GB1104973A - Improvements in change speed gears - Google Patents

Abstract

1,104,973. Change-speed gearing. H. K. SCH€FER. 30 July, 1965, No. 32592/65. Heading F2D. In a change-speed gear comprising a first set of toothed bevel gears 3 forming a cone, and either a cylindrical gear 2 (Figs. 8, 9, not shown), or a second set of bevel gears 2 forming a second cone facing in the opposite direction to the first, connected by an axially movable hollow countershaft 33 on which are formed pinions 33<SP>1</SP>, 33<SP>11</SP>, for ratio change, the axis of rotation of the countershaft is moved in a circular orbit during which firstly the pinions 33<SP>1</SP>, 33<SP>11</SP> are moved out of mesh with the engaged gears 3, 2, secondly the countershaft is moved axially to align the pinion 33<SP>1</SP> with the next adjacent gear 3 and the pinion 33<SP>11</SP> with the next adjacent bevel gear 2 or with an adjacent band of the cylindrical gear, and finally the pinions 33<SP>1</SP>, 33<SP>11</SP> are brought into mesh with the gears 3, 2 with which they are aligned. The countershaft 33 is rotatably mounted on a non-rotatable sleeve 34 having a peg 13 which engages in a cam groove 10 on an eccentrically mounted control shaft 9 supporting the sleeve 34, the cam groove having alternate helical and circumferential sections 12, 11 of equal length so that rotation of the control shaft causes stepwise axial movement of the sleeve 34 and countershaft 33, combined with orbital movement thereof, each axial step corresponding to the spacing of adjacent bevel gears 3. A forked arm 35 engaging a fixed rod 36 prevents rotation of the sleeve 34, and a positive detent 18 on the control shaft handle locks the control shaft in a gear engaged position. The gear sets 2, 3 are mounted on shafts 26, 19 respectively, connected to input and output shafts 1, 32 by gear pairs 24, 25 and 30, 31 respectively. The pinions 33<SP>1</SP>, 33<SP>11</SP> may be similar or of different sizes.