Self-torquing fasteners
First Claim
Patent Images
1. A self-torquing bolt assembly comprising an inner bolt disposed at least in part in an outer threaded collar, wherein both the inner bolt and the threaded collar comprise a shape memory alloy;
- said inner bolt further including a threadless stem and an axial retainer, and said threaded collar further including a channel for receiving a portion of the inner bolt, an annular space, and a collar bottom;
wherein said inner bolt is disposed at least in part within said annular space and is secured to said threaded collar in part by said axial retainer abutting against said collar bottom, and wherein when the bolt assembly is heated, the bolt assembly is adapted to apply compressive stress to an object to torque the object to a desired compressive force value.
1 Assignment
0 Petitions
Accused Products
Abstract
A bolt made from shape memory alloy that exists in a first state and is capable of changing to a second state when heated and remains in that second state even when cooled is used to self torque itself and clamp a first fixture to a second fixture. Preferred methods for using the self-torquing bolt are disclosed.
70 Citations
22 Claims
-
1. A self-torquing bolt assembly comprising an inner bolt disposed at least in part in an outer threaded collar, wherein both the inner bolt and the threaded collar comprise a shape memory alloy;
- said inner bolt further including a threadless stem and an axial retainer, and said threaded collar further including a channel for receiving a portion of the inner bolt, an annular space, and a collar bottom;
wherein said inner bolt is disposed at least in part within said annular space and is secured to said threaded collar in part by said axial retainer abutting against said collar bottom, and wherein when the bolt assembly is heated, the bolt assembly is adapted to apply compressive stress to an object to torque the object to a desired compressive force value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- said inner bolt further including a threadless stem and an axial retainer, and said threaded collar further including a channel for receiving a portion of the inner bolt, an annular space, and a collar bottom;
- 13. A self-torquing fastener assembly made from a shape memory alloy, said fastener assembly comprising an inner fastener portion comprising an inner fastener head portion, the inner fastener portion attached to an outer fastener portion, both the inner fastener portion and the outer fastener portion are configured to change from a first phase to a second phase when activated by a heat source and remain in the second phase even after the heat source is removed, wherein the inner fastener portion is in an abutting relationship with a flat portion of the outer fastener portion at an end opposite the inner fastener head portion in both the first phase and the second phase, and wherein when the fastener assembly is fastened to an object and heated, the fastener assembly is adapted to apply a compressive force value to the object.
Specification