Patent GB-405647-A (GB)
Title: Improvements in or relating to variable-speed gearing
IPC: F16H9/26
Filed: 1932-08-05
Abstract: 405,647. Variable - speed gearing. PIERCEY, M. W., 1441A, London Road, Norbury, London. Aug. 5, 1932, No. 22022. [Class 80 (ii).] An infinitely variable epicyclic change-speed gear comprises several coned friction rollers 23, Fig. 1, engaged by three members 25, 26, 28 on the same side of the axis of rotary motion of the rollers, one of the members 25 being connected to the driving-shaft 10, another 28, which is capable of relative axial movement to alter the transmission ratio, being connected to the driven shaft 11, and the third 26 being stationary. Each roller comprises four parts, a cone 21 driven by the annulus 25, a rolling cone 22 engaged by the fixed annular track 26, a cone 23 of opposite conicity which has a generating line 24 parallel to the axis of the shafts 10, 11 and drives the annulus 28, and a cone 20 which is a continuation of the driven cone 21. The cones 21 may be driven by a sun cone in which case, the parallel generating line 24 is on the inside of the cones 23 and the members 26, 28 are also located inwardly of the rollers. The annulus 28 is carried on a sleeve 31 which is splined on a sleeve 32 connected to the driven shaft, and reciprocated by a striker 34 and screw means 36. The rollers are carried in a cage 17, 18 and engaged by the parts 14, 14a of an idler sun cone 12, between the shaft 10 and which a thrust bearing 16 is mounted. With the annulus 28 on the section F of each driving cone which is cut by the projection of the driven cone 21, the maximum forward speed equal to that of the shaft 10 is obtained. At the section N which similarly marks the intersection with the projection of the rolling cone 22, the shaft 11 is stationary and at the section R, the maximum speed in reverse is obtained. Known self-tightening devices comprising interengaging cam-like projections 29, 30 are located between the track 26 and the stationary part 26a and between the annulus 25 and a disc 39 carried by the driving-shaft respectively. The member 26a is engaged by a brake 82 which slips on overload. In a modification for motor vehicles, the sleeve 32 and the driven shaft are connected by a cardan joint and a dog clutch, and the annulus 26 is formed on the inner member of a cone clutch which is eased off the outer member thereof by the annulus 28 in the full forward driving position so that the rollers cease to rotate about their own axes. In a further form for machine tools, the small cones 20, Fig. 1, correspond to the driven cones, and the rolling cones are located between the driven and driving cones but have their bases adjacent the bases of the latter. In Fig. 8, the cones 60 have their axes parallel and are engaged by a belt 80 passing round a drum 78 of opposite conicity, the belt being operable by a striker 81 to vary the speed taken off by the shaft 77. Each cone has two pulleys 71, 72 integral therewith, one set, 71 or 72, being engaged by a driving-belt and the other set, 72 or 71, by a stationary belt having a tensioning device. In a form described in the Provisional Specification, the roller cage is driven directly by the driving-shaft and the rollers which are engaged by a reciprocable non-rotating annulus or belt have spur gears at their ends which engage a ring gear inside a pulley. In a modification of this form, a single endless belt passes over two reciprocable jockey pulleys, so that two runs of the belt engage the rollers edge to edge.