GB2625342A

GB2625342A - A coupling

Info

Publication number: GB2625342A
Application number: GB2218875.9A
Authority: GB
Inventors: Mary Reilly Felix; Vilemas Klemensas
Original assignee: Securi Cabin Ltd
Current assignee: Securi Cabin Ltd
Priority date: 2022-12-14
Filing date: 2022-12-14
Publication date: 2024-06-19
Also published as: GB202218875D0

Abstract

A coupling 10 is provided for connecting a trailer 20 to a towing vehicle and comprises a support frame 30 mountable on a trailer 20, a drawbar 50 extendable forwardly from the support frame 30 in a towing position. The coupling 30 comprises an elongate guide track 90 on the support frame 30 to guide the drawbar 50 between the towing position and a retracted position in which the drawbar is oriented generally transversely to the towing position. The drawbar 50 is secured to a pivot shaft 170 via a sleeve 51 configured to rotate about the pivot shaft 170. A guide roller 150 and an anti-rotation lock (210 fig 2) are also typical. The invention may be for a mobile toilet unit and provides a reduced footprint when the drawbar is stored.

Description

A COUPLING

Field of Invention

This invention relates to a coupling with a retractable drawbar for connecting a trailer/drawn vehicle to a towing vehicle.

Background of the Invention

Couplings are widely used to connect trailers, vehicles, mobile accommodation units (caravans, mobile office units, mobile toilets and the like), hereinafter referred to collectively as trailers, to a towing vehicle. In general, known couplings are made up of a support frame attached to the trailer and an elongate drawbar extending from the support frame which is attached to the towing vehicle at the vehicle towbar. However, when the towing vehicle is disconnected from the trailer, the drawbar in general continues to project from the trailer and can form an obstruction or safety hazard. This is particularly the case with mobile accommodation units such as mobile toilets and the like which can be deployed in busy environments such as concerts, building sites and the like. In addition, the elongate drawbar significantly increases the footprint of the trailer which can be problematical where space is at a premium and also increases the space required, both indoors and outdoors, to store the trailer when not in use.

An object of the invention is to overcome at least some of the problems of the prior art.

Summary of the Invention

According to the invention there is provided a coupling for connecting a trailer to a towing vehicle wherein the coupling comprises: a support frame mountable on a trailer; a drawbar extendable forwardly from the support frame in a first towing position and having a trailer end and a free end; an elongate guide track on the support frame configured to guide the drawbar between the first towing position and a second retracted position in which the drawbar is oriented generally transversely to the first towing position.

In one embodiment, the drawbar is movable between the first towing position and the second retracted position about a pivot axis between the trailer end and the free end of the drawbar.

In any embodiment, the pivot axis is substantially midway between the trailer end and 10 the free end of the drawbar.

In any embodiment, the pivot axis is positioned to the side of the drawbar.

In any embodiment, the pivot axis is defined by a vertical pivot shaft on the support 15 frame.

In any embodiment, the drawbar is secured to the pivot shaft via a sleeve configured to rotate about the pivot shaft.

In any embodiment, the guide track comprises an elongate trackway shaped to have a generally straight portion extending from the trailer end of the drawbar and a curved end portion.

In any embodiment, the guide track comprises a channel for guiding the drawbar between the towing and retracted positions.

In any embodiment, the drawbar comprises a guide engageable with the guide track.

In any embodiment, the guide comprises a guide roller.

In any embodiment, the coupling further comprises a releasable locking mechanism to secure the drawbar in the towing position and release the drawbar for movement into the retracted position.

In any embodiment, the locking mechanism comprises an anti-rotation front lock for preventing rotation of the drawbar about the pivot axis.

In any embodiment, the anti-rotation front lock comprises a locking pin insertable in and removable from a complementary locking pin hole on the rotatable sleeve.

In any embodiment, the locking mechanism comprises a rear catch lock configured to prevent release of a catch on the trailer end of the drawbar.

In any embodiment, the rear catch lock comprises a locking bolt insertable in and removable from a complementary barrel.

In any embodiment, the coupling further comprises a trailer handbrake activation 15 mechanism.

In another embodiment, the extension extends to a trailer comprising a coupling as hereinbefore defined In one embodiment, the trailer is a mobile toilet unit.

The coupling of the invention facilitates the storage of a drawbar in a widthwise manner across a trailer or other vehicle without requiring the shortening of the drawbar i.e. the drawbar can therefore be stored across the full width of a trailer in its complete full length state. The stored drawbar does not obstruct passers-by whilst also minimising the footprint of vehicles fitted with the coupling of the invention when parked or being stored. Due to the use of a centrally positioned pivot axis and a guide track, the drawbar can be moved from the towing position to the retracted storage position in one easy fluid movement without requiring tools and the like. Accordingly, as the pivot axis is not located at the drawbar/trailer junction, stresses are significantly reduced at the trailer/drawbar junction thus resulting in a significant decrease in wear and tear with the coupling of the invention over time.

Brief Description of the Drawincis

The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view from above and one side of a first embodiment of a coupling of the invention fitted to a trailer in which the coupling is made up of a retractable drawbar slidable along a guide track in a support frame in which the retractable drawbar is in a first extended locked towing position, a guide roller for guiding the drawbar along the guide track is in a locked position; Figure 2 is a perspective view from above and one side of the coupling of Figure 1 with the retractable drawbar in an intermediate unlocked partially retracted position between the first locked towing position and a second retracted or stored position and with the guide roller in an unlocked rolling position in the guide track; Figure 3 is a top plan view of the coupling of Figure 2; Figure 4 is top plan view of the coupling of Figure 3 with the retractable drawbar stored in the retracted stored position so that the longitudinal axis of the stored drawbar is generally transverse to the longitudinal axis of the extended unstored drawbar in the towing position i.e. the retractable drawbar is stored widthwise across the trailer; Figure 5 is a perspective view from above and one side of the coupling of Figure Figure 6 is an image of a trailer in the form of a mobile toilet fitted with the coupling of Figures 1 to 5 with the retractable drawbar in the extended towing position; Figure 7 is an image of the mobile toilet of Figure 6 with the mobile toilet in a lowered operating position and the drawbar in the second retracted or stored position widthwise across the trailer, and Figure 8 is an image of the mobile toilet of Figure 7 with a slidable cover placed over the retracted drawbar to conceal the retracted drawbar and support frame.

Detailed Description of the Invention

Figures 1 to 5 show a coupling 10 of the invention in a first towing position mounted on a trailer 20 for connecting the trailer 20 to a towing vehicle (not shown). In the present embodiment, the trailer 20 is a mobile toilet unit. However, as will be appreciated by those skilled in the art, the invention is not limited to such trailers 20 which can take many forms including trailers for boats etc, horse boxes, vehicles, mobile accommodation units, mobile office units and the like. As shown in the drawings, the coupling 10 is made up of a support frame 30 having a transverse mounting bar 31 extending the widthwise across the trailer chassis 40. A drawbar 50 extends forwards from the transverse mounting bar 31 towards the towing vehicle and has a free end 60 provided with a vehicle coupling head 70 for attachment to a vehicle towbar and an opposite trailer end 80 at the support frame 30. The support frame 30 is provided with an elongate guide track 90 for receiving the drawbar 50 in a retracted position. As shall be explained more fully below, the drawbar 50 is movable between the first towing and the second retracted positions along the guide track 90 to transversely store the drawbar 50 across the trailer 20 when not required e.g. when the trailer 20 is in a desired fixed location.

The guide track 90 is generally disposed in a widthwise direction across the trailer chassis 40 i.e. has a longitudinal axis disposed generally transverse to the longitudinal axis of the drawbar 50 in the towing position so that the drawbar 50 can be stored in a space saving generally widthwise direction on the trailer chassis 40 in the retracted position. In the present embodiment, the guide track 90 is made up of a lower trackway 100 formed by a channel 110 for guiding the drawbar 50 in which the trailer end 80 of the drawbar 50 is slidable between the towing and retracted positions. The trackway 100 is longitudinally shaped to have a generally straight portion 120 extending from the trailer end 80 of the drawbar 50 to a curved end portion or bend 130 of the trackway 100 so that the free end 60 of the drawbar 50 can be almost fully recessed beneath the trailer chassis 40 in the fully retracted position shown in Figure 5.

The drawbar 50 is provided with a guide 140 at its trailer end 80 which is slidable in the channel 110 between the towing and sliding positions to guide the drawbar 50 securely along the channel 110. In the present embodiment, the guide 140 is a guide roller 150 mounted at the trailer end 80 of the drawbar 50.

The drawbar 50 is rotatable about a pivot axis 160 defined on the coupling 10 by a vertical pivot shaft 170 disposed perpendicular with respect to the drawbar longitudinal axis. The pivot shaft 170 is positioned adjacent but to the side of the drawbar 50 approximately midway between the drawbar free end 60 and trailer end 80. More particularly, the pivot shaft 170 is pivotably mounted between pivot shaft mounting plates 180,181 secured to the mounting bar 31 which is in turn secured to the trailer chassis 40 as outlined above. The drawbar 50 is slidably supported on the coupling 10 adjacent the pivot shaft 170 in a sleeve 51 which is secured to the pivot shaft 170 so that the sleeve 51 and hence the drawbar 50 can rotate about the pivot axis 160.

Accordingly, the drawbar 50 is simultaneously slidable in the sleeve 51 and rotatable about the pivot axis 160 in a single motion to move the drawbar 50 between the towing and retracted positions.

At its trailer end 80, the drawbar 50 is further provided with a trailer end catch 225 to securely attach the coupling 10 to the trailer 20 so that the drawbar 50 draws the trailer 20 in the towing position. More particularly, the trailer end catch 225 is made up of a hook 226 at the drawbar trailer end 80 and a complementary fixed bar 227 engageable with the hook 226 in the towing position.

The coupling 10 of the invention is also provided with a releasable locking mechanism 200 to secure the drawbar 50 in the towing position and release the drawbar for movement into the retracted storage position. As shown in Figure 1, the locking mechanism 200 is made up of an anti-rotation front lock 210 for preventing rotation of the drawbar 50 about the pivot shaft 170 and a rear catch lock 230 for preventing release of the trailer end catch 225. More particularly, the front lock 210 is located at the pivot shaft 170 and is made up of a biased vertically disposed front locking pin 211 at a bracket plate 190 defined by an upper wall of the sleeve 51. The front locking pin 211 is provided with a spring to be biased into a complementary locking pin hole 212 defined in the top bracket plate 190. A front lock handle 213 extends from the front locking pin 211 to release the locking pin 211 from the pin hole 212 and allow rotation of the drawbar about the pivot shaft 170.

The rear catch lock 230 is made up of a sprung horizontally disposed locking bolt 231 which is insertable in and removable from a complementary barrel 232 provided on the chassis 40. The locking bolt 231 and complementary barrel 232 are positioned immediately adjacent the trailer end catch 225 to prevent the drawbar 50 from detaching from the trailer 20 in the towing position. The locking bolt 231 is movable between a locked position, in which the hook 226 is prevented from disengaging from the fixed bar 227, and an unlocked position, in which the hook 226 can be detached from the fixed bar 227 by rotating the drawbar 50 about the pivot shaft 170, by a lock cable 233 which extends from the rear catch lock 230 to a manually operable unlocking handle 234 disposed towards the drawbar free end 80.

A trailer handbrake activation mechanism 240 is provided on the coupling 10 and is made up of a handbrake cable 241 which extends beneath the drawbar 50 from a handbrake grip 250 to activate and deactivate the trailer handbrakes as required.

In use, the drawbar 50 of the coupling 109 can be moved between the towing position shown in Figure 1, in which the drawbar 50 is securely locked into the towing position and prevented from rotating and retracting by the anti-rotation front lock 210 and rear catch lock 230 of the locking mechanism 200, and the retracted position shown in Figure 5 by releasing the front lock 210 and rear catch lock 230 as follows. Firstly, the front lock handle 213 is gripped by the user and raised to lift the front locking pin 211 from the locking pin hole 212 so that the drawbar 50 is free to rotate about the pivot shaft 170 in the sleeve 51. The front locking pin 211 can be maintained in the raised position by a lug (not shown) on the bracket plate 190. The locking bolt 231 of the rear catch lock 230 is then released from its barrel 232 by operating the unlocking handle 234. The hook 226 of the trailer end catch 225 is then free to detach from the fixed bar 227 and the trailer drawbar 50 is then free to be rotated in a clockwise manner about the pivot shaft 170 (see Figures 2 and 3) in the sleeve 51.

The guide roller 150 at the trailer end of the drawbar 50 is therefore free to travel in the channel 110 to the end of the bend 130 in the channel 110 so that the drawbar is fully retracted into the trailer 20 in a widthwise manner across the trailer 20 (i.e. is disposed generally transverse to the longitudinal axis of the drawbar 50 when in the towing position (see Figures 4 and 5)). The drawbar 50 is therefore fully stowed without a requiring a reduction in length of the drawbar 50. In addition, the trailer handbrake can remain in the on position when the trailer 20 is parked i.e. movement of the drawbar 50 between the towing and retracted positions does not interfere with the operation of the handbrake cable 240.

In order to return the drawbar 50 to the towing position, the sequence is reversed.

Figures 6 to 8 show images of a trailer 20 in the form of a mobile toilet 260 fitted with the coupling 10 of Figures 1 to 5. More particularly, Figure 6 shows the mobile toilet 260 with the retractable drawbar 50 in the extended towing position projecting forwards from the chassis 40 of the mobile toilet 260 while Figure 7 shows the mobile toilet 260 in a lowered operating position on the chassis 40 and the drawbar 50 in the second retracted or stored position corresponding with Figure 5. Figure 8 shows the mobile toilet 260 with a slidable cover placed over the retracted drawbar 50 to conceal the coupling 10. The concealed coupling 10 does not therefore present any obstacle to passers-by when parked.

The coupling of the invention can be formed from any suitable materials such as square steel hollow section.

Claims

Claims 1 A coupling (10) for connecting a trailer (20) to a towing vehicle wherein the coupling (10) comprises: a support frame (30) mountable on a trailer (20); a drawbar (50) extendable forwardly from the support frame (30) in a first towing position and having a trailer end (80) and a free end (60); an elongate guide track (90) on the support frame (30) configured to guide the drawbar (50) between the first towing position and a second retracted position in which the drawbar (50) is oriented generally transversely to the first towing position.
2 A coupling (10) as claimed in Claim 1 wherein the drawbar (50) is movable between the first towing position and the second retracted position about a pivot axis (160) between the trailer end (80) and the free end (60) of the drawbar (50).
3 A coupling (10) as claimed in Claim 2 wherein the pivot axis (160) is substantially midway between the trailer end (80) and the free end (60) of the drawbar (50).
4. A coupling (10) as claimed in Claim 3 wherein the pivot axis (160) is positioned to the side of the drawbar (50).
5. A coupling (10) as claimed in any of Claims 2 to 4 wherein the pivot axis (160) is defined by a vertical pivot shaft (170) on a rotatable sleeve (30).
6. A coupling (10) as claimed in Claim 5 wherein the drawbar (50) is secured to the pivot shaft (170) via a sleeve (51) configured to rotate about the pivot shaft (170).
7. A coupling (10) as claimed in any of Claims 1 to 6 wherein the guide track (90) comprises an elongate trackway (100) shaped to have a generally straight portion (120) extending from the trailer end (80) of the drawbar (50) and a curved end portion (130).
8 A coupling (10) as claimed in Claim 7 wherein the guide track (90) comprises a channel (110) for guiding the drawbar (50) between the towing and retracted positions
9. A coupling (10) as claimed in any of Claims 1 to 8 wherein the drawbar (50) comprises a guide (140) engageable with the guide track (90).
10. A coupling (10) as claimed in Claim 9 wherein the guide (140) comprises a guide roller (150).
11. A coupling (10) as claimed in any of Claims 2 to 10 further comprising a releasable locking mechanism (200) to secure the drawbar (50) in the towing position and release the drawbar (50) for movement into the retracted position.
12. A coupling (10) as claimed in Claim 11 wherein the locking mechanism (200) comprises an anti-rotation front lock (210) for preventing rotation of the drawbar (50) about the pivot axis (160).
13. A coupling (10) as claimed in Claim 12 wherein the anti-rotation front lock (210) comprises a locking pin (211) insertable in and removable from a complementary locking pin hole (212) on the support frame (30).
14. A coupling (10) as claimed in any of Claims 11 to 13 wherein the locking mechanism (200) comprises a rear catch lock (230) configured to prevent release of a catch (225) on the trailer end (80) of the drawbar.
15. A coupling (10) as claimed in Claim 14 wherein the rear catch lock (230) comprises a locking bolt (231) insertable in and removable from a complementary barrel (232).
16. A coupling (10) as claimed in any of Claims 1 to 15 further comprising a trailer handbrake activation mechanism (240).
17. A trailer (20) comprising a coupling (10) as claimed in any of Claims 1 to 16.
18. A trailer (20) as claimed in Claim 17 which is a mobile toilet unit.