485,343. Wobbler mechanism. HULSEBOS, W., and NAAMLOOZE VENNOOTSCHAP HULSEMO. June 24, 1937, No. 17629. [Class 80 (iii)] In wobbler mechanism of the kind in which the longitudinal thrust of the pistons or plungers is taken by an annular pressure surface on the wobbler rolling on an annular pressure surface on the fixed frame of the mochanism, e.g. as described in Specification 440,545, that part of the pressure surfaces intended to resist outward radial loads is so shaped as to make an angle with the inclined crank-pin which is not less than twice the angle of friction between said surfaces. The wobbler 4 on the crank-pin 3 has a hardened steel pressure member 7 co-operating with a pressure member 8 also of hardened steel secured to the frame with a ring 9 interposed.; The pressure member 8 has two portions of straight profile viz. an outer portion 8, Fig. 3, substantially at right angles to the axis of the crankshaft 2, and an inner portion 8 which is conical so that the corresponding surface on the pressure member 7 makes an angle alpha with the axis of the crank-pin 3 which is not less than 12 and preferably about 15 . The surface 8 takes the longitudinal component N, Fig. 3, and the surface 8 the component R of the load kr between wobbler and frame. In a modification, the surfaces of the pressure members are formed as two continuous curves. Specification 350,308 also is referred to.