Patent GB-190508927-A (GB)
Title: Improvements in Electric Switch Apparatus.
Inventor: BERRY ARTHUR FRANCIS
Filed: 1905-04-27
Granted: 1906-03-29
Abstract: 8927. Berry, A. F. April 27. Switches to control several circuits at once comprise two fixed resilient contacts and two movable contacts attached to a rod which is moved by the armatures of a doubly-wound electro-magnet ; one movable contact is mechanically connected to the rod through a system of levers, whereby this contact is made to move through a greater distance than the other. Reference is made to Specifications No. 25,149, A.D. 1902, and No. 2096, A.D. 1904. Movable within the hollow electro-magnet c provided with two windings d, e is a brass rod a, upon which are mounted the two disk armatures g, h adapted to fit round the ends of the electromagnet. To the lower end of the rod is attached by nuts and a screw for adjustment the contact r formed of bent strips of copper preferably of successively increasing thickness, contacting with the fixed contact s, t. The upper switch mechanism comprises an insulating-block v fixed to a metal plate z, provided with tubular lugs which slide vertically on guide-pins 2 attached to the upper armature plate g. Upon the top of the block v is secured the movable contact 5, which fits within the -shaped copper contacts 7, 8, laminated to give resilience. To the upper end of the rod a, between the fixed bracket 4 and the plate z, are attached links 12 connected by antifriction rollers 16, bearing on the bracket 4, to other links 13 which are attached to the webs upon the plate z. When the carrier rod is moved downwards, to open the lower switch, owing to the excitation of the winding d, the links 12 force the lower ends of the links 13 outwardly, causing the plate z to descend, and in consequence open the upper switch, the lower contact r moving through a greater distance than the upper contact 5. If the winding e is now supplied with current, the upper and lower contacts will again be caused to close, the disposition of the links slightly beyond their dead centres being such that, under the action of the laminated contacts 7, 8, the switch is locked in position. The pressure of the upper contacts may be made to balance that of the lower contacts by adjusting the lower contacts along the rod. The windings e, d are controlled by a hand-operated switch with a three-armed lever 18 moving over fixed contacts 21, 22 connected to one end of the windings d, e, and also over the contact 23 connected to one of the poles of the current source. The lever 18 is connected by a pin 24, engaging in a slot 25, with a lever 26 attached to an insulating-piece which connects the upper and lower portions of the rod a. When the rod a rises, the lever 18 is moved to break the circuits through the winding at that time energized, and to close the circuit through the other winding ready to be completed by a relay at the next reverse operation. In a modified arrangement, Fig. 3, the lower contact consists of a metal bar with upwardly-extending wedge ends arranged to enter between spring contacts. In addition, the armature g carries a pair of inclined planes adapted to force the rollers 16 upwards, and the rod a carries a pair of rollers adapted to force the rollers 16 outwards, while the upper ends of the links 12 are connected to the upper ends 11 of the rod a by pin-and-slot connexions 30.