| 摘要 |
<p>The plates, which are parallel, are provided with threaded sockets (2). The device is comprised of a threaded tube (3) comprising, at one end, a threaded portion (7) intended to be screwed in one of the sockets (2) and, at the other end, an internal tapered surface (4) and an external fine thread (5). Adjacent to the external thread (5) there is provided a hold surface for a wrench (6), and between the threaded portion (7) and that surface (6) there are provided transverse borings (8). A valve box (9) transversely bored may be tightly housed between the first threaded socket (2) and the hold surface (6). A sleeve (10), provided with a hold surface for a wrench (12) has an end intended to be screwed into the second threaded socket (2), whereas its other end is provided with an external tapered surface (13) intended to co-operate tightly with the internal tapered surface (4) of the threaded tube (3), by means of a coupling nut having a fine thread. The nut (14) is retained above the external tapered surface (13) by means of a stop flange (16) kept in a groove (15) located behind that external tapered surface (13). The transverse borings (8) of the threaded tube (3) are located in the middle of the unit made by the tube (3) and the sleeve (10).</p> |
