| 摘要 |
943,004. Automatic speed control. KOLLSMAN INSTRUMENT CORPORATION. March 16, 1960 [April 6,1959], No. 9259/60. Heading G3R. In a constant speed motor system the output shaft 18 of an electric motor 16 is coupled by means of a spiral torque spring 21 to an escapement mechanism which comprises a ratchet 25, an escapement member 26 and a balance wheel 30 and which is supported between plates 28, 29 rotatable about the shaft 18, an edge of the plate 29 bearing on a fixedly mounted pressure-responsive resistance cell 35 connected in circuit with a winding 39 of the motor 16. The motor torque normally presses the plate 29 against the cell 35. An increase in motor speed above the pre-set speed determined by the escapement rate results in a slight angular displacement of the plate assembly 28, 29 whereby less pressure is exerted on the cell 35. In this case the decrease in pressure increases cell resistance whereby the current in winding 39 is reduced so that the speed is correspondingly reduced. Conversely, should the motor output speed decrease,the resistance of cell 35 decreases with increasing pressure from plate 29 and the current in winding 39 increases to maintain the speed at the predetermined rate. In a modification (Figs. 5 and 6, not shown) two output shafts are coupled by gearing to the electric motor and an amplifier is connected in circuit between the pressureresponsive resistance cell and the motor winding.
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