GB1466451A - Rotary switch - Google Patents

Abstract

1466451 Rotary switch SIEMENS AG 9 May 1974 [9 May 1973] 20652/74 Heading H1N A rotary switch having three terminals has its contacts so arranged that any two of the terminals are connected together with the third isolated, or all three terminals are connected together, or all three terminals are isolated from one another, and an arrangement of apertures are provided in the switch to receive an electrically conductive earthing rod so that one of the terminals may be earthed in one or some switch positions but not in other positions. The fixed contacts 2 of the switch are arranged a multiple of 72 degrees apart in a circle around a rod which carries the moving contact member 1, two adjacent ones of the fixed contacts 24, 25 being interconnected and connected to one terminal AR, two other fixed contacts 27, 28 being independent and connected respectively to the other two terminals R 1 and R 2 , and one contact position 26 adjacent the interconnected two fixed contacts being left without a contact. The moving contact has three contact arms 15, 16, 17 which contact the fixed contacts, as the switch is rotated, to interconnect them in the required combinations. In the three phase switch as shown three similar contact sets are arranged in different planes along a common rotatable shaft 11. This shaft carries a disc 3 having apertures 31, 32 which are alignable in predetermined combinations, as the shaft is rotated, with apertures in a metal earthing plate 4, through which the shaft passes, to allow an earthing rod to be passed or not, according to whether the apertures are aligned or not, through them and through apertures 22 in the fixed contacts to earth them. The switch may be installed in a transformer housing and may be in a dielectric fluid filled container.