GB2248810A

GB2248810A - King-pin disabling device

Info

Publication number: GB2248810A
Application number: GB9019128A
Authority: GB
Inventors: Anton Stanley Mullineux
Original assignee: Trailer Lock Development Ltd
Current assignee: Trailer Lock Development Ltd
Priority date: 1990-09-01
Filing date: 1990-09-01
Publication date: 1992-04-22
Anticipated expiration: 2010-09-01
Also published as: GB9019128D0; GB2248810B

Abstract

A disabling device for a king-pin of a semi-trailer comprises two halves 11, 12, which are internally, hingedly 25 connected and which, when closed, define a cavity closely complementary to the shape of the king-pin and present a substantially uniform external surface 13, 14, 14', and an internal lock 28 for locking the device in its closed position. <IMAGE>

Description

KING-PIN DISABLING DEVICE The present invention relates to a disabling device for the king-pin of a semi-trailer.

The front end of a semi-trailer is carried on a turntable mounted on a tractor vehicle. Tractive effort is transferred to the trailer via a king-pin fast in the trailer beneath the front end of its deck and connected at the centre of the turntable for towing.

Semi-trailers are routinely delivered to a site - for loading, unloading, or parking - by one tractor and collected for transport out to another site by another tractor. When semi-trailers are parked they present a security risk in that an unauthorised tractor may remove a semi-trailer so that its load can be stolen.

Coupling of a tractor and semi-trailer is a routine matter of reversing the tractor up to the semi-trailer, effecting the turntable/king-pin connection, coupling electrical and air lines and withdrawing temporary legs, which hold up the front end of the trailer when it is parked.

A king-pin is simply a pin, fast with a flange at its upper end and having a circumferential groove at its mid-portion. King-pins are of standard dimensions.

A simple padlocked disabling device is available and comprises a pair of hinged together heavy steel strips shaped to fit the king-pin. It operates by getting in the way of and inhibiting connection of the king-pin to a tractor's turntable. However, it is not particularly secure and can be removed from a king-pin with a pair of bolt croppers of suitable size for shearing the pin of the padlock.

The object of the invention is to provide an improved king-pin disabling device.

The device of the invention comprises two halves which are internally, hingedly connected and which, when closed, define a cavity closely complementary to the shape of a king-pin and presenting a substantially uniform external surface and an internal lock for locking the device in its closed position.

Whilst it is envisaged that the external surface of the device may be completely smooth, such as spherical, in order to avoid presenting a conveniently defined target area for attack on the device with a sledgehammer, this objective is achieved in the preferred embodiment by providing it with a right circular cylindrical external surface parallel with the longitudinal axis of the king-pin cavity and a flat end surface normal to this axis. It is also envisaged that other regular external surfaces may be used such as a flat ended right square or hexagonal cylindrical surface.

In order to avoid surface discontinuities as might be attacked with a cold chisel or jemmy, the hinge is preferably provided with a non-single axis hinge, whereby the external surface has a simple joint line between the two halves at the hinge side of the device. In the preferred embodiment, the hinge comprises a peg crossing a recess in one half and a tongue extending from the other half into the recess and having its own slot in which the peg fits. With the lock released, the halves can be separated, with the tongue withdrawing from the recess and the peg moving along the slot, until they are sufficiently separate at the hinge-side joint line for pivotal opening.Preferably the tongue's slot extends obliquely to a joint plane between the two halves, whereby movement of the peg along the slot from its closed position causes a corresponding oblique movement of the two halves, i.e. separation normal to the joint plane is accompanied by a movement along the joint plane. This latter movement is conveniently inhibited by the lock. The lock is preferably positioned opposite the hinge with respect to the cavity. Whilst more complex locks can be envisaged, the lock may be a simple barrel lockable/withdrawable in/from a bore passing through over-lapping parts of the two members.

The cavity in the closed device may be blind, i.e.

covering the end of the king-pin. Alternatively the cavity may be open-ended to allow the distal end of the king-pin to protrude.

The device is preferably of a length to extend closely to the flange of the king-pin to avoid unscrewing of the latter's securing studs. A rim to enclose these may be provided.

To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional side view on the line I-I in Figure 2 of a device of the invention fitted to a king-pin; Figure 2 is an underneath plan view of the device and pin; Figure 3 is a view similar to Figure 2 of the device when open; Figure 4 is a scrap cross-sectional view on the line IV-IV in Figure 2 through a lock of the device, with the trailer pin not shown.

Referring to the drawings, the pin 1 has a flange 2 via which it is fastened to a semi-trailer 3 with studs 4 and nuts 5. The pin has a groove 6, by which it is secured to a tractor in use.

The device 10 has two halves 11,12, which are machined from stainless steel stock. When closed together, the halves present a continuous right circular cylindrical external surface 13, with flat ends 14,14'. The closed halves define an undercut, ribbed bore, which is complementary to the shape of the pin. Particularly, the bore at its lower - in use - end 14 has a portion 15 sized to be a clearance fit on the pin 1. Inwards of the end 14, there is a rib 16 sized to be a clearance fit in the king-pin's groove 6. Above the rib 16, there is a further portion 17 of the same size as the portion 14'. At the end 15, there is a substantial counter-bore 18.

One 11 of the halves has at the general leyel of the rib 16 a pair of tongues 19,20 extending towards the other 12 at a joint plane 21 therebetween. The other half has complementary recesses 22,23. One tongue 19 has a slot 24 extending obliquely to the joint plane at an angle a slightly less than 900. A hinge pin 25 is welded across the recess 22, and engages in the slot 24. The other tongue 20 has a key hole shaped aperture 26, which is aligned with a similar aperture 27 in the other half 12 when the tongue 20 is fully received in its recess 23.

When the device 10 is fitted to the king-pin 1, the hinge pin is received at the end of the slot 24 nearest to the one half 11, and the apertures 26,27 are aligned. In them is fitted a lock 28 with a barrel 29 of a shape complementary to the apertures 26,27, i.e. of circular cross-section with a cut-out section 30 extending from one side of the circle. The cut-out section 30 is blind just above the level of the counter-bore 18, whereby the lock can pass into the counter bore by a small amount x only. The lock has a locking finger 31, which when in its release position is within a lateral extension 32 of a circular section portion 33 of the barrel 29. When in its locked position, the finger 31 extends into the counter-bore as permitted by the small extension of the barrel into the counter-bore and inhibits removal of the lock 28. Thus the device 10 is lockable to the king-pin 1. Because of the angle a of the slot and cooperation with it of the hinge pin, the halves 11,12 cannot rotate apart about the lock 28.

Such action is further inhibited by interengagement of the halves at the joint line radially outwardly of the lock.

For unlocking, the finger 31 is withdrawn from the counter-bore 18, by use of the the lock's key, and the entire lock is removed from the apertures 26,27. By a combined separation of the halves and hinging action as the hinge pin moves along the slot 24, they can be freed from the king-pin, which is now available for use in the normal way.

The invention is not intended to be restricted to the details of the above described embodiment. For instance, the device can be shorter, having the lower end face 14 at the bottom of the rib 16, whereby the device when fitted extends down only as far as the bottom of the groove 6 in the pin 1. Alternatively the device may be extended further down to enclose the end of the pin and define an enclosure for an electronic lock and batteries.

Claims

CLAIMS:

1. A disabling device for a king-pin of a semi-trailer comprising two members, which are internally, hingedly connected and which, when closed, define a cavity closely complementary to the shape of the king-pin and present a substantially uniform external surface, and an internal lock for locking the device in its closed position.

2. A disabling device as claimed in claim 1, wherein the external surface of the device is smooth.

3. A disabling device as claimed in claim 2, wherein the external surface of the device is spherical.

4. A disabling device as claimed in claim 2, wherein the external surface of the device includes a regular, right external surface parallel with the longitudinal axis of the king-pin cavity and a flat end surface normal to this axis.

5. A disabling device as claimed in claim 4, wherein the said regular, right external surface is a right circular cylindrical surface.

6. A disabling device as claimed in claim 4, wherein the said regular, right external surface is a flat ended, right square or hexagonal cylindrical surface.

7. A disabling device as claimed in any preceding claim, wherein the hinge is a non-single axis hinge, whereby the external surface has a simple joint line between the two members at the hinge side of the device.

8. A disabling device as claimed in claim 7, wherein the hinge comprises a peg crossing a recess in one member and a tongue extending from the other member into the recess and having its own slot in which the peg fits, whereby with the lock released, the members can be separated, with the tongue withdrawing from the recess and the peg moving along the slot, until they are sufficiently separate at the hinge-side joint line for pivotal opening.

9. A disabling device as claimed in claim 8, wherein the tongue's slot extends obliquely to a joint plane between the two members, whereby movement of the peg along the slot from its closed position causes a corresponding oblique movement of the two members.

10. A disabling device as claimed in any preceding claim, wherein the lock is positioned opposite the hinge with respect to the cavity.

11. A disabling device as claimed in any preceding claim, the lock is a simple barrel lockable/withdrawable in/from a bore passing through over-lapping parts of the two members.

12. A disabling device as claimed in any preceding claim, wherein the cavity in the closed device is blind.

13. A disabling device as claimed in claim any one of claims 1 to 11, wherein the cavity is open-ended to allow the distal end of the king-pin to protrude.

14. A disabling device as claimed in any preceding claim, wherein the device is of a length to extend closely to the flange of the king-pin to mitigate against unscrewing of the latter's securing studs.

15. A disabling device as claimed in claim 14, wherein a rim is provided to enclose the king pins securing studs.

16. A disabling device as claimed in any preceding claim, wherein within its cavity, the device includes a rib sized to be a clearance fit in a groove in the king-pin.

17. A disabling device for a king-pin of a semi-trailer substantially as hereinbefore described with reference to the accompanying drawings.