| 摘要 |
<p>The invention provides that a fastening device comprises a block (22) of plastics material of square cross section. It has a threaded bore (40) for the receipt of a bolt (20) which completes the fastening, and additionally, the block (22) has a through slot (26) extending from one end making the block (22) of U-shape so that it has legs (28, 30) and a base (32). This configuration is such that the legs (28, 30) can be sprung together so that they can be pushed into the end of a square sectioned cable ladder tube (12) to be connected at right angles to a cable ladder rail (10), whereupon they will spring apart so that projection on the legs engage in apertures in the tube walls and the block cannot be retracted. To secure the rail (10) to the tube end, the bolt is passed through a hole in the rail (10) and is screwed into the block, which is locked in the tube end. The advantages are pre-insertion of the blocks in the factory and simple assembly of the cable ladder on site, and secure connection joining of the rail (10) and tube ends (12).</p> |
