GB2429195A

GB2429195A - A drawbar

Info

Publication number: GB2429195A
Application number: GB0616388A
Authority: GB
Inventors: Patrick Mccormick; Padraic Mccormick
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-18
Filing date: 2006-08-18
Publication date: 2007-02-21
Anticipated expiration: 2026-08-18
Also published as: GB0616388D0; GB2429195B; IES20050547A2; IE20060619A1

Abstract

A tractor drawbar (1) comprises a tow hitch (6) engageable with a connecting member of a trailer drawbar and a latching mechanism (5) co operating with the tow hitch (6) for releasably coupling the tractor and the trailer drawbars together. The latching mechanism (5) has a catch member (7) biased and retained by a spring (14) in a position adjacent the tow hitch (6) when the latter is engaged with the connecting member. The catch member (7) can be deflected away from the tow hitch (6) by overcoming the bias force of the spring (14) in order to engage or disengage the tow hitch (6) and the connecting member. In one embodiment, the tow hitch has a form of a substantially spherical ball receivable in a suitably shaped recess of a hemispherical-shaped connecting member.

Description

A DRAWBAR

The present invention relates to a drawbar and in particular to a drawbar mountable between a tractor and a trailer.

Hydraulic pick up hitches of tractors and similarly powered vehicles are located between the rear wheels of such vehicles on the aft portion of the chassis. The location of the hitch makes it difficult for the vehicle driver to see the hitch, therefore, if the driver wishes to attach an implement, such as a trailer, to the tractor via the hitch the driver must rely on judgement to locate the hitch below a connecting ring of a drawbar of the trailer.

Furthermore, due to the fact that an attached trailer drawbar is attached to the tractor adjacent the body of the tractor, the included angle achievable between the longitudinal axis of the tractor and the longitudinal axis of the towed trailer is limited during turning as the trailer drawbar will abut against a rear wheel of the tractor at a certain included angle.

This is a particular problem when the driver of the vehicle needs to turn the tractor and trailer on a small area of ground.

One solution to the problem of limited included angle between longitudinal axes of tractor and trailer during turning is to provide a bracket extending rearwardly from the chassis of the tractor between the tractors rear wheels. The bracket has a through-bore at or about its free end with a vertical axis. The driver can more readily see the free end of the bracket reducing dependence on judgement to locate the bore of the bracket in alignment with a bore or connecting ring of a trailer drawbar. However, this type of bracket has * * * inherent problems, namely that the driver of the vehicle must firstly set the vertical height of the trailer drawbar to a height approximately corresponding to the height of the rearwardly extending bracket. Once the bore of the bracket and the bore or connecting * * * ring of the trailer drawbar are aligned by the driver of the tractor, the driver must leave the cab of the tractor to insert a connecting pin. Alternatively, another person must step between the tractor and the trailer to insert a connecting pin. This has significant safety risks for the person standing between the tractor and the trailer.

It is an object of the present invention to obviate or mitigate the problems of limited visibility of pick up hitches, the problem of included angle between longitudinal axes of tractor and towed trailer and the problem of unnecessary manual labour and safety risks associated with towing brackets disposed on the aft portion of the chassis of a tractor between the tractor's rear wheels.

Accordingly, the present invention provides a drawbar mountable on, but not limited thereto, a tow arm of a pick-up hitch of a tractor, the drawbar comprising an elongate body having a tractor mountable end and a trailer engageable end, the trailer engageable end having a tow hitch for engaging a connecting member of a trailer drawbar and a latching means mounted on said body, wherein the tow hitch and the latching means cooperate for releasably coupling the trailer and the drawbar together.

Ideally, the latching means is operable between a trailer fastening mode and a trailer release mode.

Ideally, the tow hitch projects proud from an upper, in use, face of said body.

Preferably, the latching means comprise a catch member positionable adjacent the tow hitch in the trailer engaging mode so as to prevent a connecting member of a trailer drawbar from disengaging from the tow hitch. The catch member is also positionable in a position away from the tow hitch to enable release of the connecting member from the tow hitch. S * 5*S

Ideally, the tractor mountable end has means for releasably mounting the drawbar on a tow arm of a pick up hitch of a tractor. * **

S * S * **

* 25 Preferably, the means for releasably fastening the drawbar onto the tractor pick up hitch comprises a plurality of bores formed for receiving the pick up hitch.

* * Preferably, said catch member is movably mounted on the drawbar.

Ideally, the catch member has a free portion and is biased into the trailer engaging position by a biasing means in which position the free portion is adjacent the tow hitch.

Ideally, the catch member is permanently biased into the trailer engaging mode and is movable into the trailer releasing mode by application of a force to the free portion of the catch member adjacent the tow hitch. The catch member is returned into the trailer engaging mode by the biasing means upon withdrawal of the force.

Preferably, the biasing means comprise a spring.

Ideally, the catch member is pivotally mounted about the tow hitch.

In one embodiment, the catch member comprises a body having a first end portion, a second end portion and a heel portion intermediate the first and second end portions, the catch member being pivotally mounted about the tow hitch by the heel portion. . Ideally, the free portion comprises the first portion.

Ideally, the catch member is mounted on a first pivot shaft received in a corresponding bore provided in the heel portion of the catch member with the first end portion facing the trailer engageable end of the drawbar and the second end portion facing the tractor mountable end thereof. The first pivot shaft extends between a pair of first support members spaced apart laterally in relation to a longitudinal axis of the drawbar extending between the trailer engageable end the tractor mountable end.

Preferably, the spring is engaged with one of the support members at one end and with the catch member at the other end. Ideally, the spring is engaged with the catch member at the heel portion thereof and the second end portion abuts the upper face of the drawbar in the trailer engaging mode. * ** * * *5

In use, the catch member is moved into the trailer releasing mode by a connecting * member of a trailer drawbar as the drawbar is being lifted from a lowered position to a * * 5 * raised position so as to enable engagement of the tow hitch and the connecting member in the raised position of the drawbar. Advantageously, upon completion of engagement of the tow hitch with the connecting member, the catch member is returned into the trailer engaging mode by the bias means.

Furthermore, the catch member can be moved into the trailer release mode by pulling a release wire connected about the free portion of catch member thus overcoming the bias force of the spring and moving the free portion away from the tow hitch.

In a further embodiment, the catch member is slidably mounted on the elongate body about the tow hitch. This embodiment is particularly useful when the drawbar is to be mounted on a fixed portion of the chassis of the tractor as opposed to a pick up hitch.

In another embodiment of the drawbar according to the invention, the tow hitch comprises a spherical ball mounted on the upper face of the drawbar at the trailer engageable end thereof.

Advantageously, a hemispherical shaped connecting member'-iiralrailer drawbar, hereinafter referred to as a spoon-shaped connecting member, is provided for mouvitin on a trailer drawbar, an internal surface of the spoon-member being adapted to engage said ball.

Ideally, the spoon-shaped member has a handle portion and a head portion, said head portion comprising a recess for receiving the ball.

Ideally, the recess comprises a first region proximal the opening of the recess and a second region proximal the base of the recess, the first region being substantially cylindrical and the second region being substantially spherical, the spherical region being sized to enable spherical surface contact between the ball of the tow hitch and the walls of spherical region of the recess during when the ball occupies the recess. The provision of a spherical surface contact between the tow hitch and a connecting member of a trailer drawbar helps to reduce wear of both the tow hitch and the connecting member. * * * * **

*? 25 Ideally, the cylindrical region has a diameter which falls within a predetermined range of * * diameters to enable access and accommodation of the ball in the recess. Ideally, the * * * spoon-shaped member is couplable with an existing connecting ring of a trailer drawbar. ** S **

In one embodiment, the latching mechanism comprises a catch member substantially as described above with reference to the preferred embodiment of the drawbar, wherein the catch member is pivotally mounted about the tow hitch by the second end potion.

Preferably, the catch member is mounted on a second pivot shaft received in a matching bore provided in the second end portion of the catch member and the second pivot shaft extends between a pair of second support members spaced apart laterally in relation to the longitudinal axis of the drawbar.

Ideally, the catch member is retained in a trailer engaging mode in which the first end portion is positioned adjacent the tow hitch by a stop shaft receivable in a matching bore provided in the heel portion of the catch member the stop shaft extending between the second support members. The trailer release mode is achieved by withdrawing the stop shaft from its position between the second support members and by pivoting the catch member so as to move the first end portion thereof away form the tow hitch.

In another embodiment, the latching mechanism comprises a removable etaining pin extending above the head portion of the spoon-member when the spoon is engaged with the ball so as to prevent the spoon-member from disengaging from the ball.

Preferably, the retaining pin is supported in its position above the spoon-member by a pair of third support members mounted on the drawbar and spaced apart laterally in relation to the longitudinal axis of the drawbar.

In yet another embodiment, the catch member comprises a plate hingedly connected to the drawbar by a lower portion of said plate. An upper portion of the plate is biased into the trailer engaging mode by the biasing means. In the trailer release mode, the upper portion is moved away from the tow hitch. Ideally, the plate is biased into the trailer engaging mode by a compression spring which is fastened to the plate at one end and to a stationary portion of the drawbar at the other end. *

* *.. Optionally, the plate is hingedly mounted on a platform. Optionally, the spring is fastened to the platform at the other end of the spring. In use, the connecting member and the tow hitch are first aligned at a substantially the same level above the ground. Then, the ** * vehicle together with the drawbar is driven towards the connecting member so that the * ** * connecting member pushes the upper portion of the plate away from the tow hitch to enable engagement of the connecting member and the tow hitch. In addition, the plate is movable into a trailer release mode by pulling a release wire connected to the plate thereby overcoming the bias force of the spring and moving the upper portion of the plate away from the tow hitch.

Optionally, the plate has a substantially Omega(fl)-shaped configuration and is hingedly connected to the platform by the free ends. Preferably, the platform is affixed to a bottom, in use, face of the drawbar and the drawbar is received in the inner space defined by the Omega-shaped body of the plate and the upper surface of the platform.

The invention will now be described with reference to the accompanying drawings, which show by way of example only, five embodiments of a drawbar in accordance with the invention.

In the drawings: Figure 1 is a perspective view of a first embodiment of a drawbar according to the invention; Figure 2 is a side elevation of the drawbar of Figure 1; Figure 3 is a second side elevation of the drawbar of Figure 1; Figure 4 is a third side elevation of the drawbar of Figure 1; Figure 5 is a side elevation of a second embodiment of a drawbar according to the invention; Figure 5a is a side elevation of a spoon of the drawbar of Figure 5; Figure 6 is a perspective view of a third embodiment of a drawbar according to the invention shown mounted on a tow arm of a pick-up hitch mountable on a vehicle and engaged with a spoon attachable to a trailer drawbar; * Figure 7 is a side elevation of the drawbar of Figure 6; Figure 8 is a front elevation of the drawbar of Figure 6; Figure 9 is a perspective view of a spherical ball used in the second, third and * bS * * *. fourth embodiments of the drawbar; Figure 10 is a perspective view of a retaining pin of the third embodiment of the drawbar; es Figure Ills a perspective view of a body of the third embodiment of the drawbar;

IA I

* . Figure 12 is a perspective view showing a fourth embodiment of a drawbar shown mounted on a tow arm of a pick-up hitch mountable on a vehicle, and a spoon attachable to a trailer drawbar; Figure 13 is a side elevation of the drawbar of Figure 12; Figure 14 is a plan view of the drawbar of Figure 12; Figure 15 is a front elevation of the drawbar of Figure 12; and Figure 16 is a perspective view of a latching mechanism of the fourth embodiment of the drawbar.

Referring initially to the Figures 1 to 4 of the drawings there is shown a first embodiment of a drawbar of the invention indicated generally by reference numeral 1. The drawbar 1 has an elongate body 2 with a tractor mountable end 3 and a trailer engagable end 4. A latching mechanism indicated generally by the reference numeral 5 is provided at the trailer engagable end 4. A tow hitch 6 projects proud from an upper longitudinal face 2a of the body 2. The latching mechanism 5 comprises a catch member 7 co-operating with the tow hitch 6 in order to retain a connecting member of a trailer drawbar in engagement with the tow hitch or to release the connecting member therefrom.

The catch member 7 is a substantially L-shaped plate 8 (see especially Figures 2 to 4) having a first end portion 11 and a second end portion 12 and a heel portion 22 and is pivotally mounted between a pair of spaced apart support plates 9 projecting proud from the upper face 2a and extending along the body 2. The catch member 7 is movable between a trailer fastening position in which the first end portion 11 of the catch member 7 is positioned at or near a free end 6a of the tow hitch 6 (see Figure 1 and Figure 2) and a trailer releasing position (see Figure 4) in which the first end portion ills moved away from the free end 6a of the tow hitch 6. The catch member 7 is movable by exertion of a force on any of the heel portion 22, the first portion 11 or the second end portion 12.

The catch member 7 is biased into a trailer fastening position by a compression spring 14 * : : ::* which is connected at one end to the heel portion 22 of the catch member 7 and at the other end to one of the support plates 9. The support plates 9 are mounted on a platform * :*. : 15 which is fastened to a flat surface 16 on the longitudinal face 2a of the elongate body 2 by bolts 17 adjacent the trailer engaging end 4 of the drawbar 1. The plates 9 can be *. : mounted on the drawbar 1 using other suitable known means. As shown in Figures 1 :. and 2, the second end portion 12 abuts a head of a bolt 17 in the trailer fastening position of the latching mechanism 5, but of course it can abut the platform 15, the surface 16 or any other element of the drawbar 1, depending on the configuration of the drawbar 1, in order to prevent upward movement of the first end portion 11 in use.

The elongate body 2 is tubular with a substantially rectangular crosssection but not in any way limited to such a configuration.

A recess 19 is formed at the trailer engaging end 4 of the elongate body 2 in the longitudinal face 2a thereof, and the tow hitch 6 is mounted centrally on the portion of the longitudinal face 2a defining the recess 19. The recess 19 around the tow hitch 6 provides a seat for a connecting ring (not shown) of a trailer drawbar (also not shown).

The tow hitch 6 is fastened to the elongate body 2 in the recess 19 by a bolt 21.

The catch member 7 is pivotally mounted on a pivot pin 41 which extends transversely through the heel portion 22 of the catch member 7. A tongue 23 stands proud of the surface of the catch member 7 defining the heel portion 22. The tongue 23 has an aperture 43 for receiving an end hook 24 of the compression spring 14. End faces 25 of the support plates 9 distal from the tow hitch 6 both have a slot 26 extending into the plate 9 towards the tow hitch 6 for receiving the other end hook 27 of the compression spring 14. The catch member 7 has a release bracket 31 (see Figure 1) mounted on the end portion 12 of the catch member 7. The release bracket 31 has an aperture 34 for receiving a release wire (not shown) which extends from the bracket 3110 an area of the tractor easily accessible to the driver.

The body 2 of the drawbar 1 has a plurality of through-bores 35 extending between the upper longitudinal face 2a and a base longitudinal face opposite the upper face 2a. The through-bores 35 are formed for mounting the drawbar 1 on a tow arm of a pick-up hitch of a tractor or, alternatively, for mounting the drawbar 1 on a fixed portion of the aft S. ..

chassis of a tractor. * ..

* An example of use of the drawbar I will now be described. * * 25

In use, the drawbar 1 is mounted on a movable tow arm of a pick-up hitch of a tractor, ": which may be a hydraulic pick-up hitch mounted on the aft portion of the tractor's chassis.

* S. First, the tractor driver moves the rear of the tractor towards a connecting ring of a trailer drawbar and positions the tow hitch 6 below the connecting ring in register with the connecting ring. Next, the driver actuates the pick-up hitch and the tow arm of the pick- up hitch is lifted from a lowered position into a raised position together with the drawbar 1.

When the trailer engaging end 4 of the drawbar 1 reaches the connecting ring, the catch member 7 abuts the connecting ring during lifting, and the forces acting on the catch member 7 from the connecting ring overcome the biasing force of the compression spring 14 thus causing the catch member 7 to pivot about pivot pin 41. The second end portion 12 is thus lifted and the first end portion 11 is lowered in relation to the base 15 (see Figure 4) and the heel portion 22 pivots towards the tow hitch 6, away from the slots 26, thus extending the compression spring 14. This permits the tow hitch 6 of the drawbar 1 to rise up through the connecting ring until the connecting ring is positioned intermediate the free end 6a and the base of the tow hitch 6. In practice, the tow hitch 6 will rise until the connecting ring is accommodated in the recess 19. Upon positioning in the recess 19, the connecting ring comes out of contact with the catch member 7 thus allowing the spring 14 to compress causing catch member 7 the to pivot about the pivot pin 41 back into the trailer fastening position. Since the first end portion 11 is positioned adjacent the tow hitch 6 in the trailer fastening position, the connecting ring is prevented from disengaging from the tow hitch 6.

In order to release the catch member 7, an operator pulls the release wire so that the catch member 7 pivots about the pivot pin 41, and the end portion 11 is lowered towards the top longitudinal surface 2a of the body 2 away from the tow hitch 6 so as to provide clearance for disengaging the connecting ring from the tow hitch 6. The tow hitch 6 and the first end 11 of the catch member 7 are so arranged in relation to each other that movement of the first end 11, when the tow hitch 6 is engaged with a connecting ring, does not interfere with the connecting ring. The operator then lowers the tow arm of the hydraulic pick-up hitch of the tractor together with the drawbar 1 thus disengaging the tow hitch 6 from the connecting ring of the trailer drawbar. * * S...

* In a modification (not shown in the drawings), a catch member is slidably mounted above, * below or around the tow hitch, and contact between the connecting ring of the trailer *5s * 25 drawbar and the catch member causes the catch member to slide up, down or away from : the tow hitch until the body of the connecting ring has passed under/over or through the :. catch member. The biasing force of the spring then returns the catch member to the * trailer fastening position thereby fastening the trailer and drawbar together.

In Figure 5 there is shown a second embodiment of a drawbar of the invention which has a tow hitch 60 comprising a spherical ball 60a and a base portion 60b. In Figure 5, the features of the drawbar 10 which are the same as those of the drawbar I in Figures 1 to 4 are indicated by the same numerals. The ball 60a is engageable with a recess 82 formed in a head portion 80a of a spoon member 80 attachable to a trailer drawbar. As shown in Figure 5a, the recess 82 comprises a cylindrical region 82a proximal the opening of the recess and a spherical region 82b. The diameter of the cylindrical region 82a falls within a permitted range enabling access and accommodation of the ball in the recess 82. The spherical region 82b is so sized as to enable surface contact between the ball 60a and the walls of the recess defining the spherical region 82b. Such a uball and spoon" engagement between the drawbar 10 and a trailer drawbar provides a longer effective service time of the tow hitch 60 due to the spherical contact between the ball 60a and the walls of the spherical region 82b of the recess 80a as opposed to a "spot" contact between a cylindrical tow hitch and a connecting ring of a trailer drawbar.

The ball 60 has a threaded shank 61 and is secured onto the elongate body 2 with a nut 22. The spoon 80 comprises a handle portion 80b by which the spoon is affixed to a trailer drawbar.

The drawbar 10 comprises a catch member 70 having a first end portion 110, a second end portion 120 and a heel portion 220 intermediate the end portions. The catch member is pivotable about a shaft 410 which extends between the side plates 9 (only one side plate 9 can be seen in Figure 5) through the body of the catch member 70 at the second end portion 120. The catch member 70 is pivotable about the shaft 410 between a trailer engaging position in which the first end portion 110 is located adjacent the ball 60a, and a trailer release position in which the first end portion 110 is moved away from the ball 60a.

A through-bore (not indicated by a numeral) is formed in the body of the catch member 70 * at the heel portion 220 thereof and extends parallel to the shaft 410. The through bore is :* : :* adapted for receiving a stop shaft 420. ***

In use, the tractor driver moves the rear of the tractor towards the spoon member 80 mounted on a trailer drawbar and positions the ball 60a of the tow hitch 60 below the * spoon 80 in register with the recess 82. Next, the driver actuates the pick-up hitch and * the tow arm of the pick-up hitch is lifted from a lowered position into a raised position together with the drawbar 10 until the ball 60a engages in the recess 82 of the spoon 80.

The catch member is then pivoted about the shaft 410 into the trailer engaging position.

The stop shaft 420 is then threaded through the bore at the heel portion 220 of the catch member 70 and through corresponding apertures (not shown) in the side plates 9. The stop shaft 420 is fastened in position with a catch pin 45 received in a matching transverse bore (not shown) of the stop shaft 420. The stop shaft 420 prevents the catch member 70 from pivoting about the shaft 410 and thus the first end portion 110 retains the spoon 80 in engagement with the tow hitch 60.

A grease supply channel 38 is provided in the head portion 80a of the spoon 80 for supply of grease between the outer surface of the ball 60a and the walls of the recess 82.

Preferably, the recess 82 of the head portion BOa of the spoon member 80 is sized to accommodate about Iwo thirds of the diameter of the ball 60a.

Figures 6 to 11 show a third embodiment of a drawbar indicated generally by reference numeral 20. The drawbar 20 is shown mounted on a movable tow arm 251 of a known tractor pick-up hitch 250. The tow arm is pivotable relative an upper fixed part 253 about a pivot 252. In Figures 6 to 11, the features of the drawbar 20 which are the same as those of the above described drawbar 10 are indicated by the same numerals. The drawbar 20 comprises an elongate body 26 which is similar to the elongate body 2 described above but has only one through bore 35 (see Figure 11) for mounting on a tow arm of a pick-up hitch. Only the trailer engageable end 4 of the body 26 can be seen in Figures6to 11.

Like the drawbar 10, the drawbar 20 comprises a tow hitch 60 engageable with a spoon 80 of a trailer drawbar. The procedure of locating the ball 60a in the recess 80a of the S.. spoon 80 mounted on a trailer drawbar is the same as described for the drawbar 10 S...

above. * *5

In use, the spoon 80 is retained in an engagement with the tow hitch 60 by a retaining pin 75. The retaining pin 75 extends between a pair of support plates 90 above the spoon 80 in a trailer fastening position. The retaining pin 75 is removably received in corresponding apertures 93 (see Figure 10) in the plates 90. The plates 90 are mounted * 5: on a platform 92 one at each longitudinal side of the body 26 so that the tow hitch 60 is positioned intermediate the plates 90. The platform 92 has a through aperture 94 (see Figure 10) for fastening the platform 92 to a base longitudinal face of the body 26 by threading the shank 61 of the tow hitch 60 through the aperture and tightening a nut 22.

In the trailer fastening position, the retaining pin 75 is secured in the apertures 93 in the plates 90 above the tow hitch 60 by a catch pin 71 threaded transversely through a matching channel (not indicated by a reference numeral) in the retaining pin 75.

In order to release the spoon 80, the retaining pin 75 is disengaged from the support plates 90 by releasing the catch pin 71 and withdrawing the retaining pin 75 from the corresponding apertures 93 in the side plates 90. An operator then lowers the tow arm 251 of the pick-up hitch 250 together with the drawbar 2 thus disengaging the tow hitch 60 from the spoon member 80.

Figures 12 to 16 show a fifth embodiment of a drawbar indicated generally by reference numeral 200. Like the described above drawbar 20, the drawbar 200 is shown mounted on a movable tow arm 251 of a known tractor pick-up hitch 250 and is engageable with a spoon 85 mountable to a trailer drawbar. In Figures 12 to 16, the features of the drawbar which are the same as those of the described above drawbar 20 are indicated by the same numerals.

A spoon 85 differs from the spoon 80 in that it has a handle portion 85a with an expanded end portion 85c for fastening the spoon 85 to a trailer drawbar.

The drawbar 200 differs from the drawbar 20 in that it has a latching mechanism 700 for retaining the spoon 85 in an engagement with the tow hitch 60. The latching mechanism * 20 700 (see also Figure 16) comprises a base platform 710 having a through aperture 710a for fastening to the base longitudinal face of the body 26 of the drawbar 200 in the same S...

S.... * manner as described above with reference to the platform 92 of the drawbar 20. The * ,* latching mechanism 700 further comprises a catch member in a form of a substantially * : Omega(fl).shapeci plate 720 hingedly connected at its free ends to a rear face 71 Ob of the * 25 base platform 710 via a shaft 730. The Omega-shaped plate 720 is pivotable about the ". : shaft 730 between a trailer fastening position, in which the apex portion 720a of the plate 720 is positioned adjacent the tow hitch 60, and a trailer release position in which the * apex portion 720a is moved away from the tow hitch 60. In use, the Omega-shaped plate 720 has a front face 721 facing the tow hitch 60 and a rear face 722 facing the tractor mountable end of the drawbar 200.

The Omega-shaped plate 720 is biased into the trailer fastening positionby a compression spring 740. The spring 740 is hooked at its one end to a first finger 741 affixed to the base platform 710 and at its other end to a second finger 742 affixed to the rear face 722 of the Omega-shaped plate 720. A stop 750 is provided at one of the free ends of the Omega- shaped plate 720 for preventing the plate from being over-biased by the spring 740.

A tongue 760 projects proud from the front face 721 of Omega-shaped plate 720, about the apex portion 720a of the plate. The tongue 760 prevents the spoon 80 from disengaging form the ball 60a in the trailer fastening position of the latching mechanism.

The tongue has a lug 770 with an eyelet 771 for receiving a release wire (not shown) which extends from the lug 770 to an area of the tractor easily accessible to the driver.

In use, the spoon 85 and the tow hitch 60 are positioned at substantially the same level above the ground. Next, the tractor is driven towards the trailer thus causing the spoon to push the Omega-shaped plate 720 away from the tow hitch 60 and extend the spring 740.

Next, the tow hitch 60 engages the spoon 85. Upon positioning of the ball 60a in the recess (not shown) of the spoon 85, the spoon 85 disengages from the Omega-shaped plate 720. Next, the spring 740 compresses bringing the Omega-shaped plate into the trailer fastening position (see Figure 13) .

In addition, the tractor driver may pull the release wire so that the Omega-shaped plate 720 pivots about the shaft 730 and moves away from the ball 60a thus enabling release of : 20 the spoon 85.

* In order to release the spoon 85 the driver pulls the release wire again to move the * ** Omega-shaped plate 720 away from the tow hitch 60 so as to provide clearance for disengaging the spoon 85 from the tow hitch 60. The tow arm 251 can then be lowered *** * 25 in order to release the trailer drawbar. ** * * S S

:5 It will or course be understood that the present invention is not limited to the specific *, .: details herein described which are given by way of example only, and that various alternations and modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS: 1. A drawbar comprising an elongate body having a tractor

mountable end and a trailer engageable end, the trailer engageable end having a tow hitch for engaging a connecting member of a trailer drawbar, and a latching means mounted on the body, wherein the tow hitch and the latching means co-operate for releasably coupling the trailer and the drawbar together, the latching means being operable between a trailer engaging mode and a trailer release mode.
2. A drawbar as claimed in Claim 1, wherein the latching means comprises a catch member positionable adjacent the tow hitch in the trailer engaging mode so as to prevent a connecting member of a trailer drawbar from disengaging from the tow hitch.
3. A drawbar as claimed in Claim 1 or Claim 2, wherein the tow hitch projects proud from an upwardly facing surface of the body.
4. A drawbar as claimed in any preceding claim, wherein the catch member is movably mounted on the drawbar and is movable between a position adjacent the tow hitch in the trailer engaging mode, and a position away from the tow hitch to enable : * 20 release of the connecting member from the tow hitch. ****
5. A drawbar as claimed in Claim 4, wherein the catch member has a free portion and is biased into the trailer engaging position by a biasing means in which position the * free end is adjacent the tow hitch.

*. :
6. A drawbar as claimed in Claim 5, wherein the basing means is operable to bias the *:.* catch member permanently into the trailer engaging mode, the catch member being movable into the trailer release mode by application of a force to the free portion of the catch member adjacent the tow hitch so as to overcome the bias force of the biasing means, the biasing means being further operable to return the catch member into the trailer engaging mode upon withdrawal of the force.
7. A drawbar as claimed in Claim 5 or Claim 6, wherein, a release wire is connected top the catch member about the free portion thereof so that the catch member can be moved into the trailer release mode by pulling the release wire and overcoming the bias force thereby moving the free portion of the catch member away from the tow hitch.
8. A drawbar as claimed in any of Claims 5 to 7, wherein, the biasing means comprise a spring.
9. A drawbar as claimed in any preceding claim, wherein the catch member is pivotally mounted about the tow hitch.
10. A drawbar as claimed in Claim 9, wherein the catch member comprises a body having a first end portion, a second end portion and a heel portion intermediate the first and second end portions, the catch member being pivotally mounted about the tow hitch by the heel portion, and wherein the first portion comprises the free portion.
11. A drawbar as claimed in Claim 10, wherein the catch member is mounted on a first pivot shaft received in a corresponding bore provided in the heel portion of the catch member with the first end portion facing the trailer engageable end of the drawbar and the second end portion facing the tractor mountable end thereof, the first pivot shaft extending between a pair of first support members spaced apart laterally in relation to a longitudinal : * 20 axis of the drawbar extending between the trailer engageable end the tractor mountable end. S... * . **

*:::*
12. A drawbar as claimed in Claim 11, wherein the spring is engaged with one of the * first support members by one end of the spring, and with the catch member at the heel *..

portion thereof by the other end of the spring, so that in the trailer engaging mode the second end portion abuts the upwardly facing surface of the drawbar. * S S * S.
13. A drawbar as claimed in Claim 12, wherein in use the catch member is biased into the trailer release mode by a connecting member of a trailer drawbar as the drawbar is being lifted from a lowered position to a raised position thereby enabling engagement of the tow hitch and the connecting member in the raised position of the drawbar, the spring being operable to return the catch member into the trailer engaging mode upon completion of engagement of the tow hitch with the connecting member.
14. A drawbar as claimed in any of Claims 1 to 9, wherein the tow hitch comprises a substantially spherical ball mounted on the upwardly facing surface of the drawbar at the trailer engageable end thereof for cooperation with a spoon-shaped connecting member of a trailer drawbar.
15. A drawbar as claimed in Claim 14, wherein the catch member is pivotally mounted on a second pivot shaft, the second pivot shaft being received in a matching bore provided in the second end portion of the catch member and the second pivot shaft extending between a pair of second support members spaced apart laterally in relation to the longitudinal axis of the drawbar.
16. A drawbar as claimed in Claim 15, wherein a stop shaft is provided for retaining the catch member in the trailer engaging mode, the stop shaft being receivable in a matching bore provided in the heel portion of the catch member and the stop shaft extending between the second support members, and wherein the trailer release mode is achieved by removing the stop shaft from its position between the second support members and by pivoting the catch member so as to move the first end portion thereof away form the tow hitch.

* *, 20
17. A drawbar as claimed in Claim 14, wherein the catch member comprises a plate having an upper free portion and a lower portion, the lower portion being hingedly * * connected to the drawbar, the upper free portion being biased into the trailer engaging * * : :* mode by the biasing means, and the upper free portion being movable away from the tow * hitch into the trailer release mode.
18. A drawbar as claimed in Claim 17, wherein the plate has a substantially omega(Q)- * : .* : shaped configuration and has a pair of free ends at the lower portion of the plate, the plate being hingedly connected to the drawbar by the free ends.
19. A drawbar as claimed in Claim 18, wherein the free ends of the omega(fl)-shaped plate are attached to an upwardly facing surface of a platform affixed to a downwardly facing face of the drawbar so that the drawbar is received in an inner space defined by the omega(Q)-shaped body of the plate and the upper surface of the platform.
20. A drawbar as claimed in Claim 19, wherein the spring is fastened to the plate by one end and to a stationary portion of the drawbar by the other end, so that in use, the upper free portion of the plate can be pushed by a connecting member of a trailer drawbar away from the tow hitch to enable engagement of the connecting member and the tow hitch.
21. A drawbar as claimed in any of Claims 1 to 8, wherein, the catch member is slidably mounted on the elongate body of the drawbar about the tow hitch.
22. A drawbar as claimed in any preceding claim, wherein the tractor mountable end has means for releasably mounting the drawbar on a tow arm of a pick up hitch of a tractor.
23. A drawbar comprising an elongate body having a tractor mountable end and a trailer engageable end, the trailer engageable end having a tow hitch for engaging a connecting member of a trailer drawbar, and a latching means mounted on the body, wherein the tow hitch and the latching means co-operate for releasably coupling the trailer and the drawbar together, the latching means being operable between a trailer engaging mode and a trailer release mode, wherein the tow hitch comprises a substantially * ** 20 spherical ball mounted on the upwardly facing surface of the drawbar at the trailer : :: engageable end thereof for cooperation with a spoon-shaped connecting member of a trailer drawbar * *s * * * * :
24. A drawbar as claimed in Claim 23, wherein the latching mechanism comprises a removable retaining pin extending above the tow hitch in the trailer engaging mode. * * * * S
25. A drawbar as claimed in Claim 24, wherein the retaining pin is supported in its position by a pair of third support members mounted on the drawbar and spaced apart laterally in relation to the longitudinal axis of the drawbar.
26. A connecting member of a trailer drawbar for engagement with a tow hitch of a tractor drawbar, the connector having a spoon-shaped configuration and being adapted to engage with a substantially spherical ball-shaped tow hitch mounted on an upwardly facing surface of a tractor drawbar.
27. A connecting member as claimed in Claim 26, comprising a handle portion and a head portion, the head portion comprising a recess sized and shaped for receiving the ball of the tow-hitch.
28. A connecting member as claimed in Claim 27, wherein the recess is defined by a wall having a first region proximal an opening of the recess and a second region proximal a base of the recess, the first region being substantially cylindrical and the second region being substantially spherical, the spherical region being sized to enable spherical surface contact between the ball of the tow hitch and the first region of the wall defining the recess when the ball occupies the recess thereby reducing wear of both the tow hitch and the connecting member.
29. A connecting member as claimed in Claim 28, wherein the cylindrical region has a diameter which falls within a predetermined range of diameters to enable access and accommodation of the ball in the recess.
30. A connecting member as claimed in any of Claims 26 to 29, wherein the connecting member is couplable with an existing connecting ring of a trailer drawbar.

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31. A drawbar substantially in accordance with any of the embodiments substantially as hereinbefore described with reference to, and as shown in the accompanying drawings * a I * :
32. A connecting member of a trailer drawbar for engagement with a tow hitch of a a..

tractor drawbar substantially as herein described with reference to, and as shown in Figures 5 to 14 of the accompanying drawings. a S. * ,.