| 摘要 |
<p>A coupling device (10) is used for joining two pipes (12). Each end of the coupling (10) has a pair of abutting grooves designated inner (16) and outer (18), in its inner surface. Each of inner groove (16) and outer groove (18) has at its largest diameter a substantially flat portion (20, 22) located at its innermost end and then tapers in the direction of the coupling end, forming a ramp portion (26, 28). At the junction between the two grooves (16, 18), the diameter of the outermost groove (18) is greater than the diameter of the innermost groove (16), forming a small circumferential ridge (30). An o-ring (32) is initially set in innermost groove (16) and is compressed as the pipe (12) is pushed into the coupling (10). The o-ring (32) is further compressed as it rolls down ramp portion (26) of the inner groove (16) as the pipe (12) is partially retracted from the coupling (10). As the o-ring (32) is pulled past the circumferential ridge (30), it expands into flat portion (22) of the outer groove (18), forming a seal between the pipe (12) and the coupling (10) and providing a positive indication of sealing.</p> |
