Patent GB-465809-A (GB)
Title: Improvements in or relating to hydraulically operated machine tools such as planers, shapers and the like
IPC: B23Q5/26
Filed: 1935-11-18
Abstract: 465,809. Hydraulic shaping-machines &c. ROCKFORD MACHINE TOOL CO. Nov. 18, 1935, No. 20433 /36. Convention date, Aug. 27, 1935. Divided application. [Class 83 (iii)] A. hydraulically-operated machine tool such as a planer or shaper has a tool (or work) carrier reciprocated by one hydraulic motor and a work (or tool) carrier intermittently fed by another hydraulic motor, means being provided to resist forward movement of the reciprocating carrier to assure the operation of the feed movement. In a shaping machine embodiment, the frame 11 has guides for a reciprocating tool ram 13. The work carrier 19 moves transversely on a rail 17 which is vertically adjustable on ways 18 by hydraulic means. The forward part of the table is braced by a telescoping bracket 21 secured by clamping means 23 and the work is secured in a vice 20. The ram may be traversed at any one of three speeds by means of hydraulic motor cylinders 40, 44, Fig. 2, the highest speed being obtained by admitting the discharge from a pump 30 to the head of a small piston 41, the medium speed by admission to the cylinder 44 and the lowest speed by admission to both these cylinders. A constant high-speed return is obtained by admission to the rear of the piston 41. The rail 17 is actuated by cylinders 135, 136 respectively, secured to the rail, the pistons being secured to the frame and drilled axially for the passage of fluid, no flexible connections being used. Rapid traverse of the table in either direction is obtained from a reversible hydraulic motor 27 geared to the feed screw 145 while intermittent table feed is derived from a motor 26 having a cylinder 147 operating a pawl-andratchet wheel on the screw. Reversing bevel gearing 154 is operated from a hand lever to control the direction of feed. A screw 162 limits the stroke of piston 148 to vary the feed. The variable-delivery pump 30 is driven by a motor 31 and delivers through a relief valve 34 to a valve box containing three piston valve elements VM, VR, VS, respectively. The valve VM has three positions, the stop position (as shown) wherein fluid delivered to port 72 is returned to drain 56 ; the rapid traverse position wherein fluid is admitted only to the work setting motors and the " go " position for normal working. VR is a reversing valve directing fluid to the opposite ends of cylinder 40 and to cylinder 44 to control the direction of the ram movement. This valve is shifted by means of fluid controlled by a pilot valve 60 operated automatically by tappet mechanism 62, 63, on the ram coacting with a rod 61. The valve VS controls the three speeds of the working stroke by directing fluid to either or both the cylinders 40, 44. The movement of valve VR is cushioned near the ends of its stroke by means of tapered recesses 108 in the valve coacting with end sockets 107 to trap some of the fluid and force it gradually past a needle valve 109. Valves VT and VF control the operation of the table adjusting and feed motors. The valve VF has four positions controlled by the handle 193. In operation, with the valves positioned as in Fig. 2, the valve VM is moved leftwards to its rapid traverse position, fluid being then supplied to line 195 and if the rail is to be moved the valve VF is moved say to " rail up " position wherein fluid is admitted to line 190 and cylinder 135 while exhaust flows through line 191, passage 203 and line 204. Valve VF is then returned to " stop " and the rail clamped. Similarly for downward rail movement valve VF is moved to admit fluid to cylinder 136 and exhaust it from cylinder 135. The table may now be rapid traversed by shifting valve VF to " up " or " rapid traverse " position. The flow to cylinder 135 is inoperative since the rail is clamped and this fluid passes through line 183 to valve VT which is moved to the right to supply fluid to motor 27 through line 179 and from the motor through cylinder 136 and line 191 to exhaust. If the valve VT is moved to the left the fluid flows round motor 27 in the opposite direction. The ram is now started by moving valve VM to " go " position to admit fluid through line 92 to rear of cylinder 40 to complete the return ram stroke whereupon the tappet mechanism shifts pilot valve 60 to reverse valve VR. Exhaust from cylinders 41 44 flows through lines 128, 129 and passages 130,91. When valve VR is reversed, the flow is through passage 125 to port 116 of valve VS and thence to either or both the cylinders 40, 44 according to the setting of valve VS. Before the forward ram stroke the feed motor 26 is operated. A back pressure valve 94 imparts resistance to the movement of piston 41 so as to ensure that fluid first flows through line 197, valve VF and cylinder 136 to cylinder 147 to operate the feed.