GB2024597A - Tractor hitch - Google Patents

Abstract

A universal hitch for a tractor comprises a reversible body (31) with a mounting portion (32) intermediate its ends, a toroidal towbar eye (34) at one end, and a hitch aperture (33) adjacent the opposite end. The hitch is attachable to the drawbar of the tractor in either of two positions whereby either the towbar eye (34) or the hitch aperture (33) is positioned remote from the drawbar and the arrangement is such that the towbar eye extends further from the drawbar in one position of the body (31) than does the hitch aperture in the reverse position of the body. <IMAGE>

Description

SPECIFICATION Universal hitch for pull-type agricultural implements or vehicles The present invention relates to the mechanical connections between towing and towed agricultural vehicles and more particularly to hitches for hitching agricultural pull-type machinery and vehicles to agricultural tractors.

In Great Britain primarily two different types of hitches are widely in use, namely the so-called automatic pick-up hitch and the clevis hitch. The automatic pick-up hitch appears to have gained acceptance over the clevis hitch but it is assumed that both types of hitches will remain in use side-by-side for some long time.

With an automatic pick-up hitch, the tractor is provided with a vertical lifting hook (a so-called pick-up hook) which is usually actuated hydraulically and which is cooperable with a forged toroidal tow bar eye on the towed vehicle. With a clevis type coupling, the tractor comprises a so-called drawbar having at its free end a shackle drilled to receive a pin or bolt and adapted to cooperate with a hitch aperture provided in a drawbar on the towed vehicle.

Various components of these hitches are standardised and the dimensions and positions of the components of the automatic pick-up hitch on the one hand and the clevis hitch on the other hand differ two the extent that one half of a clevis hitch cannot readily be coupled to one half of an automatic pick-up hitch and vice versa. This is intentional and one of the considerations is that of safety.

However, it is not necessary to delve further into this matter for an understanding of the present invention. It is sufficient to state here that usually the hook of the automatic pick-up hitch is too large to cooperate with the hitch aperture of a clevis hitch.

Also the clevis of the tractor drawbar extends further rearwardly from the tractor P.T.O. (power take-off) shaft than the automatic pick-up hook.

Because the positions of the hook of the automatic pick-up hitch and the drawbar pin of the clevis hitch vary on the tractor, it is necessary to position the towed implement or vehicle correctly relative to the tractor when using a P.T.O. shaft. Thus, the tow bar eye should be positioned further forwardly on the implement or vehicle drawbar than the hitch aperture to be able to provide one and the same P.T.O.

shaft.

As a result, it is necessaryforthe manufacturers of agricultural implements and vehicles to make their products so that they can be adapted to either type of hitch under discussion. In practice one type of hitch is provided as standard on an implement or vehicle with the other type of hitch available as optional equipment and interchangeable with the standard type. This means that additional stocks must be maintained at both manufacturers and dealers and when orders are placed, careful atten tion must be given to order and supply the required type of hitch. Obviously, this may give rise to misunderstandings and mistakes, especially since much confusion appears to exist in certain instances concerning the correct names of certain hitch components.Also when a farmer replaces his tractor, it may be that he has to replace the hitches on all of his implements and vehicles to suit the newtractor.

Some implements and agricultural vehicles, and especially those which are attached and detached frequently to and from tractors when in use, are provided with a combined hitch ring and hitch aperture. In these arrangements the hitch ring or eye is provided on the drawbarforwardly of the hitch aperture. However, in practice this type of combined hitch has not proved satisfactory because the part not in use may hinder coupling to the other part.

It is an object of the present invention to overcome or to attenuate one or more of the foregoing disadvantages.

According to the invention, hitch means for a pull-type agricultural implement or vehicle comprises a reversible body with a mounting portion intermediate its ends, a toroidal towbar eye at one end, and a hitch aperture adjacent the opposite end, the mounting portion being attachable to one end of a drawbar or tongue of the implement or vehicle in either of two positions whereby either the towbar eye or the hitch aperture is positioned remote from the drawbar or tongue and the arrangement being such that in use the towbar eye extends further from the drawbar or tongue in one position of the body than does the hitch aperture in the reverse position of the body.

Thus a simple but effective universal hitch is provided and the hitch body may comprise a flat, elongate member supporting at one end the towbar eye or hitch ring and having a drilled or punched hitch aperture adjacent its other end. The drilled or punched hole has a standardised diameter which is smaller than the inner diameter of the towbar eye.

The towbar eye is, as is prescribed by the relevant standard, a forged component of prescribed dimensions and shape and it is welded or otherwise attached to the normally machined flat elongate member.

The mounting portion of the body may comprise a piece of metal secured in a position generally perpendicular to one side of the aforementioned elongate member and in the centre of the latter when seen in transverse direction. Preferably the mounting portion is secured to the drawbar or tongue of the implement or vehicle by detachable fastening means positioned closer to the hitch aperture than to the towbar eye. The fastening means may comprise bolts in use extending through aligned apertures in the mounting portion and the drawbar or tongue. If four apertures are provided they preferably are positioned on the four corners of an imaginary rectangle (which may be a square) which is thus positioned closer to the hitch aperture than to the towbar eye.The drawbar or tongue of the implement or vehicle preferably comprises at its forward end adjacent upright wall portions extend ing generally in a fore-and-aft direction of the implement or vehicle and spaced sufficently far apart to receive therebetween the mounting portion of the hitch means. The fixation apertures in the drawbar or tongue are provided in the upright wall portions in a manner two align with the apertures in the mounting portion. The offset position of the fixation apertures as between the hitch aperture and the towbar eye caters for the different hitch positions on tractors according to the type of hitch provided thereon and thus a single P.T.O. shaft can be used irrespective of the type of hitch afforded by the universal hitch of the present invention.

The hitch may be secured either on top of or below the drawbar or tongue so as to accommodate different heights of hitch components provided on tractors.

A universal hitch constructed in accordance with the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic side view, partially in section, of the hitch, Figures 2, 3 and 4 are similar views to Figure 1 with the hitch in alternative positions, Figure 5 is a schematic top view of Figure 1 taken in the direction of arrow V, and Figures 6 and 7 are schematic side views, illustrating alternative hitch means on a tractor.

With reference to the Figures 6 and 7 the alternative hitch means commonly supplied on tractors in Great Britain will first be described briefly. The tractor is generally indicated at 1 and comprises a pair of front steerable wheels 2 and a pair of rear traction wheels 3. The traction wheels 3 have their wheel axle at 4 and a PTO shaft 5 is positioned rearwardly and below the latter. Figure 6 illustrates a hitch commonly known as a clevis hitch and indicated at 6. The clevis hitch 6 comprises a drawbar 7 attached at one end to the underside of the tractor main body 8 and at a location below the PTO shaft 5.

The drawbar 7 comprises at its other end a rearwardly-facing shackle or clevis with both shanks 9 having an aperture drilled therein. The aligned apertures are adapted to receive a locking pin or bolt 10.

Figure 7 illustrates a so-called automatic pick-up hitch, generally indicated at 11 and comprising an arm 12 which is pivotally mounted at one end on the underside of the tractor main body 8 and which supports a pick-up hook 13 at its other end. The pick-up hook 13 extends, in its raised operative position, closely adjacent a locking element 14 so thatanytowbareye engaged bythe pick-up hook 13 is positively held thereon. The arm 12 may be lifted by hydraulic means which, for the sake of clarity, have not been shown, but which are well known in the art. As appears from a comparison between Figures 6 and 7, the hitch point of the clevis hitch 6 is positioned further rearwardly with respect to the tractor PTO 5 than the pick-up hitch by a distance indicated at 15.

With reference to the Figures 1 to 5, the invention will now be described in further detail. Only the forwardmost end of a drawbar or tongue 20 of the implement or vehicle is shown since the nature of the implement or vehicle is not relevant to the invention. The drawbar or tongue 20 comprises at its forward end a pair of U-shaped members 21 arranged with their central portions 22 facing each other and separated by a small distance. A support 23 is provided on the drawbar or tongue for holding the latter in a predetermined position raised above the ground when detached from the tractor. The facing portions 22 of the member 21 comprise a number, preferably four, of aligned apertures 24 for receiving fixing bolts 25. The apertures 24 are positioned at the four corners of an imaginary square or rectangle.

The universal hitch according to the invention is generally indicated at 30 and comprises an elongate flat body 31 having a mounting portion 32 welded thereto intermediate its ends. The body 31 is formed with a hitch aperture 33 adjacent one end and carries a toroidal towbar eye 34 at its other end. The towbar eye 34 is a forged component which is welded to the otherwise machined body 31. The towbar eye 34 and the hitch aperture 33 have dimensions as prescribed by relevant standards which means, inter alia, that the diameter of the hitch aperture 33 is smaller than the inner diameter of the towbar eye 34.

The body 31 is elongate and extends generally horizontally in the fore-and-aft direction of the implement or vehicle and has the mounting portion 32 welded thereto centrally of, and extending perpendicularly to, one face thereof. The mounting portion 32 comprises a number, also preferably four, apertures drilled therein in a manner to align with the apertures 24 in the portions 22 of the U-shaped members 21. The rectangle defined by the drilled apertures in the mounting portion 32 is situated closer to the hitch aperture 33 than to the towbar eye 34. The hitch 30 may be bolted to the drawbar or tongue 20 between the facing walls 22 of the members 21 either in the position as shown in Figure 1 or in the reversed position as shown in Figure 2.

Thus either the towbar eye 34 or the hitch aperture 33 may be mounted, as desired, in the operative position merely by reversing the hitch body 31.

It will be seen from a comparison of Figures 1 and 2 that because of the fore-and-aft offset of the fixation apertures in the mounting portion 32, the towbar eye 34 is in the operative position, located further from the body of the implement or vehicle body than is the hitch aperture 33 when it is in the operative position. The difference is indicated at 40 and corresponds to the spacing 15 between the hitch position of the pick-up hook 13 and the pin 10 of the clevis hitch 6. Hence the distance between the implement and the tractor P.T.O. 5 remains the same irrespective of the type of hitch employed.

Figures 3 and 4 illustrate that the hitch means 30 may be connected to the drawbar or tongue 20 in an inverted position compared with that of Figures 1 and 2. In this way the towbar eye 34 and the hitch aperture 33 are positioned somewhat lower than in Figures 1 and 2 to cater for differences in height of the hitch position on tractors.

It will be seen from the foregoing that a single componentwill adapt to either a clevis hitch ora pick-up hitch without adding or deleting items. Thus it is no longer necessary to produce an alternative type of hitch so that less components have to be produced and stored at various locations. Hence manufacture, ordering, shipping, etc. are all simplified and the risk of wrong deliveries and consequent re-orderings and complaints are eliminated. Also the owner of implements and vehicles with hitch means according to the invention will at any time be able to switch over to another type of hitch without any problems and without having to buy any additional components. Furthermore, the correct P.T.O. shaft length will always be present irrespective of the type of hitch employed. Finally, the hitch means can also be used in two height positions to cater for different types of tractors.

Claims (14)

1. Hitch means for a pull-type agricultural implement or vehicle comprising a reversible body with a mounting portion intermediate its ends, a toroidal towbar eye at one end, and a hitch aperture adjacent the opposite end, the mounting portion being attachable to one end of a drawbar or tongue of the implement or vehicle in either of two positions, whereby either the towbar eye or the hitch aperture is positioned remote from the drawbar or tongue and the arrangement being such that in use the towbar eye extends further from the drawbar or tongue in one position of the body than does the hitch aperture in the reverse position of the body.

2. Hitch means according to claim 1, wherein the hitch body comprises an elongate flat member supporting at one end the towbar eye and having the hitch aperture adjacent its other end.

3. Hitch means according to claim 1 or 2, wherein the hitch aperture has a diameter which is smaller than the inner diameter of the towbar eye.

4. Hitch means according to any of the preceding claims, wherein the towbar eye is a forged compo next which is attached to the hitch body.

5. Hitch means according to claim 4 when appended to claim 2, wherein the flat body member is a machined component and the towbar eye is welded to the body member.

6. Hitch means according to claim 2 or any claim appended thereto, wherein the mounting portion comprises a piece of metal secured generally per pendicularto one side of the elongate flat member and at the centre of the latter when seen in transverse direction.

7. Hitch means according to claim 6, wherein the mounting portion is attachable to the drawbar or tongue of the implement or vehicle by detachable fastening means positioned closer to the hitch aperture than to the towbar eye.

8. Hitch means according to claim 7, wherein the fastening means comprise bolts in use extending through aligned apertures in the mounting portion and the drawbar or tongue.

9. Hitch means according to claim 8, wherein the mounting portion and the drawbar or tongue are each provided with four apertures positioned at the corners of an imaginary rectangle.

10. Hitch means according to any of the preceding claims, wherein the drawbar or tongue of the implement or vehicle comprises at its forward end adjacent upright wall portions extending generally in fore-and-aft direction and spaced apart to receive therebetween the mounting portion of the hitch means.

11. Hitch means according to claim 12, wherein the drawbar or tongue of the implement or vehicle comprises at its forward end a pair of U-shaped members with the central portions thereof forming said wall portions.

12. Hitch means according to any of the claims 2 to 11 wherein the hitch body is in use attachable to the drawbar or tongue of the implement or the vehicle with the elongate flat member either on top of or underneath the drawbar or tongue.

13. Hitch means substantially as herein particu larly described with reference to the accompanying drawings.

14. An agricultural implement orvehicle provided with hitch means constructed in accordance with any of the preceding claims.