Patent GB-170237-A (GB)
Title: Improvements in and relating to electric switches
IPC: H01H51/12
Filed: 1921-02-16
Abstract: 170,237. Igranic Electric Co., Ltd., (Cutler-Hammer Manufacturing Co.). Feb. 16, 1921. Electromagnetic switches; sparking, preventing; switchboards.-Switches of large currentcarrying capacity are constructed of very narrow dimensions, whereby a number of them may be assembled together in a confined wall space, by employing two independent electromagnets arranged one above the other and acting cumulatively and simultaneously through a linkage mechanism on a contact-operating rod, the central axes of all the parts being located in the same central vertical plane at right-angles to the switch base. In the construction shown in Fig. 1, the superimposed solenoids 7 are mounted within a rectangular magnetic frame secured to a vertical support 51. Within each solenoid a non-magnetic sleeve is secured, and at opposite ends of the respective sleeves are mounted fixed centrally bored pole-pieces 55 co-operating with sliding cores 56 pivotally connected at their front ends by adjusting-pins 62, 63 to two arms of a T-shaped link pivoted at 60, the third arm being pivoted to the switch-operating link 9. The rear end of the upper core 56 is provided with a guide-pin passing through the fixed pole-piece and supported on a roller 64, whereby frictional retardation of the core is avoided. The lower core bears directly upon a roller 65 for the same purpose. When the solenoids are energized to close the switch they move in opposite directions but both produce a counter-clockwise torque on the T-shaped link and consequently a pull in the rod 9. The rod, which is adjustable and provided with insulating sleeves 68, 71, is linked to the switch arm 20 pivoted on the shaft 13 mounted in brackets 15 and secured by bolts 17 readily detachable from the front. This method of mounting enables the switch arm to be removed from the front without lateral movement. The vertical part of the switch arm carries the movable contact 3 cooperating with fixed laminated brush contacts 5 in halves, each independently connected to the fixed contact support 26, 27 by flexible leads 29, 30. The shaft 13 also carries, pivoted upon it, an auxiliary contact arm 4 in spring connection with the main. arm and carrying the sparking- contact 24 for engagement with the fixed sparking- contact 6 located within a magnetic arc-shoot. Contacts 3, 24 are connected to one of the switch terminals 12 by strap conductors 22, 23. The arc-shoot comprises a core 37 energized by inner and outer single convolutions of strap conductor connected between one of the fixed terminals 10 of the switch and the fixed contact support 27, the core having lateral plate polar extensions 36 which, in conjunction with insulating side plates 40, rear plate 41, and top plate 42, enclose the sparking-contacts. When a number of the switches are mounted close together on a panel, Fig. 5, the operating-mechanism or the switch parts of any switch may be readily removed from the front without disturbing neighbouring switches. To provide for alternative hand operation, a cam 76 on a rotatable shaft 79 is brought into engagement with a roller 78 on a lever pivoted at 60 and carrying an adjustable pin 77 which engages the T-shaped operating-link. By suitably shaping the cams, the switches may be closed in any desired order.