Patent GB-1176761-A (GB)
Title: A Hand Brake for Railroad Cars
Inventor: ANDONIAN PIERRE JOSEPH
IPC: B61H13/04
Filed: 1968-04-16
Abstract: 1,176,761. Railway brake-operating mechanism ; friction clutches. CARDWELL WESTINGHOUSE CO. 16 April, 1968 [13 April, 1967], No. 17965/68. Headings F2C and F2E. A hand brake for a railroad car comprises an operating shaft 17, 64, 19, extending across the width of the car and provided at either end with a hand wheel 21, 23, which is coupled to a winding drum 30, Fig. 3, forming part of the brake-operating mechanism 12, Fig. 1, the coupling between the drum and shaft being releasable by a mechanism coupled to a second shaft 20, 124, 127, also extending across the width of the car and provided at either end with a hand lever 29, 31. General arrangement.-The mechanism 12 includes a chain 49 which is connected to the drum 30 to be wound thereon to engage the brakes, and is connected via lever 35, rod 45, lever 41 to the brake-operating cylinder 43. The drum is driven by rotation of a pinion 62, rotatably mounted on the shaft 64, via gearing 34 on a flange 32 on the drum and gearing 90 on the pinion, the shaft 64 and pinion 62 being coupled by a friction clutch arrangement including a clutch collar 92 on the pinion having a conical friction face 94 which co-operates with a complementarily-shaped friction face 95 on a ratchet wheel 96. A similar friction face 98 on the ratchet wheel co-operates with a complementarily-shaped friction face 100 on a nut 102 screwed on to the end of the pinion; the nut being provided with teeth which are engageable by a toothed clutch sleeve 108 slidable but non-rotatable on shaft 64. Thus, when the nut is engaged by the clutch sleeve and the shaft 64 is rotated, the nut is screwed along the pinion to force the nut, ratchet wheel and pinion into frictional engagement, the drum being then rotated. The brake is held in its engaged state by a latch (150), Fig. 4 (not shown), which is held by a camming member (170) in engagement with the teeth of the ratchet wheel. Controlled brake release.-Rotation of one of the hand wheels 21, 23 in the reverse direction causes the nut 102 to unscrew to release the frictional engagement between the pinion 62, nut 102 and ratchet wheel 96 so that, although the latch (150) is still engaged in the teeth of the ratchet wheel to prevent its backward movement, the pinion and therefore the drum rotate backwards as the hand wheel is rotated to release the brakes. Quick brake release.-Rotation of one of the hand levers 29, 31 and shaft 25, 124, 27 causes rotation of a hub 130, keyed to shaft 124, carrying a flange provided with a camming recess 144 in which a flange 120 of the clutch sleeve 108 is engaged, the flange and recess being arranged so that as a lever is rotated the sleeve 108 slides along shaft 64 out of engagement with the nut 102. Simultaneously the camming member (170), holding the latch in engagement with the ratchet wheel, is pivoted out of the way so that the ratchet wheel 96 becomes free to rotate backwards, the ratchet wheel, pinion and nut rotating backwards together to release the brakes. At the end of the release movement, rotation of the pinion is halted as the end of the chain 49 contacts a stop, but the nut continues to rotate relatively to the pinion, until halted by abutment of lugs (206), (204), Figs. 5 and 6 (not shown), on adjacent faces of the nut and the clutch collar, to disengage the frictional engagement of the ratchet wheel, nut and clutch collar. The hand wheel 21 is coupled to shaft 17 via gearing 250, 252 so that both hand wheels are turned in the same direction for a brake engage or release operation.