AU784401B2 - A locking system for a coupling - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant: ARTHUR GODDARD Invention Title: A LOCKING SYSTEM FOR A COUPLING The following statement is a full description of this invention, including the best method of performing it known to me: 2 A LOCKING SYSTEM FOR A COUPLING The present invention relates to vehicles and is particularly concerned with couplings used for connecting trailers to vehicles.

There are many different ways to connect a trailer to a vehicle.

A typical coupling consists of a tow bar which is connected to the rear of a vehicle and having a U-shaped coupling with the legs of the coupling having aligned eyelets which are adapted to receive a pin therethrough.

A trailer draw bar is generally provided with a tubular hitching block at the coupling end which is adapted to fit between the legs of the U-shaped coupling so that all holes are aligned.

A bolt is then able to be inserted through the aligned holes and can be fixed in position by a screw at the opposite end or a locking pin which is inserted through a lateral hole at the distal end of the bolt.

Typically the bolt is oriented vertically so that the trailer is able to swivel in a horizontal plane with respect to the vehicle.

There are many different types of coupling arrangements for vehicles and trailers but invariably they all have some deficiency. For example the one described above is dependent upon the small lateral pin to keep the bolt in position through the eyelets and holes of the tow bar and draw bar. This has lead to concerns about the durability and therefore safety of this type of coupling.

The present invention is aimed at providing an alternative type of coupling incorporating a novel locking system.

According to the present invention there is provided a locking system for a coupling comprising a pin member, a first coupling component having spaced coupling portions each with holes therethrough aligned along a common axis, a second coupling component having a tubular coupling portion with a hole therethrough and a locking H o :1 SP C 11' 0 C: 3 means which is adapted to retain the pin member in a locked position through the holes of the spaced coupling portions and the hole of the tubular coupling portion when all holes are aligned coaxially, wherein the locking means Scomprises the first locking portion extending from the pin member and a second locking portion associated with the first coupling component.

A locking system for a coupling comprising a pin member having a first locking portion, a first coupling component having spaced coupling portions each with holes therethrough which are coaxially aligned and a second locking portion, a second coupling component having a tubular coupling portion with a passage therethrough and wherein the pin member is adapted to be located through the holes and passage when the tubular coupling portion is S• located between the spaced coupling portions and retained .in position by connecting the first locking portion to the second locking portion.

It is preferred that the first locking portion 2) engages with the second locking portion.

Preferably the first locking portion is fixed to the shaft of the pin member.

co0 Alternatively the first locking portion is :o attachable to the shaft of the pin member.

The first locking portion may comprise a collar with a slot or spigot member.

The slot may comprise an opening through the eoe e collar.

Preferably the second locking portion comprises a spigot member or slot.

The slot may be configured to fit a bayonet-type connection with the spigot member.

It is preferred that the slot comprises first and second regions separated by a narrow region.

It is preferred that one of the regions includes an inner stepped surface which is adapted to seat an underside of the head of a spigot member.

4 The head of the spigot member may be configured to fit through one of the first or second regions.

It should be understood from the above that the bayonet-type connection may be provided by the spigot member/slot configuration being provided on the first locking portion and the second locking portion respectively or vice versa.

Preferably the pin member includes a handle.

The first locking portion may be located below the handle and may be adapted to be located outside the spaced coupling portions.

Preferably the collar comprises a generally planar member with the slot extending across one side thereof.

Alternatively the spigot extends towards one side of the adjacent spaced coupling portion.

It is preferred that the first coupling portion comprises a central body with the spaced coupling portions at opposite ends thereof.

Each of the spirals coupling portions may comprise a laterally extending side wall with one of the holes therethrough.

The second locking portion may be located on an outside surface of one of the spaced coupling portions.

The second locking portion preferably comprises a spigot extending at right angles to the outside surface.

The system may include an urging means for urging the pin member out of the holes and passage.

The urging member may comprise a spring.

Preferably the urging means is adapted to urge the collars away from the outside surface of one of the spaced coupling portions.

The urging means may be adapted to urge the top surface of the inner stepped surface into contact with the underside of the spigot member.

The system preferably includes a detent which in a stop position is adapted to stop movement of the collar H i 1 0 SPEC 0-c 1 06 02" 5 towards the outer surface of the one spaced coupling portion, to disengage the spigot member from the inner stepped surface.

The system may include forcing means for forcing the detent to the stop position.

Preferably the forcing means comprises a spring.

The detent may include a lever which is located adjacent the outside surface of the spaced coupling portion.

The lever may be pivoted at one end.

It is preferred that the lever includes a slot.

Preferably the detent includes a stop member which is fixed to the outside surface of the first coupling component.

It is preferred that the stop member is located within the slot and defines the range of movement of the lever.

Preferably the lever is able to move between a stop position and a release position as defined by inner walls of the slot engaging with the stop member.

In the stop position the lever is preferably located partly below the collar.

In the stop position the lever preferably blocks movement of the collar towards the outer surface of the first coupling component.

According to one embodiment the second coupling component comprises at least two tubular portions which are fixed relative to each other.

Each of the two tubular portions preferably comprise mutually perpendicular passages.

Preferably at least one of the at least one tubular portions comprises two portions, spaced apart and in parallel.

According to another aspect of the present invention there is provided a coupling member comprising at least one tubular portion having a central passage which has wider end regions compared to a central region, 6 the passage being adapted to receive a shaft and at least one end bushing member at each end and whereby in use the shaft is able to at least partially rotate inside the passage.

Preferably the tubular portion comprises a stepped inside surface at each end of the central passage.

The central passage may be cylindrical.

It is preferred that the end regions are cylindrical.

Preferably the stepped inside surfaces separate the end regions from the central passage.

The coupling member may include a mounting means for mounting to a structure.

It is preferred that the bushing members comprise rings.

The rings are preferably made from a plastics material such as polyethylene.

According to one embodiment of the invention each of the perpendicular tubular portions of the second coupling component include one or more of the features of the coupling member aspect of the invention.

According to another aspect of the present invention there is provided a coupling system including the coupling member and a shaft member wherein one end of the shaft member has an end wall against which one end surface of one of the bushings is adapted to abut.

It is preferred that the shaft includes shackle portions at the end wall, for connection to another coupling member.

The words "comprising, having, including" should be interpreted in an inclusive sense, meaning that additional features may also be added.

A preferred embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows a top view of a coupling according to the present invention; H S-,h 1: 6, j 7 Figure 2 shows a side view of the coupling shown in Figure 1; Figure 3 shows a side view of a locking pin for use in the coupling shown in Figure 1; Figure 4 shows an end view of a tow bar coupling component of the coupling shown in Figure 1; Figure 5 shows a top view of a stop mechanism associated with the coupling component shown in Figure 4; Figure 6a shows a top view of a locking mechanism of the coupling shown in Figure 1; Figure 6b shows an end view of the locking mechanism shown in Figure 6a; Figure 7a shows the locking mechanism shown in Figure 6a when in a second mode of operation; Figure 7b shows an end view of the locking mechanism shown in Figure 7a; Figure 8a shows the locking mechanism of Figure 6a when in a third mode of operation; Figure 8b shows an end view of the locking mechanism shown in Figure 8a; Figure 9a shows the locking mechanism shown in Figure 6a in a fourth mode of operation; Figure 9b shows an end view of the locking mechanism shown in Figure 9a;and Figures 10a and 10b show side and end views of an anti-rotation bushing in accordance with the preferred embodiment of the invention.

The coupling 10 shown in Figure 1 consists of a tow bar coupling component 11 which is designed to be attached physically to the tow bar of a vehicle, and a draw bar coupling component 12 which is designed to be attached to a trailer.

The coupling component 11 consists of a pair of metal lugs or towing eyes 13, 14 welded to opposite sides of a rectangular metal bar Each of the lugs 13, 14 have circular openings 16, 17 which are shown more clearly in Figures 4 and ;O d. 0 ,0 8 Both of the holes 16, 17 are axially aligned so part of an intermediate coupling component 18 can be located between the lugs 13 and 14 so that its internal passage is axially aligned with the holes 16, 17.

The intermediate coupling 18 consists of two cylindrical tubular components 19, 20 which are welded together so that they are oriented perpendicular to each other.

Both of the tubular components 19, 20 are welded together at their mid section.

Each of the tubular components 19, 20 has a similar internal configuration. This consists of a central axial passage which is stepped at each end into a passage having a wider diameter.

Each of these end passages is adapted to receive ""annular bushings which are made from a plastics material such as polyethylene. These bushings have an internal diameter effectively the same as the diameter of the central passage.

20 The tow bar coupling component 11 is adapted to oo receive one of the tubular components 19, 20 so that a locking pin 21 is able to be inserted through hole 16, the central internal passage of the tubular component 20 and then through the hole 17 on the opposite side of the 25 component 11. ooooo The locking pin 21 is provided with a shaft 22 which fits through the holes 16, 17 and central internal e oe passage and is provided with a handle 23 at it upper end and a point 24 at its distal end.

A collar 25 is provided in close proximity to the handle 23 and consists of a generally planar metal plate having a generally rectangular shape with one side 26 generally semi-circular.

A slot 27 is provided in close proximity to the side opposite the semi-circular side 26 and extends generally in parallel with the handle 23.

However the slot 27 has a shape similar to a 9 number 8, having end regions 28, 29 generally bulbous with a narrow region 30 therebetween.

One of the bulbous regions 29 is also provided with a stepped inner surface which serves to narrow the width of that bulbous region.

A compression spring 31 is located below the collar One of the lugs 14 which in Figures 6a to 9a appears as the top lug and in Figures 6b to 9b appears as the left most lug, has several surface characteristics which will now be described in more detail.

The upper surface 32 of lug 14 is provided with a fixed bolt 33 having a bolt head 34.

The bolt 33 is located in close proximity to hole 16.

A pivotal detent mechanism 35 is connected through a pivot 36 located near one side of the lug 14.

The detent 35 is in the form of a generally planar lever with a generally cross-wise slot 37 across its widest point.

A bolt 38 extends through the slot and has a head which overlaps the slot abutting its top surface 39 and keeping it in close contact with the upper surface 32 of lug 14.

The lever 35 is generally narrow near pivot 36 and diverges slightly to its widest point proximate the slot 37. It then narrows more quickly to a slightly narrowed distal end 40 which includes a small rectangular stop surface 41 extending at right angles to its distal edge nearest to the hole 16 end of lug 14.

A spring 43 is wrapped around the pivot 36 and has one end located in a hole 44 in a top left hand corner region of lug 14 and the other end 45 retained by a bent keeper portion 46 which is bent upwardly from a mid section at a rear edge of the lever The operation of the locking mechanism will now be described in detail with reference to Figures 3 to 9b.

H SI-C -it) I, PK C 'I 0 0: 10 Once the tubular component 18, 19, 20 has been located between lugs 14 and 13 so that holes 16, 17 and the passage (not shown) are aligned, the locking pin shaft 22 is inserted through the holes and passage and is forced downwardly against the force of the compression spring 31.

Because of the position of the bolt head 34 the slot 27 must be rotated by turning the handle 23 so that the large bulbous region 28 is located over the bolt head 34. This allows the bolt head to pass through the region 28 of slot 27. However before this can occur the detent must be pivoted in an anti-clockwise direction away from the hole 16 to ensure that part of its surface (its widest part) is not located underneath the collar Thus as shown in Figure 6a the lever 35 is pivoted to the left against the force of the spring 43 and the collar 25 is able to be pushed all the way down so that it abuts the upper surface 32 of lug 14.

At this time the bolt head 34 protrudes through the bulbous region 28 of slot 27 and this enables the 20 handle 23 to be rotated clockwise so that the neck of bolt oo o head 34 passes through the narrow region as shown in Figure 7a into the bulbous region 29 as shown in Figure oo •8a ooo o Because the bulbous region 29 is provided with an 25 inner stepped surface 30, by releasing the downward pressure applied to the locking pin 21, the compression spring 31 forces it upwardly and consequently the collar oe into abutment with the underside of the bolt head 34 which overlaps the stepped region 30. Thus the locking pin 21 is prevented from further upward axial movement.

At this time the lever 35 may be released so that spring 43 forces it clockwise and to the right. As a consequence the leading edge of lever 35 at its widest point moves underneath the collar 25. However clockwise movement of the lever 35 is limited to the length of the slot 37 and when the left most side of this slot contacts the bolt 38, as shown in Figure 8a the bolt 38 abuts the 11 left most edge of the slot 37 and the lever 35 is thus unable to move any further.

Because the lever 35 is now partly below collar the collar 25 can no longer be pushed downwardly against the force of the compression spring 31.

At the same time the bolt head 34 rests on the stepped surface 30 and has its periphery located within the bulbous region 29 so that its outer peripheral edge is in close abutting or almost in abutting relationship with the inner surface of the bulbous region 29.

Accordingly it is impossible to rotate the collar anti-clockwise because the head 34 of bolt 33 cannot pass through the narrow region 30 interposing both bulbous regions 28, 29.

The result is that the locking pin 21 is locked in position and cannot be moved unless the lever 35 is moved anti-clockwise as shown in Figure 9a.

When the lever 35 has been moved sufficiently to the left so that no part of it is located below the collar 25 the handle 23 may be pushed downwardly against the force of the spring 31 and rotated anti-clockwise so that the neck of the bolt head 34 can move through the narrow opening into the bulbous region 28 and can then pass through the slot 27 so that the locking pin 21 can move upwardly and out of engagement with the holes 16, 17 and passage of the tubular component (not shown).

From the above it should be clear that the locking pin 21 has a double locking feature because it can be locked in a bayonet-type locking action but cannot be disengaged because of the detent lever 35 being located partly below it.

The intermediate coupling 18 is able to rotate with respect to the locking pin 21.

Likewise the intermediate coupling 18 is also connected through tubular component 19 to the trailer side of the coupling, being component 12.

As shown in Figure 1 the tubular component 19 is S1111.1~~-,, f P 12 located between the legs 50 and 51 of a U-shaped coupling bracket 52.

Openings which are located through both legs 51 are aligned with the internal passage of the component 19 and a bolt is inserted therethrough and is secured in place by a nut at its distal end.

It follows therefore that the tubular component 19 is able to rotate with respect to the bolt 53 and its rotational movement is limited to the point at which the tow bar coupling component strikes the edge of the Ushaped bracket 50. The U-shaped bracket 50 is also provided with a cylindrical shaft extending axially from the centre of the bracket perpendicular to openings through legs 50, 51.

A tubular sleeve 54 is located over the shaft (shown partially as a cut away region in Figure 1).

The tubular sleeve 54 is effectively the same in construction as each of the tubular components 19, However it is much larger.

A bracket plate 56 is attached to the outer surface of the sleeve 54 and is able to be mounted to a trailer.

The end of the shaft 55 is threaded so as to receive a nut 57 and metal gasket 58 which are used to retain the sleeve 54 over the shaft In a similar fashion to the tubular components 19 and 20 annular plastic bushings are located at each end of the sleeve 54 as indicated by item 59 in Figure 1.

With the coupling as described above a trailer may be hitched to a vehicle and when in use the coupling allows movement in three mutually perpendicular planes.

Firstly the intermediate coupling allows movement in a horizontal plane with respect to the tow bar component 11.

Secondly the coupling between the intermediate component 19 and the U-shaped bracket allows movement of the trailer up and down with respect to the tow bar component 11 and finally the sleeve component 54 allows twisting movement j j- t F I t I -1 C 13 of the trailer with respect to the tow bar component 11.

This is a result of the shaft 55 being able to rotate within the sleeve 54 which is fixed.

In addition to the above the locking mechanism provides a double safety feature.

First of all the locking pin 21 enables a bayonet-type locking connection between the intermediate component 18 and the tow bar component 11 and furthermore the detent lever 35 prevents disengagement of the locking pin 21.

Because the handle of the locking pin and the locking mechanism is able to be oriented above the overall coupling it is much easier to see what is going on when engaging or disengaging the coupling components.

In order to control the degree of rotation between the coupling component 12 and the tow bar coupling component 11, a polyurethane bushing as shown in Figures and 10b can be connected to the side of the cylindrical tubular component 19, 20 as shown in Figure 1.

This bushing 60 is bolted through its centre to the side of the tubular component 19, 20 so as to act as a stopper when it is facing the main body of the U-shaped coupling bracket 52. It follows that whenever there is relative movement between the U-shaped coupling bracket 52 and the tubular component 19, 20 the bushing 60 acts as a stopper which restricts this relative movement.

Because the bushing is made of polyurethane it possesses considerable abrasive resistance and therefore has a significant life span in operation. Furthermore because of the bushing and its location a trailer connected to a vehicle through the coupling system experience a significant reduction in rotation relative to the vehicle to which it is coupled.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia !4fH., 1 .P 1'1 'HPFC '1 14 or in any other country.

H f; 1 P; S; Ec 0" C'.

Claims (49)

1. A locking system for a coupling comprising a pin member, a first coupling component having spaced coupling portions each with holes therethrough aligned along a common axis, a second coupling component having a tubular coupling portion with a hole therethrough and a locking means which is adapted to retain the pin member in a locked position through the holes of the spaced coupling portions and the hole of the tubular coupling portion when all holes are aligned coaxially, wherein the locking means comprises the first locking portion extending from the pin member and a second locking portion associated with the first coupling component.

2. The locking system as claimed in claim 1 wherein the first locking portion engages with the second S• locking portion.

3. The locking system as claimed in claim 2 .wherein the first locking portion is fixed to the shaft of the pin member. 20

4. The locking system as claimed in claim 1 or oooo 2 wherein the first locking portion is attachable to the S. shaft of the pin member.

5. The locking system as claimed in any one of the preceding claims wherein the first locking portion 25 comprises a collar with a slot or spigot member. oeeo

6. The locking system as claimed in claim wherein the slot comprises an opening through the collar. eeoc

7. The locking system as claimed in claim 6 wherein the second locking portion comprises a spigot member or slot.

8. The locking system as claimed in claim 7 wherein the slot is configured to fit a bayonet type connection with the spigot member.

9. The locking system as claimed in claim 8 wherein the slot comprises first and second regions separated by a narrow region.

The locking system as claimed in claim 9 16 wherein one of the regions includes an inner stepped surface which is adapted to seat an underside of the head of a spigot member.

11. The locking system as claimed in claim wherein the spigot member comprises a head which is configured to fit through one of the first or second regions.

12. The locking system as claimed in claim 11 wherein the pin member includes a handle.

13. The locking system as claimed in claim 12 wherein the first locking portion is located below the handle and is adapted to be located outside the spaced coupling portions.

14. The locking system as claimed in claim 13 wherein the collar comprises a generally planar member with the slot extending across one side thereof.

The locking system as claimed in claim 14 wherein the spigot member extends towards one side of the adjacent spaced coupling portion.

16. The locking system as claimed in claim wherein the first coupling portion comprises a central body with the spaced coupling portions at opposite ends thereof.

17. The locking system as claimed in claim 16 wherein each spaced coupling portion comprises a laterally extending side wall with one of the holes therethrough.

18. The locking system as claimed in claim 17 wherein the second locking portion is located on an outside surface of one of the spaced coupling portions.

19. The locking system of claim 18 wherein the second locking portion comprises a spigot extending at right angles to the outside surface.

The locking system as claimed in claim 19 including an urging means for urging the pin member out of the holes and passage.

21. The locking system as claimed in claim wherein the urging member comprises a spring. HJ i SPEC 0 17

22. The locking system as claimed in claim 21 wherein the urging means is adapted to urge the collars away from the outside surface of one of the spaced coupling portions.

23. The locking system as claimed in any one of the preceding claims including a bushing located between the first and second coupling components and adapted to oppose relative movement therebetween.

24. The locking system as claimed in claim 22 wherein the urging means is adapted to urge the top surface of the inner stepped surface into contact with the underside of the spigot member.

The locking system as claimed in claim 24 including a detent which in a stop position is adapted to stop movement of the collar towards the outer surface of the one spaced coupling portion, to disengage the spigot member from the inner stepped surface.

26. The locking system as claimed in claim including forcing means for forcing the detent to the stop position.

27. The locking system as claimed in claim 26 wherein the forcing means comprises a spring.

28. The locking system as claimed in claim 27 wherein the detent includes a lever which is located adjacent the outside surface of the spaced coupling portion.

29. The locking system as claimed in claim 28 wherein the lever is pivoted at one end.

The locking system as claimed in claim 29 wherein the lever includes a slot.

31. The locking system as claimed in claim wherein the detent includes a stop member which is fixed to the outside surface of the first coupling component.

32. The locking system as claimed in claim 31 wherein the slot member is located within the slot and defines the range of movement of the lever.

33. The locking system as claimed in claim 32 6 SPEC doc 18 wherein the lever is able to move between a stop position and a release position as defined by inner walls of the slot engaging with the stop member.

34. The locking system as claimed in claim 33 wherein in the stop position the lever is located partly below the collar.

The locking system as claimed in claim 34 wherein in the stop position the lever blocks movement of the collar towards the outer surface of the first coupling component.

36. The locking system as claimed in claim 1 or wherein the second coupling member comprises two parallel tubular portions and one perpendicular tubular portion which are fixed relative to each other.

37. The locking system as claimed in claim 36 wherein each of the two parallel tubular portions comprise S"mutually perpendicular passages.

"38. A locking system for a coupling comprising a pin member having a first locking portion, a first 20 coupling component having spaced coupling portions each o with holes therethrough which are coaxially aligned and a second locking portion, a second coupling component having ooa tubular coupling portion with a passage therethrough and oo wherein the pin member is adapted to be located through 25 the holes and passage when the tubular coupling portion is •oeoo located between the spaced coupling portions and retained in position by connecting the first locking portion to the oo o S•second locking portion.

39. A coupling member configured for use in the locking system claimed in claim 1 and comprising at least one tubular portion having a central passage which has wider end regions compared to a central region, the passage being adapted to receive a shaft and at least one end bushing member at each end and whereby in use the shaft is able to at least partially rotate inside the passage.

The coupling member as claimed in claim 39 19 wherein the tubular portion comprises a stepped inside surface at each end of the central passage.

41. A locking system substantially as hereinbefore described with reference to the accompanying drawings.

42. The locking system as claimed in claim 1 wherein the second coupling component is able to rotate with respect to the pin member.

43. The locking system as claimed in claim 42 including a third coupling component coupled to the second coupling component and rotatable with respect to the second coupling component.

44. The locking system as claimed in claim 43 including a fourth coupling component coupled to the third S 15 coupling component and rotatable with respect to the third S- coupling component.

45. The locking system as claimed in claim 44 wherein the coupling components and pin member allow movement in two mutually perpendicular planes.

46. The locking system as claimed in claim 44 wherein the coupling components and pin member allow movement in three mutually perpendicular planes. wheei

47. The locking system as claimed in claim 44 0 wherein the third coupling component comprises a U-shaped 25 bracket. oooo

48. The locking system as claimed in claim 44 wherein the fourth coupling component comprises a shaft rotatable with respect to a tubular portion of the third coupling component.

49. The locking system as claimed in claim 48 wherein the first coupling component comprises a connection means for connection with a vehicle and the third coupling component comprises a connection member adapted to be connected to a trailer. 20 Dated this 15th day of December 2005 ARTHUR GODDARD By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia *b C. C C C C. CC C C C C CCC C C. C C C. C CCC C~ CC.. C C C C C *.CC CC C C CC C C Ce CCC. CCC e.g