Patent GB-754036-A (GB)
Title: Change speed transmission and control therefor
IPC: B23Q5/18
Filed: 1954-06-14
Abstract: 754,036. Change-speed gear. WARNER & SWASEY CO. June 14; 1954 [Aug. 14, 1953]. No 17386/54. Class 80(2) Eight individual hydraulically or electrically actuated friction clutches 51 &c., providing sixteen ratios in a parallel gear drive from an input shaft 36 to a lathe-spindle 74, are controlled by selectively-apertured valve-actuating discs 117, 119, which are turned together to pre-select a ratio which is subsequently established by moving the discs bodily axially towards each other to move axially certain ones of two-position selector-valves 87 ... 90 (in the case of hydraulic control). grouped between and at different radial distances about the common axis of the discs 117, 119, the selectively positioned apertures in which receive the reduced ends 92 of certain of the valves to permit their movement by the opposite disc in one or other pre-selected direction. The first six ratio clutches are arranged in pairs 51, 52; 58. 59; and 65. 66 on first three intermediate shafts 49, 55, 63, the last pair of clutches 71, 76 being respectively on a fourth intermediate shaft 69 and the final output spindle 74. Each selector-valve 87 ... 90 controls one pair of clutches, as above, a different one, of each pair of which is pressurized in each end position. of the corresponding valve whilst the other clutch is drained. All sixteen speeds are reversible by two similar input clutches 44, 45 on a 'reversing shaft 40 the clutched wheels of which are driven by the-'input shaft 36 directly and through an idler 41 respectively. The forward-reverse clutches 44, 45 are controlled by a separate valve M, the control handle 153 of which has positions intermediate the extreme forward and reverse, giving neutral and spindle braking, the last-named by engaging both clutches 51, 52 of the first, pair together. A leveroperated executive shaft 133 effecting the gear-establishing approach movement of the pre-selector discs 117, 119, has also an opposite movement directly controlling the last one 90 of the individual selectorvalves for rapid shift to a low speed, as for use in tapping. Selector-valve group. The ratio selectorvalves 87 ... 90 are grouped about an axially movable and rotatable shaft 115 carrying the two apertured selector discs. the one, 117, rigidly. -the other, 119, splined and loaded leftwards by a spring 118. Fig. 14, against reversing levers 126 centrally pivoted ona fixed bracket 123. Leftward axial movement of the shaft. 115 establishes a, pre-selected ratio by direct leftward movement of the selector-disc 117. and, through the reversing levers 126. eaualizedrightward movement of the selector disc 119. Such shaft movement is effected by actuating an executive lever to rock a shaft 133 counterclockwise whereby a fork 130 on the shaft 133 acts through' a'collar 127. freely mounted on the shaft 115 and a shoulder 128 to move the shaft 115 leftwards. Clockwise movement of the executive shaft 133 has no effect on the selector-disc shaft 115. the collar 127 merely sliding rightwards thereon in opposition to a spring 129. -but this movement acts on the single selector-valve 90 through a lost-motion connection 134. 136 which permits the gear establishing counterclockwise movement of the connection 134 to be without effect on the Selector-valve 90 but which for the clockwise movement, causes the selectorvalve 90 to be moved rightwards to select the low-speed, final clutch 76, permitting rapid selection of a low speed. The selector discs 117, 119 are turned to pre-select by a knob 113 splined to the disc-shaft 115 andhaving a graduated dial 111 indicating the ratio. which latter is also indicated at a window 151 bv a graduated drum 150 connected by bevel and spur gears 144 including an elongated idler with the disc shaft 115. A notched disc 138 keyed on the shaft 115 is engaged by a spring-loaded lever-mounted roller detent (Fig. 15, not shown) to locate gear positions. Forward-neutral-brake-reverse valve M comprises a ported rotary plug 151, Fig. 5, to which is hinged at 175 a control lever 153, which can be turned freely from either extreme forward or reverse position' to intermediate neutral and brake positions, but which must be pulled outwards against spring-resistance 81 to clear a notched obstruction 180 before return movement to forward or reverse positions can be made. A spring detent locates the valve plug 151 in selected positions, this and the valve porting being. in Figs. 7 to 12 (not shown). Fluid circuit. A pump 95, Fig. 3, drawing from a reservoir 96, pressurizes a gauge 99 and lines 98, 100 the former supplying the reverse-brake valve M, the latter supplying three 87, 89 of the selectorvalves. the fourth. 90 of which is supplied through the reverse-brake valve M and a line 108. which latter in the neutral position of the valve M is drained at 105 so that both the last clutches 71, 76 are disengaged. The last three selector-valves 88, 90 all drain through a common line 107 but the first, 87. drains only through a line 104 and the reverse-brake valve M in all positions, of the latter except brake. In brake position the valve M cuts off the drain 105 from the line 104 and substitutes a pressure connection, so that whichever of the first pair of clutches 51, 52 would otherwise be drained through the selectorvalve 87 is now pressurized. Both clutches 51, 52 are thus engaged together for spindle braking through the effective gear train. Relief-valves 102, 106 are provided in the lines 100, 104 respectively. The clutches may be as described in Specification 707,515.