| 摘要 |
1,214,433. Electrical control systems. RUTI MACHINERY WORKS Ltd. Feb. 14, 1969 [Feb. 16, 1968], No. 8277/69. Heading G1N. [Also in Division H3] In the monitoring of the movement of the shuttle of a weaving loom, two signals, whose time spacing is dependant upon the speed of the shuttle, are generated during movement of the shuttle, the signals actuating a device to perform an operation the rate of which is variable, e.g. the charging of a capacitor, and the loom being stopped or an indication being provided when the shuttle speed is incorrect. Two spaced magnets on the shuttle actuate a coil 19 to produce two signals 20 whose time spacing is dependant upon the speed of the shuttle. The signals are applied to a bi-stable circuit, the first signal rendering a transistor 25 conductive and a transistor 26 non-conductive. Thus a capacitor 41 is charged via resistor 40, a fraction of the charging energy being applied to a capacitor 46. The second signal renders 25 non-conductive and 26 conductive. Thus capacitor 41 discharges. During the next cycle, the rate of charging of 41 is quicker since capacitor 46, which does not discharge, does not extract so much charging energy. This operation continues until 46 is fully charged and thus the rate of charging of 41 is constant. The rate of charging of 41 serves as a comparison value for monitoring the time spacing between the signals and thus the speed of the shuttle. The rate of charging of 41 is variable by resistor 40, although 41 itself may be variable, and its value is also determined by the value of components 45, 46. Should the shuttle speed be too slow, 41 charges for a longer period and reaches a threshold which fires a transistor 47 and thus energizes a magnet 53 to initiate a shut-down operation. Alternatively, the value of resistor 40 is continuously varied so that the capacitor 41 reaches the threshold value and the transistor 47 is fired to light a lamp 52. The resistor 40 is thereafter again increased slightly in value and a switch 51 is charged to the magnet 53. The resistor 40 may be provided with a scale. In alternative embodiments two coils and one magnet may be used or the coil(s) may be replaced by capacitance(s). The capacitor 41 may be replaced by a step-by-step switch which supplies a signal at each complete revolution and in which the number of steps and/or the speed of operation may be varied. The capacitor 41 may also be replaced by a regulatable mechanical device. |
