GB148655A - Improvements in controlling means for controlling a series of electric motors - Google Patents

Abstract

148,655. Warburton, F. G. May 12, 1919. Systems depending on the use of two or more motors. - In control mechanism of the type described in Specification 22897/14 for motors driving paper - making machines &c., the control is effected by the linear displacement of a member caused by the variation of the speed ratios between the master-control shaft and the individual motors. In the form shown in Figs. 1 and 2, the mastercontrol shaft a runs along the length of the papermaking machine and is provided with a feathered worm b for each motor to be controlled. Each motor c drives a shaft d through change-speed gear such as cone pulleys, or friction disks, and this shaft carries the worm-wheel h engaging the appropriate worm b. As long as the master shaft a and the motor c run at the designed speed ratio, the worm gearing works without any axial movement of the worm, but if this ratio is disturbed the worm moves axially and moves the rack j meshing with a pinion k which rotates the motor brushes to restore the speed ratio. The axial movement of the worm may actuate a shunt regu-. lator, series diverter, or rotor resistance switch. In a modification, the motor c drives one shaft of a differential gear, while the casing is driven from the control shaft a. When the speed ratio varies, a pinion on the end of the differential shaft rotates the motor brushes. In another modification the differential shaft winds up a rope to vary the positions of the plates in a liquid resistance.