GB2164991A

GB2164991A - Coupling

Info

Publication number: GB2164991A
Application number: GB08432765A
Authority: GB
Inventors: Terry Nangle; John Nangle; Salih Kazim
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-12-29
Filing date: 1984-12-29
Publication date: 1986-04-03
Also published as: GB2164991B; GB8432765D0; SG66887G

Abstract

A coupling comprises a slotted member (12) and a key member (22), wherein the key member is arranged to be inserted into the slot (14) of the slotted member and to be latched to the slotted member upon being partially rotated. The coupling is particularly envisaged for use as a secondary safety coupling between a towing vehicle and a trailer which are coupled by a primary coupling such as a ball and socket coupling. A gate fastening (fig. 5) is also disclosed. <IMAGE>

Description

SPECIFICATION Coupling The invention relates to couplings.

When trailers such as boat trailers or caravans are towed by a vehicle, the primary coupling is between a tow bar and socket mounted on the trailer and a ball mounted on the towing vehicle. However, there are often provided in addition safety chains which are mounted on the trailer. The safety chains are connected to the towing vehicle at a point adjacent the towing ball by means of shackles.

The use of shackles to connect the safety chain can be highly inconvenient. For example, the shackles include threaded connections which can become rusted in use and it is very time consuming to fasten and undo the threaded connections. Also, the nuts of the threaded connections are easily lost.

The present invention provides a coupling for a chain which is easier to use than shackles whilst providing an efficient couple.

In accordance with the present invention there is provided a coupling which comprises a slotted member and a key member, wherein the key member is arranged to be inserted into the slot of the slotted member and to be latched in the slotted member upon being partially rotated. The slotted member is typically arranged to be affixed to a towing vehicle or a stationary article while the key member is typically arranged to be affixed to a chain or other non-rigid connecting means.

The present invention will be described with particular reference to safety chains for use with trailers coupled to a towing vehicle but it should be appreciated that it is of general applicability. For example, it could be used in relation to a gate to provide a means for ensuring that the gate remained closed. Also, the slotted member could be built into the front of a boat and the key member inserted into the slotted member. The key member would be attached to a chain mounted on a winch so that the coupling member could be used to winch the boat onto a trailer. Preferably, the slotted member wouid be rounded to form a horseshoe or half-moon shape for safety reasons.

Typically, a trailer comprises a pair of lengths of chain extending from its forward end. In the present invention, a key member is affixed to the free end of each length of chain. Preferably, each key member is flat and may be stamped out of metal. Each key member may comprise a wide body portion at a first end, an intermediate narrow neck portion and a wide bar portion generally at right angles to the neck portion at a second end.

Conveniently, the key member is affixed at its first end to the free end of a length of chain by welding.

Preferably, the body portion of the key member is shaped to conform with the shape of the end link of the length of chain to provide a strong weld joint.

The slotted member is preferably affixed to the towing vehicle and is preferably flat and may be stamped out of metal. The slot in the slotted member is elongated to enable the bar portion of the key member to be passed through it. Further, the slot is preferably arranged to be substantially vertical in use. Still further, the slot preferably contains an enlarged portion. The enlarged portion is so dimensioned as to enable the neck portion to be rotated within the slot after the bar portion has been passed through the slot. The remainder of the slot is preferably so dimensioned as to prevent rotation of the neck portion within it.

In use, a trailer typically has two chains with respective free ends or a single length of chain with two free ends. In either case, a similar key member is preferably affixed to each end as described above.

To affix the chains to the towing vehicle the key members are engaged with the slotted member by inserting each bar memberth rough the slot so that the neck portion is within the slot, and then partially rotating the neck member, for example through 90 , within the slot so as to cause the bar member to engage behind the slotted member.

As described above, the slot is preferably vertical in use, so that the two key members normally rest one above the other in the bottom of the slot.

Therefore, one bar portion may be shorter than the other bar portion. In use, the shorter bar portion key member is preferably disposed below the longer bar portion key member in the slot.

Further, the length of the slot is preferably such that only the shorter bar portion can be rotated and removed through the slot when the two key members are engaged with the slotted member.

Thus, the larger bar portion cannot be removed when the shorter bar portion is in its engaged position. When the longer bar portion is overlying the shorter bar portion it tends to hold the shorter bar portion down and prevent it being inadvertently rotated and disengaged. This is an added safety factor and has the advantage of making it difficult for children to disconnect the safety chain or chains from the towing vehicle.

Drawings Figure 1 is a schematic side elevation of a coupling of the present invention in use in relation to a towing vehicle and trailer combination; Figure 2 is a sectional end elevation through a tow bar and slotted member of Figure 1 with a pair of key members in place; Figure 3 is an upper perspective view of the tow bar and slotted member assembly of Figure 2; Figure 4 is a front elevation of a gate and post combination provided with a coupling of the present invention; Figure 5 is a front elevation of another embodiment of gate and post combination provides with a coupling of the present invention; and Figure 6 is an upper perspective view of a modified form of key member for use in a coupling in accordance with the present invention.

In Figures 1 to 3, there is shown a tow bar 10 which is typically attached to a towing vehicle in conventional manner. Underneath the tow bar 10 there is welded a flat slotted metal member 12 provided with a vertical slot 14. The slot 14 has an enlarged portion 16 at its bottom end. The member 12 is conveniently stamped out of metal.

There is also shown a pair of chains 18 attached to a trailer 20 (only part of which can be seen). Each chain 18 has a free end and a flat metal key member 22 is welded to each free end. Each key member 22 comprises a wide body portion 24 at a first end, an intermediate narrow neck portion 26 and a wide bar portion 28 extending at right angles to the neck portion at a second end. The key members 22 are conveniently stamped out of metal.

To attach the chains 18 to the tow bar 10, the key members 22 are inserted sequentially in the slot 14.

To do this a first key member 22 is presented to the slot 14 with the bar portion 28 aligned with the slot 14. The key member 22 is then lowered until the neck portion 26 is in the enlarged portion 16 of the slot 14. The key member 22 can be rotated so that the bar portion 28 is at right angles to the slot 14 (see Figures 2 and 3) and the key member is thus latched to the slotted member. Then, the first key member 22 is raised to the top of the slot 14 and a further key member 22 is presented in similar manner to the slot 14 preferably from the other side of the member 12 (see Figures 2 and 3). The further key member 22 is also inserted and rotated as described for the first key member 22 so that they lie one above the other in the slot 14.It should be noted that the neck portions 26 and slots 14 are so dimensioned that the key member 22 can only be rotated in the slot 14 in the enlarged portion 16 thereof. The fact that the two key members 22 lie one above the other in the slot 14 inhibits rotation of the lowermost key member 22 and thus reduces the possibility of its becoming accidentally disengaged.

To remove the key members 22 from the slot 14, the reverse procedure to that described above is carried out.

Also, in the event that the tow bar becomes disengaged from the trailer in use, it is found that the chains 18 act as a support for the front end of the trailer and prevent it from contacting the road at speed.

In Figures 4 and 5 like reference numerals denote like parts to those found in Figures 1 to 3.

In Figure 4there is shown a gate 20 provided with a slotted member 12 similar to that described above in relation to Figure 1 to 3. It should be noted that the enlarged portion 16 is uppermost. A post 32 has a single chain 18 attached to it and a key member 22 is welded to the free end of the chain 18.

In use, the key member 22 is inserted in the slot 14 as described hereinabove except that it is rotated at the top of the slot at 16 and allowed to drop to the bottom underthe influence of gravity. If an animal such as as a pig, tries to unlatch the gate 30 by lifting the key member 22 from the side thereof it is found that the key member 22 adopts a position in the narrow portion of the slot 14 in which it is laterally inclined in a position between the horizontal and the vertical. This prevents any further movement towards the enlarged portion 16 and thus rotation and disengagement of the key member 22 is prevented.

In Figure 5, there is shown an embodiment similar to that of Figure 4 except that the slotted member 12 is mounted on the post 32 and the chain 18 is passed through an opening in the gate 30 to latch the gate 30 as described above.

In Figure 6 there is shown a modified flat metal key member 40. The key member 40 is intended to replace a key member 22. The key member 40 comprises an intermediate wide body portion 42, and an intermediate narrow neck portion 44 adjacent the body portion 42. A wide bar portion 46 is located at one end of the key member 42 adjacent the narrow neck portion 44. The key member 40 is also conveniently stamped out of metal.

The key member 40 further comprises an aperture 48 adjacent the end of the key member 40 remote from the wide portion 46. Preferably, the outer end of the aperture 48 is defined by a curved loop 50.

Preferably, in the stamping process the loop 50 is formed with a substantially circular-profile. This is because the aperture 48 is used to receive an open end link of a chain (not shown) comprising a series of links. The end link of the chain is closed such as by welding or any equivalent known means once the open link has been passed through the aperture 48.

If loop 50 is too angular in cross-section it tends to be worn away at its corners by the chain links in use.

Therefore, the substantially circular profile is preferred to reduce this wear.

The use of the aperture 48 obviates the need to weld the end link of the chain directly to the key member as is described above in relation to Figures 1 to 5. It is found that the need to make this weld increases the cost of manufacturing the coupling member of the present invention to an unacceptable level because of the costly inspection procedures that are required. The use of the aperture 48 and the closing of an end link of a chain by known means is a much more dependable procedure which reduces manufacturing costs substantially.

It is envisaged that the coupling member of the present invention could also be used as a lifting device and, as described above, for winching boats and for many other purposes.

Modifications and variations of the illustrated embodiments are possible. For example, the chains 18 could be replaced by any equivalent non-rigid connecting means.

Claims

1.A A coupling which comprises a slotted member and a key member, wherein the key member is arranged to be inserted into the slot of the slotted member and to be latched to the slotted member upon being partially rotated.

2. A coupling according to claim 1, which comprises a pair of key members.

3. A coupling according to claim 1 or claim 2, wherein the or each key member comprises a wide body portion, an intermediate narrow neck portion and a wide bar portion generally at right angles to the neck portion at an end remote from the wide body portion.

4. A coupling according to claim 3, in which the slot of the slotted member contains an enlarged portion in which the neck portion can be rotated but the remainder of the slot is too narrow to allow rotation of the neck portion.

5. A coupling according to any preceding claim, in which the or each slotted member is attached to a free end of a chain.

6. A coupling according to claim 3 or claim 4, in which the or each key member comprises an aperture at the end thereof adjacent the wide body portion, which aperture is arranged to receive an open link of a chain which link may be subsequently closed by known means.

7. A coupling member according to claim 6, wherein the outer end of the aperture in the key member is defined by a curved loop.

8. A coupling member substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

8. A coupling member according to claim 7, wherein the curved loop of the outer end of the aperture in the key member has a substantially circular cross-section.

9. A motor vehicle and trailer combination provided with a tow bar for towing the trailer, wherein a slotted member is mounted on the tow bar and two key members arranged to be latched to the slotted member upon being partially rotated in the slot are attached to respective non-rigid connecting means attached to the trailer.

10. A motor vehicle and trailer assembly according to claim 9, in which the slot is vertical and contains an enlarged portion adjacent its lower end, said enlarged portion permitting a key member therein to be rotated to its latched position.

11. A motor vehicle and trailer combination according to claim 9 or claim 10, in which the key members each comprise a wide body portion, an intermediate narrow neck portion and a wide bar portion generally at right angles to the neck portion at an end remote from the wide body portion.

12. A motor vehicle and trailer combination according to claim 11, in which key member comprises an aperture in the wide body portion, which aperture is arranged to receive an open link of a chain which link may be subsequently closed by known means.

13. A gate and post combination comprising a slotted member mounted to the gate or post and a key member attached to a free end of a non-rigid connecting means which is in turn connected to the gate or post, wherein the gate can be latched to the post by inserting the key member into the slot and partially rotating the key member.

14. A gate and post combination according to claim 13, in which the slot is vertical and contains an enlarged portion adjacent its upper end, said enlarged portion permitting a key member therein to be rotated to its latched position.

15. A gate and post combination according to claim 13 or claim 14, in which the key member comprises a wide body portion, an intermediate narrow neck portion and a wide bar portion generally at right angles to the neck portion at an end remote from the wide body portion.

16. A gate and post combination according to claim 15, in which the key member comprises an aperture in the side body portion which aperture is arranged to receive an open link of a chain which link may be subsequently closed by known means.

17. A coupling substantially as hereinbefore described with reference to Figures 1 to 3, Figures 4 and 5 or Figure 6 of the accompanying drawings.

New claims or amendments to claims filed on 28th May 1985 Superseded claims 1-17 New or amended claims:

1. A coupling member which comprises a flat slotted member containing an elongated slot and a pair of flat key members, wherein each key member comprises a wide body portion, an intermediate narrow neck portion and a wide flat portion generally at right angles to the neck portion and at an end remote from the wide body portion, the wide body portion of each key member is attached to a respective flexible element, and the slot of the slotted member is arranged to be orientated vertically in use and contains an enlarged portion which is at the lowermost end of the slot, the enlarged portion being so dimensioned that a neck portion of one key member at a time can be rotated in it but the remainder of the slot being too narrow to allow rotation of the neck portion, such that the key members can be engaged sequentially with the slot by aligning the bars with the slot, pushing each bar through the slot, moving the neck portion until it is in the enlarged portion of the slot and rotating each key member so that its bar engages behind the slotted member.

2. A coupling member according to claim 1, wherein one of the key members has a bar portion which is shorter than the bar portion of the other of the key members, the bar portion of the one key member being of a length such that the one key member can be rotated when the other key member is located in the slot whereas the bar member of the other key member is too long for the other key member to be rotated in the slot when the one key member is located in the slot such that the one key member is arranged to be disposed lowermost in the slot.

3. A coupling member according to claim 1 or 2, wherein the wide body portion of each key member contains an aperture adjacent an end of the key member, which aperture is arranged to receive an open link of a chain which link is subsequently closed.

4. A coupling member according to claim 3, in which the aperture is defined by a curved loop.

5. A coupling member according to claim 3 or 4, in which the aperture is defined by a curved loop of substantially circular cross-section.

6. A motor vehicle and trailer combination provided with a tow bar for towing the trailer, said combination being provided with a coupling member in which a flat slotted member is mounted on the tow bar and a pair of flat key members are attached to the trailer by means of respective flexible elements, wherein the coupling member is as defined in claim 1.

7. A motor vehicle and trailer combination provided with a tow bar for towing the trailer, said combination being provided with a coupling member in which a flat slotted member is mounted on the tow bar and a pair of flat key members are attached to the trailer by means of respective flexible elements, wherein the coupling member is as defined in claim 2.