Patent GB-862523-A (GB)
Title: Means for digitally varying rotational velocities
IPC: F16H37/00
Filed: 1957-04-09
Abstract: 862,523. Change-speed gear. COLLINS RADIO CO. April 9, 1957 [Sept. 7, 1956], No. 11591/57. Class 80 (2). A multi-ratio change-speed gear giving a large number of speeds to its output shaft, the numerical steps between succeeding ratios being the same, comprises a number of planetary gears of the simple sun-planetsring gear type in series, the output carrier of one planetary gear being fast with the sun gear of the following planetary gear which also receives drive from a main input source, controlling means selecting and indicating the exact ratio which with the final output shaft is driven. The controlling means may be manually actuated, or may be punched card, perforated tape, magnetic tape, &c. apparatus. The invention is applicable to driving lathes, gear hobbers, milling machines, tone wheels, audiofrequency generators, wind-tunnel blower drives and coil winders that can provide variablepitch winding. The general arrangement is shown in Fig. 1. The input is applied through a " harmonic velocity generator " H which drives a shaft 11. The planetary gear units A, B, C ... K are connected in series, the reaction sun gear of the first planetary gear unit A being stationary and its output Xb being fed into the second planetary gear unit B. The planetary gears A &c. are each fed from the common input shaft 11 through " velocity selection means " 12a ... 12k. The " velocity selection means " 12a &c. apply harmonics of the speed of rotation of the shaft 11 to the planetary gear units A &c. The harmonic velocity fed into each planetary gear is selected externally by means 13a, 13b . . . 13k which indicate the selected velocity in each case. The " harmonic velocity generator " H of Fig. 1 gives ten input speeds, 0, J . . . 9. A stationary shaft 60, Fig. 3, and input shafts 61 ... 69 surround a non-rotating supporting shaft 91, Fig. 2. The input shaft 61 drives through an idle gear train 81 to the shaft 62, in turn driving through an idle train 82 to the next train 63 &c. The ratios between the succeeding trains are 2/1; 3/2; 4/3 . . . Each shaft 61, such as the shaft 65, carries three gears 105a, 105b, 105c. Each gear can be selectively connected to its shaft by an electromagnetic clutch 125a ... , comprising the " velocity selection means." The gears 105a &c. mesh with external teeth on a ring gear 92a. Each ring gear 92 is meshed by planet pinions 94a . . . on carriers 96a .... The planet pinions mesh sun gears 93a .... The sun gear 93a of the first train A is held stationary while the planet carrier 96a is fast with the sun gear 93b of the second train B. Similarly, the carrier 96b of the second train drives the sun gear 93c of the third train C. The output shaft of the gear is comprised by the planet carrier 98c of the third train C. Each of the ten clutches 100a ... 109a associated with each train A &c., is controlled by a ten-pole switch 131, Fig. 4, in a control panel 130. Associated with each switch is a dial 136 showing which of the clutches, and hence which ratio, in each train is selected. Reading the three dials in combination allows the exact ratio imparted to the output shaft 98c to be determined. As a modification, the clutches 125a . . . may be hydraulically or mechanically controlled.