Manipulator with movable metacarpal bone mechanism
By designing a robotic hand with a movable metacarpal mechanism, and using an electrically controlled telescopic rod and a wrist transverse arch mechanism to simulate the movement of the human hand metacarpal bones, the problem of insufficient flexibility and stability of existing bionic dexterous hands when grasping complex or large-sized targets has been solved, and efficient grasping and stable clamping of different targets has been achieved.
Patent Information
- Application Number
- CN202511326421.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-17
- Publication Date
- 2025-11-28
AI Technical Summary
Existing bionic dexterous hands generally adopt a fixed palm structure, lacking coordinated movement between the palm and fingers, resulting in insufficient flexibility and stability when grasping complex or large objects.
Design a robotic hand with a movable metacarpal bone mechanism. Through the coordinated action of an electrically controlled telescopic rod, a vertical main shaft, a main drive ring block, a pull rope, and a secondary drive ring block, the mechanical phalanges can rotate along the longitudinal arch direction, and the transverse wrist arch mechanism realizes the lateral opening and closing of the mechanical phalanges, simulating the coordinated movement of the human hand metacarpal bones.
It improves the robot's enveloping ability and gripping stability under different target shapes, enhances its adaptability to targets of different sizes, reduces impact and noise during opening and closing, and improves service life and the smoothness of the gripping process.
Smart Images
Figure CN121018623A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of mechanical hands, in particular to a mechanical hand with movable metacarpal mechanism. BACKGROUND
[0002] With the continuous development of robot technology, bionic dexterous hands gradually become an important research direction in the field of intelligent robots, service robots, rehabilitation medical robots and industrial automation. Most of the existing bionic dexterous hands adopt multi-degree-of-freedom driving mode, which can realize the bending, stretching and to some extent the grasping action of the fingers, and part of the structure can also simulate the pinching, grasping and rotating operation of the human hand. However, from the analysis of the biomechanical structure of the human hand, the movement of the human hand not only depends on the independent bending and stretching of the finger joints, but also depends on the coordinated cooperation of the whole palm, especially the linkage activity of the metacarpal and wrist, which plays a key role in grasping and operating.
[0003] In the actual grasping process, the human hand can realize the adduction, abduction and longitudinal arch and transverse arch deformation of the palm through the coupling of the palm muscles and joints, so that the overall shape of the palm changes, thereby better adapting to the shape and size of the target object. This flexible coordinated movement of the palm greatly improves the stability and adaptability of grasping. However, most of the existing bionic dexterous hands focus on the independent driving of the fingers, and generally adopt a fixed palm structure, i.e. the metacarpal part is designed as a rigid immovable unit, and only relies on the driving of the finger joints to complete clamping and pinching. Although this design can complete the basic grasping task, it lacks the movability of the palm, limiting the space envelope and cooperative ability between the fingers. When facing complex curved surfaces, irregular objects or large size workpieces, it is difficult for the fingers to form a reasonable angle relationship, and some fingers may not be able to effectively contact the target object, resulting in insufficient grasping force and stability. For example, when grasping a large size cylinder, if only relying on the movement of the finger joints, due to the fixed palm, the ring finger and little finger often cannot adhere to the surface of the object with the expansion of the palm, causing uneven distribution of the grasping points, and the overall grasping efficiency is significantly reduced. Similar problems also exist in the process of grasping plate-shaped objects, special-shaped parts and flexible objects, and the fixed palm structure often leads to insufficient grasping adaptability, which cannot meet the stable clamping requirements in complex operating environment. SUMMARY
[0004] (I) Technical problems solved
[0005] In view of the shortcomings of the prior art, the present application provides a mechanical hand with movable metacarpal mechanism, which solves the problem that the existing bionic dexterous hand generally adopts a fixed palm structure, lacks coordinated movement of the palm and fingers, and has insufficient flexibility and stability when grasping complex or large size target objects.
[0006] (II) Technical solutions
[0007] To achieve the above object, the present application provides the following technical scheme:
[0008] A mechanical hand with movable metacarpal mechanism, comprising: a main frame for providing a support frame; a metacarpal mechanism arranged on the main frame; a mechanical phalanx arranged on the metacarpal mechanism; a wrist transverse arch mechanism arranged on the main frame, the mechanical phalanx is provided with three, one of which is connected to the metacarpal mechanism, the other two are connected to the wrist transverse arch mechanism, the wrist transverse arch mechanism is used for transverse opening and closing of the two mechanical phalanges, and the mechanical phalanges are used for grabbing workpieces; the metacarpal mechanism comprises an electric control telescopic rod one, the electric control telescopic rod one is fixedly connected to the inner wall of the main frame, the output shaft of the electric control telescopic rod one is connected with a vertical main shaft, the bottom of the vertical main shaft is fixedly connected with a main drive ring block, the bottom of the main frame is fixedly connected with a hollow column, the side wall of the main frame is hinged with a phalanx connecting frame, the side of the phalanx connecting frame close to the hollow column is fixedly connected with a secondary drive ring block, the secondary drive ring block and the main drive ring block are connected with a pull rope, and the pull rope penetrates the inner wall of the hollow column; the wrist transverse arch mechanism comprises a bidirectional telescopic push rod and a transverse arch block, the transverse arch block is provided with two, the two transverse arch blocks are symmetrically hinged to the bottom of the main frame, one side of the transverse arch block is hinged with the bidirectional telescopic push rod, and the other side of the transverse arch block is hinged with the output shaft of the bidirectional telescopic push rod, the phalanx connecting frame is provided with three, the phalanx connecting frame is hinged to the two transverse arch blocks, the hinged points of the phalanx connecting frame are provided with vortex springs, which are used for keeping the horizontal state of the phalanx connecting frame under the action of no external force, and the middle shell of the bidirectional telescopic push rod is slidably connected to the main frame, so as to keep the two transverse arch blocks in a straight line position when driving relative movement.
[0009] Preferably, a connecting sleeve is arranged between the output shaft of the electric control telescopic rod one and the vertical main shaft, and a motor fixing seat is arranged on the inner wall of the main frame, which is used for stably connecting the electric control telescopic rod one.
[0010] Preferably, a guide sleeve is arranged on the vertical main shaft, which is used for ensuring the stability of the vertical main shaft in the process of linear motion and avoiding deviation.
[0011] Preferably, a limiting block is arranged at the hinged point between the phalanx connecting frame and the main frame, which is used for limiting the maximum swing angle of the phalanx connecting frame.
[0012] Preferably, a vortex spring is arranged at the junction of the phalanx connecting frame and the main frame, which is used for quickly restoring the phalanx connecting frame to the initial position when there is no motor driving.
[0013] Preferably, a buffer bushing is arranged on the transverse arch block, which is used for reducing the impact and noise when the transverse arch block is opened and closed.
[0014] Preferably, the outer wall of the main driving ring block is provided with a rope groove matched with the pull rope, and the inner wall of the hollow column is provided with a pull rope guide hole.
[0015] Preferably, the outer edge of the auxiliary driving ring block is provided with a clamping groove matched with the pull rope, and the two ends of the phalanx connecting frame are connected with the main frame through a hinge pin.
[0016] Preferably, the transverse arch block is provided with a reinforcing rib, and the transverse arch block and the main frame are hingedly connected through a pin shaft.
[0017] (Three) beneficial effects
[0018] Compared with the prior art, the mechanical hand with movable metacarpal mechanism provided by the application has the following beneficial effects:
[0019] 1. The mechanical hand with movable metacarpal mechanism sets the mechanical phalanges installed on the phalanx connecting frame to not only have a bending gripping function, but also to rotate as a whole along the longitudinal arch direction under the cooperation of the electric control telescopic rod, the vertical main shaft, the main driving ring block, the pull rope and the auxiliary driving ring block, and drive three mechanical phalanges to bend, so as to simulate the longitudinal arch movement of the human metacarpal bone, effectively improve the enveloping ability and gripping stability of the mechanical hand under different target object shapes.
[0020] 2. The mechanical hand with movable metacarpal mechanism sets the wrist transverse arch mechanism, drives two transverse arch blocks to symmetrically open and close through the bidirectional telescopic push rod, drives two phalanx connecting frames hingedly connected thereto to realize transverse opening and closing, adjusts the included angle between the two mechanical phalanges according to the size of the target object, and enhances the adaptability to different size target objects. At the same time, the transverse arch block is provided with a buffer bushing, which effectively reduces the impact and noise in the opening and closing process, improves the service life of the wrist transverse arch mechanism and the stability of the gripping process. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 It is a structural schematic diagram of the whole application;
[0022] Figure 2 It is a structural schematic diagram of the metacarpal mechanism of the application;
[0023] Figure 3 It is a structural schematic diagram of the wrist transverse arch mechanism of the application;
[0024] Figure 4 It is a structural schematic diagram of the transverse arch block of the application;
[0025] Figure 5 It is a structural schematic diagram of the pull rope between the auxiliary driving ring block and the main driving ring block of the application.
[0026] In the figure: 1, main frame; 2, metacarpal mechanism; 21, electric control telescopic rod one; 22, vertical main shaft; 23, main drive ring block; 24, hollow column; 25, phalanx connecting frame; 26, auxiliary drive ring block; 3, mechanical phalanx; 4, wrist transverse arch mechanism; 41, bidirectional telescopic push rod; 42, transverse arch block. DETAILED DESCRIPTION
[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.
[0028] Please refer to Figures 1-5 A mechanical hand with movable metacarpal mechanism comprises: a main frame 1 for providing a support frame; a metacarpal mechanism 2 arranged on the main frame 1; a mechanical phalanx 3 arranged on the metacarpal mechanism 2; and a wrist transverse arch mechanism 4 arranged on the main frame 1, wherein the mechanical phalanx 3 is provided with three, one of which is connected to the metacarpal mechanism 2, and the other two are connected to the wrist transverse arch mechanism 4, the wrist transverse arch mechanism 4 is used for transversely opening and closing the two mechanical phalanges 3, and the mechanical phalanges 3 are used for grabbing;
[0029] The metacarpal mechanism 2 comprises an electric control telescopic rod one 21 fixedly connected to the inner wall of the main frame 1, an output shaft of the electric control telescopic rod one 21 is connected with a vertical main shaft 22, the bottom of the vertical main shaft 22 is fixedly connected with a main drive ring block 23, the bottom of the main frame 1 is fixedly connected with a hollow column 24, the sidewall of the main frame 1 is hingedly connected with a phalanx connecting frame 25, one side of the phalanx connecting frame 25 close to the hollow column 24 is fixedly connected with an auxiliary drive ring block 26, the auxiliary drive ring block 26 and the main drive ring block 23 are connected with a pull rope, and the pull rope penetrates through the inner wall of the hollow column 24.
[0030] The wrist transverse arch mechanism 4 comprises a bidirectional telescopic push rod 41 and two transverse arch blocks 42, which are symmetrically hinged to the bottom of the main frame 1. One side of the transverse arch block 42 is hinged to the bidirectional telescopic push rod 41, and the other side of the transverse arch block 42 is hinged to the output shaft of the bidirectional telescopic push rod 41. Three phalanx connecting frames 25 are provided, and each of the two transverse arch blocks 42 is hinged to a phalanx connecting frame 25. The hinge point of the phalanx connecting frame 25 is provided with a volute spring for maintaining the horizontal state of the phalanx connecting frame 25 under no external force. The middle shell of the bidirectional telescopic push rod 41 is slidingly connected to the main frame 1, and is used to keep the two transverse arch blocks 42 in a straight line position when they are driven to move relative to each other, so as to avoid random rotation of the two transverse arch blocks 42. When the electric control telescopic rod 21 is started, the output shaft drives the main drive ring block 23 to move linearly through the vertical main shaft 22. The main drive ring block 23 pulls the auxiliary drive ring block 26 through the pull rope. Since the pull rope penetrates the inner wall of the hollow column 24, the auxiliary drive ring block 26 drives the phalanx connecting frame 25 fixed thereon to rotate around the hinge point of the side wall of the main frame 1 under the action of tension. In this way, the mechanical phalanx 3 installed on the phalanx connecting frame 25 can not only bend, but also rotate as a whole in the longitudinal arch direction, thereby realizing the effect similar to the movement of the human metacarpal bone in the longitudinal arch direction. At this time, the mechanical phalanx 3 on the metacarpal mechanism 2 becomes a longitudinal reference point. At the same time, when the bidirectional telescopic push rod 41 acts, one end thereof is hinged to one side of the transverse arch block 42, and the output shaft of the other end is hinged to the other side of the transverse arch block 42. With the extension and retraction of the bidirectional telescopic push rod 41, the two transverse arch blocks 42 make symmetrical opening and closing movements around the hinge points with the bottom of the main frame 1. The two transverse arch blocks 42 drive the two phalanx connecting frames 25 respectively, so that the two mechanical phalanxes 3 installed on the two phalanx connecting frames 25 open and close transversely. In this way, the mechanical phalanx 3 can adjust the opening and closing size under the driving action of the metacarpal mechanism 2, and can adjust the opening and closing size of the two mechanical phalanxes 3 under the transverse movement action of the wrist transverse arch mechanism 4. When the three mechanical phalanxes 3 are in the initial parallel position, the mechanical hand as a whole keeps an open posture. When the electric control telescopic rod 21 drives the main drive ring block 23 to drive the auxiliary drive ring block 26 and the phalanx connecting frame 25 thereon to rotate, a specific included angle is formed between the mechanical phalanx 3 on the metacarpal mechanism 2 and the other two mechanical phalanxes 3 driven by the wrist transverse arch mechanism 4. The three-fingered dexterous hand can adjust the spatial envelope posture according to the shape of the target object, and realize stable grasping. When the bidirectional telescopic push rod 41 further drives the transverse arch blocks 42 to open and close, the two transversely distributed mechanical phalanxes 3 open and close in the wrist transverse arch direction, thereby changing the included angle with the longitudinal reference mechanical phalanx 3.
[0031] The output shaft of the electric control telescopic rod one 21 is provided with a connecting sleeve between the output shaft and the vertical main shaft 22, to ensure stable connection between the output shaft of the electric control telescopic rod one 21 and the vertical main shaft 22, avoid looseness or eccentricity caused by direct connection, improve transmission accuracy, and the inner wall of the main frame 1 is provided with a motor fixing seat for stable connection of the electric control telescopic rod one 21, to strengthen the fixation of the electric control telescopic rod one 21 in the main frame 1, avoid vibration or displacement of the electric control telescopic rod one 21 during work, and thus improve overall stability. The vertical main shaft 22 is provided with a guide sleeve, to ensure the stability of the vertical main shaft 22 during linear motion, avoid main shaft deviation caused by lateral force or installation error, ensure the stability of the vertical main shaft 22 during linear motion, avoid deviation, make transmission smoother, reduce wear, and improve the service life and accuracy of the mechanical hand.
[0032] The hinge point between the phalange connecting frame 25 and the main frame 1 is provided with a limiting block to limit the maximum swing angle of the phalange connecting frame 25 relative to the main frame 1, to limit the maximum swing angle of the phalange connecting frame 25, avoid excessive rotation to cause part interference or damage, and ensure that the movement range of the mechanical phalange 3 is within a safe range.
[0033] The junction between the phalange connecting frame 25 and the main frame 1 is provided with a volute spring, to restore the phalange connecting frame 25 to the initial position when there is no motor driving, quickly restore the phalange connecting frame 25 to the initial position when the motor stops driving, ensure accurate reset, and improve the continuity and reliability of the mechanical hand action.
[0034] The transverse arch block 42 is provided with a buffer bushing installed at the transverse arch block 42, to absorb impact force during opening and closing movement, reduce impact and noise during transverse opening and closing, reduce vibration and noise of the mechanical hand during transverse opening and closing, reduce wear of parts, and improve service life and comfort.
[0035] The outer wall of the main drive ring block 23 is provided with a rope groove matched with the pull rope, and the pull rope is fixed to the outer wall of the main drive ring block 23 to prevent the pull rope from slipping during driving. The inner wall of the hollow column 24 is provided with a pull rope guide hole to guide the pull rope and fix its movement path, reducing wear of the inner wall of the hollow column 24.
[0036] The outer edge of the secondary drive ring block 26 is provided with a clamping groove matched with the pull rope, to strengthen the connection between the pull rope and the secondary drive ring block 26 and avoid slipping. The two ends of the phalange connecting frame 25 are connected to the main frame 1 through hinge pins, to make the connection between the phalange connecting frame 25 and the main frame 1 more stable and provide a reliable rotation fulcrum.
[0037] The reinforcing rib is arranged on the transverse arch block 42, the structural strength of the transverse arch block 42 is improved, the transverse arch block 42 is prevented from being deformed due to transverse stress, the transverse arch block 42 and the main frame 1 are hingedly connected through a pin shaft, a reliable rotating connection point is provided, the transverse arch block 42 can be flexibly opened and closed, and the top of the main frame 1 is provided with three through holes for connecting external driving equipment.
[0038] In summary, the mechanical hand with movable metacarpal mechanism, when the electric control telescopic rod 21 is started, its output shaft drives the main drive ring block 23 to move linearly through the vertical main shaft 22, the main drive ring block 23 drives the secondary drive ring block 26 through the pull rope, and the secondary drive ring block 26 drives the phalanx connecting frame 25 fixed thereon to rotate around the hinge point of the side wall of the main frame 1 under the action of the pull force, while driving the three mechanical phalanges 3 to bend. In this way, the mechanical phalanges 3 installed on the phalanx connecting frame 25 can no longer be limited to bending movement, but can rotate as a whole in the longitudinal arch direction, thereby realizing the effect of the activity of the human metacarpal bones in the longitudinal arch direction. At this time, the mechanical phalanges 3 on the metacarpal mechanism 2 become the longitudinal reference point. At the same time, when the bidirectional telescopic push rod 41 is actuated, one end thereof is hinged to one side of the lateral arch block 42, and the output shaft at the other end is hinged to the other side of the lateral arch block 42, and with the extension and retraction of the bidirectional telescopic push rod 41, the two lateral arch blocks 42 make symmetrical opening and closing movements around the respective hinge points with the bottom of the main frame 1. The two lateral arch blocks 42 drive the two phalanx connecting frames 25 hinged thereto, so that the two mechanical phalanges 3 installed on the two phalanx connecting frames 25 open and close laterally. In this way, the mechanical phalanges 3 can adjust the opening and closing size under the driving action of the metacarpal mechanism 2, and can adjust the opening and closing size of two of the mechanical phalanges 3 under the lateral movement action of the wrist lateral arch mechanism 4. When the three mechanical phalanges 3 are in the initial parallel position, the mechanical hand as a whole maintains an open posture; when the electric control telescopic rod 21 drives the main drive ring block 23 to drive the secondary drive ring block 26 and the phalanx connecting frame 25 thereon to rotate, a specific included angle is formed between the mechanical phalanges 3 on the metacarpal mechanism 2 and the other two mechanical phalanges 3 driven by the wrist lateral arch mechanism 4, the three-fingered dexterous hand can adjust the spatial envelope posture according to the shape of the target object, and stable grasping is realized; when the bidirectional telescopic push rod 41 further drives the lateral arch blocks 42 to open and close, the two laterally distributed mechanical phalanges 3 open and close in the wrist lateral arch direction, thereby changing the included angle between the longitudinal reference mechanical phalanges 3, and realizing the adaptive envelope of objects of different sizes. Since the hinge points of each phalanx connecting frame 25 are provided with a volute spring, the mechanical hand can automatically return to the horizontal parallel state when there is no external force or the motor is not driven, thereby ensuring the initial stability. Therefore, through the longitudinal rotation provided by the metacarpal mechanism 2 and the lateral rotation provided by the wrist lateral arch mechanism 4, the three-fingered dexterous hand has a composite movement capability in the longitudinal arch and lateral arch directions, not only increases the diversity of the spatial envelope and the range of the working space, but also can break through the limitation of the metacarpal fixed structure in the parallel extension gripping posture, and realize stable gripping of different size flat target objects, thereby greatly improving the flexibility and adaptability of grasping.In summary, by using the electrically controlled telescopic rod 21 to drive the vertical main shaft 22, which in turn drives the main drive ring block 23 to pull the auxiliary drive ring block 26 and the finger bone connecting frame 25 to rotate, and combined with the bidirectional telescopic push rod 41 to drive the horizontal bow block 42 to achieve lateral opening and closing, the mechanical finger bone 3 can simultaneously obtain a composite motion effect of longitudinal and lateral movements. This allows the three-finger dexterous hand to automatically adjust its spatial envelope posture according to the shape and size of the target object during the grasping process. It can stably clamp irregular workpieces and reliably grasp flat workpieces in a parallel extended state, thereby improving the overall flexibility, adaptability and stability of the robot, ensuring the coordinated cooperation of various mechanisms on the main frame 1, and realizing efficient grasping and operation of different target objects.
[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
Claims
1. A robotic hand with a movable metacarpal mechanism, characterized in that: include: The main frame (1) is used to provide a supporting framework; Metacarpal mechanism (2), said metacarpal mechanism (2) is mounted on the main frame (1); Mechanical phalanges (3), said mechanical phalanges (3) are mounted on the metacarpal mechanism (2); A transverse wrist arch mechanism (4) is provided on the main frame (1). Three mechanical phalanges (3) are provided. One of the mechanical phalanges (3) is connected to the metacarpal mechanism (2), and the other two mechanical phalanges (3) are connected to the transverse wrist arch mechanism (4). The transverse wrist arch mechanism (4) is used to open and close the two mechanical phalanges (3) laterally. The mechanical phalanges (3) are used to grasp the workpiece. The metacarpal mechanism (2) includes an electrically controlled telescopic rod (21), which is fixedly connected to the inner wall of the main frame (1). The output shaft of the electrically controlled telescopic rod (21) is connected to a vertical main shaft (22). A main drive ring block (23) is fixedly connected to the bottom of the vertical main shaft (22). A hollow column (24) is fixedly connected to the bottom of the main frame (1). A finger bone connecting frame (25) is hinged to the side wall of the main frame (1). A secondary drive ring block (26) is fixedly connected to the side of the finger bone connecting frame (25) near the hollow column (24). A pull rope is connected between the secondary drive ring block (26) and the main drive ring block (23). The pull rope passes through the inner wall of the hollow column (24). There are three sets of pull ropes and secondary drive ring blocks (26). The wrist transverse bow mechanism (4) includes a bidirectional telescopic push rod (41) and a transverse bow block (42). There are two transverse bow blocks (42), which are symmetrically hinged to the bottom of the main frame (1). One side of the transverse bow block (42) is hinged to the bidirectional telescopic push rod (41), and the other side of the transverse bow block (42) is hinged to the output shaft of the bidirectional telescopic push rod (41). There are three finger bone connecting frames (25). Both of the transverse bow blocks (42) are hinged to the finger bone connecting frames (25). The hinge points of the finger bone connecting frames (25) are provided with spiral springs to maintain the horizontal state of the finger bone connecting frames (25) without external force. The middle shell of the bidirectional telescopic push rod (41) is slidably connected to the main frame (1) to keep the two transverse bow blocks (42) in a straight line position when they move relative to each other.
2. The robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: A connecting sleeve is provided between the output shaft of the electric telescopic rod (21) and the vertical main shaft (22).
3. A robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: The inner wall of the main frame (1) is provided with a motor mounting base for stably connecting the electric telescopic rod (21).
4. A robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: The top of the main frame (1) is provided with three through holes for connecting external drive devices.
5. A robotic hand with a movable metacarpal mechanism according to claim 4, characterized in that: A spiral spring is provided at the junction of the finger bone connecting frame (25) and the main frame (1) to restore the finger bone connecting frame (25) to its initial position when there is no motor drive.
6. A robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: The outer wall of the main drive ring block (23) is provided with a rope groove that cooperates with the pull rope.
7. A robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: The inner wall of the hollow column (24) is provided with a rope guide hole.
8. A robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: The outer edge of the secondary drive ring block (26) is provided with a slot for cooperating with the pull rope, and both ends of the finger bone connecting frame (25) are connected to the main frame (1) by hinge pins.
9. A robotic hand with a movable metacarpal mechanism according to claim 1, characterized in that: The horizontal bow block (42) is hinged to the main frame (1) by a pin.