Patent GB-1288961-A (GB)
IPC: F16H3/02
Filed: 1969-09-23
Abstract: 1288961 Change-speed and clutch control; cyclic and intermittent gearing LJKISS 23 Sept 1969 40471/69 Headings F2D F2L and F2Q A change-speed gear having positively established stepped ratios, controlled manually or automatically by punched card or tape; or a single positive clutch, is provided with a ratiocycling synchronizer, such as an elliptical gear train 78, 80, Geneva or pin-and-slot gear, which is driven continuously by the input shaft, and is engaged during ratio shift or single clutch engagement or disengagement to maintain power transmission at a ratio which is steplessly changed from that of the superseded to that of the new ratio, such ratio, in the case of a single clutch, including zero, whereby the output shaft can be accelerated from ,or decelerated to, rest, to enable its synchronous connection to or disconnection from a continuously rotating input, enabling a usual friction starting clutch to be eliminated. The actual clutch engagement or ratio shift is performed in a precisely timed sequence by an input-driven mechanical relay which is separate from the cycling gear. Change-speed gear.-An input shaft 48, Fig. 1, drives an aligned output shaft 58 through a constantly driven countershaft 54 and a sleeve 64, splined on the output shaft and having fast wheels 82B, 84B, and 86B, and a clutch dog 88B, selectively meshing respectively wheels 82A, 84A and 86A, fast on the countershaft 54, and a clutch dog 88A on the input shaft 48, to provide three reduced ratios and direct-drive by axially sliding the splined output sleeve 64 in steps to the left from neutral (shown). Constant, mesh, inclined and discontinuous staggered countershaft types are described below. Cycling shift synchronizer comprises a shaft 66 aligned with the countershaft and driven constantly thereby at cyclically varying ratio by the wheel 82A, a parallel countershaft 70, Fig. 7, and a pair of elliptical wheels 78, 80, the ratio between the maximum and minimum ratios of which corresponds to the ratio step in the main gear. The sequence, timed as described below, for a shift from first ratio, with wheels 82B and 82A in mesh, to second with wheels 84B, 84A, commences with the constantly cycled shaft 66 at its maximum ratio. Shifting the output sleeve 64 left disengages first ratio wheels 82A, 82B and meshes an output mounted wheel 90B with a wheel 90A on the cycling shaft 66. During a dwell in the axial movement of the sleeve 64, the cycling shaft 66 now accelerates the output shaft from first to second ratio speed, the minimum ratio of the elliptical gears 78, 80, so that on continued axial movement of the sleeve 64, the second ratio wheels 84A, 84B mesh synchronously, and the wheel 90A is demeshed, leaving the cycling shaft 66 again free of the output shaft 64. 2-3 and 3-4 shifts use additional synchronizing wheels 92A, 92B, and 94A, 94B. In all cases there is a positive stepless variation from one ratio to the next, up or down. Cycling start synchronizer.-The positive, and clutchless start from standing, with idling input, Fig. 1, to first ratio is as follows. A second cyclic drive produces output speeds varying steplessly from zero to a maximum corresponding to that required for synchronous engagement of first ratio with an idling input. This second cyclic gear comprises a toothed wheel 108, Figs. 1 and 13, fast to an eccentric stub 106 on the end of the constantly cycling shaft 66, and meshing elliptical internal teeth 110 in a wheel 112 secured to a shaft 114 eccentric to the cycled shaft 66. The eccentricity of this toothed wheel 108 is such that one of its teeth is on the axis of the cycled shaft 66, so that, when that tooth meshes the teeth 110, the speed of the output wheel 112 will be zero, and the wheel 112 is steplessly accelerated to synchronous speed for first ratio at the opposite tooth position. To start the load from idle neutral, shown, the output sleeve 64 is moved left to mesh an output-mounted wheel 118 with the cycled wheel 112 at the instant of its zero velocity, and during subsequent dwell, the output is accelerated to first ratio synchronism, and at that instant is shifted further left to mesh first ratio wheels 82A, 82B, and demesh 112, leaving the cycling shaft 66 free. Sequence timing is described below. Alternative cyclers.-Alternatives to the elliptical wheel cyclers are Figs. 14, 15 (not shown) being a driving crank pin engaging a radial slot in an eccentric driven member, Figs. 18, 19 (not shown), being a radially grooved driving arm engaged by a crank-pin on an eccentric driven member; and the Geneva drive of Fig. 17 wherein a pin 122 on a driving arm engages successively in three radial slots 128 in an eccentric driven disc 126, having also three stop lugs 130, held by a lug 124 on the driver whilst the drive pin 122 is on the idle stroke giving zero output speed, the output disc being alternatively accelerated and decelerated on opposite sides of this idle-lock position. Shift mechanism.-The complete sequence of synchronizing and shift is performed by a mechanical relay in one half-revolution of a cam 132 carrying an axially movable shift sleeve 140 having radially inward rollers engaging the cam groove 138 and a shift yoke 148 engaging the output sleeve 64. The cam 132 is secured to a shaft 174 rotated in the appropriate direction for up or down shift by being clutched by a faciallytoothed double relay clutch member 182 to either one of two freely mounted wheels 158, 170 rotated continuously in opposite directions by the input shaft 48. The ratio shift, or starting shift, are initiated at the precise instant (described below) when the cycling synchronizer (above described) is at its maximum, minimum or zero output position as appropriate for downshift, upshift or start. The relay clutch 182 is engaged by a shift-yoke 190 operated by a polarized solenoid 324, Fig. 3, and is disengaged at the end of a half revolution by a cam 228 on one or other side of the relay clutch member 182, which is then retained in central neutral position by a detent 186. Sequence timing.-Shift and start are initiated by a handle 248, Fig. 3, which is manually moved laterally against spring resistance out of one of a number of lock-notches 346, representing gear settings and Idle (shown), permitting the handle to turn a lever 246 to a selected setting, where it is locked on release of the handle. Movement of the lever 246 shifts a bar 234 having a cam depression 234c for closing one or other of two limit switches 292, 294, according to the desired direction of shift, which completes a circuit (Fig. 20, not shown) through one or other of two timing switches 362, 368, closed at a precise instant for upshift or downshift by cams 359, 361, constantly input-driven through a worm 350, Fig. 1, and transverse shaft 354. Completion of this circuit energizes one or other of two interlocked relays 364, 370, Fig. 3, closing hold-on contacts, and also energizing the polarized solenoid 324 to shift the relay clutch 182 in one direction or the other to drive the selector cam-shaft 174 clockwise or counterclockwise (from the left) for up or down shift. The consequent movement of the shift sleeve 140 on the cam 132 also causes, through a rocker 282, axial movement of a follow-up switch bar 274, which carries the limit switches 292,294, one or other of which has initiated shift by action of the cam surface 234c. At the completion of the shift this surface 234c releases the operative limit switch 292 or 294, breaking the circuit to the relay solenoid 324. The hold-on contacts are released by a normally closed switch 377, operated by a notched track 375, Fig. 3, on the switch bar 274, which breaks the shift circuit after start of the shift, and only remakes it on completion, which ensures shift completion before a new shift cycle can be initiated. A pointer 288 on the follow-up switch bar 274 indicates gear setting at 290, "I" being declutched idle. An equivalent pneumatic or hydraulic circuit is given in Fig. 21 (not shown).  In Figs. 23-29 (not shown), the main and synchronized gears are in constant mesh and clutched to the output shaft by a common axially-movable splined output sleeve having a clutch dog at each end, selectively and internally clutching the wheels as the output sleeve is shifted axially by half-revolution steps, as above described, by a Geneva mechanism driven by a transverse bevel-geared shaft carrying a pinion engaging circumferential rack teeth on the sleeve In Figs. 30-33 (not shown) the main and synchronizing gears are arranged parallel, and shift is effected by a single common wheel (560) sliding on a splined output shaft between them. The two countershafts are inclined to the main shafts and the gear wheels which they freely carry are mounted on inclined bearings relative to the shafts, so that adjacent peripheries of the wheels are at a constant distance from each other and from the single wheel shifted between them to mesh selectively the various wheels for synchronizing and shift. In Fig. 34 (not shown) one cycling device (pin- and-slot 635) is used for synchronizing 1-2 and 2-3 shifts, whilst another separate cycler (645) is used for synchronizing the 3-4 shift the ratio interval of which is in a different proportion from that of the other two named shifts. Different sized wheels (622A and 622C) on an input shaft engage individual wheels (622B &c.) on individual output shafts which are radially offset and coupled so that a single wheel (630), splined to the output, can mesh them selectively by straight axial movement. Clutch only.-In Fig. 35 (and Figs. 36-42, not shown) the cycling synchronizer is used for clutching and declutching only, there being no variable-ratio gear other than the synchronizer. An. input shaft 660 carries a fast clutch member 674, facial teeth on which are to be clutched by those on a clutch member 678 fast with a sleeve 676, splined to an aligned output sh