MXPA01003472A - Liftable wheel unit for agricultural implement frame - Google Patents

Abstract

Lift wheel structure for an implement includes four bar linkage having a curved lower link connected to the frame closely adjacent a first tool-carrying rank. A caster wheel is supported at the forward end of the linkage for castering in an accommodation area defined by the curved lower link. Plates are bolted to the sides of the lower link and extend along sides of an upper link to a connection with a lift cylinder above the upper link. The link and the cylinder closely overlie the frame to limit interference with other components mound above the frame and facilitate the compact folding of implement section. Loads, including cylinder lift loads, are transmitted primarily through the lower link. A protected transducer assembly is connected between the lower link and the frame to maximize and linearized transducer response in the depth control range. The lift wheel structure can be mounted at different location on the frame to accommodate different tool configurations and provide the desired automatic depth control and levelling functions. In one embodiment a tension link connects a forward four bar linkage wheel structure with a rear single pivot lift wheel structure such that level lift is provided.

Description

AGRICULTURAL IMPLEMENT LIFTING WHEEL STRUCTURE 1) Field of the Invention: The present invention relates generally to agricultural implements and, more specifically, to the lifting wheel structure for an implement frame. 2) Related Art: Implements such as chisel plows and field cultivators in the past have used wheel hoists connected to a set of rock shaft in the main frame. The rock shaft assembly is expensive and bulky and often interferes with the placement of implement tools in the desired location on the frame. As a result of permanently assembled lift assembly components, the versatility of the implement is compromised and the number of available tool spaces is small. A long tube is required to avoid excessive entanglement and adds weight to the back of the implement. A compression link operably connects the lifting wheels of the rock shaft with front wheels to maintain the level of the implement over a range of vertically adjusted positions. The compression link must be strong to avoid bending under compression loads and therefore increase costs and add more weight to the back of the implement. The change in center of gravity makes the implement heavy at the rear so the front of the frame rises, especially if traditional tools are held from the back of the implement. For many lifting wheel configurations, the hydraulic cylinders and brackets are located behind the center of gravity of the implement, further increasing the rear weight distribution.

Front lift wheel assemblies often include four-bar joints that have an upper bar connected to the compression joint and a lower bar which is loaded by the weight of the implement and by any additional low forces by the tools that are pulled on the ground during work operations in the field. Both bars have to be relatively heavy to handle the respective loads of the lifting cylinder and the weight of the implement. Many of the currently available lifting wheel assemblies include connecting and cylinder links which are displaced a substantial distance above the frame and cause interference problems when the outer wing sections are bent over the frame for transport. The joints in the wing sections can also cause interference problems in implements such as five-section machines where the outer and inner wings on each side are pivoted in close proximity during transport. Wheel articulation structures on the back and front of an implement often have different configurations, and maintain the level of the implement in the longitudinal direction with the lifting wheels mechanically connected has been a continuing problem. Some lifting wheel assemblies, including those which move vertically by oscillating around a single pivot axis, require a considerable amount of space to extend longitudinally for their full range of vertical movement and additionally limit the placement of the tools in the implement frame. Implements which include an electronically controlled depth adjustment often fail to have a protected and convenient location for a potentiometer or other type of transducers located in or adjacent to the lift wheel assembly. The maximization and linearization movement of a transducer such as a rotary potentiometer in the field work position of the implement continues to be a problem.

BRIEF SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an improved lifting wheel structure for an implement. It is another object of the invention to provide such a lifting wheel structure which overcomes most or all of the aforementioned problems.

It is further an object of the present invention to provide a lifting wheel structure for an implement having a reduced profile so that interference problems are reduced. It is another object to provide such a structure which increases the suction of this tool space.

It is still another object of the present invention to provide a lifting wheel structure for an implement having an improved four-bar linkage. It is another object to provide such a structure which requires a relatively small longitudinal dimension for operation over the full range of vertically adjusted positions. It is further an object to provide such a structure where substantially all of the heavy load of the joint including the support and lifting loads is loaded by the lower joint. It is still another object to provide such an articulation which is closely supported adjacent the frame tube and which includes a curved lower link to provide a wheel accommodation space.

It is also an object to provide an improved lifting wheel structure which removes the rock shafts and which can be easily mounted in different locations in the frame. It is also an object to provide such a structure which provides a better weight distribution of the implement and reduces the weight at the rear of the implement. It is another object to provide such a structure which eliminates compression joints and allows the use of shorter frames.

A lifting wheel structure constructed in accordance with the teachings of the present invention includes a module type configuration which can be mounted at different locations along an implement frame. A four bar linkage including a curved lower link is connected to the frame closely adjacent to a first tool transport arrangement. A wheel moulder is held at the front end of the hinge to mold into an accommodation area defined by the curved lower hinge. The plates are bolted to the sides of the lower joint and extend along the sides of an upper joint to a connection with a lifting cylinder directly above the upper joint. The lifting cylinder is mounted on a support which has a front part connected to the rear arrangement adjacent to the first arrangement and a front end connected to a molder which pivotally connects the rear pivots of the four bar linkage to the first arrangement .

The plates extend upwards from the connection with the cylinder to a pivoted connection with a tension joint which extends in the longitudinal direction to a connection with a lifting wheel assembly which may be either an arrangement of four. bars similar to the lifting wheel structure described above or to a conventional single arm arrangement. The hinge and cylinder closely rest the frame to limit interference with other components mounted above the frame and to facilitate compact folding of the attachment sections. The construction eliminates heavy compression joints and provides a level lift. The removal of the rock shaft and the welded construction of the rock shaft greatly improves the versatility of assembly of the frame and tool component, and the same lifting structure module can be used for different implements.

The four bar linkage provides good vertical lift characteristics with a minimum amount of longitudinal space requirements for reduced frame length, improved waste flow and more versatility of this tool space. A full flotation hitch with lifting characteristics eliminates any need for a separate gear wheel that requires adjustment each time the depth is adjusted. Most of the articulation load including that made by the weight of the implement and the suction characteristics of the tool and the lifting load of the lifting cylinder is supported by the lower joint, and therefore the upper joint can be of a less expensive and lighter construction. By connecting the cylinder to the plates extending upwards from the lower joint, the moment arm suitable for the cylinder and the arm length necessary for proper rear and front wheel movement are provided without a substantial projection of the components from the assembly to the top of the frame. The accommodation space of the wheel opens in the forward direction of the rotation of the rim so that the mud is scraped off the wheel and is not wedged between the top and the wheel of the curved joint. The rear pivot assembly of the four-bar link provides a protected space for the rod that connects the wheel position transducer to the lower link. The transducer rod is connected at a point where it is above the path arc above the lower link pivot to maximize longitudinal linear movement in the range of field work of the lifting wheel. Without the full flotation hitch, the operator may have to have a gear wheel. If this is the case, the operator will then be required to adjust (manually) the gear wheel each time he adjusts the depth.

These and other objects, features and advantages of the present invention may be apparent to one of skill in the art upon reading the following detailed description in view of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front perspective view of a partially unfolded multi-section implement frame with the lifting system of the present invention attached thereto.

Figure 2 is a side view of the lifting wheel structure used in the wing frame of the implement frame of Figure 1 showing the wheels lowered relative to the frame for transport.

Figure 3 is a side view similar to that of Figure 2 but showing the elevated wheels relative to the frame for operation in the field.

Figure 4 is a top view of the lifting wheel structure of Figure 3.

Figure 5 is an enlarged side view of the connection area of the lifting wheel assembly to the front of the frame and showing the details of the assembly of the transducer assembly.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to Figure 1, there is shown a multi-section attachment 10, such as a chisel plow or a field cultivator, with the ground work tools removed. The implement 10- as shown includes a central main frame 12 having a front hook connection structure 14 adapted for the connection of a tow vehicle by means of a catch (not shown) for movement in the front direction F. The frame 12 includes tubes that extend transversely rear and front 16 and 18 and centrally extending tubes 22 and 24 connected by central longitudinally extending arms 26 and 28 and outer end arms 32 and 34. The left and right lifting wheel structures 36 and 38 support on frame 12 above the ground and move the frame vertically between a raised transport position (shown) and in a lowered fieldwork position.

The implement 10 includes left and right wing sections 42 and 44 having innermost ends hinged to the outer arms 32 and 34, respectively, to oscillate between an outwardly extending fieldwork position and a transport position bent by wing fold structures 46 and 48 connected to the tube 22 and the respective wing sections 42 and 44. A protrusion stop assembly 49 is also connected to the frame 12 and helps to support the wing sections 42 and 44 for their positions completely bent The wing sections 42 and 44 are generally mirror images of one another and include rear and front tubes 50 and 52 connected by the longitudinally extending arms as shown in 54, 56 and 58. The central tool transport tubes 62 and 64 extend transversely between the arms 54 and 56 as shown in Figure 1. The lifting wheel structures 66 and 68 are connected near the outer ends of the wing section 42 and 44 for operation generally in unison with the lifting wheel structures 36 and 38 for raising and lowering the wing sections with the main frame 12. The construction of the lifting wheel structures 36 and 38 is substantially similar to that of the lifting wheel structures 66 and 68 with the exception of the offset distance of the longitudinally extending joints of the frame for structures 66 and 68 is larger to accommodate the structures bent 46 and 48 right there underneath. Therefore, only structure 68 will be described in detail below.

The lift wheel structure 68 includes a four-bar link assembly cast wheel assembly 70 and a single rear pivot lift wheel assembly 72 connected for operation in unison by the link structure 74. Although a set of Single pivot is shown with the number 72, it is to be understood that a joint type assembly of four bars and generally identical to 70 can be used in place of the single pivot assembly. The simple pivot assembly 72 is less expensive and when it is connected as described below it provides lowering and lifting characteristics closely parallel to that of the assembly 70 so that the implement frame generally remains level from back to front while the sets of wheel move vertically relative to the frame.

The wheel assembly 70 includes a vertical mounting bracket 80 connected by a U-bolt 82 to the front tube 50. The rear ends of the longitudinally extending lower and upper articulations 86 and 88 are pivotally connected to the bracket 80 in vertically offset locations 90 and 92 immediately forward of the front face of the tube 50. The forward ends of the links 86 and 88 are pivotally connected in vertically offset locations 96 and 98 at the rear end of the moulder 100. The forward end of the moulder 100 includes a pivot 102 supporting a shaping arm 104 when oscillating about a vertical axis. Shaping arm 104 extends inwardly from pivot 102 curves back and down about one side of a wheel 106 to a connection with hub 108 of the wheel.

As best seen in Figure 3, the lower link 88 is curved and opens down above the wheel 106 to accommodate molding when the implement is in the lowered position. The space between the outer circumference of the wheel 106 and the bottom of the articulation 88 is slightly increased in the direction of rotation R of the wheel so that the adjacent area of the mounting bracket 80 tends to scrape the mud and debris that can accumulate in the wheel 106 in wet conditions and the increased space prevents coining of the remaining material between the wheel and the articulation 88. The lift wheel joint 68 is designed so that the primary load of the four-bar linkage is through of the lower articulation 38, with the upper articulation maintaining a vertical orientation that generally of the molding axis.

A pair of transversely spaced plates 110 are bolted to the central part of the lower link 88 and extend upward on either side of the upper link 86. The plates 110 oscillate with the lower link 88 and facilitate movement of the upper link 86. between the plates while the wheel assembly 70 moves vertically. A rear center part of the plates 110 is connected to the mounting assembly of the end of the cylinder rod 116 just above the link 86. The plates 110 extend up and back from the central part to a joint collection 118 located directly from the assembly 116 when the lifting wheel structure 68 is in the transport position (figures 1 and 2) and in the rear form of the assembly 116 when the lifting wheel structure 68 is in the field work position shown in FIG. figure 3 The upper part of the bracket 80 is connected to a second bracket 120 which extends rearwardly on the tube 50 and then back and down towards a connection with the front face of the tube 62 by means of a bolt bracket in the form of U 122. A mounting part of the cylinder 124 extends upwardly from a rear part of the bracket 122 and supports the base end of a lifting cylinder 130. The rod end of the cylinder 130 is connected to the mounting assembly of the cylinder 122. rod end 116. Extending the cylinder (figure 2) pivots the lower link 88 downwardly around the location 92, while retracting the cylinder (figure 3) pivots the joint 88 upwards. As can be seen from FIGS. 2 and 3, the cylinder 130 extends generally parallel to and is offset only slightly above the section of the frame to which it is fastened in the end positions shown as well as in the intermediate positions to provide a very tight arrangement. compact. By securing the cylinder 130 to the lower link 88 by means of the plates 110, the necessary phase shift for the arm is provided without raising the assembly 116 substantially above the upper link 86. Also, the upshift of the hinge connection 118 relative to the frame is minimized, and the curved configuration of the rear edges of the plates 110 provides a compact configuration of the plates 110, the cylinder 130 and the hinge structure 74 in the field work position ( figure 3).

The lifting wheel assembly 72 includes a bracket 140 connected to the rear tube 52. The bracket 140 pivotably supports a wheel arm 144 to oscillate about a pivot at the location 146 located downstream and forward of the front face of the tube 52 The wheel arm 144 extends downwardly and forwardly (Fig. 2) to a hub 148 mounted to the rear wheel 150 to rotate about a transverse axis. A pair of plates 156 are bolted to the sides of the wheel arm 144 and extend up and forward (Figure 2) to an upper end 158 located above and forward of the tube 52 and generally at the same distance above the corresponding frame. as in the connection of the joint 118 of the plates 110. An adjustable longitudinal tension joint 160 extends between the connection 118 and the upper end 158 and restricts the operation of the lifting wheel structures 70 and 72 generally in unison. In both end positions and at any point therebetween, the frame 160 closely rests the cylinder 130 and is offset only a short distance above the frame. The hinge 160 '(FIG. 1) is offset above the frame 12 by the plates 110' and 116 'which are slightly higher than the corresponding plates 110 and 116 in the wing sections to provide the necessary space for the structures wing fold 46 and 48.

A transducer assembly 170 (FIG. 5) is connected between the second bracket 120 and the lower link 88 to provide feedback for an automatic depth control mechanism which may be generally of the type shown in the commonly assigned United States of America patent. No. 5,957,218. The assembly 170 includes a rotary potentiometer 172 having an arm 174 with a distal end 176 movable through an arc indicated at 178. The distal end 176 is connected by a hinge 180 to a connection with the lower hinge 88 by a pivot in 184 slightly offset forwards and above the pivot axis at location 92. The link 180 extends between opposite sides of the bracket 80 for protection. The pivot 184 moves through an arc 188 while the lower articulation 88 is pivoted from the transport position (shown) in the right to left direction to the fully raised position. The points 176 and 184 are thus located that the arches 178 and 188 are generally centered above the positions on the central center to maximize and linearize the movement of the transducer in the operating positions during the operations of the field. The configuration described above also protects the transducer assembly 170 since the components of the transducer are closely surrounded but out of phase with the larger components in the implement. The potentiometer 172 provides a wheel position signal to the depth control mechanism so that the position of the wheel and the depth of penetration of the tool can be selected and maintained automatically. If independent control of the rear and front wheel is desired, the wheel assembly 72 and the link 74 can be replaced with a wheel assembly generally identical to the wheel assembly 70 and individually controlled with the controller. The mounting configuration for the assembly 70 provides versatility for mounting the lifting wheel structure in different locations on the frame to accommodate desired tool space in the tubes.

Having described the preferred embodiment, it will be apparent that various modifications can be made without departing from the scope of the invention as defined in the appended claims.

Claims (14)

R E I V I N D I C A C I O N S

1. A lifting wheel assembly for the frame of an agricultural implement adapted for forward movement on the ground, the lifting wheel assembly comprises: an assembly adapted for connecting the frame; a four bar linkage including a top link and an inner link, the links have proximally pivotally connected ends connected to the assembly at vertically offset first pivot locations, and distal ends; a wheel assembly pivotally connected to the distal ends of the joints in second vertically offset locations; a geared wheel to earth connected to the wheel assembly; a lifting arm fixed to the lower joint extending upwardly adjacent to the upper joint to an upper end portion above the upper joint; and a motor connected to the upper end portion and operable to pivot the lower link between a transport position and a field work position, so that substantially all of the load between the wheel during motor operation is transmitted through the motor. lower joint.

2. The lifting assembly, as claimed in clause 1, characterized in that the lower joint comprises a member opening curved downwardly away from the upper joint and defines a wheel accommodation space below the four-bar joint.

3. The lifting assembly, as claimed in clause 2, characterized in that the curved member includes a central part connected to the lifting arm at an out-of-phase connection location above a connection line of the first and second location lines of pivot of the lower joint.

4. The lifting assembly, as claimed in clause 1, characterized in that the assembly includes a cylinder support structure, and the motor comprises a retracting and extensible cylinder connected to the cylinder support.

5. The lifting assembly, as claimed in clause 1, characterized in that it includes a second of wheel offset in the longitudinal direction from the gear wheel to ground and vertically pivoted, a wheel articulation extending upwards from the second wheel to pivot with the wheel, a longitudinal tension joint connecting the wheel articulation and the lifting arm.

6. The lifting assembly, as claimed in clause 5, characterized in that a four-bar link connects the second wheel to the frame.

7. The lifting assembly, as claimed in clause 5, characterized in that it includes a simple wheel arm pivotably connected to the frame of the frame and supports the second wheel to pivot vertically about a transverse axis in the forward direction.

8. The lifting assembly, as claimed in clause 2, characterized in that it is slowly wheel accommodating is curved in an arc complementary to a circumference of the gear wheel to ground and is offset from the gear wheel to ground, the ground gear wheel has a forward direction to rotate, and wherein the distance of phase shift increases in the turning direction of the wheel to prevent earth and debris from being housed between the ground gear wheel and the joint lower.

9. The lifting assembly, as claimed in clause 1, characterized in that the assembly includes a bracket that extends upwards from the frame, a connection member having a front end connected to the bracket, the rear end connected to the bracket, cylinder and supporting the cylinder in a relationship generally parallel to the frame directly above the frame and below the upper end portion of the lifting arm.

10. The lifting assembly, as claimed in clause 1, characterized in that the lifting arm comprises a pair of spaced plates connected on opposite sides of the lower link and extending upward on opposite sides of the upper link.

11. The lifting assembly, as claimed in clause 1, characterized in that it also comprises a transducer assembly connected between the frame and the lower articulation to provide a position indication of the gear wheel to ground relative to the frame.

12. The lifting assembly, as claimed in clause 11, characterized in that it includes a collection of transducer in the lower articulation rotatable with the lower articulation about an arc which is centered above the pivot location for the lower articulation for maximize the movement of the linearized transducer and provide protection for the transducer.

13. The lifting assembly, as claimed in clause 4, characterized in that the cylinder remains generally horizontal during extension and retraction.

14. The lifting assembly, as claimed in clause 13, characterized in that it includes a second connected wheel still had transverse, the second wheel phase shift in the longitudinal direction from the gear wheel to ground and pivotally vertical, a wheel articulation which extends upwards from the second wheel to pivot with the wheel, and the longitudinal tension joint connecting the wheel articulation and the lifting arm, wherein the tension joint and the cylinder rest closely adjacent to each other and they remain generally parallel with one another over a range of operation. SUMMARY A lifting wheel structure for an implement that includes a four-bar linkage having a curved lower link connected to the frame closely adjacent to a first tool transport arrangement. A shaping wheel is held at the front end of the hinge to mold into an accommodation area defined by the curved lower hinge. The plates are bolted to the sides of the lower joint and extend along the sides of an upper joint to a connection with the lifting cylinder directly above the upper joint. The hinge and cylinder closely support the frame to limit interference with other components mounted above the frame and to facilitate compact folding of the attachment sections. The loads, including the lifting loads of the cylinder, are transmitted primarily and through the lower joint. A protected transducer assembly is connected between the lower link and the frame to maximize and linearize the response of the transducer in the range of depth control. The lifting wheel structure can be mounted in different locations on the frame to accommodate different tool configurations and provide the desired automatic depth control and leveling functions. In one embodiment a tension joint connects a four-bar articulation wheel structure with a single-pivot rear lifting wheel structure such that leveling is provided.