US 4,793,446 AGranted

Single-cylinder, truck-mounted brake assembly

AssigneeAmerican Standard Inc.

InventorsJames E. Hart, William K. Mong, Allen W. Kyllonen, Mark S. Krampitz

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Abstract

A single-cylinder, truck-mounted brake assembly for a railway vehicle truck in which low-cost, lightweight, truss-type brake beams are employed, with one beam having the single brake cylinder mounted thereon. Force-transfer levers pivotally-mounted to the respective brake beams at the beam-midpoint are interconnected by force-transmitting members that pass through openings in the bolster to move the brake beams into brake shoe/wheel engagement when a brake application is made. The brake rigging is set up so that the transfer lever bail imparted to the force-transmitting members is split. With respect to the force-transfer lever connected to the one force-transmitting member (brake cylinder), this has the effect of the brake cylinder piston skewing equally on opposite sides of the cylinder centerline to prevent piston seal leakage. In addition, diagonally-opposed lever arms of the respective force-transfer levers are greater in length than the other lever arms to obtain brake force multiplication without unbalancing the brake shoe forces. A further advantage found by making the one transfer lever arm longer than the corresponding lever arm of the other transfer lever is to split the lateral swing of the other force-transmitting member (slack adjuster) equally on opposite sides of the centerline of the bolster opening to avoid interference therebetween.

Claims27

Dependent claims

For a railway vehicle truck having a longitudinal axis, a transverse axis perpendicular thereto, a pair of wheel/axle units parallel to said transverse axis, a bolster so disposed between said pair of wheel/axle units that its axis coincides with said transverse axis, said bolster having first and second openings spaced equidistantly on opposite sides of said longitudinal axis and passing through said bolster in a direction parallel thereto, a brake rigging comprising:

(a) first and second brake beams interposed between said bolster and a respective one of said wheel/axle units so as to be in substantially parallel relationship with said bolster, said first and second brake beams having brake shoes carried thereon adjacent the wheel treads of said wheel/axle units for engagement therewith when said brake beams are spread apart;
(b) first and second transfer levers pivotally-connected, respectively, at a point intermediate the ends thereof to said first and second brake beams, each said transfer lever forming first and second lever arms, the effective lengths of said first and second lever arms of at least one of said first and second transfer levers being dissimilar;
(c) first force-transmitting means passing through said first opening of said bolster for connection with said first lever arms of said first and second transfer levers, said first force-transmitting means including force actuator means for effecting rotation of said first transfer lever;
and
(d) second force-transmitting means passing through said second opening of said bolster for connection with said second lever arms of said first and second transfer levers to effect rotation of said second transfer lever, whereby a force is exerted on said first and second brake beams, at said pivotal connection of said first and second transfer levers therewith, in opposite directions.

2 more elements

(a) first and second brake beams interposed between said bolster and a respective one of said wheel/axle units so as to lie in substantially parallel relationship with said bolster, said first and second brake beams having brake shoes carried thereon adjacent the wheel treads of said wheel/axle units for engagement therewith when said brake beams are spread apart;
(b) first and second transfer levers pivotally-connected, respectively, at a point intermediate the ends thereof to said first and second brake beams so as to form first and second lever arms of said transfer levers;
(c) first force-transmitting means comprising:
(i) a brake cylinder body mounted on said first brake beam,
(ii) a fluid-pressure-actuated piston operably-disposed within said brake cylinder body, said piston having a "release" position in which said brake shoes are disengaged from the wheel treads of said wheel/axle units a predetermined distance, a "nominal brake application" position in which said brake shoes are moved said predetermined distance into engagement with the wheel treads of said wheel/axle units, and a "maximum brake application" position corresponding to the maximum stroke of said piston,
(iii) a push rod connected at one end to said piston and at the other end to said first lever arm of said first transfer lever, such that when said piston is in said "nominal brake application" position, said first transfer lever lies in an "optimum" position substantially parallel to said transverse axis, whereby said first lever in said "release" position is angularly-displaced in one direction from said "optimum" position a given number of degrees and in said "maximum brake application" position is angularly-displaced said given number of degrees in the opposite direction from said "optimum" position, thereby substantially splitting the bail of said first transfer lever, and
(iv) a connecting rod passing through said firt opening of said bolster having one end connected to said first lever arm of said second transfer lever, and the other end abutting said brake cylinder body;
and
(d) second force-transmitting means passing through said second opening of said bolster for connection with said second lever arms of said first and second transfer levers to effect rotation of said second transfer lever, whereby a force is exerted on said first and second brake beams at said pivotal connection of said first and second transfer levers therewith in opposite directions.

6 more elements

Dependencies are inferred from the claim text.