초록 ▼

An agricultural machine having a machine element supported by and movable relatively to a wheel-supported main frame with power means for moving it up and down relatively in small incremental steps, to vary the distance to ground level. The distance to ground is determined and electrical signals cor

An agricultural machine having a machine element supported by and movable relatively to a wheel-supported main frame with power means for moving it up and down relatively in small incremental steps, to vary the distance to ground level. The distance to ground is determined and electrical signals corresponding to the distance generated. A control circuit receives the signals and provides “up”and “down”pulses. A monitor-controller circuit receives the “up”and “down”pulses and transmits them to the power means for actuating an incremental step up or down for each pulse. The monitor-controller determines whether a preselected member of consecutive “down”pulses occur without an “up”pulse between them and within a short predetermined time period and actuates circuit disabling and override means only when the preselected number of “down”pulses occur within the predetermined time period; if so, further “down”pulses are prevented from passing to the power means, and both “up”and “down”pulses are nullified for a set time period, during which the machine element is moved toward or to its initial position.

대표청구항 ▼

An agricultural machine including in combination: a wheel-supported main frame, a machine element movable relatively to said main frame, and having an initial position, power means on said frame for moving said element up and down relatively to said main frame in small incremental steps, to vary the

An agricultural machine including in combination: a wheel-supported main frame, a machine element movable relatively to said main frame, and having an initial position, power means on said frame for moving said element up and down relatively to said main frame in small incremental steps, to vary the distance between a portion of said element and ground level, distance-determining means mounted on said element for determining the distance between itself and ground level and for generating electrical signals corresponding to such distance, a control circuit supported by said frame, receiving said signals and providing “up”pulses and “down”pulses according to whether said distance is decreasing or increasing, said control circuit including a monitor-corrector having a counter preset for a predetermined number of enabling “down”pulses and having a pulse input for said “down”pulses, a pulse output, a reset, and output enabling means for enabling said pulse output only when said predetermined number of enabling “down”pulses is applied to said pulse input before the reset is actuated, time delay means for actuating said counter reset after a short predetermined time interval, a “down”actuator AND gate connected to said control circuit and normally enabled to pass a “down”pulse, a “down”actuator switch actuated by said “down”actuator AND gate, “down”applying means for applying each “down”pulse to said “down”actuator AND gate, to said pulse input, and to said time delay means to initiate said predetermined time interval, an “up”actuator AND gate connected to said control circuit, normally enabled to pass an “up”pulse, an “up”actuator switch connected to the output from said “up”actuator AND gate, “up”applying means for applying each “up”pulse to said counter reset to enable said counter, first and second one-shot multivibrators connected in series to the output from said counter and including a time delay in said second one-shot multivibrator, each said multivibrator having output means, override means connected to the output means of said first one-shot multivibrator and to said “up”actuator switch for sending an “up”pulse to said power means upon actuation of said first multivibrator, and disabling means connected to said output means of said second one-shot multivibrator and to both said AND gates to disable further actuation of both said “up”actuator AND gate and said “down”actuator AND gate for a predetermined time interval.