GB2408669A

GB2408669A - A coupling device

Info

Publication number: GB2408669A
Application number: GB0328057A
Authority: GB
Inventors: Stanley Roberts
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-12-04
Filing date: 2003-12-04
Publication date: 2005-06-08
Anticipated expiration: 2023-12-04
Also published as: GB0328057D0; GB2408669B

Abstract

A drive coupling for interconnecting a drive-providing means 1 with a driven means 26 comprising a rotatable drive member connected or connectable to the drive-providing means for receiving drive therefrom and a rotatable driven member connected to or connectable to the driven means for receiving drive from the drive member to drive the driven means with said members being drivingly inter-engageable. The rotatable drive member is displaceable by displacing means for optionally displacing said drive member along its axis of rotation towards and into engagement with and away from and out of engagement with said driven member, and wherein the driving inter-engagement is provided by said driven means or drive means having at least three projections 40 equally spaced apart and equally spaced from said axis of rotation and by said drive means or driven means, respectively, having at least three recesses 2 or apertures equally spaced apart and equally spaced from said axis and being adapted to readily receive said projections. The projections and apertures are inter-engageable in driving interrelationship upon rotation of said drive means.

Description

A COUPLING DEVICE

The present invention relates to a drive coupling for interconnecting a drive-providing-apparatus with a driven implement attachmenVworking attachment for use with a lifting frame and a mounting frame thereof to enable ready mechanical attachment and dismounting of the implement attachment.

Many known couplings require for the interface coupling the use of splined shafts engaging in internally splined apertures which can be difficult to align and connect.

The present invention is particularly concerned with connections and couplings between tractors and agricultural implements (working attachments) to be connected and towed and powered thereby although may be used for other purposes and with other apparatus. The invention is particularly concerned with providing a simple and economic coupling having ease of coupling without splines for such.

The drive coupling of the invention may, for example, be used as a drive connection between the parts of an implement coupling device such as those disclosed in GB 1 110 361, US 3,871,463, GB 2 163 034 or EP 1,103, 171.

However, the present invention is particularly and preferably intended to be used with the coupling device of GB 2 381 729 wherein one part of the present drive coupling will be mounted on the lifting means to be connected to the three-point linkage or front loading arms or like of a vehicle such as a tractor with auxiliary drive means powered by the tractor, and the other part of the coupling will be mounted on mounting means connected to an implement or on the implement itself preferably connected or connectable to a gear box for driving the implement such as with implement attachments for tractors. However, the general principals of the coupling may be used for other purposes and with other apparatus.

GB 2 381 729 discloses a new and improved implement coupling device and the drive coupling of the present invention is primarily intended to be used therewith so as to have a rotatable drive member provided on the lifting means (12) with a rotatable drive member being driveably engageable with the power take-off shaft of a tractor when the lifting means (12) is connected to the three part linkage of the tractor and with a rotatable driven member mounted on the mounting means (6). The subject matter of GB 2 381 729 is incorporated herein by reference.

According to the present invention there is provided a drive coupling for interconnecting a drive-providing-apparatus (such as a tractor) with a driven implement (such as an agricultural implement attachable to a tractor), comprising a rotatable drive member (preferably a plate with apertures) mountable on the drive-providing apparatus for receiving drive therefrom and a rotatable driven member (preferably a plate with projections) mountable on the implement for receiving drive from the drive member to drive the implement, with said members being drivingly inter-engageable; wherein the rotatable drive member is also displaceable, preferably axially, by displacement means for optionally displacing the member, preferably along its axis of rotation, towards and into engagement with and away from and out of engagement with said driven member when said apparatus and implement are juxtaposed.

Control means will preferably be provided for actuating said displacement means and may comprise cam means movable with means for holding two parts of an implement coupling device together to activate the displacement means preferably and operable just after or just before said holding means engage or disengage said two parts.

The drive member and driven member will be operatively inter-engageable and preferably either the rotatable drive member or the rotatable driven member will preferably have at least three equally spaced apart projections such as pins and respectively, the rotatable driven member or rotatable drive member will preferably have at least three equally spaced apart apertures or recesses for receiving said projections in driving engagement upon rotation of said members.

The number of projections, preferably pins, whose axes extend parallel to the axis of rotation of the shaft, will depend on the size of the coupling and the forces involved. Preferably the apertures are adapted to receive the projections by being each of a larger diameter the downstream end relative to the direction of rotary movement and decrease in dimension away therefrom i.e. generally taper towards the upstream end and with respect to the direction of rotation; the larger end of the aperture being at the leading side of the aperture such that this in effect tapered aperture arrangement or adaptation enables said projections to relatively easily locate within the aperture and then as the aperture continues to move, the converging side walls and engage with their smaller dimension the projection in driving relationship. Further means to facilitate interconnection (and engagement with reverse relative movement) of the drive and driven members may be provided by each aperture or recess having a recessed or inclined surface at the leading end of each aperture or recess and running thereinto to facilitate location of projection into the recess or aperture.

Means for axially displacing the rotatable drive member towards said driven member will preferably be provided and preferably displacing along its axis of rotation and preferably be by way of spring means or spring action which will preferably operate shortly after the two members are juxtaposed i.e. preferably after the lifting means of the coupling of said drive-providing apparatus and the mounting means of the implement are juxtaposed/abutted and held together. Preferably the housing of the rotatable driven member will be mounted on a rubber mount on the implement attachment which will provide for some movement possibility to facilitate inter-engagement For simplicity, the subsequent description will be restricted to the apertures being located on the drive member and the projections on the driven member although a reverse arrangement is possible as are other inter- engagement possibilities.

The drive member is preferably mounted on a rotary shaft held between rotary bearings themselves mounted within a cylinder or tube which together are axially displaceable in telescopic manner therewith along the axis of rotation of the shaft and said cylinder is itself preferably mounted within a further guide tube to be linearly displaceable therein by means of action on an extension or projection itself preferably biased preferably by spring means to move the drive member towards the driven member for engagement therewith. Preferably a pivotably mounted displacing arm is provided to displace said extension and drive member away from said driven member against the bias of the spring means initially prior to the members being juxtaposed together and held in such position whereupon said arm may be released by rotation of a cam to enable the biasing means to engage the coupling members together. An axial inter- connection means will preferably be provided between the rotary shaft and the power-take-off shaft or other auxiliary drive means/power source of a tractor, for example, by means of a known telescopic coupling to permit for such movement whilst remaining in drive connection.

It is to be appreciated that the device of the present invention is primarily intended to be utilised with the implement coupling device of GB 2 381 729 and by way of example, the mounting frame (6) thereof will preferably have the driven member located within the space defined thereby and the lifting frame (12) will have the driven member located generally within the space defined thereby such that when the mounting frame (6) and lifting frame (12) are inter-engaged by the projections (17) in apertures (14,15) and lifted upwardly, the sides of the frames (10A,11) will move together and be juxtaposed/in abutment and then clamped together by the sliding clamp members (8,9). The displacement means for the clamps (8,9), will preferably be cam surface members (19,20) on a rotatable axle (21) and preferably such axle will also have a cam according to the present invention located thereon such that when the frames (6,12) are first put together, the cam will displace a pivotal displacing arm, for example, to act to displace the driven member away from the drive member of the invention and towards the tractor or like so as to compress the spring means and maintain such compression at least until the clamping means operate to hold the two mounting and lifting frames (6,12) together whereupon, with continued movement of the cam such then releases the pivotal arm to enable the spring biasing means to move the drive member (preferably in the form of a circular disc with three equally spaced apertures therein), towards the driven member (preferably a similar circular rotary disc with three equally spaced co-operating projections thereon) and together into inter-engagement wherein the apertures capture the projections and move to engage such at their preferably reduced width ends for driving the driven member and the drive train of the implement connected thereto. Conversely in reverse, the drive member is disengaged from the driven member of the implement by the cam re-engaging the pivotal arm shortly prior to the clamp members (8,9) being released for disconnection of the implement.

Also, according to the present invention there is provided in combination an implement coupling for coupling a detachable implement to the three point linkage of a tractor or other vehicle and/or to the front lifting or loading arms of a tractor or other vehicle, comprising at least one mounting means connected to or connectable to an implement to be raised by the vehicle, and one or more lifting means connected to or connectable to the front lifting arms and/or the three point linkage or linkages of the vehicle; wherein one of said mounting means or lifting means has engageable means engageable with engageable means of the other lifting means or mounting means respectively, such that when inter- engaged and the lifting means is raised, to the mounting means is raised, and releasable retaining means for holding the mounting means and lifting means together, and also provided a drive coupling for interconnecting a drive- providing-apparatus (such as a tractor) with a driven implement (such as an agricultural implement attachable to a tractor), comprising a rotatable drive member (preferably a plate with apertures) mountable on the drive-providing apparatus for receiving drive therefrom and a rotatable driven member (preferably a plate with projections) mountable on the implement for receiving drive from the drive member to drive the implement, with said members being drivingly inter-engageable; wherein preferably the rotatable drive member is displaceable, preferably axially, by displacement means for optionally displacing the driving member, preferably along its axis of rotation, towards and into engagement with and away from and out of engagement with said driven member when said mounting means and lifting means are juxtaposed and held together.

When commencing operation, the displacement means is preferably activated after the retaining means are engaged and when dismounting, the displacement means is operated to disengage the drive member and driven member prior to releasing the retaining means.

The implement coupling mounting means and lifting means will be so mounted on the implement and the tractor in the preferred arrangement and so shaped and dimensioned, that when the mounting means and lifting means abut and are held together, the drive and drive means are engaged. However, the displacing means which is preferably remotely operable from the cab initially displaces the drive means so that it is not engaged and, also prior to the drive and driven members being separated, the displacing means causes disengagement of the drive means.

Also, according to the present invention there is provided the implement coupling device as defined above with drive coupling means in combination with a tractor and connected to the lifting linkage and power-take-shaft thereof.

It is of advantage that springs or other compressible bias means the engagement rather than hydraulic power since damage can be thereby avoided.

The driven plate of the coupling does not need to have a flexible joint to supply coupling as it could advantageously be connected directly to the gear box of the driven implement. Preferably via a rubber mount with some movement tolerance to facilitate inter-engagement with the drive member.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an exploded perspective part schematic view of the drive part of a drive coupling viewed from the side of the drive apparatus i.e. normally a tractor to which it is to be connected; Fig. 2 is a vertical schematic section through the assembled drive means of the coupling; Fig. 2A is a perspective view of a drive shaft and displacing cam; Fig. 3 is an enlarged fragmentary detail part of the drive means shown in Fig. 2 viewed from the opposite side showing the rotary shaft mounted within rotary bearings with the bearings being fixedly mounted in an axial displaceable cylinder have a projection extending from the bottom thereof and running in a slot of the carrying housing; Fig. 4 is an exploded view of Fig. 3; Fig. 5 is a vertical schematic section through the driven part of the coupling which is to be mounted on the implement to be attached to a tractor.

Fig. 5A is a part end elevation from the right-hand side of Fig. 5.

Fig. 6 is a perspective view showing the driven member (left) and drive member (right) between mounting uprights and spaced apart and turned to show the end faces; Fig. 7 is a perspective view of the driven and drive members of Fig. 6 juxtaposed and inter-engaged with the axes of rotation alignment; Fig. 8 is a perspective view from the side where the implement to be attached is (not shown) showing the mounting member/implemenVframe of an implement coupling such as disclosed in GB 2 351 6729 with a driven member to be mounted on the implement, and the lifting member/tractor frame to be connected to a tractor with the drive member mounted centrally thereon; Figs. 9A and 9B are perspective views of the components of Fig. 8 from the tractor side - Fig. 9B including a pivotally mounted shaft (30) with a control cam (31); and Fig. 10 is a perspective view of the shaft and cam of Fig. 9B on its own with end cam surfaces for displacing clamping means (19,20 of GB 2,381,729 A) A drive coupling is shown in the drawings which is preferably intended to be incorporated with an implement coupling device such as disclosed in and covered by GB 2 381 729 although may be utilised with other arrangements.

Figs. 1 to 5 are partly schematic or simplified.

In the exploded view of Fig. 1 part of the drive coupling is illustrated and comprising a rotatable drive member in the form of a circular disc 1 having three equally spaced, identical apertures or slots 2 therein (only one shown in Fig. 1) with the apertures 2 tapering or reducing in dimension in an upstream direction with respect to the normal direction of rotation (arrow 3) of the disc 1. The disc 1 is securely mounted on a rotary shaft 4 to be rotatable therewith and shaft 4 is rotatably mounted within two sets of bearings 5,6 and held captive therein by circlips 7. The bearings 5,6 in turn are securely mounted in an axially displaceable coaxial cylinder 8 with aperture end wall 8A (only shown in Fig. 1) and which is slideable in telescopic manner in both directions along the axis of rotation 9 within an outer coaxial cylinder 10 and displaceable by means of force exerted forwardly/rearwardly on a downwardly extending projection 11 running in a slot 12 in the outer housing 10. The bearings 5,6 abut against steps 13,14 (only shown in Figs. 3 and 4) in displaceable cylinder 8 and held therein by circlips 7 on shaft 4, the end of shaft 4 is splined at 4A for connection to the PTO shaft of a tractor (not shown).

The outer cylinder 10 is secured between two vertical uprights 15,16 by welding with rod connectors 18 and which uprightly in the embodiment of Figs. 8 and 9 are secured centrally to a lifting frame 17 (centrally of 12 or 12A in GB 2 381 729) of an implement coupling which is to be mounted on the three point lifting linkage of a tractor (not shown).

Spring biasing means 19,20 are located either side of the outer cylinder 10 and each comprise a rod 21 with an enlarged disc-like head 21a at one end slideable in a cylinder 22 and biased by springs 23 to move to the left in Fig. 1 i.e. to be urged towards the rotary plate disc 1 and with said rods 21 extending through a guide aperture in the cylinder end 22A (against which the end of compression spring 23 abuts) and through apertures 24A in a displacing bar 24 and is held therein by nuts 25 on threaded ends of rods 21 so that the bar 24 and rods 21 move together. The horizontal displacing bar 24 thus interconnects the two spring biasing means 19,20 so as to be moved thereby in one direction whereupon it abuts against centrally located, downwardly extending projection 11. The spring biasing means 19,20 move projection in slot 12 also thus move cylinder 8 and thus shaft 4 and disc 2 axially to the left in Figs. 1 and 2, for example, i.e. away from the tractor and towards the other part, the driven part or member 20 of the drive coupling as will be described later. The bar 24 is guided in cut-outs 27 in the uprights 15, 16.

A driven means or member 26 shown in Figs. 5 to 9 whilst is to be located on an implement (not shown) which is to be attached to the tractor, will preferably be connected to the drive train thereof e.g. gearbox, of the implement and preferably be located generally in the space defined by the implement mounting frame 27. Frame 27 has apertures 28 for receiving projections 29 of the lifting frame 17 which when engaged and raised, cause faces 17A and 27A to abut or be juxtaposed and then two spaced clamping means (41 in Fig. 9B) are engaged by cam surfaces 30A,30B on either side of the frame 17,27 to hold faces 17A and 27A together (see GB 2 381 729). The clamping means 41 are operated by cam surfaces 30A,30B on a pivotally mounted rotary shaft 30 (see Figs. 9B and Fig. 10) running parallel to the lower frame part 17B on the tractor side and may be rotated by hydraulic means (not shown). This rotary shaft 30 has a central cam projection 31 which will be so located on the shaft 30 relative to the effective clamping position of said cam surfaces 30A,30B, such that cam 31 will only act to displace a displacing arm 32 pivotally mounted between its ends on axle 33 once the clamping cam surfaces have clamped frames 17 and 27 together and vice versa.

When the lower end 32A of arm 32 is acted on by cam 31 to move it clockwise in Fig. 2, the upper end 32B pushes projection 11 against displacing bar 24 causing such to be displaced to the right and against the bias action of springs 23. This results in displacement of shaft 4 and disc 1 away from driven member 26. On release by cam 31, the springs 23 via rods 21, bar 24 and projection 11, cylinder 8 and shaft 4, return the driving disc 1 back into engagement with the drive member 26 as will be described.

The axial displacement of shaft 4 when connected to the P.T.O. shaft or other auxiliary drive means, is enabled by suitable known means, such as a telescopic coupling.

The driven part or member 26 comprises a disc 33 fixed on the end of a rotary shaft 34 to rotate therewith and shaft 34 has splines to connect with the drive of the implement (not shown). Shaft 34 is rotatably mounted on rotary bearings 35,36 retainedly mounted against steps/shoulders 57A,57B in cylinder 37 itself secured in housing 38 having side securing frames 39 for mounting on rubber resilient mounts (not shown) with play for facilitating coupling with disc 1.

The disc 33 has three equally spaced rod-like/cylindrical projections or engaging pins 40 at the same radial distance as each other from the centre and axis of rotation 39 (similar to apertures 2) which when engaged with disc 1 is aligned with axis 9.

When the axes 39 and 9 are aligned and the discs 1,33 are brought together by the spring biasing means 19,.20, the apertures 2 of disc 1 which is not yet being rotated by the tractor will engage and capture the pins 40 or, if the pins 40 are not aligned with the apertures 40, they will be abutted by surface of disc 1 and then upon rotation of disc 1, they will be captured by the apertures.

When the disc 1 is caused to be rotated after engagement, the disc 33 on shaft 34 is caused to rotate thus driving the mechanism of the implement to which it is connected in use. As mentioned, the elongate aperture 2 are large at one end to facilitate such initial location around the pins 40 and then, with continued rotation, the apertures 2 engage the pins more closely at their reduced-dimension ends to drive such.

Thus, the disc 1 is normally biased in a direction away from the uprights 15,16 and into engagement with disc 33 i.e. towards the disc 33 of the driven member 26 when juxtaposed. However, during juxtaposition of the drive and driven members 1,33 and prior to such being inter-engaged, the displacing bar 24 will have been moved rearwardly towards the tractor by means of the pivotably mounted arm 32 which is acted upon at its opposite lower end 32A by the cam 31 on the rotatable clamp means displacing shaft 30. Thus, when the coupling parts 17,27 have been clamped together, the cam 31 then rotates, on continuous movement of shaft 30, to release the pressure on the lower end 32A of the displacing arm 32 enabling the spring bias means 19,20 to push the enlarged ends 21A,21B thereof and rods 21 forwardly and hence the disc 1 of the drive of the member forwardly along its axis of rotation 9 (but not yet rotating) a consequence of it previously having been connected to the operating drive shaft of the tractor, for example, such that the disc 1 then contacts the pins of the disc 31 to be driven and with commencement of rotation, if not already engaged, such will cause such pins 31 to be engaged in the tapered apertures 2 thereby causing the connected implement to be driven. Also, each aperture 2 has a rounded hollow or a recessed or inclined surface 2A at the leading end of each aperture or recess and running thereinto to facilitate location of projection into the recess or aperture and to facilitate disengagement of the pins especially when the drive is stopped and the movement of the driven implement drive train continues for a while.

For disengagement, the mentioned cam means 31 on the drive shaft 30 of the clamping means is initially moved to act on the displacing arm 32 to pivot and move such so as to disengage the drive and driven members 1,22 and, with continued movement of the shaft 30, the clamping means are caused to release the parts 1,3 of the coupling device whereupon then the implement coupling parts 17,27 may be disengaged as desired by manoeuvring the tractor or the like.

When in combination with the implement coupling device, the clamping of the two parts thereof together and then the release to enable the biasing means to urge the drive and driven members together is preferably effected one after the other but as a continuous operation with the continuous rotation of the shaft 30 - thus, in effect, as a single control operation.

It will be appreciated that a very simple and effective and reliable coupling is provided, which is robust and economic to produce and can be operated from the cab of a tractor or like.

The coupling does not use splines for the actual coupling and the free ends of the projections e.g. pins, face towards the older coupling when uncoupled and are spaced from the connected supporting rotary shaft.

According to the aspect of the invention there is provided a drive coupling for interconnecting a drive-providing means with a driven means comprising a rotatable drive member connected or connectable to the driveproviding means for receiving drive therefrom and a rotatable driven member connected to or connectable to the driven means for receiving drive from the drive member to drive the driven means with said members being drivingly inter- engageable; wherein the rotatable drive member is displaceable by displacing means for optionally displacing said drive member along its axis of rotation towards and into engagement with and away from and out of engagement with said driven member, and wherein the driving inter- engagement is provided by said driven means or drive means having at least three projections equally spaced apart and equally spaced from said axis of rotation and by said drive means or driven means, respectively, having at least three recesses or apertures equally spaced apart and equally spaced from said axis and being shaped and/or dimensioned as to receive said three projections in driving interrelationship upon rotation of said drive means.

Claims

1. A drive coupling for interconnecting a drive-providing means with a driven means comprising a rotatable drive member connected or connectable to the drive-providing means for receiving drive therefrom and a rotatable driven member connected to or connectable to the driven means for receiving drive from the drive member to drive the driven means with said members being drivingly inter-engageable; wherein the rotatable drive member is displaceable by displacing means for optionally displacing said drive member along its axis of rotation towards and into engagement with and away from and out of engagement with said driven member, and wherein the driving inter-engagement is provided by said driven means or drive means having at least three projections equally spaced apart and equally spaced from said axis of rotation and by said drive means or driven means, respectively, having at least three recesses or apertures equally spaced apart and equally spaced from said axis and being adapted to readily receive said projections, with said projections and apertures being inter-engageable in driving interrelationship upon rotation of said drive means.

2. A drive coupling as claimed in claim 1, in which the member in which the recesses or apertures are provided has a recessed or inclined surface at the leading end of each aperture or recess and running thereinto to facilitate location of projection into the recess or aperture.

3. A drive coupling as claimed in claim 1 or 2, in which said recesses or apertures are shaped and/or dimensioned as to receive any one of said three projections each of said recess or aperture is elongate and each of a larger dimension at the downstream end relative to the direction of rotary movement, and decrease in dimension away therefrom i.e. generally taper towards the upstream end with respect to the direction of rotation such that the larger end of the aperture being at the leading side of the aperture on rotation such that each aperture enables said projections to be readily located within the larger end thereof and then as the projection or aperture rotates the converging side walls and end wall engage with their smaller dimension the projections in driving relationship.

4. A drive coupling as claimed in any of claims 1 to 3, in which the displacing means for axially displacing the rotatable drive member towards said driven member comprise spring means or spring action or other biasing means and lever means or other further displacing means are provided for displacing the rotatable drive means against the force of the spring means or other biasing means and are operable by control means.

5. A drive coupling for interconnecting a drive-providing-apparatus (such as a tractor) with a driven implement (such as a driven agricultural implemenVmachine attachable to a tractor), comprising a rotatable drive member mountable on the drive-providing apparatus for receiving drive therefrom and a rotatable driven member mountable on the implement for receiving drive from the drive member to drive the implement, with said members having mechanically abutting or abuttable surfaces which are adapted to be readily drivingly inter-engageable; wherein the rotatable drive member is axially displaceable by displacement means for optionally displacing the member, along its axis of rotation, towards and into engagement with and away from and out of engagement with said driven member when said apparatus and implement are juxtaposed.

6. A coupling as claimed in claim 5, in which respectively, the driving member or driven member is a plate with apertures or recesses and the driven member or drive member is a plate with projections.

7. A coupling as claimed in claim 4, 5 or 6, in which control means are provided for actuating said displacement means and comprise cam means movable with means for holding two parts of an implement coupling device together to activate the displacement means.

8. A coupling as claimed in any of claims 5 to 7, in which the control means are such as to be operable just after or just before said holding means engage or disengage said two parts when in combination therewith.

9. A coupling as claimed in any of claims 5 to 8, in which the drive member and driven member are operatively mechanically inter-engageable and either the rotatable drive member or the rotatable driven member has at least three equally spaced apart projections equally spaced from the axis of rotation and, respectively, the rotatable driven member or rotatable drive member has at least three equally spaced apart apertures or recesses for receiving said projections in driving engagement.

10. A coupling as claimed in claim 9, in which said apertures are elongate.

11. A coupling as claimed in claim 10, in which each aperture is adapted to readily receive a projection by being of a larger diameter at one end, the downstream end relative to the direction of rotary movement, and decreases in dimension away therefrom i.e. generally tapers towards the upstream end and with respect to the direction of rotation; the larger end of the aperture being at the leading side of the aperture such that this tapered aperture enables said projections (such as pins) to be relatively easily located within the aperture and then, as the aperture relative movement between the pin and the converging side walls continues, engage the projection with their smaller dimension in driving relationship.

12. A coupling as claimed in any of claims 5 to 11, in which there is/are provided biasing means for axially displacing the rotatable drive member towards said driven member.

13. A coupling as claimed in claim 12, in which the displacement is by way of spring means or spring action.

14. A coupling as claimed in claim 12 or 13, in which the control means is operable such that the biasing displacing means are enabled to operate shortly after the two members are juxtaposed.

15. A coupling wherein combination with an implement and tractor as claimed in claim 14, in which the displacing means operate after the lifting means of the coupling of said drive-providing apparatus and the mounting means of the implement are juxtaposed/abutted and held together.

16. A coupling as claimed in any of claims 5 to 15, in which a housing for the driven member is mounted on a rubber mount on the implement attachment to provide some freedom of movemenVplay to facilitate inter- engagement of the projections and recesses or apertures.

17. A coupling as claimed in any of claims 5 to 16, in which the apertures are in the drive member and the projections are on the driven member.

18. A coupling as claimed in any of clams 5 to 17, in which the drive member is mounted on a rotary shaft held between rotary bearings themselves mounted within a cylinder or tube which together are axially displaceable therewith along the axis of rotation of the shaft.

19. A coupling as claimed in claim 18, in which said cylinder is itself slidably mounted within a further guide tube to be linearly displaceable therein by means of pressure action on an extension or projection.

20. A coupling as claimed in claim 19, in which said extension or projection is urgeable by biasing means to move the drive member towards the driven member for engagement therewith.

21. A coupling as claimed in claim 19 at least, in which a pivotably mounted displacing arm is provided and operable by control means to displace said extension and drive member away from said driven member against the biasing means (preferably the spring means) initially prior to the drive and driven members being juxtaposed and held together in such position.

22. A coupling when in combination with an implement coupling and as claimed in claim 21 in which the displacing arm and is releasable by rotation of a cam forming part of the control means to enable the biasing means to urge the coupling members together.

23. A coupling as claimed in at least claim 18 in use, in which an axial inter- connection means is provided between the rotary shaft and the power-take- off shaft of a tractor, (for example, by means of a known telescopic coupling) to permit for such movement whilst remaining in driving connection.

24. A coupling device as claimed in any of claims 1 to 23, in combination with an implement coupling device, wherein a mounting frame thereof has the driven member located within a space defined thereby or adjacent thereto on the implement and a lifting frame has the driven member located generally within the space defined thereby or adjacent thereto such that when the mounting frame and lifting frame are inter-engaged by the projections in the apertures and lifted upwardly, the sides of the frames move together to be juxtaposed/in abutment and then clamped together by clamp members.

25. A coupling as claimed in claim 25, in which the displacement means for the clamps are cam surface members on a rotatable axle, said axle has a cam located thereon forming control means such that when the frames are first put together, said cam is rotatable to displace a pivotal displacing arm to act to displace the driven member away from the drive member (and towards the tractor or like) so as to compress spring means or other biasing means and maintain such compression at least until the clamping means operate to hold the two mounting and lifting frames (6,12) together whereupon, with continued movement of the cam such then releases the pivotal arm to enable the spring biasing means to move the drive member (preferably in the form of a circular disc with at least three equally spaced apertures therein), towards the driven member (preferably a similar circular rotary disc with at least three equally spaced co- operating projections thereon) and together into inter-engagement wherein the apertures capture the projections and move to engage such (at their preferably reduced width ends) for driving the driven member and the drive train of the implement connected thereto.

26. A combination as claimed in claim 25, wherein the drive member is disengaged from the driven member of the implement by rotation of the cam re- engaging the pivotal arm shortly prior to the clamp members being released for disconnection of the implement.

27. In combination an implement coupling for coupling a detachable implement to the three point linkage of a tractor or other vehicle and/or to the front lifting or loading arms of a tractor or other vehicle, comprising at least one mounting means connected to or connectable to an implement to be raised by the vehicle, and one or more lifting means connected to or connectable to the front lifting arms and/or the three point linkage or linkages of the vehicle; wherein one of said mounting means or lifting means has engageable means engageable with engageable means of the other lifting means or mounting means respectively, such that when inter-engaged and the lifting means is raised, to the mounting means is raised, and releasable retaining means for holding the mounting means and lifting means together, and a drive coupling for drive interconnection a drive-providing-apparatus (such as a tractor) with a driven implement (such as an agricultural implement attachable to a tractor) interconnectable by said implement coupling comprising a rotatable drive member (preferably a plate with apertures) mountable on the drive-providing apparatus for receiving drive therefrom and a rotatable driven member (preferably a plate with projections) mountable on the implement for receiving drive from the drive member to drive the implement, with said members being drivingly inter-engageabie; wherein the rotatable drive member is displaceable (preferably axially) by displacement means for optionally displacing the driving member (preferably along its axis of rotation) towards and into engagement with and away from and out of engagement with said driven member when said mounting means and lifting means are juxtaposed and held together.

28. A combination as claimed in claim 27, whenever in combination with a tractor or like and a drive implement attachment, in which when commencing operation, the displacement means is activated after the retaining means are engaged and when dismounting, the displacement means is operated to disengage the drive member and driven member prior to releasing the retaining means.

29. A drive coupling substantially as herein described with reference to the accompanying drawings.

29. A combination as claimed in claim 27 or claim 28, in which the implement coupling mounting means and lifting means are such that when mounted on the implement and the tractor and are so shaped and/or dimensioned, that when the mounting means and lifting means abut and are held together, the drive means and driven means are engaged.

30. A combination as claimed in claim 29, in which the displacing means is operable from the cab i.e. remotely and initially displaces the drive means so as to be engaged and prior to the drive and driven member being separated causing the disengagement of the drive means.

31. An implement coupling device as claimed in any of claims 1 to 30 /with drive coupling means in combination with a tractor and connected to the lifting linkage and power-take-shaft thereof or front loading arm and auxiliary drive means.

32. A drive coupling substantially as herein described with reference to the accompanying drawings.

Amendments to the claims have been filed as follows

5. A drive coupling for interconnecting a drive-providing-apparatus (such as a tractor) with a driven implement (such as a driven agricultural implemenVmachine attachable to a tractor), comprising a rotatable drive member mountable on the drive-providing apparatus for receiving drive therefrom and a rotatable driven member mountable on the implement for receiving drive from the drive member to drive the implement, with said members having mechanically abutting or abuttable surfaces which are adapted to be readily drivingly inter-engageable by said driven member or drive member having at least three projections equally spaced apart and equally spaced from said axis of rotation and by said drive member or driven member, respectively, having at least three recesses or apertures equally spaced apart and equally spaced from said axis and being adapted to readily receive said projections, with said projections and apertures being inter-engageable in driving interrelationship upon rotation of said drive member; wherein the rotatable drive member is axially displaceable by displacement means for optionally displacing the member, along its axis of l, ; as rotation, towards and into engagement with an away from and out of engagement with said driven member when said apparatus and implement are juxtaposed; and wherein the apertures are elongate and each aperture is adapted to readily receive a projection by being of a larger diameter at one end, the downstream end relative to the direction of rotary movement, and decreases in dimension away therefrom i.e. generally tapers towards the upstream end and with respect to the direction of rotation; the larger end of the aperture being at the leading side of the aperture such that this tapered aperture enables said projections (such as pins) to be relatively easily located within the aperture and then, as the aperture relative movement between the pin and the converging side walls continues, engage the projection with their smaller dimension in driving relationship.

9. A coupling as claimed in any of claims 5 to 8, in which there is/are provided biasing means for axially displacing the rotatable drive member towards said driven member.

10. A coupling as claimed in claim 9, in which the displacement is by way of spring means or spring action.

11. A coupling as claimed in claim 9 or 10, in which the control means is operable such that the biasing displacing means are enabled to operate shortly after the two members are juxtaposed.

12. A coupling wherein combination with an implement and tractor as claimed in claim 11, in which the displacing means operate after the lifting means of the coupling of said drive-providing apparatus and the mounting means of the implement are juxtaposed/abutted and held together.

13. A coupling as claimed in any of claims 5 to 12, in which a housing for the driven member is mounted on a rubber mount on the implement attachment to provide some freedom of movemenVplay to facilitate inter- engagement of the projections and recesses or apertures.

14. A coupling as claimed in any of claims 5 to 13, in which the apertures are in the drive member and the projections are on the driven member.

15. A coupling as claimed in any of clams 5 to 14, in which the drive member is mounted on a rotary shaft held between rotary bearings themselves mounted within a cylinder or tube which together are axially displaceable therewith along the axis of rotation of the shaft.

16. A coupling as claimed in claim 15, in which said cylinder is itself slidably mounted within a further guide tube to be linearly displaceable therein by means of pressure action on an extension or projection. )

17. A coupling as claimed in claim 16, in which said extension or projection is urgeable by biasing means to move the drive member towards the driven member for engagement therewith.

18. A coupling as claimed in claim 16 at least, in which a pivotably mounted displacing arm is provided and operable by control means to displace said extension and drive member away from said driven member against the biasing means (preferably the spring means) initially prior to the drive and driven members being juxtaposed and held together in such position.

19. A coupling when in combination with an implement coupling as claimed in claim 18 in which the displacing arm and is releasable by rotation of a cam forming part of the control means to enable the biasing means to urge the coupling members together.

20. A coupling as claimed in at least claim 15 in use, in which an axial inter- connection means is provided between the rotary shaft and the power-take- off shaft of a tractor, (for example, by means of a known telescopic coupling) to permit for such movement whilst remaining in driving connection.

21. A coupling device as claimed in any of claims 1 to 20, in combination with an implement coupling device, wherein a mounting frame thereof has the driven member located within a space defined thereby or adjacent thereto on the implement and a lifting frame has the driven member located generally within the space defined thereby or adjacent thereto such that when the mounting frame and lifting frame are inter-engaged by the projections in the apertures and lifted upwardly, the sides of the frames move together to be juxtaposed/in abutment and then clamped together by clamp members.

22. A coupling as claimed in claim 21, in which the displacement means for the clamps are cam surface members on a rotatable axle, said axle has a cam located thereon forming control means such that when the frames are first put together, said cam is rotatable to displace a pivotal displacing arm to act to displace the driven member away from the drive member (and towards the tractor or like) so as to compress spring means or other biasing means and maintain such compression at least until the clamping means operate to hold the two mounting and lifting frames (6,12) together whereupon, with continued movement of the cam such then releases the pivotal arm to enable the spring biasing means to move the drive member (preferably in the form of a circular disc with at least three equally spaced apertures therein), towards the driven member (preferably a similar circular rotary disc with at least three equally spaced co- operating projections thereon) and together into inter-engagement wherein the apertures capture the projections and move to engage such (at their preferably reduced width ends) for driving the driven member and the drive train of the implement connected thereto.

23. A coupling as claimed in claim 21 or 22, wherein the drive member is disengaged from the driven member of the implement by rotation of the cam re- engaging the pivotal arm shortly prior to the clamp members being released for disconnection of the implement.

24. In combination an implement coupling for coupling a detachable implement to the three point linkage of a tractor or other vehicle and/or to the front lifting or loading arms of a tractor or other vehicle, comprising at least one mounting means connected to or connectable to an implement to be raised by the vehicle, and one or more lifting means connected to or connectable to the front lifting amms and/or the three point linkage or linkages of the vehicle; wherein one of said mounting means or lifting means has engageable means engageable with engageable means of the other lifting means or mounting means respectively, such that when inter-engaged and the lifting means is raised, the mounting means is raised, and releasable retaining means for holding the mounting means and lifting means together, and a drive coupling as claimed in any of claims 15 to 23, for drive interconnection of a drive-providing- apparatus (such as a tractor) with a driven implement (such as an agricultural implement attachable to a tractor) interconnectable by said implement coupling comprising a rotatable drive member (preferably a plate with apertures) mountable on the drive-providing apparatus for receiving drive therefrom and a rotatable driven member (preferably a plate with projections) mountable on the implement for receiving drive from the drive member to drive the implement, with said members being drivingly inter-engageable; wherein the rotatable drive member is displaceable (preferably axially) by displacement means for optionally displacing the driving member (preferably along its axis of rotation) towards and into engagement with and away from and out of engagement with said driven member when said mounting means and lifting means are juxtaposed and held together.

25. A combination as claimed in claim 24, whenever in combination with a tractor or like and a drive implement attachment, in which when commencing operation, the displacement means is activated after the retaining means are engaged and when dismounting, the displacement means is operated to disengage the drive member and driven member prior to releasing the retaining means.

26. A combination as claimed in claim 24 or claim 25, in which the implement coupling mounting means and lifting means are such that when mounted on the implement and the tractor and are so shaped and/or dimensioned, that when the mounting means and lifting means abut and are held together, the drive means and driven means are engaged.

27. A combination as claimed in claim 26, in which the displacing means is operable from the cab i.e. remotely and initially displaces the drive means so as to be engaged and prior to the drive and driven member being separated causing the disengagement of the drive means.

28. An implement coupling device as claimed in any of claims 1 to 27 with drive coupling means in combination with a tractor and connected to the lifting linkage and power-take-shaft thereof or front loading arm and auxiliary drive means.