Patent GB-544335-A (GB)
Title: Positively and progressively acting speed varying device
IPC: F16H3/42
Filed: 1939-09-11
Abstract: 544,335. Variable-speed gearing. BESCHKINE, L. Sept. 11. 1939, No. 25574. Convention date, Sept. 9, 1938. [Class 80 (ii)] The. driving-shaft is provided with elliptical or like wheels gearing continuously with similar wheels mounted on the driven shaft and adapted to be successively coupled thereto during equal arcs of movement, change of speed being effected by adjusting the. relative angular position of each pair of wheels. The pairs of wheels may constitute epicyclic trains. In the mechanism shown in Fig. 1. elliptical wheels 1, 2, 3, 4 on the driving-shaft P, connected to the motorshaft M, engage similar wheels 1<SP>1</SP>, 2<SP>1</SP>, 3<SP>1</SP>, 4<SP>1</SP> on the driven shaft R. The wheels 1, 3 and 2, 4 are secured to 'sleeves m<SP>1</SP>, m<SP>2</SP> having helical grooves co-operating with helical ribs h<SP>1</SP>, h<SP>2</SP>, respectively, on the driving-shaft. The wheels 1' .. 4' are loose on the driven shaft and are provided with magnetic clutches e<SP>1</SP> . . e<SP>4</SP> in circuit with brushes b<SP>1</SP> . b<SP>4</SP> which engage successively a segment 9 on the motor-shaft. During each revolution of 'the driving-shaft, the wheels 1<SP>1</SP> . . 4<SP>1</SP> are coupled during successive quarter- 'revolutions, and the driven shaft is driven at a substantially uniform speed. To change speed, the driving shaft is moved longitudinally by means of a lever L, and the ribs h<SP>1</SP>, h<SP>2</SP> rotate the wheels and thereby adjust the relative angular position of 'each pair thereof. The wheels are provided with counterweights 12. The pairs 3, 3<SP>1</SP> and 4, 4<SP>1</SP> of wheels may be replaced by fly-wheels. To suppress slight periodical variations in the speed of the driven shaft, spiral wheels and spiral intermediate wheels may be employed. In the mechanism shown in Fig. 4, a single spiral-wheel a' on the driving-shaft M engages spiral wheels a2, a<SP>1</SP>2 on sleeves i2, i<SP>1</SP>2 mounted on shafts I, I<SP>1</SP>. Other sleeves i3, i<SP>1</SP>3 are provided with spiral wheels a3, a<SP>1</SP>3 engaging spiral wheels a4, a<SP>1</SP>4 on a sleeve 13 which is coupled by an epicyclic train V to the driven shaft R. Reversal can be effected by the epicyclic train. The wheels a4, a<SP>1</SP>4 are provided with magnetic clutches 14, 24 arranged to 'couple the wheels 'to the sleeve 13 during successive half-revolutions. The shafts I, I' are provided With straight splines j2, j<SP>1</SP>2 and helical splines j3, j<SP>1</SP>3 co-bperating with corresponding groves in the associated sleeves. The shafts I, I' are moved longitudinally to adjust the relative angular positions of the wheels, and thereby change speed from neutral to that of the shaft M. For this purpose, a gear-lever is coupled to forks 35, 36 which engage resiliently the shafts I, I<SP>1</SP>. The gear-lever can also be moved into position for engaging a clutch 37 with the sleeve 13 to provide direct drive. In a modification shown in Fig. 8, elliptical wheels A4, A<SP>1</SP>4 on the driving shaft M engage intermediate elliptical wheels A3, A<SP>1</SP>3, in connection with other intermediate elliptical wheels A2, A'2 engaging on elliptical wheel A1 which is secured to the annulus of an epicyclic train V for driving the driven shaft R. The wheels A4, A'4 are each provided with a mechanical clutch consisting of spring-urged, pivoted jaws 57 co-operating with a flange 62. The jaws are automatically opened during successive half-revolutions by means of a rocking cam 54 in connection with a sleeve 51 which is reciprocated by means of a rock-arm 50 and a grooved sleeve 48 on the shaft I. Alternatively, the clutch-cams 64 can, as shown in Fig. 11, be operated by means of rock-arms 63, 70 mounted on the wheels a4, a'4 and co-operating with tracks 65, 71 containing spring-urged slides 66, 71<SP>1</SP> which are retracted by means of cams 73, 68. on the wheels. In the mechanism shown in Fig. 12 planetary elliptical wheels A2, A<SP>1</SP>2, A3, A'3 are mounted on a carrier Y on the driving- shaft M. The wheels A2, A<SP>1</SP>2 co-operate with a wheel A' on the driven-shaft R, and the wheels A3, A<SP>1</SP>3 co-operate with wheels A4, A<SP>1</SP>4 which are locked during alternate half-revolutions by means of electromagnets 74, 75 in circuit with contacts on the carrier Y.