GB2228516A - Secondary security door - Google Patents

Abstract

A secondary security door for fitting to the door frame externally of an existing door to cover said door includes a box section (4) extending along one edge thereof in which a lock (15) is mounted. The lock is key operated from the outside and manually operated from the inside by, for example, a lever (17) which extends laterally from the lock and protrudes from the box section (4) and is housed in a recess (18b) formed in a central section of the door. A mail box (11) is attached to a recess (10) in this central section thereby reducing the amount that the box (11) protrudes from the front of the door. The door is preferably made of metal and has solid panels 19, 20 or grills. <IMAGE>

Description

SECONDARY SECURITY DOOR This invention relates to a security door and more particularly to what is known as a secondary security door for fitting to the interior of a door frame to cover an existing door mounted thereon whereby the secondary door is juxtaposed or closely adjacent the existing door.

Break-ins through the front, back or side door of domestic and business premises are on the increase.

One way of preventing such break-ins is to fit a metal secondary security door in front of the existing door which cannot be penetrated by an intruder other than with metal cutting equipment.

One of the problems with fitting a secondary security door of this type in front of an existing door is that in the past they have normally included a lock which could only be opened with a key. This presents serious problems from a fire hazard point of view as a person wishing to get out of the door to escape from a fire may not be able to do so because the key may be located in a part of the dwelling which is on fire. Even if it is accessible, a delay would be incurred in finding the key and opening the door which could prove fatal.

It is therefore an object of the invention to provide a secondary security door which can be fitted to the door frame mounting an existing door to cover it and which can be manually opened from the inside without a key and which is cheap and easy to manufacture.

According to the present invention, there is provided a secondary security door for fitting to a door frame to cover an existing door mounted on said frame so as to be juxtaposed or closely adjacent thereto, the security door including a hollow box section along one edge thereof in which a lock is mounted which is key openable only from the exterior of the door but manually openable from the rear thereof. Preferably the door includes a frame of which the box section forms a part, the part of the door within the frame being either solid metal or a metal grille or a combination thereof.

Preferably, the box section extends along the whole length of the door. Conveniently, the door includes a solid metal central section extending between the two sides of the door, to the outside of which a mail-receiving receptacle is attached. In the preferred embodiment, the front face of the mail-receiving receptacle is mounted in a recess in the front of the central section to reduce the amount that said receptacle protrudes from the front of the door.

Preferably, the mail-receiving receptacle has an open top to receive mail therein and also an opening in the rear thereof to permit removal of the mail, the receptacle being of such a size and shape that an intruder cannot gain access to the manually openable lock on the inside of the door through the mail-receiving opening and the rear opening in the mail-receiving receptacle. Conveniently, the opening in the rear of the mail-receiving receptacle is closed by a door which may be spring loaded.

To enhance the appearance of the door, the panel above and below the central section which is contained within the frame may be filled in with a metal grill or with a solid metal panel or a combination thereof, depending on the required appearance of the door.

To facilitate opening of the door from the rear side thereof, a lever preferably protrudes laterally from the lock for manual operation, said lever not protruding beyond the plane of the rear face of the door. This is an important feature of the preferred door of the invention because any such protrusions would increase the effective thickness of the door and thereby could prevent it being accommodated wholly within the depth of the door frame mounting the existing door.

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which Figure 1 is a front view of a door of the invention; Figure 2 is an end view of the door of Figure 1; Figure 3 is a plan view of the door shown in Figures 1 and 2; and Figure 4 is a rear view of the door of Figures 1-3.

Referring to the drawings, there is shown a secondary security door made up from frame parts 1, 2, 3 and 4 welded together. As can be seen from Figure 1, the frame sections 1, 2 and 3 are all of the same cross section whereas the edge frame section 4 is much wider.

Typically, the frame section parts 1, 2 and 3 are 25mm square whereas the frame section 4 is a box section 25mm deep and 75mm wide. These dimensions are given by way of example only and other dimensions can therefore be used. The door also includes cross members 5, 6 also of the same cross section and material as the frame sections 1, 2 and 3. The space between the sections 5, 6 is filled in with a sheet of metal. As can be seen more clearly from Figure 3, this metal sheet is initially flush with the outside surface of the cross members 5, 6 in the regions 7a, 7b but is then bent inwardly at 8a, 8b and then horizontally again to provide a rear wall 9. It will be seen that the configuration of this central panel therefore provides a front recess 10 and two rear recesses 18a, 18b. A mail-receiving receptacle 11 is fitted into the front recess 10 and has a hinged top lid 12.The reason for providing the recess 10 in the front of the door is to reduce the distance that the mail-receiving receptacle 11 protrudes from the front of the door.

The rear wall 9 of the central metal section preferably includes a door 13 therein which may be spring loaded so that access to the interior of the mail-receiving receptacle 11 can be gained from the rear of the door to remove any mail therefrom.

An important feature of the illustrated door and of the present invention is that it includes the box section frame member 4 along its edge remote from hinges 14.

The width of this box section is such that it can readily receive and house a lock 15 therein held in place by screws 16. This lock is securable from the outside by means of a key inserted in keyhole 16 but the door can be opened on the inside by means of a lever 17. The recess 18b immediately adjacent the lock 15 serves to house the lever 17 thereby ensuring that it does not protrude beyond the rear face of the door so the door can be fitted immediately in front of an existing door.

This is most important as the maximum depth available in the door frame to which the secondary security door is to be fitted is normally no more than 40mm and the width of the secondary door is preferably 25mm.

As can be seen from Figures 1 and 4, the frame of the door encloses two areas 19, 20. These can be filled in with either a grill or a solid metal panel depending on the visual appearance required. In the illustrated door, solid infill panels 19, 20 are welded to the surrounding frame. If necessary, additional vertical frame members (not shown) can be provided between the cross frame members 1, 5, 6 and 2.

In order to fit the secondary security door illustrated in the drawings to the frame mounting an existing door, its hinge pins 14 are mounted on the door frame (not shown) and the secondary security door is then fitted thereon by means of its hinge parts 15. Alternatively, a one-piece hinge may be used although, in either case, it is essential that the mounting screws for the hinge assembly must be on the inside of the door frame so as not to be accessible from the outside of the door when it is closed.Once in place on its hinges, the secondary door will be closely adjacent to the front face of the existing door and because the front face of the door is mounted substantially flush with the front face of the existing frame and its edge containing the lock has a lip 25 protruding therefrom to cover the gap between the box section 4 and the adjacent door frame (not shown), it is not possible for an intruder to get a crowbar between the door and the frame and prise the door open.

With the illustrated door, it is not necessary to lock it with a key from the inside because once it has been closed, the catch 24 of lock 15 will engage with its receiving part mounted on the door frame (not shown).

Thus, it is not possible to open the secondary security door from the outside without a key but it can be opened from the inside by means of the lever 17.

It is a preferred feature of the present invention to provide the mail-receiving receptacle 11 on the front face of the door. It should be noted, however, that the design and configuration of the receptacle 11 must be such that it is impossible for an intruder to lift the flap 12 and insert a hand through the top opening and then out through the door 13 at the back of the mail-receiving box and thereby gain access to the lever 17 as this would defeat the object of the secondary door.

The construction of the preferred door just described lends itself very well to mass production as the frame 1-6 can be readily assembled and welded together. The lock 15 is then fitted into the box section 4 whose width is dimensioned such that it will accommodate a standard lock, the box section 4 also including a hole (not shown) through which the operating lever 17 for the lock can protrude. The central section can then be welded into place with the mail receiving receptacle 11 attached thereto and finally the infill panels 19, 20 can be welded in place and the hinges 14, 15 fitted.

Claims (12)

1. A secondary security door for fitting to a door frame to cover an existing door mounted in said frame so as to be juxtaposed or closely adjacent thereto, the security door including a hollow box section along one edge thereof in which a lock is mounted, said lock being key-openable only from the exterior of the door but manually openable from the interior thereof.

2. A security door as claimed in claim 1 wherein the box section extends along substantially the whole length of the door.

3. A security door as claimed in claim 1 or claim 2 wherein the door comprises a central section extending between the two side edges of the door and a mail-receiving receptacle attached to the outside of this central section.

4. A secondary security door as claimed in claim 3 wherein the mail-receiving receptacle is mounted in a recess in the front face of the central section to reduce the amount that said receptacle protrudes from the front of the door.

5. A secondary security door as claimed in claim 3 or claim 4 wherein the mail-receiving receptacle has an opening at the top thereof to receive mail therein and an opening in the rear thereof for the removal of mail, the receptacle being of such a size that an intruder cannot gain access to the manually openable lock on the inside of the door through the top and rear opening of the mail-receiving receptacle.

6. A secondary security door as claimed in claim 5 wherein the rear opening in the mail-receiving receptacle is closed by a door.

7. A secondary security door as claimed in any one of the preceding claims wherein the lock has a lever protruding laterally therefrom to effect its manual operation.

8. A secondary security door as claimed in any one of the preceding claims wherein the rear face of the door has no protrusion therefrom.

9. A secondary security door as claimed in any one of claims 3-8 wherein one or both areas within the frame above and below the central section is or are covered with a metal infill panel.

10. A secondary security door as claimed in claim 9 wherein the or each infill panel is a metal grill.

11. A secondary security door as claimed in claim 9 wherein the or each infill panel is a solid sheet of metal.

12. A secondary security door substantially as herein described with reference to the accompanying drawings.