Patent ID: 6921114

Claim:
A coupling assembly comprising; a coupler body having a generally cylindrical shape and an opening at one end, the coupler body having an inner wall with an inner circumference and an outer wall; a conduit having a generally cylindrical shape complementary to the coupler body, the conduit having an inner wall and an outer wall with an outer circumference and an opening at its end, the outer wall of the conduit having dimensions and shape so that it fits snugly inside the inner wall of the coupler body; an abutment extending from the coupler body or the conduit to limit the extent to which the conduit may be extended into the coupler body; a coupler key groove extending along the inner circumference of the inner wall of the coupler body, the coupler key groove being located axially away from the opening in the coupler body; an aperture connecting the coupler key groove with the outer wall of the coupler; a conduit key groove extending along the outer circumference of the outer wall of the conduit, the conduit key groove having a shape that is complementary to the coupler key groove, the conduit key groove being spaced from its end a distance which allows it to align with the coupler key groove when the end of the conduit abuts against the abutment along the inner wall of the coupler body; the coupler key groove and conduit key groove, when they are aligned forming a parallelogram passageway with acute angles; and a locking key which fits therein having a parallelogram cross section with acute angles that is complementary with of the coupler key groove and conduit key groove, each acute angle of the locking key being greater or less than the complementary acute angle of the coupler body key groove so that the acute angles of the locking key tend to engage tightly the coupler key groove and the conduit key groove if tensile forces are applied to separate the coupler, and the locking key has a length so that it may be inserted into the aperture and engage the coupler key groove and the conduit key groove.