Patent GB-686442-A (GB)
Title: Improvements in or relating to apparatus for use in cutting of materials while in motion
IPC: B23D45/18
Filed: 1948-08-05
Abstract: 686,442. Rotary saw. UNITED ENGINEERING & FOUNDRY CO. Aug. 5, 1948 [Aug. 14, 1947], No. 20692/48. Class 145 (ii). A flying saw for cutting into predetermined lengths moving objects such as hot rolled pipe, bars, rods and other rolled sections and comprising a reciprocating means for accelerating a saw supporting carriage up to the same speed as and in a direction parallel to said moving material and means for reversing the reciprocating means to return the saw to initial position is characterised in that electrodynamic means, which do not themselves form part of the reciprocating means, are provided for preventing the speed of the carriage from exceeding the speed of the moving material. In the form shown, Figs. 2 and 3, a sliding carriage 12 is reciprocated along a base member 10 by a piston 27 moving in a hydraulic cylinder 26. Pivotally mounted on the carriage 12 is a bell crank 17 carrying a saw 18 and a drive motor 19 at one end and a cam-engaging roller 21 at the other, the saw being urged towards the inoperative position by a spring 23. The roller 21 bears on a tilting cam 16 which comprises a rocking shaft 41 with cam lobe 42 thereon, journalled in bearing 43 on the main frame 10. Mounted on either end of the shaft 41 are cam-knock-down roller 44 and cam-righting roller 45 which are engaged by cam surfaces 46 and 47 on the sliding carriage. A rack 24 secured to the upper edge of the carriage 12 engages a pinion 52 (Fig. 4) which is secured to a pinion shaft 49 having a friction ring 54 threadably mounted at one end. A friction cone 55, forming with the friction ring 54 a friction clutch, is keyed to the shaft of a reduction gear 51 driven by an electric motor 51a, which is controlled by some known means to run at a speed corresponding to the speed of the moving material. In operation, when the moving material strikes a flag switch 37 (Fig. 5), the four-way solenoid controlled valve 31 is opened to admit fluid to the cylinder 26 and thus move the carriage 12 in the direction of the material. Due to its inertia, the friction ring 54 is moved along the threaded portion of the shaft 49 and engages the cone 55, so that if the speed of the carriage tends to exceed that of the moving material (i.e. the motor 51a), the motor acts as a dynamic brake. As the carriage 12 moves forward, the roller 21 moves along the cam lobe 42 and the saw is moved through the work and back. When the end of the stroke is reached, the cam-knock-down roller 44 is engaged by cam surface 46 to cause the cam to be tilted and a projection 39 trips a flag switch 38 to cause the fluid to be admitted to the other end of the cylinder 26 and so reverse the carriage. At the end of the return stroke, the cam 16 is righted by cam surface 47 contacting the cam-righting roller 45. The Specification as open to inspection under Sect. 91, comprises also a flying saw similar to that described above but without the electrodynamic speed-synchronising means, the fluid to the cylinder being supplied from a variable delivery pump. The delivery of the pump is automatically varied by some means, not specified, so that the speed of the saw is synchronised with that of the material. This subject-matter does not appear in the Specification as accepted.