GB485169A - Improvements in cam mechanism - Google Patents

Abstract

485,169. Cam mechanism. EDLIN, G. S., and PAGET, SIR R. A. S. Nov. 12, 1936, No. 30884. [Class 80 (iii)] Cam mechanism for converting rotary into reciprocating motion or vice versa, comprises an annular cam the inner and outer surfaces of which lie on the surfaces of two concentric spheres, and having a number of rises and hollows, and one or more antifriction devices providing line contacts or the equivalent transverse to the cam track and means for permitting the antifriction devices to vary their angle in the plane through the vertical axis of the cam and to vary their distance normal to said axis. A number of cylinders 1 each contains a piston 2 actuating a conical roller 6 bearing on the annular cam surface 7 having flanges 8 and forming part of a spherical shell 7<1> having its centre at 9. Each piston has a pair of oppositely placed lugs 3 forming a bearing for a gudgeon 4 on which is slidably mounted a spherical bearing 5 which forms a universal support for the roller 6. This mounting may be replaced by a gimbal mounting. The cam track is so formed that a straight line drawn transversely across it at any point would pass through the point 9. The cam shown has two rises and two hollows and further, the apex of the roller is at the point 9 so that true rolling motion is obtained. The cam is keyed to a shaft 10. Guide plates 11 resist forces tending to rock the pistons at right-angles to the plane of the Figure, and plates 13, 13<1> resist rocking in said plane. To maintain the roller in constant contact with the cam track, the plate 13<1> has a socket 14 which supports a ball 15 on which bears a secondary cam 16 mounted on the shaft 10 and loaded by springs 17. The roller may be replaced by an equivalent member, the flanges 8 on the cam may be dispensed with and the cam may be stationary.