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 metering mechanism comprises a housing (7) with a material inlet (12) and a rotary metering member (27) that is rotatably mounted between side walls (8,9) of the housing with its periphery exposed to a chamber (48) within the housing so as to meter material from the chamber as it rotates, characterized in that a removable insert (74) is provided that is a close fit in said chamber and has a passage (75) through it that communicates at one end with said inlet (12) and at the other end with the periphery of the rotary metering member (27) so that the effective volume of said chamber (48) is reduced to the volume of said passage (75). Thus, if the metering mechanism incorporates the known shutter-type tramlining device in which a shutter (24) serves to close the inlet (12) to the housing, the quantity of speed retained in the chamber within the housing is reduced and therefore the length of a bout that will be sown after closing the shutter will be correspondingly reduced.

Abstract: An extendable material handling arm which is particularly suitable for use as a dipper stick of a back hoe digger. The arm has an outer member with a slot extending along its length, and an inner member provided with a digging bucket pivotally mounted adjacent one end. The inner member is encircled by the outer member for sliding therein to vary the effective length of the arm. A first support structure carried by the inner member adjacent the end remote from the bucket includes a support plate with a support surface for sliding contact with longitudinally extending portions of the outer surface of the outer member adjacent the slot.

Abstract: A pedal actuator in which a pedal 10 is movable by the application of foot pressure between raised and depressed positions to actuate a device such as a vehicle differential lock 11 via an operating device 12,13,14,16. The pedal is biased towards its raised position, and a holding device 24 is provided for maintaining the pedal in its depressed position. The holding device comprises a cam follower 33 connected with the operating means for co-movement therewith and a cam 32 for co-operation with the follower. The cam includes a first cam path 34 along which the follower 33 is moved as the pedal is moved from its raised to its depressed position, a holding position 35 in which the cam follower is held by the bias 21 to hold the pedal it its depressed position, and a second cam path 36 along which the follower moves under the action of the bias as the pedal rises from its depressed position to its raised position.

Abstract: In a seed drill having tractor wheel track eradicators (13), coulters (1) that sow rows of seeds along the line of the tractor wheel tracks (T), and tramlining means (4,5) that serves to stop the supply of seed to said coulters (1) to form tramlines on selected bouts; said track eradicators (13) are lifted out of work when sowing a bout with tramlines so that the tractor wheel tracks (T) remain and form a mark along the unsown rows. Preferably, said coulters (1) are also lifted out of work with the track eradicators (13) so as to avoid disturbing the tractor wheel tracks unduly.

Abstract: An hydraulic unloading valve for unloading hydraulic fluid from a circuit pressurized by a diesel engine powered pump under cold climate conditions to assist starting of the engine. The valve has an inlet through which fluid enters the valve, an outlet through which fluid may leave the valve, an outlet valve seat, a valve member movable towards and away from the valve seat and carrying a valve surface for closing off the seat valve, a first orifice sensitive to viscosity which in response to the flow of fluid through the inlet generates a first pressure drop arranged to tend to move the valve member away from the valve seat, and second orifice which is not sensitive to viscosity and which in response to said flow generates a second pressure drop arranged to tend to move the valve towards the valve seat to bring the valve seat and surface into contact to close-off through the valve outlet when the second pressure drop is greater than the first pressure drop.

Abstract: A tractor power take-off drive line which includes a friction clutch (12) which is engaged by a fluid pressure operated actuator (12a) via a solenoid-operated valve (14). The engagement of the clutch is controlled by a system which includes a pulse width modulation function for providing a series of electrical pulses to the solenoid (14a) of the valve in successive predetermined time intervals during engagement of the clutch. Each pulse has an "on" period during which the valve connects the actuator to a source of pressurized fluid and an "off" period during which the valve connects the actuator to a dump line. Sensors (18,19) provide signals indicative of the input and output speeds of the clutch, and a micro processor control circuit (25) establish for successive time intervals the ratio between the intput and output speeds of the clutch and the change in this ratio by comparison with the ratio for a previous time interval.

Abstract: A vehicle performance monitoring apparatus (20) for displaying the values of a plurality of performance parameters of a vehicle (10). The apparatus includes sensors (21,22,23,24,25) for sensing data indicative of the performance of the vehicle, processing means (40,42) for processing this data to provide the parameter values, display means (35) for displaying said parameter values, and operator command means (37,38) for controlling the operation of the apparatus including the selection of which performance parameter is to be displayed on the display means and the initiation of processing routines by the processing means. Additionally the apparatus includes memory means (43,44,45) for storing performance information relating to the performance parameters and the processing means (40,42) is arranged in response to a predetermined operation of the operator command means (37,38) to store in the memory means (43,44,45) a performance parameter value for each of a number of so-called relative mode parameters.

Abstract: A hydraulic fluid supply assembly for an agricultural or industrial tractor or similar vehicle. The assembly includes a mounting plate which closes an aperture in a back axle casing of the vehicle and which carries a hydraulic pump, a pump feed means, and a filter which is mounted on a filter head formed integrally in the plate. The supply assembly is arranged to be demountable from the casing as a unit. The mounting plate also carries one or more hydraulic valves or other hydraulic consumers which receive fluid from the pump via supply passages formed integrally in the mounting plate and a gear wheel which engages with the vehicle drive train to provide drive to the pump when the mounting plate is secured in position over the aperture.

Abstract: A fluid pressure system incorporating a piston and cylinder actuator which is initially moved from right to left and is reversed at the left hand end of its stroke by a switching valve upon receiving a signal through a passage from a sensing valve which becomes hydraulically balanced during a no-flow condition of the system and is displaceable to a switch initiating state during that condition by a small force originating from a light spring, or the actuator or from the operation of another valve in the system.

Abstract: A clutch protection system to guard against overheating due to excessive slippage in a friction clutch (12). The system which is particularly suitable for use with a tractor power take-off clutch includes sensors (18, 19) to provide signals indicative of the input and output speeds of the clutch and an indicating device (56) which receives a first signal (I) indicative of the clutch input speed and a second signal (X) indicative of either the clutch output speed when the clutch engagement pressure is applied or the clutch input speed when the clutch engagement pressure is not applied. The indicating device has a signal level indicative of the difference between the first and second signals minus a signal indicative of the cooling effect on the clutch due to its own rotation.

Abstract: A disc for use as a rotor (10) or stator (18) in a multiple-disc brake. The disc (10) has an annular peripheral band (15) provided with a series of circumferentially spaced through slots (12) which open through a periphery of the disc. Each slot is defined by edges (13, 13a) which extend away from the periphery across the annular peripheral band (15) and are inclined in opposite directions (.alpha.) to a given radius (14) of the disc extending therebetween so that the slot tapers in a radial sense.A multiple disc brake is also provided which has a housing (46, 47) containing oil or other coolant which encloses a disc stack in the form of interleaved sets of rotor (10) and stator (18) discs.

Abstract: A method and apparatus for controlling a plurality of subsystems (66, 70) associated with an agricultural vehicle such as a tractor. Examples of such subsystems in a tractor are hitch positioning, power take off (PTO), multiple range transmissions, differential lock, diesel fuel injection, and the like.A unified control system is provided including a central control unit having a first microprocessor (56) and a plurality of subservient control units each having a microprocessor (58, 60). Each of the subservient control unit microprocessors (58, 60) are connected for controlling at least one subsystem (66, 70) and for sensing the operating conditions of at least a single subsystem (66, 70) using sensors (68, 72). The subservient control unit microprocessors (58, 60) are also connected to the central control unit microprocessor (56) which controls communication between the subservient control unit microprocessors (58, 60).

Abstract: A drive direction selection system for a vehicle transmission including a source of electrical power, a first circuit for supplying an electrical signal from the source to a forward drive direction engagement means and a second circuit for supplying an electrical signal from the source to a reverse drive direction engagement means. Forward and reverse drive direction selection pedals are provided which when depressed close forward and reverse direction selector switches in the first and second circuits respectively. First interlock means are arranged to break the first circuit on closing of the reverse direction selector switch and to maintain the first circuit broken until both switches are again simultaneously in their open condition. Second interlock means are arranged to break the second circuit on closing of the forward direction selector switch and to maintain the second circuit broken until both switches are again simultaneously in their open condition.

Abstract: A vehicle drive arrangement in which a drive shaft (10a) is coupled with a first hollow driven shaft (12) and a second driven shaft (11) within hollow driven shaft (12) by first (14) and second (13) coaxial clutches respectively clutch (13) which is adjacent flywheel (10) is operated by a force transmitting path in the form of pins (17) located outside both driven shafts and passing axially through the central portion (24) of clutch (14). This produces a more compact arrangement since the force transmitting path for the operation of clutch (13) does not pass around the outer periphery of clutch (14).

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 hitch in which a pair of lower implement attachment links (10) are stabilized by a pair of sway blocks (16) with rubbing surfaces (16a) which cooperate with the links or rubbing blocks (30) on the links to control the amount of sidesway of the links. Each sway block (16) is mounted adjacent its upper end on the tractor by a mounting device (17,18,19,20,21,24) which allows the block to pivot generally in a transverse plane relative to the tractor and adjustment devices (25,26,27,27',28) are provided at the lower end of each sway block to allow the angle of pivot of the block to be continuously adjusted to set the amount of permitted side sway of the links when the links contact the lower ends of the blocks. The spacing (X) between the rubbing surfaces (16a) at the upper ends of the sway block (16) is also adjustable and shock cushioning (31) may be included in the mounting device of the sway blocks to cushion the links against sideways loading arising from loads carried by the links.