Patent GB-525449-A (GB)
Title: Improvements in or relating to milling machines
IPC: B23C1/06
Filed: 1939-02-21
Abstract: 525,449. Milling-machines. BROWN & SHARPE MANUFACTURING CO. Feb. 21, 1939, No. 5771. Convention date, Feb. 23. 1938. [Class 83 (iii)] A milling machine is provided with a swivelling spindle-head which is adjustable through substantiallya full revolution about the axis inclined to the spindle axis and has power transmission means comprising a driving element coaxial with the swivel and arranged to impart axial feed to the spindle in all positions of adjustment. The column 20 is fitted with the usual knee 26 carrying a saddle 24 and table 22. A motor 36 is connected through internal gearing 42, a shaft 44, gears 46, and change speed gearing 50 to a vertical shaft 56 which drives the table mechanism. The shaft 44 also carries a gear 60 operating the spindle-driving train which comprises gears 62, 64, 66, and a shaft 68 coaxial with the swivelling head 32. The shaft 68 carries a bevel gear 70 engaging a bevel gear 72 splined on the spindle and having a sleeve portion mounted in roller bearings 80 in the spindle-head. The column carries a ring member 34 having a spigot portion 86 engaged by an annular surface 88 on the spindle-head which is adjustable through 360 degrees and secured by clamping bolts 104. For effecting axial feed of the spindle, the vertical shaft 56 is connected by a universal shaft to a shaft 109 connected by reversing bevel gearing 114 to a gear 116 on shaft 118 which through gears 120, 122, shaft 124, and gear 126 drives a central gear 128 coaxial with the swivel mounting. The gear 128 is connected through idler 130 to a gear 132 on a clutch shaft 134 which may be coupled to the hub of a spiral gear connected through spiral gearing 140, 144 to a nut 146 coacting with a sleeve 148 sliding without rotation on a stationary sleeve 149. The spindle 30 rotates within the sleeve 148 and is connected to move axially therewith by a bearing 151 interposed between the spindle and a cap member 152 threaded into the member 148. The spindle 30 is also supported at its lower end in bearings 160, 162. in a slidable bearing member 164. The gears 130, 126 engage opposite ends of the central gear 128 so that they can pass each other during the angular adjustment of the swivel head. Manual control of the reverse of the axial feed is effected from a lever 170 which actuates the reversing bevel gearing 114. The feed adjustment of the spindle is determined by mechanism comprising a slide 197 movable with the spindle and carrying an abutment screw 199 coacting with a relatively stationary stop member 201 on housing 32. A screw which secures the slide 197 to the bearing 164 also carries a clamping lever 203 actuating a block 204 to secure the slide in any required axial position. The axial power feed in either direction may also be disconnected automatically. For this purpose the stop 201 is formed on a plunger 212 which when the abutment 199 engages the stop actuates a lever 216 operating a link 220 connected to the hand lever 180 which operates the axial feed clutch 138. To terminate the upward feed a block 200 on the slide 197 acts on a follower 224, carried by the link 220. For manual axial feed of the spindle a cross shaft 142 carrying the spiral gear 140 is provided with stub ends either of which may receive a hand wheel 226 which is axially located by one of the plungers 228, 230, Fig. 3 (not shown).