Patent GB-321645-A (GB)
Title: Rotary internal combustion engines
IPC: F02B75/26
Filed: 1928-05-10
Abstract: 321,645. Coltman, M. G. H., (Ezbelent, G.). May 10, 1928. Movable-abutment type; regulating. - The stroke amplitude of a rotary internal-combustion engine can be varied, whether running or not, by providing means to displace, along a slot in an arm actuating the piston rod, one end of a connecting rod which is attached to a crank on a planet pinion which effects the requisite motion of the piston. The engine shown in Figs. 1 (1868/29) and 2 (1868/29) comprises a number of curved cylinders carried by a framework 12 fixed to a driving shaft 3; the pistons 4 thereof are actuated by a connecting rod 6 pivoted to a crank on a crankshaft 7 which carries a number of pinions 18 - - 20 meshing with gears 21 - - 23 freely mounted on the driving shaft 3. Any one of the gears 21 - - 23 may be locked by a brake acting on corresponding drums 24 - - 26 to vary the number of strokes per revolution of the driving shaft 3. Variation in the stroke amplitude is obtained by adjusting the point of connection 8 of the connecting rod 6 to the piston-carrying arm 5 which is provided with a slot 13 to receive the pivot connection 8 which is linked to an arm 11 manually adjusted by a sliding collar 15 on the driving shaft through links 16. The crankshaft 7 drives a camshaft 31 to control the ignition and the valve rocker-arms. These latter are actuated by a cam 34 through rollers 35 on an arm 36 pivoted to a lever 41 which is freely mounted on the camshaft 31 but in order to maintain the valve timing constant is adjusted in angular position corresponding to the setting of the arm 11 by a pin and slot connection 46 with an extension 42 of this arm 11; the form of the slot may, however, be such as to vary the timing. The adjustment of the sliding collar 15 and the braking of the corresponding gear wheel may be simultaneously effected by a linkage. Figs. 1 (Comp.) and 2 (Comp.) show a construction of engine with straight cylinders. The position of the point of connection 37 of the connecting rod 11 to the slotted arm 9 of the piston-carrying arm 7 is cyclically varied so that the strokes are of unequal length in the cycle. A lever 16 has pivoted thereto a V-shaped lever 14 one arm of which is attached by a link 12 to the point of connection 37 and the other carries a roller 21 moving in a groove in a cam 20 which is mounted on the crankshaft 10 and driven from the half speed camshaft 23. Adjustment of the lever 16, and therefore of the point of connection 37, is effected by a sliding collar 19 on the driving shaft which at the same time brakes the appropriate gear wheel of the epicyclic piston actuating mechanism 31, 31a, 39, 32, 32<a>, 38. Independent adjustment of the compression ratio is effected by a nut and screw device 24 whereby the pistoncarrying arm 7 is moved relatively to the slotted arm 9; this is done through a link 25 attached to a second sliding collar 26, The braking of the gear wheels may be differential, i.e. increasing on one gear wheel and decreasing on the other, for instance by means of a valve throttling the delivery of one pump and opening that of a second pump driven by the respective gear wheels. The form of the slot in the piston-carrying arm may be such as to give a variation in the compression ratio.