GB2314585A

GB2314585A - Bolt and handle protector for twist bolt door locks

Info

Publication number: GB2314585A
Application number: GB9713315A
Authority: GB
Inventors: Simon Sturdy
Original assignee: Bloxwich Engineering Ltd
Current assignee: Bloxwich Engineering Ltd
Priority date: 1996-06-26
Filing date: 1997-06-25
Publication date: 1998-01-07
Also published as: GB9713315D0; GB9613442D0

Abstract

A twist bolt door lock fastening mechanism is provided with a security device (20) adapted to enclose at least the pivotal connection (8) and adjacent parts of a handle (7) of the mechanism in the locked position. Access to these parts is therefore prevented unless the security device is destroyed. The device comprises a housing having two parts hinged together and secured in the closed condition by a concealed bolt 24 which can only be removed by partial destruction of the housing and cutting of the bolt. The housing may extend on the opposite side of the twist bolt 1 from the handle to prevent rotation of the bolt 1 even if the handle is removed or damaged.

Description

IMPROVEMENTS IN FASTENING MECHANISMS FOR DOORS This invention relates to improvements in fastening mechanisms for doors of vehicles and of freight containers for the carriage of goods by road, rail or sea.

Our invention is concerned with door fastening mechanisms of the kind in which a substantially vertical operating bar adapted to be mounted in bearings on the door for angular movement about its axis carries on one or each end a fastening member for co-operation with a keeper on a door frame to which the door is hinged about one vertical edge, the bar being moveable by a handle which is connected to the bar by a pivotal connection and which can be positively locked in a locked position corresponding to the full engagement of the or each fastening member with its keeper.

Such a fastening mechanism is herein referred to as a fastening mechanism of the kind set forth.

In a fastening mechanism of the kind set forth, in use the handle may be secured to a hasp or eye on the face of the door by means of a pad lock or a T.I.R. Seal.

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 freight containers, tamper with the goods and then seal up the container again without leaving any obvious evidence of tampering. In some instances thieves have found ways of disengaging the handle of a fastening mechanism to allow rotation of the operating bar, thus disengaging the fastening members from the keepers and then re-engaging them to re-seal the container.

According to our invention a fastening mechanism of the kind set forth is provided with a security device adapted to encapsulate at least the pivotal connection and adjacent parts of the handle and the bar when the handle is in the locked position whereby to prevent access to such parts without destruction of the security device.

When the pivotal connection connects the handle to a hub integral or fast with the bar, the hub and the pivotal connection are sealed from external access by the security device.

When the security device is in its position of use the handle cannot be removed from its locked position. Preferably the security device encapsulates the bar itself by encircling the bar to prevent separation from the hub and consequent rotation of the bar about its axis.

The presence of the security device will indicate that the container has not been subjected to unauthorised entry. Once the container has reached its destination the security device is then removed by a machining operation, suitably grinding.

In one construction the security device is in the form of a box-like structure comprising a cover plate connected at one edge to a sole plate, in combination with a permanent locking mechanism which locks the two plates together against relative movement about the hinge. In use the sole plate is inserted between the bar and the handle in a direction towards the handle and with a cover plate hinged over the bar and the hub and locked in position with a peripheral edge of at least one of the plates in abutment with the other plate and the handle projecting through an opening in the peripheral edge.

The peripheral edge is contoured to receive the bar, and that plate also includes a recess to receive the hub and the pivotal connection.

The security device projects from the axis of the bar in a direction away from the handle through a distance sufficient to prevent the bar from being rotated about its axis, for example should the handle be released from a retainer with which it co-operates in a locked position.

One embodiment of invention is illustrated in the accompanying drawings in which: Figure 1 is a plan view of a fastening mechanism for doors of vehicles and of freight containers; Figure 2 is a plan of a portion of the mechanism showing a security device on an enlarged scale; Figure 3 is an end elevation of the security device; and Figure 4 shows a locking mechanism of the security device on an enlarged scale.

The fastening mechanism illustrated in the drawings comprises a vertical operating bar in the form of a hollow tubular member 1 which is mounted in spaced bearing brackets 2, 3, 4 and 5 on a door for angular movement about its axis. The angular movement of the bar 1 is effected by handle 7 pivotally connected by a pivot pin in the form of a rivet 8 to a hub 9 integrally fast with the bar 1.

In the closed position shown in Figure 1 of the drawings, the handle 7 is generally at right angles to the bar 1, being received in a recess in a retainer 10 in which it is retained by means of a swivel catch 11 pivotally connected to the retainer 10. In this position fastening members 12, 13 at upper and lower ends of the bar 1 and comprising cams co-operate with complementary keepers 14, 15 secured to the top and bottom of a door frame (not shown).

To open the door the swivel catch 11 is moved angularly through substantially 180O which then allows the handle 7 to be released from the retainer 10 by angular movement about the rivet 8. The handle 7 is then moved away from the door to cause angular movement of the bar 1 about its axis, in turn to disengage the cams 12 and 13 from the keepers 14, 15.

As illustrated, when the door is in the closed position shown in the drawings, a security device 20 is fitted to the fastening mechanism.

The device 20 is in the form of a box-like structure comprising a cover plate 21 having a peripheral edge defined by a continuous flange 22 and which is hingedly connected at one edge to a sole plate 23.

A locking mechanism 24 is provided to lock the two plates 21 and 23 together when the device 20 is in its position of use as described below. The locking mechanism 24 comprises a headed pin 25 which is adapted to be inserted through complementary openings 26 and 27 in the two plates 21 and 23, respectively, with the head received in the counterbore 28 in the cover plate 21 and the pin projecting into a counterbore 29 in the sole plate 23. The pin 25 carries retaining means in the form of a snap ring or circlip 30 which is received in a groove 31 in the pin 25 and expands to co-operate with a face 32 at a step at the change in diameter between the opening 27 and the counterbore 29 after the circlip 30 has been forced through the opening 27. A conical lead 33 in the opening 27 is provided to facilitate contraction of the circlip through the opening 27.

In use the sole plate 23 is inserted between the bar 1 and the handle 7 in the direction towards the handle 7 and the cover plate 21 is hinged over the bar and the hub 9 into a position in which the flange 22 abuts against the sole plate 23 and the handle 7 projects an opening 35 in the flange 22. The flange 22 is also contoured to receive the bar 1, and the cover plate 21 also incorporates a recess 35 to receive the hub 9 and the rivet 8. The headed pin 25 is then operated to lock the plates together with the pin 25 inserted into the opening 27 to bring the circlip 30 into abutment with the face 32 as described above. Since the pin 25 is inserted into the device 20 in a direction towards the door, the circlip 30 is inaccessible from the exterior of the fastening.

When the security device 20 is assembled and locked in its position of use it encapsulates the bar 1 itself, the hub 9, the rivet 8, and an inner end portion of the handle 7. Thus the handle cannot be released from its locked position without destruction of security device 20.

The security device 20 projects from the bar 1 along the handle 7 through a distance sufficient to prevent the bar 1 from being rotated about its axis, should the handle, for example, be released from the retainer 10 by cutting through the portion between the retainer 10 and the security device 20. Should such a situation arise any attempts to rotate the bar 1 about its axis will be prevented by the co-operation of the sole plate 23 with the door.

When the container reaches its destination the security device 20 is removed, suitably by a grinding operation against a platform 40 on the sole plate 23 to separate parts of the pin 25. The security device 20 is then removed whereafter the fastening mechanism can be operated in the usual manner.

Claims

1. A fastening mechanism of the kind set forth provided with a security device adapted to encapsulate at least the pivotal connection and adjacent parts of the handle and the bar when the handle is in the locked position whereby to prevent access to such parts without destruction of the security device.

2. A fastening mechanism as claimed in claim 1, in which the pivotal connection connects the handle to a hub integral or fast with the bar, and the hub and the pivotal connection are sealed from external access by the security device.

3. A fastening mechanism as claimed in claim 1 or claim 2, in which the security device encapsulates the bar itself by encircling the bar to prevent separation from the hub and consequent rotation of the bar about its axis.

4. A fastening mechanism as claimed in any preceding claim, in which the security device is in the form of a box-like structure comprising a cover plate connected at one edge to a sole plate, in combination with a permanent locking mechanism which locks the two plates together against relative movement about the hinge, the sole plate being adapted to be inserted between the bar and the handle in a direction towards the handle and with a cover plate hinged over the bar and the hub and locked in position with a peripheral edge of at least one of the plates in abutment with the other plate and the handle projecting through an opening in the peripheral edge.

5. A fastening mechanism as claimed in claim 4, in which the peripheral edge is contoured to receive the bar, and that plate also includes a recess to receive the hub and the pivotal connection.

6. A fastening mechanism as claimed in claim 4 or claim 5, in which the security device projects from the axis of the bar in a direction away from the handle through a distance sufficient to prevent the bar from being rotated about its axis.

7. A fastening mechanism as claimed in any one of claims 4-6, in which the locking mechanism comprises a headed pin which is adapted to be inserted through complementary openings in the two plates, respectively, with the head received in a counterbore in the cover plate, the pin projects into a counterbore in the sole plate and carries retaining means for retaining the pin in the sole plate.

8. A fastening mechanism as claimed in claim 7, in which the retaining means comprises a snap ring or circlip received in a groove in the pin and adapted to expand to co-operate with a face of a step at the change in diameter between the opening in the sole plate and the counterbore after the circlip has been forced through the opening.

9. A fastening mechanism as claimed in claim 8, in which the opening has a conical lead to facilitate contraction of the circlip through the opening.

10. A fastening mechanism substantially as described herein with reference to and as illustrated in the accompanying drawings.