GB1273440A - A combined buff and draw gear for central buffer couplings on railway vehicles - Google Patents

Abstract

1,273,440. Combined buff and draw gear. RHEINMETALL G.m.b.H. 3 Nov., 1969 [15 Nov., 1968], No. 53687/69. Heading B7T. Combined buff and draw gear for a railway vehicle centre buffer coupling comprises a housing 4 having slidably mounted in one end a member 7 connected to the coupling and projecting inwardly therefrom an hydraulic damper cylinder 8 which co-operates with a piston connected with a cap 5 at the opposite end of the housing, there being coaxial with the damper three columns I, II, III of friction springs, wherein during buff all the columns are effective together with the damper, but during draw only columns I and II are effective. During buff, pressure from the coupling is transmitted successively through a web 9 of slide member 7, a slide ring 22, column I, ring 23, column II, ring 18, bush 16, intermediate tube 12, ring 15, column III to body 19 with a stop ring 21. Also some of the force is absorbed by the damper with fluid from space 8a flowing through passages 25 past valve 26 and through passage 27. The column III will be fully compressed first when the end of flange 17 abuts stop flange 24, the column II will become fully compressed, second when ring 23 abuts the end of bush 16, with the column I fully compressed last. On the return stroke fluid passes from space 10a to space 8a through valve 28. Upon draw loading, the damper is hardly effective since fluid passes only through return valve 28 with the force being transmisted successively through web 9, tube 14, tube 12, bush 16, ring 18, column II and ring 23 and column I to ring 22 abutting portion 6 of the housing comprising an end stop. The column III is not utilized and column II becomes fully compressed before column I. A fluid reservoir 31 is connected to space 10a.