| 摘要 |
<p>A coupling ring (10) for circular ducts (30, 31) is formed of a single piece of sheet metal and has oppositely extending flanges (46, 47) connected together by an annular channel-shaped rib (12) which cooperatively with the flanges (46, 47) defines oppositely opening grooves (20, 22) containing sealant (68, 70). The relative dimensions of the grooves (20, 22) is such that a hydraulic lock is avoided at the time the coupling ring (10) is telescoped onto the ducts (30, 31). Proper sealing can be visually determined by inspection. In a modified embodiment one of the grooves (22') has a larger diameter than the other (20') so that the larger diameter groove (22') may be telescoped over the male end (124) of conventional fittings used in circular sheet metal duct work, while the smaller diameter groove (20') may be connected to the duct (D) itself. Thus, a coupling is provided for connecting ducts (D) to each other as well as to the male ends (124) of duct fittings.</p> |
