GB972767A - Improvements in adjustable cam devices - Google Patents

Abstract

972,767. Cams ; fluid - pressure brakes. WESTINGHOUSE AIR BRAKE CO. March 16, 1961 [March 16, 1960; April 28, 1960], No. 9638/61. Headings F2F and F2K. In an adjustable face cam, particularly for operating a follower 23, Fig. 1, on the stem of a self-lapping valve 5 in a railway braking system, the cam surface 22, Fig. 2, having a low point 40 and a high point 41, is formed on the face of a plate 12 coupled to a plate 9 fixed to an actuating shaft 2, the plate 12 being adjustably tilted relative to the plate 9 by a wedging surface on a screw 30 engaging a lip 32 on the plate 12. The lip 32 extends for approximately 180 degrees and enters a corresponding recess 34 in the plate 9 to bear against the screw 30 and against a radial pin 28. A third bearing point is provided by a round-headed pin 25, Fig. 1, and the plate 12 is pressed against the three equi-spaced bearing points by a rubber bush 14 in a bore in the plate, the bore having a spheroidal or other shape to allow tilting. The plates 9, 12 are coupled for rotation by a radial pin 36 engaging a notch in the lip 32. The shaft 2 has a number of radial cams 4 (not shown in full) actuating further valves in the braking system as the handle 7 is moved through its operating angle, the screw 30 allowing adjustment of the valve 6 relative to this angle. The handle may be moved beyond this angle to a first position wherein a cam 19 on the face of the plate 9 actuates an emergency brake valve 6 and to a second position wherein the handle 7 may be removed, leaving the brakes applied. As shown in Fig. 2, the screw 30 is adjacent the high point 41 of the cam 22. In a modification, Figs. 5- 8 (not shown) a second adjusting screw is provided adjacent the low point of the cam, the radial pin 28 and rubber bush 14 being omitted and the round-headed pin 25 is replaced by a compression spring urging the plate 12 against a spheroidal bushing on the shaft 2.