Patent ID: 8157470

Claim:
A coupling comprising first and second tubular objects coupled together by a coupling element; each of said objects further comprising: a panel having an inner surface and an outer surface and a stepped hole having an generally circular outer surface opening and generally circular inner surface opening smaller than the outer surface opening to define a ledge surface at the bottom of a recess, the inner surface opening having four equally spaced inwardly protruding substantially triangular tongues, the outer surface opening having four equally spaced inwardly protruding substantially triangular protrusions; the coupling element further comprising: a substantially cylindrical shank defining an axial direction, the shank having a first end, second end and central zone and four equally spaced rotation stop ribs extending outwardly from the shank; a first pair of oppositely arranged substantially arc shaped resilient insert stop members each having a center recess and two side recesses therein, and each member extending to connect a pair of said ribs; a second pair of oppositely arranged substantially arc shaped resilient insert stop members each having three recesses therein and extending to connect a pair of said ribs, the second pair of members being angularly offset from the first pair of members by 90 degrees and axially offset from the first pair of members; a first set of four locking cams extending outwardly from the first end of the shank, two opposite cams of said first set of cams extending from two of said ribs in a clockwise direction, another two opposite cams of said first set of cams extending from another two of said ribs in a counterclockwise direction; a second set of four locking cams extending outwardly from the second end of the shank, two opposite cams of said second set of cams extending from two of said ribs in a clockwise direction, another two opposite cams of said second set of cams extending from another two of said ribs in a counterclockwise direction, each cam of the second set being connected to a cam of the first set by one of said ribs; whereby the first end is insertable into the hole of said first object until the first pair of stop members is received in said first object recess to abut against the first object ledge surface with the center recesses of said first pair of stop members receiving two of said first object protrusions therein; whereby the coupling element is then lockable to said first object by either clockwise or counterclockwise rotation of 22.5 degrees until said two protrusions are relocated respectively within two side recesses of said first pair of stop member side recesses with the cams engaging behind the panel; and whereby the second end is insertable into the hole of said second object and then lockable to said second object in substantially the same manner that the first end is to the first object.