Patent GB-1000562-A (GB)
IPC: F16H61/02
Abstract: 1,000,562. Change-speed gearing and control; clutch control; epicyclic gearing. B. ELLIOTT (MACHINERY) Ltd. Feb. 7, 1964 [Feb. 15, 1963], No. 6222/63. Headings F2C, F2D, F2L and F2Q. To facilitate ratio-shift in a change speed gear particularly for a milling machine spindle drive, wherein gear clusters C4, C5, E4, E6, E1, E2 splined on shafts C, E are selectively axially slidable, for ratio change, by forks 10 acted on by double-acting hydraulic pressure servomotors 12, a gear-shaft B is slowly oscillated during shift by an electric motor 110 acting thereon through an epicyclic gyratory reducing gear, a crank 130, a connecting link 136, a crank 138 and an hydraulic pressure-actuated clutch 140 energized upon rotation of the motor. The slidable gear clusters are normally locked against axial movement by a common, spring- urged, pivoted latch 26 acting on the forks 10 through plungers 24 and balls 23 engaging V- grooves 22 in fork-attached rods 21. The latch is positively secured in its locking position by a bolt 27 integral with a valve piston 28 normally covering a valve port 29. A gear pump 160 driven by the motor 110 draws from a sump 180 and feeds, through a distributer 182 having a relief valve 184, a line 186 to energize the clutch 140 and a line 188 to first raise the bolt 27 to free the forks and then, by uncovering the port 29, selectively feed the servomotors 12 through a manual preselector rotary valve 16. The epicyclic gear comprises a gyratory planet 120 which is mounted on a motor-driven eccentric 118, meshes a fixed annulus 122, and is connected to the crank 130 through pins 124, 132 and an intermediate slotted plate 128. The clutch 140 comprises a spring-disengaged female cone 150 guided by dowels 152 on the crank 138 and axially moved to engage a male cone 154 keyed to the shaft B by energization of hydraulic servomotor cylinders 144. A gear cluster A1, A2 splined on an input shaft A, belt driven by an electric motor is manually shiftable to provide two speed ranges. Control.-The electric control circuit in Fig. 10 comprises contactors HS, SS, FS and BS controlling the electric motor 110, a coolant pump motor C<SP>1</SP>, the spindle motor S, a feed motor F<SP>1</SP> and an electromagnetic brake B<SP>1</SP> for the spindle. A spindle reversing switch SR is also provided. Energizing coils SC, FC, BC, HC for the contactors are controlled in a secondary circuit energized from a transformer T. Relay switches, e.g. SC1, HC2 are normally in the positions indicated and are actuated on energization of the corresponding coils. The circuit also includes spindle and feed overload switches OLS, OLF, a master stop push-button PBM, a start push button PBS, a spindle stop push button PBT, a spindle reversing switch SR1 isolating the coil SC on operation of the reverse switch SR, a " spindle-only " switch SO, a brake " on-off " switch BO, a gear change switch PBH, contacts M1, M2 of a micro-switch MS (Fig. 3), and a warning light WL. Operation of the coil SC opens a relay switch SC3 to prevent operation of the pump motor coil HC and conversely operation of the coil HC opens relay switch HC1 to prevent operation of the spindle and feed motor coils SC, FC. Operation of the push buttons PBM and PBT de-energize the spindle and feed motors and energize the brake B. In operation, with the relay switch SC3 closed, operation of the push button PBH energizes the coil HC to start the motor and thereby oscillate the shaft B, free the latch 2 and actuate the servomotors 12. On movement of the forks 10, the V-grooves 22 cam-out the balls 23 to raise the latch 26 and thereby actuate the microswitch MS to close both contacts M1, M2 respectively to complete the holding circuit for the coil HC and light the lamp WL. On completion of the shift the latch 26 is returned to its locking position, the microswitch contacts M1, M2 open, the lamp WL goes out and the coil HC and the motor 110 are deenergized. For shift of the manually movable cluster A1, A2, the push button PBH is held depressed to oscillate the shaft B during such shift.