The Westinghouse Friction Draft Gear

Operation WHEN, either in draft or in buffing, the stress upon the draw-bar moves the follower plates, A or Z, Fig. i, toward each other, the preliminary spring, C, is compressed, and if the pressure so applied is less than is required to force the follower plate, A, against the release pin, M, the segmental carriers and wedge bars remain at rest. The capacity of this spring is about 20,000 pounds and is sufficient to provide for a large percentage of the draw-bar movements, thus greatly relieving the frictional element from motion and consequent wear. When, however, the stress exceeds the capacity of the preliminary spring sufficiently to push the follower, A, against the ends of the segmental carriers, it will have forced the release pin, M, which projects slightly above the segmental carriers, toward the closed encl of the cylinder, thereby relieving the pressure of the auxiliary release spring against the small end of the wedge. In this position the force necessary to compress the springs, C and (9, is exerted against the large end of the wedge, and by the inclined surfaces it is transmitted through the segmental carriers to the wedge bars. A further increase of force against the follower plate, A, puts the segmental carriers and wedge bars into motion, and in so doing the force exerted by the wedge upon the wedge bars produces friction between the wedge bars and the V-shaped grooves of the cylinder (which is tapered toward the closed end). The traverse of the wedge bars is completed when the follower, A, comes in contact with the encl of the cylinder, the release springs, K and Z, having been compressed to about 80 per cent, of their capacity. The complete movement of both spring and frictional elements results in a total resistance of about 140,000 pounds. 27