GB2250541A - Door fastening mechanism - Google Patents

Abstract

The invention relates to a fastening mechanism for doors of goods vehicles and containers comprising a cam-shaped fastening element (1) having two axially spaced claws (2, 3) engageable under axial extensions (7) of a T-shaped head on a keeper (5). The cam element has one or more lugs (11, 21) opposite the claws which cooperate in an anti-racking manner with a lug (10) on the keeper. The lug on the keeper and the or each lug on the cam are provided with aligning holes (12) through which a locking security device (13) can be inserted. Where the cam element has only one lug with a hole in it an axially spaced vestigial lug (14, Figure 1) co-operates with the lug on the keeper to assist in counteracting racking forces. <IMAGE>

Description

DOOR FASTENING MECHANISM This invention relates to fastening mechanisms for the doors of goods vehicles and containers of the kind comprising a rotatable bar carried in bearings adjacent the free edge of the doors and carrying on its ends cam-shaped fastening members which engage respective keepers mounted on the door frame. Such mechanisms are hereinafter referred to as being 'of the kind set forth'.

Such door gear is very widely used on cargo containers and on the rear doors of commercial vehicles. The cams and keepers take various forms, some with a single claw on the cam, others with two spaced claws, and in some there is a so-called anti-racking construction that specifically counteracts forces in a direction parallel to the longitudinal axis of the bar.

The door is usually secured and locked by an arm or handle which extends at right-angles to the bar at a point mid-way in its length and the free end of the arm is secured to a hasp or an eye on the face of the door, for example, by means of a padlock, to prevent the bar being rotated to release the cams.

There is a considerable incentive, especially in the case of vehicles which carry dutiable goods across frontiers, for thieves to be able to break into containers, tamper with the goods or substitute other goods, and then seal up the container again, without leaving any obvious evidence of tampering. In some instances they have found ways of disengaging the locking arm, to allow them to rotate the bar and disengage the fastening members from the keepers, and then re-engage them and seal the container again.

It is therefore desirable to be able to lock the fastening cam directly to its keeper, independently of the bar. An example of an arrangement for doing this is disclosed in British Patent No. 2228526 of A.

Cerutti, published on 29th August 1990. A lug with a hole in it is provided on the keeper and there is an extension of the cam-shaped fastening member, projecting laterally and axially beyond the fastening member and likewise provided with a hole. When the fastening is fully closed these holes are aligned, allowing a padlock or any other form of seal to be passed through the holes.

A similar arrangement, applied to a different form of fastening member, is offered by Powerbrace Europe, which is a subsidiary of White Welding and Mfg. Inc.

In this case there are aligned holes in two spaced ears on the keeper and when the fastening is fully engaged a hole in a part of the cam member comes into line between these ears and, again, a sealing bar can be passed through the holes. This forms the subject of a British Patent Specification No. 2138068A published in 1986.

The aim of the present invention is to provide a new and simpler arrangement on these lines, and for the same purpose, applicable to another known kind of fastening and resulting in a particularly compact structure without excessive projecting elements.

A fastening of the kind set forth comprising a cam-like fastening element of the two claw type in which the claws engage under opposite sides of a substantially T-shaped head on a keeper and having on the opposite side of its axis from the claws a lug which has a hole through it parallel to the axis of the bar, the keeper having on the same side of the axis a single co-operating lug with a hole in it which comes into alignment with the hole in the lug on the cam.

This results in a particularly compact construction of which the dimensions do not extend significantly beyond the boundaries of an orthodox fastening of the type in question without locking holes, and the axes of the holes are close to the axis of rotation of the fastening, keeping to a minimum the stresses induced when an attempt is made to overcome the lock.

Preferably, the lug on the keeper has its central plane (a plane perpendicular to the axis) mid-way between the claws i.e. in the same plane as the centre stem of the head.

The cam may have a single lug on it with a hole in it for co-operation with the hole in the lug on the keeper. In such a construction the single lug may be aligned with one of the claws. The use of a single lug on the cam with a single lug on the keeper ensures minimum weight.

In another construction the cam may be provided with spaced lugs which straddle the lug on the keeper and are provided with aligned holes through them parallel to the axis of the bar. The holes in the spaced lugs on the cam co-operate with the hole in the lug on the keeper when they come into alignment with it.

Some examples of fastening according to the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a partly sectioned front elevation of a fastening with a security pin in place; Figure 2 is a view looking from below in Figure 1; Figure 3 is a view similar to Figure 1 of a modified fastening; Figure 4 is a view looking from below in Figure 3; Figure 5 is a view similar to Figure 1 of another modified fastening; and Figure 6 is a view looking from below in Figure 5.

A forged steel cam-like fastening member 1 mounted on the lower end of a rotatable bar (not shown) has a pair of axially spaced curved upper and lower claws 2,3 which, when the bar is rotated counter-clockwise (as viewed in Figure 2), takes up the closed position shown in the Figures, with the claws 2, 3 engaging under respective axial extensions of a T-shaped head which projects outward from a cast steel keeper 5 of which it forms part. A shank of the head is visible at 6 and one extension is indicated at 7 in Figure 2.

Co-operating inclined surfaces 8 and 9 on the claws and the head of the keeper respectively provide resistance to racking in a known manner.

At the other side of the axis A of the cam there is an integral lug 10 on the keeper 5, projecting outward and having its central plane mid-way between the principal planes of the claws 2 and 3 and aligned with the shank 6. Likewise the fastening 1 has an integral lug 11 a lower face (perpendicular to the axis A) of which is aligned with a lower face of the lower claw 3.

There are holes 12 right through both lugs, parallel to the axis A, and when the fastening is fully closed these holes are aligned, allowing the insertion of a security device. In the example shown it is a security pin 13 of a known kind, such as that made by Blair Products, or it could be a padlock, or a wire seal; the holes have a diameter of 12mm in the preferred example.

It will be understood that the cam and keeper at the other end of the bar may be of the same construction, although in many instances a single lockable fastener is sufficient, the other one being of standard construction.

Cams having lugs on the opposite side of the axis from the claws are known, as exemplified by British Patent Specification No. 1 310 646. In that disclosure the keeper has a head and a lug similar to those described above (but with no hole in the lug) and the cam has two lugs (neither with a hole in it) aligned with the claws on the opposite side of the axis. In the construction shown in Figure 1 there is still a vestigial lug 14 axially spaced from the lug on the fastening member and also aligned with the upper claw but it is short enough to provide clearance for the head of the security pin 13, so there is no increase in the dimensions of the fastener in comparison with the known axes. This is in contrast to those lockable fasteners described earlier.

The vestigial lug 14 has an inclined surface 15 which co-operates with a first inclined surface 16 on the lug on the keeper, the two surfaces co-operating in the closed position to counteract forces parallel to the axis A. A second inclined surface 17 on the lug 10 and an inclined surface 18 on the lug 11 co-operate in a similar fashion to resist forces in the other longitudinal direction.

In the fastening illustrated in Figures 3 and 4 of the drawings, the lug 11 is reduced in radial length to constitute a vestigial lug 20, similar to the lug 14 in the construction of Figures 1 and 2, and the lug 14 is increased in radial length to define a integral lug 21 which is aligned with the upper claw 2. A hole 22 extends fully through the lug 21, in a direction parallel to the axis A. Thus, when the fastening is fully closed the hole 22 is aligned with the hole 12 in the lug 10 to receive the security device 13.

The construction of the fastening of Figures 3 and 4 is otherwise the same as that of Figures 1 and 2, and corresponding reference numerals have been applied to corresponding parts.

In the fastening illustrated in Figures 5 and 6, the second lug 12 is extended in radial length to define the integral lug 21 with a hole 22 through it, as in the construction of Figures 3 and 4.

The two lugs 11 and 21 straddle the lug 10 on the keeper 5 and, when the fastening is fully closed, the hole 22 is aligned with the holes 12, so that the security device 13 can be passed through all three holes.

The construction of the fastening of Figures 5 and 6 is otherwise the same as that of Figures 1 and 2 and corresponding reference numerals have been applied to corresponding parts.

Claims (12)

1. A fastening of the kind set forth comprising a cam-like fastening element having of the two-claw type in which the claws engage under opposite sides of a substantially T-shaped head on a keeper and having on the opposite side of its axis from the claws a lug which has a hole through it parallel to the axis of the bar, the keeper having on the same side of the axis a single co-operating lug with a hole in it which comes into alignment with the hole in the lug on the cam.

2. A fastening according to claim 1, in which axes of the holes are close to an axis of rotation of the fastening.

3. A fastening according to claim 1 or claim 2, in which the lug on the keeper has a central plane perpendicular to the axis mid-way between the claws when the fastening is in a closed position.

4. A fastening according to any preceding claim, in which the cam has spaced lugs which straddle the lug on the keeper and are provided with aligned holes parallel to the axis and which co-operate with the hole in the lug on the keeper in the closed position.

5. A fastening according to any one of claims 1 to 5, in which the cam has a single lug a hole in the lug aligning with the hole in the lug in the keeper.

6. A fastening according to claim 5, in which the lug on the cam is aligned with one of the claws.

7. A fastening according to any preceding claim, in which the T-shaped head comprises an outwardly extending shank and first and second axially projecting extensions under which the claws can engage on opposite sides of the shank.

8. A fastening of the kind set forth comprising a cam-like fastening member having axially spaced upper and lower claws which engage under opposite sides of a substantially T-shaped head on a keeper the fastening member having on the opposite side of the longitudinal axis of the bar from the upper and lower claws a first lug with a hole extending through the lug in a direction parallel to the axis, the keeper having a second lug having a hole in it with which the hole in the first lug aligns, the first and second lugs being so constructed and arranged as to co-operate in a closed position to counteract forces in a direction parallel to the axis.

9. A fastening according to claim 1 or claim 8, in which the fastening member has restraining means axially spaced from the first lug on the cam and adapted to co-operate with the second lug on the keeper to counteract forces in either direction parallel to the axis.

10. A fastening substantially as described herein with reference to and as illustrated in Figures 1 and 2 of the accompanying drawings.

11. A fastening substantially as described herein with reference to and as illustrated in Figures 3 and 4 of the accompanying drawings.

12. A fastening substantially as described herein with reference to and as illustrated in Figures 5 and 6 of the accompanying drawings.