Patent GB-522338-A (GB)
Title: Improvements relating to control mechanisms for metal cutting and other machine tools
IPC: B23Q5/54
Filed: 1939-01-07
Abstract: 522,338. Feeding grinding-machine slides. WEBSTER & BENNETT, Ltd., and BENNETT, D. W. Jan. 7, 1939, No. 614. [Class 60] [Also in Group XXII] In a device for controlling a machine tool such as a boring and turning mill or a grinding- machine having work or tool slides movable in perpendicular directions a manual control lever actuates the various directional controls by means of pivotal movements in at least two planes at right angles to each other and has also an axial movement for effecting speed changes in the slide movements. In one form a lever a pivoted at b between a fixed abutment g and a spring pressed abutment h may be moved through a gate c having either two slots at right angles or four slots at 45 degrees. Theinnerendof the lever is connected at n to a member k on a cam shaft m. Movement of lever a in a horizontal plane (plane of paper) causes the shaft m to move axially whereupon cams r, p actuate plungers s to open valves t forming part of hydraulic mechanism controlling horizontal tool movements. Similarly movement of lever a in a vertical plane rotates the shaft m and causes a cam q to actuate the valves controlling the vertical tool movements. If the lever is moved at an angle to the horizontal both vertical and horizontal tool movements may be operative simultaneously. To control the rate of feed the lever is moved axially, thus forcing back the member h and causing a plunger u to operate a switch or valve 13 to change to a high speed either through variable gearing or by starting up another motor. Spring stops w prevent the lever a from being moved axially to change to the high speed unless it is in its neutral position but when the high speed is operative the stop collar x on the lever is between the stops wand the lever may be shifted to engage the lower speed without first returning to neutral. In a modification, Fig. 2, the control lever is in two parts a, a<SP>1</SP> relative axial movement between the parts being limited by pin-and-slot 2, 3. The part a<SP>1</SP> is pivoted on trunnions 8 to a forked part 5 which is itself carried on a trunnion 7 having an axis at right angles to the trunnions 8. The part a<SP>1</SP> is secured to a member 9 carrying cams p ... p<SP>2</SP> which actuate the control plungers s ... s<SP>2</SP>. Thus movement of the handle in a horizontal plane moves the part a<SP>1</SP> about the pivots 8 and controls the horizontal tool movements while movement in a vertical plane rocks the part 5 around trunnion 7 and controls the vertical tool movements. Axial movement of the lever portion a causes its tapered end to actuate a plunger u to effect the speed change. Overlapping spring blades 14 coact with a stop collar x to prevent axial movement unless the lever a is in neutral but when the high speed is in operation the stop collar is between the springs and the lever may be returned to low speed position without first returning to neutral. The manual lever may be replaced by a foot lever. The controls operated by the lever may be valves, switches, clutches, or other mechanisms.