Accession Number : ADD014697

Title :   Graduated-Load Spring Washer System for Screws and Threaded Fasteners.

Descriptive Note : Patent, Filed 17 Aug 88, patented 25 Sep 90,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Rose, James D ; Suder, William H , III

Report Date : 25 Sep 1990

Pagination or Media Count : 7

Abstract : A graduated-load spring washer system for screws and threaded fasteners uses a deflection coils spring of slightly less than one coil with special end configurations for anti-marring. A cross-section of the coil spring is substantially trapezoidal, with the outer periphery thickness being the dimension of the trapezoid base and target than the inner thickness dimension. When placed under the head of a threaded fastener and flattened upon tightening of the fastener, the device maintains a large tailored preload to prevent loosening even during and after stress relaxation and creep, and eliminates the need for a usual flat washer below the coil to prevent marring. The device also eliminates requirements for use of torque application measuring tools because perload can be determined by sight or tactile sensing. Patents. (JHD)

Descriptors :   *FASTENINGS, *PATENTS, *WASHERS(SPACERS), COILS, CONFIGURATIONS, CREEP, DEFLECTION COILS, DETECTION, INTERNAL, MEASUREMENT, SCREW THREADS, SCREWS, SIZES(DIMENSIONS), SPRINGS, STRESS RELAXATION, THICKNESS, TOOLS, TORQUE, TOUCH

Subject Categories : Couplers, Fasteners, and Joints

Distribution Statement : APPROVED FOR PUBLIC RELEASE