Patent GB-371595-A (GB)
Title: Improvements in and relating to switches for selectively controlling electrical circuits
IPC: B60R16/00
Filed: 1931-04-16
Abstract: 371,595. Road - traffic signals on vehicles. THIMBLETHORPE, W. S., 42, Jermyn Street, Piccadilly, London. April 16, 1931, No. 11288. [Class 118 (ii).] In road-vehicle signalling apparatus as described in Specification 371,453, the controlling switch comprises a handle 22 on a spindle 25 which handle is first rotated to a selected position, then withdrawn into the position shown in Fig. 9, and then pushed or allowed to return back thereby momentarily closing a warning circuit and then closing the selected circuit. In the example shown, a retractive spring 32 acts on the spindle 25 to return it, and the return of the spindle is delayed by a dashpot device 24, 26 and the slow return movement is used to cause an intermittent opening and closing of the selected circuit. The spindle 25 is square and carries frictionally on it a disc-shaped insulating member 42 that has mounted on it a sectorshaped contact 41 and another contact 34 that extends round the edge of the disc and across one face of it. The frictional mounting consists of a spring-pressed plunger 35 bearing on the spindle 25. A series of seven contacts 46..52 is arranged in the casing round the spindle, one contact 46 being connected to a battery and the other six contacts being connected to lamps. These contacts are adapted to be selectively engaged by the sector contact 41 according to the angular position of the latter the precise angular position being determined by projections on a plate 30 on the spindle engaging depressions in a plate 28. A projection on the member 42 is also adapted to engage two of these six contacts which are specially shaped and depress them out of engagement with the contact 41 when this is engaging contacts on either side. A series of three contacts 54, 55, 56, is also arranged on the other side of the disc member, one of these contacts 55 being connected by a spring 53 with the contact 46 and thus to the batterv and the other two contacts being connected by similar springs with the contacts 47, 52 and thus to two yellow lamps. With the switch in the position of Fig. 9, a warning circuit is closed from the battery to the contact 55 and thence through the contact 34 to the other two contacts 54, 56 and the yellow lamps. When the handle is released, the spring 32 moves the spindle upwards carrying with it the disc member 42 and causing the contact 34 to leave the contacts 54, 56 thus breaking the warning circuit and the contact 41 to engage the selected two or three contacts 46 .. 52. The current now passes from the battery to the contact 55 which still engages the contact 34, being differently shaped from the contacts 54, 56, and from the contact 34 through an interrupter switch in the disc 42 to the contact 41 and the selected contacts 46 .. 52 and the lamps to which they are connected. The interrupter switch, which causes an intermittent flickering of the lamps, comprises a roller 44 which frictionally engages the spindle 25 and is rotated thereby during the retarded movement of the spindle. The roller which is electricallv connected to the contact 34 carries two series of pins 44a which intermittently engage spring-pressed balls 45 electricallv connected to the contact 41. At the end of the travel of the spindle the handle 22 engages a pushbutton 37 which in turn engages the contact 55 and tilts this out of engagement with the contact 34 so that the circuit to the lamps is broken.