04084478 is referenced by 91 patents and cites 12 patents.

A screw head is provided with projections on selected of the driver-engageable surfaces of the head to interlock with surfaces and edges of the driver to reduce the tendency for the driver to slip out of engagement with the screw during driving and also to provide a temporary stick-fit between the driver and the screw.

Title
Screw heads
Application Number
5/505324
Publication Number
4084478
Application Date
September 12, 1974
Publication Date
April 18, 1978
Inventor
Frederick A Simmons
Framingham
MA, US
Agent
Wolf Greenfield & Sacks
Assignee
Phillips Screw Company
MA, US
IPC
F16B 23/00
View Original Source