Abstract: A combined powershift transmission and main clutch assembly for a vehicle includes a casing containing an input shaft and an output shaft. A planetary transmission is disposed within the casing and is co-axially mounted around the input shaft. The planetary powershift unit includes a sun gear and an annulus gear interconnected by one or more planet gears carded on a planet carder. A first one of the sun gear, the annulus gear, and the planet carder is connected to the input shaft, while a second one of the sun gear, the annulus gear, and the planet carder acts as an output member of the planetary powershift unit. A first clutch is disposed within the casing and co-axially surrounds the output shaft for drivingly connecting the output member of the planetary powershift unit with the output shaft.

Abstract: A system for controlling the selection of the operative ratio of a vehicle powershift transmission driven from an engine via a main clutch. The system includes a clutch status sensor for sensing engaged and disengaged conditions of the main clutch. A selector is provided for selecting the operative ratio of the transmission. Also, a control circuit is provided which includes a ratio-change modulating function which, when the main clutch is engaged and a change to a non-adjacent ratio is selected, invokes a serial routine which ensures that each intermediate ratio between the current ratio and the selected ratio is engaged for a moment to ensure a smooth substantially jerk-free progression between the current ratio and the selected ratio. When the main clutch is disengaged and a change to a non-adjacent ratio is selected, the control circuit invokes a direct routine which permits changes from a current ratio to a non-adjacent selected ratio without engagement of any intermediate ratio.

Abstract: A control system for the control of a fluid pressure-operated clutch (12) is provided. It includes a fluid pressure-operated clutch actuator (14) and a source of pressurized fluid (15). A fluid flow control valve (18) controls the flow of pressurized fluid to and exhaust of fluid from the actuator. A manually operable clutch control member (19) (e.g. a pedal) is connected via a linkage (20) to the valve (18) to enable engagement/disengagement of the clutch by operation of the control member. An electrical actuator (33) is also provided for operation of the valve, and hence clutch, independently of the manually operable clutch control member. The system further includes a sensor (19a) for sensing the position of the clutch control member and an electrical control circuit (21) for independent control of the valve in response to predetermined vehicle operating criteria.

Abstract: A transmission selector mechanism including two selector members (50, 51) connected with two coupling members (6, 7) each coupling member being axially slidable in both directions either side of a neutral position to couple a selected one of a pair of gears (10, 12: 11, 13) to an associated shaft (4, 5). The coupling members are connected with the selector members via an epicyclic gear train (56, 55, 54, 52). A first element (52) of the epicyclic is connected with one selector member (50), a second element (56) of the epicyclic is connected with one coupling member (6), and a third element (55) of the epicyclic is connected with the other selector member (5) and the other coupling member (7). The arrangement is such that by appropriate movement of the two selector members (50, 51) both coupling members (6, 7) can be positioned either on the same or opposite sides of their respective neutral positions.

Abstract: A transmission ratio selector mechanism for a transmission having two ratio selector couplers both of which must be engaged to provide drive through the transmission. The selector mechanism includes a selector shaft which is rotatable about its longitudinal axis and also axially moveable parallel to its longitudinal axis. Rotation of the selector shaft is arranged to operate one of the couplers via a mechanical linkage including a twin-armed member and a pivoted lever while axial movement of the shaft operates the other coupler via a fluid pressure-operated actuator and an associated control valve mechanism. An interlock is provided to ensure that the fluid pressure-operated coupler is always engaged before the mechanically operated coupler. The interlock comprises a formation which is movable with the shaft and cooperates with a formation movable with the coupler which is to be engaged first.

Abstract: A selector mechanism for a gearbox in which speed change couplers (28, 29) and a range change coupler (34) are operated by the same selector lever (47). Lever (47) operates the speed change couplers to engage a plurality of drive speeds when moved from a neutral plane to speed selection positions (1, 2, 3, 4) in a speed change gate and operates the range change couplers when moved to discrete range change positions (H,L). The selector mechanism is arranged so that on movement of the selector lever (47) out of the speed change gate towards a desired range change position (H, L) the range change coupler (34) is moved towards an engaged position for the desired range and on movement of the selector lever back towards the speed change gate from the desired range change position the movement of the range change coupler (34) is completed to engage the desired range.

Abstract: A power take-off drive unit for use at the front of a tractor, in which a housing supports input and output shafts for rotation with the input shaft above the output shaft and a gear train connecting the two shafts. An oil-cooled clutch is provided within the housing which is mounted concentrically with the higher input shaft. Coolant oil is supplied to cool the clutch and a scavenging pump is driven from the input shaft for scavenging coolant oil from within the housing to ensure an oil level within the housing below the clutch to minimize the power losses due to churning of the clutch within the coolant oil while still immersing at least part of the gear train. A bearing support for a pivot of a front axle of the tractor is also carried by the housing.

Abstract: A planetary gear assembly (10) having a stationary housing (18) and co-axial input and output shafts (12, 14) having the same diameter and spline formations of the same cross-sectional form on their adjacent end portions (12a, 14a). First and second sun gears (13, 15) are splined one onto each shaft end portion, a carrier (20) is rotatable about the axis of the input and output shafts, and planet gears (22, 23) carried by the carrier mesh with the sun gears. A brake (31) is provided to hold the carrier stationary so that the assembly operates in its planetary ratio. A clutch (27) is provided to clutch a torque transmitting member (24) which is splined onto either the input or output shaft to the carrier (20) to lock-up the assembly and provide a direct drive ratio.

Abstract: A vehicle transmission having a housing within which is disposed a multi-ratio main change speed gear set (X) and a first range change gear set (Z) in series and in which the speed and range changes are effected by selector forks (100, 101, 102) which are mounted on and axially movable relative to a single selector fork rail (105) which is held stationary (108) relative to the housing. Additionally selector forks (103, 104) for a second range gear set (Y) and a creeper gear facility (C) may be mounted on and movable relative to the same selector fork rail (105). The housing is also provided with an access aperture (132) and the selector fork rail (105) can be released and slid axially within the housing to allow removal of the selector forks (100, 101, 102, 103) one by one from one end of the rail (105) via the aperture (132).

Abstract: A transmission ratio selector mechanism having an upper manually operable gear lever (120) which is mounted (139, 250) intermediate its ends for pivoting about two perpendicular axes and a lower lever member (134) which is pivoted in a fixed mount (136) at its lower end (135) and is connected at its upper end (137) with the lower end (138) of the gear lever (120). The lower lever (134) is interconnected (133) intermediate its ends with a ratio selector shaft (112) whose longitudinal axis passes through the fixed mount (136). Pivoting of the gear lever (120) about one of the perpendicular axis causes axial displacement (W1, W2) of the selector shaft (112) in a direction parallel to its longitudinal axis and pivoting of the gear lever about the other perpendicular axis causes turning of the selector shaft about its longitudinal axis to move one or more ratio selector forks (101, 102).

Abstract: A tractor draft sensing apparatus in which a shaft (14) is supported at laterally spaced locations (15) on a tractor and carries at locations (22) outboard of the shaft supports a pair of lower draft links (10) so that the imposition of a draft link (10) to monitor the deflection of the shaft (14) (or an extension (28) thereof) to provide a signal indicative of the draft force being imposed on each draft link. In a form of the sensing system for use on a tractor in which the draft links are raised by external piston and cylinder assemblies whose lower ends are secured to the tractor at locations outboard of the draft links and in alignment with the longitudinal axis of the shaft, the lower ends (36) of the cylinders (32) are connected with the tractor by hollow pins (33) through which the shaft (14) (or an extension (28) thereof) extends.

Abstract: A vehicle transmission with parallel input (30) output (19), and idler (35) shafts each provided with first (28,31,34) and second (29,32,33) gear wheels. The first gear wheels (28,31) on the input and output shafts are in constant mesh and the first gear wheel (34) on the idler shaft meshes with the input shaft first gear wheel (28) alone, while the second gear wheels (29,32) on the input and output shaft are in constant mesh and the second gear wheel (33) on the idler shaft meshes with the output shaft second gear wheel (32) alone. A synchromesh clutch unit (36) selectively connects the input shaft first and second gear wheels with the input shaft and a non-synchromesh clutch unit (37) selectively connects the output shaft first and second gear wheels with the output shaft to obtain a number of different output shaft ratios.

Abstract: A transmission ratio selecting mechanism including a ratio selector means (typically a hand lever), first and second ratio coupling members (36b,37 ) movable to select a number of ratios in the forward and reverse drive directions of an associated transmission, and linkage means (65,63,54,61,62,59,57,60,65,63,64,70,71,68,67,69) for moving the ratio coupling members in response to movement of the ratio selector means. The ratio selecting mechanism includes disconnecting means (72,73,63,64) for disconnecting one (37) of the ratio coupling members from the selector means during selection of the reverse ratios of the transmission.

Abstract: A tractor draft sensing apparatus in which an elongated sensing shaft is supported in spaced fulcrum supports and carries a pair of draft links on its end portions located outward of the supports. Draft force signals are provided by an elongate member which is attached at one end to the shaft, extends generally parallel to the shaft, and carries at its other end a follower which engages a cam and pivots the cam to give a signal proportional to shaft bending and hence to the draft forces applied to the shaft. The elongate member also carries a separate follower which engages a guide surface on a guidance member to ensure that the elongate member moves relative to the shaft generally in a horizontal plane only during shaft bending. The shaft may also be shaped so that its neutral axis between the fulcrum supports is displaced transversely of the shaft, generally in the direction of application of the draft force, relative to its neutral axis location within the supports.

Abstract: A brake assembly for engaging the periphery of a rotatable member, the brake assembly being energized by rotation of the rotatable member in either direction. The brake assembly includes a movable brake shoe which may be forced into contact with the periphery of the rotating member. The brake shoe has spaced apart rollers which are held in engagement with converging ramps on a wedge block. The brake shoe is permitted to shift laterally with respect to the ramps, and as the brake shoe engages the rotating member one of the rollers will move downwardly along one of the ramps to affect self-energization of the brake shoe. The wedge block is provided with a downwardly extending projection which is disposed between the converging ramps, the projection being received within a recess formed in the brake shoe, the recess being of greater width than the projection.