GB2078079A

GB2078079A - Coupling device

Info

Publication number: GB2078079A
Application number: GB8015840A
Authority: GB
Original assignee: WHITE EILEEN ALICE
Current assignee: WHITE EILEEN ALICE
Priority date: 1980-05-13
Filing date: 1980-05-13
Publication date: 1982-01-06
Also published as: GB2078079B

Abstract

The present invention concerns an improved hitch for coupling implements to a towing vehicle. A hitch for coupling implements to a towing vehicle comprises a plug member 12 which is connectible with a socket member 14, and catch means 32 for locking the plug and socket members when interconnected, one of the members having attachment means for connection with the towing vehicle and the other member being secured to the implement for connection with the towing vehicle, the socket member having a tapered collar for guiding the plug member into engagement therewith. <IMAGE>

Description

SPECIFICATION Coupling device The present invention relates to a coupling device and in particulartocoupling an implement to atrac- tor.

Tractors are provided with attachment links in the form of a three point mounting by means of which an agricultural implement may be coupled to the tractor. The mounting attachment consists of a pair of lower lifting links and a top link which are pivotally attached to the tractor. To couple known implements to tractors these three links have to be aligned with corresponding pickup points on the agricultural implement. The implement may be heavy and dif ficultto manoeuvre by hand and aligning the tractor with the implement may require the driver to manoeuvre the tractor accurately into the desired position. This may involve climbing in and out of the tractor cab several times to line up the tractor and implement. It may even be necessary to manhandle the implement to achieve the final coupling.

It is an object of the present invention to provide a hitch for coupling a towing vehicle, e.g. a tractor, to an implement which enables coupling to be performed without the driver having to leave the cab or having to manhandle the implement to effect the coupling.

According to the present invention there is provided a hitch for coupling implements to a towing vehicle comprising a plug member which is connectible with a socket member, and catch means for locking the plug and socket members when interconnected, one of the members having attachment means for connection with the towing vehicle and the other member being secured to the implement for connection with the towing vehicle, the socket member having a tapered collar for guiding the plug member into engagement therewith.

Preferably the plug member is provided with the attachment means, which comprise a pair of bottom pins disposed laterally of and on either side of the plug member and a top attachment link pin disposed above and between the pair of bottom pins. The attachment means connects with the three point mounting tractor attachment links.

The plug member may comprise an A frame which carries the respective attachment pins and from which projects a tapered spigot which narrows in a direction away from the A frame. The plug member is preferably fabricated from sheet steel and the tapered spigot is hollow having a rectangular crosssection. Conveniently the socket member is secured to the implement to be towed and has a complementary shaped tapered rectangular socket into which the spigot is received. Atapered collar is disposed around the mouth of the socket and extends in a direction away from the socket.

Preferably the catch means comprises a pair of arms pivotally secured to the plug member and having a respective catch which projects through a respective opening in the plug member and is received in a respective opening in the socket member. Actuating means are provided for displacing the arms to lock or unlock the plug and socket members.

Preferably the plug member has drive means comprising a splined shaft which engages with the power take-off shaft of the tractor and which carries a preferably square shaped drive coupling within which is received a tapered drive peg carried by the socket member and coupled with the implement drive shaft.

Conveniently, the hitch may incorporate a coupling by means of which the hydraulic/air lines from the tractor to the implement may be interconnected when the mechanical coupling of the tractor to the trailer is made.

The present invention will now be described further by way of example only with reference to the accompanying drawings in which: Fig. 1 illustrates that part of the hitch which is secured to a tractor; Fig. 2 is a perspective view of the plug and socket members of one embodiment of a hitch in accordance with the invention; Fig. 3a is a sectional view of the hitch catch means taken along the line I-I of Fig. 3b; Fig. 3b is a sectional view of the hitch of Fig. 3a taken along the line ll-ll; Fig. 4 is a diagrammatic side view of a second embodiment of the hitch, with the socket member cut away for clarity; and Fig. 5 illustrates one embodiment of a power coupling arrangement for the hitch.

Referring to the drawings of Figs. 1 and 2 there is shown a hitch for coupling implements to a tractor.

A tractor only partially indicated at 2 in Fig. 1 is provided with an attachment linkage 4, having a three point mounting, a top link 6 and a pair of lower lifting links 8 (only one of which is illustrated). An hydraulic powered lever arrangement 10 facilitates lifting. This type of three point mounting is a standard fitting on ,agricultural tractors.

The hitch comprises a plug member 12 and a socket member 14 which are connectible. The plug member 12 has an 'A' frame 16 whose apex is formed with bores 18 which receive a top attachment link pin 20 of the top link arm and each ieg 22 carries an attachment pin 24 for receiving the pair of lower attachment links 8 of the three point mounting.

The plug member carries a spigot 26 which is hollow, is rectangular in cross-section and has four walls which taper towards one another in a direction away from the A frame. The plug member is preferably constructed as a welded steel fabrication.

The socket member 14 has an opening 28 which is complementary in shape with the spigot 26 and is secured to the implement to be coupled to the tractor. A tapered collar 30 is provided which surrounds the mouth of the opening and which acts as a guide during interconnection of the plug and socket mem The drawings originally filed was/were informal and the print here reproduced is taken from a later filed formal copy.

bers.

Figs. 3a and 3b illustrate catch means 32 which are operative to lock the plug and socket members when interconnected. The catch means comprises a pair of arms 34 which carry a respective projection 36 and which are pivotally mounted to the plug member by means of spindles 38. The projections 36 when the arms are in the locked position pass through respective openings 40 in the plug member and openings 42 in the socket member. The arms 34 are actuated in the illustrated embodiment by a respective hydraulic piston/cylinder 44.

Fig. 4 illustrates a modified hitch in accordance with the invention in which the socket member 50 carries a reaction strut 52 which, when the plug member 54 and the socket member 50 are interconnected, abuts against a thrust plate 56 secured to the A frame 58. In addition the A frame carries a catch link 62 pivotally attached to the A frame 58. The catch link 62 co-operates with a lifting pin 60 carried by the reaction strut 52. In operation, the implement may apply a turning moment to the tractor in a clockwise direction as indicated in Fig. 4 and the reaction strut 52 serves to direct this load to the plug member without subjecting the plug/socket connection to undue load. When it is required to tilt the implement, then the lifting pin 60 in conjunction with the catch link 62 facilitates lifting without undue loading of the plug/socket connection.

Fig. 5 illustrates one convenient method oftransferring drive from the tractor to the implement by way of a power take off. The arrangement comprises a splined shaft 64 which is journalled for rotation in bearings mounted on the plug member 56. The splined shaft co-operates with the power take off shaft of the tractor and carries a drive coupling 68 which comprises a square shaped opening 70. The opening 70 receives a drive peg 72 which introduces drive by means of a suitable transmission 74 to the implement. The drive peg 72 is complementary in shape with the opening 70 and has a tapered forward portion 76 which facilitates insertion into the opening 70. Preferably the drive coupling 68 is stidably mounted on the splined shaft and is spring biased in the axial direction towards the drive peg.

Although not shown, the plug and socket members may carry coupling means to facilitate interconnection of the hydraulic/air lines leading from the tractor to the implement when the hitch is coupled.

It is intended that the plug member is permanently attached to the three point mounting of the tractor and that the various agricultural implements are fitted with the socket member. When it is required to couple a particular implement to the tractor, then the tractor is manoeuvred towards the implement and by virtue of the tapered collar provided on the socket member and the tapered configuration of the spigot and socket, the spigot is guided into the socket to effect coupling automatically without the need to manhandle the implement or for the driver to get into and out of the tractor several times. When the spigot is received within the socket the catch means is actuated to lock the two members together. The facility for raising and lowering the plug member by virtue of its connection with the lower lifting links of the three point mounting linkage enable the plug member to be moved into the correct vertical alignment. The catch means may be activated automatically upon coupling by a mechanical linkage and a hydraulic cylinder may be used to release the catch means.

Whilst the hitch of the present invention has been described more particularly for coupling an implement to a tractor it is to be understood that the hitch of the present invention may be used with vehicles other than tractors. In this case the plug member will be provided with appropriate attachment means when the vehicle does not have a three point mounting arrangement.

Claims

1. A hitch for coupling implements to a towing vehicle comprises a plug member which is connectib[e with a socket member, and catch means for locking the plug and socket members when interconnected, one of the members having attachment means for connection with the towing vehicle and the other member being secured to the implement for connection with the towing vehicle, the socket member having a tapered collar for guiding the plug member into engagement therewith.

2. A hitch as claimed in claim 1, in which the plug member is provided with the attachment means, which comprise a pair of bottom pins disposed laterally of and on either side of the plug member and a top attachment link pin disposed above and between the pair of bottom pins.

3. A hitch as claimed in claim 2, in which the plug member comprises an A frame which carries the respective attachment pins and from which projects a tapered spigot which narrows in a direction away from the A frame.

4. A hitch as claimed in claim 3, in which the plug member is fabricated from sheet steel and the tapered spigot is hollow having a rectangular crosssection.

5. A hitch as claimed in claim 3 or claim 4, in which the socket member is secured to the implement to be towed and has a complementary shaped, tapered, rectangular socket into which the spigot is received, a tapered collar being disposed around the mouth of the socket and extending in a direction away from the socket.

6. A hitch as claimed in any of claims 1 to 5, in which the catch means comprises a pair of arms pivotally securedto the plug member and having a respective catch which projects through a respective opening in the plug member and is received in a respective opening in the socket member.

7. A hitch as claimed in any of claims 1 to 6, in which the plug member has drive means comprising a splined shafrfor engagement with the power take-off shaft of a tractor and which carries a drive coupling within which is received a tapered drive peg carried by the socket member and coupled with a drive shaft on the implement.

8. A hitch as claimed in claim 7, in which the drive coupling is a square shaped drive coupling.

9. A hitch as claimed in any of claims 1 to 8, which incorporates a coupling by means of which hydraulic/air lines from a tractor may be intercon nected to hydraulic and/or air lines to the implement when the coupling of the tractor to the implement is made.

10. A hitch as claimed in claim 1 and substantially as hereinbefore described with reference to any of Figs. 1 to 3,4 or 5 of the accompanying drawings.