DESCRIPTION

This invention relates to a hitch system for connecting a trailer or implement to a vehicle. The term 'implement' is used to describe any form of machinery which may be attached to a vehicle and includes, for example, buckets, loaders, diggers, spreaders, bale shredders, flail cutters etc.

A typical hitch system for connecting an implement to a tractor is illustrated with reference to Figures 1, 2 and 3. A tractor 10 comprises two outwardly extending spaced apart bars 12, 14 and close to a free end of each bar there is provided a swivel eye 15 defining an aperture through the bar. Attached to an implement 16 are spaced apart arms 18, 20 each provided with parallel flanges 22, 24 at a free end thereof. In order to hitch the implement to the tractor, the arms 18, 20 are positioned such that their flanges 22, 24 overlap their respective bars 12, 14 and such that an aperture 26 through flanges 23, 24, is aligned with the swivel eye of the bar. A threaded bolt 28 is passed through the flanges and swivel eye and secured by nut 30 such that the bar is held between the flanges and hence the connection between the implement

and tractor is made.

Another known hitch system comprises two arms extending outwardly from the implement with each arm having at the free end thereof an inwardly extending pin and with the tractor being provided with the bars described above. In order to hitch the implement to the tractor it is necessary to carefully align the swivel eye of each bar of the tractor onto the pin of the respective arm of the implement. The problem associated with the above-mentioned hitch systems and other similar systems is that it is necessary to accurately align the bars from the tractor with arms extending from the implement in order to form the connection. Consequently the task of hitching an implement to a vehicle is time consuming and sometimes requires a degree of physical effort if the implement needs to be manoeuvred in order to correctly align the flanges with respect to the swivel eye of each bar.

An aim of the present invention is to provide an improved hitch system.

In accordance with the present invention there is provided a hitch system for connecting a trailer or implement to a vehicle comprising a first member having a receiving position and a captive position and a second member locatable in said receiving position and movable from said receiving position to said captive position in

order to form a connection between said members.

In a preferred embodiment of the invention, the hitch system further comprises means for guiding the second member into said receiving position. The captive position may lie in the same vertical plane as the receiving position and may lie, substantially, vertically above said receiving position.

The receiving position and captive position may be formed in an integral member. The first member may comprise a body having a first part defining the receiving position and a second part defining the captive position. Preferably, said first part incorporates said guide means. The guide means may take the form of wings extending outwardly from said receiving position. The second part may comprise a hollow cylindrical body which may have a substantially vertical slot formed in a side wall thereof. The second part may further comprise a socket and said socket is preferably located at the top of the cylindrical body.

The first member may be pivotally mounted and may pivot about a vertical axis.

The second member may comprise a longitudinal body and may have a head formed at the free end thereof. The head may be pivotally mounted to the body. It is preferred that the head pivots about a vertical axis.

In a preferred embodiment of the invention, the body is provided with an aperture close to the free end thereof and may receive a swivel eye. The head may be formed in two halves. Each half may be located on either side of the body and means may be provided in order to secure the halves together through said swivel eye. Said securing means may take the form of a threaded bolt and nut.

It is preferred that said first member is connected to the trailer or implement and that said second member is connected to the vehicle.

In an embodiment of the invention, the hitch between the trailer/implement and vehicle is formed by reversing the vehicle such that the head of the second member comes into contact with the guide means, further reversing of the vehicle results in the head being guided to the receiving position. With the head in such a position, the body and head are then raised into the captive position such that the head is retained within the cylindrical body of the second member with the upper part of head located in the socket and the body extending through the slot. In a preferred embodiment of the invention, the second member further comprises means for securely retaining the head within the cylindrical body. Said means may be provided by a pin located through the cylindrical body.

It is envisaged that there will be provided at least two pairs of a first and second member to connect the tractor/implement to the vehicle.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, wherein:-

Figures 1, 2 and 3 illustrate a prior art hitch system;

Figure 4 illustrates a receiving and a captive member and a locating member according to an embodiment of the present invention;

Figure 5 is a schematic illustration of and embodiment of the present invention;

Figure 6 is a side perspective view of a coupling bar;

Figure 7 is a side view of one half of a swivel ball;

Figure 8 is an end view of the swivel ball illustrated in Figure 7 and taken in the direction of arrow A;

Figure 9 is a sectional view taken along X-X of the swivel ball illustrated in Figures 7 and 8;

Figure 10 is a top sectional view of the coupling bar with the two halves of the swivel ball connected together;

Figure 11 is a front view of the receiving and

captive member;

Figure 12 is a sectional view taken along Y-Y of the member illustrated in Figure 11 and with the swivel ball and coupling arm in position X; Figure 13 is the sectional view as shown in figure 11 illustrating the swivel ball and coupling arm in position Y;

Figure 14 is a perspective view of a further embodiment of the present invention; Figure 15 is a front view of the embodiment shown in figure 14;

Figure 16 is a perspective view of a receiving and captive member according to another embodiment of the present invention; and Figure 17 is a perspective view of an alternative coupling arm.

With reference to Figures 4 and 5 in the first instance, a hitch system comprises a locating member 40 and a receiving and captive member 42. In the first instance, the adaptation of a conventional coupling bar of a tractor to a locating member in accordance with an embodiment of the invention will be described with reference to Figures 5 to 10.

A tractor 44 comprises two controllable coupling bars 46, 48. Bar 46 comprises first and second sides

49, 50, end face 51, top side 52 and bottom side 53. An

aperture 54 through the bar is located near the end face 51, and a swivel eye 56 is received in said aperture and provides, in effect, a pivotable aperture. A swivel ball 60 comprises two halves 62, 64 and first half 62 is illustrated in greater detail with reference to Figures 7 to 9. Ball half 62 comprises curved outer surface 66 and a flat inner face 69. A square recess 70 is formed in face 68 and is defined by base 72, end wall 74 and side walls 76, 78. An aperture 80 extends from base 72 through the body of the ball half 62. The second ball half 64 is similarly provided with a square recess and an aperture through its body.

In order to adapt the coupling bar, halves 62, 64 are positioned one either side of the bar such that apertures 80 coincide with swivel eye 56 and a part of the bar is located within both recesses ie., first side 49 abuts base 72 of ball half 62 and second side 50 abuts base 72 of ball half 64. With the halves positioned in such a manner, a screw is passed through aperture 80 of ball half 62, through swivel eye 52 and through the aperture through ball half 64. The screw engages with threads provided in the apertures such that the two halves are secured together but are not clamped to respective sides of the bar. In this position, the ball is free to pivot with the swivel eye.

An implement 82 comprises two outwardly extending

arms 84,86 and securely attached to the end of each arm is a receiving and captive member 42.

The member 42 is illustrated in greater detail with reference to Figure 11 and comprises a body 88 having an upper and lower section 90, 92. The upper section 90 is in the form of a hollow cylinder defining an inner space 91 and a socket 93 is formed at the top of the cylinder. A vertical slot 94 is defined in the wall of the cylinder. Located near the bottom of the upper section there is provided two diametrically opposing apertures 95 in the cylindrical body. A pin 96 is located through the apertures and hence passes across the inner space 91. The lower section comprises outwardly extending wings 98 and 100. The hitching of the implement will now be described with reference, in particular, to Figures 5, 12 and 13. The tractor 44 is reversed such that the swivel balls located on the end of coupling bars 46, 48 come into contact with the wings 98, 100 of respective receiving and captive members 42. Further reversing of the tractor results in the swivel balls being guided by the wings into their receiving position ^' X' - see Figure 12. It will be seen that in this position, the swivel ball is vertically below the cylindrical body and that the coupling bar lies directly below slot 94.

The coupling bars are then raised, under control

from the tractor, such that each swivel ball enters the inner space 91 of the hollow cylindrical body directly above it, an upper part of the ball is received in the socket 93 and the coupling bar slides into slot 94. The swivel ball is held in its captive position Y (see Figure 13) by the walls of the cylinder and socket 93. The ball is greater in diameter than the width of the slot and hence it is not possible for the ball to be removed by movement of the coupling arm in the horizontal direction.

In order to prevent downward movement of the swivel ball from the captive position Y ' , the pin 96 is inserted through apertures 95.

Since the swivel ball is free to pivot with the swivel eye of the coupling bar the coupling bar is able to pivot, to a certain degree dictated by the width of the slot, about a vertical axis. The coupling bar is also able to pivot about the swivel ball through a horizontal axis. The provision of the wings 98, 100 enables the hitching of the implement to the tractor to proceed without the need for accurate alignment of the coupling members.

In an alternative embodiment (not illustrated), the receiving and captive member 42 is pivotally mounted onto the end of each arm so as to enable the respective

coupling arm held in said captive position to pivot to a greater extent than in the above described embodiment.

A further embodiment of the invention will now be described with reference to figures 14 and 15. A receiving and captive member is shown and indicated by numeral 110. Said member has a back plate 112 with a number of holes 114 formed therein for ease of connection to an arm of an implement. The body of the member is substantially a hollow cylinder, at least in its lower part, and has a vertical aperture 116 formed in a side wall thereof which extends from a position close to the bottom end 118 of the body to the top of the body. Towards the top of the body the wall of the body flares outwardly such that the diameter of the open top 120 is greater than the diameter of the body at its lower end. Aperture 116 is bounded by two side walls 122 and 124 and said walls are substantially parallel in the lower part of the body but diverge outwardly in the upper part. The body is provided with rounded bottom 128 which defines a captive position. Formed in the wall of the body is an aperture 130.

A coupling bar which is connected to a vehicle is shown and indicated by numeral 131, at a free end of said bar a ball 132 is formed. The ball 132 is shown, in dotted outline, in figure 16 in the receiving

position X and the captive position is indicated by letter Y.

In use and in order to connect an implement to a vehicle, the coupling bar is lifted and placed above the body as indicated by arrow z. The ball is lowered into receiving position X and then subsequently lowered into the captive position Y. As the ball is lowered it becomes retained by the wall of the body since aperture 116 decreases in size and hence the ball reaches a position wherein the aperture is too small to allow passage of the ball although, of course, allowing passage of bar 131. With the ball in the captive position, a pin (not shown) is inserted into the body through aperture 130 thereby preventing the ball from moving upwards and being released from the body.

In the above manner a secure connection can be made between an implement and a vehicle.

Turning to figures 16 and 17 an alterative receiving and captive member and a coupling bar are illustrated. The member comprises an upper and lower part 140, 142. The lower part 142 defines a receiving position X and extending outwardly are wings 144 and 146. The upper part 140 defines a captive position Y and comprises a body 148. Extending from said body 148 are limbs 150, 152 which define between them a vertical slot 154. A curved arm 156 extends, as shown, from said

body and through the vertical slot 154.

A coupling bar is indicated by numeral 160 and comprises an arm 162 having an aperture 164 formed therein at an end thereof and a segment of a cylinder 166. In order to secure the segment 166 to the arm, a plate 168 having a central aperture 170 is welded to each side of the segment such that with the segment positioned on the arm as shown, the apertures 170 and aperture 164 of the arm are aligned. The segment 166 can then be secured to the arm by way of a bolt and nut.

A connection is formed between a vehicle and a trailer fitted with the coupling bar and receiving and captive member in a similar manner as described above with reference to figures 5, 12 and 13. It should be noted that in the captive position the outer surface 172 of the segment abuts the curved arm 156 of the body.