CPC A61B 17/7014 (2013.01) [A61B 17/7004 (2013.01); A61B 17/7016 (2013.01); A61B 17/7017 (2013.01); A61B 2017/00407 (2013.01); A61B 2017/00991 (2013.01); A61B 17/66 (2013.01)] | 15 Claims |
1. An implantable growing rod assembly comprising:
a housing;
an expansion tube having an internal threading and rotatably mounted inside of the housing;
a fixed rod extending along a longitudinal axis away from the housing;
an expansion rod having an externally threaded proximal portion in mesh with the internal threading of the expansion tube such that the expansion rod is extendible from the expansion tube along the longitudinal axis; and
a bevel gear assembly disposed in the housing and adapted to translate the expansion rod along the longitudinal axis, wherein the bevel gear assembly includes a bevel pinion gear and a bevel output gear perpendicular to the bevel pinion gear, the bevel output gear being attached to a proximal portion of and rotatably coupled with the expansion tube;
a wave washer disposed between the housing and one of the first pinion bushing or the second pinion bushing and configured to exert a locking force on the bevel pinion gear to prevent undesired back drive of the bevel pinion gear;
wherein the bevel pinion gear includes a first plurality of teeth at a first end and a second plurality of teeth at a second end, wherein the first plurality of teeth engages teeth of the bevel output gear to extend the expansion rod, and wherein the locking force exerted by the wave washer is configured to push the second plurality of teeth into engagement with the teeth of the bevel output gear to lock movement of the bevel output gear and the expansion tube.
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