GB2241526A

GB2241526A - Security door arrangement

Info

Publication number: GB2241526A
Application number: GB9102008A
Authority: GB
Inventors: William Slattery
Original assignee: MCDOWALL WALLACE Ltd
Current assignee: MCDOWALL WALLACE Ltd
Priority date: 1990-02-01
Filing date: 1991-01-30
Publication date: 1991-09-04
Anticipated expiration: 2011-01-30
Also published as: GB2241526B; GB9324008D0; GB9102008D0; GB2272472B; GB2272472A

Abstract

A security door system for protecting a doorway or other aperture in a building which is temporarily unoccupied (for example during refurbishment) comprises a door frame (10, 12, 14, 16) having uprights (10, 12) and lintel (14) of substantially L-shaped section which overlie the doorway and also extend rearwardly into the doorway to prevent the frame being wedged away from the doorway by vandals. A door panel (4) is hinged into the frame and is locked in place by closing and then pressing downwards to engage hooks (76, 78, 80) provided around the periphery of the door panel. <IMAGE>

Description

SECURITY DOOR ARRANGEMENT The present invention relates to a security door system suitable for protecting a doorway or other aperture in a building which is temporarily unoccupied. In particular, the door system may be used for securing empty properties during refurbishment thereof.

Property which is temporarily vacant for one reason or another, for example during building renovation or between tenants, is often subject to damage due to theft and vandalism. Moreover, such property is vulnerable to squatters. Since conventional doors offer relatively little protection against a determined attack, it is necessary to protect them on the outside with an additional door system which is highly resistant to attack and is simple and economic in construction and installation, whilst at the same time affording access to authorised persons.

Such a security door system is disclosed in European Patent 0141623, which describes a security door which must be raised in order to open it. Locking means are provided which merely prevent raising of the door. In its closed position, the door drops into engagement with restraining means which prevent pivotal movement of the door from its closed to open position. The door surround is clamped into the doorway so as to overlap the edges of the doorway, and this allows a single sized door system to be used for a variety of sizes of doorway. However, it has been found in practice that it is possible for a well equipped vandal to breach the door by forcing a wedge between the door surround and the face of the building around the doorway.

It is an object of the present invention to mitigate this problem.

The present invention provides a security door system suitable for protecting a doorway or other aperture in a building, which comprises: - a door frame defining a door opening, which comprises two opposed upright sections, a sill and a top section, at least the uprights and the top section having a cross-section which comprises a front face portion adapted to overlie the doorway in overlapping relationship thereto and a rearwardly extending portion adapted to be received within the doorway; and - a door panel hingedly mounted to an upright section for closing the door opening.

Thus, the essence of the present invention is to provide a door frame wherein at least the upright sections and the top section not only overlie the face of the doorway but extend someway into the doorway. In this way, if a wedge is driven between the front face portion and the wall of the building surrounding the doorway, the wedge may only travel a limited distance before it comes up against the rearwardly extending portion which prevents it being driven in any further.

The upright sections and the top section are preferably formed by bending a sheet of metal into a substantially L-shaped configuration. For additional reinforcement, L-shaped plates may be welded within the section at predetermined intervals.

Preferably, the sill has a minimum upward extent commensurate with adequate strength. This improves ease of access during building renovation work and facilitates bringing wheelbarrows over the threshhold of the door. In the past, it has often been necessary to entirely remove the security door system during building work.

The door frame is usually attached to the opening by means of clamps which nevertheless do not obstruct the opening of the door panel. In particular, the door frame may be attached to a bar extending across the inside of the doorway at positions above and/or below the door opening. Attachment is usually by means of a screw threaded rod screwed to each of the upright sections at one end and bolted to the bar at the other end. To accommodate different sized doorways, the bar mounted on the inside of the doorway may be of variable length,for example by employing two rods, one slideable within the other. If desired, further clamps similar to the type shown in patent specification GB2148442 or EP0141623 may alternatively or additionally be employed, particularly at positions on the frame around the door opening where the use of a transverse bar would obstruct opening of the door panel.

For additional security, it is preferred that the door panel should be provided with restraining means around at least part of its periphery onto which the door drops in its closed position. Such an arrangement is disclosed in patent specification EP0141623. The door panel has to be lifted through a limited vertical distance to disengage the restraining means before the door panel may be opened. A lock is provided which is operative to prevent said vertical movement unless the lock is unlocked. Such a construction has the advantage of being highly resistant to a frontal attack on the door since the brunt of the attack is taken by the restraining means rather than by the lock itself. Moreover, the vandals do not always realise that the door requires to be lifted in order to open it.

The restraining means are preferably in the form of arms extending laterally from the opening side of the door panel, which engage pockets or hooks on the door frame when the door panel is in its lower closed position.

Further restraining means may be provided on the door sill behind which the door panel drops in its closed position. In order to make the door easier to open by authorised persons, it is preferred that spring means be provided which bias the door upwards to counter balance its own weight, so that a slight force has to be applied to move the door downwards into its closed position prior to locking. Such spring means are conveniently provided on the hinges of the door panel.

The door panel itself is generally of a size smaller than a conventional door, so as to enable the door panel to be opened inwards. Alternatively, the door panel may be hinged to open outwards. To prevent insertion of levers by vandals, the gap between the door panel and the frame is preferably protected by an extension of the frame. It is also preferred that an extension of the frame should overlap the gap between the sill and the door panel and this prevents levering of the door panel upwards by vandals.

Embodiments of the present invention will now be described by way of example only with reference to the drawings wherein: Figure 1 is a front elevation of a security door system having an inwardly opening door panel; Figure 2 is a rear elevation; Figure 3 is a partial cross-section along A-A of Figure 1; Figure 4 is a partial section through B-B; Figure 5 is a partial section through C-C; Figure 6 is a partial section through D-D; Figure 7 is a section on E-E of Figure 2 with the frame in place in a doorway but the door panel removed, which shows the sill of the frame; Figure 8 is a sectional view on E-E (Figure 1) of the hinge assembly; Figure 9 is a sectional view (similar to Figure 8) of the hinge assembly of a further embodiment which has an outwardly opening door panel; and Figure 10 is a sectional view (similar to Figure 5) of a hook locking arrangement of the outwardly opening embodiment.

The security door system shown in Figures 1 to 8 comprises a frame 2 having hinged thereto a door panel 4 by means of hinges 6, 8.

The door frame comprises a pair of uprights 10, 12 having welded thereto a top section (i.e. lintel) 14 and a sill 16. The cross-sectional configuration of the uprights 10, 12 can be seen more clearly in Figure 3.

Each upright is formed by folding a single sheet of metal five times so as to form a substantially L-shaped section having a front face portion 14 and a rearwardly extending portion 16. For enhanced rigidity each of the portions is folded to form respective end portions 18, 20 having inturned edges 22, 24 respectively. In the same way, top portion 14,(as shown in Figure 5) comprises a front face portion 26 and a rearwardly extending portion 28 terminating in an end portion 30. As shown more clearly in Figure 6, the sill comprises a lower plate 32 having welded thereto a hollow member 34 and solid bars 36 for restraining the door in the locked position. L-shaped reinforcing pieces 38, 40 are welded into the uprights at regular intervals to improve the rigidity of the uprights.

Respective pieces of angled metal 42, 44 and 46 are spot welded to the inside of the uprights and top section around the door opening so as to protect the gap between the door panel and the door frame. The top angle 46 is wider than the other angles so as to accommodate the vertical movement of the door during locking.

Furthermore, angle 48 is welded to the foot of the door panel itself.

The ends of the rearwardly extending portions of the uprights are used to mount the clamps which clamp the frame to a wall 50 (Figure 7). Thus, upright 12 is provided with a series of holes 52 for attachment of a bolt 54 and nut 56 which passes through one of a corresponding series of holes 58 provided on an extendable clamping bar 60. The clamping bar comprises two metal sections slidable within each other so that the length of the bar may be varied to suit the particular doorway being protected. Each end of the bar is provided with a flat plate 62 having a screw hole therethrough for screwing to a wooden door frame if required. A similar clamping bar 64 is attached to the lower end of the uprights near the sill.

Door panel 4 is hinged to the door frame by means of hinges 6, 8. Each hinge is provided with a respective spring 66 which exerts a force slightly in excess of the weight of the door so as to normally hold the door in its raised position. The door panel is formed by folding a single sheet of metal so as to present inturned edge portion 68 all around its periphery for strengthening. In addition, "top-hat" section channel members 70, 72 and 74 are spot welded onto the rear of the door panel.

Sections 70 and 74 carry the hinges 6, 8 whilst sections 72 carries a protruding strap 76 which engages a corresponding pocket 78 welded to the upright 12 and acts to restrain the door in its lowered lock position.

Furthermore, a hook-section piece 80 is welded to the top of the door panel and hooks over end portion 30 of the top portion of the door frame when the door is in the lowered locked position.

Finally, the door panel carries a lock 82 having a bolt 84 which extends into a corresponding aperture in the frame upright 12. For security, the upright 12 is provided with reinforcing plates 86 around the aperture.

Furthermore, further reinforcing plates 88, 90 are also provided on the door panel and upright respectively to help prevent the lock being forced. The lock may be locked when the door is in the lowered position and the various restraining means are engaged. The door may be lowered against the action of the springs 66 on the hinges by pushing down on handle 92 provided on the front face of the door panel.

The security door system may be operated as follows.

Firstly, the conventional door is unscrewed from its doorway in the wall of the building and the frame is clamped in place as shown in Figure 7, such that the front face portions of the door frame overlie the doorway whilst the rearwardly extending portions extend into the doorway. The door panel is then hung on the hinges and hinged shut. In order to lock the door, a slight downward force is applied to the handle 92 against the action of the hinge springs 66. As the door moves downwards, the base of the door engages behind bars 36 on the sill.

Protruding strap 76 engages in pocket 78 on the frame, and hook member 80 hooks over end portion 30 on the top portion of the frame. In this way, all four sides of the door panel are positively engaged with the door frame. In the door's lowered position, the lock 82 may be operated using a key to send bolt 84 into engagement with the aperture in the frame. In its locked position, the door is very difficult to attack. A frontal attack on the door panel is restrained by the hinges and the restraining means around the other three sides of the door panel. The lock itself is protected by means of plates 88, 90. The lock aperture in the frame is protected by plates 86.

Furthermore, it is difficult to force the frame away from the wall of the building by hammering wedges between the frame and the wall, since the wedges can only travel laterally a limited distance before further movement is prevented by the rearwardly extending portions of the frame.

Figures 9 and 10 show details of a further embodiment having an outwardly opening door panel 104 hinged by hinge 106 (employing a spring as before) to frame upright 110.

The gap between the door and the frame is protected by means of flat straps 143 etc. welded around the sides and top of the door frame (in place of angle pieces 42, 44, 46 in the first embodiment) on the inside of the door panel, thereby allowing the door panel to open outwards.

Figure 10 shows the manner in which the top of the outwardly opening door panel hooks onto the frame on closing and pressing downwards to lock. A hook-section piece 180 is welded to the top 114 of the door frame on the inside thereof, such as to hook under the inturned edge portion 68 of the door when the door panel is pressed downwards.

In other respects the construction of the outwardly opening embodiment is analogous to the inwardly opening version shown in Figures 1 to 8.

The security door system of the present invention is thus highly resistant to a determined attack by vandals yet can be opened easily by authorised personnel having a key. The door is largely made from sheet metal and is therefore economical to produce.

Claims

1. A security door system suitable for protecting a doorway or other aperture in a building, which comprises: - a door frame defining a door opening, which comprises two opposed upright sections, a sill and a top section, at least the uprights and the top section having a cross-section which comprises a front face portion adapted to overlie the doorway in overlapping relationship thereto and a rearwardly extending portion adapted to be received within the doorway; and - a door panel hingedly mounted to an upright section for closing the door opening.

2. A door system according to claim 1 wherein at least the upright sections are substantially L-shaped in transverse section.

3. A door system according to claim 2 wherein the upright sections are formed of sheet material and L-shaped plates are welded at intervals within the sections.

4. A door system according to any preceding claim which further comprises clamp means adapted to extend across the inside of the doorway at positions above and/or below the door opening.

5. A door system according to any preceding claim which further comprises restraining means whereby when the door panel is closed, vertical movement through a limited distance causes the restraining means to become engaged and to prevent hinged movement of the door panel.

6. A door system according to claim 5 wherein the restraining means comprises hook means operative between the frame top section and the top of the door panel when said limited vertical movement occurs.

7. A door system according to claim 5 or 6 which further comprises spring means operative between the door frame and the door panel for substantially counter-balancing the weight of the door panel during said limited vertical movement.

8. A security door system substantially according to either embodiment described in conjunction with the drawings.