WO2009112902A1

WO2009112902A1 - Device for launching a bolt or a launch object in general

Info

Publication number: WO2009112902A1
Application number: PCT/IB2008/054053
Authority: WO
Inventors: Pasquale Stanziale
Original assignee: Nec Plus Ultra S.R.L.
Priority date: 2008-03-10
Filing date: 2008-10-03
Publication date: 2009-09-17
Also published as: US20110041820A1; WO2009113018A1; ITRM20080130A1; CN102027310A; CN102027311A

Abstract

A device (1; 70; 71; 72; 73; 74; 80) for launching a bolt, comprising: a stock (2); at least two bending members (10) associated to said stock (2) on opposite sides of it; tensioning means (20) of said bending members (10), comprising at least two cams (21; 81; 161; 171) arranged on opposite sides of the stock (2), each of which is pivoted at a respective first axis of rotation (22) and is associated to at least one corresponding bending member (10); pushing means (30) of said bolt apt to cooperate with said bending members (10), comprising at least two arms (32; 84; 132; 142) arranged on opposite sides of the stock (2) and connected to each other through a flexible member (31), wherein each of said arms (32; 84; 132; 142) has a first end pivoted at a second axis of rotation (33) and a second end (34; 143) apt to support a portion of said flexible member (31), each of said arms (32; 84; 132; 142) being operatively connected to a respective cam (21; 81; 161; 171).

Description

DEVICE FOR LAUNCHING A BOLT OR A LAUNCH OBJECT IN GENERAL

DESCRIPTION

This invention refers to a device for launching a bolt or a launch object in general. More specifically, it refers to a perfected type of archery crossbow.

Various types of devices for launching bolts are already known, both for sports and amateur uses, and for professional uses. Among these, we can identify, in particular, crossbows, generally consisting of a bow (in wood, metal, or plastic or composite material, e.g. including glass or carbon fiber) apt to accumulate elastic energy to return it to the bolt to be launched, a propulsive cable for pushing the bolt, a fastening system to keep said cable in the load position and then release it, a stock secured at one end to said bow and comprising a support-guide for the bolt. The modern devices for launching a bolt usually have a bow divided into two bending members (also called limbs) which are identical (left and right) and secured to a central handle member or to an end of a stock of the device.

In certain embodiments (e.g. US 3,854,467; US 3,923,035; US 20 3,987,777), there are pulleys pivoted to the free ends of the bending members and pulleys pivoted to a central member; the pulleys include tracks on which a propulsive cable is partially wound, which connects the end of one bending member to the end of the opposite member. At least some of the pulleys have an eccentric profile.

The traction of the propulsive cable turns the pulleys, unwinding therefrom, and, at the same time, winding the propulsive cable around the same pulleys; this causes the bending of the bending members and the accumulation of elastic energy. Thanks to an adequate profiling of the pulley tracks and an appropriate eccentricity of the same, in these devices it is possible to reduce the maximum force which must be exercised by the user during the loading of the device and increase the ratio between the stroke of the bolt (also called "draw length") and the movement of the end of the bending members. Other embodiments of devices for the launching of bolts comprising pulleys or similar for a similar purpose are disclosed, for example, in US 5,388,564, US 5,499,618, US 5,967,132.

Embodiments of a crossbow comprising pulleys are disclosed, for example, in US 5,630,405 and US 6,155,243. One of the main disadvantages of the devices of known art and, in particular, of crossbows of known art, is that during the launch phase, the bending members, the propulsive cable and any pulleys arrive at the end of the stroke with a high residual kinetic energy, proportional to the masses in movement; because of the very structure _ .

of the device, this energy must be dissipated in a very short space or even no space, as the components in motion have already reached the end of their possible stroke. The stopping of the components in motion after the launch is, therefore, quite sudden and subjects the entire device to an end of stroke shock which involves very high stresses, discharging the residual energy on the cables and stressing the pivots of the pulleys and the bending members. Indeed, in the case of dry firing (that is, no bolt is fired), there is no transfer of energy to a free mass and the stresses may be so high as to break the device. This dictates structural constraints in the dimensioning of the device, imposes practical limits on the mass that can be launched safely and imposes very high levels of attention and expertise on the part of the user who, in case of dry firing or of using too light a bolt, could damage the crossbow or even get injured. In the case of said more advanced devices, the problem is actually accentuated by the presence of the pulleys at the ends of the bending members, as this considerably increases the masses, the kinetic energy and the moments of inertia in play. In addition, the sudden stop at the end of the stroke is the main cause of the noise produced by the use of a device for launching a bolt.

Another disadvantage of the devices of known art is the fact that, even when the device is unloaded, the bending members are in a pre-tensioned state; among other things, this makes it necessary to use specific tools, such as a press, in order to carry out maintenance operations such as the replacement of the propulsive cable. Finally, it must be noted that possible differences, even slight ones, in the elastic characteristics of the right and left bending member may be the cause of asymmetries in the thrust exercised on the bolt and, therefore, compromise the launch precision. On the other hand, not even the pulleys manage to compensate for any such differences in the elastic characteristics of the bending members. Also note that the crossbows of known art usually take the form of a device which allows little or no possibility of adapting to the requirements of the user: once a crossbow of known art has been built to certain specifications, the maximum power or the force required for the loading are substantially fixed and can no longer be varied, except with laborious replacements of components which, in any case, are beyond the common user. These interventions, in fact, are dangerous and also void the warranty provided by the manufacturer. This invention, therefore, starts from the position of the technical problem of providing a device for launching a bolt or a launch object in general which makes it possible to overcome the disadvantages specified above with reference to the known art. _ _

As defined in independent claim 1, this is obtained by providing a device for launching a bolt or a launch object in general, comprising: a stock having a longitudinal development direction between a rear or proximal end and a front or distal end, at least two bending members associated to said stock on opposite sides of it and having a preferential development direction, said bending members being apt to be subjected to bending in order to accumulate and supply energy usable to launch said bolt, and released in a rest condition, tensioning means of said bending members, pushing means of said bolt apt to cooperate with said bending members, wherein said tensioning means comprise at least two cams arranged on opposite sides to the stock, each of which is pivoted at a respective first axis of rotation and is associated to at least one corresponding bending member, so that an angular displacement of said cam around said first axis of rotation determines a bending action on said at least one corresponding bending member, and said pushing means comprise at least two arms arranged on opposite sides of the stock and connected to each other through a flexible member, wherein each of said arms has a first end pivoted at a second axis of rotation and a second end apt to support a portion of said flexible member, each of said arms being operatively connected to a respective cam, so that a rotation of each arm in a first rotation direction determines a bending of said bending members by means of the cam during a loading phase of the device and that during a launch phase of said bolt a return of the bending members towards said rest condition determines, by means of the cam, a rotation in the opposite direction of each arm.

Secondary characteristics of this invention are defined in the corresponding dependent claims. This invention provides certain significant advantages. The main advantage is the fact that the invention device permits a reduction in the stresses acting on the structure in the end of the stroke arrest, thanks to the absorption of the inertia of the parts in movement, with consequent better performance and higher safety levels for the user. A second advantage consists of the fact that the invention device makes it possible to compensate for asymmetries between the force exercised by the left and right bending member; this determines a uniform distribution of the force acting on the bolt during the launch phase, even in the presence of asymmetries in the elastic characteristics of the bending members, which benefits the launch precision. A third advantage consists of the fact that the invention device makes it possible to vary the specific use characteristics (maximum power, force-traction curve, maximum force required for the loading...) and simpler maintenance. _ _

Another advantage consists of the fact that the invention device makes it possible to increase, with respect to the known art, the ratio between the stroke of the bolt and the extent of the movement of the masses of the bending members, thereby increasing the efficiency of the conversion between potential and kinetic energy. In one embodiment, the bending members are arranged so that their preferential development direction is substantially parallel to the longitudinal development direction of the stock. This benefits the compactness of the device, reducing the lateral dimensions. Preferably, the bending members are positioned close to the stock. In one embodiment, the bending members, the cams and the arms are arranged in a manner substantially symmetrical with respect to the stock. This configuration is advantageous as the symmetrical arrangement favors a symmetrical and balanced distribution of the forces acting on the stock and the elimination of the residual forces acting on the stock itself, which in this way, is subject to less stresses which could damage it.

In one embodiment, the axes of rotation of the cams move together with a portion of at least one bending member, in a direction orthogonal to the development direction of the bending member. This movement takes place at the same time as the rotation of the cam, thanks to the fact that the cam has an eccentric profile which cooperates with a respective cam positioned symmetrically. This makes it possible to load the device by means of a rotation of the cams around their axes of rotation and launch the bolt with a rotation movement in the opposite direction.

More specifically, the cams are pivoted using a connection element which comprises at least one "U"-shaped or "C"-shaped housing which houses a portion of the respective bending member.

In one embodiment, the movement of each cam is synchronized with a respective cam positioned symmetrically with respect to the stock. This allows for a uniform distribution of the force acting on the bolt during the launch phase, even in the presence of asymmetries in the elastic characteristics of the bending members, and also makes it possible to eliminate the components of the acting force which are orthogonal to the launch direction; this benefits the launch precision. In one embodiment, the cams have an edge with teeth, so that each cam can engage the respective symmetrical cam by means of these teeth. This makes it possible to synchronize the movement of each cam with the respective symmetrical cam. In one embodiment, there is a slide positioned between one cam and the respective symmetrical cam; said slide may slide in the device stock in a direction parallel to the longitudinal development direction of the stock and is engaged by the edges of the _ _

cams. In this way, the motion of the cams is synchronized thanks to the fact that they both engage the slide and make it slide along the stock.

To be more specific, the slide may have toothed edges in order to engage the toothing of the cams. Alternatively, the synchronization between the cams is obtained by hinging together one cam and the respective symmetrical cam, which are pivoted to each other using a pivot body which is slidingly associated to the stock and may slide within it parallel to its longitudinal development direction. In one embodiment, each arm forms a single part with a respective cam and the axis of rotation of the arm is the same as the axis of rotation of the respective cam. This solution has the particular advantage of requiring a lower number of parts and being of simpler construction.

In one embodiment, each arm is operatively connected to a respective cam using at least one connection rod pivoted to the arm and to the cam. This solution makes it possible to reduce the maximum lateral dimensions of the device and allows for greater design flexibility.

In one embodiment, each arm is operatively connected to a respective cam using a guide member (for example, a rotating wheel) joined to the arm and which engages slidingly a guide track provided in an appendix of said cam. This solution allows, for same lateral dimensions, higher device power and a longer stroke for the flexible member.

In one embodiment, the second end of each arm supports a pulley rotationally associated to the respective arm; said pulley rotates around an axis of rotation which, therefore, performs translation movements together with the second end of the respective arm; the pulley is further apt to wind on to itself at least partially the flexible member during a rotation movement around its axis. Preferably, the pulley has an eccentric profile with respect to said axis of rotation.

Even more preferably, the rotation of the pulley is synchronized with the rotation of a respective cam around the respective axis of rotation. More specifically, the pulley includes a pivot integral to it and having a longitudinal axis which is coincident to said axis of rotation of the pulley; said pivot also includes at least one toothed portion; the respective cam is firmly joined to at least one appendix having a guide track, said guide track comprising an edge with toothing apt to be engaged by said toothed portion of said pivot. These solutions presenting a pulley supported at the end of each arm offer a first advantage consisting of not leaving the flexible member slack at the end of the launch. In addition, the possibility of selecting the eccentricity of the pulley, the _ _

magnitude of the angle of rotation of the pulley, and an opportune dimensioning and relative positioning of the parts makes it possible to obtain various different force- traction curves. A further advantage is the cancelling out of the residual forces acting on the device and of the inertia of the pulleys, thanks to the movement of these in opposite directions.

In one embodiment, the arms may rotate between a first position of maximum loading towards the proximal end of the stock and a second position of maximum discharge towards the distal end of the stock. Between said first and second positions, there is a neutral position at which the bending members do not present accumulated elastic energy.

To be more specific, said second position corresponds to the maximum advance of the arms towards the distal end, in the braking stroke after the launch stroke, where with launch stroke it is meant the run of the arms between said first position of maximum loading and said neutral position, while with braking stroke it is meant the run of the arms between said neutral position and said second maximum discharge position.

Therefore, with the device loaded, the bending members are initially in a bent configuration; during the launch phase, the bending members reduce the bending gradually, they pass the rest position (corresponding to said neutral position) and continue their movement by bending in the opposite direction, until they get to a configuration of maximum counter bend corresponding to said second position of maximum discharge. One advantage of this solution is that it allows for a gradual and non-sudden stopping of the components at the end of the launch phase, thereby reducing the stresses at the end of the stroke and the risk of damaging the device. Contrast means operating when the arms are between the neutral position and the position of maximum discharge may also be provided.

In addition or in alternative to the contrast means, the device may include auxiliary pushing means including at least one elastic member apt to accumulate energy during the device loading phase and apt to supply energy to the pushing means during the bolt launch phase. This makes it possible to increase the power of the device for same overall dimensions.

Further advantages, characteristics and the modes of employment of this invention will become apparent from the following detailed descriptions of preferred embodiments thereof, presented for exemplificative and not limitative purposes. It is however evident that each embodiment described in this disclosure may present one or more of the advantages listed above; in any case, it is not required that each embodiment presents at the same time all the advantages listed. _ _

Reference will be made to the figures of the drawings attached, in which:

- Figure 1 shows a plan view of an embodiment of a crossbow according to the known art;

- Figure 2A shows a perspective view of a first embodiment of a device for launching a bolt according to this invention;

- Figure 2B shows a perspective view of the device in Figure 2 A, in which different operative positions are shown;

- Figure 3 shows an enlarged detail of the device in Figure 2 A in a loading phase;

- Figure 3 A shows a further enlarged detail of the device in Figure 2 A; - Figure 4 shows again a detail of the device in Figure 2 A in a launch phase;

- Figure 5 shows a construction detail of the device in Figure 2 A;

- Figure 6 shows a perspective view of a component of the device in Figure 2 A;

- Figure 7 shows an exploded perspective view of another component of the device in Figure 2A; - Figure 8 shows a perspective view of a second embodiment of a device for launching a bolt according to this invention.

- Figure 8 A shows a construction detail of the device in Figure 8, from which some components have been removed;

- Figure 9A shows a perspective view of a third embodiment of a device for launching a bolt according to this invention;

- Figure 9B shows a perspective view of the device in Figure 9 A, in which a different operative position is shown;

- Figure 10 shows a perspective view of the device in Figure 9 A, from which some components have been removed; - Figure HA shows a perspective view of a fourth embodiment of a device for launching a bolt according to this invention;

- Figure HB shows a perspective view of the device in Figure HA, in a different operative position;

- Figure HC shows a plan view from below of the device in Figure HA, from which some components have been removed, in a further operative position;

- Figure 1 ID shows a perspective view of an enlarged detail of the device in Figure 1 IA₅ from which some components have been removed;

- Figure 12A shows a perspective view of a fifth embodiment of a device for launching a bolt according to this invention, in a first operative position; - Figure 12B shows a perspective view of the device in Figure 12 A, in a second operative position;

- Figure 12C shows a plan view of the device in Figure 12 A, in a third operative _ _

position;

- Figure 13 shows a perspective view, partially in cross-section, of an enlarged detail of the device in Figure 12 A, from which some components have been removed; - Figure 14 A shows a perspective view of a sixth embodiment of a device for launching a bolt according to this invention, in a first operative position;

- Figure 14B shows a perspective view of the device in Figure 14 A, in a second operative position;

- Figure 14C shows a perspective view of the device in Figure 14 A, in a third operative position;

- Figure 15 shows a perspective view, partially in cross-section, of an enlarged detail of the device in Figure 14 A, from which some components have been removed;

- Figure 16 shows a side perspective view of an enlarged detail of the device in Figure 14 A;

- Figure 17A shows a perspective view of a seventh embodiment of a device for launching a bolt according to this invention, in a first operative position;

- Figure 17B shows a perspective view of the device in Figure 17 A, in a second operative position; and - Figure 17C shows a perspective view of the device in Figure 17 A, in a third operative position.

An embodiment of an archery crossbow 1001 according to the known art (US 6,155,243) is shown in Figure 1. It has a stock 1002 with a butt 1003, bending members 1010 connected to said stock 1002, a propulsive cable 1031 for pushing a bolt, a fasten and release system (not shown, but located near the butt 1003) for said propulsive cable 1031, a shooting trigger (not shown). The free ends of the bending members 1010 support eccentric pulleys 1009, so that the propulsive cable 1031 passes at these and connects them to the bending member opposite. During the loading phase, shown in Figure 1, the propulsive cable 1031 is drawn towards the butt 1003, causing the eccentric rotation of the pulleys 1009, the bending of the bending members 1010 and the accumulation of elastic energy in these. During the launch phase, the same movements take place in the opposite direction, with the transfer of energy to a bolt (not shown) which slides in a suitable guide track 1008. This type of known-art crossbow 1001 has the disadvantages mentioned above. A first embodiment of a device for launching a bolt or a launch object in general, created according to this invention, is shown in Figures 2A to 7, where it is indicated with the reference number 1. Hereinafter in the description, particular reference will _ _

be made to an archery crossbow, although the same principles of the invention could similarly be applied to other launch devices, such as for example a bow or a catapult. The crossbow 1 comprises a stock 2 with a longitudinal development direction 201, comprised between a rear or proximal end 205 and a front or distal end 206. The other components are connected to the stock 2. The portion of the stock 2 which is closest to a user during use, that is, the rear or proximal end 205, comprises, in fact, a butt 3, a handle 4, a system 5 for positioning and holding a bolt or an arrow (not shown in the figures), a system 6 for fastening a flexible member 31 for pushing a bolt, a trigger 7 which makes it possible to open the fastening system 6 in order to release the flexible member 31 when launching the bolt. The components listed so far can be considered to be substantially known-art components and, therefore, will not be described in greater detail.

The crossbow 1 also comprises at least two bending members 10, which have an elongated shape along a preferential development direction 202, for example, with a parallelepiped shape. They may be made of wood, metal, fiberglass, plastic or composite material, e.g. including glass or carbon fiber, or other suitable material. The bending members 10, from the structural and functional point of view, may be considered to be substantially identical to the bending members used in known-art crossbows. The bending members 10 are suitable for being subjected to bending in order to accumulate the elastic energy required to launch the bolt and to supply it subsequently during the launch itself. At the end of the launch of the bolt, the bending members 10 are released in a rest condition. In the embodiment represented here, the bending members 10 are positioned substantially adjacent to the stock 2 and in a symmetrical manner with respect to it, so that their preferential development direction 202 is substantially parallel to said longitudinal development direction 201 of the stock 2 itself; to be more specific, there are four bending members 10, as there are two on each side of the stock 2. The bending members 10 are associated to the stock 2 on opposite sides of it. To be more specific, the bending members 10 are connected and/or may be connected (in other words, associated) to the stock 2 using supports 11 positioned at the ends 101, 102 of the bending members 10. Said supports 11 are pivoted to the stock 2 and have a housing 12 substantially with a "C"-shape which houses said end, in any case allowing the bending member 10 a limited translation movement along said preferential development direction 202; the bending member 10 can, in fact, slide in said housing 12 along that direction. This is beneficial during the loading phase of the bending members 10, as it allows them to take on a simply arched shape, _ _

preventing the creation of longitudinal stresses. In addition, the bending members 10 may be removable, said supports 11 being made so as to allow the extraction of the bending members 10 when it is necessary to replace them.

The bending members 10 might, however, have said support 11 only at one end, while the other end might be constrained in a rigid manner to the stock 2. They might also be secured with different methods, e.g. using a ring cable which surrounds and tightens a bending member 10 and its corresponding bending member on the other side of the stock 2; this solution will be illustrated below. Alternatively, each end 101, 102 of a bending member 10 is closed off at the side between a first sidebar, e.g. with a cylindrical shape, constrained to the stock 2 and a second sidebar, e.g. a support which is preferably cylindrical, positioned outside the bending member 10 with respect to the stock 2, as illustrated in figures HA to 11D for another embodiment. As an alternative, at least one portion of a bending member 10 might be constrained in a rigid manner to the stock 2.

It is also possible to combine these methods to associate a bending member 10 to the stock 2; for example, a bending member 10 could include a first end constrained using said support 11 and a second end constrained using said cylindrical sidebars. Similarly, different bending members 10 may have different association methods. The crossbow 1 comprises tensioning means 20 for said bending members 10, that is, means apt to bring them to a bent position during said loading phase. The tensioning means 20 comprise at least two cams 21 positioned in opposite sides of the stock 2, symmetrical with respect to said stock 2. Each cam 21 is pivoted at a respective first axis of rotation 22 and is associated to at least one corresponding bending member 10, so that an angular displacement of the cam 21 around said first axis 22 creates a bending action on the corresponding one or more bending members 10. In the embodiment illustrated, the overall structure is such that each side of the stock 2 has at least two bending members 10 opposite to each other with respect to a plane on which the cams 21 lie and on which their rotation movement takes place, in order to create, overall, a group of at least four bending members 10 symmetrical with respect to the longitudinal development direction 201 of the stock 2. The cams 21 have an edge 23 having an eccentric profile with respect to said first axis of rotation 22, said edge 23 also having, at least partially, a toothing 24. In addition, there is a slide 25 associated to the stock 2 and positioned between the cams 21.

Said slide 25 has a substantially elongated shape and has toothed edges 26, by means of which it is in engagement on opposite sides with the teeth 24 of the cams 21. The _ _

slide 25 slides in the stock 2 substantially parallel to said longitudinal development direction 201 and, during said sliding movement, coordinates the angular displacement of the cams 21. In addition, the slide 25 can be removed from the stock 2. The crossbow 1 also comprises connection elements 27 between cams 21 and bending members 10. Each connection element 27 comprises at least one connection member apt to move a portion of a bending member 10. To be more specific, said connection member includes a housing 28 substantially "U"-shaped or "C"-shaped apt to house said portion of bending member 10; the connection element 27 also comprises a cylindrical collar 29.

In this embodiment, each bending member 10 is fixed with respect to the corresponding connection element 27, that is, a translation movement of the connection element 27 with respect to the bending member 10 along its preferential development direction 202 is prevented; the connection element 27 and the bending member 10, therefore, move together.

The connection element 27 represented in figure 3 A comprises two of said connection members, each with a "U"-shaped housing 28, positioned symmetrically with respect to a plane and connected to each other by said cylindrical collar 29; this connection element 27 is, therefore, apt to be associated with two bending members 10 and each of said connection members is apt to move a portion of a respective bending member 10.

There are suitable guides for limiting the movements of the connection element 27 with respect to the stock 2. To be more specific, one of said "U"-shaped housings 28 has a first groove 191 on a face facing the proximal end 205 and a second groove 191, parallel to the first groove, on a face facing the distal end 206. Each of these grooves 191, which extend on a plane orthogonal to an axis of the cylindrical collar 29, is engaged by a rail 190 which extends laterally from the stock 2 and orthogonally to the longitudinal axis 201. As a result, the connection element 27 is constrained to move, with alternate motion, parallel to the plane defined by these rails 190 and orthogonal to the longitudinal axis 201.

The connection element 27 and, in particular, the collar 29, is positioned idle in a slot 211 in a respective cam 21 at the respective first axis of rotation 22. To be more specific, the slot 211 is a hole. This way, the cam 21 is pivoted at the connection element 27 and its axis of rotation 22 is substantially the same as the axis of said cylindrical collar 29. Thanks to the connection element 27 and the pivoting methods, a portion of each bending member 10 is associated idle to the respective slot 211 so as to allow said portion of bending _ _

member 10 to make a translation movement together with the slot 211; in particular, said translation movement takes place in a direction substantially orthogonal to the preferential development direction 202 of the bending member 10. Therefore, the first axis of rotation 22 may make translation movements together with a portion of the respective bending members 10. Note that this portion of the bending members 10 corresponds to the region positioned about halfway along their length. However, in another possible embodiment, this portion might correspond, for example, to an end region of the bending members 10; in this case only the other end of the bending members 10 would be constrained to the stock 2. The crossbow 1 also comprises pushing means 30 for said bolt apt to cooperate with the bending members 10. They include a flexible member 31, such as, for example, a propulsive cable for pushing a bolt, and at least two lever arms 32 positioned on opposite sides of the stock 2 and connected to each other by the flexible member 31. Each of the arms 32 has a first end which is pivoted to the stock 2 at a second axis of rotation 33 and a second end 34 apt to support, and in particular to hold, a portion of said flexible member 31. The flexible member 31 may be secured to the stock 2 or to the arms 32 using a suitable securing device 35. In the case where the flexible member 31 is secured to the stock 2, it will be held by said second end 34 so that it may slide somewhat with respect to the end 34 itself. If, on the other hand, the flexible member 31 is secured to the arms 32, it may further be secured also to said end 34.

During a rotation movement with respect to said second axis of rotation 33, the arms 32 are apt to cooperate with the tensioning means 20 to realize a transfer of energy to said bending members 10 during the loading phase of the crossbow 1 and a transfer of energy from said bending members 10 to said pushing means 30 during the bolt launch phase.

In a first embodiment, each arm 32 forms a single part with a respective cam 21; in this case, said first axis of rotation 22 of the cam 21 is the same as said second axis of rotation 33 of the arm 32. As illustrated in Figure 2B, the arms 32 can be rotated between a first maximum loading position, with arms 32 rotated towards the proximal end 205 of the stock 2 and corresponding to a maximum bending of the bending members 10, and a second maximum discharge position following the launch of the bolt, with arms rotated towards the distal end 206 of the stock 2. Between said first and second positions, there is a neutral position, at which the bending members 10 do not have accumulated elastic energy, as they are in a rest condition in a non-deformed state, as illustrated in Figure 2A. . .

For the sake of clarity, note that Figure 2B intends to show these possible positions through a single drawing; it is intended, obviously, that, in a crossbow 1 according to this invention, the right and left arms 32 will move in a substantially synchronized manner and the two arms 32 will be in the same position at the same time. To be more specific, in the neutral position, the flexible member 31 passes at said second axes of rotation 33 of the arms 32 intercepting them.

Contrast means 50 may also in case be provided, associated to the stock 2 and operatively connected to the cams 21, in order to dampen the motion of the arms 32 and the cams 21; said contrast means 50, for example, include a cylinder 51 with a small hole 52, a piston 53, a spring 54 and a rod 55. The contrast means 50 are connected to the slide 25 by the rod 55 (slotted in, for example) which, therefore, follows its movement parallel to the longitudinal development direction 201 of the stock 2. Depending on the extent of the counter bending permitted for the bending members 10 (also related to their rigidity) and the choices for the dimensioning of the components of the crossbow 1, the contrast means 50 may also dampen the motion of the bending members 10 by means of the interaction with the arms 32 and with the cams 21.

The contrast means 50 are loaded so as to apply a force against the cams 21 when the arms 32 are past said neutral position towards said second maximum discharge position. In fact, when the arms 32 have passed the neutral position, the rod 55 is inserted in the piston 53 and pushes against a special recess (not shown) with a cone- shaped terminal; this way, the piston 53 is pushed inside the cylinder 51 and, thanks to a ring-shaped collar 56 on the outer surface of the piston 53, compresses the spring 54 and pushes the air towards the outside of the cylinder 51 through the small hole 52. This way, a slowing down of the motion of the arms 32 is obtained thanks to the transfer of energy to the spring 54 and thanks to the compression action on the air in the cylinder 51; the fluid dynamic resistance related to the flow of air through the small hole 52 contributes to the dissipation of the kinetic energy possessed by the moving parts. When the arms 32 are between said first maximum loading position and said neutral position, the rod 55 is not in contact with said recess with cone-shaped terminal, of the piston 53 and, therefore, the contrast means 50 do not have any influence on the motion of the arms 32 themselves. These same elastic means represented by the spring 54 can bring the arms 32 back towards the neutral position, so that, at the end of the launch phase, they are in this position again. _ _

The crossbow 1 may comprise a cover 61, positioned at the slide 25 and pivoted to the stock 2 at one end 62, which makes it possible to protect the internal members and to access them only when necessary; to be more specific, this makes it possible to proceed to the replacement of the slide 25. For safety reasons, it is possible to open the cover 61 only when the crossbow 1 is not loaded and the flexible member

31 has been removed. In addition, the cover 61 includes at least one tooth 65 (preferably, a pair of teeth 65) coming out of the cover 61 near its distal end, said at least one tooth 65 having the function of stopping the run of the flexible member 31 at the end of the launch phase in order to prevent the flexible member 31 from falling beyond the cover 61.

Covering members 63 with a "U" -shape (upside down with respect to the corresponding housing 28) may be secured in a reversible manner to said connection elements 27 and cooperate with these in order to keep the bending members 10 in position. In addition, there is a perimeter protective structure 64 which substantially limits the region in which the arms 32 move, in order to assist the user with preventing interference with any objects present nearby and to avoid getting struck by the arms

32 themselves.

During a loading phase of crossbow 1, the user pulls the flexible member 31 towards the proximal end 205 of the stock 2, until the flexible member 31 is engaged in the fastening system 6. During this operation, the arms 32 and the cams 21 rotate in an initial direction around the respective axes of rotation 33, 22; thanks to the edges 23 with eccentric profile on the cams 21 which push against the slide 25, the slot 211 on each cam 21 (and, therefore, the axis of rotation 22) moves orthogonally to the development direction 201 of the stock 2, thereby causing a bending of the respective bending members 10 through the cam 21. The bending members 10, therefore, are in the bent configuration illustrated in Figure 2B and in Figure 3. At the same time, the slide 25 slides towards the distal end 206 of the stock 2. When the maximum loading position is reached and a bolt is placed in a suitable track 8 on the stock 2, the crossbow 1 is ready for launching.

Pressing of the trigger 7 starts a bolt launch phase, during which the flexible member 31 is released from the fastening system 6. The bending members 10 tend to return to the rest position, that is, the non-deformed neutral position, and therefore push on the cams 21 making them rotate in the opposite direction with respect to the loading phase. Through the cams 21, the arms 32 in turn rotate towards the distal end 206 of the stock 2 and pull the flexible member 31, which transfer energy to the bolt. At the same time, the slide 25 moves towards the proximal end 205. . .

When the neutral position is reached, the inertia of the arms 32, the cams 21 and the bending members 10 has them continuing their run past the neutral position tending towards the maximum discharge position; in this portion of the stroke, the bending members 10 are in a bent position towards the longitudinal axis 201 of the stock 2 (that is, in a counter bent configuration with respect to the loaded position) and the flexible member 31 is no longer tensioned. In case of an especially high residual kinetic energy (for example, in case of a very light bolt or of dry firing), the arms 32 may reach said maximum discharge position, in which they are rotated towards the distal end 206, for example, by 25° with respect to the neutral position. In this portion of the stroke, the movement of the cams 21 and the arms 32 is opposed by the contrast means 50, which also dissipate part of the kinetic energy; according to the methods described, these contrast means 50 only operate starting from the neutral position. Thanks to the combined action of the bending members 10 and the spring 54, which tend, obviously, towards the respective non-deformed positions, the entire system is then brought back to the neutral position, where it stops.

Note that the toothings 24 and 26 and the slide 25 are made so that they are mutually engaged even in the stroke between the neutral position and the maximum discharge position; to be more specific, there may be a particular portion of toothing, for example, with deeper teeth and/or possibly with a non-straight profile, to make sure that there is no accidental disengagement. This is especially advantageous for preventing the cams 21 from disengaging the slide 25 when, with the crossbow 1 unloaded and the bending members 10 in the rest condition, the arms 32 are pushed by the user towards the maximum discharge position. Note, in fact, that, with the crossbow 1 unloaded, this movement towards the maximum discharge position may be executed without this involving the deformation of the bending members 10. From the above description it is understood how the end of stroke shock is, therefore, substantially eliminated, since the stopping of the components at the end of the useful run is not sudden as with the known art, but takes place within the stroke between the neutral position and the discharge position, and return. This enables a major reduction in the structural stresses, the noise and the risks related to the use of too light a bolt or no bolt at all. To the same end also the better distribution of the masses of the components, as they are much closer to the center of mass and to the longitudinal axis 201 of the stock 2. A crossbow according to this invention will be lighter than a known-art crossbow and the center of mass will be closer to the handle 4 for same power. _ _

Note that, because of the eccentric profile 23 of the cams 21, when the bending members 10 are in a non-deformed position, the arms 32 can rotate towards the maximum discharge position without this determining the deformation of the bending members 10 themselves. In this case, the spring 54 has the additional function of bringing back and maintaining the arms 32 in the neutral position when the crossbow 1 is unloaded, pushing them towards that position. The slide 25 allows for the synchronization of the motion of the cams 21 and, therefore, of the arms 32: this way, even in case of asymmetries in the elastic characteristics of the bending members, the force acting on the bolt through the flexible member 31 is in any case balanced and does not have any component orthogonal to said track 8. The synchronization of the motion of the cams 21 one with the other and of the arms 32 one with the other guarantees a balanced pull on the flexible member 31 and this absolves a condition necessary for the purpose of precision. This configuration makes it possible to considerably increase (with respect to the known art) the ratio between the stroke of the bolt and the extent of the shifting of the masses of the bending members 10, thereby increasing the efficiency of the conversion between potential and kinetic energy; an adequate profiling of the edges 23 of the cams 21 and, in case, of the edges 26 of the slide 25 also makes it possible to obtain a more marked reduction in the maximum loading force with respect to the known art.

The fact that the slide 25 is removable also makes it possible to easily vary the characteristics of the crossbow 1, adapting them to the use requirements. It can, in fact, be replaced by another slide 25 having profiles 26 which are not straight and/or not parallel (e.g. concave, convex, divergent or convergent), so that, with equal loading stroke, the bending members 10 have a higher or lower degree of deformation, a different level of stored energy and a different force-traction curve. It is also possible to modify the characteristics of the crossbow by replacing the bending members 10 with other bending members of different elastic characteristics. Note that the possibility of easily taking apart the crossbow 1 and replacing its components is linked to the fact that, in the neutral position, there are no members in elastic tension; therefore, the taking apart and the assembly do not require either special tools (e.g. presses) or special caution on the part of the user. The embodiment described above lends itself to several variants. For example, the slide 25 may not be present and the cams 21 may be engaged to each other directly through edges with toothing 24; in this case, these edges could also be smooth, without toothing, but with eccentric profiles. Or both the cams 21 and the slide 25 _ _

could have edges partially smooth and -without toothing, but be able to transfer movement by friction.

The cams 21 themselves could be pivoted to the bending members 10 with methods different from the described slot 211: more generally, said portion of each of the bending members 10 may be associated idle to a portion of a respective cam 21.

For example, each cam 21 may rotate around a pivot which is part of the respective bending members 10 themselves (which could also be just one in number per side of the stock 2). As a further possibility, the cams 21 could be pivoted to the stock 2 so that said first axis of rotation 22 is fixed with respect to the stock 2 and the cams 21 could also not have an eccentric profile: in this case, each cam 21 would include at least one tooth (or an edge) apt to engage and/or cooperate with a respective bending member 10, in order to push it orthogonal to the longitudinal development direction 201 away from or close to the stock 2 itself during the rotation of the cam 21 itself, in order to create a reciprocal transfer of energy between cams 21 and bending members 10.

As a further hypothesis, each cam 21 could cooperate with the bending members 10 positioned on the opposite side of the stock 2.

The cams 21 might be more than two in number (for example, two per side, for a total of four, or one for each bending member 10), and the arms 32 might be more than two in number.

There may also be auxiliary pushing means (not shown) in order to further increase the power of the crossbow 1, these auxiliary pushing means including at least one member with elastic behavior (spring or hydraulic and/or pneumatic device or other) apt to accumulate elastic energy during the loading phase of the crossbow 1 and return it to said pushing means 30 during the bolt launch phase. Said auxiliary pushing means may be connected to said slide 25 and, in particular, be housed to the front of the stock 2, that is, in a position which is substantially opposite to said contrast means 50; in effect, the action of these auxiliary pushing means would be similar to the action exercised by the spring 54, but directed in the opposite direction and active in the phase in which these contrast means 50 are not operative.

These auxiliary pushing means may also be side by side to said contrast means 50, for example, by making that the spring 54 is joined in a stable manner to the cylinder 51 and to the rod 55 so that it may accumulate elastic energy when the arms 32 are brought from the neutral position to the maximum loading position and return it in the opposite direction.

A second embodiment of a device for launching a bolt, indicated with number 70 and illustrated in Figures 8 and 8A, comprises further technical characteristics which _ _

may, however, be present alone or in combination. Parts having the same function and structure maintain the same reference number as in the embodiment described previously and, therefore, are not described again in detail.

The device 70 includes a stirrup 210 secured to the stock 2 at the distal end 206. Said stirrup 210 is apt to house a user's foot: in this way, during the device loading phase, the user can push the stirrup 210 (and, therefore, the device 70) towards the ground with a foot and, at the same time, use the hands to apply force to the flexible member 31 to bring it to the loaded position, managing to apply more force than when the stirrup 210 is not used. As in the embodiment already described, the cover 61 includes a pair of teeth 65 which come out of the cover 61 near to its distal end, in order to arrest the run of the flexible member 31 at the end of the launch phase in order to prevent the flexible member 31 from falling beyond the cover 61. The second ends 34 of the arms 32 have a groove 36 apt to receive a portion of the flexible member 31. To be more specific, said groove 36 is shaped so as to support the flexible member 31, preventing it from being disengaged from the ends 34. The contrast means 50 and, in particular, the cylinder 51, are positioned in the region delimited by the bending members 10, that is, further away from the proximal end 205 than as shown for the first embodiment (Figures 2A to 7). This allows for a greater compactness of the device 70.

Finally, in this second embodiment, the upside down "U"-shaped covering members (indicated with number 63 in the first embodiment, only one of them being represented in figure 4) to be secured to the connection elements 27, are not present, as the connection elements 27 are by themselves able to constrain the cover 61, making it only possible to open it in the neutral position.

A third embodiment of a device for launching a bolt according to this invention is indicated with reference number 71 and is illustrated in Figures 9 A to 10, in which only the essential components are shown in order to understand its functioning with respect to the previous embodiments. Parts having the same function and structure maintain the same reference number as in the embodiments described previously and, therefore, are not described again in detail.

The crossbow 71 also comprises a stock 2 with a longitudinal development direction 201, to which the other components are connected. As well as the handle 4, the fastening system 6 for a flexible member 31, and the track 8, it also, obviously, comprises other components not shown, such as a bolt positioning system, a trigger and other accessories, as with the previously described embodiment. . _

The bending members 10, entirely similar to the ones already described, are represented here with a different method for connection to the stock 2. Their ends, in fact, are in contact with sidebars 75, which are preferably cylindrical, connected to the stock 2 and each bending member 10 is pressed against these sidebars 75 by a cable 76 or similar flexible holding means which envelops the bending member itself and its corresponding member on the opposite side of the stock unit 2. The bending methods for the members 10 are, when all is said and done, similar to those already described, even if they use a simpler solution for their connection to the stock 2. Note, however, that this connection method is in no way limitative for the crossbow 71, just as, the pivoted supports 11 for the bending members 10 are not limitative for the crossbow 1: these solutions may, in fact, be used indifferently in the embodiments shown here as examples.

The crossbow 71 has cams 81 which are constrained and pivoted to the bending members 10 in a manner similar to that described above, and they can also rotate around an axis 22. In this case, no slide is present, but a first and a second cam 81 are hinged on a pivot body 82, which is slidingly associated to the stock 2 in order to run parallel to said longitudinal development direction 201. The cams 81 rotate around a determined axis 83 of the pivot body 82; the axis 83 moves with the pivot 82. The already described contrast means (not shown here) may in case be connected to said pivot body 82. Similarly, the auxiliary pushing means already previously described may also be connected to the same pivot body 82.

Arms 84 are pivoted to the stock 2 at axes of rotation 33, which are distinct from the axes of rotation 22 of the cams 81. In this case, in fact, each arm 84 and the respective cam 81 do not form of a single part, but are separate from each other. The transmission of the rotation movement from one cam 81 to the respective arm 84 (and vice versa) is realized through a connection rod 85 which is pivoted to said cam 81 and to said arm 84. The connection rod 85 might be replaced by more than one connection rods 85, in case pivoted to each other. The methods of loading and of launch of the crossbow 71 are substantially similar to those already described for the previous embodiments and, therefore, are not repeated here.

Also note that the cams 81 may have a particular "L" shape as illustrated in Figure 10, which ensures that, with opportune dimensioning of these, the crossbow 71 allows an operative position with the bending members tensioned, the system for the fastening and releasing the flexible member 31 not tensioned, and arrow in place, from which operative position the crossbow 71 can be practically brought back to the launch position with a manual action. _ .

In fact, a further movement of the arms 84 beyond a position of maximum loading ensures that a plane containing both the axes of rotation 22 intersects the longitudinal axis 201 of the stock 2 in a region between said axis 83 of the pivot 82 and the proximal end 205. In this position, the recall force exercised by the deformed bending members 10 on the cams 81 tends to cause a rotation of the cams 81 in the loading direction instead of in the launch direction: there is, therefore, no danger of an involuntary activation of the crossbow 71. In order to launch, it will then be necessary to first spread the arms 84, so that the axis 83 may pass over said plane containing both axes of rotation 22, getting closer to the proximal end 205. Obviously, the reciprocal pivoting methods for the cams 81, their shape and the separation between cams 81 and arms 84 so that they rotate with respect to axes which are not coincident are technical solutions which, individually or in combination, could also be used in a crossbow similar to the other embodiments described here. Figures HA to HD show a fourth embodiment of a device for launching a bolt, indicated with reference number 72. Parts having the same function and structure maintain the same reference number as in the embodiments described previously and, therefore, are not described again in detail. The device 72 is shown in the rest position in Figure 1 IA and in the loaded position in Figure 1 IB. The arms 84 include teeth 86 positioned on the top surface 87 of the arms 84 themselves, said teeth 86 having the function of stopping the run of the flexible member 31 at the end of the launch phase in order to prevent the flexible member 31 from falling beyond the arms 84. Also in this embodiment, as in the previous one, the "L"-shaped cams 81, dimensioned in an appropriate manner, make it possible for the crossbow 72 to be transported by the user in total safety, even when it is in the loaded position. As illustrated in Figure HC, the further movement of the arms 84 beyond a position of maximum loading makes it possible that a plane 92 containing both axes of rotation 22 of the cams 81 intersects the longitudinal axis 201 of the stock 2 in a region between the axis 83 of the pivot 82 and the proximal end 205 of the stock 2. In this position, the recall force exercised by the deformed bending members 10 on the cams 81 tends to cause a rotation of the cams 81 in the loading direction instead of in the launch direction. In other words, in this position, the moment of force exercised by the bending members 10 on each cam 81, with respect to the axis 83, rotates the cam 81 in the direction indicated by the respective arrow 95. As said, then, there is no danger of involuntary activation of the crossbow 72. In order to launch, it is necessary, in fact, to first spread the arms 84, so that the consequent rotation of the _ _

cams 81 makes the axis 83 pass over the plane 92 containing both axes of rotation 22, getting closer to the proximal end 205.

This embodiment 72 illustrates a further method for associating the bending members 10 to the stock 2. Each end 101 , 102 of a bending member 10 is associated to the stock 2 by means of a first sidebar and a second sidebar, in turn associated to the stock 2. The first sidebar and the second sidebar are in a spaced relation in order to define a housing for said end 101, 102, so that they touch opposite sides of the bending member 10 and, in particular, of said end 101, 102. In the example, the first sidebar consists of a cylindrical stem 15, constrained to the stock 2 close to it; in the example, the second sidebar consists of a support 14, preferably cylindrical, positioned to the outside of the bending member 10 with respect to the stock 2 The end 101, 102 of the bending member 10 is enclosed at the sides between the support 14 and the stem 15, in particular, in order to be slightly jutting out in a longitudinal direction 202 with respect to the stem 15.

The first and the second sidebars also both have a curved profile (in the example, a cylindrical profile) in order to permit, during the bending of the bending member 10, a partial rotation of said end in the housing defined by these. To be more specific, the cylindrical supports 14 are pivotably mounted to the stock 2 in order to be able to make angular displacements around their central axis 214, so as to rotate following the movement of the end of the bending member 10 when the latter, bending, varies its tilt with respect to the stock 2; the stems 15 also act as spacers, in order to keep the bending member 10 slightly displaced from the stock 2. The embodiment described, as well as permitting the connection of the bending members 10 to the stock 2, allows the bending member 10 to easily bend towards the outside during the loading phase and to counter bend towards the stock 2 in the stroke towards the maximum discharge position. Note that, if it is required by particular construction requirements, said first and second sidebars can be positioned at a tract of the bending member 10 not corresponding to an end of it, but instead positioned at a certain distance from the end. In addition, a first tract of the bending member 10 may be associated to the stock 2 using these sidebars, while a second tract of the bending member may be associated using different methods (for example, using the supports 11 already described).

A fifth embodiment of a device for launching a bolt according to this invention is indicated with reference number 73 and is illustrated in figures 12A-12C and 13. _ _

Parts having the same function and structure maintain the same reference number as in the embodiments described previously and, therefore, are not described again in detail.

The device 73 comprises levers 160, each of which has a cam 161 with an appendix 162. The appendix 162 has a guide track which, in the example, consists of a slit 163 which extends into the body of the appendix 162 along the appendix itself. Each cam 161 is associated to the bending members 10 in a manner substantially similar to the methods described previously. In fact, the cam 161 and, therefore, the lever 160, is pivoted to the bending members 10 using a connection element 27 with "C"-shaped housings and it can, therefore, rotate around an axis 22.

The cam 161 extends from the axis of rotation 22 towards the longitudinal axis 201 of the stock 2, while the appendix 162 extends in the opposite direction. To be more specific, the device 73 comprises a pair of levers 160 arranged symmetrically with respect to the stock 2. The cam 161a of a first lever 160a is pivoted to the cam 161b of a second lever 160b at a pivot body 82, which is slidingly associated to the stock 2 to run parallel to the longitudinal development direction 201 of the stock 2 itself. The cams 161a and 161b, then, also rotate around an axis 83 which moves with the pivot 82. Again in this case, as for the embodiments already described, contrast means and/or auxiliary pushing means may be used, possibly connected to the pivot body 82.

The device 73 comprises arms 132, positioned substantially symmetrical with respect to the stock 2. Each arm 132 has a first end which is pivoted to the stock 2 at a respective axis of rotation 33, which is distinct from the axes of rotation 22 of the cams 161. Each arm 132 includes a second end 34 apt to support and retain a portion of a flexible member 31 , in a manner similar to the ones described previously.

The arm 132 is provided with a guide member 135, for example, including a tooth or a wheel, which extends orthogonal to a plane on which said arm 132 lies in the direction of the plane on which the levers 160 lie. Said member 135 is, to be more specific, associated with a side appendix 134 of the arm 132 which, in the embodiment illustrated, is envisaged in a region between the axis of rotation 33 and the second end 34.

The member 135 is apt to engage the guide track 163 provided in the appendix 162 of the respective cam 161; to be more specific, in the embodiment illustrated, the member 135 is a wheel apt to slide in said guide track 163. This way, each arm 132 is operatively connected to a respective cam 161. The wheel 135 is rotationally pivoted to the arm 132 and has a diameter less than the transversal width of the . _

respective guide track 163, so that it can slide in said track 163 remaining in contact with just one edge of the track 163 itself.

Figure 13 shows a detail of the particular method for pivoting the cams 161 to the stock; this method may be also applied in the same way to the other embodiments for the device presented here. In a manner similar to what has already been described, each cam 161 has a hole 211 in which the collar 29 of the respective connection element 27 is housed idle.

The stock 2 includes, on each side, appendices 250 which extend substantially orthogonal to the longitudinal development direction 201. Each appendix has a rail 251 which also extends in a direction which is substantially orthogonal to said longitudinal direction 201. Each appendix 250 may also include an end portion at which a respective arm 132 is pivoted.

On each side of the stock 2, there is a slide 252 which, on a first face, includes means for engaging a respective rail 251. The slide 252, guided by the rail 251, can, therefore, move along the appendix 250. Preferably, the rail 251 and said engagement means are made so that the slide 252 can only make a translation movement along the rail 251 and, therefore, along a direction orthogonal to the longitudinal direction 201, while the slide 252 is prevented from making movements along said longitudinal direction 201. For example, the rail 251 and said means have a dove tail transverse cross section.

A second face of said slide 252, opposite the first face and facing a respective cam 161, has a concave slot, with a cylindrical sector shape, apt to house a corresponding cylindrical portion 165 of the cam 161. The angle described by said cylindrical sector is less than the angle described by said cylindrical portion 165. This way, when the cylindrical portion 165 is housed in the cylindrical sector, the cam 161 can make an angular displacement, of a preset maximum amplitude, with respect to the slide 252; this angular displacement takes place between a first position in which a first edge 167 of the cam 161 is touching a first edge 253 of the slide 252, and a second position in which a second edge 168 of the cam 161 is touching a second edge 254 of the slide 252.

From said second face, a slit extends into the body of the slide 252, orthogonal to this second face and facing the first face. Said slit is apt to house part of a plate portion 166 integral to the cam 161 and positioned outside said cylindrical portion 165 and transversal to it. The slit and the plate portion 166 are made so that they cooperate with each other in order to prevent relative translation movements between the cam 161 and the slide 252 along the axis 22; they are also made so that they do not impede said angular . _

displacement, of preset maximum amplitude, of the cam 161 with respect to the slide 252.

Therefore, during the loading and launch phases, the cam 161 rotates around the axes 22 and 83, both mobile: the axis 83 moves along the longitudinal direction 201, while the axis 22 moves along a direction orthogonal to the longitudinal direction 201, parallel to the rail 251, together with the slide 252. To be more specific, the slide 252 moves towards the axis 201 during the loading phase and moves away from it during the launch phase. Figures 12 A, 12B and 12C illustrate, respectively, the crossbow 73 in a neutral (rest) condition, in a loaded condition, and in a maximum discharge condition.

Before a bolt is launched, the crossbow 73 is initially in the neutral condition (Figure 12A). During the loading phase, the pull on the flexible member 31 causes the rotation of the arms 132 around the axes 33 and the movement of their ends 34 towards the proximal end 205 of the stock 2. The wheels 135, also moving towards the proximal end 205, sliding in the guide tracks 163, apply force to the arms 162, which causes the rotation of the levers 160 around the axes 22. The sliding of the wheels 135 in the guide tracks 163, then, makes it possible that the cams 161 rotate around the axes 22 and bend the bending members 10, thereby accumulating energy which can be used to launch a bolt. The loaded condition is illustrated in Figure 12B.

Note that, unlike the embodiments described previously, in this embodiment, the bending members 10 bend towards the stock 2 during the loading phase and counter bend towards the outside in the launch phase: this is due to the different position of the axis 83 with respect to the plane on which the axes 22 lie in relation to the rotation movements described by the levers 160.

It is evident, in any case, that this bending method for the bending members 10 may also be used for the embodiments described previously (Figures 9 A to 1 ID), and vice versa. In fact, the bending method away from or closing to the stock 2 during the loading phase may be selected through an opportune dimensioning and assembly of the cams, and is substantially unrelated to the other specific characteristics of the embodiments described; it is, therefore, "interchangeable" between the embodiments described.

During the launch phase, the bending members 10 tend to return to their non- deformed configuration and, therefore, apply a force to the cams 161, causing the rotation around the axes 22 towards the distal end 206 of the stock 2. As a result of the force transmitted through the wheels 135, the arms 132 also rotate around the _ .

axes 33 towards the distal end 206 of the stock 2 and pull the flexible member 31 which, in turn, transmits energy to the bolt.

Due to the inertia of the moving parts, the arms 132, the levers 160 and the bending members 10 pass the neutral position and reach a maximum discharge position, shown in Figure 12C, in which the bending members 10 are deformed towards the outside of the stock 2.

Subsequently, the bending members 10 return of their own accord to the non-bent

(neutral) position, also bringing the arms 132 and the levers 160 back to the initial position (Figure 12A). A sixth embodiment of a device for launching a bolt according to this invention is indicated with reference number 74 and is illustrated in figures 14A-14C, 15 and 16.

Parts having the same function and structure maintain the same reference number as in the embodiments described previously and, therefore, are not described again in detail. The device 74 comprises levers 170, each of which has a first portion including a cam 171 constrained and pivoted to bending members 10 in a manner substantially similar to the methods described previously, and a second portion including two appendices 172 integral to the cam 171.

The appendices 172 are substantially identical and parallel to each other and are also positioned on planes parallel to the plane on which the respective cam 171 lies. To be more specific, said second portion includes a block 179 which separates the planes on which said cam 171 and said appendices 172 lie.

Each of these appendices 172 has a guide track, which consists of a first edge 174 with toothing 176; said first edge 174 is optionally facing, at least in part, a second edge 175 with a groove or a rib 177, thereby defining a region 173 between the first edge 174 and the second edge 175.

In a manner similar to the previous descriptions, the cam 171 and, therefore, the lever

170, is pivoted to the bending members 10 using a connection element 27 and it rotates around an axis 22. The device 74 comprises a pair of levers 170, arranged in a symmetrical manner with respect to the stock 2, one on each side of it.

The cam 171a of a first lever 170a is pivoted to the cam 171b of a second lever 170b at a pivot body 82, which is slidingly associated to the stock 2 and can run parallel to the longitudinal development direction 201. The pivot body 82 has a housing apt to slidingly receive a guide 180 joined to the stock 2 and positioned parallel to the longitudinal development direction 201. . _

The cams 171a and 171b also rotate, then, around an axis 83 which moves with the pivot body 82. Again in this case, as for the embodiments already described, contrast means or auxiliary pushing means may be used, connected to the pivot body 82. The device 74 comprises arms 142, each having a first end pivoted rotationally with respect to the stock 2 at a respective axis of rotation 33, which is distinct from the axis of rotation 22 of the respective cam 171. The second end 143 of each arm 142 supports a pulley 145 which, in turn, supports the flexible member 31. The arm 142 and the pulley 145 lie on planes which are parallel to each other. The side edge of the pulley 145 has a groove 147 in which one end 311 of the flexible member 31 is secured and in which the flexible member 31 itself winds. Note that it is not required that the pulley 145 has a side edge which defines a closed line: in fact, the figures show a pulley which has an interrupted side edge.

To be more specific, the pulley 145 has a pivot 146 which rotates jointly with it and which extends orthogonal to the surface of the pulley and is positioned close to a portion of the edge of the pulley 145, so that the pulley has an eccentric side edge with respect to a longitudinal axis 150 of the pivot 146.

The pivot 146 is housed in a slot, or in a hole, in the second end 143 of the arm 142 and may rotate in this hole with respect to the axis 150. The axis 150 makes translation movements together with the second end 143 of the respective arm 142. To be more specific, the arms 142 are two in number and they are arranged symmetrically with respect to the stock 2, one on each side of it. Each arm 142 is placed in spaced relation from the appendices 172 of the respective lever 170, but so that the respective pulley 145 is inserted in a space defined between the same appendices 172. The pivot 146 has two toothed portions 148 (preferably, cylindrical portions), positioned, respectively, at one face of the pulley 145 and at the opposite face, that is, above and below the pulley 145.

Each of these toothed portions 148 engages the guide track of a respective appendix 172 and, in particular, the edge 174 with toothing 176. Figures 14 A, 14B and 14C illustrate, respectively, the crossbow 74 in a neutral condition, in a loaded condition and in a maximum discharge condition. The crossbow 74, before a bolt is launched, is initially in the neutral condition (Figure 14A), in which the bending members 10 are in the non-deformed configuration and the flexible member 31 is partially wound on the pulleys 145. During the loading phase, the pull on the flexible member 31 towards the proximal end 205 causes the unwinding of the flexible member 31 from the pulleys 145 and the rotation of each pulley 145 around the respective axis 150; the toothed portions . _

148 of the pivot 146 rotate together with the respective pulley 145 and, engaging the toothed edges 174 of the guide tracks of the respective appendices 172, move along said guide track, in turn causing the rotation towards the proximal end 205 of the arms 142 and of the levers 170 around the respective axes of rotation 33 and 22. The rotation of the pulley 145 around the respective axis of rotation 150, that is, around the translating axis 150 of the pivot 146, is, therefore, coordinated with a respective cam 171 for a synchronized rotation of the cam 171 itself around the respective first axis of rotation 22. In other words, the pulley 145 moves synchronized with the respective cam 171, with a combined translation and rotation movement.

The rotation of the cams 171, joined to the levers 170, bends the bending members 10 towards the stock 2, thereby accumulating energy which can be used to launch a bolt. The loaded condition is illustrated in Figure 14B.

During the launch phase, the bending members 10 tend to go back to their non- deformed configuration and therefore apply a force to the cams 171, causing the rotation of the levers 170 towards the distal end 206 of the stock 2. The toothed edges 174 have a profile apt to push the pivots 146 towards the distal end 206, causing the rotation of the same (thanks to the engagement of the toothed portions 148 of the pivots 146 on the toothed edges 174 of the appendices 172) and their movement towards the end of the region 173 and towards the longitudinal axis 201 of the stock 2. The pulleys 145 move together with the pivots 146 and, therefore, have both a translation motion towards the distal end 206 and towards the stock 2 (in particular towards the longitudinal axis 201), and a rotation motion around the axis 150 in a direction opposite to that of the loading phase. The combination of the translation motion and the rotation motion of the pulleys 145 draws the flexible member 31 and also winds it in the grooves 147 of the pulleys 145. The flexible member 31, hence, transmits energy to the bolt.

Due to the inertia of the moving parts, the arms 142, the levers 170, the pulleys 145 and the bending members 10 pass the neutral position and reach a maximum discharge position, shown in Figure 14C, in which the bending members 10 are deformed towards the outside. In this position, there is the maximum winding of the flexible member 31 on the pulleys 145, which are almost in contact with each other. Subsequently, the bending members 10 return of their own accord to the non-bent (neutral) position, also bringing the arms 142, the levers 170 and the pulleys 145 to the initial position (Figure 14A).

This embodiment, that is, the crossbow 74, shows certain further advantages with respect to the forms previously described. First of all, the winding of the flexible _ _

member 31 on the pulleys 145 permits a reduction of the lateral dimensions of the device when it is in the neutral position for same loading stroke with respect to the other embodiments. In addition, the winding itself also prevents the flexible member 31 from going slack in the stroke from the neutral position to the maximum discharge position.

The use of pulleys 145 rotating with respect to the arms 142 allows for greater design freedom in order to obtain the desired force-traction curve. In fact, the shape of this curve may be adapted to the requirements by envisaging an opportune profile and rotation angle for the pulleys. By modifying the diameter of the pivot 146 and, therefore, the number of teeth 148, it is also possible to vary the number of rotations carried out by the pulley 145 and the number of windings of the flexible member 31 on it for equal shift along the guide track (in particular along the toothed edges 174), thereby making it possible to vary the stroke of the flexible member 31 for same maximum lateral dimensions of the device.

Finally, in the launch phase, the rotation movement of the pulleys 145 combined with their movement towards the longitudinal axis 201 of the stock 2 makes it possible that the moments of inertia of these are substantially cancelled out and, therefore, the structure of the crossbow 74 and the user are subject to lower stresses. Also, the provision, on each side, of two appendices 172 with two toothed edges 174, engaged by two toothed portions 148 placed on opposite faces of the pulley 145 insures that the movement of the pulley 145 with respect to the arm 170 is more regular, that their interaction is more efficacious, and that the forces acting on the pulley 145 in directions not parallel to its plane are balanced out. However, in principle, there could be just one appendix 172 with toothed edge 174 and a pivot 146 with just one toothed portion 148 which engages said edge 174. A seventh embodiment of a device for launching a bolt according to this invention is indicated with reference number 80 and is represented in figures 17A-17C. Parts having the same function and structure maintain the same reference number as in the embodiments described previously and, therefore, are not described again in detail.

Figures 17A, 17B and 17C show the crossbow 80 in a neutral condition, in a loaded condition and in a maximum discharge condition, respectively. With respect to the crossbows described in the previous embodiments, in the crossbow 80, the cams 171 are associated to the respective bending members 10 at one end of these. . _

To be more specific, each bending member 10 has a proximal end 101 connected to the stock 2 using an already described support 11, and a distal end 102 associated idle to a cam 171 by means of a connection element 27.

The fixed support 19 holds a tract 103 of the bending member 10 in a suitable housing, blocking its translation movements orthogonal to its preferential development direction 202, that is, away from or close to the stock 2 in a direction 203.

At most, the opposite internal walls of the fixed support 19 may, if required, have a plan view profile which is curved and divergent to each other, in order to allow said enclosed tract 103 to assume a certain degree of bending.

Therefore, the bending of the bending member 10 as a result of the action of the cam 171 causes the distal end 102 to move away from or close to the longitudinal axis 201 of the stock 2, while the tract 103 remains steady. Note that, in this case, the bending member 10 is allowed, at least partially, a degree of freedom of translation, along the preferential development direction 202, with respect to the respective connection element 27.

This latter embodiment is advantageous from the point of view of the reduced overall length and the rearing of the center of mass for same loading length. To summarize the various different methods presented to associate a bending member 10 to the stock 2, means for associating a bending member 10 to the stock 2 are generally envisaged, these associating means being apt to prevent a translation of a first tract of the bending member 10 in a direction 203 orthogonal to the stock 2. In certain embodiments, the associating means additionally allow this first tract to bend, and/or to make an angular displacement (that is, a rotation) with respect to the stock 2, and/or a translation in the preferential development direction 202 of the bending member 10.

In the embodiments illustrated in figures 2A to 8A, these associating means comprise supports 11 pivoted to the stock 2 and block both a first and a second tract of the bending member, preventing them from carrying out said translation in a direction 203 orthogonal to the stock 2; to be more specific, said first and second tracts coincide with the ends 101, 102 of the bending member 10.

In another embodiment, illustrated in figures 9 A to 10, said associating means comprise a cable 76 or other flexible retaining member, which in case, cooperates with sidebars 75 joined to the stock 2 in order to block two end tracts 101 and 102. In yet another embodiment, illustrated in figures HA to HD, the associating means comprise a first sidebar and a second sidebar, associated to the stock 2 which, in the example, are a stem 15 constrained to the stock 2 near the latter and a support 14 _ .

positioned on the outside of the bending member 10 with respect to the stock 2.

These means may be envisaged to block end tracts 101, 102 or an intermediate tract

103.

Obviously, it is possible to combine these associating means in order to associate a same bending member 10 to the stock 2.

In a further embodiment illustrated in figures 17A to 17C, a fixed support 19 is envisaged, apt to block a translation movement of a first tract 103 of the bending member 10 in a direction 203 orthogonal to the stock 2, and also block an angular displacement (that is, a rotation) of said first tract 103 with respect to the stock 2. However, the fixed support 19 may permit the bending of the tract 103.

In this latter embodiment, it is further envisaged that a second tract 102 of the bending member 10 is associated idle to a respective cam 171, in particular, by means of a connection element 27.

The principles at the basis of this invention may be applied not just to a crossbow, but also to a bow, to a catapult, or to an apparatus for launching model aircraft or unmanned aerial vehicles or for devices for experimental purposes.

This invention has been described so far with reference to its preferred embodiments.

It is understood that there may be other embodiments which relate to the same inventive core, all included within the scope of the protection of the claims laid out below.

Claims

_ _CLAIMS

1. A device (1; 70; 71; 72; 73; 74; 80) for launching a bolt or a launch object in general, comprising:

- a stock (2) having a longitudinal development direction (201) between a rear or proximal end (205) and a front or distal end (206),

- at least two bending members (10) associated to said stock (2) on opposite sides of it and having a preferential development direction (202), said bending members (10) being apt to be subjected to bending in order to accumulate and supply energy usable to launch said bolt, and released in a rest condition,

- tensioning means (20) of said bending members (10),

- pushing means (30) of said bolt apt to cooperate with said bending members

(10), wherein said tensioning means (20) comprise at least two cams (21; 81 ; 161; 171) arranged on opposite sides of the stock (2), each of which is pivoted at a respective first axis of rotation (22) and is associated to at least one corresponding bending member (10), so that an angular displacement of said cam (21; 81; 161; 171) around said first axis of rotation (22) determines a bending action on said at least one corresponding bending member (10), and said pushing means (30) comprise at least two arms (32; 84; 132; 142) arranged on opposite sides of the stock (2) and connected to each other through a flexible member (31), wherein each of said arms (32; 84; 132; 142) has a first end pivoted at a second axis of rotation (33) and a second end (34; 143) apt to support a portion of said flexible member (31), each of said arms (32; 84; 132; 142) being operatively connected to a respective cam (21; 81; 161; 171), so that a rotation of each arm (31) in a first rotation direction determines a bending of said bending members (10) by means of the cam (21; 81; 161; 171) during a loading phase of the device (1; 70; 71; 72; 73; 74; 80) and that, during a launch phase of said bolt, a return of the bending members (10) towards said rest condition determines, by means of the cam (21; 81; 161; 171), a rotation in the opposite direction of each arm (31).

2. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said bending members (10) are arranged so that said preferential development direction (202) is substantially parallel to said longitudinal development direction (201) of said stock (2).

3. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said bending members (10) are positioned substantially adjacent to said stock _ .

(2).

4. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, wherein said at least two bending members (10), said at least two cams (21; 81; 161; 171) and said at least two arms (32; 84; 132; 142) are arranged in a manner substantially symmetrical with respect to said stock (2).

5. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, comprising, on each side of said stock (2), at least two bending members (10) opposite to each other with respect to a plane on which said cams (21; 81; 161; 171) lie, forming, overall, a group of at least four bending members (10) symmetrical with respect to the longitudinal development direction (201) of the stock (2).

6. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, wherein a portion of each of said bending members (10) is associated idle to a portion (211) of a respective cam (21; 81; 161; 171), so as to allow said portion of bending member (10) to make a translation movement together with said portion (211) of cam, said translation movement taking place along a direction substantially orthogonal to said preferential development direction (202) of said bending member (10).

7. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said portion of a respective cam (21; 81; 161; 171) is a slot (211) in said respective cam (21; 81; 161; 171) at the respective first axis of rotation (22).

8. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, comprising a connection element (27) positioned idle in said slot (211), said connection element (27) comprising a connection member apt to move said portion of said at least one bending member (10).

9. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said connection element (27) comprises two of said connection members, positioned symmetrically and connected to each other by a collar (29) which is engaged in said slot (211) of a respective cam (21; 81; 161; 171), each of said connection members being apt to move said portion of a respective bending member (10).

10. The device (1; 70; 71; 72; 73; 74; 80) according to claim 8 or 9, wherein said connection member includes a housing (28) substantially "U" or "C" shaped and apt to house said portion of said bending member (10).

11. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, wherein said cams (21) have an edge (23) equipped, at least partially, with a toothing (24). _ _

12. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, further comprising a slide (25) associated to the stock and positioned between the opposing cams (21), said slide (25) being apt to slide in said stock (2) substantially parallel to said longitudinal development direction (201), said slide being engaged on opposite sides to said cams (21) to coordinate an angular displacement thereof.

13. The device (1; 70; 71; 72; 73; 74; 80) according to claims 11 and 12, wherein said slide (25) has toothed edges (26) which cooperate with the respective toothings (24) of said cams (21).

14. The device (1; 70; 71; 72; 73; 74; 80) according to claim 12 or 13, wherein said slide (25) is removable from said stock (2).

15. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 1 to 10, comprising a pivot body (82) of determined axis (83) and slidingly associated to said stock (2) to run parallel to said longitudinal development direction (201), wherein a first of said cams (81; 161; 171) and a second of said cams (81; 161;

171) are hinged on said pivot body (82).

16. The device (1; 70; 71; 72; 73; 74; 80) according to any one of preceding claims, wherein each of said arms (32) forms a single part with a respective cam (21) and said second axis of rotation (33) of said arm (32) is coincident with said first axis of rotation (22) of said respective cam (21).

17. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 1 to 15, wherein each of said arms (84) is connected to a respective cam (81) by at least one connection rod (85) pivoted to said arm (84) and to said cam (81).

18. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 1 to 15, wherein each of said arms (132) is operatively connected to a respective cam

(161) by means of a guide member (135) integral to the arm (132) and which engages slidingly a guide track (163) provided in an appendix (162) of said cam (161).

19. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 1 to 15, wherein said second end (143) of each of said arms (142) supports a pulley (145) rotatably associated to the respective arm (142), wherein said pulley (145) is apt to rotate around an axis of rotation (150), said pulley (145) being further apt to wind, at least partially on itself, said flexible member (31) during a rotation movement around said axis of rotation (150).

20. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said pulley (145) has an eccentric profile with respect to said axis of rotation (150). _ .

21. The device (1; 70; 71; 72; 73; 74; 80) according to claim 19 or 20, wherein the rotation of said pulley (145) around said axis of rotation (150) is coordinated with a respective cam (171) for a synchronized rotation of said respective cam (171) around the respective first axis of rotation (22).

22. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said pulley (145) includes a pivot (146) rotating jointly with the pulley (145) and having a longitudinal axis coincident with said axis of rotation (150) of the pulley (145), said pivot (146) further comprising at least one toothed portion (148), and wherein said respective cam (171) is integral to an appendix (172) equipped with a guide track (173), said guide track (173) comprising an edge

(174) equipped with a toothing (176) apt to be engaged by said at least one toothed portion (148) of said pivot (146).

23. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, wherein said arms (32; 84; 132; 142) are rotatable between a first maximum loading position with said arms (32; 84; 132; 142) rotated towards said rear or proximal end (205) of the stock (2) and corresponding to a maximum bending of the bending members (10), and a second maximum discharge position with the arms (32; 84; 132; 142) rotated in the direction of said front end (206) of the stock (2), between said first maximum loading position and said second maximum discharge position there being a neutral position at which said bending members (10) are in said rest condition not presenting accumulated elastic energy.

24. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, further comprising contrast means (50) associated to said stock (2), and operatively connected to said cams (21; 81; 161; 171).

25. The device (1; 70; 71; 72; 73; 74; 80) according to claim 23 and according to claim 24, wherein said contrast means (50) are loaded so as to exert a force on said cams (21; 81; 161; 171) only when said arms (32; 84; 132; 142) are beyond said neutral position towards said second maximum discharge position.

26. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 23 to 25, further comprising elastic means (54) apt to bring back said arms (32; 84; 132; 142) towards said neutral position.

27. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 12 to 14 and according to any one of claims 24 to 26, wherein said contrast means (50) and/or said elastic means (54) are operatively connected to said slide (25).

28. The device (1; 70; 71; 72; 73; 74; 80) according to claim 15 and according to any one of claims 24 to 26, wherein said contrast means (50) and/or said elastic

.

means (54) are connected to said pivot body (82).

29. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, further comprising auxiliary pushing means including at least one elastic member apt to accumulate energy during said loading phase of the device (1; 70; 71; 72; 73; 74; 80) and apt to supply said energy to said pushing means (30) during said launch phase of said bolt.

30. The device (1; 70; 71; 72; 73; 74; 80) according to any one of claims 24 to 28 and according to claim 29, wherein said auxiliary pushing means are side by side to said contrast means (50).

31. The device (1; 70; 71; 72; 73; 74; 80) according to claim 23, wherein, in said neutral position, said flexible member (31) substantially intercepts said second axes of rotation (33) of said arms (32; 84; 132).

32. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, comprising associating means (11; 14, 15; 75, 76) of at least one of said bending members (10) to said stock (2), wherein said associating means (11; 14,

15; 75, 76) are apt to prevent a translation of a first tract (101, 102, 103) of said at least one bending member (10) in a direction (203) orthogonal to said stock (2), and to allow said first tract (101, 102, 103) a bending movement, and/or an angular displacement with respect to said stock (2), and/or a translation in said preferential development direction (202) of said at least one bending member

(10).

33. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein said associating means (11; 14, 15; 75, 76) are apt to prevent said translation in said orthogonal direction (203) to a first tract (101, 102, 103) and to a second tract (101, 102, 103) of said at least one bending member (10).

34. The device (1; 70; 71; 72; 73; 74; 80) according to claim 32 or 33, wherein said associating means (11; 14, 15; 75, 76) comprise a cable (76) or other flexible retaining member.

35. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, comprising a fixed support (19) apt to prevent a translation of a first tract

(101, 102, 103) of at least one of said bending members (10) in a direction (203) orthogonal to said stock (2), wherein said fixed support (19) also prevents an angular displacement of said first tract (101, 102, 103) with respect to said stock

(2).

36. The device (1; 70; 71; 72; 73; 74; 80) according to the preceding claim, wherein a second tract (101, 102, 103) of said at least one bending member (10) is associated idle to one of said cams (21; 81; 161; 171). _

37. The device (1; 70; 71; 72; 73; 74; 80) according to any one of the preceding claims, wherein said device is a crossbow (1; 70; 71; 72; 73; 74; 80).