Guidance system for towed vehicles
First Claim
1. In combination, a towed farm implement having first and second opposite sides with a tool bar extending therebetween and a tongue structure extending forwardly from said tool bar, anda guidance system for said implement comprising,a compensating hitch means pivotally secured at its rearward end to the forward end of said tongue structure and adapted to be connected at its forward end to the lower links of a three-point hitch of a prime mover,control means for selectively adjusting the position of said hitch means with respect to the lower links of a three-point hitch of a prime mover to which it is attached,means for marking a furrow in the ground as said implement is towed, said marking means extending from said sides of said implement,a follower extending from said implement to be operationally engaged by said furrow so that said implement is a predetermined distance from said furrow,detecting means operatively connecting to said follower for electrically detecting the deviation of said implement from said predetermined distance from said furrow, andan electronic circuit means electrically connecting said control means to said detecting means so that a predetermined deviation of said implement from said predetermined distance from said furrow activates said control means to adjust the position of said hitch means to align said implement at said predetermined distance from said furrow.
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Accused Products
Abstract
An automatic guidance system for towed vehicles is disclosed comprising a marker, a position sensor, an electronic operational amplifier circuit, an electrical servo controlled hydraulic valve, and a hydraulically controlled swinging draw bar hitch. The position sensor comprises a follower to follow the furrow mark in the ground made by the marker on the preceding pass of the farm implement over the ground and variable resistors mounted on the followers electrically connected to the amplifier circuit. The electrical servo controlled hydraulic valve is driven by the operational amplifier circuit in response to the varying output voltages received from the variable resistors responding to the position of the follower. The position of the towed implement relative to the furrow mark is adjusted by the action of the hydraulically controlled swinging draw bar responding to the operation of the electrical servo controlled hydraulic valve. Deviation of the towed implement from its desired position relative to the furrow mark is detected by the position sensor and corrected by the movement of the hydraulically controlled swinging draw bar responding to the variable resistor outputs of the position sensor via the operational amplifier circuit and electrical servo controlled hydraulic valve. An adjustment apparatus is provided to enable the operator to change the angular displacement of the follower necessary to actuate the electrical servo controlled hydraulic valve, thereby allowing various degrees of implement positioning error. A control switch is provided to allow manual regulation of the servo controlled hydraulic valve and thereby manually control the swinging draw bar to position the implement.
70 Citations
18 Claims
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1. In combination, a towed farm implement having first and second opposite sides with a tool bar extending therebetween and a tongue structure extending forwardly from said tool bar, and
a guidance system for said implement comprising, a compensating hitch means pivotally secured at its rearward end to the forward end of said tongue structure and adapted to be connected at its forward end to the lower links of a three-point hitch of a prime mover, control means for selectively adjusting the position of said hitch means with respect to the lower links of a three-point hitch of a prime mover to which it is attached, means for marking a furrow in the ground as said implement is towed, said marking means extending from said sides of said implement, a follower extending from said implement to be operationally engaged by said furrow so that said implement is a predetermined distance from said furrow, detecting means operatively connecting to said follower for electrically detecting the deviation of said implement from said predetermined distance from said furrow, and an electronic circuit means electrically connecting said control means to said detecting means so that a predetermined deviation of said implement from said predetermined distance from said furrow activates said control means to adjust the position of said hitch means to align said implement at said predetermined distance from said furrow.
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12. In combination with an implement having a tongue means rigidly connected thereto and extended forwardly therefrom, a compensating hitch means comprising,
an elongated swinging drawbar member having frontward and rearward ends and comprising a single rigid element extending from said frontward end to said rearward end, said frontward end adapted for pivotal connection to a prime mover and said rearward end adapted for pivotal connection to said implement, a hydraulic cylinder pivotally connected at one end to said drawbar member and adapted at the other end for pivotal connection to a prime mover, said drawbar member including hydraulic cylinder connecting means rigidly affixed to said rigid element, said one end of said hydraulic cylinder being directly connected to said connecting means such that the extension of the cylinder arm causes said drawbar to pivot in one transverse direction relative to said prime mover and the retraction of said arm causes said drawbar to pivot in the other transverse direction relative to said prime mover, and means for controlling the extension and retraction of said cylinder arm, said tongue means being directly pivotally connected to said rigid element at said rearward end of said elongated swinging drawbar member whereby said tongue means is transversely moved in unison with said rearward end of said elongated swinging drawbar member for direct corrective steering of said implement in response to pivotal movement of said drawbar member.
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14. A field implement comprising,
a tool bar, a tongue structure extending forwardly from said tool bar, a compensating hitch means pivotally secured to the forward end of said tongue at its rearward end and adapted to be connected by its forward end to the lower links of a three-point hitch of a prime mover, control means on said compensating hitch for selectively adjusting the position of said hitch with respect to the lower links of the three-point hitch of a prime mover to which it is attached, means on said tool bar for creating a furrow in the direction of travel of said tool bar, guide means on said tool bar adapted to follow in said furrow, and means operatively connecting said guide means and said control means whereby the operation of said control means is influenced by said guide means.
Specification