Patent GB-820538-A (GB)
Title: Electrical coupling device for industrial use
Inventor: HEALY JOSEPH FRANCIS
IPC: H01R13/20
Filed: 1957-09-19
Abstract: 820,538. Two-part couplings. HUBBELL Inc., H. Sept. 19, 1957, No. 29516/57. Class 38(1). Contact blades 15, 16, are inserted into slots 32, 33, until noses 15<SP>11</SP> and 16<SP>11</SP> clear the corresponding protrusions forming locking recesses 30<SP>1</SP> in cavities 30. During the last part of the movement, pressure pad 19 engages plunger 42 and thereby loads spring 43. The contact blades now engage spring contacts 31, and the cap 10, 11, is rotated relatively to the base 25 until the noses 15<SP>11</SP>, 16<SP>11</SP> are lodged in recesses 301. When the cap is released the plunger 42 locks the two parts of the coupling together. To release the cap from the base, the cap is pressed toward the base against the action of spring 43 until the interlocking parts are clear of each other, and the cap is then rotated until blade portions 151, 16<SP>1</SP>, are registered with slots 32, 33, whereupon the blades can be withdrawn from the slots. In another embodiment, the plunger assembly is replaced by an elastic ring which is retained in base 25, Figs. 7, 8 and 9 (not shown). When the cap is applied to the base, this ring is compressed and serves to lock the cap to the base. The ring also provides a dust and moisture-proof seal between the cap and base. In a further modification, the cap comprises an insulated body having a cavity housing a rubber grommet retaining a two-wired cord. The grommet is pressed into position by a metal plate which is screwed to the cap. In this modification, the cap mounts a plunger of resilient material which has a protruding portion adapted to abut against the base and to be compressed so as to afford interlocking action between the cap and the base, Figs. 10 and 11 (not shown). The cap may comprise a spring- actuated axially slidable earthing-pin the base having an earthing socket for the pin. The pinspring is compressed when the cap and base are locked to each other, Figs. 12 and 13 (not shown). A lateral extension may be provided on both sides of the shank of each contact-blade, and the cavities in the base are so designed that the parts of the coupling may be locked together by rotating the cap in either direction, Figs. 14, 15 and 16 (not shown). In another arrangement of the contact-blades, the edges of the extensions coacting with the cavity wall are sloped downwardly toward the shank of the blade, so that twisting of the cap causes automatic movement towards the release-position. Alternatively, the edges of the lateral extensions may be straight in the circumferential direction, Figs. 17-20 (not shown). Furthermore, the contactblades may be provided with indentations adapted to co-operate with projections in the spring contacts, Figs. 21-23 (not shown). The contact-blades may have extensions which provide a cam-action imparting to the cap a rotary motion towards its release-position when a force above a predetermined value is exerted to separate the cap from the base. For this purpose, the edges of the extensions engageable with the locking-recesses are upwardly slanted towards the shanks of the blades, Figs. 24-26 (not shown).