GB490371A - Improvements in and relating to high-speed planing machines - Google Patents

Abstract

490,371. Hydraulic transmission of power. LANGE, A., (trading as LANGE & GEILEN MASCHINENFABRIK). Feb. 12, 1937, No. 4196. [Class 69 (ii)] [Also in Group XXII] A hydraulic machine tool such as a high-speed planing-machine has a main pump for operating the table and a subsidiary variable delivery pump which may operate the cross feed of the tool and also has its suction pipe connected to the delivery of the main pump, so that it may assist the reversal of the table. The main pump P driven through gearing m from a motor M draws from a reservoir A and delivers through pipe 11 to a valve V. A valve connection 28 leading from the pipe 11 has check valves 29, 291 which prevent direct flow from the line 11 into line 28. The pipe 11 is also connected to the suction side of the auxiliary variable delivery pump 23 which is driven directly by motor M and delivers through pipe 21 to reversing valve R connected by pipes 19, 20 to the ends of valve V. The pump delivery is controlled by tilting the pump casing by means of a cam 24 and lever mechanism 17, 25. The table is operated by a cylinder 1 connected by pipes 12, 13 to the valve V. Dogs D, D<1> on the piston rod 3 act through a lever 30 to shift the reversing valve. The ends of the reversing valve may be connected to a distributer T for lubricating the machine. The stem 5 of the valve V operates a link 27 to rotate the cam 24 and operate the table feed through ratchet mechanism 26, 26a. In operation during the stroke of the main piston to the right the parts are in the positions shown, the pipe 11 connected to pipe 12 through the valve V, and the pump 23 in its minimum delivery position also connected through valve R lines 19 and 28 and check valve 29 to the pipe 12. Exhaust passes through lines 13, 15, 16. Near the end of the stroke, the dog D shifts the valve R so that lines 21 and 20 are connected and valve V is moved to right, liquid from the front of piston 9 being directed through pipe 19 to the lubrication system. Shifting of the valve V directs fluid from pipe 11 to line 13 to return the table and also directs the subsidiary pump output through line 20 and valve 29 to pipe 11. Movement of the valve stem 5 to the right meanwhile causes the cam 24 first to raise the pump 23 to its maximum delivery position and then to restore it to minimum delivery position which is reached when reversal is completed. The variation in the delivery of the subsidiary pump at the end of the stroke causes the table velocity curve, Fig. 2, instead of falling abruptly from v<1> to v<2> to follow the rounded line shown in Fig. 2.