Abstract: A method is disclosed for controlling the cutting depth and angle of an excavator bucket to excavate a surface to a desired contour. The method includes the steps of: (1) inputting data to a machine control system to define a desired contour of the excavated surface; (2) positioning the excavator bucket close to the desired contour; (3) enabling automatic control; and (4) automatically controlling movement of the excavator bucket only when the position of the excavator bucket is within a predetermined distance or angle of the desired contour. The method is used to automatically control the excavation to a desired depth if the bucket is within a predetermined distance of a desired depth. The method is also used to automatically control the angular orientation of bucket if the slope of the bucket is within a predetermined angle of a desired slope.

Abstract: Computer implemented methods for determining blocked and partially blocked conditions in the flow of particulate matter in an agricultural air seeding system are disclosed which automatically adapt for changes in seed type, seed density, fan rate or seed rate. In a first embodiment, the number of samples that are taken before making a determination of the blockage condition is varied depending on the number of seed events that have been detected in a given time interval. In a second embodiment, one or more criteria such as the maximum number of samples to wait for an event, the value a sensor filter must reach before the method determines a blockage sensor to be BLOCKED, or the value a sensor filter must reach when in the blocked state before the method determines the sensor is no longer blocked is varied depending on a smoothed value of the number of seed events that are detected per sampling period.

Abstract: In the process of the invention, the seed to be treated, a predetermined amount of solid matrix material and a predetermined amount of water are admixed and the mixture allowed to stand, preferably in a container which allows entry of air but which reduces evaporation losses, for example, a closed metal container with a small top opening, for a time and at a temperature sufficient to enhance resultant plant vigor, i.e., enhance emergence, growth of yield characteristics, but short of that which would cause the seed to sprout. Faulty seeds may be separated by size and systemic resistance to disease can be induced.

Abstract: A seed blockage monitoring system employs a flexible, generally flat piezoelectric seed sensor element inserted at an acute angle of about 13 degrees into a seed flow path so that a portion of seeds traveling in the seed flow path strike the seed sensor element, preventing damage to the seeds and maintaining forward momentum of all seeds in the seed flow path. In order to provide flexibility in monitoring seeds of different types and to increase the data rate that information can be obtained from numerous multiple seed sensor elements, the use of a one-shot to temporarily store a seed detection signal and serial sampling of the temporarily stored signals from the sensors as in the prior art is avoided. Instead, a comparator that includes a diode in a feedback loop so as to function as a latch is used in conjunction with a serial shift register that has parallel data input lines.

Abstract: A particle blockage monitoring system employs a flexible piezoelectric particle sensor element in a portion of a particle flow path so that a number of particles traveling in the particle flow path strike the flexible particle sensor element while preventing damage to the particles and maintaining the forward momentum of all the particles in the particle flow path. In order to provide flexibility in monitoring particles of different types and to increase the information rate, the use of a one-shot multivibrator to temporarily store a particle detection signal as in the prior art is avoided. Also, serial sampling of the particle sensor data is avoided to increase the information rate. Instead, a comparator that includes a diode in a feedback loop so as to function as a latch is used in conjunction with a serial shift register that has parallel data input lines.

Abstract: A method and circuit for determining whether a sensor 2 is attached to a connection point 5 of a sensor interface circuit 1 of a seed monitoring system. When it is desired to determine whether a sensor is attached to a connection point, the method applies a time varying detection signal at terminal 3 to the connection point 5 via a reactive element, such as capacitor 4. The connection point 5 is connected to a first input of a comparator 9 having its other input set at a first reference voltage which maintains the comparator in a first state in the absence of a detection signal being applied. Even when a detection signal is applied, the comparator is not driven into a second state if an operable sensor is connected to the connection point 5. When the sensor is not connected to the connection point, or is inoperable, the voltage produced by the detection signal at the first input of the comparator is high enough to trip the comparator into a second state, which may be latched.

Abstract: An apparatus and method is disclosed for sensing material build-up, such as the undesirable build-up of cotton in a mechanized cotton harvester. A tube is mounted for eccentric rotation adjacent an area where build-up occurs, such as near a doffer. The tube is biased by a spring into one position and is eccentrically rotated against the spring by forces applied to the tube by accumulating material, such as cotton. A switch is mounted within the tube, and, as the tube rotates, the state of the switch changes in accordance with the rotation. A signal generated by the switch is used to alert an operator.

Abstract: A global positioning planter system for planting of seeds by a seed planter. A population control controls the seed planter. A global positioning system computer with digitized maps connects to the population control. The population control connects to the seeder for planting of seeds such as corn or beans or to seed drills for controlling the seed drill, and plants the seeds according to the population control which receives and transmits data with the global positioning system computer.

Abstract: A two-channel metal detector system disposed adjacent the crop feed path of a harvester to detect ferrous metal objects in the crop material is provided with both positive and negative adaptive detection thresholds for each channel, the thresholds being independently varied according to the average positive and negative peaks of the noise component in the channel output signals. A channel output signal is sampled and digitized and the positive and negative peaks of the noise component occurring over fixed time intervals are filtered to provide average positive peak and average noise peak values that are stored in an E.sup.2 PROM and updated according to long term variations in the noise component. The positive and negative adaptive detection thresholds are set according to the average positive and negative peak values and the adaptive detection thresholds are compared with the sample channel output signal to determine if a ferrous metal object has been detected.

Abstract: In a two-channel magnetic metal detector for a forage harvester, positive and negative adaptive detection thresholds are varied according to long term changes in the noise component induced in detection coils by moving ferrous parts of the crop feed mechanism. The adaptive detection thresholds are set at levels determined by the positive and negative peak averages of the noise components in the channels while the crop feed mechanism is running at normal speed. Start-up transient noise induced in the detection coil as the crop feed mechanism accelerates may exceed the adaptive thresholds as thus set, thereby triggering false indications that a tramp metal object has been detected in the crop feed path. At start-up of the crop feed mechanism, the detection thresholds are raised to prevent false indications. An increase in a channel noise signal is taken as an indication that the crop feed mechanism is accelerating.

Abstract: A broken tine detector for agricultural machines is provided for machines such as balers and forage harvesters. The tines form a first plate of a capacitor which rotates about the axis of a reel. The second plate of the capacitor may be provided by a back-plate which is located at the front of an agricultural machine adjacent to the ends of the tines and which is connected to machine ground. An alternate embodiment of the invention is devised by utilizing conductive strips on a tine guard. Each of the conductive strips may be utilized to form the second plate of the capacitor. The row of tines pass through individual slots in the tine guard so that a particular row in which the tine is broken may be detected. When a tine is broken the total capacitance between the tines and the back-plate will change and will be detected, and an indication will be supplied to an operator so that the operator may stop the machine and remove the tines.

Abstract: In a forage harvester which has an automatically adjustable shearbar mechanism for adjusting the distance between the shearbar and a rotating cutterhead, rotation of the cutterhead is determined by the use of essentially steady state signals without substantial transient components.

Abstract: A control system for controlling quantity of hydraulic fluid of an excavator. The control system of this invention provides a method for controlling the quantity of the hydraulic fluid supplied to the swing motor in which in case of swinging operation for driving the swing motor in order to turn the upper frame with respect to the lower frame, the first hydraulic pump is automatically controlled by the controller in order to optimally output hydraulic fluid to timely correspond to starting of the practical swinging operation of the swing motor.

Abstract: The blockage module is designed to be mounted on air seeder seeding equipment. Piezoelectric sensors extending into the flow tubes monitor flow by producing high frequency ringing signals when struck by seeds. During a calibration step, the module will monitor each sensor and adjust the gain of the signal until the number of seed hits per second above a fixed voltage threshold is near a predetermined value. Each sensor connected to the module will be similarly calibrated, and the calibrated gain and hit rate will be stored. It has been found that if a blockage or partial blockage occurs under these calibrated conditions, the number of hits above the fixed voltage threshold will be sharply reduced. The reduced hit rate is compared to the calibrated hit rate, and an alarm is generated if the reduction is great enough. Because the reduced hit rate is immediately detectable, the response time to report a blockage is very short.

Abstract: A grain loss monitor for a harvesting machine is provided with detector mechanism including a sensor plate and a transducer associated with the sensor plate. The detector mechanism is disposed for detecting grain loss through the impact of grain kernals on the sensor plate and the transducer has a resonant frequency in the range of 8 to 25 KHz. The grain loss monitor also includes a circuit operable to process the output signals from the transducer.

Abstract: During monitoring of the driveline of an agricultural implement in respect of overloading and the degree of loading, from a first occurrence of slip, the slip revolutions occurring during a measuring cycle are added up. If the number of slip revolutions exceeds a permissible number of slip revolutions, a signal is generated indicating an overloading condition, a new measuring cycle beginning upon release of the signal to be able to take into account the effects resulting from a change in the behavior of the tractor driver, the nature of the signal being changed responsive to the speed differential between the input speed and output speed of a friction coupling permitting relative rotation.

Abstract: In a forage harvester, a shear bar is adjusted relative to the knives of a rotating cutterhead by selectively energizing first and second motors to move one or the other end of the shear bar toward the cutterhead. A vibration sensor senses vibration of the shear bar and controls a circuit to deenergize an energized motor when vibration is induced in the shear bar. The vibration may be caused by impact of the cutterhead knives on the shear bar (a true hit) or by random noise (detected as a false hit). To discriminate between false hits and true hits, an energized motor is stopped when a first hit (true or false) is detected. A timer is set to time an interval at least as great as the time it takes the cutterhead to make one revolution, and during this interval the vibration sensor is repeatedly sampled to determine if a second hit has occurred. If a second hit is detected during the interval the first hit is assumed to be a true hit.

Abstract: An apparatus is provided for measuring grain loss in a harvesting machine in substantially absolute terms. This apparatus comprises one or more first detectors operable to detect one or more operating condition parameters and to produce a first electrical output signal representative thereof, a plurality of second detectors operable to detect grain separation at a plurality of locations within the machine and to produce second electrical output signals representative thereof, processor means to which the first and second output signals are applied and operable to derive therefrom a substantially absolute indication of grain loss at a given instant, and display means for displaying the grain loss indication.

Abstract: A system for monitoring cotton flow through a conveying system of a cotton harvester. The monitoring system includes acoustic sensors for generating pulses or signals as a function of sound produced from cotton impinging upon a walled conveying duct of the conveying system. The sensors are connected to detector circuitry which provides a first signal condition when cotton flow through the duct is above a first level and a second signal condition when cotton flow is below the first level. The system of the present invention further includes an alarm which is responsive to outputs from the detector circuitry.

Abstract: An apparatus is provided for measuring grain loss in a harvesting machine in substantially absolute terms. This apparatus comprises one or more first detectors operable to detect one or more operating condition parameters and to produce a first electrical output signal representative thereof, a plurality of second detectors operable to detect grain separation at a plurality of locations within the machine and to produce second electrical output signals representative thereof, processor means to which the first and second output signals are applied and operable to derive therefrom a substantially absolute indication of grain loss at a given instant, and display means for displaying the grain loss indication.

Abstract: Apparatus for sensing moisture in crop material includes a probe mounted on a pickup of an agricultural baler for movement between a retracted position and an operative position. The probe has a pair of fingers arranged in a spaced apart relationship so that crop material picked up by the baler bridges the space between the fingers when the probe is in the operative position thus creating a signal path between the fingers. The moisture sensing apparatus also includes a cam roller carried on the pickup to move the probe from its retracted position to its operative position, and a computer connected to the probe to measure the conductance level of the crop material creating the signal path.

Abstract: An agricultural combine is provided with electronic controller cards for assisting in controlling and monitoring the combine. The cards are housed in an enclosure located adjacent to the operator's cab above the ground engaging wheels. The enclosure comprises a box mounted in an aperture formed in the supporting structure and a cover which can be latched to the box. The cover is provided with a number of inwardly extending fingers each having a receiving groove for holding the electronic controller cards. The fingers are arranged in pairs for engaging the cards between the fingers. Openings in the cover are located adjacent to each finger pair for providing an opening through which the electronic controller car held therein can communicate with the wiring harness of the combine. Each opinion is provided with an outwardly extending and encircling flange which engaged a rubber boot of the wiring harness.

Abstract: A tractor coupled to a draft implement through at least one link arm of a hydraulic lift assembly having a lift rod coupled between each link arm and a hydraulic cylinder for raising and lowering the draft implement. A force sensor is coupled to a link arm for providing a measurement of the total force exerted on the link arm. Electrical circuitry provides a measurement of the actual draft force by correcting the total force measurement for lift forces transmitted to the link arm through the corresponding lift rod. A feedback or draft control system is also provided for adjusting the depth of the draft implement in inverse relation to the corrected measurement of actual draft force.

Abstract: Under the control of a microprocessor first and second motors alternately drive first and second ends of a shear bar for adjusting the position of the shear bar relative to cutter head. The shear bar is adjusted so that it is substantially parallel to the cutter head even though the cutter head and shear bar may not be parallel at the time the adjustment is initiated. A knock sensor is provided for sensing impacts between the cutter head and shear bar, the knock sensor output signal being converted to a digital value for controlling the adjusting sequence. A knocker is provided for inducing vibrations in the shear bar to thereby test the operability of the knock sensor and its output circuitry. The sensitivity of the adjustment system to the output of the knock sensor is set automatically before an adjustment sequence begins to account for variations in the knock sensor, its output circuitry, and "noise" vibrations induced in the shear bar by normal machine operation.

Abstract: In a forage harvester having a metal detector with permanent magnets located within a crop feed roll, additional permanent magnets are positioned beyond the ends of the feed roll and at a distance greater than the radius of the feed roll from the axis of rotation of the feed roll. The additional magnets cooperate with magnets within the feed roll to provide a more uniform flux density across the width of the feed roll, even in regions near ferrous side sheets defining the lateral limits of the harvester feed path. Tramp metal is thus detected with equal facility regardless of its trajectory past the feed roll.

Abstract: A sensor apparatus for detecting a flow of material along a given path of travel by detecting a change in the dielectric properties of a portion of the path of travel as the material passes therethrough comprises one or more conductive, plate-like electrodes disposed adjacent the path of travel and generally defining a capacitor having the adjacent portion of the path of travel as a dielectric portion, such that the passage of material to be detected changes the dielectric constant, thereby changing the capacitance. A sensor circuit comprises a tuned circuit having the sensor electrode or electrodes being coupled in circuit therewith. The sensing circuit further comprises an oscillator circuit driving the tuned circuit at a predetermined frequency selected near the resonant frequency of the tuned circuit in the absence of material to be detected.

Abstract: An apparatus for detecting magnetically sensible objects in an object stream longitudinally passing a predetermined location, for instance at the intake end of the conveyor of a field chopper, has according to the invention a support at the location extending transversely adjacent the object stream and having a pair of transverse ends and a center therebetween and a magnet assembly on the support having a north pole directed from between one of the ends and the center of the support transversely of the support and of the stream into the crop stream and a south pole directed parallel to the north pole from between the other end and the center of the support. The assembly forms between its poles a magnetic field having lines of force extending mainly transversely through the stream. Respective north and south sensing coils at least partially surround the respective poles so that a magnetically sensible object perturbing the field will generate respective currents in the coils.

Abstract: A vehicle guidance system which monitors the path of a towed farm implement with respect to a track provided by a previously cut furrow and provides visual cues to the towing tractor operator to maintain the path of the towed implement parallel to the track of the previously cut furrow at a constant, predetermined distance regardless of the path of the tractor towing the implement. The guidance system includes an elongated metal sled runner which is mounted on a doubly articulated carriage device. The sled runner rides in a previously cut furrow and closes an appropriate microswitch if the towed implement veers from the desired path.

Abstract: Silage distributor apparatus has an upper annular stationary member disposed about a flowing silage stream, a silage distributing chute, and a lower annular member rotatably mounted to the upper annular member for disposing the chute in the path of the flowing silage stream. A drive track in the form of a row of apertures is defined on the lower annular member and a drive sprocket is rotatably mounted on the upper annular member and disposed in driving relation with the drive track. A drive motor is removably mounted on the upper annular member and has a rotary output shaft which when the motor is mounted on the upper member is drivingly interengaged with the drive sprocket and when the motor is dismounted therefrom becomes disengaged from the drive sprocket. A sensor is connected to the motor for removal with it and has a contact finger disposed across the path of a row of pins projecting from the lower annular member.

Abstract: This invention monitors the presence of or a flow of discrete small particles having a high dielectric constant, particularly seeds being planted by a seed planting machine. The invention uses the high dielectric constant of the particles, such as seeds, passing at least a pair of spaced electrodes to vary the capacitance between them and thereby indicate presence of the seed. The capacitance variation is detected and then processed by console located display, alarm and/or counting circuitry.

Abstract: A monitoring means for apparatus having a number of functional stations, said means comprising a plurality of sensors or groups of sensors located to monitor the operation of at least some of said functional stations, each sensor having a critical condition indicator adjacent the respective station, a central monitor having a power supply connected via a common connection to each of the sensors and a common signal line connected to the output of each of said sensors wherein each sensor provides an output on activation of the critical condition indicator, said central monitor having an alarm means activated through said signal line wherein each sensor and/or group of sensors provides an output signal to said signal line characteristic of said sensor or group of sensors to cause the alarm means to be activated in a manner characteristic of said sensor or group of sensors.

Abstract: An element placed within a cotton conveying duct of a cotton harvester above the air discharge jet is shaped to shed cotton and supports a vacuum opening which communicates with a simple differential pressure switch through a vacuum conduit. The aspiration effect of normal air flow over the opening provides a vacuum in the conduit which maintains the switch open, but if air velocity in the duct drops below a preselected value due to a plug, low fan speed or faulty hose, the vacuum decreases and the switch closes to energize a warning device.

Abstract: A machine, such as a seed drill, has a conveying member for seeds or the like defining a path along which seed or other material is conveyed in discrete units during normal operations. The machine has an indication arrangement including a distance measuring instrument comprising a proximity sensor adjacent the conveying member for monitoring the pressure of material as it is moved along the path defined by the conveying member. A display panel connected to the distance measuring instrument renders occurrences comprising the movement or lack of movement of the material as sensed by the distance measuring instrument sensorially perceptible.

Abstract: Apparatus for the prediction of performance parameters of a proposed machine, in particular, an agricultural machine, includes a keyboard for entry of data in accordance with a set of input parameters useful in the calculation of performance parameters, a display for displaying performance parameters, a memory for storage of data inputted by the keyboard, and a data processor interconnecting the memory and the numerical board for performing mathematical calculations to output values of the performance parameters in response to the inputting of data at the keyboard. Included within the data processor is an analyzer for selecting input parameters specific to a mathematical correlation, a microprocessor for calculating values of intermediary parameters from the inputted data based on patterns of such data, and a synthesizer employing values of selected input parameters and the intermediary parameters to provide mathematical correlation for attaining values of the performance parameters.

Abstract: A monitoring module is provided for monitoring a plurality of functions and conditions of a vehicle including a plurality of sensors for producing sensor signals in response to a plurality of vehicle functions and conditions. The monitoring module comprises a plurality of inputs each for receiving one of the sensor signals, the inputs being fewer in number than the vehicle functions and conditions to be monitored. The monitoring module also includes a processor responsive to the sensor signals from the inputs for producing display signals corresponding to the values of the respective functions and conditions. The monitoring module further includes a memory for storing data and instructions for enabling the processor to respond to any of the sensors for monitoring any of the vehicle functions and conditions. The monitoring module further includes a sensor identifying arrangement for producing signals to identify the particular sensors coupled to the inputs.

Abstract: A device is provided for supplying material with unit doses of particulate parasiticidal composition, comprising, in combination:(1) a supply of particulate parasiticidal composition;(2) a feeder for feeding unit doses in regular sequence from the supply to the material;(3) a capacitive approach switch for sensing each unit dose as fed to the material;(4) a timer for timing the interval between unit doses; and(5) a signalling device for giving a signal when the interval between doses exceeds a predetermined limit.

Abstract: A monitoring circuit is provided for a metal detector which includes a metal sensor for producing a sensor signal in response to the passage of a metallic object through a rotating apparatus and a tachometer for producing a tachometer signal at a frequency proportional to the rate of rotation of the rotating apparatus. In accordance with the invention, the monitoring circuit comprises an adjustable tracking filter responsive to a predetermined control signal for tracking the frequency of the sensor signal in a predetermined fashion and a control circuit responsive to the tachometer signal for producing the control signal.

Abstract: A monitor is provided for a field planting machine having a plurality of planting units and a plurality of seed sensors respectively associated with the planting units for producing seed signals in response to the dispensing of seeds thereby. The monitor comprises a plurality of sensor circuits coupled in series circuit, one of the sensor circuits being coupled intermediate each of the sensors and a common signal line. These sensor circuits and the associated sensors are sequentially selectable for causing a first condition on the common signal line in response to production of seed signals at or above a predetermined rate and a second condition on the common signal line in response to the non-production of seed signals at or above the predetermined rate.

Abstract: A harness adapter is disposed between the seed monitor logic circuitry and the individual row unit seed detectors upon conversion of a planter for operation of only a portion of its planting units. The adapter provides a continuous series of connections from the detectors associated with operative row units while electrically isolating the detectors on the non-operative row units.

Abstract: A seed flow monitor for use with a plurality of seed flow sensors which are located in individual tubes of a field seeder. In the event of detection of reduction of seed flow in any seed tube below a predetermined threshold, a pulse signal is sent to a central display via circuits, associated with each group of seed flow sensors, connected in series. Each of the circuits modifies the pulse signal in a predetermined similar manner, resulting in a pulse signal received at the central display which is unique to the group of seed tubes originating the pulse signal. Preferably the pulse signal is constantly transmitted to the circuits by the central display, and is merely coupled into the series of circuits upon detection of the seed flow below the threshold. The cabling complexity from the sensors to the control display is thus substantially reduced and reliability is enhanced.

Abstract: Apparatus for providing information for an agricultural work machine comprising a distance detector which detects the distance travelled by an agricultural vehicle, a fuel consumption detector, which detects the amount of fuel consumed by the engine of the agricultural vehicle, a circuit for inputting the working width of the agricultural vehicle, an operating circuit for calculating fuel consumption rate indicative of the amount of fuel consumed per unit working area, and a display for displaying the calculated information. The fuel consumption detector may be replaced with a timer which detects the working time of the agricultural vehicle so that working efficiency may be obtained in place of the fuel consumption rate. The total area to be worked may be input in order to estimate the time of completion of the agricultural work or the fuel consumption rate at the time of completion of the work.

Abstract: An Agricultural combine having a sickle reciprocated by a wobble drive mechanism and a torsion bar coupled to the sickle to reduce the input torque requirement of the drive mechanism, is provided with a warning system to operate an alarm when energy is still stored in the torsion bar, unknown to the operator, when the drive mechanism is shut down and which stored energy could reciprocate the sickle and represent a hazard to the operator. The hazard warning system is disabled when the drive mechanism is operating.

Abstract: Disclosed is metal detector apparatus for protecting the crop processing unit of a forage harvester. A magnetic field is provided in the area through which crop material is being fed. The field is produced by magnets mounted in a pattern that creates lines of flux at an angle to the general direction of movement of material. A unique pick-up coil arrangement with windings in the magnetic field provides induced signals responsive to the presence of metal objects in the field.

Abstract: A machine has two relatively movable portions and relative movement between the portions is sensed by means generating an electric current. In the preferred embodiment this means comprises a permanent magnet on one portion and an induction coil and a soft-iron core on the other portion. The two portions are parts of an overload coupling interconnected with a shear pin. When the coupling is overloaded, a shear pin fractures and the two portions rotate relative to one another. This causes a current to be generated in the coil which actuates a signal element. The device provides a visual indication of the operative condition of the two portions.

Abstract: A forage harvester includes four multiple-bladed rotary cutting segments positioned near a shearbar. Four proximity sensors are mounted in shearbar bores near each of the cutting segments, each including a permanent magnet and a sensing coil. Blade motion near the sensors produces an electrical signal in the sensing coils. The signals from each sensing coil are integrated, sampled and averaged. The largest average signal is conditioned and applied to an analog meter for display to a vehicle operator. Switch and logic circuits permit the operator to monitor only selected one or ones of the cutting segments.

Abstract: A modular monitoring and control system is provided for an agricultural machine such as a combine. The system includes an executive processing unit which is capable of cooperating with one or more monitoring and/or control modules, which module may be added to or deleted from the system for performing monitoring and control functions as desired by a particular operator. Conveniently, a video display unit provides alphanumeric display information to the operator regarding both the monitored and controlled functions of the combine machine as well as instructional messages for purposes of calibrating the monitoring and control system for operation with a particular combine. Moreover, the operator may select for a display in alphanumeric form suitable instructional information regarding any malfunctions of the combine and counter during operation and instructions for the correction thereof.

Abstract: A seed planter monitor is used with a traveling seed planter operable to periodically dispense seeds in each of a plurality of rows. The monitor scans the outputs of seed sensors which provide electrical signals as the seeds are dispensed. A detector triggers an alarm in the absence of output signals from an examined seed sensor during a predetermined time period. A visual display identifies the row being examined by the scanner.

Abstract: Metal detectors having parallel magnetic fields produce signals which vary depending upon the shape and orientation of a metal object passing through the field. An improved metal detector sensor includes a magnet of special configuration having a multi-directional magnetic field resulting in a detector which is insensitive to orientation of the detected metal. One embodiment of the magnet is a pattern of cylindrical poles with the opposing pole central to the cylinder, thus creating a multiplicity of radially extending magnet fields. An alternate embodiment of the invention is an offset pattern of opposite poles which create two groups of fields, each at an angle to the general direction of movement of the material fed into the machine.

Abstract: A digging and planting machine is provided having a tubular digging and planting tool mounted on a vehicle travelling along the ground surface, and at least one sensing and signalling means for sensing the resistance of the ground to penetration by the digging tip of the tool, thus gauging the condition of the ground, and detecting obstacles to such penetration, so as to ensure that the digging tip provides and a plant is fed to a planting hole of the desired depth, when ground condition is suitable, and, when ground condition is not suitable, that new digging attempts continue to be made at closely-spaced intervals as the vehicle travels over the ground until a planting hole of the desired depth is dug, so as to plant as many plants as close together as desired per unit area.

Abstract: Under the control of a microprocessor first and second motors alternately drive first and second ends of a shear bar for adjusting the position of the shear bar relative to cutter head. The shear bar is adjusted so that it is substantially parallel to the cutter head even though the cutter head and shear bar may not be parallel at the time the adjustment is initiated. A knock sensor is provided for sensing impacts between the cutter head and shear bar, the knock sensor output signal being converted to a digital value for controlling the adjusting sequence. A knocker is provided for inducing vibrations in the shear bar to thereby test the operability of the knock sensor and its output circuitry. The sensitivity of the adjustment system to the output of the knock sensor is set automatically before an adjustment sequence begins to account for variations in the knock sensor, its output circuitry, and "noise" vibrations induced in the shear bar by normal machine operation.