Self-synchronous labor-saving driving mechanism for slingshot

Abstract

The application discloses a self-synchronous labor-saving driving mechanism for a sling bow, relates to the technical field of composite bows, and comprises symmetrical left and right bow wheel assemblies, wherein the bow wheel assembly comprises an integrally formed bow wheel and a ball screw, the bow wheel is provided with a threaded groove, and a large-diameter spiral groove with gradually increasing diameter is arranged at the tail end of the threaded groove; the nut of the ball screw is fixed with a bow body, and the left and right bow strings are fixedly connected after being crossed to connect a bullet positioning assembly; a synchronous adjusting mechanism is arranged at the end of the bow wheel and comprises a synchronous ring, an elastic adjusting piece and a distance sensing piece; and the bullet positioning assembly comprises a bullet frame and an antiskid buffer pad. The large-diameter spiral groove is used for increasing the force arm to save labor, the nominal diameter of the ball screw is smaller than the diameter of the bow wheel, so that secondary labor saving is realized, the energy is stored by utilizing the elastic deformation of the bow arm itself, the energy storage structure is avoided from being attenuated, the overall structure is simple, the manufacturing cost is low, the service life is long, and the labor-saving driving mechanism is suitable for various manual pulling type bow crossbows.

Description

Technical Field

[0001] This invention relates to the field of composite bow technology, specifically to a force-saving drive mechanism for pulling the bowstring, which is particularly suitable for the bowstring drive structure of various manually pulled crossbows. Background Technology

[0002] Existing bows primarily involve manually pulling the projectile at the center of the bowstring. The force is applied to the bowstring, which is fixed at both ends to bow arms. Under the force, the bow arms undergo elastic deformation to store energy. Upon release, the reaction force of the bow arms propels the projectile. In this design, the elastic deformation of the bow arms intensifies with increasing pulling distance, leading to continuously rising resistance and progressively increasing difficulty in pulling. This places high demands on the user's strength and results in a poor user experience.

[0003] To address the aforementioned labor-saving issues, existing technologies have introduced solutions that incorporate a rotatable bow arm with an energy storage structure connected to the front end of the bow arm. However, this type of structure significantly increases the overall complexity of the bow, raising manufacturing difficulty and usage costs. Furthermore, the performance of the dedicated energy storage structure degrades over time, gradually reducing its energy storage capacity and directly impacting the initial velocity, accuracy, and other aspects of the projectile's quality. Additionally, the maintenance and replacement costs for this type of structure are relatively high.

[0004] In addition, in the existing bowstring pulling drive structure of crossbows, the transmission components on the left and right sides are prone to uneven force, which leads to asynchronous deformation of the bow arms on both sides. This not only further increases the pulling resistance, but also affects the accuracy of the projectile direction. The existing synchronization structure is mostly a rigid connection, which has poor synchronization adjustment effect and is prone to reduced service life due to mechanical wear. Summary of the Invention

[0005] In view of this, the present invention provides a self-synchronizing force-saving drive mechanism for slingshots, which solves the technical problems of existing crossbows that require a lot of effort to pull, the energy storage structure is prone to attenuation, and the left and right transmission components are not synchronized. It achieves the effects of effort-saving pulling, stable energy storage capacity, and self-synchronized movement of the left and right components with flexible adjustment, while reducing the complexity of the bow structure and manufacturing cost.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A self-synchronizing, force-saving drive mechanism for a slingshot includes a symmetrically arranged left bow wheel assembly and a right bow wheel assembly. The left bow wheel assembly includes a left bow wheel and a left-handed ball screw integrally formed with the left bow wheel. The left bow wheel has a left-handed threaded groove for accommodating the left bowstring. The right bow wheel assembly includes a right bow wheel and a right-handed ball screw integrally formed with the right bow wheel. The right bow wheel has a right-handed threaded groove for accommodating the right bowstring. The nuts of both the left-handed and right-handed ball screws are fixedly connected to the bow body. One end of the left bowstring is fixed to the left bow arm, and the other end is fixedly connected to one end of the right bowstring. The other end of the right bowstring is fixed to the right bow arm. The tail ends of the left-handed and right-handed threaded grooves are... Each bow wheel is equipped with at least one large-diameter spiral groove, the diameter of which gradually increases along the rotation direction of the bow wheel, and the spiral direction is consistent with the spiral direction of the thread groove on the bow wheel. A synchronous adjustment mechanism is integrally provided on both the left and right bow wheels. The synchronous adjustment mechanism includes a synchronous ring and an adjusting component. The synchronous ring is coaxially fixed to the end of the bow wheel, and the adjusting component is detachably fixed to the synchronous ring. The two adjusting components maintain the same rotational speed of the two bow wheels through the resistance formed by their contact. A projectile positioning assembly is provided at the connection between the left and right bow strings. The projectile positioning assembly includes a projectile frame and an anti-slip buffer pad. The anti-slip buffer pad is located on the inner wall of the projectile frame and is used to elastically abut against the projectile.

[0008] Furthermore, the adjusting element is an elastic ring circumferentially disposed on the outer wall of the synchronization ring, and the two elastic rings are arranged in abutment against each other.

[0009] Alternatively, the adjusting element is a locking tooth circumferentially arranged on the outer wall of the synchronizing ring, with two locking teeth meshing relative to each other.

[0010] Furthermore, both the left and right bow wheels are variable diameter shafts. The small diameter section at the front end of the variable diameter shaft has the left-hand threaded groove or the right-hand threaded groove, and the large diameter section at the rear end has the large diameter helical groove. The variable diameter shaft is a stepped shaft or a conical shaft.

[0011] Furthermore, the pitches of the left-hand ball screw, the right-hand ball screw, the left-hand thread groove, and the right-hand thread groove are all the same. The nominal diameters of the threads of the left-hand ball screw and the right-hand ball screw are the same, and the nominal diameters of the grooves of the left-hand thread groove and the right-hand thread groove are the same.

[0012] Furthermore, the left bowstring passes sequentially through the left-hand threaded groove of the left bow wheel and the guide groove of the left-hand ball screw before being fixed to the left bow arm, and the right bowstring passes sequentially through the right-hand threaded groove of the right bow wheel and the guide groove of the right-hand ball screw before being fixed to the right bow arm.

[0013] Furthermore, the nominal diameter of the left-hand ball screw is smaller than the maximum diameter of the left bow wheel, and the nominal diameter of the right-hand ball screw is smaller than the maximum diameter of the right bow wheel.

[0014] Furthermore, both the left-hand and right-hand ball screws have a lubricating and wear-resistant layer on their mating surfaces with the nut. The lubricating and wear-resistant layer is a polytetrafluoroethylene coating or a titanium nitride coating.

[0015] The beneficial effects of this invention are as follows:

[0016] 1. This invention utilizes a large-diameter spiral groove with gradually increasing diameter at the tail ends of the left-hand and right-hand spiral grooves. By applying the torque formula M=F×L, and with the bow arm deformation torque remaining constant, the force F required for pulling is effectively reduced by increasing the lever arm L, achieving a force-saving effect in pulling. Moreover, the force-saving effect gradually increases with the pulling stroke, significantly reducing the strength requirements on the user. At the same time, this invention directly utilizes the elastic deformation of the bow arm to store energy, eliminating the need for an additional dedicated energy storage structure, avoiding the problem of energy storage structure performance degradation, ensuring long-term stable energy storage capacity, and simplifying the bow body structure, thus reducing manufacturing and maintenance costs.

[0017] 2. The synchronization adjustment mechanism of this invention integrates a synchronization ring and an adjustment component. When the left and right bow wheel assemblies are subjected to uneven forces and become asynchronous, the adjustment components on both sides approach and contact each other. The elastic deformation of the adjustment components achieves flexible buffering and self-synchronization adjustment, avoiding mechanical wear caused by rigid collisions. Alternatively, it can use interlocking teeth to force a consistent rotation speed, thereby avoiding uneven launching force that affects launching accuracy and user experience.

[0018] 3. This invention integrates the left-hand ball screw, the right-hand ball screw, and the bow wheel into a single unit, ensuring the synchronization and stability of the transmission. Furthermore, the consistent design of the pitch and nominal diameter allows for precise compensation of spatial position changes in the bowstring during traction, enabling the user to maintain the same spatial position during traction, thus improving the force application effect and operational comfort. The anti-slip buffer pad of the projectile positioning component provides elastic fixation of the projectile, preventing it from sliding during traction and ejection, while also acting as a buffer to reduce collision damage between the projectile and the projectile frame.

[0019] 4. The bowstring of the present invention is fixed to the bow arm after being guided by both the bow wheel thread groove and the ball screw guide groove. The nominal diameter of the ball screw is smaller than the diameter of the bow wheel, which further optimizes the lever arm structure, realizes secondary labor saving, and improves the overall labor saving effect. The lightweight alloy bullet frame and anti-slip grip take into account both structural strength and ease of operation, reducing the extra load during the pulling process. Attached Figure Description

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0021] Figure 1 This is a three-dimensional schematic diagram of this embodiment;

[0022] Figure 2 This is the front view of this embodiment;

[0023] Figure 3 This is a 3D schematic diagram of the left bow wheel assembly;

[0024] Figure 4 This is a 3D schematic diagram of the right bow wheel assembly;

[0025] Figure 5 This is a schematic diagram illustrating the effort-saving aspect of this embodiment.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1-Left bow wheel assembly; 2-Right bow wheel assembly; 3-Left bow wheel; 4-Left-hand ball screw; 5-Left-hand threaded groove; 6-Left bowstring; 7-Nut; 8-Right bow wheel; 9-Right-hand ball screw; 10-Right-hand threaded groove; 11-Right bowstring; 12-Shot frame; 13-Large diameter spiral groove; 14-Synchronizing ring; 15-Elastic rubber ring; 16-Shot; 17-Left bow arm; 18-Right bow arm.

[0028] Note: The accompanying drawings are for illustrative purposes only and are not intended to limit the specific dimensions and proportions of the present invention. The part numbers correspond to the structure of the specific embodiment to facilitate understanding of the technical solution. Detailed Implementation

[0029] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0030] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0031] like Figure 1-5As shown, a self-synchronizing, force-saving drive mechanism for a slingshot includes a symmetrically arranged left bow wheel assembly 1 and a right bow wheel assembly 2. The left bow wheel assembly 1 includes a left bow wheel 3 and a left-handed ball screw 4 integrally formed with the left bow wheel 3. The left bow wheel 3 has a left-handed threaded groove 5 for accommodating the left bowstring 6. The right bow wheel assembly 2 includes a right bow wheel 8 and a right-handed ball screw 9 integrally formed with the right bow wheel 8. The right bow wheel 8 has a right-handed threaded groove 10 for accommodating the right bowstring 11. Nuts 7 of both the left-handed ball screw 4 and the right-handed ball screw 9 are fixed to the bow body. The inner side wall of the nut 7 and the mating surface of the ball screw are provided with a lubricating and wear-resistant layer made of polytetrafluoroethylene to reduce transmission friction resistance.

[0032] One end of the left bowstring 6 is fixed to the left bow arm 17 by a buckle, or connected to the left bow arm by a pulley and then fixed to the bow body. The other end is fixed to one end of the right bowstring 11 by a weaving method. The other end of the right bowstring 11 is fixed to the right bow arm 18 by a buckle, or it can be connected to the right bow arm by a pulley and then fixed to the bow body. The tail ends of the left-hand threaded groove 5 and the right-hand threaded groove 10 are each provided with at least one large-diameter spiral groove 13. The diameter of the large-diameter spiral groove 13 gradually increases along the rotation direction of the bow wheel, and the direction of rotation is consistent with the direction of rotation of the threaded groove of the bow wheel. In this embodiment, the left bow wheel 3 and the right bow wheel 4 are both conical shafts. The small diameter section at the front end of the conical shaft is provided with a threaded groove, and the large diameter section at the tail end is provided with a large-diameter spiral groove 13.

[0033] The pitch of the left-hand ball screw 4, the right-hand ball screw 9, the left-hand thread groove 5, and the right-hand thread groove 10 are all set to 1-5mm. The nominal thread diameter of the left-hand ball screw 4 and the right-hand ball screw 9 is 5-20mm, and the nominal diameter of the left-hand thread groove 5 and the right-hand thread groove 10 is greater than 20mm. This ensures accurate spatial position compensation during bowstring traction and that the input force is less than the output force.

[0034] To achieve better labor saving, in this embodiment, the left bowstring 6 passes sequentially through the left-hand threaded groove 5 of the left bow wheel 3 and the guide groove of the left-hand ball screw 4 before being fixed to the left bow arm 17. The right bowstring 11 passes sequentially through the right-hand threaded groove 10 of the right bow wheel 8 and the guide groove of the right-hand ball screw 9 before being fixed to the right bow arm 18. Figure 5 As shown:

[0035] Assuming an input torque M, an input force F, and an actual required tension F0, when there is no force-saving mechanism, F = F0; when passing through this mechanism, the required force is calculated as follows:

[0036] The radii of the left-hand threaded groove, the large-diameter helical groove, and the left-hand ball screw are R1, R2, and R3, respectively.

[0037] According to M=F×L, after passing through the left-hand threaded groove, we know from M=F1×R1 that its output force F1=M / R1. When passing through the large-diameter helical groove, its F2=M / R2. When R1 is less than R2, it is obvious that F2 is less than F1, thus achieving the first labor saving. When passing through the helical groove of the left-hand ball screw, F3=M / R3. F3 is obviously greater than F2, thus achieving a smaller input force and a larger output force, thus achieving the second labor saving.

[0038] Alternatively, we can directly set F3=F0. After passing through the spiral groove of the left-hand spiral ball screw from the large-diameter spiral groove, its input force F2 is less than F3, that is, less than F0. Then, after entering the large-diameter spiral groove from the left-hand thread groove, its input force F1 is less than F2, which is much less than F0, thus achieving two-stage labor saving.

[0039] Both the left bow wheel 3 and the right bow wheel 8 have a synchronous adjustment mechanism coaxially welded to their ends. The synchronous adjustment mechanism includes a synchronous ring 14 and an elastic adjustment component. The synchronous ring is made of aluminum alloy, and the elastic adjustment component is an elastic rubber ring 15 that is circumferentially sleeved on the outer wall of the synchronous ring. The outer wall of the elastic rubber ring is coated with a ceramic wear-resistant coating. The elastic rubber rings of the two synchronous rings are arranged opposite each other and are in contact with each other.

[0040] A projectile positioning component is provided at the connection between the left bowstring 6 and the right bowstring 11. The projectile positioning component includes a projectile frame 12 and an anti-slip buffer pad. The projectile frame is made of lightweight aluminum alloy, and its outer wall is covered with a rubber anti-slip grip. The anti-slip buffer pad is made of silicone and is attached to the inner wall of the projectile frame. Its inner wall has arc-shaped anti-slip textures for elastic contact with the projectile 16 to prevent the projectile from sliding.

[0041] The working principle of this embodiment is as follows: When in use, the projectile 16 is placed in the projectile frame 12 of the projectile positioning component, and the anti-slip buffer pad elastically abuts against the projectile 16 to achieve positioning; when the user pulls the projectile positioning component forward, the left bowstring 6 and the right bowstring 11 respectively drive the left bow wheel 3 and the right bow wheel 8 to rotate, and the left-hand ball screw 4 and the right-hand ball screw 9 rotate synchronously around the fixed nut 7, driving the left bow arm 17 and the right bow arm 18 to elastically deform inward to achieve energy storage.

[0042] During the pulling process, the bowstring gradually enters the large-diameter spiral groove 13 as the bow wheel rotates, the lever arm gradually increases, and the pulling force gradually decreases, achieving the first labor saving. For example, if the nominal diameter of both the left and right spiral grooves is 30mm, while the nominal diameter of the large-diameter spiral groove is 60mm, then when the torque is the same, the labor saving is 1 / 2. In this embodiment, the left bowstring 6 passes through the left spiral groove 5 of the left bow wheel 3 and the guide groove of the left spiral ball screw 4 in sequence and is then fixed to the left bow arm 17. The right bowstring 11 follows... After passing through the right-hand threaded groove 10 of the right bow wheel 8 and the guide groove of the right-hand ball screw 9, it is fixed to the right bow arm 18. If the nominal diameters of the left-hand ball screw 4 and the right-hand ball screw 9 are both set to 10mm, and the nominal diameters of the left bow wheel 3 and the right bow wheel 8 are both 30mm, when the torque is the same, the input force is 1 / 3 of the output force, thus achieving secondary force saving. The total force saving is 1 / 2 * 1 / 3 = 1 / 6, that is, if a pulling force of 600N is required, only 100N is needed to pull.

[0043] If the left and right bow wheel assemblies are subjected to uneven forces and become asynchronous, the elastic rubber rings 14 of the two synchronization adjustment mechanisms will move closer to each other, and the elastic rubber rings will deform elastically upon contact, thereby achieving flexible self-synchronization adjustment and ensuring that the left and right bow arms 17 and 18 deform synchronously.

[0044] After the projectile positioning assembly is released, the elastic reaction force of the left bow arm 17 and the right bow arm 18 is released through the bowstring, driving the projectile 16 to be launched at high speed. Throughout the process, the energy is stored by the elastic deformation of the bow arm itself, without the performance degradation problem of an additional energy storage structure. Moreover, the one-piece molded bow wheel and ball screw, with consistent pitch and nominal diameter design, ensure the stability of transmission and the comfort of operation.

[0045] The variable diameter shaft of the present invention can also be a stepped shaft, the elastic adjustment component can also be a spring sheet group evenly distributed along the circumference of the synchronization ring, and the anti-slip buffer pad can also be made of foam material. All equivalent substitutions or modifications made under the concept of the present invention shall be included in the protection scope of the present invention.

[0046] Similarly, the synchronization adjustment mechanism in this embodiment can also adopt a meshing mechanism of two external gears, that is, including a synchronization ring 14 and an adjustment component. The adjustment component is a locking tooth fitted on the synchronization ring. The locking teeth on the two synchronization rings are arranged opposite to each other and form a locking engagement. Thus, when the two are subjected to uneven force and are not synchronized, the restriction of the two meshing teeth can achieve forced synchronization adjustment, ensure that the deformation of the left and right bow arms 17 and 18 is synchronized, maintain the stability of the projectile direction, and improve the hit rate and user experience.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A self-synchronizing, force-saving drive mechanism for a slingshot, characterized in that, The system includes symmetrically arranged left and right bow wheel assemblies. The left bow wheel assembly comprises a left bow wheel and a left-handed ball screw integrally formed with the left bow wheel. The left bow wheel has a left-handed threaded groove for accommodating the left bowstring. The right bow wheel assembly comprises a right bow wheel and a right-handed ball screw integrally formed with the right bow wheel. The right bow wheel has a right-handed threaded groove for accommodating the right bowstring. The nuts of both the left-handed and right-handed ball screws are fixedly connected to the bow body. One end of the left bowstring is fixed to the left bow arm, and the other end is fixedly connected to one end of the right bowstring. The other end of the right bowstring is fixed to the right bow arm. The tail ends of both the left-handed and right-handed threaded grooves have at least one turn. A large-diameter spiral groove is provided, the diameter of which gradually increases along the rotation direction of the bow wheel, and the spiral direction is consistent with the spiral direction of the threaded groove of the bow wheel. A synchronous adjustment mechanism is integrally provided on both the left and right bow wheels. The synchronous adjustment mechanism includes a synchronous ring and an adjusting component. The synchronous ring is coaxially fixed to the end of the bow wheel, and the adjusting component is detachably fixed to the synchronous ring. The two adjusting components maintain the same rotational speed of the two bow wheels through the resistance formed by their contact. A projectile positioning assembly is provided at the connection between the left and right bow strings. The projectile positioning assembly includes a projectile frame and an anti-slip buffer pad. The anti-slip buffer pad is located on the inner wall of the projectile frame for elastic contact with the projectile.

2. The self-synchronizing force-saving drive mechanism for a slingshot according to claim 1, characterized in that, The adjusting component is an elastic ring circumferentially arranged on the outer wall of the synchronization ring, and the two elastic rings are arranged to abut against each other.

3. The self-synchronizing, force-saving drive mechanism for a slingshot according to claim 1, characterized in that, The adjusting component is a locking tooth circumferentially arranged on the outer wall of the synchronizing ring, and the two locking teeth are meshed with each other.

4. The self-synchronizing force-saving drive mechanism for a slingshot according to claim 1, characterized in that, Both the left and right bow wheels are variable diameter shafts. The small diameter section at the front end of the variable diameter shaft has the left-hand threaded groove or the right-hand threaded groove, and the large diameter section at the rear end has the large diameter spiral groove. The variable diameter shaft is a stepped shaft or a conical shaft.

5. The self-synchronizing force-saving drive mechanism for a slingshot according to claim 1, characterized in that, The pitches of the left-hand ball screw, the right-hand ball screw, the left-hand thread groove, and the right-hand thread groove are all the same. The nominal diameters of the threads of the left-hand ball screw and the right-hand ball screw are the same, and the nominal diameters of the grooves of the left-hand thread groove and the right-hand thread groove are the same.

6. The self-synchronizing force-saving drive mechanism for a slingshot according to claim 1, characterized in that, The left bowstring passes through the left-hand threaded groove of the left bow wheel and the guide groove of the left-hand ball screw in sequence before being fixed to the left bow arm. The right bowstring passes through the right-hand threaded groove of the right bow wheel and the guide groove of the right-hand ball screw in sequence before being fixed to the right bow arm.

7. The self-synchronizing force-saving drive mechanism for a slingshot according to claim 1, characterized in that, The nominal diameter of the left-hand ball screw is smaller than the maximum diameter of the left bow wheel, and the nominal diameter of the right-hand ball screw is smaller than the maximum diameter of the right bow wheel.

8. The self-synchronizing force-saving drive mechanism for a slingshot according to claim 1, characterized in that, Both the left-hand and right-hand ball screws have a lubricating and wear-resistant layer on their mating surfaces with the nut. The lubricating and wear-resistant layer is a polytetrafluoroethylene coating or a titanium nitride coating.

Images