| 摘要 |
760,426. Seaming non-metallic sheet material. UNI-TUBO SOC. ANON. April 30,1954 [May 1, 1953], No. 12610/54. Class 42 (1). A machine for closing the ends of flexible tubes of thermoplastic material comprises jaws for gripping and flattening a tube adjacent the end thereof, means for heating the layers of material projecting beyond the jaws to weld them together and further means for compressing and cooling the weld. As shown, a tube 17 is flattened between a fixed jaw 4 and a movable jaw 5 which is carried by bolts 7 slidable in the fixed jaw and connected to a cross-member 8 which is coupled by a spring 10 and bolt 11 to a casing 9 slidable on a spigot 14 and acted on by a spring 64. The casing is grooved for the reception of the arms of an operating fork 15 carried by a transverse spindle 16. An adjustable, perforated burner pipe 19 arranged to direct flame jets 21 on to the projecting portion of the flattened end of the tube, is supplied with gas through pipes 22, 23 controlled by a spring- loaded valve 27 actuated by a lever 31, a pilot jet 33 being supplied through a by-pass 34. Further jaws 36, 37, Fig. 4, formed with recesses 49 for the reception of the bead formed on the end of the tube, are pivoted on a spindle 40 carried by arms 39 secured to the spindle 16 and are normally held open by a spring 46. The apindte is movable axially by a lever 53 and carries a peg 51 which engages tapered recesses in the jaws to effect closing movement thereof. When the arms 39 are swung downwardly by the operator, the fork 15 closes the jaws 4, 5 and the lever 31 is then operated to open the valve 27 by a cam 57 on a spring-loaded catch 55 pivoted to an arm 56 on the spindle 16. During further downward movement to bring the jaws 36, 37 into their operative position, the cam rides over the follower 58 to allow the valve to close and cut off the supply to the jets 21. The lever 53 is then operated to close the jaws. On the subsequent retraction of the arms, the spring-loading of the catch allows the cam to ride over the follower without opening the valve. The jaws are formed with passages 61 for the circulation of cooling water. The jets 21 may be replaced by jets of hot gas or air. |
