Compression type railroad brake slack adjuster

Abstract

A railroad slack adjuster has a threaded adjusting screw, one end of which is adapted to be connected to one portion of a railroad car brake rigging. The slack adjuster also has a clutch housing assembly, telescopic with the adjusting screw and adapted to be connected to another portion of the brake rigging. A clutch disk is rotatably mounted on the adjusting screw for engagement with opposing clutch surfaces within the clutch housing. A trigger housing is telescopically positioned about the adjusting screw, clutch housing and clutch disk. A spring is positioned about the adjusting screw and effective between the clutch housing and adjusting screw to urge the screw outwardly of the clutch housing. There is a further trigger spring positioned about the clutch housing and urging the clutch housing outwardly of the trigger housing. A brake application applied at opposite ends of the slack adjuster to the adjusting screw and clutch housing causes the clutch disk to move between the opposing clutch surfaces as the slack adjuster lets out and takes up slack in the brake rigging during application and release of the brakes.

The embodiments of the invention in which an exclusive property or privilege is claimed are described as follows: 
     
       1. A compression type slack adjuster for use in a railroad brake, the brake rigging being arranged such that during application of the brakes the slack adjuster is in compression, comprising: a clutch housing assembly having first and second opposed clutch surfaces formed therein and a first clevis affixed to one end of the housing, the other end being open;   an adjusting screw assembly having a threaded end fitting telescopically in the open end of the clutch housing, the other end of the screw assembly having a second clevis affixed thereto;   a clutch disc rotatably mounted on the adjusting screw threads and disposed between the first and second clutch surfaces;   a trigger housing surrounding at least a portion of the clutch housing and having a bracket attached thereto;   a main spring engaging the adjusting screw assembly and the clutch housing assembly, urging the first and second clevises apart;   a trigger spring bearing against the clutch housing and the trigger housing, urging the trigger housing and clutch housing apart;   a plurality of clutch pins slidably mounted in the clutch housing assembly and engageable between the trigger housing and clutch disc so as to transmit the trigger spring force to the clutch disc;   an actuator rod having a stop collar, the rod being connectable to the brake rigging and slidable in the bracket with the bracket between the stop collar and the brake rigging, the stop collar and bracket being engageable upon sufficient relative separation of the rod and trigger housing to compress the trigger spring and remove the trigger spring force from the clutch pins; and   a lockup spring disposed between the clutch housing and clutch disc to apply a force to the clutch opposite that applied by the trigger spring.   
     
     
       2. The slack adjuster of claim 1 further characterized in that the clutch disk engages thrust bearings on either side of it to permit it to rotate on the adjusting screw. 
     
     
       3. The slack adjustor of claim 1 further characterized in that the clutch housing comprises an elongated tube rigidly connected to a clutch body member. 
     
     
       4. The slack adjuster of claim 3 further characterized in that the first clutch surface is formed on the tube and the second clutch surface is formed on the clutch body member. 
     
     
       5. The slack adjuster of claim 3 further characterized in that the clutch body member includes an extension having a hexagonal outside cross section. 
     
     
       6. The slack adjuster of claim 5 further characterized in that the trigger housing includes a tubular shell having an end piece with a hexagonal opening engaging the clutch body extension so as to prevent rotation of the trigger housing on the clutch housing. 
     
     
       7. The slack adjuster of claim 5 wherein the trigger spring is coaxially positioned about the clutch body extension. .Iadd. 
     
     
       8.  A compression-type slack adjuster for use in brake rigging arranged such that during application of the brakes the slack adjuster is in compression, comprising: a clutch housing assembly having first and second opposed clutch surfaces formed therein and adapted at one end to be attached to a portion of a brake force transmitting means, the other end being open;   an adjusting screw assembly having a threaded end fitting telescopically in the open end of the clutch housing, the other end of the screw assembly being adapted to be attached to another portion of the brake force transmitting means;   a clutch disc rotatably mounted on the adjusting screw threads and disposed between the first and second clutch surfaces;   a trigger element adjacent a portion of the clutch housing;   main spring means engaging the adjusting screw assembly and the clutch housing assembly and urging said assemblies in opposite directions;   a trigger spring bearing against the clutch housing assembly and the trigger element and urging the trigger element and clutch housing assembly in opposite directions;   a plurality of clutch pins slidably mounted in the clutch housing assembly and engageable between the trigger element and clutch disc so as to transmit the trigger spring force to the clutch disc;   a brake application force applied to said clutch housing assembly by said brake force transmitting means moving said clutch housing assembly, trigger element and adjusting screw assembly in a brake application force transmitting direction, means for limiting movement of said trigger element, with subsequent brake application force movement compressing said trigger spring and removing the trigger spring force from the clutch pins; and   a lock-up spring disposed between the clutch housing assembly and clutch disc to apply a force to the clutch disc opposite that applied by the trigger spring. .Iaddend. .Iadd.   
     
     
       9.  The slack adjuster of claim 8 further characterized in that said trigger element is a housing having a bracket attached thereto, the means for limiting movement of said trigger housing including an actuator rod having a stop collar, the rod being connected to the portion of the brake application force transmitting means and slidable in the bracket with the bracket being between the stop collar and the brake application force transmitting means. .Iaddend.