Tobacco harvester having a hydraulic control system for automatically and continuously controlling the speed of a leaf defoliator assembly in relation to the harvester ground speed

• US 3,999,359 A
• Filed: 05/20/1975
• Issued: 12/28/1976
• Est. Priority Date: 05/20/1975
• Status: Expired due to Term

• Current Assignee: Harrington Manufacturing Company
• Original Assignee: Harrington Manufacturing Company
• Inventors: Jordan, Bertram Lee, Mitchell, John Davis
• Primary Examiner(s): Kinsey, Russell R.
• Application Number:
  US05/579,195
• Time in Patent Office: 588 Days
• Field of Search: 56/27.5, 56/10.2, 56/10.3, 56/10.4
• US Class Current: 56/27.5
• CPC Class Codes: A01D 45/16 of tobacco
• CPC Class Codes: Y10S 56/01 Crusher

Abstract

A tobacco harvester having a hydraulic control system for automatically and continuously controlling and maintaining the speed of a leaf defoliator assembly relative to and in proportion to the ground speed of the tobacco harvester. The hydraulic control system is adapted to continuously control the horizontal rearward speed component of the defoliating elements of a leaf defoliator assembly such that the defoliating elements move rearwardly during leaf defoliation at approximately the same speed the harvester is moving forward.

To provide for continuous speed control of the defoliator assembly, the hydraulic speed control system is operative to continuously effectively sense or monitor harvester ground speed and to continuously drive the defoliator assembly in proportion to the effectively sensed or monitored ground speed. In addition, the output of said hydraulic control system for controlling the speed of the defoliator assembly can be varied independently of harvester ground speed in order to synchronize or adjust the horizontal rearward speed component of the defoliating elements associated with said defoliator assembly to equal or nearly equal the forward ground speed of the harvester. Thus, the speed of the defoliator assembly is not only controlled and driven in proportion to the harvester ground speed, but the horizontal rearward speed component of the defoliating elements are driven at a speed approximately equal to the harvester ground speed. Consequently, once a certain speed relationship is established between the defoliator assembly and the harvester ground speed, this same speed relationship continues to exist for any and all harvester speeds. The result is that the defoliating elements during leaf defoliation move inwardly into the plane of the stalk row and outwardly therefrom in a continuous synchronized relationship with the passing tobacco stalks without significantly bending, breaking or cutting the stalks passing through the defoliator assembly.

Claims

1. In an automatic tobacco harvester of the type having a wheel supported mobile frame adapted to move through a tobacco field, a leaf defoliator assembly mounted on said frame and having defoliating elements that are adapted to defoliate tobacco leaves from successive tobacco stalks aligned in a row as the harvester moves through the tobacco field, defoliator drive means operatively connected to the defoliator assembly for driving said defoliator assembly, and a leaf conveyor assembly means mounted on said mobile frame and operative to receive the defoliated tobacco leaves and to convey them to a collection area operatively associated with said tobacco harvester;

the improvement comprising;

an automatic hydraulic speed control system for continuously and automatically controlling and maintaining the speed of the defoliator assembly relative to and in proportion to the ground speed of said tobacco harvester as said harvester moves through the field during a harvesting operation, said automatic hydraulic speed control system including hydraulic motor means operatively connected to said defoliator drive means for driving the same;

a hydraulic fluid flow control unit operatively connected to a source of hydraulic fluid and operatively associated with said hydraulic motor means for driving the same; and

said hydraulic fluid flow control unit of said hydraulic speed control system having control means operatively associated therewith and continuously responsive to harvester ground speed and changes therein for automatically directing according to harvester ground speed a system of fluid with a volumetric flow rate generally proportional to the harvester ground speed from said hydraulic fluid flow control unit to said hydraulic motor means for continuously driving said defoliator assembly at a speed generally proportional to the ground speed of said tobacco harvester such that the speed of the said defoliator assembly is continuously controlled and maintained at a speed proportional to the ground speed of said tobacco harvester irrespective of changes in the harvester ground speed as it moves through the tobacco field.

2. The automatic tobacco harvester and improved hydraulic defoliator speed control system of claim 1 wherein said control means includes:

a variable displacement hydraulic pump operatively connected to said hydraulic motor that drives said defoliator drive means, and adapted to drive the same hydraulic motor by driving a system of fluid to and from the hydraulic motor;

said variable displacement hydraulic pump having means associated therewith for varying the volumetric fluid output to said hydraulic motor independently of the driven speed of said variable displacement hydraulic pump; and

a main drive hydraulic motor operatively connected to said variable displacement hydraulic pump for driving the same, said main hydraulic motor being operatively connected within a hydraulic wheel drive system of the harvester such that the same is driven in proportion to the harvester ground speed.

3. The automatic tobacco harvester and the improved hydraulic defoliator speed control system of claim 1 wherein said control unit and the control means thereof includes:

a hydraulic pump means operatively connected between a source of hydraulic fluid and said hydraulic motor that drives said defoliator drive means for driving said hydraulic motor by directing a system of fluid to and from the hydraulic motor; and

drive means responsive to harvester ground speed for driving said hydraulic pump means in proportion to harvester ground speed.

4. The automatic tobacco harvester and improved hydraulic defoliator speed control system of claim 3 wherein said drive means for driving said hydraulic pump means includes a main drive hydraulic motor operatively connected in a hydraulic wheel drive system associated with said harvester, said main drive hydraulic motor being connected in series with at least one wheel being propelled by said harvester'"'"'s hydraulic wheel drive system and operatively connected to said hydraulic pump means for driving the same.

5. In an automatic tobacco harvester of the type having a wheel supported mobile frame adapted to move through a tobacco field, a leaf defoliator assembly having defoliating elements associated therewith mounted on said frame and adapted to be driven so as to engage and defoliate tobacco leaves from successive tobacco stalks aligned in a row as the harvester moves through the tobacco field, and a leaf conveyor assembly means mounted on said mobile frame and operative to receive the defoliated tobacco leaves and to convey them to a collection area operatively associated with said tobacco harvester;

the improvement comprising an automatic hydraulic speed control system for automatically and continuously controlling and maintaining the rearward speed of the defoliating elements of said defoliator assembly approximately equal to the forward ground speed of said tobacco harvester as said harvester moves through the field during a harvesting operation, said automatic hydraulic speed control system comprising;

hydraulic drive means operatively connected to the defoliator assembly for driving said defoliator assembly as said tobacco harvester moves through the field;

a hydraulic speed control unit operatively connected to a source of hydraulic fluid and to said hydraulic defoliator drive means for driving the same; and

said hydraulic speed control unit having means operatively associated therewith for continuously effectively sensing the ground speed of said harvester and variations in the ground speed of said harvester and for causing a system of fluid to be directed from said hydraulic speed control unit to said hydraulic defoliator drive means at certain rates for continuously driving said defoliator assembly at a speed proportional to the effectively sensed ground speed of said tobacco harvester such that the rearward speed of the defoliating elements is continuously controlled and maintained at a speed approximately equal to the forward ground speed of said tobacco harvester irrespective of changes in the harvester forward ground speed as it moves through the tobacco field.

6. A tobacco harvester having an automatic hydraulic speed control system for varying and continuously controlling and maintaining the operating speed of a leaf defoliator assembly relative to and in proportion to the ground speed of said harvester, comprising in combination:

a mobile frame structure;

ground engaging wheel means rotatively mounted on said mobile frame;

a hydraulic wheel drive system operatively disposed on said harvester and operatively connected to said ground engaging wheel means for hydraulically driving the same;

a leaf defoliator assembly mounted on said mobile frame and having a plurality of lead defoliating elements that are adapted during leaf defoliation to extend transversely between successive stalks and wherein adjacent pairs of said defoliating elements closely surround portions of each stalk and move vertically up the stalk to effectuate defoliation and rearwardly therewith as the stalk passes through the defoliator assembly;

defoliator drive means for driving said defoliator assembly and including a defoliator hydraulic drive motor operatively connected to said defoliator assembly for driving the same;

a leaf conveyor assembly disposed on said mobile frame and operative to receive tobacco leaves defoliated by said defoliator assembly and to convey the defoliated leaves to a collection area operatively associated with said harvester; and

an automatic hydraulic speed control system operatively connected to said defoliator drive means for automatically and continuously controlling and maintaining the speed of said defoliator assembly at a speed which is a fixed ratio with respect to the ground speed of said harvester, said automatic hydraulic speed control means comprising a hydraulic pump means operatively connected to said defoliator hydraulic drive motor of said defoliator drive means for fluidly driving the same and consequently driving the same and consequently driving said leaf defoliator assembly;

a hydraulic motor means operatively connected to said hydraulic wheel drive system and hydraulically driven thereby only when at least one wheel of said ground engaging wheel means is driven by said hydraulic wheel drive system, said hydraulic wheel drive system being effective to automatically drive said hydraulic motor means at various speeds proportional to the ground speed of said harvester, and said hydraulic motor means being drivingly interconnected to said hydraulic pump means for driving the same at the speed corresponding to its driven speed and in a fixed ratio to the ground speed of said harvester; and

means for varying the fluid output of said hydraulic pump means independently of the driven speed thereof for synchronizing the average rearward horizontal speed of each defoliating element with the forward ground speed of said harvester such that during leaf defoliation respective defoliating elements move at an average horizontal and rearward speed that approximates the general forward ground speed of said harvester irrespective of the speed of the harvester or changes therein during the harvesting operation.

7. A tobacco harvester having an automatic hydraulic speed control system for automatically varying and continuously controlling and maintaining the operating speed of a leaf defoliator assembly relative to and in proportion to the ground speed of said harvester, comprising in combination:

a wheel supported mobile frame structure adapted to move through a tobacco field;

a leaf defoliator assembly mounted on said mobile frame and having a plurality of laterally spaced defoliating elements adapted during leaf defoliation to extend transversely between successive stalks and wherein adjacent pairs of said defoliating elements closely surround portions of each stalk and move vertically up the stalk to effectuate defoliation and rearwardly therewith due to a horizontal and rearward component as the stalk passes through the defoliator assembly;

a leaf conveyor assembly disposed on said mobile frame and operative to receive tobacco leaves defoliated by said defoliator assembly and to carry the defoliated leaves to a collection area operatively associated with said harvester;

hydraulic drive means operatively connected to said defoliator assembly for driving the defoliator assembly as said tobacco harvester moves through the field;

a hydraulic speed control unit operatively connected to a source of hydraulic fluid and including a hydraulic pump means for driving said hydraulic drive means and the defoliator assembly operatively connected thereto;

said hydraulic speed control unit having means operatively associated therewith and automatically and continuously responsive to the ground speed of said harvester and variations therein for automatically and continuously driving said hydraulic pump means at a speed proportional to said harvester ground speed and thereby directing a system of fluid with a volumetric flow rate generally proportional to the ground speed of said harvester from said hydraulic speed control unit to said hydraulic defoliator drive means for continuously driving said defoliator assembly at a speed generally proportional to the ground speed of said harvester such that the speed of said defoliator assembly is continuously controlled and maintained at a speed proportional to the ground speed of said tobacco harvester irrespective of changes in the harvester ground speed as it moves through the field;

said hydraulic pump means of said hydraulic speed control unit further including adjustable flow control means for varying and adjusting the volumetric flow of said fluid from said hydraulic speed control unit independently of said harvester ground speed and independently of the driven speed of said hydraulic pump means, and for consequently varying and adjusting the average horizontal and rearward speed of the defoliating elements of said defoliator assembly during leaf defoliation to generally equal the forward ground speed of said harvester such that the average horizontal and rearward speed of said defoliating elements during leaf defoliation is continuously generally equal to the forward ground speed of said harvester and varies in a proportional relationship therewith.

8. A tobacco harvester having an automatic hydraulic speed control system for continuously controlling and maintaining the operating speed of a tobacco leaf defoliator assembly relative to and in proportion to the ground speed of said tobacco harvester, said harvester and control system comprising in combination:

a. a mobile frame adapted to move through a tobacco field during a tobacco harvesting operation;

b. ground engaging wheel means rotatively mounted to said mobile frame;

c. a hydraulic wheel drive system disposed on said harvester and operative to drive said ground engaging wheel means;

d. a tobacco leaf defoliator assembly mounted on said mobile frame and including a pair of defoliator units disposed in lateral spaced apart relationship so as to permit passage of tobacco stalks therebetween as said harvester moves through the field, at least one of said defoliating units including a plurality of members with each member having a series of spaced apart leaf defoliating elements fixed thereto and extending therefrom, said members being mounted for cyclic movement about an endless path that may be generally described in part at least as including movement inwardly toward respective stalks of the row being harvested to where the leaf defoliating elements project into the plane of the stalk row between respective stalks passing between the defoliating units, vertical leaf defoliating movement with a horizontal and rearward component that enables respective defoliating elements to be maintained generally parallel to the axis of the particular stalks passing adjacent thereto as the harvester moves forwardly wherein the defoliating elements act to engage and defoliate leaves from the respective tobacco stalks as they move vertically adjacent the stalks, and outward movement retracting said members and the defoliating elements associated therewith from the respective tobacco stalks;

e. defoliator drive means for driving said defoliator assembly and including a defoliator hydraulic drive motor operatively connected to said defoliator assembly for driving the same;

f. a leaf conveyor assembly disposed on said mobile frame and operative to receive tobacco leaves defoliated by said defoliator assembly and to carry the defoliated leaves to a collection area operatively associated with said harvester; and

g. an automatic hydraulic speed control system operatively connected to said defoliator drive means for continuously controlling and maintaining the speed of said defoliator assembly at a speed proportional to the ground speed of said harvester, said automatic hydraulic speed control system comprising;

1. a hydraulic drive motor means operatively connected into said hydraulic wheel drive system and driven thereby only when said ground engaging wheel means of said harvester is driven;

9. a hydraulic pump means operatively connected to said hydraulic motor means of said hydraulic speed control system and driven thereby only when said ground engaging wheel means is driven by said hydraulic wheel drive system, said hydraulic pump means being also operatively connected to a source of hydraulic fluid and adapted when driven to produce an output flow of fluid out of an output port formed therein;

3. means interconnecting said output port of said hydraulic pump means with said defoliator hydraulic motor of said defoliator drive means wherein the output fluid of said hydraulic pump means drives said defoliator hydraulic motor which in turn is operative to drive said defoliator assembly; and

4. means for automatically varying and adjusting the speed of said defoliator assembly such that the rearward speed of each defoliating element during the defoliating portion of the movement cycle is approximately equal to the forward ground speed of said harvester, and as such it follows that any two defoliating elements that partially surround a respective stalk passing between the defoliating units remain generally parallel to the axis of the stalk and moves rearwardly therewith as the stalk passes between said defoliating units, said means for automatically varying and adjusting the speed of said defoliator assembly including means for varying the fluid output of said hydraulic pump means independently of the driven speed thereof and consequently driving said defoliator hydraulic motor at a speed that will result in a direct and approximate one-to-one speed relationship between the rearward speed of each defoliating element and the forward ground speed of said harvester.