GB2266506A

GB2266506A - Anti-jack-knife device for articulated vehicles

Info

Publication number: GB2266506A
Application number: GB9209194A
Authority: GB
Inventors: Norman John Hemingsley
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-04-29
Filing date: 1992-04-29
Publication date: 1993-11-03
Also published as: GB9209194D0

Abstract

A connector assembly for two articulated parts of a vehicle comprises a brake drum 10 on a rotatable shaft 14 non- rotatably connectible to one of said parts, brake shoes (39, Figure 4) engageable with the brake drum to prevent its rotation, the brake shoes being moveable into said engagement by the operation of cams 29 carried on a bracket 28 connected, non- rotatably to the other of said parts, the cams being operable by levers 38 which themselves are operable simultaneously either by application of the brakes of the vehicle or by a separate operating lever in the vehicle cab. The connector assembly prevents jack-knifing of the two parts, and can be overridden when not required. <IMAGE>

Description

CONNECTOR ASSEMBLY FOR ARTICULATED VEHICLES This invention relates to a connector assembly for articulated vehicles and has as its object the provision of a connector assembly which can be fitted, in use, to an articulated vehicle to prevent, or at least minimise, jackknifing.

According to the invention there is provided a connector assembly comprising a part for securement to one element of an articulated vehicle, shaft means rotatable relative to said part and intended to be connected to another element of said articulated vehicle against rotation relative thereto, the shaft means having a first part of braking means rotatable therewith, and there being a second part of the braking means movable into releasable engagement with the first part of the braking means to prevent rotation of said first part and the shaft means, thereby to lock the two elements of the articulated vehicle together.

Preferably the first part of the braking means comprises a brake drum secured to the shaft means and the second part of the braking means comprises a pair of brake shoes within the drum and having pads engageable with the drum to lock the two elements of the articulated vehicle together.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a schematic diametral cross-section through a connector assembly of the invention; 5L I : Figure 2 is a schematic, fragmentary plan view of part of the assembly of Figure 1; Figure 3 is a schematic cross-sectional view through part of the assembly in a direction at 900 to Figure 1; Figure 4 is a top plan view of a second part of braking means of the assembly; Figure 5 is a split view, the left half being a sectional view of said second part of the braking means, the right half being a side view of said second part of the braking means; and Figure 6 is a fragmentary top sectional view of a portion of the second part of the braking means showing a cam engaged with respective ones of a pair of brake shoes.

Figures 1 to 3 show a cylindrical brake drum 10 having a circular disc part 11 from the periphery of which extends, at 900, to a peripheral circular side 12. In the centre of the disc part 11 is a stepped circular aperture 13. Received in the smaller part of this aperture 13 is the hexagonal end of a central shaft 14, this hexagonal end portion extending through an internal collar 15 extending integrally from the inner surface of the disc part 11 around the aperture 13. A cap 16 is fitted in the larger stepped part of the aperture 13 so as to fill it, the cap 16 being secured by a screw 17 to the hexagonal end of the shaft 14.

The hexagonal part of the shaft 14 terminates flush with the end of the collar 15 within the brake drum, and a cylindrical portion 18 of the shaft extends centrally away from the disc part 11 through the remainder of the brake drum. A bearing bush 19 is fitted around this portion 18 of the shaft, the bush resting against the collar 15 with a thrust washer therebetween. The bush 19 is provided with a grease nipple 20.

The end of the cylindrical part of the shaft 14 extends beyond the plane of the open end of the brake drum and received thereon is a spacer 21. The end of this cylindrical part of the shaft 14 is connected to an elbow pin 22 for connection to a conventional connector of, for example, a driven cab. The connector pin has a radially extending part 23 on the end of the portion 18 of the shaft with a stepped cylindrical end portion 24 of the shaft 14 being welded or otherwise connected to an arm plate 25 which at its other end is secured by screws 26 to a cranked end portion 27 of the radially extending part 23. Alternative sizes of elbow pin can be provided, as required, with the spacer 21 being sized accordingly.

Extending diametrically within the brake drum about the shaft 14 is a bracket 28, which has a central circular aperture so that it can be received on the outside of the bush 19 to be supported on the end of the sleeve 15 via the aforementioned thrust washer. The bracket is symmetrical about its central axis so as, in effect, to provide two co-linear arms which extend in radially opposite directions from said centre axis. Each arm is bifurcated at its end, as shown in Figure 1, to mount a cam 29. The side of the bracket 28 remote from the disc part 11 of the brake drum 10 lies just proud of the plane of the outer open end of the brake drum 10, as shown in Figure 1, and welded to this surface of the bracket 28 is a generally disc like base plate 30, the outer diameter of the base plate 30 substantially matching the outer diameter of the brake drum 10 as shown in Figure 3.

Instead, the plate could be integral with the bracket 28.

Each cam 29 has a square section hole 31 therethrough, the cam being carried on a pivot 32. The pivot is formed of three sections, namely a first smaller diameter section 33, a second larger section 34 of square crosssection to fit within the hole 31, and a third larger diameter section 35. The sections 33 and 35 are received in bushes in respective circular holes in spaced forks 36, 37, formed at each bifurcated end of the bracket 28.

A cap is screwed on to the fork 36 over the section 33.

Each cam pivot 32 can turn in its mounting on its forks, such turning causing angular movement of the cam by virtue of the section 34 engaging in the complimentary shaped hole 31 in the cam.

The section 35 of the cam pivot 32 extends out of its associated fork 37 to be received in a circular aperture in an end of a lever 38. As can be seen best from Figure 2, the levers 38 associated with the two cam pivots 32 respectively are diametrically aligned relative to the base plate 30 and are generally parallel to the bracket 28. Each lever is connected to the end of the section 35 by welding. As can be seen from Figures 1 and 2, respective portions of the base plate 30 are cut away to provide angularly extending recesses 30a to receive the respective ends of the levers, each recess being of a size, as will be explained, to allow for angular movement of the lever about its associated cam pivot 32.As can be seen best from Figure 1, each lever extends radially outwardly to a position beyond the side of the brake drum 10, whereupon the lever is stepped downwardly along the side of the brake drum until it is then stepped radially outwardly once again, with an aperture being provided in its outer end.

Contained within the brake drum 10, normally spaced a short distance from the inner surface of its side 12, are a pair of brake shoes 39. Each brake shoe has a semicylindrical peripheral wall 40, to the inner surface of which is welded at right angles a pair of spaced, parallel semi-circular webs 41, 42 respectively. If arranged end to end, the pair of brake shoes effectively complete a circular brake shoe. To the outside of each peripheral wall 40 of the pair of brake shoes 39 are rivetted respective brake pads 43. As can be seen from Figures 4 to 6 the wall 40 of a brake shoe extends beyond its associated brake pad and terminates at the end of the webs at one end of the brake shoe, whilst at the other end the wall 40 terminates flush with the end of the brake pad, this being short of the end of the webs.

As can be seen best from Figure 6, the end of a brake shoe where the wall 40 terminates flush with the webs has a block 44 secured thereto, with a hard plate 45 being secured to the block 44 by countersunk screws 46. The other end of each brake shoe is purely formed by the end of the two webs 41, 42, these being arcuately shaped. As shown in Figure 6, each cam is positioned between adjacent ends of the brake shoes respectively, the brake shoes being arranged so that at one side of the cam is the hard plate 45 of one shoe and at the other side of the cam are the webs 41, 42 of the other brake shoe.

As shown as for the rest position of each cam in Figures 3 to 6, the ends of the webs 41, 42, of one brake shoe extend into associated grooves in a cylindrical outer surface part of each cam. The other side of the cam has its cylindrical surface interrupted by a flat 47, against which the hard plate of the other brake shoe engages.

As shown in Figures 2 and 5, the base plate 30 has a pair of diametrically opposed bores 48, 49 therein spaced 90" around the plate from the recesses 30a. Welded in each bore is a stud 50 which has a stem 51 extending through respective aligned elongated slots 52 in the webs 41, 42, respectively. The stem carries washers 53 at outer sides of the webs and a split pin extends through the stem at its free end to retain the brake shoe half on the stud.

A coiled compression spring 54 disposed around the stem bears at one end against the plate 30 and at its other end against the washer abutting web 42. As shown in the right hand side of Figure 5, spring connectors 55 are also provided between the two webs. Respective extension springs 56 have their opposite ends hooked into holes in one or both of the webs so as normally to bias the two halves of the pair of brake shoes towards one another.

In use, as already mentioned, the elbow pin is connected to a conventional connector of, for example, a driven cab. The levers 38 are interconnected and, in one example, operated by the compressed air or hydraulic fluid of the brakes of the driver's cab. The base plate 30, or a member or frame attached thereto, is secured to a trailer or other articulated member. This securement is normally to a so-called fifth wheel plate of the trailer.

Accordingly normally there could be a certain amount of controlled relative movement between the cab and, for example, its trailer, in that the connection from the cab is through the elbow pin 22, and shaft 24 to the brake drum 10 which is not normally engaged by the brake shoes 39, which themselves have a connection through the base plate to the trailer. However, on operating the brakes of the truck cab, e.g. by compressed air or hydraulic fluid, or by operation of a separate lever in the cab, the levers 38 are each moved angularly in their respective recesses 30a, the movement of each lever being transmitted through its pivot 32 to its associated cam 29.Movement of the cams effectively forces the two brake shoes 39 apart against the bias of the springs 56 so that the brake pads 43 engages tightly against the internal surface of the brake drum 10 so as to prevent its rotation relative to the brake shoes. Accordingly the rotatable part of the assembly, namely the shaft 14 and the brake drum 10 is prevented from rotation relative to the base plate, and thus relative to the trailer to which the base plate is directly or indirectly secured.

Thus upon operating the brakes, or said separate lever in the cab, the cab and the trailer are relatively locked so that jackknifing is thereby avoided.

Although the use of a single drum brake with associated brake shoes has been described, it would be possible to use a symmetrical arrangement of a pair of back-to-back brake drums, each with associated brake shoes again to provide effective anti-jackknifing effect.

In use, when the assembly is fitted to a trailer or like vehicle, a delay system could be incorporated into the actuating means for the levers so that there is a predetermined or variable time delay between operation of the cab brakes and operation of the braking means of the assembly. Additionally or alternatively, an override system could be provided so that the driver in the cab could switch off the interconnection between the cab brakes and the angular movement of the levers of the assembly.

The assembly of the invention can be fitted either to new vehicles/trailers during manufacture or to used vehicles/trailers. Jackknifing due, for example, to the application of heavy braking or climbing hills in snow can now be at least minimised. The assembly will provide a rigid type of body and allows normal vehicle and trailer operation when it is not in use.

A further application of the invention is with railway bogies. The end of the shaft 14 could be welded to the bogie whilst the base plate or equivalent is secured to the top and bottom of a carriage carried by the bogie, or vice versa.

Claims

1. A connector assembly comprising a part for securement to one element of an articulated vehicle, shaft means rotatable relative to said part and intended to be connected to another element of said articulated vehicle against rotation relative thereto, the shaft means having a first part of braking means rotatable therewith, and there being a second part of the braking means movable into releasable engagement with the first part of the braking means to prevent rotation of said first part and the shaft means, thereby to lock the two elements of the articulated vehicle together.

2. A connector assembly as claimed in Claim 1, wherein said part for securement to one element of the articulated vehicle rotatably carries actuating means for moving said second part of the braking means into said releasable engagement with the first part of the braking means.

3. A connector assembly as claimed in Claim 2, wherein said part for securement to said one element of the articulated vehicle is concentric with said shaft and rotatably carries said actuating means at an end of an arm extending radially of said shaft.

4. A connector assembly as claimed in Claim 3, wherein said part concentric with said shaft is formed with a pair of arms extending radially of said shaft in opposite directions at opposite sides thereof, each arm rotatably carrying actuating means at its end.

5. A connector assembly as claimed in any one of Claims 2 to 4, wherein the actuating means is a cam.

6. A connector assembly as claimed in Claim 5, wherein the two cams are arranged to be angularly moved simultaneously on their respective arms upon operation of actuation means.

7. A connector assembly as claimed in Claim 6, wherein said actuation means are brakes of the vehicle.

8. A connector assembly as claimed in Claim 6, wherein said actuation means is an operating lever in a driver's cab of the vehicle.

9. A connector assembly as claimed in Claim 7, wherein there is a time delay, in use, between operation of said vehicle brakes and resultant angular movement of said cams.

10. A connector assembly as claimed in Claim 7 or Claim 9, in which a driver can override the interconnection between the vehicle brakes and the angular movement of the cams, so that the cams are not caused to move angularly when the vehicle brakes are applied.

11. A connector assembly as claimed in Claim 1, wherein the first part of the braking means comprises a brake drum secured to the shaft means and the second part of the braking means comprises a pair of brake shoes within the drum and having pads engageable with the drum to lock the two elements of the articulated vehicle together.

12. A connector assembly as claimed in Claim 11, wherein each brake shoe is connected to the part for securement to one element of the articulated vehicle for relative movement therebetween during locking and unlocking of the elements of the articulated vehicle.

13. A connector assembly as claimed in Claim 11 or Claim 12, wherein at respective ones of their ends the brake shoes have abutments providing respective flat surfaces which engage respective surfaces of first and second cams, each flat surface of the abutment engaging a flat portion of its associated cam surface, when the cams are in their non-actuated positions respectively, and being engaged by an arcuate portion of its associated cam surface, when the cams are in their actuated positions respectively, the engagement by the arcuate portions causing movement of the pads into said engagement with the brake drum, thereby to lock together the two elements of the articulated vehicle.

14. A connector assembly as claimed in Claim 13, wherein each abutment has an insert of hard material secured to it to provide said flat surface of the abutment.

15. A connector assembly as claimed in Claim 13 or Claim 14, wherein at their respective other ends, the brake shoes have respective projections engaging the opposite cams respectively to those engaged at their one ends, each projection and its associated cam having matching arcuate surfaces in engagement.

16. A connector assembly as claimed in any one of Claims 11 to 15, wherein the brake shoes are biased together.

17. A connector assembly as claimed in any one of Claims 13 to 15, wherein said cams are angularly moveable together between their actuated and non-actuated positions by respective levers.

18. A connector assembly as claimed in Claim 17, wherein said part for securement to one element of the articulated vehicle comprises a base part which has respective peripheral, diametrically opposed angularly extending recesses to allow pivoting of said levers to move said cams angularly.

19. A connector assembly as claimed in any one of Claims 13 to 15, or Claim 17 or Claim 18, wherein the first and second cams are each mounted for angular movement between the forks of a bifurcated end of an arm of said part for securement to one element of said articulated vehicle.

20. A connector assembly substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.