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:
Jan. 05, 1993
Filed:
Aug. 01, 1991
William H Kohler, Ringwood, NJ (US);
Tec Tran Corporation, Mahwah, NJ (US);
Abstract
A brake actuator for a railway brake which provides both service and parking braking comprises a cylinder having an operating cavity. A piston assembly extends into the operating cavity and has a stepped bore including second and smaller third cavities. A first hydraulic supply admits pressurized hydraulic fluid into the operating cavity to extend the piston assembly to apply the service brake. A spring applies a retracting force on the piston smaller than the hydraulic force. A hollow parking brake piston carried in the second cavity extends to react against the cylinder and extend the piston assembly in response to the supply of pressurized fluid to the second cavity from a second hydraulic supply to apply the parking brake. A mechanical lock, comprising a one-way clutch utilizing ramps and rollers, locks the piston extended from the piston assembly cylinder to maintain the parking brake applied upon removal of the second hydraulic supply force. An unlocking member is responsive to the supply of pressurized fluid to the third cavity from a third hydraulic supply to disable the clutch and enable the spring to retract the parking brake piston and the piston assembly to release the parking brake. A gripper ring grips the exterior of the piston assembly with a friction force which enables slippage on the piston assembly upon engagement with a cylinder abutment upon extension to provide adjustment for brake wear. Ring engagement with another cylinder abutment limits piston assembly retraction to provide slack.