Patent ID: 11873856
Assignee: BPC LG 2, LLC
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 17:
18. A torque control fastener system, comprising:
a fastener nut having a nut proximal end and a nut distal end, a nut bore extending from the nut proximal end into the fastener nut and defining a nut bore axis, a plurality of nut bore threads on at least a portion of the nut bore, and formed of a nut material having a nut Rockwell C hardness of no greater than 40 RWC and a nut coefficient of thermal expansion;
a helical wire insert formed to create a plurality of insert coils forming insert external threads and a plurality of insert internal threads, and formed of an insert material having an insert Rockwell C hardness of at least 43 RWC and an insert coefficient of thermal expansion greater than the nut coefficient of thermal expansion, wherein a portion of the insert external threads mate with a portion of the nut bore threads in a portion of the nut bore and engage the fastener nut, wherein majority of the plurality of insert coils are regular coils having a circular end profile, and at least one of the plurality of insert coils is a locking coil having a non-circular end profile including at least three straight segments, and the locking coil is located between regular coils, and wherein the helical wire insert has an insert distal end and an insert proximal end, a first quantity of regular coils are located between the insert distal end and the locking coil, a second quantity of regular coils are located between the insert proximal end and the locking coil, and the first quantity is different than the second quantity;
a shaft having a plurality of shaft threads that mate with a portion of the insert internal threads such that an insertion torque is required to create relative movement between the shaft threads and the insert internal threads in a first direction, and a removal torque is required to create relative movement between the shaft threads and the insert internal threads in a second direction opposite the first direction;
wherein a hardness differential between the insert Rockwell C hardness and the nut Rockwell C hardness is 2-10, and the insert coefficient of thermal expansion is at least 1.5×10−6/° C. greater than the nut coefficient of thermal expansion.