IE62239B1

IE62239B1 - A hitch for a tractor

Info

Publication number: IE62239B1
Application number: IE272089A
Authority: IE
Inventors: Patrick Mccormick
Original assignee: Patrick Mccormick
Priority date: 1989-08-24
Filing date: 1989-08-24
Publication date: 1995-01-11
Also published as: GB9015342D0; GB2235120A; GB2235120B; ZA897686B; IE892720A1

Abstract

The release apparatus for a pick-up hitch of an agricultural tractor comprises at least one hydraulic cylinder 150 operable by the hydraulic system of the tractor to move the support fingers 140, 141 of the pick-up hitch and thereby allowing the pick-up hitch to be released.

Description

The present invention relates to hitches for tractors, and more particularly to pick-up hitches for agricultural tractors.

In a pick-up hitch, the hook of the hitch is released and lowered about a pivot point until the point of the hook is below the towing eye of the trailer or other device to which the tractor is being hitched. The tractor is then reversed until the point of the hook is underneath the towing eye. Raising of the hook causes it to engage with the eye and this supports the tractor or other device. To uncouple the trailer or device, the hitch is first raised by the hydraulic lift of the tractor and the supporting fingers of the hitch are pulled to an inoperative position, to enable the hitch to be lowered, by the driver of the trailer from the tractor cab, using a mechanical cable system or a lever and linkage system.

Both the mechanical cable system and the lever and linkage system suffer from numerous disadvantages. Both require the use of physical effort from the driver, some systems are mounted in regions of the cab which are not very accessible. Also, both a cable system and a lever and linkage system are susceptible to being clogged and blocked by dirt and to rusting.

The object of the invention is to alleviate the above disadvantages . - 2 The present invention provides release apparatus for a pick-up hitch of an agricultural tractor, comprising at • least one hydraulic or pneumatic cylinder operable by the hydraulic or pneumatic system of the tractor to move the or * each support finger (as herein defined) of the pick-up hitch, thereby enabling the pick-up hitch to be lowered, with one end of the hydraulic or pneumatic cylinder being connected to a first support finger, the cylinder being operable to move the first support finger to an inoperative position, the first support finger being connected to the second support finger by a rotatable shaft, whereby « movement of the first support finger causes corresponding movement of the second support finger, and with biasing means being provided to return the or each support finger to the operable position on deenergization of the hydraulic or pneumatic cylinder.

Advantageously, at least one safety feature element is provided so as to prevent movement of the or each support finger by the hydraulic or pneumatic cylinder.

Conveniently, the power transmission means between the support fingers is a rotatable shaft and one of the safety feature elements comprises a pin engageable with a hole in the shaft and a hole in a fixed member.

* Preferably, a further safety feature comprises means for disconnecting the supply of hydraulic fluid or air to the cylinder when it is not required.

The invention also provides a pick-up hitch for an agricultural tractor including said release apparatus of the invention.

The invention will hereinafter be more particularly described with reference to the accompanying drawings, which show by way of example only, three embodiments of a pick-up hitch according to the invention. In the drawings: Figure 1 is a perspective view of a first embodiment of a pick-up hitch suitable for use on a Zetor Crystal (Trade Mark) or Ursus (Trade Mark) agricultural tractor; Figure 2 is a perspective view of a second embodiment of a pick-up hitch suitable for use on a Deutz-Fahr (Trade Mark) agricultural tractor; and Figure 3 is a perspective view of a third embodiment of a pick-up hitch suitable for use on a Mercedes (Trade Mark) agricultural tractor.

In the three embodiments shown in the drawings, the elements are identified by three digit numerals, with the first digit identifying the first, second or third embodiment respectively and the second and third digits being used to indicate like parts in each embodiment.

Referring to the drawings, and initially to Figure 1, the pick-up hitch 100, comprises a frame 110 which is secured to the underneath of the tractor (not shown) and a support box 120, one end of which is pivoted to the frame 110 by pivot pin 125. A towing hook 130 is secured to the other end of the box. At either side of the hook 130 is a support arm 135 which is engagable with a support finger 140 and 141. A rotatable shaft 145 connects the two support fingers 140 and 141.

A hydraulic cylinder 150 is connected via a crank 152 to the upper end of the support finger 140. Movement of ram 151 from the cylinder 150 moves the support fingers in an anti-clockwise direction, provided the lift arms 160 have first been raised to lift the support arms 135. A spring 170 returns the support fingers 140 and 141 to their operative position. Stops 180 are provided on the shaft 145 to prevent excess travel of the ram 151 from the cylinder.

Also provided in the frame 110 of the pick-up hitch is a plate 190 having a viewing hole 195 through which the driver of the tractor can see the hook 130 when it is in its lowered position.

The end (not shown) of the hydraulic hose 197 is provided with a connector which can be uncoupled from the hydraulic connecting valves provided at the rear of the tractor, so as to prevent accidental use of the cylinder 150.

The second embodiment of pick-up hitch 200, shown in Figure 2, is similar to the first embodiment, except that the arrangement of the support fingers and the hydraulic cylinder 250 is different.

Also visible in Figure 2 is a safety pin 246 which engages with a hole 247 in the shaft 245, and connector 298 which may be connected and disconnected with the hydraulic supply valves at the back of the tractor, not shown.

Figure 3 shows the third embodiment of pick-up hitch 300 which illustrates a third arrangement.

Claims

CLAIMS :

1 . Release apparatus for the pick-up hitch of an agricultural tractor, comprising at least one hydraulic or pneumatic cylinder operable by the hydraulic or pneumatic 5 system of the tractor to move the or each support finger (as herein defined) of the pick-up hitch, thereby enabling the pick-up hitch to be lowered, with one end of the hydraulic or pneumatic cylinder being connected to a first support finger, the cylinder being operable to move the 10 first support finger to an inoperative position, the first support finger being connected to the second support finger by a rotatable shaft, whereby movement of the first support finger causes corresponding movement of the second support finger, and with biasing means being provided to return the 15 or each support finger to the operable position on deenergization of the hydraulic or pneumatic cylinder.

2. Release apparatus as claimed in Claim 1 in which at least one safety means is provided so as to prevent 20 movement of the or each support finger by the hydraulic or pneumatic cylinder.

3. Release apparatus as claimed in Claim 2 in which one of the safety means comprises a pin engagable with a hole in the shaft and a hole in a fixed member of the apparatus.

4. Release apparatus as claimed in either Claim 2 or 3 in which one of the safety means comprises means for 5. Disconnecting the supply of hydraulic fluid or air to the cylinder when it is not required.

5. A pick-up hitch for an agricultural tractor including a release apparatus as claimed in any one of the preceding 1 0 claims.

6. Release apparatus substantially in accordance with any of the embodiments herein described with reference to and as shown in the accompanying drawings.

7. A pick-up hitch for an agricultural tractor substantially in accordance with any of the embodiments herein described with reference to and as shown in the accompanying drawings.