An object of the present invention is to provide a gear element With Which a fully functional prosthesis or prosthetic gripping device can be con?gured at loWer cost and With loWer Weight. One embodiment of the present invention is a clutch mod ule for prostheses such as prosthetic grippers, arm prostheses or hand prostheses that comprising a chassis to Which at least one ?nger prosthesis is articulated, the clutch module having a drive element, a driven element and a clutch device, Which shifts betWeen tWo gear stages depending on the torques applied to the driven element. In this Way, an adaptation to the required adjusting or gripping force occurs automatically based on the applied torque. First, a quick adjusting or grip ping or opening movement occurs, and if there is an increase in the adjusting or gripping resistance an increased adjusting or gripping force occurs along With a decreased adjusting or gripping speed. When used in a hand prosthesis, the clutch module can also be used for to open the hand. In such a case, a loW opening speed With a loW rotational speed provides high releasing forces or opening forces. Once the grip has been loosened or the prosthetic ?ngers have pried an object apart, the adjusting speed increases as the opposing force subsides,
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2 so that the gripping elements open more quickly. The shifting is therefore dependent on the torque and independent of the direction of rotation. In another embodiment the clutch device is in contact With clamping bodies, in particular clamping rollers, Which couple the drive element to the driven element in a torque-controlled manner. The clamping bodies make it possible for the clutch module to have a loW-Wearing and reliable construction and alloW the force transmission elements to be coupled to one another independently of the direction of rotation. The inde pendence from the direction of rotation can be accomplished by a symmetrical construction of the force transmission com ponents. In a further embodiment, the clutch device may have tWo sWitching elements, Which are mounted such that they are pre-stres sed and can turn in relation to each other. The sWitch ing elements have sWitching Webs or sWitching pins, Which can be brought into contact With the clamping bodies in a torque-controlled manner. The turning angle of the sWitching elements in relation to each other may be used to bring clamp ing bodies, that are respectively to be activated, into contact With the force transmission units, and the clamping bodies make it possible to drive the driven element. In this case, the sWitching elements may be kept under pre-stress by springs so that the tripping torque or response torque of the clutch module can be set for a loW opposing force. The greater the pre-stress of the springs, the greater the opposing force must be to turn the sWitching elements in relation to each other. This has the effect of increasing the tripping torque, Which can be adapted to the individual needs of the Wearer of the prosthesis or the user of the prosthetic gripping device. In one embodiment, the springs are exchangeable. Optionally, a dif ferent spring rate may be set depending on the adjusting movement, for example, a different spring rate for the open ing movement and for the closing movement of a hand pros thesis or prosthetic gripping device, so that different sWitch ing times or torques can be set for different opposing forces. The drive element may be coupled to a gear mechanism, for example a planetary gear mechanism, to be able to realiZe a speed reduction. In this case, the corresponding speed-reduc ing gear mechanism has a contact ring, With Which the clamp ing bodies for the transmission of a high torque are in contact. The clamping bodies or rollers may be arranged on a com mon driver disk, to minimiZe installation space. The driver disk has a frame in Which clamping bodies are arranged to provide for a high increase in speed. Clamping bodies, Which provide for the transmission of a high torque With a loW increase in speed, are arranged outside the frame and are in contact With a contact ring of the speed-reducing gear mecha nism. By using clamping bodies both for the increase in speed With high torque and loW rotational speed and for the increase in speed With loW torque and high rotational speed, a sliding transition betWeen the individual gear stages can be realiZed Without a noticeable sWitching operation Within the hand prosthesis. In one embodiment, gearWheels, a sWitching disk and a second sWitching element are mounted on the driver disk. The gearWheels engage and turn a sWitching ring in relation to the sWitching disk. This turn is used angle-dependently to per form sequence control of the engagement or disengagement of the clamping bodies or rollers in relation to the respective force transmission components.
BRIEF