| 摘要 |
<p>PURPOSE:To make adjusting easily the pressure of the pressure adjusting spring possible, by setting a screw shaft projected on a vice and a knob on a projected end of the screw shaft to fit it to the end surface of the pressure shaft, by setting a spring holder and a pressure adjusting spring and by setting a pressure scale on the outer surface of the spring holder. CONSTITUTION:When resin pipes of large diameters a, b are welded, the switch 29 does not work even if a thimble contacts it. After the switch 30 enlarges the compressed amt. of the pressure adjusting spring 22 by means of a pressure shaft 18, the shaft 18 contacts with a press button 30 a. Namely, the pressure changes depending upon the difference in the diameters of the pipes a, b. The stretched/compressed amt. of the pressure adjusting spring 22 can be easily adjusted and the adjusted state can be easily kept. The adjustment increases the spring pressure in accordance with the initial torque the long resin pipe a has. Namely, the pressure shaft is adjusted in such a manner that the extreme point should coincide with the right end of the pressure scale M of the spring holder 21 and the pressure adjustment is thereby given when no initial torque of the pipe a exists. The end surface of a pressing screw 46 whose outer side is extended contacts under pressure with the part where the spring holder 21 fits to the screw shaft 15 to prevent unnecessary rotation.</p> |
