Patent GB-656665-A (GB)
Title: Machine tool change speed gear
IPC: B23Q5/14
Filed: 1948-06-04
Abstract: 656,665. Change-speed gear. WARNER & SWASEY CO. June 4, 1948, No. 15104, Convention date, June 4, 1947. [Class 80(ii)] Three fluid-pressure actuated sliding gear-cones 69, 70, 72, 73, and 78, 80, 81, Figs. 2 and 3, providing twelve speed-ratios in the drive to a lathespindle 32 from an input shaft 34, are controlled by a preselective rotary distributer - valve 100, Fig. 18A, and an executive shiftcycle initiating valve 119, Fig. 18, controlling shift-circuits which function automatically on shift-completion to restore the executive valve 119 to its normal position. During a shift a fluid-pressure actuated main friction clutch 35, Fig. 2, is disengaged and an inching planetary-gear drive 48 is established, to facilitate mesh, and there is a time-delay valve 111 to ensure that these actions precede the supply of fluid-pressure to the shift-motors. The planetary inching-gear 48 also provides a working reverse, and braking at 57 is also provided, both controlled by the hand-lever 123 of the executive-valve 119. Gear-arrangement. In forward drive the gear is driven through the main frictionclutch 35, Fig. 2, which drives through a wheel 47 an axially-fixed cluster 66, 67, 68 on a first countershaft 65. For reverse the same cluster is driven at the same speed through a larger wheel 64 and the planetary gear, rendered effective for reverse by disengaging the main-clutch 35 and braking at 58 a freely-mounted planet-carrier 53, the planets of which mesh a sun 48, permanently fast on the input shaft 34, and a ring-gear 49 permanently fast to the wheel 64. The slow forward inching drive, also through the wheel 64, is effected by braking at 59 a second ring-gear 50, having two teeth more than 49 and meshing the same planets. A third brake 57, on the wheel 64, provides for spindle-braking, the three brakes being applied by fluid-pressure piston-motors 61, 62, 63, Fig. 18. The first countershaft 65, Fig. 2, drives the spindle 32, Fig. 3, through a second countershaft 71 carrying the two sliding double wheels 69, 70 and 72, 73 each of which has two gear-positions, and a third countershaft 76 having fast-wheels and a fourth 79, having a sliding triple-wheel 78, 70, 81, which has three gear-positions. The double sliding wheels 69, 70 and 72, 73 are operated respectively through shift-rails 86, 88, Fig. 18A, by double-acting piston-motors 97, 98, the triple-wheel 78, 80, 81 being operated through a shift-rail 93 by a three-position compound piston-motor 99, 251, the piston 251, slidable on the rail 93, having a greater area than 99 so that, with pressure fluid supplied continuously to its left face, the piston 251 is stationed in the position shown, whilst the piston 99 can be moved to either its extreme right position shown, or its central position, by directing pressure to either of its faces. With pressure exhausted from the left face of the large piston 251 and supplied to the right face of the small piston 99, the latter moves to its extreme left position, taking with it the large piston. Fluid circuit. Pressure from a continuously driven pump 128, Fig. 18, relieved at 128A, is supplied to an inlet channel 132 in the headstock, which channel, like many of the others shown, is formed by milling a groove in the headstock and closing it by the valve-mounting cover-plate 117, to dispense with piping. The inletpressure passes from the channel 132 through a channel 133 to the main controlvalve which comprises the executive-valve 119 axially slidable, by lateral movement of a hand-lever 123, in a rotary-valve 118 which can be turned, by turning movement of the same handle 123, into any of four rotary positions, F, N, B, R, directing pressure selectively to the main clutch 35, and inching-gear pistons 61, 63, to give neutral (clutch disengaged) and braking in the mid two positions, and forward and reverse at the two outer extreme positions. Stops 121A, 121B, prevent turning movement of the handle 123 except between neutral and braking positions in its normal lateral position I, and in a fully depressed lateral position III, shown in Fig. 18. it being necessary to pull out the handle against spring-pressure 124, to an outermost lateral position II before it can be turned into or from either of the two outer rotary positions giving respectively forward and reverse. Pressure reaches the hollow interior of the rotary twelve-position preselective distributer-valve 100, Fig. 18A, through the main control-valve 118, 119, the time-delay valve 111, and a line 151. The two uppertwo-position gear shift-rails 88, 86 have pairs of grooves 240, 246 and 244. 245, and the lower, three-position, rail 93 has outer L-shaped passages 248, 249 and an intermediate diametrical passage 250 for completing a fluid circuit between lines 152, 163 in gear-positions only, so as to return the executive-valve 119, and with it the handle 123, to normal position I at the completion of a gear-shift, as described below. Sequence of a simple ratio-shift in forward drive without reversing or braking is as follows. Initially with the machine driving forwards in a given work cycle, the handle 123 is in its normal lateral position I, with the inner executive-valve 119 at its extreme leftward position, in which pressure flows from the inlet port 132, Fig. 18, to the main clutch 35 through channel 133, now-communicating valve-ports 167, 172, clutch-supply port 146, Fig. 19, and line 147, ports 172, 146 being in communication in the forward rotary position of the handle 123. Figs. 18 and 19 show the handle in the forward rotary position F. After having preselectively turned the distributervalve 100, Fig. 18A, to the required position, the operator pushes the handle 123 to its extreme inward lateral position III shown in Fig. 18, moving the executive valve 119 to the extreme right and cutting off pressure supply from the port 167 to the clutch supply-port 172, and exhausting the latter at 174B, so that the main-clutch 35 disengages. At the same time pressure flows from the port 167 to port 166 and channel 135, and thence simultaneously through a pipe 138 to the inching-brake 59, which starts the inching drive, and through a pipe 137 to the time-delay valve 111. At this time, pressure acting on the smaller right face of the time-delay valve-piston 112, through a constantly open pressureline 134 from the main pressure-inlet 132, holds the valve-piston 112 in its extreme leftward position, in which no pressure is supplied to the feed-line 151 of the distributer-valve 100. The pressure supplied through the pipe 137 to the left of the timedelay valve 111, passes through a labyrinth restrictor 113 and after a predetermined delay, reaches the larger left face of the delay-valve piston 112, which, overcoming the opposing pressure on its smaller right face, moves to the extreme right, (position shown in Fig. 18), pressurizing the distributer-valve feed-line 151 from the constantpressure pipe 134' through ports 188, 190, this pressurization taking place slightly before pressurization of the line 152 leading to the shift-rail grooves 240, &c. Fig. 18A, so that the shift commences and the shiftrail grooves move out of register with the line 152, communication of which with the return line 163 is thus blocked. Completion of the shift again registers the shift-rail grooves 240 &c., Fig. 18A, grooves 240 &c. so that pressure in the feed-line 134 passes through the now-communicating lines 152, 163, valve passages 192, 186, lines 150, 149 to the right face of the executive valve 119, such pressure acting against the hand-pressure to force the handle 123 outwards to the normal lateral position I, in which position the pressure inlet port 167 again supplies the clutch-port 146, Fig. 19, through the valve-port 172, so that the main-clutch 35 re-engages; the port 166 is exhausted at 169, thus exhausting the inching-brake and time-delay valve lines 138, 137; and ports 175 exhaust the left face of the time-delay valve-piston 112 through the line 164 so that inlet-pressure still acting constantly on its right face through the line 134 moves the delay valve-piston 112 back to its extreme left position, exhausting the distributer and the shift-rail groove feed-lines 151, and 152. This simple shift sequence without change of direction or braking is possible in any of the four rotary positions F, N, B, R, of the handle and without turning movement thereof, If, however, the shift requires also reversal or braking the following sequence, involving shift in neutral position is required. The handle 123 is first pulled fully outwards from normal lateral position I to outer lateral position II in opposition to the spring-loaded peg 124 to allow the handle to pass over the fixed stops 121A or B. The handle is now turned to neutral position N and the preselected shift is made in this rotary position by moving into lateral position III and releasing back to I again as above described, after which the handle is again pulled out to lateral position II and turned to the required F, B or R position, with final release to position I. Simple change between neutral, forward, reverse or braking, without ratio-shift, is made by turning movement of the handle after first pulling it out to lateral position II to free it from the stops 121A or B. Turning the main-valve 118 to position R causes a port 173, Fig. 19, to supply the lines 140, 141 of the reversebrake 61; or to positions B and F to supply the lines 143, 144 of the input brake 62 or 146, 147 of the main-clutch 35 respectively, these lines being exhausted in the neutral position N.