David E Brann

US Patent:

46430792, Feb 17, 1987

Filed:

Mar 28, 1985

Appl. No.:

6/716873

Inventors:

David E. Brann - Lemont IL
James E. Lindsay - Warrenville IL

Assignee:

General Motors Corporation - Detroit MI

International Classification:

C21D 500

US Classification:

92222

Abstract:

A cast iron piston characterized by a pearlitic matrix microstructure comprises a ring groove defined by opposed faces that are selectively hardened adjacent the piston side wall. The hardened surfaces are characterized by a martensitic matrix microstructure having a Knoop hardness of preferably at least 690. In a preferred embodiment, the groove faces are hardened by a stripe hardening process.

US Patent:

45024227, Mar 5, 1985

Filed:

Dec 27, 1982

Appl. No.:

6/453748

Inventors:

David E. Brann - Lemont IL

Assignee:

General Motors Corporation - Detroit MI

International Classification:

F01P 306

US Classification:

123 4135

Abstract:

An oil cooled piston particularly for two cycle direct injection diesel engines offers improved cooling through increasing of the combustion bowl rim radius and modifications to the understructure to provide alternate perforate gussets permitting an increased number of rim cooling ribs. An angular break from the rim radius to the squish land offsets efficiency impairment from the larger rim radius.