The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 21, 1989
Filed:
Jun. 27, 1988
Douglas C Armstrong, Novi, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A self contained servo mechanism (10, 110) for actuating a friction band assembly (13) in a planetary gear set. The servo mechanism (10, 110) is contained within a housing (25, 125) which incorporates a piston chamber (32, 132). The housing (25, 125) is demountably secured within a socket cavity (21, 121) provided in the transmission case (11, 111). A piston means (40, 140) is slidably received within the chamber (32, 132), and the piston means (40, 140) is operatively secured to an actuating pin (55, 155) that is slidably received within a pilot bore (34, 134) which penetrates the housing (25, 125) and which is aligned with the piston chamber (32, 132). The actuating pin is, in turn, operatively connected to a friction band assembly (13) within the transmission case (11, 111). A cover (41, 141) is secured to the transmission case (11, 111) not only to close the socket cavity (21, 121) and the interior cavity (12, 112) of the transmission case (11, 111) from the environment but also to close the piston chamber (32, 132) and to define a pressure portion (51, 151) of the chamber (32, 132) to act against the head (52, 152) of the piston (40, 140). Feed means (75, 175) are provided to effect hydraulic communication to the pressure portion (51, 151) of the piston chamber (32, 132).