An adjustable bistable gripper with capture and ejection functions

Abstract

The application discloses a kind of adjustable bistable gripper with capture and eject function, belong to robot gripper technical field;A kind of adjustable bistable gripper with capture and eject function includes base, two sides of the upper end of base are respectively provided with one passive finger rod, the upper end of base is respectively rotatably connected with D type shaft, D type shaft penetrates passive finger rod and is fixedly connected with it;The lower end of each passive finger rod is provided with one active control rod, active control rod is rotatably adjusted and fixed on D type shaft, the upper end of passive finger rod is connected with active control rod with elastic ring, and elastic tension is applied between the upper end of passive finger rod and active control rod;Two described passive finger rods are installed with elastic band, the upper end of two passive finger rods is fixed with the both ends of elastic band respectively, the middle position of elastic band is fixed with clamping plate, and the lower end of clamping plate is fixed with active control rope.

Description

Technical Field

[0001] This invention belongs to the field of robot gripper technology, specifically relating to an adjustable bistable gripper with capture and ejection functions. Background Technology

[0002] A bistable structure is a structure that requires no external energy input in either its open or closed state. It has two minimum potential energy points, corresponding to its two stable positions. When a bistable mechanism is subjected to external energy input exceeding a certain energy barrier, it can jump from one minimum potential energy point to the other, exhibiting a steady-state jump. Currently, most bistable grippers only have a single active gripping mode, and multi-mode gripping serving multiple purposes in different working scenarios has not yet been realized. The response speed and sensitivity of existing bistable actuators to external stimuli during the initial design process mainly rely on their pre-set structural parameters, materials, and driving methods. Once the actuator is manufactured, its function and performance are unchangeable, resulting in limited applicability scenarios for the gripper. Therefore, a bistable gripper with adjustable trigger force is needed to replace traditional bistable grippers.

[0003] Currently, there has been some research on adjustable bistable grippers both domestically and internationally. For example, the Chinese invention patent CN113370239B improves the success rate of passively grasping targets with relatively low kinetic energy by dynamically adjusting the pre-displacement of the gripper to change the trigger energy barrier of the bistable soft gripper. However, it requires pre-adjustment and cannot be continuously adjusted. Another example is the paper published in the international journal IEEE, "Yonakang Jiang, Xin Tong, Jian Li, Chongjing Cao, Xing Gao, Yinatian Li. Reprogrammable Bistable Actuators for Multimodal Fast, and Ultrasensitive Grasping." This paper proposes a novel programmable bistable actuator that rapidly releases stored energy in an intermediate state before the structure reaches the instability edge. By programming the energy barrier of these intermediate states, the bistable actuator exhibits special functions and demonstrates its advantages in wave propagation, rapid capture, and precise grasping. However, the sensitivity adjustability of current programmable bistable actuators to external stimuli remains limited to a very small range. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide an adjustable bistable gripper with capture and ejection functions, thus solving the problems in the prior art.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] An adjustable bistable gripper with capture and ejection functions includes a base, with a passive finger rod on each side of the upper end of the base, and a D-shaped shaft rotatably connected to each side of the upper end of the base. The D-shaped shaft passes through the passive finger rod and is fixedly connected to it. An active control rod is provided at the lower end of each passive finger rod, and the active control rod is rotatably and adjustablely fixed on the D-shaped shaft. An elastic ring is connected between the upper end of the passive finger rod and the active control rod to apply an elastic tension between the upper end of the passive finger rod and the active control rod.

[0007] An elastic band is installed between the two passive finger rods. The two ends of the elastic band are fixed to the upper ends of the two passive finger rods respectively. A clamp is fixed in the middle of the elastic band, and an active control rope is fixed at the lower end of the clamp.

[0008] Furthermore, a bracket is fixed on the base, and the bracket is equipped with a rotatable drum, with one end of the active control rope wound around the drum.

[0009] Furthermore, a direct drive motor is installed on the base, and a gear is fixed on the output shaft of the direct drive motor. A clutch is installed between the gear and the drum. The gear can mesh with the external gear of the clutch. When the clutch is energized, the clutch output shaft rotates synchronously with the drum.

[0010] Furthermore, the D-shaped shaft passes through the active control rod, and the active control rod is threaded with a set screw, which can contact and abut against the D-shaped shaft.

[0011] Furthermore, the cross-section of the D-shaped shaft is D-shaped, and the set screw contacts the plane on the D-shaped shaft.

[0012] Furthermore, the upper ends of both passive finger rods are rotatably connected to optical axes, and the outer circular surface of the optical axes contacts the surface of the elastic band.

[0013] Furthermore, a pressure plate is fixed to the upper side of each of the two passive finger rods by bolts. The two pressure plates can press and fix the two ends of the elastic band to the two passive finger rods respectively.

[0014] Furthermore, a synchronous pulley is fixed on each of the D-shaped shafts located on both sides of the base, and a synchronous rope is installed between the two synchronous pulleys. The two ends of the synchronous rope are wrapped around the two synchronous pulleys respectively, and the two synchronous pulleys rotate synchronously in opposite directions.

[0015] Furthermore, a bushing is provided at the upper end of the passive finger rod, and the inner surface of one end of the elastic ring is in close contact with the bushing.

[0016] A robot comprising the aforementioned adjustable bistable gripper with capture and ejection capabilities.

[0017] The beneficial effects of this invention are:

[0018] 1. The adjustable bistable gripper of the present invention does not require the addition of fixed mechanical limits. The width of the opening can be controlled by adjusting the active control rope and the active control rod, thereby gripping objects of different sizes.

[0019] 2. When there is no object to grasp, the bistable gripper can switch between two stable states by adjusting the active control lever past the critical trigger position.

[0020] 3. During the release and clamping process of the bistable gripper, the passive finger lever can be brought closer to the critical trigger clamping position by adjusting the active control lever or by adjusting the active control rope to apply tension to the elastic band. This reduces the angular displacement of the passive finger lever to the critical trigger clamping position. In other words, compared to the unadjusted state, only a smaller triggering force is needed to make the gripper enter the clamping state, thus speeding up the gripper's capture speed.

[0021] 4. After the bistable gripper grasps the object, the active control rope is adjusted to give the elastic band a large rebound force. Then, the active control lever is adjusted past the critical release position so that the passive finger lever meets the release condition. The active control lever is then adjusted to approach the critical trigger release position. At this point, the trigger force is close to the maximum, and the tension of the elastic band on the passive finger lever is also close to the maximum. Once the clutch is de-energized, the rope is released, the passive finger lever is released instantly, and the elastic band is quickly taut, which accelerates the release speed of the elastic band and thus enhances the gripper's release capability. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a perspective view of the adjustable bistable gripper of the present invention;

[0024] Figure 2 This is a cross-sectional view of the adjustable bistable gripper of the present invention;

[0025] Figure 3 This is a cross-sectional view of the internal connecting member of the gripper of the present invention;

[0026] Figure 4 This is a diagram illustrating the adjustment strategy for adjusting the size of the gripper opening according to the present invention;

[0027] Figure 5This is a diagram illustrating the adjustment strategy of the gripper in this invention, which adjusts the triggering force of the gripper from closed to open.

[0028] Figure 6 This is a diagram illustrating the adjustment strategy of the gripper in this invention, which adjusts the triggering force of the gripper during the opening and closing process.

[0029] Figure 7 The present invention provides a strategy diagram for achieving rapid capture by adjusting the gripper's triggering force;

[0030] Figure 8 This is a diagram illustrating the adjustment strategy of the gripper in this invention, which enhances the ejection capability by adjusting the triggering force of the gripper.

[0031] Among them, 1-base; 2-direct drive motor; 3-pull plate; 4-set screw; 5-D-shaped shaft; 6-active control lever; 7-passive finger lever; 8-pressure plate; 9-shaft sleeve; 10-optical shaft; 11-elastic belt; 12-synchronous pulley; 13-screw; 14-active control rope; 15-elastic ring; 16-clutch; 17-bracket; 18-drum; 19-radial perforated shaft sleeve; 20-thermal melt nut; 21-washer; 22-bearing; 23-gear; 24-clamping plate; 25-synchronous rope. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] like Figures 1 to 2 As shown, an adjustable bistable gripper with capture and ejection functions includes a base 1. A passive finger rod 7 is respectively provided on both sides of the upper end of the base 1. D-shaped shafts 5 are rotatably connected to both sides of the upper end of the base 1. The D-shaped shafts 5 pass through the passive finger rods 7 and are fixedly connected to them, thereby forming a hinge between the passive finger rods 7 and the base 1. An active control rod 6 is provided at the lower end of each passive finger rod 7. The active control rod 6 is fixed to the D-shaped shaft 5. A bushing 9 is provided at the upper end of the passive finger rod 7. An elastic ring 15 is connected between the bushing 9 and the active control rod 6 to apply an elastic tension between the upper end of the passive finger rod 7 and the active control rod 6.

[0034] In this embodiment, the D-shaped shaft 5 passes through the active control rod 6. The cross-section of the D-shaped shaft 5 is D-shaped (i.e., there is a plane on the outer circular surface). By screwing the set screw 4 into the active control rod 6, the set screw 4 can contact and abut against the plane of the D-shaped shaft 5, thereby realizing the active control rod 6 being rotatably and adjustablely fixed on the D-shaped shaft 5.

[0035] An elastic band 11 is installed between the two passive finger rods 7. The two ends of the elastic band 11 are fixed to the upper ends of the two passive finger rods 7 respectively. A clamping plate 24 is fixed in the middle of the elastic band 11. An active control rope 14 is fixed at the lower end of the clamping plate 24. By applying a downward pulling force through the active control rope 14, the two passive finger rods 7 can be flipped and brought closer together, and the object can be clamped.

[0036] A direct drive motor 2 and a drum 18 are provided on the base 1. One end of the active control rope 14 is wound on the drum 18. The direct drive motor 2 can drive the drum 18 to rotate, thereby applying a downward pulling force to the active control rope 14 and releasing the active control rope 14.

[0037] In this embodiment, a bracket 17 is fixed on the base 1, and a drum 18 is rotatably connected to the bracket 17. A gear 23 is fixed on the output shaft of the direct drive motor 2, and a clutch 16 is installed between the gear 23 and the drum 18. The gear 23 can mesh with the external gear of the clutch 16. When the clutch is energized, the clutch output shaft rotates synchronously with the drum 18, thereby transmitting the rotational torque of the direct drive motor 2 to the drum 18. By introducing the clutch 16, the control of the active control rope 14 is realized, thereby achieving different functions. When the clutch is energized, the drum 18 controls the active control... The control rope 14 applies tension, causing the active control rope 14 to pull the elastic band 11, which in turn controls the opening size or rotation angle of the passive finger lever 7, thereby affecting the amount of force required to move from the initial state to the clamping state. When the ejection function of the gripper is required, the active control rope 14 first pulls the elastic band 11, which is wrapped around the gripper, to near the upper surface of the base 1, and the active control lever 6 is adjusted to pass the critical clamping position, so that the gripper is in the released state. Then, the clutch 16 is de-energized, so that the active control rope 14 loses the tension applied by the drum 18, thereby ejecting the gripper.

[0038] In this embodiment, a pull plate 3 is provided on the base 1, which is used to fix the direct drive motor 2. The direct drive motor 2 includes an encoder 201, a motor 202 and a transmission system 203. After the encoder 201 is started, the motor 202 starts to work and provides power to the transmission system 203, and the output shaft of the direct drive motor 2 starts to rotate. The two direct drive motors 2 on the outside of the base 1 directly control the active control lever 6 and control the angle of the active control lever 6. The output shaft of the direct drive motor 2 on the inside of the base 1 is connected to the gear 23. A certain gap is left between the gear 23 and the side wall inside the base to avoid friction. The gear 23 drives the clutch 16 that is engaged with it and energized. The clutch 16 drives the drum 18 on the bracket 17 through the connected D-shaped shaft 5. The drum 18 is also connected to the D-shaped shaft 5. The drum 18 drives the active control rope 14 fixed on it. The active control rope 14 tightens or loosens the elastic band 11 as the drum 18 rotates forward and backward, thereby controlling the opening and closing of the passive finger lever 7.

[0039] In this embodiment, the upper ends of the two passive finger rods 7 are rotatably connected to optical shafts 10, and the outer circular surface of the optical shafts 10 contacts the surface of the elastic band 11 to reduce frictional damage between the elastic band 11 and the passive finger rods 7. In addition, a pressure plate 8 is fixed to the upper side of each of the two passive finger rods 7, and the two pressure plates 8 can press and fix the two ends of the elastic band 11 to the two passive finger rods 7 respectively. The pressure plate 8 and the passive finger rods 7 are detachably fixed by bolts 13, which facilitates the disassembly and replacement of the elastic band 11 in the future.

[0040] In addition, it is worth mentioning that a synchronous pulley 12 is fixed on the D-shaped shaft 5 on both sides of the base 2, and a synchronous rope 25 is installed between the two synchronous pulleys 12. The two ends of the synchronous rope 25 are respectively wrapped around the two synchronous pulleys 12, and when one of the synchronous pulleys 12 rotates, the other synchronous pulley 12 rotates synchronously in the opposite direction.

[0041] like Figure 3 As shown, in this embodiment, the D-shaped shaft 5 is rotatably connected to the base 1 via the bearing 22; the shim 21 is fitted onto the D-shaped shaft 5 and abuts against the inner ring of the bearing 22 for positioning, so that there is a certain gap between the passive finger rod 7 and the base 1, avoiding friction between the passive finger rod 7 and the base; the D-shaped shaft 5 is fixedly connected to the passive finger rod 7 via the radially perforated bushing 19. Specifically, the hot melt nut 20 is heated with a soldering iron and then inserted into the hole of the radially perforated bushing 19. The radially perforated bushing 19 with the hot melt nut 20 is then engaged with the passive finger rod 7. Finally, the set screw 4 passes through the passive finger rod 7 and connects with the hot melt nut 20, and then presses against the D-shaped shaft 5 to achieve a fixed connection.

[0042] Working principle:

[0043] The adjustment strategy diagram for adjusting the opening size of the gripper in this embodiment is shown below. Figure 4 As shown:

[0044] 1. Maximum Opening State: Rotate the active control lever 6 to near the critical trigger clamping position. At this point, the tension of the elastic ring 15 on the passive finger lever 7 in the release direction is close to its maximum. Loosen the active control rope 14 to... Figure 4 The position of the maximum opening state minimizes the tension on the elastic band 11, thereby increasing the opening released by the passive finger lever 7, which allows it to grasp objects of the corresponding size of the opening.

[0045] II. Adjusted opening state: When the opening is too large, it will be unable to wrap around objects with a relatively smaller opening. In this case, it is necessary to first adjust the active control lever 6 so that it passes the critical trigger clamping position, thereby reducing the tension of the elastic ring 15 on the passive finger lever 7. Then, adjust the active control rope 14 to shorten the rope length, making the opening of the passive finger lever 7 smaller. At this time, it is possible to grab objects with a relatively smaller opening.

[0046] 3. Opening and closing state: Adjust the active control rope 14 to continue to contract the rope length, pull the elastic band 11 to drive the passive finger rod 7 into the opening and closing state.

[0047] The adjustment strategy of the gripper in this embodiment, which adjusts the triggering force of the gripper from closed to open, is shown in the diagram below. Figure 5 As shown:

[0048] 1. Clamping state: Position the active control lever 6 to the right of the critical trigger release position, and the gripper is in a clamping state.

[0049] 2. Adjusting the release state of the active control lever 6: By adjusting the active control lever 6 to pass the critical trigger release position, the passive finger lever 7 is pulled by the release direction of the elastic ring 15. At this time, the synchronous wheel 12, which rotates in the same direction as the passive finger lever 7, starts to rotate and drives the synchronous rope 25 to release the other passive finger lever 7 in sync, thereby opening the gripper.

[0050] Adjusting the release state of the active control rope 14: First, adjust the active control lever 6 to the critical trigger release position. Then, by releasing the length of the active control rope 14, the tension of the passive finger lever 7 on the active control rope 14 decreases, causing the passive finger lever 7 to pass the critical trigger release position. At this time, the synchronous wheel 12, which rotates with the passive finger lever 7, begins to rotate and drives the synchronous rope 25 to make the other passive finger lever 7 synchronously pass the critical release position, thus opening the gripper.

[0051] The adjustment strategy of the gripper in this embodiment, which adjusts the triggering force of the gripper from the opening to the closing process, is shown in the diagram below. Figure 6 As shown:

[0052] 1. Release state: Position the active control lever 6 to the left of the critical trigger release position, and the gripper is in the release state.

[0053] II. Control lever clamping state: By adjusting the active control lever 6 past the critical trigger clamping position, the passive finger lever 7 is pulled by the clamping direction of the elastic ring 15. At this time, the synchronous wheel 12, which rotates in the same direction as the passive finger lever 7, starts to rotate and drives the synchronous rope 25 to clamp the other passive finger lever 7 synchronously, thereby closing the gripper.

[0054] Adjusting the active control rope clamping state: First, adjust the active control lever 6 to the critical trigger clamping position. Then, by contracting the length of the active control rope 14, the passive finger lever 7 experiences increased tension from the active control rope 14, causing the passive finger lever 7 to pass the critical trigger clamping position. At this time, the synchronous pulley 12, which rotates in sync with the passive finger lever 7, begins to rotate and drives the synchronous rope 25 to cause the other passive finger lever 7 to synchronously pass the critical clamping position, thus closing the gripper.

[0055] The adjustment strategy diagram for the gripper in this embodiment, which achieves rapid capture by adjusting the gripper's trigger force, is shown below. Figure 7 As shown:

[0056] The process of changing the trigger clamping force by adjusting the active control lever is as follows: Figure 7 As shown in (a):

[0057] 1. Initial state: The active control lever 6 is moved past the critical trigger release position, the passive finger is in the release state, and the distance between the grasped object and the position where the elastic band 11 is pulled by the active control rope is 10-20mm. The grasped object is a cylinder or a pentagon.

[0058] 2. Reduced triggering force state: Rotate the active control lever 6 counterclockwise to bring it close to the critical triggering clamping position. At this time, the force required to trigger the gripper is close to the minimum. Release the gripped object, and its own weight G acts on the elastic band. At this time, the weight G is greater than the force required for the gripper to trigger clamping.

[0059] III. Clamping State: Since the gravity G is greater than the force required to trigger clamping by the gripper, the passive finger rod 7 is pulled by the elastic ring 15 in the clamping direction. At this time, the synchronous wheel 12, which rotates in the same direction as the passive finger rod 7, starts to rotate and drives the synchronous rope 25 to clamp the other passive finger rod 7 synchronously. The gripper enters the clamping state, and the grasped object is wrapped by the elastic band 11.

[0060] The process of changing the force that triggers the clamping by adjusting the active control rope is as follows: Figure 7 As shown in (b):

[0061] 1. Initial state: The active control rope passes the critical trigger release position, the passive finger is in the release state, and the distance between the grasped object and the position where the elastic band is pulled by the active control rope is 10-20mm. The grasped object is a cylinder or a five-pointed star.

[0062] 2. Reduced triggering force state: Contract the length of the active control rope 14 to bring the passive finger rod 7 close to the critical triggering clamping position. At this time, the force of the gripper is reduced, the gripped object is released, and its own weight G acts on the elastic band. At this time, the weight G is greater than the force required for the gripper to trigger clamping.

[0063] III. Clamping State: Since the gravity G is greater than the force required to trigger clamping by the gripper, the passive finger rod 7 is pulled by the elastic ring 15 in the clamping direction. At this time, the synchronous wheel 12, which rotates in the same direction as the passive finger rod 7, starts to rotate and drives the synchronous rope 25 to clamp the other passive finger rod 7 synchronously. The gripper enters the clamping state, and the grasped object is wrapped by the elastic band 11.

[0064] The adjustment strategy of enhancing the ejection capability of the gripper in this embodiment is shown in the diagram below. Figure 8 As shown:

[0065] 1. Initial state: The active control lever 6 is positioned beyond the critical trigger clamping position, the length of the active control rope 14 is the initial length L, the passive finger is in the clamping state, and the grasped object is wrapped by the elastic band 11.

[0066] 2. Pre-ejection state: First, adjust the active control rope 14 to its length L, then adjust the active control lever 6 until the length of the elastic band 15 reaches L. When the active control lever 6 passes the critical trigger release position, the passive finger lever 7 reaches the release condition. However, since the active control lever 6 is far from the critical trigger release position (the trigger release force is small), the force released by the passive finger lever 7 is small. Also, since the tension of the active control rope 14 on the elastic band 11 is greater than the force released by the passive finger lever, the gripper is still in the clamping state at this time.

[0067] 3. Adjusting the trigger force: Adjust the active control lever 6 to be close to the critical trigger release position, so that the length of the elastic coil 15 reaches L' release. At this time, the tension of the elastic coil 15 on the passive finger lever 7 is close to the critical trigger release force. By comparing L release and L' release, it is clear that L' release is greater than L release. This is because the longer the elastic coil 15 is stretched, the greater the tension it exerts on the passive finger lever 7. Compared to the trigger energy required by the passive finger lever 7 when it is not adjusted, more energy can be obtained at this time to make the passive finger lever 7 release faster. Moreover, the faster release of the passive finger lever 7 can make the elastic band 11 taut more quickly, giving the grasped object an additional thrust, thereby making the grasped object bounce farther and avoiding contact with the passive finger lever 7 during the bounce.

[0068] IV. Ejection State: After the bistable gripper grasps the object, the active control rope 14 is adjusted to give the elastic band 11 a large rebound force. Then, the active control lever 6 is adjusted past the critical release position so that the passive finger lever 7 meets the release condition. The active control lever 6 is further adjusted and brought closer to the critical trigger release position. At this time, the trigger force is close to the maximum, and the tension of the elastic ring 15 on the passive finger lever 7 is also close to the maximum. Once the clutch 16 is de-energized, the rope is released, the passive finger lever 7 is released instantly, and the elastic band 11 is quickly taut, which accelerates the ejection speed of the elastic band 11, thereby enhancing the ejection capability of the gripper.

[0069] In this embodiment, the component states of the gripper that enhance the ejection capability by adjusting the gripper's trigger force are shown in the table below:

[0070] Table 1. Parts Status Table for Enhancing Ejection Capability by Adjusting the Grappling Force

[0071]

[0072]

[0073] In summary:

[0074] For a bistable gripper where the trigger force cannot be adjusted, a fixed force and displacement distance are required to achieve the capture capability. However, this embodiment reduces the displacement distance of the passive finger lever to trigger and the force required to trigger by adjusting the trigger force. A smaller required trigger force and a shorter required trigger displacement mean that the steady-state switching speed will be faster, which greatly improves the capture capability of the bistable gripper.

[0075] For ejector grippers where the trigger force cannot be adjusted, the ejection capability (ejection capability is the displacement distance after the gripper ejects the grasped object) is mainly changed by altering its structure, the material of the elastic element, or the stroke of the elastic element during pre-ejection. In this embodiment, by adjusting the trigger force (adjusting the position of the active control lever near the critical trigger release), the release force of the passive finger lever can be increased when the stroke of the elastic element during pre-ejection reaches its maximum position. This adds an elastic force from the opening of the passive finger lever when the grasped object is ejected, increasing the gripper's range over the grasped object, thus enhancing the gripper's ejection capability. The above improvements enrich the operational range of the bistable gripper.

[0076] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0077] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. An adjustable bistable gripper with capture and ejection functions, comprising a base (1), characterized in that, A passive finger rod (7) is provided on each side of the upper end of the base (1). A D-shaped shaft (5) is rotatably connected to each side of the upper end of the base (1). The D-shaped shaft (5) passes through the passive finger rod (7) and is fixedly connected to it. An active control rod (6) is provided at the lower end of each passive finger rod (7). The active control rod (6) is rotatably and adjustablely fixed on the D-shaped shaft (5). An elastic ring (15) is connected between the upper end of the passive finger rod (7) and the active control rod (6) to apply an elastic tension between the upper end of the passive finger rod (7) and the active control rod (6). An elastic band (11) is installed between the two passive finger rods (7). The two ends of the elastic band (11) are fixed to the upper ends of the two passive finger rods (7), and a clamp (24) is fixed in the middle of the elastic band (11). An active control rope (14) is fixed at the lower end of the clamp (24). A bracket (17) is fixed on the base (1), and the bracket (17) is equipped with a rotatable drum (18). One end of the active control rope (14) is wound around the drum (18). A direct drive motor (2) is installed on the base (1). A gear (23) is fixed on the output shaft of the direct drive motor (2). A clutch (16) is installed between the gear (23) and the drum (18). The gear (23) can mesh with the external gear of the clutch (16). When the clutch is energized, the output shaft of the clutch (16) rotates synchronously with the drum (18).

2. The adjustable bistable gripper with capture and ejection functions according to claim 1, characterized in that, The D-shaped shaft (5) passes through the active control rod (6), and the active control rod (6) is threaded with a set screw (4), which can contact and abut against the D-shaped shaft (5).

3. The adjustable bistable gripper with capture and ejection functions according to claim 2, characterized in that, The cross-section of the D-shaped shaft (5) is D-shaped, and the set screw (4) is in contact with the plane on the D-shaped shaft (5).

4. The adjustable bistable gripper with capture and ejection functions according to claim 1, characterized in that, The upper ends of the two passive finger rods (7) are rotatably connected to optical shafts (10), and the outer circular surface of the optical shafts (10) is in contact with the surface of the elastic band (11).

5. An adjustable bistable gripper with capture and ejection functions according to claim 1 or 4, characterized in that, The upper ends of the two passive finger rods (7) are respectively fixed with a pressure plate (8) by bolt connection. The two pressure plates (8) can press and fix the two ends of the elastic band (11) onto the two passive finger rods (7).

6. The adjustable bistable gripper with capture and ejection functions according to claim 1, characterized in that, A synchronous pulley (12) is fixed on each of the D-shaped shafts (5) on both sides of the base (1). A synchronous rope (25) is installed between the two synchronous pulleys (12). The two ends of the synchronous rope (25) are wrapped around the two synchronous pulleys (12) respectively, and the two synchronous pulleys (12) rotate synchronously in opposite directions.

7. An adjustable bistable gripper with capture and ejection functions according to claim 1, characterized in that, The upper end of the passive finger rod (7) is provided with a bushing (9), and the inner surface of one end of the elastic ring (15) is in close contact with the bushing (9).

8. A robot, characterized in that, Includes the adjustable bistable gripper with capture and ejection functions as described in any one of claims 1-7.

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