Plug-in coupling

Claim 1

A multiple-passage plug-in coupling for releasably connecting hose or pipe ends, the coupling comprising: a first coupling part, longitudinally-extending parallel nipples on that part, a second coupling part, longitudinally extending parallel sleeves in the second coupling part to receive the said nipples when the said two coupling parts are plugged together by a simple, axial, non-rotary movement, two guide projections disposed non-centrally on one of said coupling parts, two corresponding guide recesses to receive the said two projections disposed non-centrally and at opposite locations in the other one of said coupling parts, channels in the said projections, further channels in the said other coupling part, said channels in the guide projections being in alignment with said channels in the said other coupling part when said first and second coupling parts are plugged in together, a U-shaped locking member slidably disposed in said channels of said other coupling part and being slidable into and beyond said channels in the said two projections whereby to lock said first and second coupling parts together, shoulders forming interruptions in said channels of said other coupling part adjacent said two guide recesses, and outwardly-directed latch surfaces at the free ends of the U-shaped locking member adapted to engage said shoulders and thereby prevent said locking member from becoming entirely detached from said other coupling part while allowing said U-shaped locking member to be movable to a position where the latter is clear of said channels in the said projections to allow said first and second coupling parts to be unplugged from each other.