Patent GB-667335-A (GB)
Title: Damping devices for railway trucks
Inventor: SETTLES JAMES CLINTON
IPC: B61F5/12
Filed: 1950-03-20
Abstract: 667,335. Friction dampers; rail-vehicle undercarriages. BUCKEYE STEEL CASINGS CO. March 20, 1950, No. 6915/50. Classes 103(vi) and 108(iii). A damping mechanism for the bolster of a rail truck, comprises a side frame including a spring seat, a bolster, boxshaped in cross-section arranged for guided vertical movement relative to the side frame, springs supporting the bolster on the spring seat, a vertical friction surface at a side of the bolster, a member extending upwardly from the spring seat and inclined to the horizontal, a guide column including a web inclined to the vertical and converging towards the friction surface, a wedge having two flat surfaces arranged at an angle to each other corresponding to the angle between the web and the friction surface, one surface of the wedge being arranged along the inclined web and the other surface of the wedge being arranged along the vertical friction surface and a helical spring engaging the wedge at one end between the wedge and the upwardly extending member, urging the wedge upwardly into engagement with the inclined web and the vertical friction. surface. In the arrangement shown, each vertical side face 22 of an end portion 10 of a bolster 9, co-operates with a vertically disposed surface 16 of a friction wedge 14 which is urged into engagement by a spring 28, with the surface 16 and an inclined surface 19 of a web 18, carried on a guide column 12 extending between upper and lower frame members 50 and 51 respectively. The surface 19 of the web is slightly convex to permit tilting movement of the bolster. A wear plate 21 may be provided between the bolster-end face 22 and the wedge surface 16. The spring 28 bears on a tie member 31 within the wedge 14 and extends between a pair of tie bars 37. Openings 34 and 35 in the outboard and inboard walls 36 and 39 respectively of the guide column 12, permit compression of the spring 28, during assembly or dismantling of the bolster, by means of a bar prying against the tie bars 37, the spring being retained under compression by means of pins inserted in holes 38 in the walls 36 and 39 and co-operating with the upper surfaces of the tie bars 37. Lugs 76 and 77 projecting within the wedge 14, from the walls 36 and 39 respectively, prevent the wedge from dropping in the event of breakage of the spring 28. Each end portion 10 of the bolster is supported on a seat 42 on the frame member 51 by a group of springs 52. In assembling the truck, each wedge 14 is placed in position over its corresponding spring 28 in the guide column 12 and the spring is then compressed by applying pressure against the vertical face of the wedge by means of, for example, a jack applied between the vertical faces of opposite wedges. Each wedge is held in a position below its normal operative position by means of a pin inserted through the hole 38 and engaging a tie bar 37. The end portion 10 of the bolster is then inserted through the bolster opening in the frame, bolster lugs 44 aligned with a bolster opening portion 43 and the bolster thereafter lowered on to springs 52. A pinch bar is then inserted in the opening 34 to retract the wedge and the pin is withdrawn from the hole 38. An upstanding lip or rib 78 on each tie bar 37 locates the inner end of the pinch bar and assists to strengthen the tie-bar. The friction wedges 14 are reversible.