GB797511A - Improvements in and relating to variable speed gear - Google Patents

Abstract

797,511. Variable-speed gear. PIETRASZEWSKI, B. Oct. 11, 1954 [Oct. 10, 1953], No. 27917/53. Class 80 (2). Friction cones 16, 17 on parallel input and output shafts 13, 15, with their bases opposite and their adjacent generatrices parallel and forming a gap of constant width, are drivingly connected by one or more double-coned friction idlers 18, 19, which, to vary the speed ratio, can be traversed axially along guide-rods 23, 26 which maintain the idler axes parallel to and offset from the cone gap. The idlers 18, 19 are carried respectively by two relatively slidable tubes 20, 21 which can be urged apart in opposition to an internal engaging spring to spread the idlers out of engagement with the cones by turning relatively to one another by handles 34, 33, an outer sleeve 32, having diametrically opposite end cam recesses 32a, 32b engaging pins 29, 30 fast with the respective idler tubes 20, 21, and an inner sleeve 31 having axial slots receiving the pins 29, 30. The sleeve 31 is mounted on a suitably slotted guide sleeve 25 which slides on the guide rod 26. With the idlers thus disengaged from the cones they may be slid axially together on the guide rods 23, 26 for ratio change, or alternatively a precessional idler shift may be made by turning both sleeves 31, 32 together to cause the idlers to become inclined about the transverse axis, thus inducing axial shift. In an hydraulically controlled form, Fig. 11, fluid pressure supplied to one or other of two lines 56, 57 by manually reciprocating a piston 36 through a rack-and-pinion 39, passes to a selector valve 58 which can be set to supply the pressure simultaneously to two pistons 45, 46 for pressing the idlers 18, 19 into engagement with the cones 16, 17 in opposition to release springs 47; or to either of two pistons 52, 54 for shifting the idler-carrier 41 axially to vary the speed ratio.