GB830084A - Improvements in or relating to electrical contact-making devices - Google Patents

Abstract

830,084. Jacks and plugs. POSTMASTER GENERAL. June 26, 1957 [July 24, 1956], No. 22899/56. Class 40 (4). To facilitate maintenance spring terminals are detachably mounted within an insulating sleeve. In the jack strip seen in Figs. 2 and 3 a block of insulator is bored from edge to edge to form adjacent socket housings each with a narrow mouth portion 3 and a wider inner region which is longitudinally grooved at three radial positions 7. The spring terminals are shown in Figs. 5 and 6 and each comprise a longitudinal U-sectioned rib 9 with projecting contact lugs near one end bent so as to form inwardly-directed elbows, between portions 10 and 11, which make resilient contact with a plug surface. Contact is also made with the rounded end portions 12. The U-sectioned rib of a terminal lies in one of the grooves 7 of the housing and in the case of that terminal providing the contacts nearest the mouth 3, the rib extends through the front surface of the housing where it provides an exposed surface for click testing. Behind the contact lugs of this terminal an insulating separator 14 is placed before insertion of the terminal providing the second set of contact lugs which are similarly spaced by an insulator 15 from the third and last set of contact lugs. To hold the terminals in place against the abutment provided by the mouth 3 of the socket housing a pressure block 16 bears against the last set of contact lugs under the action of a spring 20 secured to the block 16 and to a block 21 connected into the rear end of the plug housing by means of a bayonet fastening. An alternative construction is shown in Figs. 7 and 10 and uses terminals as shown in Figs. 11 and 12, each comprising a connecting-strip 42 and inturned contact lugs 43. The inturned contact lugs 43 project through apertures such as 44 in an hexagonally cross-sectioned plug sleeve of insulating material, the connecting strip 42 lying outside the hexagon and along its length. The open mouth of the sleeve is lined with metal and has a connecting-strip 41 which is connected to the sleeve contacts to permit a click test. The rear end of the plug sleeve contains a threaded insert 37 whereby the sleeve may be secured with its associated terminals in a bore of a jack strip housing as shown in Fig. 7. The bores in the housing are blind except for apertures to pass the connecting strips and a bolt 33 to engage the threaded insert 37.