US 4,033,629 A · Automatic freight car brake apparatus with spring-applied fluid-pressure-released hand brake

Abstract

The usual brake cylinder in a conventional freight car brake apparatus is replaced by a novel cylinder that embodies a pair of pistons and a spring of sufficient strength to effect a hand brake application. Conventional brake applications and releases are effected accordingly as the usual brake control valve effects the supply of fluid under pressure to and the release thereof from one of the two pistons which are connected to a common piston rod through which force is transmitted to brake applying brake shoes. The second piston is subjected on one side to the force of the spring and on the other side selectively to brake pipe pressure or pressure in a hand brake release reservoir that is charged from the brake pipe to a higher pressure by an air-driven air booster operated by air from the brake pipe. Thus, the spring is enabled to effect a hand brake application in the absence of fluid under pressure acting on the other side of the second piston. This application may be released by the supply of fluid under pressure to this other side of the second piston from either the release reservoir or the brake pipe, or some other independent source.

Claims21

Dependent claims

In a vehicle combined fluid pressure and hand brake apparatus including a normally charged brake pipe, an auxiliary reservoir, an emergency reservoir and a fluid pressure operated brake control valve device operable responsively to variations of pressure in the brake pipe to effect fluid pressure brake applications and brake releases, said brake apparatus comprising:

a. fluid pressure operated means for effecting a brake application on the vehicle and a subsequent brake release responsive to operation of the brake control valve device to effect the supply of fluid under pressure from one or both of said reservoirs to said fluid pressure operated means and the release of fluid under pressure therefrom,
wherein the improvement comprises;
b. a brake release reservoir,
c. means for effecting charging of said brake release reservoir to a pressure higher than that in the normally charged brake pipe,
d. spring means for causing a brake application on the vehicle independently of the operation of the brake control valve device,
e. fluid motor means operable in response to the supply of fluid under pressure thereto to render said spring means ineffective to cause a brake application on the vehicle, and
f. means whereby fluid under pressure may be supplied to said fluid motor means from any one of a plurality of sources of fluid under pressure.

4 more elements

For use with a vehicle combined fluid pressure and hand brake apparatus including a normally charged brake pipe, an auxiliary reservoir, an emergency reservoir and a fluid pressure operated brake control valve device operable responsively to variations of pressure in the brake pipe to effect the supply of fluid under pressure from one or both of said reservoirs for effecting a brake application and the release of said fluid under pressure to effect a brake release, a brake applying means to which said fluid under pressure is supplied for effecting a brake application on the vehicle, said brake applying means comprising;

a. a pair of telescopically arranged cup-shaped cylindrical members, each having a bore therein coaxial with the longitudinal axis of said members and cooperating one with the other to form therebetween a first chamber to which fluid under pressure may be supplied by the brake control valve device,
b. a piston slidably mounted within the inner one of said pair of cylindrical members and cooperating therewith to form a second chamber to which fluid under pressure may be supplied from the brake pipe,
c. a piston rod secured at one end to one side of said piston and extending through said bore in each of said telescopically arranged cylindrical members, said piston rod being rigidly secured to the outer one of said pair of cylindrical members, whereby a braking force is transmitted to said piston rod in response to the supply of fluid under pressure to said first chamber,
d. a piston stop member secured to said inner cylindrical member, and
e. spring means disposed in said inner cylindrical member and interposed between said piston stop member and the other side of said piston, said spring means being effective in the absence of fluid under pressure in said second chamber to transmit a brake applying force to said piston rod via said piston for effecting a brake application on the vehicle independently of the operation of the brake control valve device.

2 more elements

Dependencies are inferred from the claim text.

Automatic freight car brake apparatus with spring-applied fluid-pressure-released hand brake

Life of this patent

Automatic freight car brake apparatus with spring-applied fluid-pressure-released hand brake

Life of this patent

Abstract

Claims21