JPS6122578B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an artificial prosthetic hand used to enable a patient who has lost an arm due to an accident or the like to carry out daily life similar to that of a working adult.

[Technical background of the invention and its problems]

In order to enable many patients who have lost their arms due to illness or accidents to live a daily life similar to that of working adults, we need a lightweight, easy-to-control device that can perform movements similar to those of a human arm and that does not make patients feel uncomfortable. It is necessary to provide artificial limbs without artificial limbs.

However, an artificial hand that satisfies the above-mentioned requirements has not yet appeared, and known artificial hands have a particularly large defect in ease of control. In other words, the projection trajectory of the wrist and elbow in the horizontal plane when the wrist of the prosthetic hand captures its target using a known simulation method is as shown in Figures 1 and 2. This method is limited to complex cases involving horizontal adduction of the upper arm and bending and stretching of the forearm, and has the disadvantage of requiring patient practice or advanced control techniques using a sophisticated control system.

[Purpose of the invention]

The present invention was made in view of the above points, and consists of three points: shoulder, elbow, and wrist. △ OEW corresponds to the upper arm and the forearm.
By choosing the lengths of EW to be equal, ＜EOW=＜
Since the relationship of EWO = σ (forward elevation angle) and <WEE' = 2σ always exists, <WEE' and <EOW are linked to each other, resulting in 1/2 of the angle change given to <WEE'.
If the amount is configured to feed back <EOW in the opposite direction, focus on the fact that the W point corresponding to the wrist is always on the prescribed vector line, and connect the shoulder and the target in advance using the patient's intuition or positioning system. Set the vector, give the necessary adduction angle and upper arm elevation angle θ to the prosthetic hand, and at the same time, maintain the tension angle that does not impede the movement of the elbow while giving the forearm a flexion/extension angle to move the wrist above the vector. The purpose of the present invention is to provide an artificial hand that can capture a target by moving the hand.

[Summary of the invention]

The present invention provides an artificial hand in which a shoulder and an upper arm, and an upper arm and a forearm are freely joined to each other via a support shaft, and in which an actuating device is provided in each of the upper arm and the forearm to move the upper arm and the forearm around the support shaft. In addition, the length of the upper arm and forearm are set to be approximately the same, and the upper arm and shoulder are set to have approximately the same length. A gear device is provided to rotate the forearm around a connecting shaft, and the gear device rotates the forearm by half of the external angular displacement of the forearm in the triangle formed by the shoulder, upper arm, and forearm. This artificial hand is characterized in that the upper arm part is rotated in a direction opposite to the direction of rotation during bending and stretching movements of the upper arm part.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 5, reference numeral 1 designates a part of a support frame for attaching and fixing an artificial prosthetic hand to a human body, and a support shaft 2 is rotatably attached to this support frame 1. The support shaft 2 serves to maintain the axis of the prosthesis vertically and to perform internal rotation and external rotation in a horizontal plane of the prosthetic hand. A worm gear 3 is integrally formed at the tip of the support shaft 2, and a fork-shaped bearing frame 3' is provided on the surface of the worm gear 3 opposite to the support shaft 2. A worm 4 is disposed to mesh with the worm gear 3. The worm 4 is attached to a rotating shaft of a small electric motor 5 fixed to the support frame 1, and the small electric motor 5 performs external rotation and internal rotation in a horizontal position.

On the other hand, an arm cover 6 having a corresponding fork-shaped support frame 6' is pivotally supported by a fork-shaped bearing rack 3' provided on the worm gear 3 via a support shaft 7. A worm gear 8 is attached to a portion of the support shaft 7 between the fork-shaped bearing racks 3'. As shown in FIG. 6, a small electric motor 9 is fixedly attached to the arm cover 6, and a worm 9' provided on the rotating shaft of the small electric motor 9 meshes with the worm gear 8. A small electric motor 9 is used to perform a forward lifting movement of the upper arm in the vertical plane. Further, an arm barrel 10 having an internal gear 10' is rotatably attached to the arm cover 6 so as to surround a small electric motor 9 via a ball bearing 10''. , a pinion 11' provided on the rotating shaft of a small electric motor 11 arranged in parallel with the small electric motor 9 is engaged with the small electric motor 9.The small electric motor 11 performs a rotational movement σ about the vector direction OW shown in FIG. 3. A bearing hole is formed in a portion of the support plate 14 of the arm tube 10 on the same line as the support shaft 7, and support shafts 14' and 14'' are mounted in this bearing hole. An arm barrel 12 is rotatably attached to the arm barrel 10.

The arm tube 12 forms a fork-shaped bearing rack 12' on its lower side, and at the same time connects a bearing hole of a support plate 13 extending upward from both sides thereof to a support plate 14 extending upward from both sides of the arm tube 10. The arm lid 6 and the arm tubes 10 and 12 cooperate to form an upper arm portion.

On the other hand, an arm tube 15 having a fork-shaped support frame 15' on the upper side is attached to the bearing frame 12' of the arm tube 12 via a shaft 16 passing through the fork-shaped support frame 15' and the bearing frame 12'. There is. A worm gear 17 mounted between the fork-shaped support frames 15' of the shaft 16 meshes with a worm 18' provided on the rotating shaft of a small electric motor 18 provided in the arm tube 12.

The bevel gear 19 provided on the shaft 16 is connected to a bevel gear 20 provided on the support shaft 14'' via a series of bevel gears.Rotation is transmitted between the two shafts at a gear ratio of 2:
1, the rotation directions are set to be opposite to each other. That is, for every rotation of the support shaft 14'', the shaft 16 rotates twice in the opposite direction.

Further, an arm barrel 21 is coaxially and rotatably attached to the arm barrel 15 via a ball bearing 22. A fork-shaped bearing rack 21' is provided below the arm tube 21.
However, an internal gear 21'' is formed on the upper surface, and the internal gear 21'' meshes with a pinion 23' provided on the rotating shaft of a small electric motor 23 fixed to the arm tube 15, thereby causing the arm tube 21 and the arm to rotate. The tube 21 constitutes a forearm.

Reference numeral 24 in FIG. 5 is a palm body whose upper side forms a fork-shaped support frame 24', and whose lower side is equipped with five fingers 25 that can be freely bent and extended by a small electric motor, and which is attached to the bearing frame 21' and the support frame 24'. It is swingably connected to the forearm by a shaft 26 passing through the frame 24'. Further, 27 is a bevel gear fixed to the shaft 26, 28 is a small electric motor fixed to the arm barrel 21, and the bevel gear 2
8' meshes with the bevel gear 27.

In the above configuration, the center of the upper joint of the upper arm, that is, the position of the support shaft 7, is a, the center of the joint of the upper arm and forearm, that is, the center of the shaft 16, is b, and the center of the palm is c.
The upper arm length ab=the forearm length bc. As a result, as shown in Fig. 3, the following relationships hold: OE=EW, <EOW=<EWO=σ (forward elevation angle), <EWW'=2σ, and <
If EWW' and <EOW are linked to each other, and 1/2 of the angular change given to <WEE' is fed back to <EOW in the opposite direction, the W point corresponding to the wrist will always be on the specified vector line. It will be positioned.

Next, the action will be explained.

The adduction and abduction of the entire horizontal position, including the upper arm, forearm, and palm body, that is, the angle Θ in the horizontal plane is
By starting the electric motor 5 provided on the support frame 1, rotating the worm 4 provided on the rotating shaft of the motor 5, and rotating the worm gear 3 that meshes with the worm 4, the support shaft 2 is rotated.
Rotate around the center. The tensioning motion of the elbow is related to the above-mentioned movement, and the internal gear 10' provided on the arm barrel 10 is
The pinion 11' that meshes with this is rotated by an electric motor 11 provided on the arm cover 6, and the arm tube 10 is rotated relative to the arm cover 6 via a ball bearing 10''. The palm, forearm, and palm body rotate internally or externally.

The bending and stretching motion of the forearm and palm body is achieved by starting the electric motor 18 provided on the arm tube 12, rotating the worm 18' provided on the motor 18, and rotating the worm gear 17 that meshes with the worm gear 17, thereby turning the shaft 16. Rotate it around the center. In response to the bending and stretching movements of the forearm and palm body, the arm tube 12 is moved to the support shaft 1 relative to the arm tube 10.
It is designed to move in opposite directions about pivots 4' and 14''.

That is, 1/2 of the angular displacement applied to the shaft 16 via the worm gear 17 is transmitted in the opposite direction to the shaft 14'' of the bevel gear 20 via the bevel gear group 19. 12 is displaced in the opposite direction with respect to the arm barrel 10 about the support shafts 14' and 14'' by 1/2 of the angular displacement of the forearm.

However, as the forearm bends and stretches, the center position (W) of the palm moves back and forth on a predetermined vector line as shown in Figure 3, so the patient's intuition or positioning The system allows you to set a vector connecting the shoulder and the target in advance, and determines the adduction angle required for the prosthetic hand (shoulder abduction when the shoulder is in a horizontal position,
At the same time, while maintaining a tension angle that does not impede the movement of the elbow, the forearm is given a flexion/extension angle to allow the wrist to move. By moving on a vector, the target can be easily captured.

If the pinion 23' that meshes with the internal gear 21'' is driven by the electric motor 23, the arm barrel 21 can be rotated left and right on the axis of movement relative to the arm barrel 15, and a twisting motion of the forearm and palm body can be obtained. , electric motor 28 and bevel gear 2
By driving the bevel gear 27 by 8', a beckoning motion of the palm body 24 can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, since there is no complicated correlation between each control command, control is easy, the control system is simplified, and at the same time, the control system is intuitively similar to that of a human arm. Since the patient can be made to perform the movements, there is an effect that the patient does not feel uncomfortable.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing the projection trajectories of the elbow and wrist relative to a horizontal plane during the operation of capturing a target of the prosthetic hand according to a known method, and FIG. 3 is a diagram illustrating the principle of the prosthetic hand according to the present invention. , FIG. 4 is a diagram showing the projection locus of the elbow and wrist with respect to the horizontal plane during the movement of the artificial hand according to the present invention to capture a target,
FIG. 5 is a front view of the artificial hand according to the present invention, and FIG. 6 is a side view of the artificial hand. 1... Support frame, 2... Support shaft, 3'... Bearing rack, 5
...Electric motor, 6... Arm cover, 6'... Support frame, 7...
Support shaft, 9... Electric motor, 10... Arm tube, 11... Electric motor, 12... Arm tube, 12'... Bearing rack, 13,
14... Support plate, 14, 14'... Support shaft, 15...
Arm tube, 15'... Support frame, 16... Shaft, 18... Electric motor, 19, 20... Bevel gear, 21... Arm tube, 2
1'... Bearing rack, 23... Electric motor, 24... Palm body, 24'... Support frame, 25... Finger, 26... Shaft,
28...Electric motor.

Claims (1)

[Claims] 1. An artificial hand in which the shoulder and the upper arm, and the upper arm and the forearm, are freely joined to each other via a support shaft, and each of the upper arm and the forearm has a built-in actuating device for movement around the support shaft, and ,
The lengths of the upper arm and forearm are set to be approximately equal, and a support shaft is attached to the upper arm that connects the upper arm and shoulder in accordance with the amount of rotation of the forearm around the support shaft. A gear device is provided for rotation around the center, and the gear device bends and stretches the forearm by one half of the external angular displacement of the forearm in the triangle formed by the shoulder, upper arm, and forearm. An artificial prosthetic hand characterized in that the upper arm rotates in a direction opposite to the direction in which it rotates.