Anti-rotation mechanism for telescopic screw assembly
First Claim
1. A injection assembly comprising:
- a housing;
a barrel positioned in the housing, the barrel including a proximal end, a distal end, an axis extending between the proximal and distal ends, and a chamber for storing medicine;
an elongate anti-rotation shaft rotationally fixed to the housing, the shaft having a non circular cross section;
an inner screw having an inner screw opening configured to complementarily receive the anti-rotation shaft to prevent rotation of the inner screw with respect to the anti-rotation shaft but allow respective linear translation along the axis;
a outer screw rotatable with respect to the housing and having an outer screw opening to threadably receive the inner screw, wherein rotation of the outer screw translates the inner screw along the axis and along the anti-rotation shaft; and
a plunger coupled to a distal end of the inner screw and moveable with respect to the chamber to push the medicine out of the chamber when the outer screw is rotated.
3 Assignments
0 Petitions
Accused Products
Abstract
An injection assembly includes a housing with a barrel positioned within the housing. The barrel includes an axis extending from a proximal end to a distal end thereof and a chamber for storing medicine. An elongate anti-rotation shaft is rotationally fixed to the housing and has a non-circular cross-section. The injection assembly includes an inner screw having an inner screw opening to complementarily receive the anti-rotation shaft to prevent rotation of the inner screw with respect to the anti-rotation shaft but allow respective linear translation along the axis. An outer screw is positioned within, and rotatable with respect to, the housing and has an outer screw opening to threadably receive the inner screw, wherein rotation of the outer screw translates the inner screw along the axis and along the anti-rotation shaft. A plunger is coupled to the distal end of the inner screw and is moveable with respect to the chamber to push the medicine out of the chamber when the outer screw is rotated.
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Citations
17 Claims
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1. A injection assembly comprising:
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a housing; a barrel positioned in the housing, the barrel including a proximal end, a distal end, an axis extending between the proximal and distal ends, and a chamber for storing medicine; an elongate anti-rotation shaft rotationally fixed to the housing, the shaft having a non circular cross section; an inner screw having an inner screw opening configured to complementarily receive the anti-rotation shaft to prevent rotation of the inner screw with respect to the anti-rotation shaft but allow respective linear translation along the axis; a outer screw rotatable with respect to the housing and having an outer screw opening to threadably receive the inner screw, wherein rotation of the outer screw translates the inner screw along the axis and along the anti-rotation shaft; and a plunger coupled to a distal end of the inner screw and moveable with respect to the chamber to push the medicine out of the chamber when the outer screw is rotated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A injection assembly comprising:
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a housing; a barrel positioned in the housing including a proximal end, a distal end, an axis extending between the proximal and distal ends, and a chamber for storing medicine; an elongate anti-rotation shaft rotationally fixed to the housing, the anti-rotation shaft having a non-circular cross section; an inner screw having an inner screw opening configured to complementarily receive the anti-rotation shaft to prevent rotation of the inner screw with respect to the anti-rotation shaft but allow respective linear translation along the axis, the inner screw including an inner screw external thread; an intermediary screw including an intermediary screw external thread and an intermediary screw opening with an intermediary screw internal thread threadably engageable with the inner screw external thread such that rotation of the intermediary screw moves the inner screw along the axis and along the anti-rotation shaft; an outer screw rotatable with respect to the housing and having an outer screw opening to receive the intermediary screw and including an outer screw internal thread engageable with the intermediary screw external thread such that rotation of the outer screw moves the intermediary screw along the axis and rotates the intermediary screw; and a plunger coupled to a distal end of the inner screw and moveable with respect to the chamber to push the medicine out of the chamber when the outer screw is rotated. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification