James A Kwieraga

US Patent:

40971805, Jun 27, 1978

Filed:

Feb 10, 1977

Appl. No.:

5/759955

Inventors:

James A. Kwieraga - Durham CT

Assignee:

TRW Inc. - Cleveland OH

International Classification:

B23G 516

US Classification:

408154

Abstract:

The specification and drawings disclose a collapsible tap of the type including an elongated, cylindrical body or housing having an axially extending actuating plunger mounted for selective movement longitudinally of the body. The outer end of the plunger has a generally conical portion which functions to provide camming surfaces. Suitable chaser cutting elements are mounted for radial movement in the body. Each element includes a surface in engagement with a corresponding camming surface of the plunger such that axial movement of the plunger produces radial movement of the elements. The elements are maintained in engagement with the camming surfaces by clip members which extend radially from the conical portion of the plunger with resilient, laterally directed terminal portions that engage grooves formed in the sides of the elements. The terminal portions are related to the grooves in a manner to produce a continuous bias acting to maintain the elements in contact with the camming surfaces while permitting relative axial movement between the elements and the camming surfaces.