GB743417A - Improvements in or relating to the manufacture of seamless metal tubes - Google Patents

Abstract

743,417. Rolling-mandrel carriages. WELLMAN SMITH OWEN ENGINEERING CORPORATION, Ltd. Feb. 12, 1954 [Feb. 27, 1953], No. 5608/53. Class 83 (4). In a pilger rolling mill the shock transmitted to the carriage 11 by the cushioning means at the end of the return stroke, is taken up by hydraulic piston and cylinder apparatus 17, 18 from which hydraulic fluid is released in a predetermined quantity per operation so that the feed rate is precisely controlled. The cylinders 17 which are also used for stripping the work from the mandrel 33. are mounted on the base 10 and the pistons 18 are connected to a cross-head 19 on the carriage 11. The release of fluid from the cylinders 17 during the forward feeding steps of carriage under actuation by a hydraulic cylinder 13 is controlled by a pair of opposed cylinders 42, 43 which are alternately connected after each operation by an automatically actuated change-over valve 47, a stop valve 48 providing a restricted orifice for the flow. The common piston 52 of the cylinders 42, 43 is limited in its movement between stops 54, 55 and adjustment is provided by packing 61. The cylinders 42, 43 are mounted on slides 59, 60, and are yieldingly located against stops 57 by springs 58 or equivalent hydraulic or pneumatic cylinders so that on the transmission of the shock resulting from the arrest of the work by the cushioning means additional fluid passing to the cylinders 42, 43 in compressing the springs 58 is restored to the cylinders 17 to maintain the constant rate of feed. In stripping the finished work from the mandrel 33 high pressure fluid is supplied to the cylinder 17 through a pipe 63 and valve 49.