Patent GB-604221-A (GB)
Title: Improvements in or relating to feeding systems for metal cutting machine tools
IPC: B23G1/02
Filed: 1945-07-25
Abstract: 604,221. Lathes. AKTIEBOLAGETBOLINDER-MUNKTELL. July 25,1945, No. 19063. Convention date, Aug. 8, 1944. [Class 83 (iii)] In a lathe having a rotary hydraulic feed motor mounted on the lathe slide and connected through reduction gearing to a rack on the lathe bed, a motor control valve on the slide is connected to flexible wires wound on a roller of a feeding device mounted on the bed of the lathe, the roller being rotated from the lathe spindle through a chain of gears. The feed controlling device carries a shaft 22, Fig. 1, connected to a shaft 18 driven from the lathe spindle through change gears and the shaft 22 carries an axially displaceable worm 24 which may be fixed in or out of engagement with a worm-wheel 32 by means of a pin screw 26 entering one or other of two holes such as 30. The worm-wheel is carried on a shaft 34 also carrying a roller 36 to which two wires 68 are fixed by screws 66 so that they are wound on or off the roller as it rotates. For screw cutting, the roller drive is direct from the shaft 22 through the worm 24 and worm-wheel 32, but, for ordinary feeding, a variable drive is provided by a spring-loaded friction disc 38 bearing on a roller 46 splined to a shaft 48 and axially displaceable by a fork 58 operated by a rotatable nut 62; this drive rotates the worm-wheel 32 through a worm 50 displaceable on the shaft 48. Two levers 106, Fig. 7, on a pump housing attached to the lathe slide are connected to the wires 68 by a connector 94 and a flexible band 92 passing round a roller 96 on the levers. The levers are connected to a lug 100 on the pump housing by a band 98 also passing round the roller and to a valve slide 116 in a valve housing 102 by a flexible band on a roller 110. The valve is supplied from a pump, not shown, by a connection at 122 and exhausts at 162, and comprises a number of discs attached to the hollow slide 116, which is loaded by a spring 118, and discs of the same thickness attached to the housing. When the valve slide is moved to the left, liquid flows along an axial groove 124 in the outer discs, through radial holes 128, in every fourth outer disc, round annular recesses 130, 134 in the discs, through radial holes 138 at the top of every fourth outer disc and along an axial groove 140 and a passage 142 to a hydraulic motor 82, Fig. 6, which drives the lathe slide to the left through a gear  72 engaging a rack 70 ; the exhaust fluid from the motor is returned through an axial groove 146 and holes 158 to the interior of the slide and to the exhaust connection 162. When the valve slide is moved to the right, the fluid flow is reversed, driving the lathe slide to the right, and in the intermediate position of the valve leakage to right and left of the annular recesses 130 maintains equal pressure on both sides of the pump, which is then stationary. In operation, with the lathe slide moving to the right, the wires 68 are wound on to the roller, which may have undulations to correct faults in the worm-wheel, and if the lathe slide lags behind, the valve slide is moved to the right and speeds up the motor to increase the speed of the slide, and vice versa.