Prosthesis coupling, a socket coupling, a rotary connector core and a compliant mounting element
A rotatable and removable wrist connection for a prosthetic hand. A prosthesis coupling includes first and second ball race sections that may be moved together or apart to constrain ball bearings to an inner zone or an outer zone to allow the prosthesis coupling to be secured to or removed from a socket coupling. A socket coupling includes a socket body for receiving a wrist coupling having a rotary connector core extending from the socket body and compliantly mounted to the socket body.
1 . A prosthesis coupling configured to rotatably and releasably engage with a race of a socket coupling, the prosthesis coupling comprising:
a. a first sleeve including a first annular ball race section;
b. a second sleeve having a second annular ball race section; and
c. bearings provided within a race formed by the first ball race section and the second ball race section;
wherein the first and second sleeves may be relatively moved such that:
i. in a first configuration, in which the first ball race section and the second ball race section are brought together, the bearings are constrained to an outer annular zone, preventing removal of the prosthesis coupling when engaged with a socket coupling; and
ii. in a second configuration, in which the first ball race section and the second ball race section are moved apart, the bearings may move to an inner annular zone, allowing removal of the prosthesis coupling from a prosthesis socket.
2 . A prosthesis coupling as claimed in claim 1 wherein the first and second sleeves are relatively rotatable and have ramp sections configured such that upon relative rotation of the inner and outer sleeves the spacing between the first ball race section and the second ball race section may be varied.
3 . A prosthesis coupling as claimed in claim 1 wherein a locking mechanism prevents relative movement between the first and second sleeves unless actuated.
4 . A prosthesis coupling as claimed in claim 3 wherein the locking mechanism engages with locking features provided on the sleeves in its locking position to prevent relative rotation with respect to the other sleeve.
5 . A prosthesis coupling as claimed in claim 4 wherein the locking mechanism moves axially between the locking position and an unlocked position.
6 . A prosthesis coupling as claimed in claim 4 wherein the locking mechanism moves transversely to the axis of the coupling between the locking position and an unlocked position.
7 . A prosthesis coupling as claimed in claim 4 wherein the locking mechanism rotates relative to the socket coupling between locked and an unlocked positions.
8 . A prosthesis coupling as claimed in claim 4 wherein the locking mechanism is in the form of a locking ring having a plurality of axial projections which engage with a plurality of locking features provided on the sleeves.
9 . A prosthesis coupling as claimed in claim 8 wherein the locking ring is moved axially between locked and unlocked positions by the movement of opposing first and second ramps and a linkage between the locking ring and the second ramp.
10 . A prosthesis coupling as claimed in claim 9 wherein a button is linked to the first ramp and configured so that movement of the button effects relative movement between the first and second ramps.
11 . A prosthesis coupling as claimed in claim 10 wherein a plurality of buttons are connected to respective ramps.
12 . A prosthesis coupling as claimed in claim 3 wherein the locking mechanism engages features of both the first and second sleeves to prevent relative rotation between the sleeves.
13 . A prosthesis coupling as claimed in claim 12 wherein the locking mechanism is a pin movable relative to the sleeves between a first position in which the pin engages features of the first and second sleeves to prevent rotation and a second position in which relative rotation of the sleeves is allowed.
14 . A prosthesis coupling as claimed in claim 13 wherein the features are apertures in the sleeves.
15 . A prosthesis coupling as claimed in claim 1 wherein an actuating mechanism moves the first and second sleeves relatively in the axial direction between the first and second configurations.
16 . A prosthesis coupling as claimed in claim 15 where the actuating mechanism is in the form of a lever and cam arrangement.
17 . A prosthesis coupling as claimed in claim 1 wherein the bearings are ball bearings.
18 . A prosthesis coupling as claimed in claim 1 wherein the first and second sleeves are biased towards the second configuration.
19 . A prosthesis coupling as claimed in claim 18 wherein a spring biases the first and second sleeves towards the second configuration.
20 . A prosthesis coupling as claimed in claim 19 wherein a torsion spring biases the first and second sleeves towards the second configuration.
21 . A prosthesis coupling as claimed in claim 20 wherein a helical torsion spring biases the first and second sleeves towards the second configuration.
22 . A prosthesis coupling as claimed in claim 21 wherein the helical torsion spring is provided within the first sleeve and includes a leg passing through a slot in the first sleeve to engage with the second sleeve.
23 . A prosthesis coupling as claimed in claim 1 further comprising a bearing cage, wherein the bearings are retained within a region defined by the first and second ball race sections and the bearing cage.
24 . A prosthesis coupling configured to rotatably and releasably engage with a race of a socket coupling, the prosthesis coupling comprising:
a. a body having an annular section;
b. a first annular ball race section provided on the annular section;
c. a second annular ball race section movable between first and second positions on the annular section;
d. bearings provided within a race formed by the first ball race section and the second ball race section; and
e. a release actuator movable in a first direction with respect to the body to move the second annular ball race section between:
i. a first configuration in which the first ball race section and the second ball race section are brought together such that the bearings are constrained to an outer annular zone, preventing removal of the connector when engaged with a socket coupling; and
ii. a second configuration in which the first ball race section and the second ball race section are moved apart such that the bearings may move to an inner annular zone, allowing removal of the prosthesis coupling from a socket coupling;
wherein the release actuator is hand operated.
25 . A prosthesis coupling as claimed in claim 24 further comprising a bearing cage, wherein the bearings are retained within the race of the prosthesis coupling by the bearing cage.