases which consist, in a first step, of introducing the needle into the centering opening of the screw by a pressure axial to the bottom of the centering cone, in a second step, this pressure, axially maintained, is followed by a rotation action, by adding a screwing torque on the endpiece, according to a certain angle of rotation, which allows the search and the taking of the hooks in the slots of the screw to reach the objective of stalling which fixes the end and the screw in the bayonet way, in a third time the axial pressure can be released to continue a rotation only which engages a rack, turning a rotational movement into rectilinear motion to create a frictional pressure between the two cones, that of the screw and that of the needle, which brings a final block at all to turn the screw juice only to the final goodfacture.