GB2163034A - Improvements in or relating to automatic implement hitches - Google Patents

Abstract

A coupling for use in automatically coupling a tractor to an implement comprises substantially complimentary shaped, releasably engageable first and second coupling members (3, 5) adapted for connection with the three point linkage of a tractor and an implement, respectively, and each of inverted U-shape.The free end regions of the arms (11, 13) of the first coupling member (3) carry an abutment surface (43) with which the free end regions of the arms (27, 29) of the second coupling member (5) engage. Catch means (7) are carried by each of the free ends of the member (3) for co-operating engagement with the member (5) and fixed means (9) are positioned on the member (5) for releasably engaging the member (3). Guide means are carried by the coupling members (3, 5) for guiding them into cooperating engagement, and actuating means (89) are provided for the catch means (7) for engaging and disengaging the catch means (7) with complimentary locating spigots on the second coupling member (5). <IMAGE>

Description

SPECIFICATION Improvements in or relating to automatic implement hitches The present invention relates to automatic implement hitches. More particularly the present invention relates to automatic implement hitches for coupling implements to tractors.

It is an aim of the present invention to provide a coupling by means of which an implement can be automatically coupled to a tractor without the necessity for the tractor operator to manhandle the implement into co-operation with the tractor linkages. It is a further aim to produce a standard coupling which can be fitted to a large number of different implements having individually designed attachment linkages. It is a still further aim to provide a simple and effective catch means and simple guide means. It is a still further aim to provide a coupling which has a relatively short overall length.

According to the present invention there is provided an implement coupling for use in automatically coupling a tractor to an implement, said implement coupling comprising substantially complimentary shaped, releasably engageable first and second coupling members which are adapted for connection with the three point linkage of a tractor and an implement, respectively, each of the first and second coupling members being in the form of an inverted U-shaped member and the free ends of the first coupling member carrying an abutment surface with which the free ends of the second coupling member are adapted to engage when the first and second coupling members are coupled together, catch means carried by each of the free ends of the first or second coupling member for co-operating engagement with the other of the first and second coupling members, fixed means positioned at the base of the 'U' of the first and second U-shaped coupling member for releasably engaging the base of the 'U' of the other of the first and second U-shaped coupling members, guide means carried by the first or second coupling member for guiding the two coupling members into co-operating engagement, and actuating means for the catch means for engaging and disengaging the catch means with complimentary locating spigots.

The first and second coupling members are preferably plate-like in nature as this results in a particularly compact axial construction which avoids imposing undesirable overhanging loads on the tractor.

The first and second coupling members have the advantages that they provide the necessary strength for the coupling and the U-shaped nature of these members leaves a space for the positioning of a power take-off transmission between the tractor and the implement.

In a preferred embodiment of the implement coupling of the present invention the catch means are carried on the free ends of the first U-shaped coupling member, which is to be connected to the tractor, for co-operating engagement with the free ends ofthe second U-shaped coupling member, which is to be attached to the implement.

As stated above, each free end of either the first or the second U-shaped coupling member carries catch means for co-operating engagement with the other of the first and second U-shaped coupling members. Preferably each of such catch means comprises two pivotable locking plates locate on laterally opposite sides of the respective free end.

The pivotable locking plates are pivotable about a generally vertical axis - or at least about an axis parallel to the plane of the coupling members. In their open position the pivotable locking plates constituting each pair of such plates diverge outwardly from each other and thereby act as an aid in guiding the first and second coupling members into correct engagement with each other.

When the catch means, carried by the free ends of the first or second U-shaped coupling members, comprise pivotable locking plates, each of the pivotable locking plates preferably has a recess therein, or a bore therethrough, and each of the free ends of the other of the first and second U-shaped coupling members preferably comprises two complimentary spigot pins such that each recess or bore on the pivotable locking plates on one of the coupling members engages with a respective spigot pin on the other of the coupling members. This arrangement of catch means provides a more rigid coupling than if the tractor and implement were coupled together by way of a single catch means.

In an alternative, but less preferred construction, the catch means may comprise pivotable hook members on the free ends of one of the first and second U-shaped coupling members, these pivotable hook members being arranged to engage with spigot members on the free ends of the other of the first and second U-shaped coupling members.

The fixed means, which is stated to be positioned at the base of the 'U' of the first or second U-shaped coupling member, is preferably positioned at the base of the 'U' of the first U-shaped coupling member which is itself to be attached to the tractor.

The fixed means preferably comprises a flange, which is attached to and extends outwardly from, the first or second coupling member and which has a retaining lip on the side of the flange remote from the coupling member to which the flange is attached. Such a flange and retaining lip, positioned on the base of the 'U' of the first or second U-shaped coupling member, will serve to releasably engage the base of the 'U' of the other of the first and second U-shaped coupling members since the underside of the flange will abut against the outer peripheral edge of the base of the 'U' of the Ushaped coupling member it is to releasably engage and the retaining lip will abut against that surface of the U-shaped coupling member it is to releasably engage remote from the coupling member carrying the flange and retaining lip.

The guide means for guiding the first and second coupling members into co-operating engagement may, for example, comprise two plates which are carried by the free arms of the 'U' of the first or second U-shaped coupling member, one of the plates being carried by one of free arms and the second of the plates being carried by the other of the free arms. These plates will converge in the direction away from the coupling member carrying them if they are located on the inner peripheral surface of the 'U' and will diverge in the direction away from the coupling member carrying them if they are located on the outer peripheral surface of the 'U'. Preferably the two plates are carried by the first U-shaped coupling member.

As an alternative to, or in addition to, the abovedescribed guide means comprising two converging or diverging plates, the implement coupling of the present invention may, for example, have guide means comprising a cylindrical member, secured to the base of the 'U' of one of the first and second of the U-shaped coupling members, and an inclined co-operating member, secured to the base of the 'U' of the other of the first and second U-shaped coupling members.The co-operating member comprises twd parallel, inclined bars which are spaced apart by a distance less than the diameter of cylindrical member such that, if the two coupling members approach one another out of vertical alignment, then one end of the cylindrical member will contact the two parallel bars and, as the two coupling members are brought closertogether, then the end of the cylindrical member contacting the two parallel bars will slide down the two parallel bars of the co-operating member and will thereby be guided by the co-operating member until the coupling members are in correct alignment.

Preferably the cylindrical member is secured to the second coupling member and the co-operating member is secured to the first coupling member.

The cylindrical member may be hollow solid. The parallel bars of the co-operating member may have any desired cross section, e.g. circulae, square or rectangular.

The means by which the first coupling member is to be attached to the three point linkage on a tractor may, for example, comprise a plurality of spaced holes in the region of the base of the 'U' of the Ushaped first coupling member for direct or indirect attachment to the upper link of the three point linkage, the plurality of spaced holes catering for differently positioned links of different tractors.

Further, the first coupling member may, for example, be attached to the two remaining links of the three point linkage on the tractor by providing each free end of the U-shaped first coupling member with two spaced apartflange members which are spaced to enable the respective lower links, or attachment points, of the three point tractor linkage to be received therebetween. Each of the spaced flange members will have a bore therein for receiving a mounting pin such that the two lower links on the tractor linkage can be secured to the free ends of the first coupling member by means of these mounting pins. Preferably, the bores in the flange members are such that variations in spacing of the links of the tractor linkage may be accommodated.However, it may alternatively be that a plurality of bores are present in each ofthe flange members to accommodate variations in the spacing of the lower links of the tractor linkage.

The means by which the second coupling member is to be attached to the three point linkage on an implement may, for example, be the same as the means described above for attachment of the first coupling member to the three point linkage on a tractor.

The various components of the implement coupling of the present invention are preferably made of steel.

The present invention will now be further described with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an implement coupling according to the present invention, with the first and second coupling members engaged; Fig. 2 is a perspective view of the first coupling member ofthe implement coupling illustrated in Fig. 1, the first coupling member being for attachment to a tractor and having the clamp means in the closed position; Fig. 3 is a view illustrating part of the operating means for the catch means present on the coupling member illustrated in Fig. 2, the view being taken in the direction of arrow A of Fig. 2 and illustrating the catch means in the closed position; Fig. 4 is a view similar to that illustrated in Fig. 5 but having the catch means in the open position;; Fig. 5 is a perspective view ofthe second coupling member of the implement coupling illustrated in Fig. 1, the coupling member being for attachment to an implement and the view illustrating the face of the second coupling member that contacts the first coupling mem be; when the two coupling members are releasably engaged; Fig. 6 is a perspective view of the second coupling member illustrated in Fig. 5 but illustrating the other face of that coupling member; Fig. 7 is a perspective view of a power take-off positioning device suitable for use in combination with the implement coupling of the present invention; and Fig. 8 is a perspective view of an alternative power take-off positioning device suitable for use in combination with the implement coupling of the present invention.

Referring to Figs. 1 to 6 of the accompanying drawings there is illustrated an implement coupling 1 for use. in automatically coupling an implement to a tractor. The implement coupling 1 has two parts, a first coupling member 3 and a second coupling member 5.

The first coupling member 3 is adapted to be secured to the three point linkage of a tractor, whilst the second coupling member 5 is adapted to be secured to the three point linkage of an implement.

The two coupling members 3 and 5 are adapted to be coupled together byway of catch means 7 and fixed retaining means 9.

The first coupling member 3 has an inverted Ushaped configuration with arm sections 11 and 13 and a base section 15. The first coupling member 3 comprises two plate-like members 17 and 19 which are spaced apart by means of intermediate members 21, 23 and 25. There are two intermediate members 21, one on arm section 11 and one on arm section 13, but in the drawings only the intermediate member 21 on arm section 13 is shown. Similarly, the second coupling member 5 has an inverted Ushaped configuration with arm sections 27 and 29 and a base section 31. The second coupling member 5 comprises two plate-like members 33 and 35 which are spaced apart by means of intermediate members 37 and 39. Fixed retaining means 9 also aids in the spacing of plate-like members 33 and 35.

When the two coupling members 3 and 5 are coupled together, the plate-like member 19 of the first coupling member 3 abuts against the plate like member 33 of the second coupling member 5. Also, the free ends of arm sections 11 and 13 of the first coupling member 3 carry attachment brackets 41 (the purpose of which will be described hereinafter) which project outwardly from the plane of the platelike member 11 and which have abutment surfaces 43. These abutment surfaces 43 abut against the free ends of the arm sections 27 and 29 of the second coupling member 5 and thereby aid in the correct alignment of the two coupling members 3 and 5 when they are being coupled together.

Two converging guide plates 45 are secured to the inner peripheral edge of the first coupling member 3, the main purpose of these guide plates 45 being to ensure correct alignment between the first coupling member 3 and the second coupling member 5 when the two coupling members 3 and 5 are brought into engagement with each other.

However, the guide plates 45 may also act as supporting members for a position device being for a power take-off transmission, the positioning device being secured to the guide members 45 at points 47 and also, if necessary, being secured to the arm sections 11 and 13.

An additional aid to ensure correct alignment of the second coupling member 5 with the first coupling member 3, particularly to ensure correct vertical alignment, is mounted on the base section 15 of the first coupling member 3 and the base section 31 of the second coupling member 5. This additional aid is in the form 2f a circular crosssection tube 49 which is open at one end 51 and closed at the other end 53.The closed end 53 has a curved surface such that, if the second coupling member 5 is too high when the two coupling members 3 and 5 are brought together, the end 53 of tube 49 will contact parallel strip members 55 and 57, which are mounted on the base section 15 of the first coupling member 3 by way of U-shaped strip member 59, and will be guided by these strip members 55 and 57 into the space 61 formed between the 'U' of the U-shaped strip member 59. In order to allow this procedure to occur the strip members 55 and 57 are spaced apart by a distance which is less than the diameter of tube 49 and the arm sections of the U-shaped strip member 59 are spaced apart by a distance greater than the diameter of the tube 49.Further, the base of the 'U' of the U shaped strip member 59 must be such that it does not interfere with the smooth movement of the end 53 of tube 49 from the strip members 55 and 57 to the space 61 between the 'U' of the U-shaped strip member 59.

The fixed retaining means 9 is in the form of a flange 63 which extends outwardly from the base section 31 of the second coupling member 5, the flange 63 having lip 65 on its edge remote from the base section 31. From Fig. it can be seen that, when the two coupling members 3 and 5 are coupled together, the flange 63 and retaining lip 65 releasably engage the base section 31 of the second coupling member 5 and thereby aid in retaining the two coupling members 3 and 5 coupled.tpgether.

The catch means 7 comprise two pairs of flange members 67 which are pivotally mounted on the free ends of the first coupling member 3, one pair of flange members 67 being pivotally mounted on one of the free ends of coupling member 3 and the other pair of flange members 67 being pivotally mounted on the other free end of the same coupling member.

Each flange member 67 has a recess or bore 69 therein which releasably engages a corresponding spigot pin 71 on the second coupling member 5, there being a total of four spigot pins 71 on the second coupling member 5 (only two such spigot pins being shown).

The means by which the flange members 67 engage and disengage the corresponding spigot pins 71 is operated manually and comprises a pivot member 73, one end 75 of which is pivotally mounted between the strip members 55 and 57. The other end of pivot member 73 has rotatably mounted thereon two rods 77 and i9. The lower end of rod 77 is pivotally attached to two rods 81 and 83, and the lower end of rod 79 is pivotally attached to two rods 85 and 87. The ends of rods 77, 81 and 83 which are pivotally connected together, and the ends of rods 79, 85 and 87 which are pivotally connected together, are forked as shown in Fig. 1.

The ends of rods 81,83,85 and 87 which are not pivotally attached to either of rods 77 or 79 are pivotally attached to the flange members 67. A handle 89 is secured to pivot member 73 and this handle 89 is adjustable in height by means of adjustment device 91 which comprises two parallel plates 93 and 95, each of which has a plurality of spaced holes therein, and a pin (not shown) which passes through handle 89 and one of the spaced holes in each of the plates 93 and 95.

When it is desired to engage the catch means 7 with the spigot pins 71, the handle 89 is moved in a downwards direction, which, in turn, pushes the rods 77 and 79 in a downwards direction. This downwards movement of rods 77 and 79 causes rods 81,83,85 and 87 to move from an inclined position, through a horizontal position, and to an inclined position below the horizontal position, thereby resulting in the flange members 67 being pivoted such that they engage with the respective spigot pins 71 (see Fig. 3). If any load is applied to flange members 67 then this will tend to cause the rods 81,83,85 and 87 to move further downwards and abut against an end stop (not shown) thereby preventing the flange members 67 from disengaging the spigot pins 71.

To disengage the catch means 7 from the spigot pins 71, the handle 89 is moved in an upwards direction which, in turn, causes the rods 77 and 79 to move in an upwards direction.This upwards movement of rods 77 and 79 causes rods 81, 83,85 and 87 to move from the horizontal position back to their inclined position and results in the flange members 67 being pivoted out of engagement with the spigot pins 71 (see Fig. 4).

If desired a locking device may be provided on pivot member 73, this locking device being in the form of a ball bearing which is mounted on one side of pivot member 73 and is biassed, e.g. by means of a spring, into engagement with a recess in the adjacent surface of one of the parallel strip members 55,57. If preferred the locking device may comprise two ball bearings mounted on opposite sides of the pivot member 73 and each being biassed, e.g. by means of a spring or springs, into engagement with a respective recess in the strip members 55, 57.

The second coupling member 5 is adapted to be attached to the three point linkage of an implement and this is achieved by providing a plurality of spaced holes 97 on either side of a recess 99 (only one set of holes 97 shown), by means of which the upper link of the implement can be secured in position using a pin (not shown). Attachment brackets 101 are provided on the free ends of the second coupling member 5 and these are attached to the lower links of the implement linkage, again by means of pins (not shown). The attachment brackets 101 are slidably mounted on the free ends ofthe second coupling member 5 to accommodate various spacings of the lower links of the implement linkage.This slidable nature of the attachment brackets is achieved by bolting the attachment brackets 101 to blocks 103 through slots 105 in the free ends of the second coupling member 5.

The first coupling member is adapted to be attached to the three point linkage of a tractor and this is achieved by providing a plurality of spaced holes (not shown) on either side of a recess 107 by means of which the upper link of the tractor linkage can be secured in position by means of a pin (not shown). Attachment brackets 41 are provided on the free ends of the first coupling member 3 and these attachment brackets have holes therein which allow the lower links of the tractor linkage to be secured thereto by means of pins (not shown).

As a further aid in guiding the first and second coupling members into correct alignment with each other each block 103, slidably mounted on the second coupling member 5, has an upper surface 107 which is inclined downwardly in a direction away from the coupling member 5 such that when the two coupling members 3 and 5 are brought together the inclined surfaces 107 contact the edges 109 of the coupling member 3 and are guided thereby into correct alignment.

As can be seen from Figs. 1 to 6 ofthe accompanying drawings, the illustrated implement coupling is of particularly compact construction whilst providing the necessary strength for lifting purposes by provision of the abutment surfaces 43.

Furthermore, the U-shaped nature of the two coupling members 3 and 5 makes it possible to provide for automatic coupling of the power transmission which will be disposed within the space bounded by the arm sections and base section ofthe 'U' of each of the two coupling members 3 and 5.

The numerous mounting holes provided in the coupling members enable differently spaced tractor linkages and implement linkages to be catered for.

The use of the implement coupling of the present invention to couple an implement to a tractor results in the coupling member attached to the tractor reducing the overhang and thereby giving little or no difference to the loading on the tractor.

Preferring to Figs. 7 and 8 there is shown two embodiments of a positioning device for a power take-off transmission. In Fig. 7, the power take-off from the tractor is received within a bore 111 in a member 113 which is itself slidably disposed in a hole 115 in a member 117. The member 117 is slidable on two horizontal rods 119, which are fixed to the tractor or automatic coupling part. Thus, the power drive of the tractor can be aligned with the power take-up shaft on the implement, the positioning device provided horizontal and vertical movement of the drive shaft. The positioning device is fixed to the tractor or to the coupling member 3 such that the power drive is disposed in the area between the limbs of the coupling.

In the illustration, the member 117 has a bore 123 which receives the rod 119 and a recess 125 which receives the rod 121. The member 113 is provided with flange portions, which embrace the member 117, defining grooves locating the member 113 for sliding co-operation within the member 117. As an alternative, each groove may be replaced by a pair of annular sleeve members, or a single sleeve which is located on a bar interconnecting the part accommodating the bore 123 and the recess 125.

A further alternative is described in Fig. 8. A member 127 for receiving the drive shaft in a bore 129 is slidably disposed with respect to a plate member 131, for which purpose two bracket members 133, 135 are provided. The member 131 has an elongate hole 137 to accommodate movement of the drive shaft. The plate member 131 is likewise slidably received in brackets 139, 141 carried on a member 143 which is fixed to the tractor or coupling member 3. A rectangular hole 145 is formed in member 143 to accommodate movement of the drive shaft.

Thus, the positioning devices described enable the power drive shaft to be adjustably positioned for alignment with the drive shaft ofthe implement.

Preferably means is provided for displacing the respective plate members vertically and horizontally into the desired position.

Claims (23)

1. An implement coupling for use in automatically coupling a tractor to an implement, said implement coupling comprising substantially complimentary shaped, releasably engagable first and second coupling members which are adapted for connection with the three point linkage of a tractor and an implement, respectively, each of the first and second coupling members being in the form of an inverted U-shaped member and the free ends of the first coupling member carrying an abutment surface with which the free ends of the second coupling member are adapted to engage when the first and second coupling members are coupled together, catch means carried by each of the free ends of the first or second coupling member for co-operating engagement with the other of the first and second coupling members, fixed means positioned at the base of the 'U' of the first or second U-shaped coupling member for releasably engaging the base of the 'U' of the other of the first and second Ushaped coupling members, guide means carried by the first or second coupling member for guiding the two coupling members into co-operating engagement, and actuating means for the catch means for engaging and disengaging the catch means with complimentary locating spigots.

2. A coupling as claimed in claim 1, in which the first and second coupling members are plate-like in general construction.

3. A coupling as claimed in claim 1 or claim 2, in which the catch means are carried on the free end regions of the first U-shaped coupling member which is to be mounted in the tractor.

4. A coupling as claimed in any one of claims 1 to 3, in which each catch means comprises two pivotable locking plates located on laterally opposite sides of the respective free end region of the coupling member, the locking plates being pivotable about an axis parallel to the plane of the coupling member.

5. A coupling as claimed in claim 4, in which the locking plates of each pair of locking plates, diverge outwardly from each other in the open catch position, to thus act as a guide for the correct interengagement of the coupling members.

6. A coupling as claimed in claims 4 or 5, in which each locking plate has a recess or bore into which a spigot pin mounted on the other coupling member, can engage when the locking plates are moved to a closed catch position.

7. A coupling as claimed in any one of claims 1 to 3, in which the catch means comprises pivotable lock members on the free end regions of one of the coupling members, the pivotable lock members being arranged to engage with spigot members on the free end regions of the other coupling members when the coupling members are interengaged.

8. A coupling as claimed in any one of the preceding claims, in which said fixed means is mounted on the first coupling member which is to be mounted on the tractor.

9. A coupling as claimed in any one of the preceding claims, in which said fixed means comprises a flange which is attached to and extends outwardly from the coupling member to which it is attached, the flange having a retaining lip which releasably engages over an edge of the other coupling member when the coupling members are interengaged.

10. A coupling as claimed in any one of the preceding claims, in which said guide means comprises two plates which are carried by the arms of one of the U-shaped coupling members, one plate being mounted on each arm so as to project out of the plane of said one coupling member.

11. A coupling as claimed in claim 10, in which said plates are mounted on the adjacent inner surfaces of the U-shaped coupling member and converge in the direction away from said coupling member.

12. A coupling as claimed in claim 10, in which said plates are mounted on the outer surfaces of the U-shaped member and diverge in the direction away from said coupling member.

13. A coupling as claimed in either claim 11 or 12, in which the two plates are carried in the coupling member which is to be mounted on the tractor.

14. A coupling as claimed in any one of the preceding claims, in which the guide means comprises a cylindrical member secured to the base of one of the generally U-shaped coupling members, and an inclined co-operating member secured to the base of the other U-shaped coupling member, the co-operating member comprising two parallel, inclined bars which are spaced apart by a distance less than that the diameter of the cylindrical member, such that said bars will guide the cylindrical member on interengagement, to correctly align with the coupling members.

15. A coupling as claimed in any one of the preceding claims, in which one coupling member is provided with a plurality of spaced apart holes in the region of the base of the U-shaped configuration, for use in attaching the coupling member to one point of a three point linkage on a tractor or implement, and each arm of the coupling member has a flange member for attachment to one of the other two linkage points.

16. A coupling as claimed in claim 15, in which the flange members are adjustable in position on the coupling member.

17. A coupling as claimed in any one of claims 4,5 or6, in which the catch means are remotely operable by a linkage which connects with a manually operable control lever located on the base region of the generally U-shaped coupling member.

18. An implement coupling for use in automatically coupling a tractor to an implement, constructed substantially as hereinbefore described with reference to and as illustrated in Figs. 1 to 6 of the accompanying drawings.

19. An implement coupling as claimed in any one of the preceding claims, when in combination with a power take-off positioning device.

20. A coupling as claimed in claim 19, in which the power take-off positioning device comprises a member having a bore through which the power take-off can pass, said member being slidably mounted in an aperture in a further member, and said further member being adjustably supported on support means which can be secured to the tractor.

21. A coupling as claimed in claim 20, in which said support means are a pair of parallel bars, and said members are generally rectangular and planar.

22. A coupling as claimed in claim 20, in which said members and said support means, are each generally rectangular, and substantially planar members.

23. A power take-off and positioning device constructed substantially as hereinbefore described with reference to and as illustrated in Fig. 7 or Fig. 8 of the accompanying drawings.