Abstract: A hydraulic system (20) for controlling the seed/fertilizer supply system (10) and the down pressure on a plurality of individual row units (12). A secondary supply arrangement (60) interconnects a first control circuit (26) of supply system (10) with a second control circuit (28), when the row units (12) are in a float mode, to provide pressurized fluid for the down force on the row units (12) during operation.

Abstract: A ceiling-supported suspension mechanism for a piece of equipment, in particular for operating lights, has a pivot arm, as extension, which is arranged on the rotary bearing of a ceiling mount such that it can be rotated about a vertical axis. The pivot arm has two sub-arms which are connected to one another by an intermediate articulation which can be rotated about a vertical axis. The two sub-arms of the pivot arm are arranged at the same height such that they can be pivoted in a horizontal plane. The intermediate articulation can be pivoted merely in a limited angle range of up to 110°, as a result of internal stops. The sub-arm which is remote from the rotary articulation is provided, at its outer end, with an articulation which can likewise be rotated about a vertical axis and on which there is fastened a carrying arm for the suspension mechanism. It is possible for the carrying arm to be pivoted through 360°.

Abstract: A surface engaging implement having a surface penetrating member, a depth regulation member, a pressure sensor, a processor, and a variable controllable downpressure source is disclosed. The pressure sensor is disposed to detect loads upon the depth regulation member and to communicate load information to the processor. Through the processor, the controllable downpressure source may dynamically alter the pressure applied through the depth control structure to cause a desired excess downpressure and prevent an undesirably large or small amount of downpressure upon the depth regulation member. In this manner, a generally desired amount of excess downpressure may be dynamically maintained to maintain the ground penetrating member at a generally desired penetration depth.

Abstract: Method and apparatus for controlling the attitude of an agricultural implement drawn by an agricultural tractor, the device including a lift; two deflection sensors located at the attachment points of the bottom arms of the lift to the frame of the agricultural tractor; and an electronic central control unit for processing data received from the sensors and controlling lifting and lowering of the implement by the lift as a function of the data detected by the two sensors; the device being characterised in that each of the sensors has a locking device for adjusting the position of each of the sensors with respect to the frame so that each of the sensors assumes a predetermined tilt with respect to the ground.

Abstract: Method and apparatus for controlling the attitude of an agricultural implement drawn by an agricultural tractor, the device including a lift; two deflection sensors located at the attachment points of the bottom arms of the lift to the frame of the agricultural tractor; and an electronic central control unit for processing data received from the sensors and controlling lifting and lowering of the implement by the lift as a function of the data detected by the two sensors; the device being characterised in that each of the sensors has locking means for adjusting the position of each of the sensors with respect to the frame so that each of the sensors assumes a predetermined tilt with respect to the ground.

Abstract: An agricultural implement, having ground engaging tools mounted on subframes that are movable through hydraulic actuators between raised transport and lowered working positions, is provided with a hydraulic circuit in which the actuators are connected in parallel with one another within a grouping of the actuators. The positioning of the ground engaging tools into a lowered working position closes the hydraulic circuit for the group of actuators. The subframes are arranged to float over ground undulations to maintain a common working depth for the ground engaging tools. The vertical movement of any one of the actuators in the common group will force a displacement of a corresponding amount of hydraulic fluid, which will then be shared by all of the remaining actuators in the corresponding group. A depth averaging control for the ground engaging tools and a mechanical headland stop apparatus are also provided for the agricultural implement.

Abstract: The present invention provides a method and apparatus for controlling a work implement in order to enable an earth moving machine to move to a service area after a failure within an implement control system occurs. The method includes the steps of detecting the failure of the implement control system, enabling a limp home mode in response to the failure, and controlling the implement into a limp home position through operator interaction using a display and either an associated keypad or a touch screen.

Abstract: An apparatus for controlling a lateral position of a first member on a hitch of a work machine. A first processing device receives a first signal indicative of a desired turn radius of the work machine and transmits a first desired hitch position as a function of the first signal. A second processing device receives a second signal indicative of an actual hitch position and also receives the first desired hitch position. The second processing device transmits a first error as a function of the second signal and the desired hitch position. A controller receives the first error and transmits a second error as a function of the first error. A first member modulator receives the first error and transmits a first activation signal as a function of the second error. The first activation signal controls the lateral position of the first member.

Abstract: An ultrasonic transducer position sensor for use as part of an automatic depth control system. The ultrasonic transducer position sensor works with a Console and remote Controller mounted in the tractor cab, power beyond Valving, and Depth Sensors, either ground contact or non-ground contact, mounted on the frame of the implement. The depth sensing system is provided to sense the actual penetration of an implement tool by determining the height of the implement frame above the ground.

Abstract: An automatic depth control system is disclosed. The system includes a Console and remote Controller mounted in the tractor cab, power beyond Valving, and Depth Sensors, either ground contact or non-ground contact, mounted on the frame of the implement. The depth sensing system is provided to sense the actual penetration of an implement tool by determining the height of the implement frame above the ground. A circuit system is provided to receive the depth signal and to signal power beyond valving that will effect hydraulic corrections in order to maintain the select depth penetration. The Console includes an instrument panel having a toggle switch with AUTO, LOCK and MANUAL positions, an LED showing depth of tool penetration and a bargraph depicting variations from a desired depth and flashing lights on the bargraph to show depth corrections in process. The Console also includes a depth window in which no hydraulic correction would be made, a sensitivity switch, depth sensor switches and an UP/REPHASE switch.

Abstract: An arrangement for controlling the height above or depth below an irregular surface of a body moving over or below the surface includes a rotation sensor coupled to a controller responsive to an angular deflection signal output by the rotation sensor. The rotation sensor and controller are mounted to a vehicle moving over the surface such as an agricultural vehicle traversing a field. A semi-rigid, flexible arm has a first end coupled to the rotation sensor with a ground engaging member attached to a second opposed end of the arm. In one embodiment, the flexible arm includes an elongated coil spring attached to a rigid shaft and the ground engaging member is a spherical ball attached to the shaft's distal end. The coil spring is pre-loaded to a selected bending or flexure force and permits the ground engaging member to impact obstructions in the field without damage to the rotation sensor. The coil spring also prevents damage to the rotation sensor when the vehicle is reversed in direction.

Abstract: An automatic depth control system is disclosed. The system includes a Console and remote Controller mounted in the tractor cab, power beyond Valving, and Depth Sensors, either ground contact or non-ground contact, mounted on the frame of the implement. The depth sensing system is provided to sense the actual penetration of an implement tool by determining the height of the implement frame above the ground. A circuit system is provided to receive the depth signal and to signal power beyond valving that will effect hydraulic corrections in order to maintain the select depth penetration. The Console includes an instrument panel having a toggle switch with AUTO, LOCK and MANUAL positions, an LED showing depth of tool penetration and a bargraph depicting variations from a desired depth and flashing lights on the bargraph to show depth corrections in process. The Console also includes a depth window in which no hydraulic correction would be made, a sensitivity switch, depth sensor switches and an UP/REPHASE switch.

Abstract: A device for the control and adjustment of hydraulic cylinders on work attachments and assemblies of work machines, preferably self-propelled harvesting machines. Increasing the performance of harvesting machines for bringing in crops efficiently and without loss requires rapid, uncomplicated adaptation of the harvesting machines and front harvesting attachments to the respective load and operating conditions. The front harvesting attachments and wheel carriages are connected to the hydraulic circuit of the harvesting machine and driven automatically by means of the electronic control system as a function of the respective working and operating conditions.

Abstract: An apparatus and method is disclosed for positioning a farming implement connected to a farm work vehicle controlled by an operator. The apparatus includes an actuation system for positioning the implement with respect to a reference, a position sensor for providing a position signal indicative of the position of the implement above the reference, and an electronic control unit for receiving the position signal. The electronic control unit is operatively connected to the actuation system, and directs the actuation system to stop the implement if a predetermined period of time has elapsed after the position signal indicates that the implement has reached a predetermined position. An apparatus and method is also disclosed for positioning one or more markers associated with a farming implement connected to a farm work vehicle controlled by an operator.

Abstract: A control system controls the actuation of a plurality of control devices of a utility vehicle, including a PTO shaft control device. The control system includes a control unit which is electrically connected to the control devices and to switches for the manual actuation of the control devices. One of the switches is an automatic mode switch which controls activation of an automatic mode wherein the control unit automatically controls the control devices. In response to signals from a hitch switch, the control system transmits control signals to a hitch control which controls raising and lowering of an implement hitch. When the automatic mode is activated the control unit automatically disengages the PTO shaft if the hitch is raised above a pre-set hitch position.

Abstract: A control system for a hitched or trailed implement coupled to a work vehicle is disclosed herein. The control system allows control to be selectively transferred between various types of implements by use of a hydraulic selector valve. An electronic control unit controls the actions of a hitch assembly actuator, a trailed implement, an auxiliary device, or some combination thereof as determined by the configuration of the hydraulic selector valve.

Abstract: A potentiometer-based gauge wheel position sensor system for use as part of an automatic depth control system. The potentiometer-based gauge wheel position sensor system works with a Console and remote Controller mounted in the tractor cab, power beyond Valving, and Depth Sensors, either ground contact or non-ground contact, mounted on the frame of the implement. The depth sensing system is provided to sense the actual penetration of an implement tool by determining the height of the implement frame above the ground. The gauge wheel system comprises an inverted pyramid structure having a horizontal support member coupled to the implement frame. At one end of the horizontal support member, a compressible vertical support member is coupled between a wheel and the horizontal support member. At the other end of the horizontal support member, a wheel leg extension is coupled between the wheel and the horizontal support member.

Abstract: An irrigation control system including an irrigation controller, a portable data shuttle, and a personal computer. The user creates a watering program comprising watering schedules by using a graphical user-friendly interface of the personal computer. The watering program is then downloaded into the portable data shuttle. The portable data shuttle is coupled to an irrigation controller and a first watering schedule is downloaded from the portable data shuttle into the irrigation controller in a matter of seconds. At a later time, the data shuttle automatically downloads a second watering schedule replacing the first schedule, thereby updating the irrigation programming. For example, a new watering schedule may be automatically downloaded at preselected intervals to accommodate the changing seasons. The portable data shuttle includes voltage regulation circuits so that it can receive power from either the personal computer or the irrigation controller.

Abstract: A depth control system for controlling the working depth of an implement. The depth control system includes a monitor having an automatic mode of operation and a manual mode of operation wherein the automatic mode of operation provides preset, discrete working depth positions for the implement, and the manual mode of operation provides a continuous range of selectable positions. The monitor receives input signals from a position sensor mounted to the frame of the implement, and the position sensor includes a movable arm in sliding contact with an actuator arm mounted to a rock shaft of the implement whereby movement of the rock shaft and actuator arm causes the movable arm of the position sensor to move and provide different input signals to the monitor corresponding to the different positions of the rock shaft. The monitor provides an output signal to a hydraulic valve for controlling one or more hydraulic cylinders which actuate the rock shaft in movement to position the working depth of the implement.

Abstract: A slope excavation control system for a hydraulic excavator and a slope excavation method using a hydraulic excavator include an external reference 80 which extends horizontally in the direction of advance of a target slope face. A vertical distance hry and a horizontal distance hrx from the external reference to a reference point on a target slope face, and an angle of the target slope face are set by using a setting device. When a front reference provided at a bucket end is aligned with the external reference and an external reference setting switch is depressed, a control unit calculates a vertical distance hfy and a horizontal distance hfx from a body center of the excavator to the external reference, then calculates a vertical distance hsy and a horizontal distance hsx from the body center to the reference point of the target slope face by using the distances hsy and hsx as modification values.

Abstract: Detecting section detects joint angles and the relative angle of rotation from a plurality of rotatable operating tools mounted on a single mobile platform of a construction machine. Interference distance calculator, having recorded predetermined point positions for each operating tool, derives the distances between the plurality of operating tools on the basis of the detection results and the point positions, and calculates the shortest approach distance from these distances. If this shortest approach distance is less than a prescribed set distance, anti-interference controller issues a warning to alarm via the output controller, and it outputs anti-interference control to hydraulic control section CC such that the approaching tool is halted or slowed down, or the velocity of the operating tool being approached is matched to that of the approaching tool depending on the set mode.

Abstract: A control apparatus for a hydraulic excavator is capable of carrying out precise operations according to various kinds of classifications of works without requiring switching operations by an operator and management according to work records. The apparatus includes a classification of work discriminating section for recognizing a classification of work being carried out by the hydraulic excavator on the basis of data detected by sensors for detecting an operating amount of a lever for a boom and the like; sections for setting an operating mode of hydraulic pumps absorbing horse power and the like, according to the classification of work recognized; a hydraulic pump control section for controlling the hydraulic pumps according to the set operating mode; and an auto acceleration control section for making effective or invalid the auto acceleration control for controlling speed of an engine to a low speed when work stops.

Abstract: In the field of agricultural tillage, there is a need for accurate, automated control of the widths of tilling implements, such as ploughs. The invention concerns methods of controlling a plough operatively combined with a vehicle such as a tractor, the methods including logging a series of values of the strength of soil encountered during a pass along a field; selecting the most frequently occurring soil strength value; and, for a subsequent pass of the tractor/plough combination along the field in the same direction, setting the width of the plough in dependence on the most frequently logged soil strength value. A microprocessor is provided to carry out the methods of the invention.

Abstract: A mounting device for mounting non-contacting distance sensors to a variable-height implement of a paver or other construction vehicle is disclosed. The mounting device includes two extension arm assemblies, each extension arm assembly having an inner section and an outer section that are movable relative to each other, with the inner section being mounted to the variable-height implement. The mounting device further includes a beam assembly attached to the outer sections of the extension arm assemblies. The beam assembly includes a beam and mounting brackets for attaching a plurality of non-contacting distance sensors to the beam.

Abstract: An apparatus and method for controlling a hydraulically operated construction machine having a plurality of tandem articulated members which move in a particular pattern, wherein movement of one of the articulated members is controlled in response to movement of a second one of the articulated members. Anticipated future movement of the second articulated member is determined and the first articulated member is controlled as a function at least of the anticipated future movement of the second articulated member. Anticipated future movement is determined by measuring actual delay between movement of the first and second articulated members. Operation of the articulated members is a function of operation of an actuator and a selectable command level.

Abstract: A multi-product applicating system, seed planting system and control are provided for the dispensing of liquid or granular products in pre-selected amounts and planting seeds at pre-selected depths and frequencies. Three or more separate products can be dispensed simultaneously and constant control and monitoring of all products is provided for at the control console. Seed planting depth can also be continuously monitored. The present invention further provides a grid recipe system for creating a recipe which defines the amounts of each type of product to be applied to specific areas of the field and/or which defines a seed planting depths and frequencies for specific areas of the field. The grid recipe system utilizes the GPS and a data card having the recipe and/or seed depth/frequency stored thereon for controlling a computer which communicates with the control console of the present invention. The recipe and/or depth/frequency grid is created by the farmer based on personal knowledge and experience.

Abstract: A control system for engaging, disengaging and re-engaging a front wheel drive in an agricultural vehicle includes a control circuit configured to receive signals representative of vehicle operating parameters and to generate control signals corresponding to the desired state (i.e. engaged or disengaged) of a front wheel drive engagement circuit. Sensors are associated with the rear wheels, rear service brakes, implement positioning circuit, the vehicle body and the front axle to provide parameter signals related to wheel speed, braking, implement position and vehicle speed. Control logic executed by the control circuit in a continuously cycled routine determines the desired state of the engagement circuit based upon all operating parameters. The control circuit applies an appropriate control signal to the engagement circuit causing engagement or disengagement in accordance with the desired state.

Abstract: A self-leveling system for a multi-purpose vehicle used primarily for off the road operations such as roadside mowing. The vehicle frame and operator's station will automatically remain substantially level on sidehills, and if a slope greater than a predetermined amount is encountered, the operator will be given a warning signal which, if ignored, will result in the shut-down of the vehicle's operating system and the vehicle will stop. If the operator chooses, the vehicle can be operated from a remote location after the warning signal is received.

Abstract: An agricultural planter comprises a frame with a plurality of wheels and adapted to be towed by a tractor. The planter has a plurality of row planting units mounted on the frame and carrying planting implements, and the planting units are vertically movable relative to the frame. A soil-hardness sensing unit carried on the frame produces a signal representing the hardness of the soil. A controllable biasing device is connected to the planting units for adjusting the force applied to the soil by the planting units, in response to the signal representing the hardness of the soil.

Abstract: In an excavation area limiting control system for a construction machine for limitingly controlling an area to be excavated, a region where a front device 1A is movable is set beforehand. The position and posture of the front device are calculated based on signals from angle sensors 8a-8c, and a target speed vector of the front device is calculated based on detection signals from control lever units and load pressures detected by pressure sensors 270a to 271b. The target speed vector is modified so that a vector component of the target speed vector in the direction toward the boundary of the set region is reduced when the front device is within the set region near the boundary thereof, and the front device is returned to the set region when the front device is outside the set region. Control signals corresponding to the modified target speed vector are further modified depending on the load pressures and output to proportional solenoid valves 210a to 211b.

Abstract: A control system for regulating the elevational position of an implement carried or trailed by a vehicle, such as a tractor, includes draft force sensors for detecting the draft force produced by interaction of the implement with the ground, and a command device for setting a reference level of draft force. A control circuit coupled to the sensors and to the command device generates a draft force error signal representing the deviation of the sensed draft force from the desired level, and a draft force derivative signal representing the rate of change of the sensed draft force. The control circuit generates control signals for raising and lowering the implement following a predetermined control routine in response at least to the draft error signals. The rate of movement of the implement in response to the control signals is limited in response to the draft force error signal and the draft derivative signal.

Abstract: The zone tillage coulters on a drilling or planting implement are maintained at an essentially constant running depth by control apparatus that includes a programmed microprocessor-based controller and a hydraulic operating system that receives commands from the controller based upon inputs received from various sensors. One such sensor comprises a ground wheel which rides along the ground and swings up or down as changes in the terrain are encountered, such motions thus imparting voltage inputs to the controller which compares such inputs with previously selected data inputted by the operator. If the comparison results in a sufficiently large difference between the operator-selected data and the actual data coming from the sensor, the controller will cause a tongue cylinder to be actuated in the appropriate direction to buckle the tongue about a horizontal axis and thus either raise or lower the tongue and coulter gangs fastened thereto.

Abstract: A hydraulic drive system for the pitch cylinders (4A, 4B) of a bulldozer blade apparatus can include (a) main hydraulic pumps (30A, 30B) and an assistant hydraulic pump (31) to make up the assistant hydraulic circuit, (b) variable displacement hydraulic pumps (21A, 21B), or (c) fixed displacement hydraulic pumps (30A, 30B) and a plurality of solenoid selector valves such that the pitch cylinders can be connected in series. The assistant hydraulic pump (31) is connectable to delivery lines of the main hydraulic pumps through an assistant solenoid selector valve (32) which is controlled by an external signal. The blade (10) can be formed so that a line (14) tangential to the lower edge of the curved panel of the blade is inclined rearwardly with respect to the front face (13) of the blade edge member (12). Earth-moving work can be performed by inclining the blade (10) rearwardly by an angle (.theta..sub.

Abstract: A cultivating system including a tractor, a cultivating machine for performing a cultivating work in combination with the tractor, and a link mechanism for linking the tractor and the cultivating machine, includes a free-motion mechanism provided to at least one of the tractor, the cultivating machine and the link mechanism, and having a free motion permissible zone in which at least one of the tractor, the cultivating machine and the link mechanism is freely movable relatively to the others in accordance with variation of a cultivation attitude of the cultivating machine due to variation of a cultivation environment, a cultivation-condition control mechanism for detecting the free motion of at least one of the tractor, the cultivating machine and the link mechanism within the free motion permissible zone in accordance with the variation of the cultivation environment, and moving the cultivating machine in accordance with the free motion permissible zone so as to offset the variation of the attitude of said c

Abstract: An apparatus and method for controlling a hydraulically operated construction machine, having a plurality of tandem articulated members which are controlled in a manner that movement of one of the members is controlled in response to movement of another of the members, in order to move the members in a predetermined pattern. The members are controlled in response to the anticipated future movement of the another member. Anticipated future movement of the another member may be determined, for example, as a function of the present position and velocity of the another member and system delay in movement of the another member. Where the another member is controlled manually by an operator control lever coupled with a manual hydraulic control valve, anticipated future movement may be determined by monitoring actuation of the control lever.

Abstract: A hydraulic downpressure system for use on no-tillage seeders allows for a constant downward force to be applied on seeding tools operating in highly variable soil surface conditions in order to keep a uniform seeding or planting depth. Raising and lowering of the seeding units can also be achieved with this hydraulic system. A double acting hydraulic cylinder is principally used having its rod end connected to one or two seeding units. A hydraulically operated two-way mode selection valve provides system shifting between both modes involved. The first mode is used when transporting the seeder on roads and to operate the seeding tools in the field. Control is then provided by a three-way directional valve mounted to an external hydraulic power supply, such as an agricultural tractor. Raising and lowering of the seeding tools can be achieved when operating in this mode. A second mode is involved when the seeding tools are working into the ground to sow seeds.

Abstract: A control system controls a plurality of control devices (such as a four wheel drive control valve, a differential lock control valve and a PTO control valve) of a work vehicle having an implement hitch coupled to a hitch actuator which is controlled by a hitch control unit. The control system has operating switches for adjusting the operation modes of the control devices and the hitch actuator. The control unit also has means for activating and deactivating an automatic mode for the control devices in response to manipulation of a first switch and means for activating the automatic mode upon a manual operation signal delivered to the hitch control unit to change the operation modes of the functions of the control devices. The control system includes an automatic switch which is manipulatable independent from the other switches. A sensor senses the position of the hitch.

Abstract: A hitch assembly control system including an actuator which positions the hitch assembly in response to control signals provided to an electrically driven actuator. The control system further includes an electronic controller operated under the influence of a program for deriving the control signals for the actuator from a series of inputs which monitor and measure various performance criteria. The program functions to operate the hitch assembly in a plurality of different operating states. In a DRAFT state, the hitch assembly position is controlled under the influence of at least four independently set variables. The control system of the present invention is capable of calibrating the hitch assembly configuration as well, as the limits of hitch assembly operation. Moreover, the control system of the present invention is capable of detecting, categorizing and recording failures which occur in various states of hitch assembly operation.

Abstract: A system for maintaining the depth of a planter (or tiller) at a soil depth of optimal moisture content is provided, in which a prior art soil resistivity sensor is improved by including a negative electrode immediately behind the prior art positive electrode as the planter and electrodes extend into the ground during tractor travel over the field. The prior art positive probe is shaped to form a compact ribbon of soil therebeneath that extends from the positive to the new negative probe. This compact ribbon provides a reliable and consistent path for measuring soil resistivity at a soil zone of least electrical resistance, thereby preventing other pathways between the positive electrode and grounded parts of the planter or tiller from undesirably entering the detection system in lieu of the desired pathway of measurement.

Abstract: A soil treating system having a frame, a first implement to engage soil to effect treatment thereof and mounted to the frame in an operative position in which the implement can be moved vertically relative to the frame, and an hydraulic actuator acting between the frame and implement for exerting a variable downward force on the implement.

Abstract: An apparatus for generating a signal indicative of the hardness of soil. The apparatus has a frame to be moved relative to soil on which a hardness analysis is to be conducted and a sensing element mounted to the frame so that the sensing element engages soil relative to which the frame is moved and structure associated therewith generates a) a first signal as the sensing element encounters soil of a first hardness and b) a second signal as the sensing element encounters soil of a second hardness.

Abstract: A hitch assembly control system is provided in which signals representative of battery voltage are used to generate a correction factor that is applied to control signals to a hitch actuator circuit to improve consistency in control. In an alternative embodiment, a correction factor is generated from signals representative of electrical parameters of solenoid coils included in the actuator circuit and this correction factor is applied to control signals to the actuator circuit. Also provided is a calibration method for a vehicle control system in which certain physical and electrical parameters of the vehicle and the control system are measured and stored during a calibration sequence for later use in the control of an implement coupled to an attachment member of the vehicle. A control method for a vehicle is also provided in which correction factors are generated from measurements of battery voltage or a solenoid coil parameter, and applied to control signals generated by a control circuit.

Abstract: A hitch assembly control system including an actuator which positions the hitch assembly in response to control signals provided to an electrically driven actuator. The control system further includes an electronic controller operated under the influence of a program for deriving the control signals for the actuator from a series of inputs which monitor and measure various performance criteria. The program functions to operate the hitch assembly in a plurality of different operating states. In a DRAFT state, the hitch assembly position is controlled under the influence of at least four independently set variables. The control system of the present invention is capable of calibrating the hitch assembly configuration as well, as the limits of hitch assembly operation. Moreover, the control system of the present invention is capable of detecting, categorizing and recording failures which occur in the various states of hitch assembly operation.

Abstract: A one-way pressure bleed off path is provided between the series cylinder depth control circuit and an additional hydraulic circuit for an agricultural implement to prevent pressure build-up and hose expansion that otherwise would cause uneven series cylinder extension and uneven implement depth. A line including an orifice and a one-way check valve is added between the depth control circuit and the second circuit, such as the wing fold circuit for the implement, to bleed off any series cylinder pressure build-up through the otherwise unused second circuit. The orifice limits the amount of oil that is returned to reservoir during operation of the series circuit to lower the implement. The check valve isolates the depth control circuit and the second circuit to prevent unwanted cylinder operation while the wings are being folded.

Abstract: A hitch assembly control system including an actuator which positions the hitch assembly in response to control signals provided to an electrically driven actuator. The control system further includes an electronic controller operated under the influence of a program for deriving the control signals for the actuator from a series of inputs which monitor and measure various performance criteria. The program functions to operate the hitch assembly in a plurality of different operating states. In a DRAFT state, the hitch assembly position is controlled under the influence of at least four independently set variables. The control system of the present invention is capable of calibrating the hitch assembly configuration as well, as the limits of hitch assembly operation. Moreover, the control system of the present invention is capable of detecting, categorizing and recording failures which occur in the various states of hitch assembly operation.

Abstract: A load control device applicable on agricultural machinery in general and in particular on machinery used for direct planting, so that the working components in contact with the ground will maintain the same load constantly at all times for any ground profile condition. An oil-pneumatic device is provided with a fluid compressor connectable to the tractor's power take-off by a cardan shaft and an electromagnetic clutch that can be powered from the tractor's electrical system or by an independent source, including a compressor with its associated pressurestat which governs it in order to maintain the air pressure required by the circuit. The compressor supplies a tank of compressed air, to which is connected at least one hydraulic cylinder whose upper and lower chambers are each connected to intermediate air and oil collecting reservoirs.

Abstract: A feedback mechanism for providing an implement position signal includes a rotary potentiometer mounted on the implement frame adjacent the rockshaft with the axis of the potentiometer shaft extending parallel to the rockshaft. A linkage structure includes a potentiometer arm connected to a rockshaft arm by a link such that the angle the potentiometer arm forms with the link is acute when the implement is in the transport position and obtuse when the implement is in the lowered field-working range. At the lowermost position of the implement, the link and potentiometer arm approach an overcenter position. The linkage structure provides amplified rotation of the potentiometer shaft relative to the rockshaft when the implement is in the field-working range of positions, while rotation of the shaft is reduced relative to rockshaft rotation when the implement is raised above the field-working position. In the preferred embodiment, rotation of the rockshaft 10.degree.

Abstract: A chain is connected at its distal end to the pin at the rod end of a cylinder on an implement lift and depth control assembly. An intermediate portion of the chain is trained around a gear which rotates about the axis of the pin connecting the base end of the cylinder to the implement frame. An adjustable length, spring-biased rod is connected to the proximal end of the chain to maintain tension in the chain and operate a single point depth control valve to establish a highly accurate and repeatable depth setting which is dependent directly on cylinder rod extension and therefore less susceptible to looseness in the implement lift system.

Abstract: A control system for the co-ordination of the operation of first and second implements mounted at spaced locations relative to the intended direction of travel of a tractor vehicle. The system can be used to co-ordinate the operation of spaced parts of a larger common implement (e.g. spaced shares on a long plough) or completely separate implements (e.g. ploughs mounted one on the front and the other on the rear of the tractor vehicle). The control system includes actuators for controlling the operation of the first and second implements, a speed sensor for sensing the forward speed of the tractor/implement combination, sensors to indicate the operating condition of the implements and an implement spacing compensation means which allows adjustment of the co-ordination of the operation of the implements dependent on the spacing between the implements.

Abstract: A method and apparatus for automatically controlling the depth of earth grading for utilization with a grader or paver is disclosed. The method includes determination of time taken for an acoustic pulse to travel from a transducer to a reference surface and back, with this value being used to calibrate a microprocessor-controlled distance-measuring device. As the grader moves over a surface to be graded, the distance to the reference surface is constantly detected by a repeated emission and detection of such acoustic pulses. The timing of the echoed pulses is converted to addresses in a look-up table which contains control words symbolizing commands to be given to hydraulic rams carried by the grader. By implementing these commands, the depth of the blade relative to the reference surface is constantly updated, compensating for variations with the height of the reference surface. A thermistor is provided to automatically compensate for temperature variations as the grading takes place.