GB2309738A

GB2309738A - Door latching mechanism

Info

Publication number: GB2309738A
Application number: GB9710656A
Authority: GB
Inventors: Peter Charles Remnant
Original assignee: STEELSPACE LYDNEY Ltd
Current assignee: STEELSPACE LYDNEY Ltd
Priority date: 1996-01-25
Filing date: 1996-10-01
Publication date: 1997-08-06
Anticipated expiration: 2016-10-01
Also published as: GB9710656D0; GB2309738B

Abstract

A door latching mechanism 1 comprises latching bolts 19 and 20 and an intermediate bolt 25 attached to a door 2 and movable in relation to the door 2 by a handle 5 pivotable about a pivot axis 16 parallel to the door 2 between a latched position (Figure 3) effecting latching of the latching bolts 19, 20 and 25 and an unlatched position (Figure 4) effecting unlatching of the latching bolts 19, 20 and 25. Bolt 25 projects parallel to but spaced from axis 16. A lock 27 is mounted on the handle 5 so as to be pivotable with the handle 5 and incorporates a locking bolt 28 to lock the handle 5 in the latched position. Furthermore the intermediate bolt 25 increases the security of the locked door as it prevents the latching bolts 19 and 20 from being sprung out of engagement with the door frame by levering of the intermediate region of the door.

Description

"Door latching Mechanisms" This invention relates to door latching mechanisms and is concerned more particularly, but not exclusively, with door latching mechanisms for security site storage containers.

Security site storage containers are used on building sites and in other applications for storage of materials in a secure manner so as to prevent such materials being stolen from site. Such site storage containers are generally in the form of large metal boxes, typically of dimensions about 6m. long and 2.5m. wide and high, having at least one outwardly opening hinged door securable in the closed position by a latch and a key-operated lock. It is known for the door to be fitted with a latching mechanism comprising two sliding bolts extending along a common vertical axis and projecting above and below the door in the latched position, and a handle on the outside of the door which may be pivoted about an axis normal to the plane of the door in order to latch and unlatch the mechanism. Furthermore it is known for a key-operated locking mechanism fixed to the door to incorporate a locking bolt which, when in its locked position, serves to lock the latching mechanism in its latched position. However the locking and latching mechanisms of site storage containers are subjected to considerable abuse by persons attempting to force entry into the containers with a view to stealing materials stored within the containers. For example an intended thief may attempt to introduce a hacksaw blade into a gap around the door with a view to cutting through the locking bolt, or may attempt to couple a vehicle to the handle of the latching mechanism by a chain or rope with a view to exerting a substantial pulling force sufficient to force open the door of the container. Furthermore closing and opening of such a container requires two separate operating actions, namely latching or unlatching by pivoting of the handle, and locking or unlocking by turning of the key, and there is thus a risk that the container may not be securely locked if the latching and locking operations are performed in a hurry. Also the fact that the sliding bolts of the latching mechanism engage only at positions immediately above and below the door in the latched position can mean that the intermediate region of the door is vulnerable to being forced open.

It is an object of the invention to provide an improved door latching mechanism which is particularly adapted for use in this application.

According to the present invention there is provided a door latching mechanism comprising two sliding bolts adapted to be attached to a door so as to extend substantially along a common axis parallel to a major face of the door and so as to be slidable in opposite directions to one another to effect latching or unlatching of the door, and an intermediate bolt adapted to be attached to the door so as to extend parallel to said major face and substantially perpendicularly to said common axis and operatively coupled to the sliding bolts so as to be movable in synchronism with the sliding bolts between a latched position in which the intermediate bolt effects latching of the door in a region intermediate top and bottom regions of the door and an unlatched position in which said intermediate region of the door is unlatched, wherein the intermediate bolt is pivotable about a pivot axis which is substantially parallel to the intermediate bolt but is axially offset therefrom so that the intermediate bolt follows an arcuate path in being moved from its unlatched position to its latched position.

Such an intermediate bolt substantially increases the security of the locked door as it prevents the sliding bolts from being sprung out of engagement with the door frame by levering of the intermediate region of the door.

In a preferred embodiment the sliding bolts are operated by pivoting of an operating arm to which the sliding bolts are pivotally connected, and the intermediate bolt is attached to the operating arm so as to project transversely therefrom. Preferably the sliding bolts are pivotally connected to opposite ends of the operating arm.

Furthermore the intermediate bolt may be fixedly connected to one of the sliding bolts in the region in which said sliding bolt is connected to the operating arm.

Furthermore a pivotable handle is preferably operatively coupled to the bolts and is adapted to be attached to the door so as to be pivotable about a pivot axis substantially parallel to a major face of the door between a latched position effecting latching of the door and an unlatched position effecting unlatching of the door. The operating arm may be fixedly connected to a pivot shaft of the handle such that pivotal movement of the handle causes pivoting of the operating arm.

In one embodiment locking means is provided which is actuable when the handle is in its latched position in order to lock the handle in its latched position. The locking means may comprise a lock mounted on the handle so as to be pivotable with the handle and incorporating a locking bolt which is movable into a locked position when the handle is in its latched position in order to lock the handle in its latched position and which is subsequently movable into an unlocked position in order to permit the handle to be pivoted out of its latched position into its unlatched position.

Preferably the lock is a key-operated lock which is operable by a key inserted through a keyhole in the handle.

Furthermore the pivot axis of the pivotable handle preferably extends substantially horizontally in use, the handle being adapted to be pulled outwardly from its latched position in which it lies substantially parallel to said major face of the door into its unlatched position in which it projects transversely to said major face of the door.

The handle may have an upper portion through which the pivot axis extends and a lower portion which is adapted to be manually grasped from outside the door in order to pivot the handle between its latched position and its unlatched position.

The lower portion of the handle may, for example, have an elongate handle part of generally U-shaped cross-section extending substantially parallel to the pivot axis and adapted to be manually grasped by the user. In this case it is preferred that an outer portion of the handle part is sloped outwardly so as to make it difficult to make a mechanical connection to the handle part with the object of forcing open the door.

An engagement part may be provided adjacent an edge of the door for engagement by the intermediate bolt when the door is closed and the intermediate bolt has been moved along said arcuate path into its latched position. The engagement part may be mounted on an adjacent frame member so as to project behind the door. The engagement part may be in the form of a latching plate welded to the frame member.

Reference is also made to the applicants' copending Patent Application No.

9620463.1.

In order that the invention may be more fully understood, a preferred door latching mechanism in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figures 1 and 2 show the mechanism from outside the container respectively in the latched position and in the unlatched position; Figures 3 and 4 show the mechanism from inside the container respectively in the latched position and in the unlatched position; Figures 5 and 6 show the handle of the latching mechanism from one side and from the front; Figure 7 shows a detail of a modification of the latching mechanism; and Figure 8 shows a modified latching mechanism from inside the container.

The illustrated latching mechanism 1 is provided for latching of double doors of a security site storage container provided for secure storage of materials on a building site. A similar latching mechanism is usable in other applications in which secure locking of doors is required, for example in temporary cabins used for on-site offices or other accommodation for personnel.

Figures 1 and 2 show the outside of the latching mechanism 1 mounted on a door 2 adjacent to the edge 3 of the door where it meets a second door 4 of the outwardly opening hinged double doors of the container, the second door 4 being provided with manually operable upper and lower bolts (not shown) by means of which the door 4 may be secured in the closed position. More particularly Figures 1 and 2 show a pivotable handle 5 of the mechanism respectively in a latched position and an unlatched position permitting the door 2 to be opened outwardly. A guard 6 enclosing the handle 5 has a front opening 7, two vertical side walls 8, a horizontal top wall 9 and a bottom wall 10. The bottom wall 10 has a horizontal portion 11 and an upwardly inclined portion 12, the horizontal portion 11 being provided with a drain hole (not shown) in order to drain rain water out of the bottom of the guard 6. The handle 5 is provided with a handle part 14 of generally U-shaped cross-section which is adapted to be manually grasped in order to pivot the handle 5 upwardly, the opening 7 being dimensioned to allow for passage of the handle part 14 in the unlatched position (Figure 2).

Figures 3 and 4 show the latching mechanism 1 from inside the doors 2 and 4, and show in particular the mounting of the handle 5 within a mounting frame 15 fixed by welding within a cutout in the door 2 (and preferably forming an inner part of the guard 6 projecting through the cutout). An upper portion of the handle 5 is fixedly connected to a pivot shaft 16 extending rotatably through pivot holes 17 in the sides of the frame 15, and an operating arm 18 is fixedly connected to the end of the pivot shaft 16 so as to be pivotable with the handle 5. Respective sliding latching bolts 19 and 20 are pivotally connected to the opposite ends ofthe operating arm 18 by pivot pins 21 and 22. As is well known the bolts 19 and 20 extend substantially along a common axis 23 and project above and below the door 2 in the latched position in order to engage behind upper and lower parts of the door frame, and are slidable in opposite directions to one another as indicated by the arrows 24 in order to effect unlatching of the door 2 (and correspondingly in the reverse directions in order to effect latching of the door).

It will be appreciated that, in the latched position ofthe handle 5 shown in Figure 3, the operating arm 18 extends parallel to the door 2, and the bolts 19 and 20 are therefore at maximum extension. However, when the handle 5 has been pivoted into its unlatched position as shown in Figure 4, the operating arm 18 extends transversely to the plane ofthe door 2 so as to withdraw the bolts 19 and 20 and permit opening ofthe door 2 outwardly. As may be readily seen in Figures 3 and 4, an interrnediate bolt 25 fixed to the bolt 19 in the vicinity of the pivot pin 21 extends transversely to the bolt 19 and is movable during such unlatching operation from a latched position shown in Figure 3, in which the bolt 25 engages behind a latching plate 26 welded to the door 4 in order to latch an intermediate region of the door 2, to an unlatched position shown in Figure 4 in which the bolt 25 is moved clear of the latching plate 26 in order to permit the door 2 to be opened outwardly.

A key operated lock 27 is fixedly secured to the handle 5, for example by means of bolts (not shown) ,so as to be pivotable with the handle 5, as clearly shown in Figures 3 and 4. Furthermore the lock 27 has a locking bolt 28 which, in its locked position shown in Figure 3, engages within a rectangular cutout 29 in the frame 15. The locking bolt 28 is actuable by a key in order to move it between its locked and unlocked positions, and, when in its unlocked position, is withdrawn from the cutout 29 in order to permit pivoting of the handle 5 into the unlatched position shown in Figure 4. A plate 30 (shown in broken lines in Figure 3 in order to render the figure easier to read) is welded to the frame 15 in order to obstruct access to a keyhole 31 of the lock 27 so that the lock 27 cannot be unlocked from inside the container.

Figures 5 and 6 show the handle 5 removed from the mechanism and show in particular the shape of two side walls 32 of the handle 5 one of which is provided with a rectangular cutout 33 for the locking bolt 28 and two holes 34 for the bolts for securing ofthe lock 27. Both side walls 32 also have holes 35 through which the pivot shaft 16 extends and is secured by welding, and the front wall 36 of the handle 5 is provided with a key opening 37 through which a key may be introduced into the keyhole 31 of the lock 27. The shape of the handle part 14 is best appreciated from Figure 5 which shows that the outer portion 38 ofthe handle part 14 is sloped outwardly so as to make it difficult to make a mechanical connection to the handle part 14, for example by attaching a hook at the end of a rope to the handle part 14 with the object of forcing the door open by pulling on the rope with a vehicle.

In certain applications it may be advantageous to provide a secondary locking system for locking the handle 5 in the latched position, so that, when the secondary locking system is locked, the handle cannot be unlatched simply after the lock 27 has been unlocked. Figure 7 shows a modification of the upper part of the handle 5 in the vicinity of the top wall 9 of the guard 6 by welding of an apertured flange 40 to the handle 5 such that the flange 40 passes through a slot 41 in the top wall 9. Normally the flange 40 is capable of moving freely within the slot 41 as the handle 5 is pivoted.

However a padlock may be passed through the aperture 42 in the flange 40 when the handle 5 is in the latched position, shown in Figure 7, and engagement of the padlock with the inside of the top wall 9 on either side of the slot 41 will then serve to prevent subsequent pivoting of the handle 5 into the unlatched position. In an alternative arrangement such secondary locking may be provided by a padlock applied to a part of the guard so as to obstruct movement of the handle. Furthermore, in some applications, such a secondary locking arrangement may be provided in place of the lock 27, rather than in addition to it.

Figure 8 shows a modified latching mechanism 50 from inside the door to which it is attached. The mechanism 50 incorporates a handle 51 within a mounting frame 52 forming an inner part of a guard projecting through a cutout in the door, these parts being of generally similar construction to the corresponding parts of the mechanism 1 described with reference to Figures 1 to 6 except that the handle 51 is pivotable about a vertical axis, rather than about a horizontal axis, and its pivot shaft forms part of a continuously extending vertical latching bolt 54. The latching bolt 54 is provided with transversely extending latching parts 55 and 56 for engaging behind upper and lower portions of the door frame when the latching bolt 54 is pivoted from an unlatched position to a latched position in the direction indicated by the arrow 57. It will be appreciated that in this case the handle 51 is pivotable outwardly of the door about the vertical axis defined by the pivot shaft 53 in order to pivot the latching parts 55 and 56 from the latched position into the unlatched position, and conversely inward pivoting of the handle 51 about the vertical axis is required in order to subsequently place the latching parts 55 and 56 in their latched positions. The handle 51 is then lockable in the latched position by means of the lock 58 having a keyhole 59. Alternatively or additionally a locking arrangement similar to that described with reference to Figure 7 may be provided in such a mechanism.

Claims

1. A door latching mechanism comprising two sliding bolts adapted to be attached to a door so as to extend substantially along a common axis parallel to a major face of the door and so as to be slidable in opposite directions to one another to effect latching or unlatching of the door, and an intermediate bolt adapted to be attached to the door so as to extend parallel to said major face and substantially perpendicularly to said common axis and operatively coupled to the sliding bolts so as to be movable in synchronism with the sliding bolts between a latched position in which the intermediate bolt effects latching of the door in a region intermediate top and bottom regions of the door and an unlatched position in which said intermediate region of the door is unlatched, wherein the intermediate bolt is pivotable about a pivot axis which is substantially parallel to the intermediate bolt but is axially offset therefrom so that the intermediate bolt follows an arcuate path in being moved from its unlatched position to its latched position.

2. A mechanism according to claim 1, wherein the sliding bolts are operated by pivoting of an operating arm to which the sliding bolts are pivotally connected, and wherein the intermediate bolt is attached to the operating arm so as to project transversely therefrom.

3. A mechanism according to claim 2, wherein the sliding bolts are pivotally connected to opposite ends ofthe operating arm.

4. A mechanism according to claim 2 or 3, wherein the intermediate bolt is fixedly connected to one ofthe sliding bolts in the region in which said sliding bolt is connected to the operating arm.

5. A mechanism according to any preceding claim, wherein a pivotable handle is operatively coupled to the bolts and is adapted to be attached to the door so as to be pivotable about a pivot axis substantially parallel to a major face of the door between a latched position effecting latching of the door and an unlatched position effecting unlatching of the door.

6. A mechanism according to claim 5 when appended to claim 2, 3 or 4, wherein the operating arm is fixedly connected to a pivot shaft of the handle such that pivotal movement of the handle causes pivoting of the operating arm.

7. A mechanism according to claim 5 or 6, wherein locking means is provided which is actuable when the handle is in its latched position in order to lock the handle in its latched position.

8. A mechanism according to claim 7, wherein the locking means comprises a lock mounted on the handle so as to be pivotable with the handle and incorporating a locking bolt which is movable into a locked position when the handle is in its latched position in order to lock the handle in its latched position and which is subsequently movable into an unlocked position in order to permit the handle to be pivoted out of its latched position into its unlatched position.

9. A mechanism according to claim 8, wherein the lock is a key-operated lock which is operable by a key inserted through a keyhole in the handle.

10. A mechanism according to claim 5, 6, 7, 8 or 9, wherein the pivot axis of the pivotable handle extends substantially horizontally in use, the handle being adapted to be pulled outwardly from its latched position in which it lies substantially parallel to said major face ofthe door into its unlatched position in which it projects transversely to said major face of the door.

11. A mechanism according to claim 10, wherein the handle has an upper portion through which the pivot axis extends and a lower portion which is adapted to be manually grasped from outside the door in order to pivot the handle between its latched position and its unlatched position.

12. A mechanism according to any preceding claim, wherein an engagement part is provided adjacent an edge of the door for engagement by the intermediate bolt when the door is closed and the intermediate bolt has been moved along said arcuate path into its latched position.

13. A mechanism according to claim 12, wherein the engagement part is mounted on an adjacent frame member and projects behind the door.

14. A mechanism according to claim 13, wherein the engagement part is in the form of a latching plate welded to the frame member.

15. A security site storage container fitted with a door latching mechanism according to any preceding claim.