| 摘要 |
<p>1483572 Electromagnetic switches AUTOMATIC SWITCH CO 9 Oct 1975 [29 Jan 1975] 41371/75 Heading H1N [Also in Division H2] A switch which when its coil 98 is pulsed transfers a load from a normal supply source to an emergency supply source has phase contact set 16 for connection of the normal supply terminals 22 to the load terminals 26, a phase contact set 17 for connection of the emergency supply terminals 24 to the load terminals 26, and a neutral make before break change-over contact arrangement 28, 31 arranged so that on switching the neutral contacts close first so that both neutral connections are made then the contact set 16 are opened, then the contact set 17 are closed and then the neutral of the normal source is disconnected. The movable contacts 19 of the set 16 are mounted on an insulator plate 51 secured between members 48, 50 which are pivoted at 49 and also have secured between them a second insulating plate 52 on whch the movable contacts 21 of the set 17 are mounted. When the operating coil 98 is pulsed a plunger armature 99 is pulled into the coil and by means of a link 100 and rotates a weight 101 about its pivot 102. The weight 101 has projecting pins ends 106 engaging in a slot 109 in member 50 and in a slot 108 in a similar pivoted member 73 having an arm 75 connected by a lost-motion bar 76 to the neutral contact assembly which has biasing springs 94. The inertia of the weight 101 carries it to the Fig. 14 position the contacts 32, 33 having closed first (Fig. 11, not shown) before contacts 18, 19 open (Fig. 12, not shown), then contacts 20, 21 close (Fig. 13, not shown) before the Fig. 14 position is reached with contacts 29, 30 open.</p> |
