| 摘要 |
920,693. Tube joints. GEORG FISCHER A.G. Jan. 4, 1962 [Jan. 4, 1961], No. 440/62. Class 99(1). A method of producing an assembly consisting of first and second tubes of thermoplastic material joined together and substantially coaxial with one another, comprises the steps of forming a first tube 2 with an end face 3 lying in a plane substantially perpendicular to the axis of the tube, and forming a second tube 5 with an end portion 7 of an internal diameter greater than the general internal diameter 10 of. the tube and approximately equal to the external diameter of the tube 2 and with a shoulder 8 where the internal diameter of the tube 5 increases, the shoulder having an annular face which lies in a plane substantially perpendicular to the axis of the tube 5 and which is formed with an annular recess 11, the face 8 and the recess encircling the axis of the tube 5, melting the outer peripheral surface of an end zone of the tube 2 adjacent the end face 3 and melting the inner peripheral surface of an end zone of the portion 7, and then immediately fitting the tube 2 into the tube 5 until the end face 3 and annular face abut one against the other with the result that any material scraped from the inner peripheral surface by the tube 2 is displaced into the recess. The tubes are heated in a device 1, and molten material 12, 14 forms an external weld seam. In a modification, the stepped down portion 4 of the tube 2 is dispensed with. |
