Patent GB-191405431-A (GB)
Title: Improvements in Electrical Switches.
Inventor: HORTON BRYSON DEXTER
IPC: H01H21/42
Filed: 1914-03-03
Granted: 1915-02-18
Abstract: 5431. Horton, B. D. March 3. Switches, quick-action.-In a quick make-andbreak ironclad electric switch of the kind in which the moving contacts 8, Fig. 3, of the switch are carried by a bridge-piece 9 mounted to reciprocate on a pair of parallel guide-rods 11 carried by the base portion 1 of the casing, the bridge-piece is resiliently attached to the outer ends of a pair of arms 25 carried by a rock-shaft 23 adapted to be rotated by a handle 24, Fig. 1, outside the casing and the quick action is obtained by a pair of helical springs 17 mounted on a pair of telescopic rods 18 and adapted to be put under compression between fixed abutments on the corresponding guide rods and an abutment 21 carried by the bridge-piece. In action the springs are compressed until the dead centre, that is the alined position, of the spring is reached in which position the moving contacts 8, which are connected by a fuse, are just about to enter or to leave the fixed contacts 6, and continued movement of the operating handle causes the springs to expand and open or close the switch with a quick action. The quick make action is augmented by the resilient connexion of the arms 25 to the saddle-shaped member 28, Fig. 7, secured to the bridge-piece 9, the arms 25 being jointed to the rods 29 which. pass through the member 28 and are provided with cotter pins 30 at their lower ends. Springs 31 are secured to the upper ends of the rods and the lower ends of the springs bear upon the member 28. In opening the switch, the movement of the arms 25 is transmitted to the bridge member 9 by the pins 30, but in closing the switch the springs 31 are first compressed and, subsequently, the bridge member carried down until beyond the dead centre position of the springs 17, whereupon the springs 31 expand to augment the action of the springs 17. Cases and covers; switch mechanism, interlocking with lids.-The cover is in two parts, one part 2 fixed to the base portion 1 and provided with holes 3 to admit the leads, and the other part 4 hinged at 5 and provided with a hooked extension 33, Fig. 3, which in the closed position of the switch is engaged by a pin 34 on one of the arms 25, thus preventing the raising of the cover until the switch has been put into the open position. To maintain the switch in the open position while the cover is open, a trigger 35, pivoted at 36 and acted on by a spring 38, is provided with a hook 37 which when the lid is opened is released from the pin 41 upon the extension 33 and engages below the pin 34. If it is desired to close the switch while the lid is still open, the trigger can be moved by hand, but when the switch is closed under these circumstances the lid cannot be closed because of the engagement of the extension 33 with the pin 34 just prior to closing, and, consequently, the switch must first be brought to the open position. Handles.-A bushing 48, Fig. 6, is mounted on the side of the casing to provide an increased bearing-surface for the rock-shaft 23 which is provided with a rectangular end, located within a socket portion of the bushing, and engaged by a detachable operating-handle provided with a socket 52 fitting into the bushing and over the rectangular end of the rock-shaft. The end of the rock-shaft may be of semicircular form and the handle similarly formed, in which case the flat part is so arranged that when the handle is inserted it will register with either the on ' or ' off ' indices on the casing according to the condition of the switch. Switches, locking. - A padlock inserted through perforated extensions 42, 43, Fig. 1, on the casing and on the handle prevents unauthorized operation of the switch.