| 摘要 |
710,856. Joining rods. BRITISH INSULATED CALLENDER'S CABLES, Ltd. Oct. 29, 1951 [Oct. 30, 1950], No. 26466/50. Class 99 (1). [Also in Groups VIII, IX and XXV] An apparatus for butt welding together two pieces of thermoplastic rod comprises a pair of clamps for gripping the pieces, at least one of the clamps being movable endwise to and from the other clamp towards which it is resiliently urged, releasable means for holding the clamps apart, and a heating blade which can be moved into an operative position between the clamps to heat the neighbouring ends of the rods projecting from the ends of the clamps and can be withdrawn to allow the clamps, after release of the holding means, to move towards one another under the influence of the loading force to press the hot ends of the pieces together. The apparatus comprises a framework, 1, 2, 3 to which one clamp 6 is attached by screws 7. A pair of rods 20 is held between the clamp 6 and a bridge piece 18 and a second clamp 22 is slidable thereon and urged towards the first clamp 6 by a pair of springs 28, the force in which can be adjusted by varying the position of collars 29. Each clamp comprises a pair of jaws 9, 10 located in position by dowels and held together by pivoted spring clips 16. The jaws 9 and 10 are provided with corresponding grooves 13 and 14 with which to grip the pieces of rod to be joined. A cylindrical extension 24 upon the clamp 22 is located within a corresponding aperture 27 in the clamp 6 when the clamps are closed together. A bridge piece 31 is slidable upon a pair of struts 32 and carries a rod 30, the upper end of which is wedge-shaped. A pivoted lever 35 co-operates with the bridge piece 31 so that by depressing a handle 40 the bridge piece is raised and the wedge-shaped portion of the rod 30 cooperates with a chamfer 34 on the clamp 22 to separate, and hold apart, the clamps as shown in Fig. 4. The lever 35 is returned to its original position by a spring 41 and the rod 30 held by the pressure between the clamps 6 and 22. The rod 30 is recessed at 46 and 47 to provide a setting up guide for the pieces of rod. An arm 43 is pivoted to the frame 1 and comprises a heating blade 44 and a projection 45. The blade 44 may be heated by a gas flame or electrical means, and when the arm is rotated to the position shown in broken lines, Fig. 2, between the separated clamps, the projection 45 holds the clamps apart and being slightly thicker than the rod 30, allows the latter to fall to its lower position, and the blade 44 heats the ends of the rods. When the arm 43 is again raised, the clamps are urged into contact by the springs 28 and the softened ends of the rods become welded together. |
