Implement Frame Construction Including Tube Within a Tube

1) Field of the Invention

The present invention relates generally to agricultural implements and, more specifically, to a tube frame construction for an implement such as a chisel plow or field cultivator.

2) Related Art

Frames for implements such as field cultivators or chisel plows are typically fabricated by welding a series of similar size tubes together. In some frame fabrication methods, such as shown in U.S. Pat. No. 5,190,207, the end of one tube is laser cut to conform to the shape of the adjoining tube. The cut provides a solid connection by wrapping a portion of the cut tube end around the radius of the adjoining tube, and a shortened weld time is achieved. However, the joint can be expensive compared to a straight joint. Straight cut joints sometimes require filler rods during the weld process and often fail to provide the joint strength and integrity necessary for the heavy loading present during field operations of the implement. The frame sections often are made up of numerous short tube lengths with joint strength relying on the weld. If a weld joint is made improperly, the frame can fail. Further, painting operations often require drain holes in the welded tube members and add extra steps to the frame fabrication process. Numerous gussets are usually required, which add extra welding steps and present paint collection and drip problems during painting operations.

In some agricultural frame constructions, the end of one tube is welded to the side of another tube having a greater dimension (i.e., a tube that is 4.times.4 inches is welded to the 5 inch face of a 2.times.5 inch tube). While this joint usually can be formed with a simple fillet weld, the larger wall is prone to flex ("oil canning") due to the loading of the tube welded thereto. The mating tube is attached to the larger wall by a weld joint only, and the wall can deflect under the heavy bending and torsional loads encountered in the field. This deflection greatly reduces fatigue life of the joint. When hinge brackets or the like are attached, the bolts holding the brackets can collapse the wall of the attaching tube. Holding the bolt torque required to maintain joint strength becomes difficult as a result of the wall collapse.

Frame construction often includes clamping or bolting hitch sub-frames to a main frame. The sub-frames transfer draft loads from the towing vehicle to the cross members of the main frame but are expensive to manufacture, ship and assemble. The hitch sub-frame construction often requires expensive connecting points on the main frame. As with any bolted or clamped joint arrangement, the structural integrity and draft load transfer to the cross members is sometimes compromised. A further problem with such an arrangement is that the sub-frame does not extend to the rear of the machine; therefore, adding a rear hitch becomes more difficult.

To provide continuous lateral rank or tube members, some manufacturers use a bridge structure to help transmit loads through the machine. Transversely extending tool-supporting tubes are welded between upper and lower smaller cross section tubes. The bridge structure usually has high weld costs, and many small welds rather than large continuous welds are used. Flare bevel groove welds are necessary and tend to have less structural integrity compared to a fillet weld. The joints tend to crack during combined bending and torsional loading.

It is therefore an object of the present invention to provide an improved frame construction for an agricultural implement. It is another object to provide such a frame construction which overcomes most or all of the aforementioned problems.

It is a further object to provide an improved frame construction for an agricultural implement which eliminates large numbers of short, welded tube sections and reduces or eliminates the need for gussets at tube intersections. It is yet another object to provide such a frame construction which reduces or eliminates tube wall problems at the tube joints caused by bending and torsional loading. It is another object to provide such a frame construction which has fewer parts and fewer problems with frame deformation and joint cracking than at least, most previously available frame constructions.

It is still another object to provide an agricultural frame construction having continuous transversely extending frame tubes without need for bridge structures or clamped or bolted sub-frame assemblies. It is a further object to provide such a construction having better joint and overall structural integrity and better resistance to parallelograming than most previously available frame constructions. It is another object to provide such a construction which provides improved hitch load distribution to lateral tubes.

It is another object to provide a frame construction for agricultural implements which simplifies weld fixturing and welding operations. It is another object to provide such a frame construction that is easier, faster and less costly to manufacture than most previously available frame constructions. It is another object to provide such a construction which advantageously uses holes and through-tubes to provide accurate and positive positioning of frame tubes.

It is another object to provide an implement frame construction having fewer weld start ups and more continuous welds at joints than at least, many previously available frame constructions. It is still a further object to provide such a construction which eliminates coping of joints, filler rods, and flare bevel groove joints. It is another object to provide such a construction which reduces flexing of sidewalls.

It is yet another object to provide an agricultural implement frame construction having an improved hinge area. It is a further object to provide such a construction which has better joint torque retention for a bolted hinge structure than at least most previously available constructions.

An implement frame construction includes a fore-and-aft extending tube having a cross section of first height with apertured sidewalls. Transversely extending tool-supporting tubes with cross section having a height less than the first height and matching the shape of the apertures are inserted through the apertures to provide a mechanical connection not solely reliant on joint weld strength. Bending rigidity is also increased over conventional frame construction since the aperture would have to distort for total joint failure. The apertures allow the transverse tubes to pass through the tube of larger height to eliminate or reduce sidewall flexing or "oil canning" of the larger tube. The resulting joint has more bending and torsional resistance than a butt-welded joint. The frame construction provides easily welded fillet welds on both sides of the larger dimension tube and reduces the number of gussets and the problems associated with gussets. The smaller tube runs continuously through the joint to reduce the number of components and welds necessary for a given frame configuration. Neither tube needs to be coped, and filler rods are eliminated since the fillet weld fills the gap between the larger dimension tube and the through-tube. The components themselves position the frame tubes relative to each other to simplify weld fixturing and increase resistance to parallelogramming.

Hinge areas are provided with increased torsional resistance by passing the smaller height tube through the larger dimension tube and welding the joint and locating the hinge at the joint. In one embodiment, the one sidewall of the larger dimension tube is apertured to receive the transverse tube, and the joint is welded. Hinge bolts pass through the sidewalls, and the welded joint prevents wall collapse to retain bolt torque. In another embodiment, both sidewalls of the larger dimension tube are apertured, the smaller tube passes through and is welded to both sides of the larger dimension tube for improved torsional rigidity and better joint torque retention. The smaller tube protrudes slightly from the outer sidewall, and the hinge is recessed to accept the protrusion and the weld.

Long, continuous fore-and-aft extending hitch tube members obviate hitch sub-frames and evenly distribute hitch loading to the lateral tubes independently of clamped or bolted joints and extensive gusseting. The continuous fore-and-aft members are incorporated into two main frame halves or sections so that sub-frame shipping and assembly are eliminated. Since the hitch tube members are continuous from the hitch to the rear of the machine, a rear hitch option can be added to allow the rear implement draft load to be efficiently transferred to the front hitch of the implement.

These and other objects, features and advantages of the present invention will become apparent from the detailed description below in view of the drawings.

FIG. 1 is a front perspective view of a portion of a main frame (half) section for an implement utilizing the frame construction of the present invention.

FIG. 2 is perspective view of a wing frame section for an implement.

FIG. 3 is an enlarged view of a joint on the wing frame section of FIG. 2 and illustrating the joint construction utilized for the frame sections of FIGS. 1 and 2.

FIG. 4 is an enlarged view of an end portion of an implement frame section showing a joint area for a hinge location.

FIG. 5 is a view of an end portion of an implement frame section showing an alternate embodiment of the joint area for a hinge location.

Referring now to FIG. 1, therein is shown a portion 10 of a main frame 12 for an implement such as a chisel plow or field cultivator adapted for towing in a forward direction F over the ground by a towing vehicle and hitch (not shown) connected to a forward hitch connector 14. Only the right-hand portion 10 (as viewed in the direction of travel F) of the frame 12 is shown since the left-hand portion has a similar tube within a tube construction and is generally a mirror image of the portion 10. A wing section 16 (FIG. 2) is adapted for support from the main frame 12 includes a tube within a tube construction of the type similar to that of the main frame 12. On the drawings, portions of the wing frame 16 are numbered identically to corresponding to portions of the main frame 12 but are distinguished by a prime after the number.

The main frame 12 includes a continuous fore-and-aft extending tubular member or main beam 22 having a rectangular cross section with first and second upright sidewalls 24 and 26 connected by top and bottom walls 28 and 30. The tubular member 22 has a generally rectangular cross section with the sidewalls 24 and 26 defining a preselected tube height which, as shown in FIG. 1, is greater than the tube width defined by the walls 28 and 30. On the main frame 12, the hitch connector 14 is apertured to conform to and receive the member 32 and is fixed to the forward end of the tubular member 22.

The main frame 12 includes transverse tubular members 32, 34, 36 and 38 having rectangular cross sections with front and rear walls 44 and 46 and top and bottom walls 48 and 50 walls spaced a distance apart which is less than the spacing between the top and bottom walls of the member 22. Both sidewalls 24 and 26 of the tubular member 22 are apertured at locations 52, 54, 56 and 58 and receive the corresponding tubular members 32-38. The apertures at 52-58 are generally vertically centered relative to the sidewalls and conform to the cross section of the corresponding members 32-38 to facilitate fabrication of the frame with minimal weld fixtures and provide mechanical support for the members to help resist torque loads and bending. Continuous fillet welds 60 (FIG. 3) at both walls around each aperture location fix the transverse tubular member to the walls 24 and 26 of the tubular member 22.

As shown in FIG. 1, the main frame 12 includes an inner fore-and-aft extending connecting plate or beam member 66 welded or otherwise fixed to the inner ends of the members 32-38 in parallel relationship with the member 22. The plate 66 is apertured and bolted to the corresponding plate (not shown) on the left-hand section of the main frame. Alternatively, the main frame may be formed as a single weldment with the transverse members 32-38 extending continuously through both main fore-and-aft members 22. The two-piece construction provides easier handling and shipping.

The outermost ends of the transverse members 32-38 are connected to an outer fore-and-aft extending member 70 which is generally of the same height as (but may be narrower than) the member 22. The member 70 may be apertured at locations 72, 74, 76 and 78 to receive the ends of the corresponding transverse members 32-38, and fillet welds around the locations rigidly secure the members together. In the embodiment shown in FIG. 5, both the inner and outer walls (see 70a and 70b) of the member 70 are apertured to conform to and receive the ends of the transverse members 32-38, and the end of each member projects slightly outwardly from the outer wall (see 32p of FIG. 5). Continuous fillet welds 80 between the outer wall 70b and the projection 32p, and between the inner wall 70a and the member, rigidly fix the members 32-38 to the member 70. Alternatively, only the inner wall (see 70a' of FIG. 4) is apertured, and the transverse member (T of FIG. 4) extends through the aperture and terminates within the member 70'. A continuous fillet weld is then formed around the aperture location. If the end of the member T contacts the inside of the member 70', a drain hole may be provided at 84 to assure paint can drain from within the tube T during painting operations. Apertures 90a and 90b for hinge connections are formed in the walls 70a' and 70b' near the tube T and apertures 92' in a hinge casting 94' are aligned the apertures 90a and 90b. Bolts (not shown) are inserted through the apertures 90a, 90b and 92' and tightened to secure the hinge casting 94' against the outer wall 70b'. The welded wall construction stiffens and strengthens the wall 70a' and prevents wall collapse to retain hinge bolt torque. In the double weld construction as shown in FIG. 5, additional wall strength is provided adjacent the hinge locations. Apertures 90 in the walls 70a and 70b align with apertures 92 in a hinge casting 94, which includes a hollow portion indicated generally at 96 to receive the projection 32p and fillet weld 80. Bolts (not shown) are inserted through the apertures and tightened to secure the hinge casting 94 against the wall 70b. The double weld construction stiffens and strengthens the walls 70a and 70b against collapse.

The wing frame 16 shown in FIG. 2 includes fore-and-aft member 100 apertured at locations 102, 104 and 108 to receive the transverse member 32', 34' and 38' therethrough. Fillet welds secure the members to the sidewalls of the member 100. The end of the transverse member 36' is welded to the outside wall of the member 100, and apertures at 110 are provided to mount stub frames. Hinge plates 112, 114, and 118 are welded to the ends of the members 32', 34' and 38'. If the wing frame 16 is utilized as the inner section of a five-section machine, additional hinges are mounted on the outer fore-and-aft member 70' as shown in FIG. 4. Drain holes are not required in the transverse tube (32') since the tube is totally capped by 70' and 112. Paint is allowed to move freely throughout fore-and-aft member 22' during painting operations.

As shown, the frame sections are vertically compact and lie generally within parallel planes defined by the top and bottom walls 28 and 30 (28' and 30') of the main fore-and-aft members. The tubular members 22 (FIG. 1) define a strong, continuous frame section backbone and provides excellent hitch load transfer from the transverse tubular members on the main frame 12 without bridge or sub-frame structure. A rear hitch can be attached to the aft ends (22a of FIG. 1) of the members, with the rear draft loads efficiently transferred to the front hitch through the members 22.

Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. For example, although in the preferred embodiment the fore-and-aft members are apertured, the fore-and-aft tubes could pass through apertures in laterally extending tubes.