FR2680236A1 - Stabilising device for a bow - Google Patents

Abstract

Stabilising device for a bow, of the type comprising two lateral stabilisers made up of two bars (7) forming a V, pointing backwards, on either side of the string. According to the invention, it comprises at least one shock-absorbing system which, including at least one component made of a viscoelastic material, and associated with the two lateral stabilisers, forms a hinge for each lateral stabiliser about an axis substantially parallel to the string when the latter is at rest, allowing favoured oscillation of the lateral stabilisers in a plane perpendicular to the string at rest, damped out by the component or components made of a viscoelastic material.

Description

STABILIZER DEVICE FOR ARC

  The present invention relates to a stabilizing device for an arc.

  Archery competitors have been equipping, for many years,

their stabilizer arcs.

  In a manner known per se, a bow comprises a handle, two branches, and a rope. The rope can be fixed directly to the ends of the branches, or be mounted thereon by a set of pulleys. In the latter

  case, it is about an arc known under the name of "Compound".

  A stabilizer aims to: increase the inertia of the entire arc perpendicular to the plane containing the handle and the rope, at the time of aiming, increase the inertia in rotation around a vertical axis passing through the handle the bow, position the center of gravity in front of the point of contact of the hand on the handle, so that the upper branch of the bow tips over

the front and not the rear.

  In addition to these stabilization functions proper, a stabilizer also aims to absorb parasitic vibrations due to the shock of the branches

at the time of the arrow's departure.

  In summary, a stabilizer aims on the one hand to modify the inertia of the arc, and on the other hand, to absorb vibrations in order to improve comfort

shooting.

  There are different types of stabilizers which are often used in combination. A first stabilizer is a central stabilizer, consisting

  by a branch projecting longitudinally towards the front of the arch.

  Lateral stabilization is obtained using two V-shaped arms,

  facing backwards on either side of the rope.

  It is also possible to combine central stabilization with frontal stabilization using two other branches also facing forwards and situated above and below the aforementioned central branch. These different branches intended to achieve stabilization can be fixed indifferently on several points provided for in this

  effect provided on the handle of the bow.

  The stabilizers were successively made of thin steel tubes with a high modulus of elasticity, then they were made

  aluminum, and are now made of composite material.

  The known devices have the drawback of being very complex to implement, since comprising a very high number of parts. They include in particular a body intended to be fixed on the handle of the bow, on which the various bars are fixed, with interposition, for the lateral stabilizers of parts making it possible to adjust the angle that forms each branch with the plane passing through the handle and the rope On the other hand, in order to modify the inertia, it is possible to mount on each bar of the modular weights, i.e. each made up of several elements capable of being screwed on top of each other to obtain the desired total mass If, there are damping elements at the level of the mounting parts of each lateral stabilization bar on the body, these parts are made of very high hardness materials to allow their

  machining, which only allows infinitely small deflections.

  In addition to the complexity of the known stabilizers, which consist of a large number of parts which have to be handled during each mounting or each dismantling of the stabilizer, these provide, taking into account the rigidity, only low damping. been proven that this damping was extremely low in the frequency band between 20 and 150 hertz which is precisely the frequency range

  in which it would be most useful to dampen vibrations.

  The object of the invention is to remedy these drawbacks by providing a stabilizing device for an arc, which is of simple design, that is to say in which the number of parts is reduced, with the possibility of modifying the inertia. without adding or removing weight and capable of damping vibrations, especially those in the range of 20 to

150 Hz.

  To this end, the device it relates to, of the type comprising two lateral stabilizers constituted by two bars forming a V, oriented towards the rear, on either side of the rope, is characterized in that it comprises at at least one damping system which, comprising at least one piece of visco-elastic material, and associated with the two lateral stabilizers, hinge shape for each lateral stabilizer along an axis substantially parallel to the rope when the latter is at rest, allowing a privileged oscillation lateral stabilizers in a plane perpendicular to the rope at rest, damped by the piece or pieces of material

visco-elastic.

  Therefore, during the shock resulting from the start of the boom, the two branches of the lateral stabilizers are capable of pivoting backwards then, pivoting forward, this oscillation induced by the inertia of the masses carried by the two branches lateral stabilizers being absorbed by the specific characteristics of the elastomer constituting the visco-elastic material. Such a stabilizing device makes it possible to absorb approximately twice as much vibration in the range between 20 and 150 hertz, which increases

  considerably the comfort of the shooting and consequently the precision.

  According to a first embodiment, this device comprises a piece of visco-elastic material fixed in its central part to the handle, protruding laterally on either side of the latter and on the lateral parts of which are fixed the ends of the two branches

  belonging to the lateral stabilizers.

  Each branch of a lateral stabilizer is fixedly mounted on the piece of visco-elastic material, and it is this which is deformed relative to its central part to create the oscillation movement of the stabilizing bars. Advantageously, each branch belonging to a lateral stabilizer is mounted on the piece of visco-elastic material by means of an axis perpendicular to the plane containing the two branches,

  on which it is adjustable in rotation.

  Even if each branch is rigidly mounted under conditions of use of the piece of visco-elastic material, it is possible to adjust

  its initial angle to adapt it to the user's choice.

  According to a characteristic of the invention, this device comprises a rigid centering piece disposed between the handle of the arc and the piece of visco-elastic material, comprising a front face having a central zone perpendicular to the plane of the arc extended by two surfaces inclined towards the rear and forming stops for the branch support part,

  during its deformation.

  This rigid centering piece also forms a stop to limit

  possibly the oscillation of the branches, after sending an arrow.

  In accordance with another embodiment, this device comprises a support for lateral stabilizers comprising a rigid central part connected by two legs of visco-elastic material forming hinges to the two end fittings for the branches. In this case, it is flexibility. legs in visco-elastic material which ensures the oscillation of the two stabilizing bars. According to another embodiment, this device comprises a support for lateral stabilizers comprising a rigid central part on which the rigid end pieces of the two branches are freely mounted articulated around axes perpendicular to the plane of the two branches, each articulation being embedded in a mass of visco-elastic material. The viscoelastic material which surrounds each joint limits the oscillation movement of the branch associated with this joint, and

dampens this movement.

  Advantageously, this device further comprises a central shock absorber which, mounted between the handle and the lateral stabilizers, has a tubular piece, made of a visco-elastic material, intended to be traversed longitudinally by a rod for fixing the entire device on the handle of the bow, and on the ends of which are mounted two flanges intended to bear respectively on the handle of the bow and on a rigid centering piece used for mounting the branches

  central and lateral stabilizers.

  According to another advantageous characteristic of the invention, each branch belonging to a stabilizer is equipped with a counterweight comprising a first cylindrical part having an internally threaded end extended by a conical recess, and into which a second cylindrical part intended to come is screwed bear against a ring of conical section, engaged in the conical recess of the

first part.

  It is thus possible, by simply unscrewing the second part of the cylinder, to decompress the conical ring, to obtain a free sliding of the assembly on the bar before new locking in the desired position. This makes it possible to optimally adjust the inertia specific to each stabilizer without requiring the addition or removal of weight, and this

  in an easy way without the use of any tool.

  In any case, the invention will be well understood using the

  description which follows with reference to the attached schematic drawings

  representing by way of nonlimiting example, an embodiment of this

stabilizing device.

  Figure l is a perspective view of an arc equipped with this device Figure 2 is a front view of the device, on the side of the branches of the lateral stabilizer; Figure 3 is a top view, partially in section, one of the branches being folded down; Figure 4 is a very schematic top view of this device

  showing the oscillations of the branches of the lateral stabilizer.

  FIG. 1 represents an arc 2 comprising a handle 3 on which are mounted two branches 4 at the free ends of which a rope is fixed 5 This arc is equipped with a stabilizing device comprising a branch 6 directed towards the front belonging to the central stabilizer, And two

  branches 7 belonging to the lateral stabilizer.

  The stabilizer according to the invention, shown in more detail in Figures 2 and 3, comprises a central damper 8 consisting of a tubular piece 9 made of a visco-elastic material, intended to be traversed longitudinally by the rod 10 for fixing on the handle of the bow, and on the ends of which are fixed two flanges 12 and 13 intended respectively to bear on the handle of the bow, and to bear

  on a rigid part 14 used for mounting the lateral stabilizer.

  This part 14 comprises a front face having a central part 15 perpendicular to the plane of the arc, and two lateral surfaces 16 inclined towards the rear. On the part 14 is fixed a part 17 of visco-elastic material, the central part of which takes bearing against part 15 of part 14, and the two lateral parts of which, projecting on either side of the handle, form two yokes 18 each serving for mounting an axis 19 allowing the attachment of a nozzle 20 d 'a branch 7 of a lateral stabilizer If each branch 7 can be adjusted around the axis 19, it is blocked with respect to the part 17 made of visco-elastic material, under the use of the arc A l 'before the part 17 in visco-elastic material,

  is mounted branch 6 belonging to the central stabilizer.

  On each of the branches 6 or 7 is mounted a counterweight 22 comprising a first cylindrical part 23, sliding on the branch, having an internal thread 24 allowing the screwing of a second cylindrical part 25 The internal thread 24 is extended on the side of the inside of the first cylindrical part 23 by a conical recess, serving to accommodate a conical ring 26 When the part 25 is tightened, the conical ring 26 under the effect of the stress which it receives, is deformed and used on the branch 6 or 7, ensuring the axial locking of the counterweight on this branch It is thus very simple, by unscrewing the second cylindrical part 25 to unlock the ring 26, to achieve a suitable positioning of the counterweight in order to provide to the stabilizer

considered inertia desirable.

  FIG. 4 represents the stabilizer in three positions At rest, the two lateral stabilizers are in the TO position When the arrow starts, the shock suffered by the handle is transmitted to the lateral stabilizers whose branches come closer to occupy the position TI From this position TI the branches oscillate until in position T 2, this oscillation being damped thanks to the nature of the part 17

  which is made of visco-elastic material.

  It is thus possible to obtain an excellent damping of the vibrations, while giving the arc the desired inertia, and by putting in

  works a limited number of pieces of simple design.

  It goes without saying that the invention is not limited to the sole embodiment of this arc and of its stabilizer described above by way of

  for example, it embraces on the contrary all the variant embodiments.

  Thus, in particular that the lateral stabilizers could be mounted on rigid parts articulated around real axes, coated in visco-elastic material, that the connection between the central support of the lateral stabilizers and the latter could be achieved by intermediate legs of a visco-elastic material or that the device may not include a central stabilizer, without that

  so far from the scope of the invention.

Claims (7)

  1 stabilizing device for an arc, of the type comprising two lateral stabilizers constituted by two bars (7) forming a V, oriented towards the rear, on either side of the string, characterized in that it comprises at least one system shock absorber which, comprising at least one piece of visco-elastic material, and associated with the two lateral stabilizers, forms a hinge for each lateral stabilizer along an axis substantially parallel to the rope when the latter is at rest, allowing a privileged oscillation of the lateral stabilizers in a plane perpendicular to the rope   at rest, damped by the piece or pieces of visco-elastic material.   2 Device according to claim 1, characterized in that it comprises a piece (17) of visco-elastic material fixed in its central part on the handle (3), projecting laterally on either side of it and on the parts side of which are fixed the ends of the two branches (7)   belonging to the lateral stabilizers.   3 Device according to claim 2, characterized in that each branch (7) belonging to a lateral stabilizer is mounted on the part in a visco-elastic material by means of a perpendicular axis (19)   to the plane containing the two branches, on which it is adjustable in rotation.   4 Device according to claim 2, characterized in that it comprises a rigid centering piece (14) disposed between the handle of the bow and the piece (17) of visco-elastic material, comprising a front face (15) having a central zone perpendicular to the plane of the arc extended by two surfaces (16) inclined towards the rear and forming stops for the part   support of the branches, during the deformation thereof.   Device according to claim 1, characterized in that it comprises a support for lateral stabilizers comprising a rigid central part connected by two tabs of visco-elastic material forming hinges to the   two end fittings for the branches.   6 Device according to claim 1, characterized in that it comprises a support for lateral stabilizers comprising a rigid central part on which are mounted freely articulated the rigid end pieces of the two branches around axes perpendicular to the plane of the two branches, each   articulation being embedded in a mass of visco-elastic material.   7 Device according to any one of claims 1 to 6,   characterized in that it further comprises a central shock absorber (8) which, mounted between the handle and the lateral stabilizers, has a tubular part (9), made of a visco-elastic material, intended to be traversed longitudinally by a rod fixing (10) of the entire device on the handle (3) of the arch, and on the ends of which are mounted two flanges (12,13) intended to bear respectively on the handle (3) of the arc and on a rigid centering piece (14) used for   mounting the arms of the central and lateral stabilizers.   8 Device according to any one of claims 1 to 7,   characterized in that each branch belonging to a stabilizer is equipped with a counterweight (22) comprising a first cylindrical part (23) having an internally threaded end (24) extended by a conical recess, and into which a second cylindrical part is screwed (25) intended to come to bear against a ring (26) of conical section,   engaged in the conical recess of the first part.