Agricultural implement and depth control therefor

• US 4,355,688 A
• Filed: 01/29/1981
• Issued: 10/26/1982
• Est. Priority Date: 01/29/1981
• Status: Expired due to Fees

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Hamm, Nicholas, Rosbak, John
• Primary Examiner(s): Stouffer, Richard T.
• Application Number:
  US06/229,399
• Time in Patent Office: 635 Days
• Field of Search: 172/4, 172/26, 172/424, 172/430, 56/10.2, 56/DIG. 10, 56/DIG. 15, 37/DIG. 1, 180/131, 104/244.1
• US Class Current: 172/4
• CPC Class Codes: A01B 63/32 operated by hydraulic or pneumatic means without automatic control

Abstract

A depth control system for a disk tiller or similar groundworking implement having a gang of tillage tools adjustably supported from a main frame. A trailing support arm is rigidly connected to the gang and pivotally carries a gauge wheel spring-biased into engagement with the tilled soil. As the depth of the tools varies with changing conditions, the support arm moves and the gauge wheel pivots with respect to the arm to rotate a first lever. The first lever is operably connected to a second lever by a pair of pretensioned springs. Movement of the second lever moves a switch activating arm which activates one of a pair of microswitches. The microswitches control solenoid valves to operate a depth control cylinder for the gang and maintain the desired depth of cut. The switch activating arm is dampened by a dashpot which, together with the springs, prevents switch activation during short periods of oscillation.

Claims

1. In an earthworking implement, a main frame supported for forward movement over the ground, an earthworking tool assembly having a tool frame and soil penetrating tools connected to the tool frame, means for rockably connecting the tool frame to the main frame, power means for rocking the tool frame to raise and lower the tools with respect to the main frame to vary the depth of penetration of the tools, a fore-and-aft extending support arm fixed at one end to the tool frame forwardly of the soil penetrating tools for rocking therewith and extending rearwardly from said one end up and over the soil penetrating tools to an opposite end thereof spaced rearwardly from the tool assembly, said opposite end movable vertically as the tool frame is raised and lowered, depth gauging means extending downwardly from said opposite end of the support arm so as to be movable into contact with the soil for sensing the position of the arm relative to the ground, said depth gauging means comprising a wheel connected to said opposite end of the arm for castering about an upright axis and for rocking vertically about a generally horizontal transverse axis adjacent the upright axis as the support arm rocks, and means responsive to the rocking of the caster wheel about said transverse axis for providing a signal indicative of whether the depth of penetration of the tools is above or below a preselected range, and wherein said power means is responsive to the signal for rocking and tool frame to maintain the depth of penetration of the tools within the preselected range.

2. The invention as set forth in claim 1 wherein the tool frame is connected to the main frame for rocking about a generally transverse axis and the arm is connnected to the tool frame adjacent said transverse axis and extends rearwardly therefrom so that the wheel is positioned to be urged into rolling contact with the tilled soil.

3. In an earthworking implement, a main frame supported for movement over the ground, an earthworking tool assembly having soil penetrating tools, said assembly pivotally connected to the frame for swinging about a first generally horizontal axis, a fore-and-aft extending arm having one end connected to the earthworking tool assembly for swinging therewith and having the other end rockable between a raised and a lowered position as the tool assembly swings about the axis, a wheel assembly movably connected near the other end of the arm, said wheel assembly including a ground-engaging wheel, and means for moving the wheel assembly for urging the wheel into ground contact as the other end of the arm rocks between its positions, controllable power means connected to the earthworking tool assembly for swingably positioning the latter and adjusting the tool penetration, and control means for sensing the movement of the wheel assembly and responsive to said movement to control the power means, wherein said control means comprises a first lever swingable with pivoting of the wheel assembly about a first pivotal axis and a second lever spaced from and swingable in substantial unison with the swinging movement of the first lever about a second pivotal axis substantially parallel to the first axis, and spring means between the first and second levers for urging the second lever to move in substantial unison with the first lever.

4. The invention as set forth in claim 3 wherein the other end of the arm extends rearwardly of the tools so that the ground wheel is positioned to be urged into engagement with the tilled soil.

5. The invention as set forth in claim 3 further comprising means for dampening the pivoting of the second lever.

6. In an earthworking implement comprising:

a mobile frame;

a lift arm carried by the frame and rockable about a generally horizontal axis between raised and lowered positions;

tool means movable with the lift arm for penetrating the ground at a depth dependent on lift arm position;

a support arm connected for movement with the lift arm;

a gauge wheel assembly pivotally connected to and movable with the support arm, said assembly including a ground-engaging wheel and means for urging said wheel into contact with the ground;

a lever connected to and rockable with the gauge wheel assembly;

an actuating arm connected to and rockable with the lever between first and second positions;

switch means effective to provide first and second signals as the actuating arm rocks to its respective first and second positions;

spring means connected between the lever and the actuating arm for urging the actuating arm to move with the lever and dampener means connected to the actuating arm for preventing the switch means from being responsive to intermittent oscillations of the gauge wheel assembly; and

power means responsive to the first and second signals for adjustably rocking the lift arm between its raised and lowered positions.

7. The invention as set forth in claim 6 further comprising means for selectively varying the relative positions of the lever and the gauge wheel assembly to adjust the preselected depth.

8. The invention as set forth in claim 7 wherein the means for selectively varying the relative position comprises adjustable securing means for selectively connecting the lever in one of a plurality of positions with respect to the gauge wheel assembly.

9. The invention as set forth in claim 6 further comprising means for adjusting the amount of rocking of the actuating arm relative to the lever.

10. In an earthworking implement, a main frame supported for forward movement over the ground, an earthworking tool assembly having soil penetrating tools, said assembly pivotally connected to the frame for swinging about a first generally horizontal axis, a fore-and-aft extending arm having one end connected to the earthworking tool assembly for swinging therewith and having the other end rockable between a raised and a lowered position as the tool assembly swings about the axis, a wheel assembly movable connected near the other end of the arm, said wheel assembly including a ground-engaging wheel, and means for moving the wheel assembly for urging the wheel into ground contact as the other end of the arm rocks between its positions, controllable power means connected to the earthworking tool assembly for swingably positioning the latter and adjusting the tool penetration, and control means for sensing the movement of the wheel assembly and responsive to said movement to control the power means, wherein said control means comprises a first lever swingable with pivoting of the wheel assembly and a second lever spaced from and swingable in substantial unison with the swinging movement of the first lever, spring means between the first and second levers for urging the latter to move in substantial unison with the first lever, and means for dampening the pivoting of the second lever.

11. The invention as set forth in claim 10 wherein the other end of the arm extends rearwardly of the tools so that the ground wheel is positioned to be urged into engagement with the tilled soil.

12. The invention as set forth in claim 10 wherein the first and second levers are swingable about substantially parallel pivotal axes.