RU2416380C2 - Prosthesis of forearm - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine. Prosthesis of forearm contains supporting sleeve with fastening elements, receiving sleeve with possibility of rotation, artificial hand, and kinematic chain for transmission of rotation from receiving sleeve to artificial hand. Into kinematic chain for transmission of rotation from receiving sleeve to artificial hand introduced is bidirectional overrunning clutch. Clutch ring is connected to the hand body. Shaft of receiving sleeve is connected to the driving fork of overrunning clutch. Cam of overrunning clutch by means of shaft, which it is mounted on, is connected to inlet shaft of the mechanical transmission of hand by jointing fork. Mechanical transmission of hand is made in form of partly rotary orthogonal transmission with flexible connections, containing two cases, where the first case is fixed motionlessly on the hand body and the second one is movably fixed in the first case with possibility of translational motion together with two guides, motionlessly fixed on it. On input shaft of transmission, hingedly installed in the second case, fixed is inlet roller of flexible transmission, on which flexible connection is fixed. Outlet shaft of transmission is hingedly installed in the first case and outlet roller with fixed on it flexible connection is fixed on it. Crankpin, hingedly connected by means of connecting rod with hand leverage, is fixed motionlessly on the outlet roller butt end. Two screws of tension device are installed in the first case with possibility of rest on the second case of transmission.

EFFECT: invention ensures increase of invalid's convenience due to elimination of the back play in mechanical transmission and providing possibility of fixation of fingers in full range of their opening, which increases precision of movements and thus reduce time of their performance.

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Description

The proposed device relates to medical equipment, namely to prosthetics and prosthetics.

Known “Muscular rotator of the forearms by AS No. 2128483, IPC A61F 2/54, 2/72, comprising a front (outer) ring and a rear (inner) ring, an insert and a washer provided with a groove (groove), the front ring having an opening with the possibility of inserting an insert ribbon through it and put on on the back ring equipped with a washer. The hole is made with the possibility of sealing it with a flexible sticky transparent tape, which ensures that the liner does not fall out during rotation.

The disadvantage of this device is the inability to control the mechanism of the brush through the rotational movement of the forearm.

Also known is the “Plastic forearm prosthesis”, see “Designs of prosthetic and orthopedic products”. - M .: Light and food industry, 1984, pp. 150-151, containing the sleeve of the forearm, the mechanism of passive rotation of the hand and the active traction brush with a spring grip and active opening of the fingers.

The disadvantage of this device is that the fingers are closed using a spring, and the fingers are controlled by pulling the traction with an axillary loop.

The closest in functional and technical essence is the forearm prosthesis chosen by the authors as a prototype. No. 1416120, IPC A61F 2/54, containing a sleeve made in the form of tires connected by a ring and provided with a cuff. The receiving sleeve is rotatable in the carrier sleeve. There is also an artificial brush with a knot for regulating the gear ratio of the gripping mechanism.

The disadvantages of the prototype include:

- a large free play (backlash) during the operation of the mechanism due to the use of a bevel gear in it;

- lack of fixation and self-inhibition of the mechanism of fingers in the entire range of their disclosure.

The objective of the invention is the creation of a simple and reliable prosthesis of the forearm, which increases the convenience of a disabled person by eliminating backlash in mechanical transmission and providing the possibility of fixing the fingers in the entire range of their disclosure, which increases the accuracy of movements and thereby reduces their execution time.

To solve this problem, a forearm prosthesis containing a supporting sleeve with fastening elements, rotatable placed in it, a receiving sleeve, an artificial brush, as well as a kinematic chain for transmitting rotation from the receiving sleeve to the artificial brush, to a kinematic chain for transmitting rotation from the receiving sleeve to a double-acting overtaking clutch is inserted into the artificial brush, the sleeve of the coupling being connected to the brush body, while the shaft of the receiving sleeve is connected to the drive fork of the overtaking clutch, and the cam of the overtaking clutch is It is connected to the drive shaft of the mechanical transmission of the brush, which is made in the form of a half-turn orthogonal transmission with flexible connections, containing two bodies, of which the first body is fixedly mounted on the brush body, and the second body is movably fixed in the first case with the possibility of translational movement together with two motionlessly fixed guides on it, while on the input shaft of the drive pivotally mounted in the second case, the input roller of the flexible transmission is fixed, on which the flexible coupling is fixed b, made, for example, in the form of a cable, and the output shaft of the transmission is pivotally mounted in the first housing and the output roller is fixed on it with a flexible transmission connection fixed to it, and at the end of the output roller the crank pin is fixedly mounted pivotally via a connecting rod with a lever mechanism brushes, while in the first case two screws of the tensioning device are installed with the possibility of abutment in the second transmission case.

The drawing shows a constructive kinematic diagram of the proposed device.

The forearm prosthesis contains a supporting sleeve 1 with a stiff flange 2, which can be made in the form of tires, a receiving sleeve 3, to which the shaft 4 is connected. A double-sided overtaking clutch 6. An overtaking clutch is included in the kinematic chain of motion transmission from the receiving sleeve 3 to the hand 5. contains a clip 7, half-disks 8, cam 9, a spring plug 10 connected to the shaft 4, and half-disks 8 are pressed against the clip 7 by springs 11. The clip 7 is placed in the housing 12, which is connected to the brush 5. Using the fixing unit 13, the cam 9 using shaft 14, on which he fixed, connected by means of a connecting fork 15 to the input shaft 16, on which the input roller 17 of a half-turn orthogonal transmission with a flexible connection is fixed, made, for example, in the form of a cable 18, fixed by a clip 19 on the roller 17. The input shaft 16 is pivotally mounted in the housing 20 which, by means of the guides 21 fixed in it movably with the possibility of translational motion, is mounted in the housing 22 fixedly mounted on the housing of the brush 5. On the housing 20 are fixed two intermediate rollers 23, through which walks flexible transmission cable. In the housing 22, the output shaft 24 of the flexible transmission is pivotally mounted with the output roller 25 fixed to it, while the transmission cable is also fixed on the output roller by means of a second clip 19. In this case, two tensioner screws 26 are installed in the housing 21, which, when rotated, abut against the housing 20. In addition, at the end of the output roller 25, a crank pin 27 is fixedly mounted pivotally using a connecting rod 28 with a lever mechanism of the brush, namely, the first finger 29 of the brush. In this case, the brush mechanism comprises a first finger 29 and a block of the second to fifth fingers 30, pivotally mounted on the brush body and pivotally connected to each other by means of a connecting rod 31. Adjusting the orthogonal part-turn gear consists in selecting the free-wheeling mechanism with a flexible connection and is performed using screws 26, allowing during their rotation to squeeze the housing 20 from the housing 22 along the guides 21, thus ensuring the selection of play by tensioning the cable 18 on the rollers 17, 23, 25.

The prosthesis works as follows.

In the initial state, the clutch 6 is jammed, the brush 5 is deployed, for example, with the palm down, the stump with the receiving sleeve 3 is set in the average physiological position, the grip is closed (fingers closed). The coupling 6 is jammed, the half-disks 8 are pressed against the clip 7 by the springs 11. When the receiving sleeve 3 is turned in the direction of supination (turning inward), the receiving sleeve rotates the shaft 4 with the driving fork 10. The driving fork 10 wedges the coupling 6 and transfers the rotation to the cam 9 with the shaft 14 and then through the connecting fork 15 to the shaft 16 with the roller 17. When turning the roller 17, the flexible gear drives the roller 25, which through the connecting rod 28 drives the lever mechanism of the brush 29, 30, 31 to open. When stopping, the clutch 6 is jammed by pressing the half-disks 8 to the clip 7 by the springs 11. The brush is closed by turning the stump in the opposite direction. The interaction of the parts of the device occurs in the same order with movement in the opposite direction.

The positive effect of the claimed invention is as follows: the convenience of a disabled person is ensured by increasing the accuracy of movements and thereby reducing the time of performing a motor operation when using a prosthesis by eliminating backlash in a mechanical transmission and making it possible to fix fingers in the entire range of their disclosure.

Claims (1)

A prosthetic arm containing a supporting sleeve with fastening elements, rotatable therein, a receiving sleeve, an artificial brush, and also a kinematic chain for transmitting rotation from the receiving sleeve to the artificial brush, characterized in that the kinematic chain for transmitting rotation from the receiving sleeve to the artificial a double-acting overtaking clutch is introduced; moreover, the sleeve of the coupling is connected to the housing of the brush, while the shaft of the receiving sleeve is connected to the drive fork of the overtaking clutch, and the cam of the overtaking clutch is the shaft on which it is mounted is connected by means of a connecting fork to the input shaft of the mechanical transmission of the brush, which is made in the form of a half-turn orthogonal transmission with flexible connections, containing two cases, of which the first case is fixedly mounted on the brush case, and the second case is movably fixed in the first the housing with the possibility of translational movement together with two guides fixed on it, while on the input transmission shaft, pivotally mounted in the second housing, the input is fixed a flexible transfer roller, on which a flexible connection is fixed, and the output transmission shaft is pivotally mounted in the first housing, and an output roller is fixed on it with a flexible transmission connection fixed to it, and at the end of the output roller the crank pin is fixedly mounted pivotally by means of a connecting rod with with the lever mechanism of the brush, while in the first case two screws of the tensioning device are installed with the possibility of abutment in the second transmission case.