The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 13, 1979
Filed:
Jul. 20, 1977
Martin Richter, Freising, DE;
Albert Busler, Puchheim, DE;
Hilti Aktiengesellschaft, Schaan, LI;
Abstract
A safety disk assembly is used in determining when a predetermined force is exerted in tightening a nut, bolt or similar fastening member to a base structure. The safety disk assembly is positioned between a fastening part, such as a nut, and the surface of the base structure. The safety disk assembly includes a first disk and a second disk with a shear pin interconnecting them. Additional shear elements can be used in the assembly. Preferably, a thin layer of Teflon is positioned between the disks. When a torque is applied to the fastening member, the shear pin breaks when a predetermined break point is reached. The friction coefficients of the disk surfaces and the effective radii of the disks are selected to provide the predetermined break point characteristics. When the shear pin breaks one of the disks can move relative to the other. An indicator is incorporated into the safety disk assembly to show when the predetermined break point has been exceeded.