| 摘要 |
<p>The body has two saddle arms (6, 10) whose ends are firmly connected with associated rings (5, 9). Threaded connecting pieces are positioned together so that saddle arm of the upper threaded connecting piece (1) is accommodated in the opening of the large ring (11) of the lower thread connecting piece (2). The saddle arm of the lower threaded connecting piece is accommodated in the opening of large ring of upper threaded connecting piece.</p> |
