GB1392573A - Electric plug-and-socket couplings - Google Patents

Abstract

1392573 Two part couplings BODENSEEWERK GERATETECHNIK GmbH 19 Sept 1972 [30 Sept 1971] 43416/72 Heading H2E A plug and socket coupling has main contact pins (18) and contact bushes (24) and also monitoring contact pins (20) and bushes (22) respectively, the monitoring contacts being arranged around the peripheries of the plug and socket, with the monitoring pins being shorter in length than the main pins and/or the monitoring bushes being shorter in length than the main bushes. The monitoring contacts are connected to an e.m.f. and a warning signal so that if the plug and socket are insufficiently mated to connect the shorter monitoring contacts the signal is actuated. In a further embodiment, the monitoring contacts are of two lengths (i.e. pins and/ or bushes of two lengths) to give a differential warning-thus when effecting mating both length monitoring contacts are connected but while in use a limited slackening between the plug and socket is permitted, sufficient to disconnect the shorter monitoring contacts without actuating a warning, further slackening separating the longer monitoring contacts at a point when connection between the main contacts is inadequate to actuate the warning signal. The signal may consist of a lamp which is extinguished when the monitor contacts become disconnected, or a relay or transistor operated lamp or hooter which become energized when the monitoring contacts are disconnected. A plurality of plug and socket couplings may be provided with a common selector switch (52) with the monitoring contacts of the plugs and sockets being connected together in series to an e.m.f., while current is tapped off between adjacent couplings and fed to the switch which has a signal for each coupling.