Patent GB-546023-A (GB)
Title: Improvements in preselecting change-speed drives for lathes and like machine tools
IPC: B23Q5/18
Filed: 1940-11-21
Abstract: 546,023. Turning. TRIGGS, W. W. (Warner & Swasey Co.). Nov. 21, 1940, No. 16748. [Class 83 (iii)] A change-speed transmission device for controlling the speed of the movable part of a machine tool such as the spindle of a turret lathe, or the aprons of the turret slide and the cross slide carriage is constructed with an indexable member 95, Fig. 4, which can be set to preselect the required change of gear by adjusting a pair of wheels 92, 93 adapted to control valves 71, 72, 73, 74, Fig. 6, which control the position of three step gear cones to set the transmission ratio to one of twelve combinations by controlling the supply of operative fluid to cylinders 58, 60, 65, 69, Fig. 6. When the member 95 is set a lever handle 125, is raised in a vertical slot 124 and operates a valve 112 to connect fluid pressure to a cylinder 109 and operate a piston 108 which by means of a lever 102 and a pair of yokes 96, 99, Fig. 4, moves the wheels 92, 93 towards one another and according to the setting of the member 95 certain pins 90 of valve rods of valves 71, 72, 73, 74 are operated in order to control the supply of fluid to the cylinders 58, 60, 65, 69 and so shift gear cones 39, 40, 41 ; 49, 50 ; 52, 53 to the required positions. The first of these is splined to a shaft 35 geared to the main drive shaft 28 through gears 36, 37, 38; or in a reverse direction through gears 33, 34, or it can be declutched when a clutch 32 is in neutral. This clutch is controlled by the lever 123 which can be moved in a horizontal slot connected to the vertical slot 124, the direction of rotation depending on whether the lever is moved to the right or left, the control being effected by a valve 131 which controls the supply of fluid to a pair of superposed cylinders fitted with pistons 147, 150. The piston rod 148 controls the clutch 32 and can be given three positions of adjustment namely (a) that shown in Fig. 6 in which the larger piston 150 is raised and maintains the piston 147 in a mid position in its cylinder ; (b) in which the piston is lowered and inoperative and the piston 147 in lowered position ; (c) ditto with the piston 147 in raised position. In a modification, Fig. 11, electromotive power means and control switches therefor are used in place of fluid motors and valves. In this form the gear shifting rods 171, 175 which are required to be set to one of two positions are operated by the energization of oppositely wound electromagnets 168, 169 : 172, 173, but the gear rod 157, and the clutch rod 176 which are required to occupy one of three positions are controlled by electromagnets 160, 163: 181, 183 which determine the extreme positions of these rods, and the intermediate positions (corresponding in the case of the clutch to the declutched position) are determined by slides 165, 184 having V-recesses which overlie the core bar 159 and lever 158, and the core bar 180 and lever 183, and the slides are controlled by electromagnets 166, 185 of greater capacity than the adjacent magnets. The selector wheels 82, 83 are operated by electromagnets 230, 231 controlled by a switch 233, and these wheels operate switches 187, 188, 207, 218 which control the energization of the electromagnets referred to which control the gear rods and the clutch.