Implant connector
First Claim
1. An implant assembly for use in a medical implant, including an implant provided with an abutment for attachment to a prosthesis by a threaded fastener, said abutment and said implant having a cooperative male and female thread and a thrust connection between connected parts, wherein the improvement comprises a thread profile for reducing stress on selected highly stressed threads of said abutment and implant by varying the incremental lead between the male and female thread.
1 Assignment
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Accused Products
Abstract
A threaded connection for use in medical implant surgery which utilizes a read profile which includes a load flank, a stab flank, a root intermediate the stab flank and load flank, and a crest intermediate the load flank and stab flank. The distance, measured paraxially, which the screw moves one complete revolution of the connection, is the lead of the thread. In the invention, the lead varies for either the male or female member of the connector such that the load flank, effectively, is moved away from axial interference with the cooperative member as the thread is "made up" or engaged. Accordingly, the load flank interface along the length of the connection is stressed, rather than having the load flank interface stressed predominately at the end turns of the thread, as often occurs under loading of the thread. In this manner, the stress loading of the thread is spread over the multiple turns of the thread, and pre-load is not lost by the yielding of the end turn.
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Citations
16 Claims
- 1. An implant assembly for use in a medical implant, including an implant provided with an abutment for attachment to a prosthesis by a threaded fastener, said abutment and said implant having a cooperative male and female thread and a thrust connection between connected parts, wherein the improvement comprises a thread profile for reducing stress on selected highly stressed threads of said abutment and implant by varying the incremental lead between the male and female thread.
- 12. An implant assembly for use in a medical implant, including an implant provided with an abutment for attachment to a prosthesis by a threaded fastener, wherein said abutment, said implant, and said fastener each have a cooperative male and female thread and a thrust connection therebetween, wherein the improvement comprises a thread profile for reducing stress on selected threads of said male and female thread by varying the lead of one of the mating threads.
- 14. An implant assembly in a medical implant, including an implant provided with an abutment for attachment to a prosthesis by a threaded fastener, wherein said abutment, said implant, and said fastener each have a cooperative male and female thread and a thrust connection therebetween, wherein the improvement comprises a thread profile varying the lead of one of the cooperative threads, said male thread of said fastener and said female thread of said abutment having cooperative thread profiles such that the pre-load tension stress is distributed along the length of said fastener engaged with said abutment.
Specification