MOBILE SELF-SUPPORTING TILLER

• US 3,633,679 A
• Filed: 10/13/1969
• Issued: 01/11/1972
• Est. Priority Date: 10/13/1969
• Status: Expired due to Term

• Current Assignee: LDI, Inc.
• Original Assignee: Franklyn L. Dahlberg, Willie F. Brewer
• Inventors: Dahlberg, Franklyn L., Brewer, Willie F.
• Primary Examiner(s): Pulfrey, Robert E.
• Assistant Examiner(s): Rader, R. T.
• Application Number:
  US04/865,807
• Time in Patent Office: 820 Days
• Field of Search: 172/118,452,465,492,407,413,310,315,316,483,484,47,76,79,119-123,307,49,51,100
• US Class Current: 172/123
• CPC Class Codes: A01B 33/021 with rigid tools
• CPC Class Codes: A01B 63/22 operated by hydraulic or pneumatic means

Abstract

A self-supporting tiller having a jackknife frame mounted on two front caster wheels and two rear caster wheels. A hydraulically operated lifting mechanism which is included in a tiller control system is carried by the self-supporting tiller and is responsive to speed changes of a power input shaft connected to a rotary ground-working tool and to a hydraulic pump for raising the tiller when forces on the tool cause the speed of the input shaft to drop below a predetermined minimum speed and to effect lowering of the tool when the shaft speed returns to the predetermined minimum speed. The control system includes a manually operated control which bypasses the automatic controls and is used for manual raising of the tool. The control system also includes front caster wheel locks which automatically prevent the front caster wheels from pivoting/out of position which will guide the tiller along a straight forward path when the tool is lowered into tiller position, and which releases the caster wheel for free-swinging movement when the tool is raised. Manually operated rear caster locks are provided for locking the rear wheels in a straight forward position when the rotary tool is raised and is to be transported long distances.

Claims

1. A mobile self-supporting tiller comprising a rotary groundworking tool, a pivotal frame rotatably supporting said tool, a plurality of wheels including front and rear wheels providing sole support for said frame, linkage means movable connecting said frame to said wheels, a power cylinder supported by said frame and connected to said linkage means for lifting said tool, a pump on said frame, an adjustable lift control hydraulic system connecting said pump to said cylinder, power means connected to said frame for moving said frame along a predetermined path, power-transmitting means including an input shaft extending between said front wheels and said rear wheels connecting said power means to said pump and to said ground-working tool, an adjustable underspeed governor on said frame driven by said input shaft, and control means for said hydraulic system operated by said adjustable underspeed governor for causing said power cylinder to lift the tool when the speed of said input shaft falls below a predetermined value.

2. The tiller of claim 1, wherein said power means is supported on a towing vehicle which towing vehicle comprises an engine, a variable speed transmission connected to drive wheels, and a power takeoff shaft driven at speeds independent of the speed of the drive wheels, said input shaft being driven by the power takeoff shaft.

3. A mobile self-supporting tiller according to claim 2 wherein two of said frame supporting wheels are front caster wheels which are disposed outwardly of the drive wheels of said vehicle, and additionally comprising lock means for locking said front caster wheels in a straightforward position, and means responsive to the downward movement of the tool into the soil for locking said front wheels in a straight forward position and responsive to movement of the tool Out of the soil to release the caster wheels for free castering movement.

4. A mobile self-supporting tiller adapted to be connected to and moved along a path by a steerable towing vehicle including drive wheels, a power takeoff, an engine, and means for drivingly coupling said engine to the drive wheels and to the power takeoff:

comprising a frame;

a rotary ground-working tool supported by said frame;

a plurality of front wheels;

front movable mounting means for connecting said wheels to said frame;

a rear wheel;

rear movable mounting means for connecting said rear wheel to said frame;

a power cylinder supported by said frame and having a piston rod projecting therefrom;

a linkage system movably mounted on said frame and connected to said piston rod and to said front and rear mounting means;

a fast-operating hydraulic system hydraulically independent of said towing vehicle and including a pump mounted on said frame;

power transmitting means adapted to be coupled to said power takeoff and including a power input shaft drivingly connected to said rotary ground-working tool and to said pump;

said shaft normally being driven within a predetermined speed range during the tilling operation; and

a tiller control system including adjustable lift control means operatively connected between said power cylinder, said pump, and said input shaft;

said lift control means including selectively adjustable speed control means responsive to a reduction of the normal input shaft speed to a speed less than said predetermined speed for activating said lift control means for directing fluid into said power cylinder so that the ground-working tool will be lifted from its lowermost working depth, and wherein input shaft speeds within said predetermined speed range will cause said speed control means to deactivate said lift control means causing the power cylinder to lower said tool.

5. A mobile self-supporting tiller according to claim 4 wherein said front wheels are widely spaced caster wheels and wherein said towing vehicle'"'"''"'"'s power-driven wheels are disposed between said front caster wheels thereby permitting sharp turns.

6. A mobile self-supporting tiller according to claim 4 wherein said lift control means includes adjustable speed control means which controls the rate of upward movement of the ground-working tool thereby adapting the tiller to operate efficiently in different types of soil.

7. A mobile self-supporting tiller according to claim 6 wherein said adjustable speed control means is also adapted to control the rate of downward movement of said ground-working tool.

8. A mobile self-supporting tiller according to claim 6 wherein the upward movement of the ground-working tool from its lowermost position to its uppermost position requires between about 3 to 4 seconds.

9. A mobile self-supporting tiller comprising a frame;

a rotary ground-working tool supported by said frame;

a plurality of front wheels;

front movable mounting means for connecting said wheels to said frame;

a rear wheel;

rear movable mounting means for connecting said rear wheel to said frame;

a power cylinder supported by said frame and having a piston rod projecting therefrom;

a linkage system movably mounted on said frame and connected to said piston rod and to said front and rear mounting means;

a pump on said frame;

power means connected to said frame for moving said frame along a path;

said power means including a power input shaft drivingly connected to said rotary ground-working tool and to said pump;

said shaft normally being driven within a predetermined speed range during the tilling operation;

a tiller control system including lift control means positively connected between said power cylinder, said pump, and said input shaft;

said lift control means including speed control means responsive to a reduction of the normal input shaft speed to a speed less than said predetermined speed for activating said lift control means for directing fluid into said power cylinder so that the ground-working tool will be lifted from its lowermost working depth, and wherein input shaft speeds within said predetermined speed range will cause said speed control means to deactivate said lift control means causing the power cylinder to lower said tool;

said frame supporting wheels being caster wheels, and a plurality of rear caster wheels and rear movable mounting mean being provided;

said front and rear movable mounting means including parallelogram linkages pivotally connected to said frame and to said associated caster wheels;

front caster wheel locking means;

each locking means comprising a plate mounted to caster with said associated caster wheel and having a hole therein movable in an arcuate path, a locating pin disposed in alignment with said arcuate path and position to enter said hole when said caster wheel is disposed in a straightforward position, a cam secured to the associated parallelogram linkage, and resilient means disposed between said cam and said locking pin, downward movement of said tool being effective to compress said resilient means and to move said locking pin into said hole when the hole swings into alignment with said pin, upward movement of said tool being effective to move said cam away from said resilient means allowing said resilient means to remove said locking pin from said hole.