GB889383A - Improvements in or relating to coupling devices - Google Patents

Abstract

889,383. Operating single-indication receivers. ELECTRIC & MUSICAL INDUSTRIES Ltd. May 20, 1958 [May 23, 1957], No. 16462/57. Class 118. [Also in Group XXXVI] A coupling part for fluid hose or, as shown, a plug for a cable 3, incorporates a variable impedance which is adapted to provide a remote indication as to whether the part is attached to or detached from its co.operating coupling part. The plug body 15 is adapted to be secured to a co-operating socket 1 by a screw-threaded sleeve 17 enclosing ring-shaped housings 9; 10 carrying respectively an electromagnet 4 and an armature 11 and surrounding the rear end of the plug body. The coil of the electromagnet is connected in an indicator circuit by leads 6, 7 and is wound on an E-shaped core 5. In the disconnected state of the coupling, springs 12, 13 urge the housings together so that the armature 11 bridges the ends of the core 5, the spring 13 being retained in the sleeve 17 by a stop plate 19 and circlip 20. As the coupling parts are connected the end of socket 1 presses the housing 10, and hence the armature 11, away from the core 5 against spring 13 and through the intermediary of an inner sleeve 23. The impedance of coil 4 is thus decreased and an increase of current takes place in the indicator circuit, such increase taking place after the coupling contacts have engaged each other and being employed either to operate a switch controlling the supply to cable 3 or to give an indication that the coupling is made. As the coupling parts are disconnected, the core 5 and armature 11 engage each other and a corresponding decrease in current in the indicator circuit takes place before the coupling contacts can be separated.