GB2201072A

GB2201072A - A towing rig

Info

Publication number: GB2201072A
Application number: GB08701162A
Authority: GB
Inventors: Dennis Grocock
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-01-20
Filing date: 1987-01-20
Publication date: 1988-08-24
Also published as: GB8701162D0

Abstract

A towing rig for towing an agricultural implement behind a combination of tractor 9 and agricultural implement 11 comprises a tow chassis 1, wheels 6 for supporting the tow chassis 1 over the ground and linkage means 2 at the rear of the tow chassis 1 adapted, in use, to secure the agricultural implement to the towing rig. The towing rig may be coupled directly to the tractor 9, between the tractor 9 and the agricultural implement 11, and/or to the agricultural implement 11. The coupling may take the form of a ball and socket arrangement 8, or a swivel joint. <IMAGE>

Description

DESCRIPTION A TOWING RIG The present invention relates two a towing rig-for towing agricultural implements along behind a tractor or similar vehicle, and more particularly to a towing rig which allows a second agricultural implement to be towed along behind a tractor or similar vehicle already towing a first agricultural implement.

In arable farming the ground must usually be harrowed before a crop can be sown. Conveniently, these two operations of harrowing and drilling the ground are carried out simultaneously by a power harrow and a power seed drill, the drill following the harrow over the ground. Sometimes it may also be necessary to plough the land before it is harrowed and drilled.

Conveniently, it is known to use separate tractors for each implement used on-the land. This technique allows each implement to be separately engaged and disengaged with the ground which is particularly important where the implements are to be transported between operating sites. Moreover, it also results in a minimal load being placed on the rear axle of each tractor and thus relatively small, low power tractors can be used which do not overly compact the ground as they pass over it. However, this technique is not completely satisfactory, not least because the wheels of the second and third tractors tend to compact the soil over which the plough and harrow have passed before the drill reaches it.Moreover, because this arrangement requires the use of two separate tractors it also requires two operators, one for each tractor, which is wasteful of farming resources.

In order to overcome the problems of the technique outlined immediately above it is known to carry the power seed drill on the back of the power harrow, "piggyback" fashion and tow the combined unit with a single tractor. This obviates the problem of soil compaction in front of the power seed drill which occurs when it is towed separately behind the power harrow, but it does place a considerable load on the rear axle of the tractor when both implements are lifted off the ground simultaneously. This means that a very much more powerful and hence heavier tractor must be used to tow the combined implements -than would be necessary if the two -implements were to be towed separately. These large tractors cause severe soil compaction as they pass over it, thus increasing the amount of harrowing required.Moreover, transporting the combined units between sites can be difficult because of their combined weight and size. Furthermore, it is inefficient to use such large tractors for operations of relatively low power and/or draft requirements, simply because the combined weights of the two implements rules out the use of a smaller tractor.

It is an object of the present invention to provide a towing rig whereby a second agricultural implement can be towed along behind a tractor or similar vehicle towing a first agricultural implement without placing the full weight of the two implements on the rear axle of the tractor when the two are lifted off the ground simultaneously.

In order for agriculture to become more efficient the use of agricultural impliments of relatively large width is often preferred. However, this may cause problems where small openings into and out of fields have to be negotiated. Moreover, wide implements cannot be transported on the public highway.

It is a further object of the present invention to provide a towing rig whereby a second agricultural implement can be towed behind a tractor or similar vehicle towing a first agricultural implement which facilitates independent operation of the two implements and handling and transportation of the two implements between operating sites.

According to the present invention there is provi-ded a towing rig whereby a second agricultural implement can be towed along behind a tractor or similar vehicle capable in use of towing a first agricultural implement, comprising a tow chassis, wheels for supporting the tow chassis over the ground and linkage means at the rear ofthe tow chassis adapted in use to secure said second agricultural implement thereto.

As is conventional, the first implement is secured to the rear of the tractor by some form of coupling means. This usually takes the form of a three-point linkage, but may also comprise a ball and socket arrangement.

Preferably, the tow chassis comprises coupling means at its forward end whereby it may be coupled to the rear of the tractor or to coupling means connecting the first implement to the- tractor. Conveniently, said coupling means comprises a ball and socket arrangement.

Alternatively, it may comprise a swivel joint.

Preferably, the towing rig comprises a drive shaft, adapted in use to be coupled to a drive output provided at the rear of the tractor. This drive output can be taken to the wheels of the towing rig through a differential drive arrangement. It can also be used to drive the second implement carried at the rear of the towing rig by the three point linkage. Alternatively, the second implement may be hydraulically operated and take its hydraulic drive from the tractor hydraulics.

It will be readily understood that three point lingages to which the first and second implements are secured enable each implement to be raised from or lowered into engagement with the ground. Conveniently, a hydraulic ram is used to power each three point linkage with power being taken from the tractor hydrau-lics. Advantageously, each three point linkage is capable of being operated independently of the other.

Preferably, the tow chassis also comprises an extendable arm member which is pivotably secured towards the forward end of the tow chassis and is movable between stowed position in which it lies alongside the tow chassis and an operative position in which it extends forward of and downward from the end of the tow chassis. During transport and handling the towing rig is coupled direct to the tractor via the extendable arm member.

Preferably, the towing chassis is comprised of a parallel linkage frame, each side of which is pivotally secured to its neighbour to allow maximum flexibility of movement in a vertical plane between the two implements at each end of it.

In use the towing rig is coupled to the rear of a tractor carrying a first farming implement, such as a power harrow, either directly or via said coupling means.

It will be readily apparent that with the towing rig of the present invention the weight of the first implement is supported by the back axle of the tractor, as would be the case when it is towing a single implement.

However, the weight of the second implement is supported by the axle of the towing rig and does not bear down on the back axle of the tractor at all. Indeed, through the lever provided by the tow bar about the wheels of the towing rig the weight of the second implement tends to counterbalance the weight of the first implement.

Thus, the tractor is not required to support the combined weights of the two implements on its back axle when the two are lifted together, but simply to tow it.

In a preferred embodiment of the present invention the towing rig is provided with engagement means whereby it can be engaged with one end of the first implement carried by the tractor, and the opposite end of the first implement is modified to comprise a towing member which can be coupled to the towing member of the tractor.

By rotating the first implement through 90 degrees so that the end thereof carrying the towing member lies forward and the other end lies under the tow bar and then hitching the end of the first implement to the tow bar an integral unit is formed. This unit can ten be coupled to the tractor by the towing member carried by the first implement. In this embodiment of the present invention farming implements of relatively large width can be towed behind a tractor through narrow openings into fields etc. and without causing an obstruction on the public highway.

Am embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows a side view of a towing rig in accordance with the present invention, coupled to the rear of a tractor in a power harrow; Fig. 2 shows a side view of the extendable arm carried by the towing rig in its operative position; Fig. 3 shows a plan view of the towing rig of Fig. 1 coupled to the rear of a tractor, partially shown, through a power harrow; Fig. 4 shows substantially the same view as Fig. 3 except that the tractor and power harrow have been steered through 90 degrees with respect to the towing rig; Fig. 5 shows a side view of the power harrow and towing rig of Fig. 4 with the tractor discoupled from the power harrow;; Fig. 6 shows an enlarged detailed view of the securing means used to secure the end of the power harrow to the tow chassis, and Fig. 7 shows a side view of an alternative towing rig in accordance with the present invention coupled to the three point linkage coupling a first implement to the rear of a tractor.

Referring now to Fig. 1 of the accompanying drawings there is shown a towing rig according to the present invention comprising a tow chassis 1 having at one end a three point linkage 2 whereby an agricultural implement (not shown), such as a power seed drill, is secured to the towing rig. The three point linkage 2 is pivotable in a vertical plane about its connection to the towing chassis 1 and is driven about its pivot point by-means of an hydraulically operated ram 4.

The ram 4 enables the the implement to be raised from or lowered into engagement with the ground by raising or lowering the lowermost lever 5 of the three point linkage 2. The end of the two chassis carrying the support frame 2 is supported on the ground on a pair of wheels 6.

At the opposite end of the tow chassis 1 from the three point linkage 2 is provided a towing ball 7 (see Fig. 2) which is received in a complimentary towing socket 8 carried at the rear of a further agricultural implement 11. The implement 11 is coupled to the rear of a tractor 12 by means of a further three point linkage 10 essentially the same as the one at the rear of the towing rig. The three point linkage 10 serves to raise or lower the implement 11, such as a power harrow, out of or into engagement with the ground in the same manner as implement 3 by means of an hydraulically operated ram (not shown). In order to allow the tow chassis 1 to be connected directly to the rear of the tractor 9 an extendable arm member 14 is pivotably connected towards the forward end of the tow chassis 1.

In Fig. 1 this extendable arm member 14 is shown in its stowed position, resting along the top of the tow chassis 1. However, as shown in Fig. 2 it can be pivoted forward of the tow chassis to facilitate coupling via foot 13 to a towing peg at the rear of the tractor 9.

Although not shown-in any of the drawings, the towing rig may be provided with a drive shaft which can be connected to the tractor drive output. Most tractors provide such a drive output at the rear and this can be used to drive the wheels 6 of the towing rig and/or to operate the implement 3 if such a drive is appropriate. Usually the implement will require an hydraulic drive of some sort and in this case the hydraulic drive can be taken from the tractor~hydraulics operating the three point linkage rams.

In use the towing rig is coupled to the rear of a tractor carrying the power harrow implement 11 by means of the complimentary ball and socket members 7, 8.

The power seed drill implement (not shown) is also connected to the rear of the towing rig by means of the three point linkage 2. It will be readily apparent that with the towing rig of the present invention the weight of the power harrow implement 11 is supported by the back axle of the tractor 9, as would be the case when it is towing a single implement. However, the weight of the power seed drill implement is supported by the wheels 6 and axle (not shown) of the towing rig and when lifted does not bear down on the back axle of the tractor 9 at all. Indeed, through the lever provided by the tow bar 1 about the wheels 6 of the towing rig the weight of the power seed drill implement tends to counterbalance the weight of the power harrow implement 11.Thus, the tractor 9 is not required to support the combined weights of the two implements 2 and 11 on its back axle, when the two are lifted together but simply to tow it.

Referring now to Figs 3, 4 and 5 of the accompanying drawings there are shown three views of the towing rig of the present invention without an implement secured to the rear of the towing rig, although in practice one would usually be present, and a modified power harrow 11; which in use is carried by the tractor 9. These drawings illustrate how the towing rig of the present invention may be used in combination with a modified agricultural implement 11 to facilitate transportation of the implement to and from an operating site.

In Fig. 3 the tradtor 9 is towing the implement 11 and the towing rig 15 behind it as it would in use.

Once use of the implement 11 is concluded the implement 11 is turned through 90 degrees by the tractor 9 to bring one end of the implement 11 under the towing rig 15 and the opposite end forward of the towing rig 15, as is shown in-Fig. 4. Referring now to Fig. 5 which shows a side view of the same arrangement as Fig. 4 with the tractor decoupled from the implement 11 as it is possible to see that the implement 11 has been modified at th-e end under the towing bar 1 to comprise a securing member 16 which facilitates its attachment thereto, and the opposite end of the implement 11 has been modified to provide a towing member 17 which can be coupled to the towing member at the rear of the tractor once it has been brought round into the appropriate position.Fig. 6 shows the securing member 16 in greater detail and illustrates how it is formed of a U-shaped channel which is secured onto the tow chassis 1 by means of a locking pin 18 which passes through holes in its side limbs. A stand 19 is provided at the towed end of the implement 11 to support the end whilst it is coupled at the rear of tractor 9. For convenience the height of the stand is adjustable.

In this embodiment of the present invention implements of relatively large width can be towed behind a tractor through narrow openings into fields, etc. and without causing an obstruction on the public highway.

Referring now to Fig. 7 of the accompanying drawings there is shown an alternative towing rig in accordance with the present invention. This towing rig is substantially the same as in the previous embodiment However, it differs inasmuch as the tow chassis comprises a four sided parallel linkage frame 23. The parallel linkage frame23 maintains the first and second implements at the same angle (in a fore and aft direction) to each other although either or both may be raised from or lowered into engagement with the ground. This arrangement also incorporates pivots 24 which allow the towing r.ig to pivot in a horizontal plane relative to the tractor and first implement as it follows along behind.

A further pivot point 25 allows the towing rig to "twist" about a horizontal axis relative to the tractor and first implement.

It will be readily apparent that this embodiment of the present invention allows complete freedom of movement for the towing rig as it follows the tractor and first implement over the ground.

Claims

1. A towing rig for towing an agricultural implement behind a combination of tractor and agricultural implement, comprising a tow chassis, wheels for supporting the tow chassis over the ground and linkage means at the rear of the tow chassis adapted, in use, to secure the agricultural implement to the towing rig.

2. A towing rig according to Claim 2, wherein the tow chassis comprises an extendable arm member which is pivotably connected to the said tow chassis and is moveable between- a stowed position in which it lies alongside the tow chassis and an operative position in which it extends forward of and downward from the tow chassis to secure the towing rig to said combination of tractor and agricultural vehicle.

3. A towing rig according to Claim 1 or 2, comprising coupling means adapted, in use, to connect the towing rig to the said combination of tractor and agricultural vehicle.

a. A towing rig according to Claim 3, wherein the coupling means comprises a ball or a socket of a ball and socket ..

arrangement.

5. A towing rig according to Claim 3, wherein the coupling means comprises a swivel Joint.

6. A towing rig according to any preceeding Claim, comprising a drive shaft adapted, in use, to coupled to a drive output of the said tractor.

7. A towing rig according to any preceding Claim, wherein the said linkage means comprises a three point linkage.

8. A towing rig according to Claim 7, wherein the said three point linkage is operated by means of an hydraullic ram, power for the hydraullic ram being obtained from the said tractor.

9. A towing rig according to any preceeding Claim. wherein the towing chassis defines a parallel linkage frame, each side of which is pivotally secured to its immediate neighbour, thereby allowing the said agricultural implement to move in a vertical plane.

10. A comPination of a tractor, a first agricultural implement coupled immediately behind the said tractor, a towing rig according to any preceeding Claim coupled to the rear of said tractor and a second agricultural implement linked to said towing rig.

11. A combination according to Claim 10, wherein the towing rig comprises engagement means whereby it can be engaged with one end of the said first agricultural implement, and the opposite end of the said first agricultural implement comprises a tow coupling whereby it can be coupled behind the said tractor.

12. A towing rig for towing an agricultural implement behind a combination of tractor and agricultural implement substantially as hereinbefore described with reference to the accompanying drawings.

13. A combination of a tractor, a first agricultural implement coupled immediately behind the said tractor, a towing rig coupled to the rear of said tractor and a second agricultural implement linked to said towing rig substantially as hereinbefore described with reference to Figs 3 to 6 of the accompanying drawings.