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:
Oct. 19, 1993
Filed:
Dec. 31, 1992
William H Kohler, Ringwood, NJ (US);
Tec Tran Corporation, Mahwah, NJ (US);
Abstract
A railway brake actuator which provides both service and parking braking comprises a cylinder having an operating cavity. A piston assembly in the operating cavity has a stepped bore forming second and third cavities and is extended by hydraulic pressure and retracted by a spring to apply and release the service brake. Hydraulic pressure extends a hollow parking brake piston from the second cavity to extend the piston assembly and apply the parking brake. A one-way clutch comprising ramps and rollers locks the piston in parking brake applied position. Hydraulic pressure disables the clutch to enable spring retraction of the parking brake piston and the piston assembly to release the parking brake. A gripper ring on the piston assembly operates between cylinder abutments to limit piston assembly retraction to provide slack, and enables slippage on the piston assembly on extension to adjust for brake wear. In another embodiment, a brake actuator has a cylinder housing an inner piston that is extended by springs and is retracted hydraulically. The cylinder houses an outer piston, which is connected to the inner piston through a similar ramp/roller one-way clutch, and mounts a gripper ring. The inner piston extends the outer piston relative to the gripper ring to apply the brake. Another spring retracts the outer piston a distance limited by the gripper ring to provide slack. The clutch disengages the inner piston from the outer piston during retraction to compensate for brake wear.