GB152438A - Improvements in electrical low tension oil switches - Google Patents

Abstract

152,438. Norton, R. T. July 17, 1919. Controllers; actuating.-A two-way switch for starting motors is provided with locking-mechanism, which prevents it being moved into the running position until it has first been moved to the starting position, comprising primary and secondary detents engaging a shoulder on the switch operating arm and a catch which locks the operating handle in both the " off " and running positions and is released by the movement of the secondary detent. As shown in Fig. 1 applied to an oil switch having the contacts mounted on a spider-drum or drums secured on the spindle f by angle-plates g<2>, Fig. 5, the drum is rotated by the engagement of the forked lever d on the handle shaft b with a crank e' on the drum shaft which is maintained in the central " off " position by the springs w, x. The switch is latched in the " off " and running positions by the engagement of a pin r on the handle lever a<1> with one of the notches in the spring-controlled notched latch n pivoted at p. The operating lever is formed with a nose d<1> and a shoulder d<2> which is normally engaged by a detent h pivoted on the casing and serving to prevent upwards movement of the handle which, when the latch n has been moved back by hand, would move the switch directly into the running position. Downwards movement is, however, possible and this moves the drum into the starting position; at the same time the nose d<1> lifts the detent h, which is caught and held in the raised position by the secondary detent k which is connected to the first by the springs t and is released to engage the first detent by the removal of the shoulder d<2>. An arm k<1> on the secondary detent releases the latch n by pressing upon an arm m of the latch. The handle lever may now be reversed; in this movement the arm k<1> moves away from the arm m of the latch which again engages the pin r and locks the switch in the running position. The latch has an extension n<1> so that it can be controlled by a low-voltage or other tripping current. Alternatively, the catch may be released by hand.