PULLEY BLOCK FOR COMPOUND BOW AND NOVEL COMPOUND BOW

Description

TECHNICAL FIELD

The present disclosure relates to the technical field of compound bows, and in particular, to a pulley block for a compound bow and a novel compound bow.

BACKGROUND ART

A compound bow is mainly assembled by a riser, a pulley block, a main string, a cable, a limb, a limb pocket and other components, and generally has a three-string structure and a five-string structure. The both are same in principle, namely through a backward drawing and deformation of the main string, the kinetic energy of drawing the bow through the pulley block is converted into the potential energy of radial drawing the two cables, and then the limbs are drawn to store energy. When the main string is released, the limb is first deformed, the pulley block is driven to rotate through the cable, which in turn the main string is driven to rebound to shoot an arrow on the string.

By means of the pulley block for the compound bow, the draw force curve can be improved and labor can be saved. The traditional pulley block usually includes one main string pulley and one or two cable pulleys fixedly connected to the main string pulley, which have the same angular velocity and different linear velocities. Due to the fixed geometries of the main string pulley and the cable pulleys, the draw force curve of the pulley block, the let-off and the efficiency of the pulley block are fixed, and a mutational draw force curve cannot be realized within a single shooting cycle. In order to save labor at ends, the draw force is inevitably reduced gradually during drawing for anchoring, such that the pulley block stores less energy than the one that maintains the calibrated poundage until the anchoring point at the end in an ideal state, which is difficult to further improve the efficiency of the compound bow.

SUMMARY

In order to solve the technical problem that it is difficult to further improve the efficiency of an existing compound bow, the present disclosure provides a pulley block for a compound bow and a novel compound bow.

In one aspect, the present disclosure provides the following technical solution: a pulley block for a compound bow, comprising a main string pulley, a first cable pulley, a second cable pulley and an axle; wherein each of the first cable pulley and the second cable pulley comprises a cable pulley body, an adjust rod, a coupler and a first reset spring; the adjust rod is hingedly connected to the cable pulley body at one end of the adjust rod, and another end is a free end; the cable pulley body is provided with a first stop-rotating edge and a second stop-rotating edge, the adjust rod is capable to lift up a cable when it rests against the first stop-rotating edge, the adjust rod is capable to lift down the cable when it rests against the second stop-rotating edge; the first reset spring is capable to make the adjust rod rest against the first stop-rotating edge, and the coupler is capable to couple or decouple the adjust rod from the cable pulley body when the cable pulley body is rotated to a set position.

By adopting the above technical solutions, the pulley block for the compound bow according to the present disclosure is provided with two sets of cable pulleys, and each set of the cable pulleys has two states, i.e., the adjust rod is coupled or decoupled with the cable pulley body. Before drawing the bow, one adjust rod of the cable pulleys is in the state of coupling with the cable pulley body, and the other adjust rod of the cable pulley is in the state of decoupling with the cable pulley body. Assuming that the first cable pulley is the state of coupling, and the second cable pulley is the state of decoupling, at this time the draw force curve (mainly holding curve) of the compound bow is only related to the first cable pulley, and has nothing to do with the second cable pulley. When drawing the bow to the set position (close to the end), the connection state between the adjust rods and the two sets of cable pulleys changes (the original is in the state of coupling, and is converted to the state of decoupling; and the original is in the state of decoupling, and is converted to the state of coupling). At this time the draw force curve (mainly the let-off curve) of the compound bow is only related to the second cable pulley, and has nothing to do with the first cable pulley. The bow is continued to be drawn to its full extent, at this time the let-off of the pulley block is only related to the second cable pulley, and has nothing to do with the first cable pulley. At the time of releasing, contrary to the action of drawing to the full extent, when the cable pulley rotates to the set position, the connection state between the adjust rods of the two sets of cable pulleys and the cable pulley body changes again, at which time the force application curve is only related to the first cable pulley, and has nothing to do with the second cable pulley.

According to the present disclosure, the transformation of the pulley block's draw force characteristic curve within a single shooting cycle (from drawing to a full extent to releasing) can be achieved by switching the connection state between the adjust rod and the cable pulley body (belonging to the variable cable pulley technology, which possesses several draw force curves within a single shooting cycle), and by adjusting the draw force characteristic curves of the first cable pulley and the second cable pulley, it is possible to adjust the energy storage and conversion efficiency of the pulley block under certain specifications (poundage, draw length, etc.), and to increase the energy storage and conversion efficiency of the pulley block if the first cable pulley requires a higher drawing force compared to the second cable pulley.

In a preferred embodiment, the coupler comprises a lock block, a guide rod and a track transfer block; the cable pulley body is provided with a slide hole, the lock block is provided in the slide hole in a resilient and floated manner, the guide rod is fixedly provided on the lock block, the track transfer block is fixedly provided on the axle or on a limb of the compound bow, for driving the guide rod and the lock block move outwardly to decouple the adjust rod from the cable pulley body.

By adopting the above solution, a purely mechanical coupler is used for reliable application.

In a preferred embodiment, the track transfer block is provided with a inclined surface by which the guide rod is driven to move.

By adopting the above technical solution, the driving force generated by the inclined surface converts the rotary motion of the track transfer block into the axial motion of the lock block, such that the coupling and decoupling operation can be achieved, with a simple structure and good repeatability of the movement.

In a preferred embodiment, the lock block is provided with a recess, the recess is provided with a second reset spring, the second reset spring is resisted with the cable pulley body, for pushing the lock block to be in a locked position.

By adopting the above technical solution, the second reset spring is restricted in the recess and cannot be twisted when compressed and deformed, and it is not easy to fall off and be lost when it is blocked above by the cable pulley body.

In a preferred embodiment, the cable pulley body is provided with a notch, and a hinged end of the adjust rod is provided in the notch.

By adopting the above technical solution, the notch can provide rotational space for the adjust rod, while the adjust rod, when rotated against the second stop-rotating edge, no longer supports the cable, which then falls downward.

In a preferred embodiment, the coupler is an electronic coupler.

In a preferred embodiment, the electronic coupler comprises an electromagnet and a position sensor; the position sensor is capable to detect whether the cable pulley body is rotated to the set position, and the electromagnet is operated when the cable pulley body is rotated to the set position, such that a core of the electromagnet is extended or retracted to couple or decouple the adjust rod from the cable pulley body.

By adopting the above technical solution, the functions realized by purely mechanical structures can also be realized and similar technical effects can be obtained.

In the other aspect, the present disclosure further provides a novel compound bow, comprising a riser, an upper limb, a lower limb, an upper pulley block, a lower pulley block and a main string; wherein the novel compound bow further comprises a first cable, a second cable, a third cable, a fourth cable, a first cable hang ring, a second cable hang ring, a third cable hanging and a fourth cable hang ring; the upper pulley block and lower pulley block both adopt the pulley block for the compound bow above mentioned;

• • the first cable hang ring and the second cable hang ring are provided on the axle of the lower pulley block, the third cable hang ring and fourth cable hang ring are provided on the axle of the upper pulley block;
  • one end of the first cable is hooked to the first cable pulley of the upper pulley block, with another end to the first cable hang ring;
  • one end of the second cable is hooked to the second cable pulley of the upper pulley block, with another end to the second cable hang ring;
  • one end of the third cable is hooked to the first cable pulley of the lower pulley block, with another end to the third cable hang ring; and
  • one end of the fourth cable is hooked to the second cable pulley of the lower pulley block, with another end to the fourth cable hang ring.

In summary, the present disclosure includes at least one of the following beneficial technical effects:

• • 1. In the present disclosure, the transformation of the pulley block's draw force characteristic curve (belonging to the technology of variable cable pulley, which has several draw force curves within a single shooting cycle) within a single shooting cycle (from drawing to a full extent to releasing) can be achieved by switching the connection state between the adjust rod and the cable pulley body, and by adjusting the draw force characteristic curves of the first and second cable pulleys, under specific indexes (poundage, draw length, etc.), the energy storage capacity and conversion efficiency of the pulley block can be adjusted, and if the first cable pulley needs more draw force compared with the second cable pulley, the energy storage capacity and conversion efficiency of the pulley block can be improved;
  • 2. Adopting a purely mechanical coupler, reliable application can be achieved, with a simple structure and a good action repeatability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a three-dimensional (3D) view of a pulley block for a compound bow provided in an embodiment according to the present disclosure;

FIG. 2 depicts a 3D view, from another view angle, of the pulley block for the compound bow provided in an embodiment according to the present disclosure;

FIG. 3 depicts a 3D view of a first cable pulley provided in an embodiment according to the present disclosure;

FIG. 4 depicts a 3D view of a second cable pulley provided in an embodiment according to the present disclosure;

FIG. 5 depicts a 3D view of a novel compound bow provided in an embodiment according to the present disclosure;

FIG. 6 depicts a 3D view, from another view angle, of the novel compound bow provided in an embodiment according to the present disclosure;

FIG. 7 depicts a front view of the novel compound bow provided in an embodiment according to the present disclosure;

FIG. 8 depicts an enlarged view at A in FIG. 7;

FIG. 9 depicts an enlarged view at B in FIG. 7.

NOTE OF THE CHARACTER REFERENCES

10, pulley block; 1, main string pulley; 2, first cable pulley; 21, cable pulley body; 211, first stop-rotating edge; 212, second stop-rotating edge; 213, slide hole; 214, notch; 22, adjust rod; 23, coupler; 231, lock block; 2311, recess; 232, guide rod; 233, track transfer block; 2331, inclined surface; 234, second reset spring; 24, first reset spring; 3, second cable pulley; 4, axle; 30, riser; 40, upper limb; 50, lower limb; 60, upper pulley block; 70, lower pulley block; 80, main string; 81, first cable; 82, second cable; 83, third cable; 84, fourth cable; 85, first cable hang ring; 86, second cable hang ring; 87, third cable hang ring; 88, fourth cable hang ring

DETAILED DESCRIPTION

The present disclosure will be further described below in details with reference to FIGS. 1 to 9.

Embodiment I

Referring to FIGS. 1 to 4, an embodiment of the present disclosure discloses a pulley block 10 for a compound bow comprising a main string pulley 1, a first cable pulley 2, a second cable pulley 3 and an axle 4. The first and second cable pulleys 2 and 3 are provided on both sides of the main string pulley 1 and are fixedly connected to the main string pulley 1. Each of the first and second cable pulleys 2 and 3 comprises a cable pulley body 21, an adjust rod 22, a coupler 23 and a first reset spring 24. The adjust rod 22 is hinged at one end on the cable pulley body 21, and the other end is a free end. The cable pulley body 21 is provided with a first stop-rotating edge 211 and a second stop-rotating edge 212; the adjust rod 22 can lift up the cable when it rests against the first stop-rotating edge 211, and the adjust rod 22 can cause the cable to fall down when it rests against the second stop-rotating edge 212. The first reset spring 24 is used to make the adjust rod 22 against the first stop-rotating edge 211, the coupler 23 is used to couple or decouple the adjust rod 22 from the cable pulley body 21 when the cable pulley body 21 is rotated to a set position.

When the coupler 23 is in a coupling locked state, the adjust rod 22 rests against the first stop-rotating edge 211, and the adjust rod 22 cannot rotate; when the coupler 23 is unlocked, the adjust rod 22 is able to rotate. Under the pressure of the cable, as well as the rotation of the cable pulley, the adjust rod 22 rests against the second stop-rotating edge 212, and while the adjust rod 22 cannot top the cable or greatly reduces the jacking height of the cable, in other words, a change presents in the shape of the cable pulley.

Referring to FIG. 3, the coupler 23 comprises a lock block 231, a guide rod 232 and a track transfer block 233. The cable pulley body 21 is provided with a slide hole 213, the lock block 231 is resiliently and floatingly provided within the slide hole 213. The guide rod 232 is fixedly provided on the lock block 231, and the track transfer block 233 is fixedly provided to the axle 4 or on the limb of the compound bow for driving the guide rod 232 and the lock block 231 to move outwardly to decouple the adjust rod 22 from the cable pulley body 21. When the lock block 231 extends the slide hole 213, it can block the rotation of the adjust rod 22, and when the lock block 231 retracts the slide hole 213, it cannot block the rotation of the adjust rod 22. The track transfer block 233 is capable to drive the guide rod 232 to move, the lock block 231 and the guide rod 232 are of integrated structure, and the lock block 231 will be synchronized to move. In the embodiment, a purely mechanical type of coupler is adopted for reliable movement.

Referring to FIG. 3, the track transfer block 233 is provided with a inclined surface 2331, through which the guide rod 232 is driven to move. Through the driving force generated by the inclined surface 2331, the rotational movement of the track transfer block 233 is converted into the axial movement of the lock block 231, such that the coupling and decoupling operation can be achieved, with a simple structure and a good repeatability of the movement.

Referring to FIG. 3, the lock block 231 is provided with a recess 2311, the recess 2311 is provided with a second reset spring 234, and the second reset spring 234 is rested against the cable pulley body 21 for pushing the lock block 231 in the locked position. The second reset spring 234 is restricted within the recess 2311, will not twist when compressed and deformed, and is not easily dislodged and lost when it is blocked above by the cable pulley body 21.

Referring to FIG. 3, the cable pulley body 21 is provided with a notch 214, and the hinged end of the adjust rod 22 is provided within the notch 214. The notch 214 can provide rotational space for the adjust rod 22, while the adjust rod 22 rotates against the second stop-rotating edge 212 when it no longer supports the cable, and the cable will fall downwardly.

The pulley block 10 for the compound bow according to the present disclosure is provided with two sets of cable pulleys, and each set of cable pulleys has two states, i.e., the adjust rod 22 is coupled or decoupled with the cable pulley body 21. Before drawing the bow, the adjust rod 22 of one of the cable pulleys is in the state of coupling with the cable pulley body 21, and the adjust rod 22 of the other cable pulley is in the state of decoupling with the cable pulley body 21. Assuming that the first cable pulley 2 is in the state of coupling, and the second cable pulley 3 is in the state of decoupling, at this time the draw force curve of the compound bow (mainly holding curve) is only related to the first cable pulley 2, and has nothing to do with the second cable pulley 3. The bow is drawn to the set position (close to the end), the connection state between the adjust rods 22 of the two sets of cable pulley and the cable pulley bodies 21 have been changed (the original is in the state of coupling, then is converted to the state of decoupling, or the original is in the state of decoupling, then is converted to the coupling). At this time the compound bow is in a coupled state. For the coupled state), at this time the draw force curve (mainly let-off curve) of the compound bow is only related to the second cable pulley 3, and has nothing to do with the first cable pulley 2. The bow is continued to be drawn to a full extent, the let-off of the pulley block 10 is only related to the second cable pulley 3, and has nothing to do with the first cable pulley 2. In the case of releasing, contrary to the action of drawing the bow to the full extent, the connection state between the adjust rods 22 of the two sets of cable pulleys to the cable pulley bodies changes again when the cable pulleys are rotated to the set position, at which time the force application curve is only related to the first cable pulley 2 and has nothing to do with the second cable pulley 3.

In the present disclosure, the transformation of the draw force characteristic curve of the pulley block 10 within a single shooting cycle (from drawing to the full extent to releasing) can be achieved (belonging to the technology of variable cable pulley, which has several draw force curves within a single shooting cycle), by switching the connection state between the adjust rod 22 and the cable pulley body 21; and by adjusting the draw force characteristic curves of the first cable pulley 2 and the second cable pulley 3, the energy storage capacity and conversion efficiency of the pulley block 10 can be adjusted under the specific indexes (pounds, draw length, etc.). If the first cable pulley 2 needs more draw force compared with the second cable pulley 3, the energy storage capacity and conversion efficiency can be improved.

In the present disclosure, the coupler may also be an electronic coupler, for example, an electronic coupler controlled with an electromagnet or a motor. When the electromagnet-controlled electronic coupler is adopted, the solution is specifically described as follows: the electronic coupler comprises an electromagnet and a position sensor, the position sensor is used to detect whether or not the cable pulley body is rotated to the set position, and the electromagnet is used to act when the cable pulley body is rotated to the set position, such that the core of the electromagnet is extended or retracted, in order to couple or decouple the adjust rod from the cable pulley body. The same function as the coupler 23 of the above mechanical structure can be also achieved in the present solution, and similar technical effects can be obtained.

Embodiment II

Referring to FIGS. 5 and 6, the present embodiment discloses a new type of compound bow, comprising a riser 30, an upper limb 40, a lower limb 50, an upper pulley block 60, a lower pulley block 70 and a main string 80, and further comprising a first cable 81, a second cable 82, a third cable 83, a fourth cable 84, a first cable hang ring 85, a second cable hang ring 86, a third cable hang ring 87 and a fourth cable hang ring 88. The upper pulley block 60 and lower pulley block 70 both utilize the pulley block 10 for the compound bow described above.

Referring to FIGS. 7 to 9, the first and second cable hang rings 85 and 86 are provided on the axle 4 of the lower pulley block 70, and the third and fourth cable hang rings 87 and 88 are provided on the axle 4 of the upper pulley block 60. The first cable 81 is hooked on one end to the first cable pulley 2 of the upper pulley block 60, with the other end to the first cable hang rings 85. The second cable 82 is hooked on one end to the second cable pulley 3 of the upper pulley block 60, with the other end to the second cable hang ring 86. The third cable 83 is hooked on one end to the first cable pulley 2 of the lower pulley block 70, with the other end to the third cable hang ring 87. And the fourth cable 84 is hooked on one end to the second cable pulley 3 of the lower pulley block 70, with the other end to the fourth cable hang ring 88.

Although in the present disclosure, five-string is disclosed, it is still considered to be a three-string system, because in a single shooting cycle, only one of the first cable pulley 2 and the second cable pulley 3 operates, they both will not operate at the same time. The cable corresponding to the one that operates is in an operating taut state, and the cable corresponding to the one that does not operate is in a relative slackness state. The specific realization of the principle and the beneficial effects have been described in the above embodiments, and will not be repeated herein.

The above are the preferred embodiments of the present disclosure, and is not intended to limit the scope of the present disclosure. Therefore, all equivalent changes made according to the structure, shape and principle of the present disclosure shall be covered by the scope of the present disclosure.