GB2325691A

GB2325691A - Door security strip

Info

Publication number: GB2325691A
Application number: GB9710902A
Authority: GB
Inventors: Barry Kenneth Packman
Original assignee: NT MARTIN ROBERTS Ltd
Current assignee: NT MARTIN ROBERTS Ltd
Priority date: 1997-05-27
Filing date: 1997-05-27
Publication date: 1998-12-02
Anticipated expiration: 2017-05-27
Also published as: GB2325691B; HK1017045A1; GB9710902D0

Abstract

A security strip for a hinged door 11, comprises a cover plate 15, hinge means 16 for mounting the cover plate on the front face of the strike jamb 13 of a door frame 12 so that an edge 18 of the cover plate overlaps the edge 23 of the door when the door is closed, and an interlocking plate 21 which is hinged to the cover plate. The interlocking plate extends between the door edge and the strike jamb, and protrusion means 24 are provided on the interlocking plate for abutment by the edge of the door during its closing movement, whereby closing the door draws the cover plate closed with the protrusion means behind the door thereby resisting the cover plate being opened whilst the door remains closed (figure 4). There is also provided a hinged door and door frame unit having the door security strip.

Description

DOOR SECURITY STRIP AND DOOR AND DOOR FRAME UNIT The invention relates to a door security strip or astragal for a hinged door. More particularly the invention relates to a door security strip which is adapted to be fixed to a door frame for resisting attack, e.g. by a crow bar. The invention also relates to a hinged door and door frame unit having a door security strip mounted on the strike jamb of the door frame. The door security strip is suitable for fitting to new and existing doors.

According to the invention there is provided a security strip for a hinged door, the strip comprising a cover plate, hinge means for mounting the cover plate on the front face of the strike jamb of a door frame so that an edge of the cover plate overlaps the edge of the door when the door is closed, an interlocking plate which is hinged to the cover plate, the interlocking plate extending between the door edge and the strike jamb, and protrusion means on the interlocking plate for abutment by the edge of the door during its closing movement, whereby closing the door draws the cover plate closed with the protrusion means behind the door thereby resisting the cover plate being opened whilst the door remains closed.

Preferably the internal edge of the interlocking plate is turned away from the strike jamb to provide said protrusion means.

It is also preferred that the cover plate, the interlocking plate and said protrusion means all extend over the full height of the door.

Preferably the edge of the cover plate which overlaps the door edge is inturned so that said inturned edge lies in close proximity to the outside face of the door when the door is closed.

The cover plate may be backed by a reinforcing plate.

In one embodiment, the cover plate is spring biased into a predetermined open position.

The interlocking plate may be spring biased against the strike jamb.

The invention also provides a hinged door and door frame unit having a door security strip as defined above mounted on the strike jamb of the door frame.

Preferably the door has retractable door latches which when extended pass through apertures in the interlocking plate into sockets in the strike jamb of the door frame.

Magnet means may be provided in a position for holding open the security strip when the door is open.

By way of example, a specific embodiment of a door security strip in accordance with the invention will be described with reference to the accompanying drawings in which: Figure 1 illustrates a hinged door and door frame unit, with a security strip fitted to the strike jamb of the door frame; Figure 2 shows a top view of the door frame of Figure 1, indicating magnet means for holding open the security strip when the door is open; Figure 3 is a horizontal section along line 3-3 in Figure 1, showing the door closing and making contact with the interlocking plate of the security strip; Figure 4 is a similar sectional view to Figure 3, when the door is closed; and Figure 5 is a detailed perspective view of the door head and strike jamb with the security strip attached thereto.

This example concerns a security strip 10 or astragal for a hinged door 11, which is primarily intended to resist attack using a crow bar or other implement. The door 11 and door frame 12 may be made of wood or metal.

Referring to the drawings, the door security strip 10 is fitted to the strike jamb 13 of the door frame 12 and extends over the full height of the frame from the door head 14 to the floor.

The strip 10 comprises a cover plate 15 which is mounted on the face of the strike jamb 13 by a continuous hinge 16 and attached by fixing screws 17.

An edge 18 of the cover plate 15 overlaps the edge 23 of the door 11 when the door is closed, and is inturned to lie in close proximity with the outside face of the door (Figure 3). The cover plate 15 is backed by a reinforcing plate 19 forming a part of the cover plate over its full width, and the inturned edge 18 of the cover plate is itself supported by a spacer plate 20 between the reinforcing plate and the door.

Projecting inwardly from the cover plate 15 is an interlocking plate 21 which is hinged to the reinforcing plate 19 of the cover plate 15, by a continuous hinge 22. As the door opens, the interlocking plate can initially slide outwardly substantially in parallel relation with the strike jamb 13 whilst the cover plate 15 rotates about the axis of the hinge 16. The interlocking plate 21 extends between the door edge 23 and the strike jamb 13, and its internal edge 24 is turned away from the strike jamb to lie behind the inside face 25 of the door 11 (Figure 3). Thereby, when the door is closed, the strip 10 cannot be wrenched open by a crow bar or other implement inserted between the cover plate 15 and the door 11.

Optionally, magnet means 26 (Figure 2) may be mounted on the door frame as an overhead stop and a device for holding open the security strip at a predetermined angle, e.g. up to 650, when the door is open.

Additionally or alternatively, one or both hinges 16 and 22 may be provided with springs (not shown). A spring on the hinge 16 tends to bias the hinge open to hold the cover plate 15 at a predetermined angle to the strike jamb 13. On the other hand, a spring on the hinge 22 tends to bias the hinge closed to maintain the interlocking plate 21 against the corner of the strike jamb 13 in the position shown in Figure 3. Each spring tensions the strip 10 when the door is closed and locked.

The security strip 10 is applicable for both new and existing doors. In one specific embodiment, the dimensions of the various elements of the security strip are as follows: cover plate : 1.2 mm thick reinforcing plate : 3.0 mm thick spacer plate : 6.0 mm thick two hinges : 25 mm thick interlocking plate : 0.7 mm thick The strip plates may be manufactured from zinc coated mild steel which is primed and painted, or from stainless steel.

Whether it is intended for a new or existing door 11, the security strip 10 is supplied in assembled form, the cover plate 15 and the interlocking plate 21 being sized according to the dimensions of the door frame 12 and door thickness, and the position of the door frame within the opening. The door ironmongery determines the overlap on the door face. The overall width of the strip 10 is determined accordingly, and is mounted on the face of the strike jamb 13 of the door frame 12 by attachment of the hinge 16 with suitable screws 17. The strip is then operated to ensure free and easy action confirming that the turned edge 24 of the interlocking plate 21 locks around the door edge. When the door is closed and locked, the security strip cannot be prised out. After fitting the strip, the positions of the lock deadbolts 27 of the door are determined and cut at 28 into the interlocking plate 21 to allow full locking into the door frame.

During opening of the door 11, the cover plate 15 moves in an arc about the axis of the hinge 16, whilst the other hinge 22 partially closes, allowing the interlocking plate 21 to move substantially parallel to the adjacent surface of the strike jamb 13 with the plate rubbing against the edge of the strike jamb 13.

The cover plate 15 may then be held open by magnet means 26 and/or a spring on hinge 16. The strip then remains open (Figure 3) until the door, as it closes, first engages the interlocking plate and then draws the cover plate closed with the edge 24 disposed behind the door (Figure 4).

Claims

1. A security strip for a hinged door, the strip comprising a cover plate, hinge means for mounting the cover plate on the front face of the strike jamb of a door frame so that an edge of the cover plate overlaps the edge of the door when the door is closed, an interlocking plate which is hinged to the cover plate, the interlocking plate extending between the door edge and the strike jamb, and protrusion means on the interlocking plate for abutment by the edge of the door during its closing movement, whereby closing the door draws the cover plate closed with the protrusion means behind the door thereby resisting the cover plate being opened whilst the door remains closed.

2. A door security strip as claimed in Claim 1, wherein the internal edge of the interlocking plate is turned away from the strike jamb to provide said protrusion means.

3. A door security strip as claimed in Claim 1 or Claim 2, wherein the cover plate, the interlocking plate and said protrusion means all extend over the full height of the door.

4. A door security strip as claimed in any one of the preceding claims, wherein the edge of the cover plate which overlaps the door edge is inturned so that said inturned edge lies in close proximity to the outside face of the door when the door is closed.

5. A door security strip as claimed in any one of the preceding claims, wherein the cover plate is backed by a reinforcing plate.

6. A door security strip as claimed in any one of the preceding claims, wherein the cover plate is spring biased into a predetermined open position.

7. A door security strip as claimed in any one of the preceding claims, wherein the interlocking plate is spring biased against the strike jamb.

8. A hinged door and door frame unit having a door security strip as claimed in any one of the preceding claims mounted on the strike jamb of the door frame.

9. A hinged door and door frame unit as claimed in Claim 8, wherein the door has retractable door latches which when extended pass through apertures in the interlocking plate into sockets in the strike jamb of the door frame.

10. A hinged door and door frame unit as claimed in Claim 8 or Claim 9, including magnet means positioned for holding open the security strip when the door is open.

11. A door security strip substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

12. A hinged door and door frame unit having a door security strip mounted on the frame substantially as hereinbefore described with reference to and as shown in the accompanying drawings.