CH712544B1 - Torque tool, especially a screwdriver or wrench. - Google Patents

Abstract

The present invention relates to a torque tool, in particular a wrench or a screwdriver, for example a watchmaker's screwdriver. The key comprises first and second coaxial teeth (1, 2), arranged so as to be able to mesh frontally with one another. The teeth of said first and second toothings (1, 2) have faces inclined with respect to an axial plane, and said faces have helical contact surfaces. Thanks to the arrangement of the contact surfaces of the teeth, the triggering of the key is activated very reliably when the tightening torque is reached. The variation between the forces measured during successive trips is small. On the other hand, the wear of the teeth is reduced, which makes it possible to maintain high precision during a prolonged period of use.

Description

Technical area

The present invention relates to a torque tool, in particular, a screwdriver or a torque wrench to trigger. In one embodiment, the torque tool is a watchmaker's screwdriver.

State of the art and problems giving rise to the invention

[0002] Screwdrivers and torque wrenches are used in many technical fields to control the tightening torque of nuts and screws so that they are mounted optimally. These keys can be classified into two main groups. In trigger wrenches, the wrench contains a mechanism that prevents a screw or nut from being tightened with a higher torque than the preset and desired tightening torque. On the other hand, direct read keys display the current value, but do not necessarily contain a trigger mechanism. It should also be mentioned that the trigger wrenches can be fixed value or adjustable.

[0003] Torque tools are disclosed, for example, in patents US 7,272,999, US 7,487,700, US 2007/0281274 and also US 2009/0025851.

[0004] The present invention relates more particularly to trigger torque tools. In order to determine the reliability of such a tool, it is possible to carry out a series of measurements and record the precise value of the tightening torque during a trip. It can then be observed that the screwdrivers that are currently on the market exhibit a greater or lesser variability between the desired tightening torque (fixed or adjusted) and the measured tripping torque. The present inventor has in particular carried out measurements in the field of watchmaker's screwdrivers. An object of the present invention is to reduce the variability between the desired tightening torque and the actual observed tightening torque when using the wrench repeatedly.

Another object of the invention is to reduce the wear of the toothed wheels which are generally used in the trigger mechanism of torque wrenches. The present inventor has found that wear due to repetitive and / or prolonged use of the wrench causes a discrepancy between the adjusted tightening torque and that which is actually observed during the triggering. This discrepancy usually gets larger over time due to wear.

Summary of the Invention

[0006] The present inventor has implemented a dynamometric tool comprising a triggering and / or uncoupling device comprising two toothed wheels and / or two toothings. Generally, the wheels or teeth are coaxial and arranged so as to be able to mesh frontally. Surprisingly, thanks to the shape and / or the contact surfaces of the teeth of these toothings, it is possible to decrease the wear due to repetitive use of the wrench and to decrease the variability between the torque value of desired tightening and that observed.

[0007] In one aspect, the invention relates to a torque tool chosen from among tightening wrenches and screwdrivers, the tool comprising: first and second coaxial teeth, arranged so as to be able to mesh frontally with one another when using the tool; an engagement structure and / or a connection structure making it possible to make the tool integral with said engagement structure, said engagement structure being intended to be brought into contact with a screw, a bolt, and / or a nut during use of the tool, in order to allow the transmission of a rotational moment to said screw, said bolt and / or said nut by said torque tool; a gripping structure, intended to be held in the hand of a user or by a robotic arm and allowing said torque to be applied; a flexible and / or flexible structure, connected to said first toothing so as to exert a determined force on said first toothing and to allow displacement of said first toothing when said first toothing is subjected to a force in the direction opposite to said determined force and when said force in the opposite direction exceeds the value of the determined force.

[0008] In one aspect, the invention relates to the aforementioned torque tool, characterized in that a tooth of said first set of teeth has first and second faces, arranged to be in contact with first and second faces, respectively, of a tooth of said second set of teeth, when the tool is in the position of rest, in that said first and second faces have surfaces inclined with respect to an axial plane, and in that said first faces and / or said second faces have twisted contact surfaces.

Description of the drawings

The characteristics and advantages of the invention will emerge more clearly on reading the description of a preferred embodiment, given solely by way of example, in no way limiting with reference to the schematic figures in which: <tb> <SEP> Figure 1 shows a torque tool in the form of a watchmaker's screwdriver in accordance with one embodiment of the invention. <tb> <SEP> FIG. 2 shows views in elevation of various embodiments of coaxial teeth which can be used to make a torque tool according to one embodiment of the invention. The teeth shown in panels A, B, C are distinguished by the angle between the two contact faces of the teeth and the horizontal (the transverse plane). These angles determine, in combination with an elastic element, the values of the torque for tightening and / or loosening the dynamometric tool. <tb> <SEP> Figure 3 shows the teeth described with respect to Figure 2 in black and white. <tb> <SEP> Figure 4 shows the teeth of Figures 2 and 3 in a front gear position, as is the case when the tool with the teeth is in a rest position or in a position of use when the tightening torque is below the trip or decoupling value. <tb> <SEP> FIG. 5 is a top view in perspective of a first set of teeth of the dynamometric tool according to one embodiment of the invention. <tb> <SEP> Figure 6 is a perspective view showing an enlarged tooth of the set of teeth shown in Figure 5. <tb> <SEP> FIG. 7 is a front view of the teeth according to one embodiment of the invention. <tb> <SEP> FIG. 8 is an enlarged view of an extract from FIG. 6, showing a front view of a tooth of a toothing of the tool according to one embodiment of the invention.

Detailed description of the preferred embodiments

The present invention relates to a torque tool which can be chosen from among tightening wrenches and screwdrivers. In a preferred embodiment, the tool is a watchmaker's screwdriver. In a preferred embodiment, the tool is a trigger wrench or screwdriver.

By way of example, Figure 1 shows a watchmaker's screwdriver 10 according to one embodiment of the invention. The screwdriver 10 has a longitudinal shape and has an outer sleeve 5 comprising an essentially tubular element. The tubular element 5 is closed towards its first end (or its upper end) by a support head 31, produced in the form of a ferrule inserted into the sleeve 5. Towards its opposite end, shown at the bottom in FIG. , the screwdriver includes a connection structure 4.

[0012] The outer sleeve 5 functions as a gripping structure, because it is intended to be held in the hand of a user or by a robotic arm. The sleeve makes it possible to grip the tool and to apply said torque. The user can hold the sleeve 5 by his fingers and apply a torque by rotating the screwdriver axially, around its longitudinal axis.

The connection structure 4 and arranged so as to make it possible to make the screwdriver 10 integral with an engagement structure (not shown). By "engagement structure" is meant any structure having a shape adapted to a particular type of screw or nut, for example slotted head screws, Philips head, Pozidriv cross head, Torx, Tri-Wing, socket head screws, by example. In the case of a torque wrench, the engagement structure is matched to a nut, e.g., hex nut, square nut, to name a few.

The engagement structure can be arranged at the end of a rod, the opposite end of which is adapted to be received by the connection structure 4. The connection structure comprises a housing 34 for the structure of commitment. For these purposes, the connection structure 4 may include an opening 32, adapted to receive the rod of the engagement structure. The side hole 33 is threaded and makes it possible to fix said rod by means of a screw inserted through a second opening 33. In one embodiment, the rod can have a non-circular section, for example square or hexagonal, in order to to be locked in rotation in the connection structure 4.

The elements which allow the screwdriver to perform its function of dynamometer are preferably located inside the tool, for example in the space provided in the tube of the outer sleeve 5. The screwdriver 10 comprises in particular a triggering or uncoupling device 30, which comprises two toothed wheels 41, 42, the teeth of which 1, 2, are arranged so as to be able to mesh with one another.

Before discussing the trigger device, it should be noted that, in the embodiment shown, the first and second toothed wheels 41, 42 are coaxial and arranged so as to be able to mate frontally one in the 'other through their first and second teeth 1, 2, respectively. This type of coupling allows the wheels to be placed in a minimal space. The teeth of these wheels are oriented on a circle in the axial direction, allowing a front gear of the first and second toothed wheels. This type of front gear is also known from the “Hirth toothing”.

[0017] The first and second toothed wheels 41, 42 can themselves be produced in the form of hollow cylinders and / or tubes, housed axially in the housing provided by the outer sleeve 5. The first and second toothed wheels can, for example, be visualized as a tube one of the ends of which is crenellated, said end of the tube thus forming teeth. The first and second toothings 1, 2, in particular the characteristics of the teeth, will be described in detail later below.

In the screwdriver shown in Figure 1, the second toothed wheel 42 is located axially below the first toothed wheel 41. The second toothed wheel 42 thus functions as a lower stop in the axial direction for the first toothed wheel 41 and the retains in its housing in the sleeve 5.

In the trigger device shown, the first toothed wheel 41 is integral in rotation with respect to the sleeve 5, but it can move axially in the sleeve 5, guided by the latter, at least along a predefined distance . The outer sleeve 5 and the first wheel 41 are locked in rotation by mating grooves / ribs.

For example, the first toothed wheel 41 may comprise, on its outer cylindrical surface, longitudinal grooves, in the axial direction, arranged to receive longitudinal ribs, arranged on the inner surface of the sleeve 5, or vice versa.

On the other hand, the second toothed wheel 42 is made integral in rotation with the connection structure 4. In the embodiment shown, the connection structure 4 comprises a rod 36, on which the second tubular wheel 42 is fitted and made integral in rotation by conjugate ribs / grooves. As the second toothed wheel 42 is not made integral in rotation with the sleeve 5, it, as well as the connection structure 4 to which it is integral in rotation, can rotate relative to the outer sleeve 5.

While the assembly formed by the connection structure 4 and the second toothed wheel 42 can, in principle, perform a rotation relative to the sleeve 5, this assembly is blocked in the axial direction. On the other hand, the first toothed wheel can move in the axial direction, but is locked in rotation with respect to the sleeve 5.

The trigger device also comprises the spring 6, which is held in compression between on the one hand the screw 37, and on the other hand the first toothed wheel 41. One end of the spring 6, the lower end according to the Figure 1, rests in particular on a bearing surface 38, disposed at the opposite end of the first toothing 1 on the tube comprising said first toothed wheel 41.

The screw 37, which contains the bearing surface for the upper end of the spring 6, is inserted and retained in the sleeve 5, the latter comprising an internal thread to receive said screw 37. The screw 37 is accessible from the upper opening of the screwdriver, following the removal of the ferrule 31, the latter functioning as a closing plug of the outer sleeve 5.

[0025] The tightening torque of a dynamometric tool corresponds to a determined or predefined value. When the torque applied by a user reaches or exceeds said determined value, the torque is no longer transmitted to the screw, due to the triggering of the release device, more precisely due to a disconnection of the first and second teeth 1, 2.

Those skilled in the art will understand that, in a torque screwdriver as shown in Figure 1, the value of the tightening torque is determined in part by the force exerted by the spring 6 in the axial direction on the first toothed wheel 41, the latter being thus forced into a position of front coupling with the second toothed wheel 42. On the other hand, the value of the tightening torque is determined by the geometry of the contact surfaces of the first and second toothings, as will be described later. below.

When a user tightens a screw using the screwdriver 10, a torque is transmitted from the sleeve, held in the user's hand, through the toothed wheels 41, 42 and meshing, to the connection member 4, and the connection member to the engagement structure and finally to the screw. On the other hand, when the torque applied by the user exceeds the tightening torque, the second wheel 42 rotates relative to the first toothed wheel 41, pushing the latter in the axial direction against the force of the spring 6. This rotational movement between the first and second toothed wheels 41, 42 characterizes the trigger. When the applied torque exceeds the value of the tightening torque, said torque is no longer transmitted to the screw due to the uncoupling, that is to say the relative rotation between the toothed wheels 41, 42.

As mentioned above, the trigger keys can be fixed or adjustable value. According to a preferred embodiment of the invention, the tightening torque of the dynamometric tool is adjustable. In the case of the screwdriver shown in figure 1, the adjustment can be carried out by tightening and unscrewing the screw 37, which determines the axial position of the screw 37 in the sleeve 5. As the screw contains the support for the spring 6, this support position determines the level of compression of the spring 6 and therefore the force exerted by the latter in the axial direction, holding the two toothed wheels in the coupling position. The more the spring is compressed, the greater the torque value of the screwdriver.

It should also be mentioned that the screwdriver shown in Figure 1 comprises a connection member 4, making it possible to make the screwdriver 10 integral with the engagement structure (not shown). As indicated, the engagement structure comprises the part whose shape and / or geometry makes it possible to apply a torque to a screw or a nut and therefore to drive the screw or the nut in rotation in order to tighten and / or loosen it. For example, in a flathead screwdriver, the engagement structure is the flathead that is inserted into the head of a slotted head screw.

In the embodiment shown in Figure 1, the engagement structure can be removed and replaced, for example depending on the screw to be tightened, or when the engagement structure is damaged. In this case, the same screwdriver 10 can be used to tighten different types of screws or screws of different sizes, using the appropriate engagement structure.

In an alternative embodiment of the invention, the engagement structure is integral with the screwdriver and cannot be replaced. In this case, the second toothed wheel can be directly integral in rotation with the engagement structure. In other words, the connection member 4 and the engagement structure can be made in one piece.

The present inventor has found that the precision and reliability of a dynamometric tool depend on the geometry of the teeth of said first and second teeth 1, 2, and in particular on the geometry, shape and / or arrangement of the contact surfaces teeth.

The geometry of the teeth according to the preferred embodiments will be discussed in more detail with reference to Figures 2 to 8. <tb> <SEP> Figures 2 and 3 show three examples of pairs of frontal and axial teeth A, B and C which differ from one another in terms of the shape and / or profile of the teeth of the teeth. By way of illustration, the teeth are shown spaced apart. In Figure 4, the first and second teeth 1, 2 are meshed with one another, as is the case when the tool 10 is at rest or when the tool is used to tighten a screw or a nut, and the torque applied is less than the value of the tightening torque. <tb> <SEP> FIG. 5 is a front perspective view from above of a set of teeth 1, in accordance with one embodiment of the invention. One can clearly see the axial orientation of the teeth 14, arranged at the end of a tube 13. The tube 13 comprising the toothing 1 forms a toothed wheel 41. An annular flange 25 is placed inside the toothing 1. , at the end of the tube 13.

In the case of the second toothed wheel 42, which also contains a flange 25 ', this flange can serve as a bearing surface, for example to retain the toothed wheel 42. As can be seen in Figure 1, the connection member 4 comprises, on its rod 36, an annular bulge 43. This bulge rests on the annular rim 25 ', thus blocking the second toothed wheel 42 axially, preventing upward displacement of the wheel. Towards its lower end, the second toothed wheel 42 rests on an annular edge 44 arranged in the housing of the outer sleeve 5. Thus, the second toothed wheel 42 cannot move axially.

Figure 6 is the extract A of Figure 5, showing in more detail a tooth 14 of the first set of teeth 1. Each tooth has first and second faces or surfaces 11, 12, which are in contact with the faces complementary 11 ', 12' (not shown) of the teeth of the second toothing 2, when the latter is in mesh with the first toothing 1. It should be noted that the first and second teeth 1, 2, are preferably identical, in order to allow an optimal gear. In other words, the teeth of the first set of teeth 1 preferably have the same geometry as the teeth of the second set of teeth 2, at least as regards the contact surfaces, and / or the elements which allow the coupling of the teeth. cogwheels.

In the present description, the expressions "face" and "surface" are used interchangeably to designate the first and second faces 11, 12 of a tooth 14. The term "flank" is also known to designate an area. contact of the tooth of one toothed wheel with another tooth.

In the present description, the prime sign (') is used to refer to a corresponding structural element of the second set of teeth. For example, "the first contact surface 11 of a tooth of the first toothing 1 is in contact with the first contact surface 11 'of the second toothing 2". The structural elements of the second toothing 2 are generally not shown in the drawings, and therefore the corresponding reference numerals (11 ', 12', 25 ') do not appear there.

In a radial direction, perpendicular to the general axis of the toothed wheels 41, 42, each tooth 14 is preferably delimited by the inner and outer surfaces 21, 22. A first contact surface 11 is thus delimited, in the direction radial, by the interior and exterior surfaces. The outer and inner edges 16 and 17 preferably constitute or demarcate this limitation. In the axial direction, the first contact surface 11 is delimited by the top 15 of the tooth. Downwards, the first contact surface 11 can be delimited by a hollow 23, which separates and connects the teeth 14 of a set of teeth.

Similarly, the second contact surface 12, located opposite the first contact surface 11 of the same tooth 14, is delimited, in the radial direction, by the inner and outer surfaces 21, 22, and in axial direction upwards through the top 15, and downwards through a hollow 23 which separates the teeth from the teeth.

In one embodiment, the tooth 14, 14 'of a set of teeth comprises a vertex 15 connecting said first and second faces 11, 12, 11', 12 'of a tooth, said apex 15 being rounded or flattened , preferably rounded. In the case of a flattened top, the tip of the tooth is flat and may have a surface parallel to the transverse (horizontal) plane.

In one embodiment, the surface of the contact face 11, 11 ′ is greater than the surface of said second contact face face 12, 12 ′.

When the first and second teeth 1, 2 are coupled, the first contact surfaces 11 of the teeth 14 of the first teeth 1 are in contact with the first contact surfaces 11 'of the second teeth 2. Similarly, the second contact surfaces 12 of the teeth of the second toothing 2 are in contact with the second contact surfaces 12 'of the first toothing 1. When the first toothed wheel 41 makes a rotation relative to the second toothed wheel 42, the teeth slide on their respective first or second contact surfaces 11, 11 ', 12, 12', depending on the direction of rotation, as shown in Figure 7.

As can be seen in Figures 5 and 6, the contact surfaces 11, 12 are not plane. In one embodiment, at least the first or the second contact surface 11, 12 is not planar, preferably the two contact surfaces of a tooth and / or of the teeth of a set of teeth 1, 2 are not are not level.

[0044] According to a preferred embodiment of the invention, at least one of the two contact surfaces of a tooth of the toothing is helical and / or twisted. The slightly helical and / or twisted surface is shown in Figures 5, 6 and again in Figure 7, in which the arrangement of the first contact surface 11 is recognizable.

[0045] It should be specified, at this stage, that the toothed wheel of the invention does not or does not necessarily have a "helical toothing". In the state of the art, helical teeth include teeth whose shape generator is a helical line with the same axis as the axis of rotation, sometimes reminiscent of the thread of a screw. In this case, they are toothings in which the teeth are oriented essentially in the radial direction and not in the axial direction as is the case according to an embodiment of the present invention. Unlike the helical toothings of the state of the art, the toothing of the present invention is preferably a toothing allowing frontal coupling, in the axial direction, and the contact faces 11, 11 'of the teeth are slightly helical.

The first helical contact surface 11, 11 'is arranged so as to allow the teeth to remain in close contact on the contact surface when one of the toothed wheels rotates relative to the other. The helical surface has the effect of decreasing shear due to rotation, because the surfaces remain parallel, and / or remain complementary during rotation.

At this stage it should be noted that, during a rotation of a toothed wheel relative to the other, one of the two wheels simultaneously performs a movement in the axial direction, in order to allow said rotation when the tightening torque is exceeded. When the contact surfaces between two neighboring teeth are plane, as is the case in known torque screwdrivers, the combination of the two relative movements, the rotation and the concomitant axial displacement, generates locally very high friction forces, for example between a point on the contact surface 11 of a first tooth and a point on the top 15 'of the other tooth, on which the first tooth slides.

According to the invention, a larger portion of the surfaces of two meshed teeth preferably remains in contact during rotation, and consequently the friction effected by a rotating tooth on the contact surface of the other tooth on which it slides, is distributed over a larger area and is therefore more regular. For this reason, wear resulting from high friction at a few points or edges of the teeth of the state of the art is reduced.

Thanks to the arrangement of the contact surfaces of the teeth according to the invention, the triggering of the key is activated very reliably when the tightening torque is reached. The variation between the forces measured during successive trips is small. On the other hand, the wear of the teeth is reduced, which makes it possible to maintain high precision during a prolonged period of use.

In one embodiment of the invention, one of the two contact surfaces of a tooth, for example the second contact surface 12, 12 ', is planar.

A planar surface is chosen, for example, when the contact surface is essentially vertical, that is to say in the plane both radial and axial. Such a plane preferably extends along the axis of rotation 20 (Figures 2 and 5). In this case, the tool 10 has the dynamometric characteristic in one direction of rotation, for example in the tightening direction, but is not dynamometric in the other direction, typically loosening. In many torque tools, a tightening torque applies only to tightening, but not to loosening. This is the case when there is no reason to fear damage to the parts concerned during loosening.

According to a preferred embodiment, the tightening torque is the torque determined in the direction of the watch, and the release torque refers to the torque in the reverse direction.

In another embodiment, the torque tool of the invention comprises a specific and / or limit tightening torque and a specific and / or limit loosening torque. In this case neither of the two contact surfaces 11, 12 of a tooth is vertical / axial, i.e. neither of the two contact surfaces can be aligned in an axial-radial plane. This is a preferred embodiment, shown in the drawings.

In the case of the preferred embodiment, the first and second contact surfaces 11, 12 of a tooth 14 are inclined relative to the transverse plane and also relative to the axial-radial plane. However, according to a preferred embodiment, the tightening torque is different from the loosening torque. Preferably, the loosening torque is higher than the tightening torque. For this reason, the angle of inclination of the first contact surface 11 is different from the angle of inclination of the second contact surface 12.

In the embodiment shown in Figures 5-7, the first contact surface 11 is less inclined, relative to the transverse plane, than the second contact surface 12. The limit torque defined by the second surface 12, combined with the characteristics of the spring 6, will be higher than the limit torque associated with the first contact surface 11. If we consider that the first surface 11 defines (together with the spring 6) the tightening torque and the second surface 12 , the release torque, it becomes clear that the toothed wheel shown in Figure 5 corresponds to the first toothed wheel 41 of the torque screwdriver shown in Figure 1. Figure 5 shows the first toothed wheel 41 in the reverse position with respect to its position in the screwdriver of Figure 1. In Figures 7-8, the first gear 41 is shown in the same orientation as in Figure 1.

A consequence of the helical and / or twisted shape of the first contact surface 11, and preferably also of the second contact surface 12, is that the angle between the contact surface and the transverse plane (horizontal in drawings) does not correspond to a fixed angle value. In order to illustrate the nature of the angles of the contact surfaces, FIG. 8 shows the corresponding straight lines on which the edges of the contact surfaces 11, 12 are located.

FIG. 8 shows a tooth 14 in a front view and / or in elevation from the outside, in the radial direction. The tooth 14 is thus visualized in two dimensions, corresponding to a projection of the tooth 14 on an axial plane or a longitudinal and tangential plane, perpendicular to the radial axis of the observer. In this view, the curve and / or inflection of the inner and outer edges 16-19, coming from the circular section of the toothed wheel, is not visible due to the perspective. In other words, the curvature is eliminated by the choice of the position of the observer of the two-dimensional projection of tooth 14. In this view, the outer edges 16, 18 and inner edges 17, 19 of the first and / or second surface 11, 12 each comprise straight lines and / or segments of a straight line. According to the invention, preferably a part of the aforementioned ridges appears as the segment of a straight line in a view corresponding to that of FIG. 8.

The characteristics of the edges 16-19 described below, for example in terms of angles α, β, γ, δ, apply to the perspective of the tooth 14 according to FIG. 8.

In one embodiment of the invention, for those skilled in the art observing a tooth 14 in front view, in elevation as illustrated in FIG. 8, at least part of the outer edge 16 and / or at at least part of the interior edge 17 of the first contact surface 11 is a segment of a straight line and / or a straight line.

In one embodiment of the invention, for those skilled in the art observing a tooth 14 in front view, in elevation as illustrated in FIG. 8, at least part of the outer edge 18 and / or at at least part of the inner edge 19 of the second contact surface 11 is a segment of a straight line and / or a straight line.

In one embodiment of the invention, the outer edge 16 of said first surface 11, 11 'of said tooth is longer than an inner edge 17 of said first surface 11, 11'. This also applies when said edges are observed in projection as illustrated in Figure 8.

In one embodiment, the outer edge 18 of said second surface 12, 12 'of said tooth is longer than an inner edge 19 of said second surface 12, 12'. This also applies when said edges are observed in projection as illustrated in Figure 8.

As mentioned in Figure 8, the outer edge 16 of the first contact surface 11 appears as the segment of a straight line, the intersection of which with the transverse plane 26 defines the angle α. The inner ridge 17 is on a straight line shown in dotted lines in FIG. 8, which encloses the angle β with respect to the transverse plane 26.

Preferably, the inner and outer edges 16, 17 of the first contact surface 11 are not parallel.

Preferably, the inner and outer edges 18, 19 of the second contact surface 12 are not parallel.

[0066] In the illustrated embodiment, the second contact surface is also helical. For this reason, the outer edge 18 and the transverse plane form between them the angle γ. The angle δ is formed between the inner edge 19 and the transverse plane.

In the context of this description, the angle formed between the first contact surface 11 and the transverse plane 26 is considered to be (α + β) / 2. By analogy, the angle (enclosed) formed between the second contact surface 12 and the transverse plane 26 is considered to be (γ + δ) / 2.

According to one embodiment of the invention, 90 °> α> 5 ° and 90 °> β> 5 °. Preferably 60 °> α> 10 ° and 65 °> β> 15 °, more preferably 55 °> α> 20 ° and 60 °> β> 25 °.

[0069] According to one embodiment of the invention, 90 ° ≥ γ> 10 ° and 90 ° ≥ δ> 10 °. Preferably 70 ° ≥ γ> 15 ° and 75 ° ≥ δ> 20 °, more preferably 65 ° ≥ γ> 20 ° and 70 ° ≥ δ> 25 °.

According to one embodiment, γ> α; and γ, α ≠ 0, that is, γ and α are both, independently of each other, different from 0.

According to one embodiment, δ> β; and δ, β ≠ 0.

According to one embodiment, (γ + δ)> (α + β).

According to one embodiment, α, β> 15 ° (that is to say that each of the two angles is, independently of one another, greater than 15 °), preferably> 20 ° , and more preferably> 25 °, even> 30 °.

[0074] In one embodiment, α + x = γ, x being 5 ° to 40 °, preferably 7 ° to 30 °, more preferably 10 ° to 25 °.

In one embodiment, β + y = δ, y being from 5 ° to 40 °, preferably from 7 ° to 30 °, more preferably from 10 ° to 25 °.

In a preferred embodiment, 15 °> (β-α)> 0, preferably 10 °> (β-α)> 0, and more preferably 6 °> (β-α)> 0.

In one embodiment, 15 °> (δ-γ)> 0, preferably 10 °> (δ-γ)> 0, and more preferably 6 °> (δ-γ)> 0.

In one embodiment, the angle α between the outer edge 16 of said first surface 11, 11 'and a plane 26 perpendicular to the axial direction, is less than the angle β between the inner edge 17 of said first surface 11, 11 'and said perpendicular plane 26.

In one embodiment, angle γ between the outer edge 18 of said second surface 12, 12 'and a plane 26 perpendicular to the axial direction, is less than the angle δ between the inner edge 17 of said second surface 12, 12 'and said perpendicular axis 26.

As those skilled in the art will understand, the difference between the angles α and β is the result (and / or the expression) of the helical surface of the first contact surface 11. Analogously, the difference between the angles y and δ is the result of the helical surface of the second contact surface 12.

Those skilled in the art will be able to choose the angles α, β, γ, δ independently so as to obtain a particular desired result, for example a particular tightening and / or loosening torque, suitable for the application of the torque tool.

Claims (10)

1. Torque tool (10) comprising: - First and second coaxial toothings (1, 2), arranged so as to be able to mesh frontally with one another when using the tool (10); - an engagement structure and / or a connection member (4) making it possible to make the tool (10) integral with said engagement structure, said engagement structure being intended to be brought into contact with a screw, a bolt, and / or a nut when using the tool, in order to allow the transmission of a torque to said screw, said bolt and / or said nut by said torque tool; - a gripping structure (5), intended to be held in the hand of a user or by a robotic arm and making it possible to apply said torque; - a flexible and / or flexible structure (6), connected to said first toothing (1) so as to exert a determined force on said first toothing (1) and to allow displacement of said first toothing (1) when said first toothing is subjected to a force in the direction opposite to said determined force and when said force in the opposite direction exceeds said determined force; characterized in that - a tooth (14) of said first set of teeth (1) comprises first and second faces (11, 12), arranged to be in contact with first and second faces (11 ', 12'), respectively, of a tooth (14 ') of said second toothing (2) when the tool is in the rest position, in that said first and / or second faces (11, 12, 11', 12 ') have surfaces inclined with respect to a axial plane, and in that said first faces (11, 11 ') and / or said second faces (12, 12') have twisted contact surfaces. 2. Tool (1) according to claim 1, characterized in that said teeth (14, 14 ') each comprise a vertex (15) connecting said first and second faces (11, 12, 11', 12 '), said vertices (15) being rounded or flattened, preferably rounded. 3. Tool (10) according to one of the preceding claims, characterized in that, in an elevational view showing said tooth (14) of the first toothing (1) in two dimensions, said elevational view corresponding to a projection of the tooth (14) on an axial plane, perpendicular to the radial axis of an observer, at least part of an outer edge (16) of said first face (11) of said tooth, and / or at least one part of an interior edge (17) of said first face (11), is a segment of a straight line. 4. Tool (10) according to one of the preceding claims, characterized in that an outer edge (16) of said first face (11, 11 ') of said teeth (14, 14') is longer than a stop interior (17) of said first face (11, 11 '). 5. Tool (10) according to claim 3, characterized in that an angle (α) between the segment of the straight line of the outer edge (16) of said first face (11) and a plane (26) perpendicular to the axial direction, is less than the angle (β) between the segment of the straight line of the inner edge (17) of said first face (11) and said perpendicular plane (26). 6. Tool (10) according to one of the preceding claims, characterized in that, in an elevational view showing the tooth (14) of the first toothing (1) in two dimensions, said elevational view corresponding to a projection of the tooth (14) on an axial plane, perpendicular to the radial axis of an observer, at least part of an outer edge (18) of said second face (12) of said tooth, and / or at least one part of an interior edge (119) of said second face (12), is a segment of a straight line. 7. Tool (10) according to claim 6, characterized in that an angle (γ) between the segment of the straight line of the outer edge (18) of said second face (12) and the plane (26) perpendicular to the axial direction, is less than the angle (δ) between the segment of the straight line of the inner edge (17) of said second face (12) and said perpendicular plane (26). 8. Tool (10) according to one of the preceding claims, characterized in that the first face (11) is less inclined, relative to the perpendicular plane (26), than the second face (12). 9. Tool (10) according to one of the preceding claims, said tool being chosen from a tightening wrench and a screwdriver. 10. Tool (10) according to claim 9, said screwdriver being a watchmaker's screwdriver.