FIELD OF THE INVENTION

The present invention relates to ground-engaging farm implements, and more particularly, to ground-engaging farm implements having air or spring suspension.

BACKGROUND OF THE INVENTION

In present-day farming, a large variety of ground-engaging farm implements such as, for example, plows, harrows, tillers, etc., are employed for cultivating agricultural land. As farm sizes grow and agricultural competitiveness increases, operational efficiency of the work done for cultivating the agricultural land becomes increasingly important. Large present-day farm implements, towed by powerful power units, enable a single operator to cover many acres of land per hour.

Unfortunately, with increasing size of the ground-engaging farm implements and increasing speed of operating the same, the lack of suspension of present-day ground- engaging farm implements results, when encountering un-even ground, reduced consistency of the ground contact of the ground-engaging tool, increasing wear of the farm implement and the hitch, as well as decreasing the operator comfort. It is desirable to provide a ground-engaging farm implement having an air or spring suspension that substantially increases the consistency of the ground contact of the ground-engaging tool when encountering un-even ground.

It is also desirable to provide a ground-engaging farm implement having an air or spring suspension that enables increased speed of operation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ground-engaging farm implement having an air or spring suspension that substantially increases the consistency of the ground contact of the ground- engaging tool when encountering un-even ground.

Another object of the present invention is to provide a ground-engaging farm implement having an air or spring suspension that enables increased speed of operation.

According to one aspect of the present invention, there is provided a ground-engaging farm implement. A support frame of the ground-engaging farm implement has a front end portion which is adapted for being coupled to a hitch of a power unit. At least one ground-engaging tool is mounted to the support frame. A substantial portion of the weight of the farm implement is supported by at least one support wheel. A wheel support structure having the at least one support wheel rotatably movable mounted thereto is pivotally movable mounted to the support frame such that the at least one support wheel is enabled to substantially vertically move a predetermined distance with respect to the support frame. A suspension air bag of an air suspension system is interposed between the support frame and the wheel support structure for controlling the vertical movement of the at least one support wheel.

An advantage of the present invention is that it provides a ground-engaging farm implement having an air or spring suspension that substantially increases the consistency of the ground contact of the ground-engaging tool when encountering un-even ground.

A further advantage of the present invention is that it provides a ground-engaging farm implement having an air or spring suspension that enables increased speed of operation.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention is described below with reference to the accompanying drawings, in which:

Figure l a is a simplified block diagram illustrating a perspective top view of a ground-engaging farm implement according to a preferred embodiment of the invention;

Figure lb is a simplified block diagram illustrating a perspective top view of a centre portion of the ground-engaging farm implement according to a preferred embodiment of the invention;

Figure l c is a simplified block diagram illustrating a perspective bottom view of a suspension of the ground-engaging farm implement according to a preferred embodiment of the invention;

Figure I d is a simplified block diagram illustrating a perspective side view of a walking wheel arrangement of the ground-engaging farm implement according to a preferred embodiment of the invention;

Figure 1 e is a simplified block diagram illustrating main components of an air suspension system employed in the ground-engaging farm implement according to a preferred embodiment of the invention; Figures If and lg are simplified block diagrams illustrating in sectional side views modes of operation of the air suspension of the ground-engaging farm implement according to a preferred embodiment of the invention; and,

Figures 2a to 2c are simplified block diagrams illustrating in top views alternative embodiments of wheel support structures of the ground-engaging farm implement according to a preferred embodiment of the invention.

DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are now described.

While the description of the preferred embodiments hereinbelow is with reference to a tiller having a centre frame supported by two wheels, it will become evident to those skilled in the art that the embodiments of the invention are not limited thereto, but are also adaptable for use with various other ground-engaging farm implements such as, for example, plows, harrows, tillers, etc. Furthermore, the embodiments of the invention are also adaptable to ground-engaging farm implements having a different number of wheels supporting the centre frame.

It is noted that, while the preferred embodiments employ air suspension, other types of suspension may also be employed such as, for example, coil spring suspension, leaf spring suspension, torsion beam suspension, or hydro-pneumatic suspension.

Referring to Figures la to lg, a ground-engaging farm implement 100 according to a preferred embodiment of the invention is provided. Support frame 102 of the ground- engaging farm implement 100 has a front end portion 102A which is adapted - coupler

102B - for being coupled to a hitch of a power unit (not shown) or other heavy equipment such as, for example, a bulldozer. In operation, the power unit tows the ground-engaging farm implement 100 in a forward direction, as indicated by the large block arrow in Figures la and lb. A ground-engaging tool such as, for example, tines 1 10 of a tiller, as illustrated in Figures la to Id, are mounted to the support frame 102 and extension wings 106A and 106B. The extension wings 106A and 106B are pivotally movable mounted to the support frame 102 in order to enable folding of the same for storage and transport of the ground-engaging farm implement 100. The support frame 102 is supported by support wheels 104A and 104B such that a substantial portion of the weight of the farm implement is carried by the support wheels 104A and 104B.

The support wheels 104A and 104B are rotatably movable - about axis 105 - mounted to wheel support structure 120A, 120B, 120C in a conventional manner, as illustrated in Figure lc. The wheel support structure, preferably, comprises a wheel connecting element 120C oriented parallel to the axis of rotation 105 of the support wheels 104A and 104B and two mounting arms 120A and 120B fixedly connected, for example, welded, to the wheel connecting element 120C and oriented substantially perpendicular thereto. The wheel support structure 120A, 120B, 120C is pivotally movable - about axis 123 - mounted to the support frame 102 at pivots 122A and 122B in a conventional manner using, for example, a bolt accommodated in respective bores disposed in the wheel support structure and U-shaped mounting elements welded to the centre frame 102. Preferably, the pivots 122A and 122B are placed between the axis of rotation 105 of the support wheels 104A and 104B and the front end portion 102A of the support frame 102. The pivotally movable mounted wheel support structure 120A, 120B, 120C enables the support wheels 104A and 104B to substantially vertically move a predetermined distance with respect to the support frame 102 when encountering un-even ground, as indicated by the block arrows in Figures lb and lc.

Preferably, the support frame 102, the extension wings 106A and 106B, and the wheel support structure 120A, 120B, 120C are made using rectangular Hollow Structural Sections (HSS) of steel which are connected using conventional welding techniques. The hub of each of the support wheels 104A and 104B is mounted to the wheel connecting element 120C via a conventional combination of an axle and an off-the-shelf bearing. Suspension air bags 124A and 124B of an air suspension system are interposed between the support frame 102 and the wheel support structure 120A, 120B, 120C for controlling the vertical movement of the support wheels 104A and 104B. Preferably, each of the mounting arms 120A and 120B is placed in proximity to a respective support wheel 104A, 104B and the suspension air bagsl24A and 124B are placed in proximity to the respective mounting arm 120A, 120B.

In operation, the un-folded extension wings 106A and 106B are supported by walking wheel arrangements 108A and 108B, as illustrated in Figures la and Id. Preferably, each walking wheel arrangement 108A, 108B comprises a front walking wheel 130A, 130B and a rear walking wheel 132A, 132B rotatably mounted - about axis 131, 133, respectively - to wheel support beam 134A, 134B, which is pivotally movable - about axis 137 oriented parallel to the axes 131 and 133 - mounted at pivot 136A, 136B. The pivotally movable mounted wheel support beam 134A, 134B enables up/down movement of the walking wheels about the axis 137 when encountering un-even ground, thus reducing the "jumping" effect on the extension wings 106A and 106B. During storage and transport, the walking wheel arrangements 108A and 108B are folded upwardly by rotating the same about axis 139 using respective hydraulic cylinders 140A and 140B connected to lever mechanisms 138A, 142A and 138B, 142B.

Preferably, the air suspension system employed in the ground-engaging farm implement 100 is an off-the-shelf air suspension system chosen from a large variety of commercially available air suspension systems depending on, for example, the type and weight of the ground-engaging farm implement 100 and the desired complexity of functions to be performed by the air suspension system. Referring to Figure le, the main components of the air suspension system employed in the ground-engaging farm implement 100 are: air compressor unit 150 providing compressed air to the suspension air bags 124A and 124B via compressed air lines 151 ; and, controller 156 connected to the air compressor unit 150 and solenoid vales 152A, 152B of the respective suspension air bags 124A, 124B via control lines 157.

The air compressor unit 150 comprises, for example, a conventional air compressor driven by an electric motor connected to the electrical system of the power unit - typically 12V DC - via power line 153 and coupler 154. Alternatively, the air compressor driven by a hydraulic drive connected to the hydraulic system of the power unit.

Controller 156 is, for example, a computer comprising a processor for executing commands stored in a non-volatile storage medium to determine control commands in dependence upon sensor signals received from pressure sensors and ride-height sensors (not shown) and to provide the same to the air compressor unit 150 and the solenoid vales 152A, 152B. The controller 156 is powered by the electrical system of the power unit - typically 12V DC - via power line 159 and coupler 158.

In operation, the controller 156 controls the substantially vertical movement of the support wheels 104A, 104B when encountering un-even ground within a predetermined distance D, as illustrated in Figure If. Optionally, the controller 156 also controls adjustment of the air suspension to provide a predetermined level height of the support frame 102 above ground 10 in a predetermined range between a minimum level height HLmin and a maximum level height HLmax, as illustrated in Figure l g.

Further optionally, the controller 156 comprises a user interface such as, for example, a touch screen to enable the operator to select a desired mode of operation of the air suspension system such as, for example, stiffness of the suspension, predetermined distance D, and level height HL of the support frame 102 above ground.

The employment of the air suspension system in the ground-engaging farm implement 100, as illustrated hereinabove, substantially improves the ride of the same, particularly, when encountering un-even ground, thus substantially reducing jumping and

consequently substantially increasing the consistency of the ground contact of the ground-engaging tool 1 10. Substantially reduced jumping enables operation of the ground-engaging farm implement 100 at an increased speed compared to a ground- engaging farm implement absent air suspension. The employment of the air suspension system in the ground-engaging farm implement 100 also enables additional functionalities such as, for example, adjustment of the stiffness of the suspension, predetermined distance D, and level height HL of the support frame 102 above ground in dependence upon the ground conditions and the mode of operation of the ground-engaging farm implement 100 such as depth of ground engagement of the ground-engaging tool.

Preferably, the components of the air suspension system are mounted to the support frame 102 in a conventional manner. For example, the suspension air bags 124A and 124B are mounted to the support frame 102 and the wheel support structure 120A, 120B, 120C using bolts.

The suspension of the support wheels 104A, 104B of the ground-engaging farm implement 100 described hereinabove suspends the support wheels 104A, 104B in a dependent manner, i.e. the support wheels 104A, 104B are rigidly connected to each other via wheel connecting element 120C. Therefore, when one support wheel encounters un-even ground it also causes the other support wheel to move in a substantially vertical direction.

In an alternative embodiment, as illustrated in Figure 2a, the wheel connecting element 120C is omitted and each support wheel 104A, 104B is directly mounted to a respective mounting arm 220A, 220B, resulting in an independent suspension of the support wheels 104A and 104B enabling each of the support wheels 104A and 104B to follow the ground independent from the other. Further alternatively, as illustrated in Figure 2b, mounting arms 320A and 320B are pivotally movable mounted to the support frame 102 at pivots 322A and 322B, having respective axes of rotation 323A and 323B oriented perpendicular to the axis of rotation 105 of the support wheels 104A and 104B.

In a further alternative embodiment the support frame 102 is supported by more than two support wheels, for example, four support wheels 404A.1 , 404A.2, 404B.1 , and 404B.2, as illustrated in Figure 2c. Here, each mounting arm 220A, 220B has two support wheels mounted thereto.

The provision of cushioning suspension on the axles or ground support and we will support structure of a farm implement such as this allows for more consistent ground contact of the ground engaging tools on the implement, as well as allowing by virtue of its ability to cushion the movement of the structure in relation to the ground for increased ground speed of the implement.

The present invention has been described herein with regard to preferred embodiments. However, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described herein.