Load indicating metering devices for motor driven loads
First Claim
1. A monitored power transmission system, comprising in combination, a motor with a characteristic that speed varies with load having a movable shaft, a motor driven movable device providing a variable load coupled to said motor shaft by power transmission means for movement at a speed determined by said motor, an analog metering device having means producing in response to said motor speed an analog speed range visible on an output meter scale, electronic calibration means in said metering device conforming the portion of the motor speed range that corresponds to peak motor load conditions to a monitored parameter related to and different from the motor speed and producing an electrical output of that parameter, and means in said metering device responsive to said electrical output of that parameter operating said metering device for displaying on said visually readable scale said monitored parameter in calibrated units displaying the variable load condition imposed on said motor.
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Accused Products
Abstract
Power transmission systems having a movable member presenting variable load conditions on a motor connected thereto by means of a power transmission device are monitored by load sensing means. Sensed signals are processed to produce visual display conditions and corresponding control signals for selected motor loading parameters. The system accurately and simply measures and displays load conditions in flexible calibrated scale factor and digital form reducing possibilities of human readout error. No wiring or mechanical connections are necessary in the power train and reliable, sensitive output signals are produced with simple and miniature retrofittable electronic processing circuits. Alarm signals exceeding predetermined threshold load levels are stored digitally in a flip-flop circuit or equivalent relay for memory and control of external devices. Thus, the display form includes calibrated analog metering scale and digital memory type data processing devices permitting monitoring to correct system operating conditions when the motor is overloaded. Thus, the power transmission system can operate with motor ratings substantially equal to or less than expected full load conditions to substantially reduce initial equipment cost and operating expenses over equipment life.
18 Citations
16 Claims
- 1. A monitored power transmission system, comprising in combination, a motor with a characteristic that speed varies with load having a movable shaft, a motor driven movable device providing a variable load coupled to said motor shaft by power transmission means for movement at a speed determined by said motor, an analog metering device having means producing in response to said motor speed an analog speed range visible on an output meter scale, electronic calibration means in said metering device conforming the portion of the motor speed range that corresponds to peak motor load conditions to a monitored parameter related to and different from the motor speed and producing an electrical output of that parameter, and means in said metering device responsive to said electrical output of that parameter operating said metering device for displaying on said visually readable scale said monitored parameter in calibrated units displaying the variable load condition imposed on said motor.
Specification