GB702232A - Improvements in or relating to methods and apparatus for making branched pipe fittings - Google Patents

Abstract

702,232. Making pipe fittings. IMPERIAL CHEMICAL INDUSTRIES, Ltd. July 30, 1952 [Aug. 1, 1951], No. 18207/51. Addition to 700,855. Classes 83 (2) and 83 (4) A method of forming a branched pipe fitting as described in the parent Specification is modified in that the portion of said blank not in contact with the wall of the main die cavity is supported throughout the-forming operation by a hydraulically-actuated plunger. The operation and apparatus fully described in the parent Specification is modified in that the support member 7 which slides in the branch cavity 8 is actuated by a hydraulic plunger 9 through a connecting rod 10. The plunger operates in a cylinder 11 to which pressure fluid is supplied from a pipe line 12 and one-way valve 13. A relief valve 14 ensures that there is a pressure difference between the fluid pressure to the support member and the pressure exerted by the hydraulic fluid within the tubular blank. In a modification (Fig. 2) the hydraulic fluid for both the forming and the backing-up process is supplied from a common source. A pipe line 16, 17 and 24 delivers pressure fluid to cylinders 18a and 18b to operate pistons 19a and 19b integral with the plungers 20a and 20b respectively. A channel 21 in the plungers 20a supplies the pressure fluid to the interior of the tubular blank from which it passes through a passage 23 in the plunger 20b the outflow being controlled by a pressure relief valve (not shown). The pressure fluid also supplies a cylinder 26 where it actuates the piston 27 of the support member 28 as previously described. To provide the required pressuredifference the effective area of piston 27 is slightly less than that of each of the pistons 19a and 19b. The plungers 20a and 20b may be mechanically actuated.