Abstract: Clutch-brake steering unit having hydraulically actuated cylinders for controlling same to control rotation of a track-drive sprocket in a crawler tractor. Specifically a clutch cylinder and a brake cylinder provided in the unit have an inlet-outlet port in common, and are so arranged on a spring-applied-brake, hydraulically-applied-clutch basis that a single pressure signal in the inlet-outlet port alternately operates the cylinders to apply the brake and release the clutch, to apply the clutch and release the brake, or by proper modulation to partially engage either, i.e., slip the clutch or drag the brake to intermediate degrees as desired.

Abstract: A boom assembly for a loader that is pivotally mounted on a tractor. The assembly includes a pair of boom arms which are pivotally connected at one end of the tractor. The arms are fabricated from two C-channels which are welded together. The arms have aligned inside apertures sized to accept a cross tie member which is rigidly connected to both channels.

Abstract: An economical and effective auxiliary steering system for a vehicle having a relatively low maximum speed in reverse direction. A ground driven pump having an output when the vehicle is going forward is directed to a diverter valve, which valve is responsive to loss of hydraulic pressure in the main steering circuit to direct the said output to the main steering valve. A single spring loaded check valve isolates the main steering valve under auxiliary steering conditions.

Abstract: Transmission having a number of lubricant cooled friction engaging means, a majority of which at any time are nonselected for operation, and further having flow blocking sleeves individual to the friction engaging means, each providing a friction coupling in the power path for shift purposes. Valve means is provided therein to direct coolant flow at lo rate to each friction coupling when such coupling is not engaged, and to increase flow to hi rate thereto when it is engaged.

Abstract: A boom assembly for a loader that is pivotally mounted on a tractor. The assembly includes a pair of boom arms which are pivotally connected at one end of the tractor. The arms are fabricated from two C-channels which are welded together. The arms have aligned inside apertures sized to accept a tube which is rigidly connected to both channels. The assembly is completed when a cross tie member envelopes the tubes and is rigidly secured to the inner C-channels.

Abstract: A loader bucket is provided with a plurality of leaf springs appended to the bucket for interaction with the bucket support linkage. The leaf springs impose forces on the bucket link pins preventing undesirable movement between the bucket and the support linkage when the bucket is rolled into a load transporting position.

Abstract: A valve assembly is provided in which a first poppet member and at least one subsequent poppet member each having a valve face engageable with a valve seat between first and second passages. A first and a subsequent pilot valve is operative for selectively establishing communication between a fluid reservoir and a space at one side of a piston portion of each poppet member and a pair of restricted flow passages are provided in each poppet member between such space and the first and second passages, such restricted flow passages being preferably formed in the poppet members with ball check valves provided therein. Such restricted flow passages operate upon closure of the pilot valve to develop a static pressure in the space corresponding to the pressure in the one of the first and second passage which has the higher pressure therein so as to move the poppet member to and hold it in its closed position in response to pressures applied from either of the first and second passages.

Abstract: An operator's platform, a vehicle cab and a forward tractor engine enclosure are pivotally mounted as a unit at a forward pivot point to a tractor frame. These components are suspended at the rear portion of the frame through an integrated suspension system including a coil spring and a shock absorber. A pair of stationary vertical guide members at the rear of the vehicle interact with adjacent wall guide surfaces of the suspended chassis. These stationary vertical guide surfaces allow the suspended chassis to pivot in a vertical plane around the forward pivot points while controlling lateral movement of the cab relative to the vehicle chassis.

Abstract: An unloading valve spool with a tapered nose section is urged across a pair of unloading ports at a controlled rate eliminating violent upstream pressure generation. The unloading valve is subjected to equal system fluid pressure on each side of it as the spool is provided with a through passage that is dead headed on the back side of the unloading spool. A return spring urges the unloading spool to a normally closed position. An unloading piston prevents the unloading spool from closing too rapidly preventing the generation of a significant upstream pressure spike.

Abstract: An operator's platform, a vehicle cab and a forward tractor engine enclosure are pivotally mounted as a unit at a forward pivot point to a tractor frame. These components are suspended at the rear portion of the frame through an integrated suspension system including a coil spring and a shock absorber. A pair of vertical guide members at the rear of the suspended chassis of the vehicle interact with rollers accompanied on laterally projecting arms fastened to the rear section of a tractor chassis to pivot in a vertical plane around forward pivot points while constraining lateral movement of the cab relative to the vehicle chassis.

Abstract: A hydraulic follow-up for use with a hydraulic system placed between a rotating input member and a rotating output member. The hydraulic system is a hydrostatic transmission for driving a tractor, and comprises a hydrostatic pump and a hydrostatic motor driven by the pump. When the hydrostatic pump is angularly shifted with respect to the input member, the shifting is controlled by the hydraulic follow-up, which also shifts the motor in relation to the output member.

Abstract: The operational speed of a fluid drive unit in a hydromechanical transmission is limited by means of an overspeed preventing, one-way clutch establishing a positive drive connection between torque transmitting elements of the hydromechanical transmission. Two power paths are established between the planetary gear unit and the input shaft of the transmission to drive an output shaft at a variable drive ratio controlled by a variable displacement type of fluid drive unit. One of the power paths is established through fixed ratio gearing while the other power path is established through the fluid drive units while operating within a speed ratio range limited by the one-way clutch.

Abstract: Hydraulic controls in a transmission for engaging a clutch for the F-R, or forward or reverse, direction before a clutch for first, second, or third speed. Flow of hydraulic fluid to each direction clutch and to each speed clutch is by way of a reducing valve which modulates fluid pressure in controlled way by throttling the flow. After the power unit for the clutch for the F-R clutches and the power unit for the clutch for first, second or third speed are filled with fluid by the reducing valve, pressure in the power units is then slowly raised by the valve linearly toward its maximum; for this purpose the hydraulic controls are supplied by a single source of hydraulic fluid and operate therefrom to provide a pair of modulated pressure outputs which are maintained with varying differences throughout their range of operation, and which operate the selected one of the F-R clutches and the selected one of the first second or third clutches.

Abstract: A multi-functioning hydraulic transmission control circuit including interacting valve mechanism parts which, in response to a shift being called for in a clutch-cylinder-controlled multi-speed transmission, inaugurate a fill pressure flow to the clutch cylinders concerned, prior to the subsequent fluid pressure rise effected therein; thereafter, upon completion of the fill, the parts modulate pressure rise of the hydraulic clutch fluid from and at approximately actual clutch fill pressure up to, and remaining at, the final pressure of engagement.

Abstract: Transmission having a number of lubricant cooled friction engaging means, a majority of which at any time are nonselected for operation, and further having flow blocking sleeves individual to the friction engaging means, each providing a friction coupling in the power path for shift purposes. Means is provided therein to direct coolant flow at lo rate to each friction coupling when such coupling is not engaged, and to increase flow to hi rate thereto when it is engaged.

Abstract: A control system is provided for a hydraulically operated tractor hitch assembly including a rockshaft operated by a main cylinder which is controlled through a spool valve operated by a pilot cylinder which is controlled, in turn, through a solenoid operated pilot valve. The pilot valve is selectively controlled from first and second detector circuits through a gating circuit which is controlled by a third detector circuit which responds to a first error signal developed by comparing a command signal which corresponds to a rockshaft target position and a first feedback signal which corresponds to the actual rockshaft position and which is generated by a potentiometer connected to the rockshaft.

Abstract: A control system is provided for a hydraulically operated tractor hitch assembly including a rockshaft operated by a main cylinder which is controlled through a spool valve operated by a pilot cylinder which is controlled, in turn, through a solenoid operated pilot valve. The pilot valve is controlled in response to a command signal and first and second feedback signals which correspond to the position of the rockshaft and to the position of the spool valve member. The velocity of the downward movement is limited by limiting the amplitude of a first error signal which is developed by a first comparator responsive to the command and first feedback signals with the first error signal and the second feedback signal being applied to a second comparator. Such velocity-limiting operations are controlled through a manually operated switch or by a motion sense circuit responsive to the rate of change of the command signal.

Abstract: A multi-functioning hydraulic transmission control circuit including interacting valve mechanism parts which, in response to a shift being called for in a clutch-cylinder-controlled multi-speed transmission, inaugurate a fill pressure flow to the clutch cylinders concerned, prior to the subsequent fluid pressure rise effected therein; thereafter, upon completion of the fill, the parts modulate pressure rise of the hydraulic clutch fluid from and at approximately actual clutch fill pressure up to, and remaining at, the final pressure of engagement.

Abstract: A pneumatic spacer and cushioning tire assembly, having an armored peripheral track fitted thereto is provided for use on construction and earthworking equipment. The track assembly has a belt of elastomer insulated inextensible filaments constrained between anchor plates and traction plates. The interior surface of the track assembly prevents movement between the track and the tire.

Abstract: A stowable ladder for use on a combine is provided with a spring assisted overcentering linkage that will maintain the foldable ladder in either a deployed status or closed status until significant manual effort overcoming the spring loaded overcentering linkage is induced.