Patent GB-653481-A (GB)
Title: Improvements in or relating to a machine tool transmission assembly
IPC: B23Q5/04
Filed: 1948-09-06
Abstract: 653,481. Milling-machines. KEARNEY & TRECKER CORPORATION. Sept. 6, 1948, No. 23396. Convention date, Sept. 15, 1947. [Class 83 (iii)] A milling machine of the knee and column type comprises a main driving shaft 26 driven from an electric motor 20 and having mounted thereon a reversing mechanism 31 which is operatively connected to a transmission 32 driving a cutter spindle 12, the shaft 26 also driving a feed transmission 34 contained in the saddle 17, and mechanism being provided to reverse the direction of rotation of the spindle transmission without changing the direction of rotation of the feed transmission. The reversing mechanism comprises bevel gears 38, 39, Fig. 2, and a clutch 40, splined to the shaft 26, which is movable from the neutral position shown to engage either of the bevel gears by means of a manually - actuated shifter fork 45, Fig. 3. The spindle transmission includes slidable gear couplets 59, 60, 70, Fig. 3, which are positioned to provide a desired spindle speed by means of a control mechanism 80, Fig. 2. The latter comprises a handle 81 having attached thereto a spring-pressed plunger 83 carried in the end of a crank 84. The plunger is withdrawn and the crank rotated until the desired spindle speed is obtained, as indicated by a rotatable dial 82. Rotation of the crank effects rotation of a dial gear 92 and of a cam gear 93 provided with a cam groove 94 which receives followers attached to shifter forks 96, 99 which are associated with the gear couplets 59, 60. The gear couplet 70 is positioned at the same time by means of a shifter fork 102. The feed transmission for the table 16 and saddle 17 is driven from the shaft 26 by means of take-off mechanism 33 which includes a bevel gear 112 engaging a bevel gear 115 which receives a splined shaft 117, the lower end of which has keyed thereto a helical gear 123, Fig. 7, which engages and drives a helical gear 124 keyed to the end of a shaft 125 to effect movement of the table and saddle at a selected feed rate or for driving the table at rapid traverse rate. The rapid traverse drive includes a clutch 129, operated by a manually-actuated lever 155, which drives a bevel gear 133 through an overrunning clutch 134. The table and saddle are driven at one of a plurality of feed rates from the shaft 125 through speed-change transmission comprising slidable gear couplets 162, 170, 175 which are positioned by means of a control mechanism 181, Fig. 1, similar to the mechanism 80. The bevel gear 133 is operatively connected to a pair of reversing gears 140, 141 mounted on a screw shaft 142 which is manually operable by a handle 145, the extent of table movement being determined by a dial 146. The gears 140, 141 are associated with a clutch 148 which is moved by a handle 149, the movement of the table being stopped by trip dogs 150. The saddle 17 can be power driven at feed rate by means of a bevel gear 187 which meshes with reversing gears 188, 189 on a screw shaft 190, the gears being associated with a clutch 191 operable by a lever 192. The knee 18 may also be power driven at feed rate. The knee and saddle may be manually fed. In a modification, Fig. 8 (not shown), the main driving shaft is driven by a manually-operated clutch mounted therein. Brakes and stop-motions.-A control switch 35 is connected with the motor 20 and with a zero speed switch 37 mechanically driven from the driving shaft 26 to enable the spindle 12 to be braked and the feed transmission to be brought to a standstill. Framings.-Two overarms 14 support a cutter-carrying arbor which may be used instead of the cutter 13. The shaft 26 is journalled in a frame 29 which carries the spindle speed controlling and indicating mechanism, the frame together with the shaft and spindle mechanism being removable as a unit from the column 10. Lubricating machines.-A gear 114 keyed to the shaft 112, Fig. 2, forms part of an oil pump which lubricates the moving parts of the spindle transmission.