Patent · US Expired

Thread form for soft material

US4576534A · kind A · utility

40Cited by
8References
13Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 4, 1983
Grant dateMar 18, 1986
Priority date
Expiry dateAug 4, 2003

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16B25/0068
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A screw for soft material having an assymetrical thread form which includes an upper flank comprised of a plurality of continuous helical surfaces. The upper flank surfaces are configured such that a helical protrusion is formed on the upper flank which causes increased friction between the screw and the workpiece only after seating of the screw head has occurred.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.