Parking brake control system for railway vehicles
AssigneeWestinghouse Air Brake Company
InventorClemmons, Quenten T.
Life of this patent
Estimating the term…
Abstract
A parking brake for use primarily on railway vehicles of the mass transit type in conjunction with the service brake apparatus but operable independently thereof. A parking brake hydraulic cylinder is mechanically connected to the brake shoe hanger of the brake unit. After the vehicle has been brought to a stop, a parking brake application may be made by supplying pressure, by a handpump, to the hydraulic cylinder which also includes a lock-nut actuable by the pressure, in excess of a certain pressure for locking the parking brake hydraulic cylinder in its applied position. A relief valve is provided for relieving the hydraulic cylinder of hydraulic pressure when the application is to be released.
Claims7
Parking brake apparatus for use in conjunction with a tread brake unit of a railway vehicle including a brake shoe pivotally suspended on a brake shoe hanger through which braking forces are applied to the brake shoe, said parking brake apparatus comprising:
- (a) a locking cylinder device mechanically connected to the brake shoe hanger, said locking cylinder device having a normal release position in which braking forces on the brake shoe hanger are released, and being operable responsively to fluid pressure to an application position in which braking forces are applied to the brake shoe hanger;
- (b) fluid pressure supply means for supplying fluid pressure to said locking cylinder device for causing it to be operated to its said application position;
- (c) locking nut means in said locking cylinder device operable, when subjected to said fluid pressure from said fluid pressure supply means subsequently to operation of the locking cylinder device to its said braking position, to a locking position for maintaining the locking cylinder device in its said application position;
- (d) delay means interposed between said fluid pressure supply means and said locking nut means for allowing operation of the locking cylinder device to its said application position ahead of operation of the locking nut means to its said locking position;
- and
- (e) release valve means for effecting operation of said locking nut means to an unlocked position in which said locking piston device is released from its said application position.
Dependencies are inferred from the claim text.