GB2562073A

GB2562073A - Security door with replaceable defensive cassette

Info

Publication number: GB2562073A
Application number: GB1707056.6A
Authority: GB
Inventors: Alan Deevy Thomas
Original assignee: Bastion Security Products Ltd
Current assignee: Bastion Security Products Ltd
Priority date: 2017-05-03
Filing date: 2017-05-03
Publication date: 2018-11-07
Anticipated expiration: 2037-05-03
Also published as: GB201707056D0; GB2562073B

Abstract

A security door having a front face, a back face and edges having a stepped profile, wherein a rear portion (120, Fig. 2A), bounded by the back face lies entirely within the perimeter of a front portion (110, Fig. 2A) bounded by the front face, the door also including a removeable defensive cassette sandwiched between the front and back faces. The front face may be a metal front plate 161 having a gap guard 162 and a hinge side wrap around 163. The frame may have a corresponding stepped profile. The cassette may have a central panel and a frame (181, 182, Fig. 4A), which may be replaced to change or upgrade the doors resistance to certain attacks, without replacement of the entire door. The cassette may have a plywood layer, a ceramic e.g. aluminum oxide layer and a fibre layer e.g. GRP. There may also be a shock absorber having plywood and polystyrene layers. Also claimed is a cassette and a method of manufacture.

Description

(54) Title of the Invention: Security door with replaceable defensive cassette Abstract Title: Security Door with Replaceable Defensive Cassette (57) A security door having a front face, a back face and edges having a stepped profile, wherein a rear portion (120,

Fig. 2A), bounded by the back face lies entirely within the perimeter of a front portion (110, Fig. 2A) bounded by the front face, the door also including a removeable defensive cassette sandwiched between the front and back faces. The front face may be a metal front plate 161 having a gap guard 162 and a hinge side wrap around 163. The frame may have a corresponding stepped profile. The cassette may have a central panel and a frame (181, 182, Fig. 4A), which may be replaced to change or upgrade the door’s resistance to certain attacks, without replacement of the entire door. The cassette may have a plywood layer, a ceramic e.g. aluminum oxide layer and a fibre layer e.g. GRP. There may also be a shock absorber having plywood and polystyrene layers. Also claimed is a cassette and a method of manufacture.

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FIG. 7

SECURITY DOOR WITH REPLACEABLE DEFENSIVE CASSETTE

The present disclosure relates to security doors. More specifically, aspects of the disclosure relate to a security door, a replacement defensive cassette for a security door, a security door system comprising a security door and corresponding frame, and a method of improving the attack resistance of a security door.

Modern security doors must be capable of withstanding brute force impacts, ballistics, cutting tools and even explosives. Many different structures and materials have been developed to increase the time required to defeat security doors.

However, as attack technology advances, security doors must be updated to maintain their level of resistance to attack. Updates are time-consuming and expensive, and also present a significant security risk for the time taken to remove and replace doors.

What is needed is an improved way of updating the specification of a security door to keep up to date with anticipated attack techniques and technology.

According to a first aspect, there is provided a security door having a front face which, in use, is located on an attack side of the door, and a back face which, in use, is located on a non-attack side of the door, joined by edges having a stepped profile so that a rear portion of the door bounded in one direction by the back face lies entirely within a perimeter of a front portion of the door bounded in the opposite direction by the front face such that the door can plug into a corresponding doorframe, the door comprising: a front panel forming the entirety of the front face and at least those parts of the stepped edges bounding the front portion of the door; a removable back panel forming at least the back face of the rear portion of the door; and a defensive cassette sandwiched between the front and back panels for resisting attacks to the door; wherein the components of the door are configured such that the door’s resistance to attack can be varied by removing the back panel, substituting the defensive cassette with a replacement defensive cassette, then replacing the back panel.

The front panel and the back panel can overlap to form the parts of the stepped edges bounding the back portion of the door. The overlapping parts of the front and back panels can be fixed together with fixings which can be removed from the non-attack side. The fixings can comprise one or more of rivets, bolts and screws.

The defensive cassette can comprise: a cassette central panel with edges having a stepped profile so that a front portion of the cassette central panel lies entirely within a perimeter of a back portion of the cassette central panel; and a cassette frame forming part of the front portion of the door, with an interior edge having a stepped profile corresponding to that of the cassette central panel such that the cassette central panel plugs into said cassette frame.

The security door can further comprise: a lock assembly extending through the thickness of the door, including the defensive cassette, from the attack side to the non-attack side, the lock assembly comprising an attack side sub-assembly on the front face and a non-attack side sub-assembly on the back face; and a resilient bracer located between the non-attack side sub-assembly and the defensive cassette, configured to hold the defensive cassette against the front panel in order to prevent backwards warping of the front panel such that gaps form between the front panel and the attack side sub-assembly. The bracer can comprise a plate parallel to the front and back faces and at least two struts extending perpendicularly therefrom, located such that the lock assembly is between them. The lock assembly can comprise two lock cylinders and a handle, configured for simultaneous operation such that more than two hands are required to open the door from the attack side; and the bracer can comprise at least four struts extending perpendicularly from the plate, arranged such that there are at least two struts supporting the portion of defensive cassette surrounding each lock cylinder. The bracer can comprise steel.

One of the edges having a stepped profile can be configured to be hinged to the doorframe, and at least one of the other edges having a stepped profile can have a profile comprising three steps, such that when the door is closed in the door frame the front panel extends over the front-most face of the door frame along that edge, covering the front-most front to back boundary between the door and the doorframe.

One of the edges having a stepped profile can be configured to be hinged to the doorframe, the front panel extending around that edge in two steps around the front and back portions of the door, then turning back on itself such that, in use, it extends over the back-most face of the doorframe.

The defensive cassette can substantially fill the front portion of the door, and the back portion of the door can be substantially filled with a shock absorber. The shock absorber can comprise a layer of wood towards the attack side and a layer of polystyrene towards the non-attack side. The layer of wood comprised in the shock absorber can comprise pressure-treated plywood.

The defensive cassette can comprise at least two layers arranged successively between the attack side and the non-attack side. The defensive cassette layers can comprise: a wood layer towards the attack side; a fibre composite layer towards the non-attack side; and a ceramic layer sandwiched between the wood layer and the fibre composite layer. The defensive cassette wood layer can comprise plywood. The fibre composite layer can comprise glass reinforced plastic (GRP). The ceramic layer can comprise aluminium(lll) oxide (AI₂O₃). The ceramic layer can be at least 3 mm thick, preferably at least 4 mm thick. The ceramic layer can be formed of at least two sub-layers of ceramic tiles, arranged with the tile patterns offset so that the boundaries between tiles in one sub-layer do not align with the boundaries between tiles in any sub-layer adjacent to that sub-layer. The defensive cassette layers can be adhered to one another using an elastomeric adhesive.

The front panel can comprise steel.

The back panel can comprise steel.

According to a second aspect there is provided a replacement defensive cassette configured for substituting the defensive cassette of the security door of the first aspect.

According to a third aspect there is provided a security door system comprising the security door of the first aspect, and the corresponding doorframe.

According to a fourth aspect there is provided a method of improving the attack resistance of a security door according to the first aspect, the method comprising: removing the back panel; removing the defensive cassette; substituting the defensive cassette with a replacement defensive cassette having an improved attack resistance with respect to the previous defensive cassette; and replacing the back panel.

Removing the defensive cassette can comprise: removing the defensive cassette central panel, then removing the defensive cassette frame; and substituting the defensive cassette with a replacement defensive cassette comprises: installing a replacement defensive cassette frame, then plugging a replacement defensive cassette central panel into the replacement defensive cassette frame.

The method can further comprise: prior to removing the back panel, removing one or more lock components from the non-attack face; and subsequent to replacing the back panel, replacing the one or more lock components.

The method can further comprise: between removing the back panel and removing the defensive cassette, removing the shock absorber; and between substituting the defensive cassette and replacing the back panel, replacing the shock absorber.

Aspects of the present disclosure will now be described by way of example with reference to the accompanying figures. In the figures:

Figure 1A illustrates an example security door hanging in a corresponding example doorframe, viewed from the attack side;

Figure 1B illustrates the example security door of Figure 1A hanging in the corresponding example doorframe, viewed from the non-attack side;

Figure 2A is a top view of the example door of Figures 1A and 1B;

Figure 2B is a handle-side view of the example door of Figure 2A;

Figure 3 shows a horizontal cross-section through the example door and corresponding doorframe of Figures 1A and 1B;

Figure 4A shows another horizontal cross section through the door of the previous figures, this time absent the doorframe;

Figure 4B shows a vertical cross section through the example door of the preceding figures at the location of the lock assembly;

Figure 4C shows another horizontal cross section through the example door of the preceding figures, this time taken at the level of the lower lock cylinder;

Figure 5 shows an exploded view of some of the components of the example door of the preceding figures;

Figure 6 illustrates as example defensive cassette; and

Figure 7 is a flowchart showing an example method of improving the attack resistance of an example security door.

The following description is presented to enable any person skilled in the art to make and use the system, and is provided in the context of a particular application. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art.

The terms “top”, “bottom”, “side”, “front”, “back”, “forward”, “rear” and other terms describing the orientation of features are not intended to be limiting and are purely included in order to facilitate the description of the relative location of these features in the context of the accompanying drawings. In use, or during storage, the features may be disposed in other orientations.

What is proposed is a modular structure for a security door, which allows the door to remain hanging in its frame while its security specification is updated.

This is achieved by providing the door with an internal defensive cassette which can be removed and replaced from the non-attack side.

The door comprises a front portion with a relatively large footprint in the plane of the door opening (which, in use, is positioned on the side vulnerable to attack) and a rear portion with a relatively small footprint in the plane of the door opening (which, in use, is positioned on the non-attack side). The door can thus be plugged into a corresponding doorframe such that the door can only be opened in a direction towards the attack side, since the presence of the doorframe behind the edges of the front portion blocks opening in a direction away from the attack side. The stepped edges also mean that the boundary between the door and the doorframe follows a tortuous path from attack side to non-attack side, providing resistance to ballistics attacks and to attempts to drive a wedge between the door and the doorframe to create a gap between them.

The stepped profile of the door edges and corresponding portions of doorframe may be provided all the way around the perimeter of the door, or only in some parts. For example, if it would be inconvenient for there to be a step created by a portion of doorframe along the bottom edge, the frame could be three sided, with the lower door edge being flat rather than stepped (though providing the stepped profile around the entire door perimeter is more secure.)

The door skin is formed of a front panel and a back panel, for example of steel, with the join between them not being visible from the attack side. To achieve this, the front panel extends over the entire front face of the door, and around at least the edges of the front portion.

Within this skin a defensive cassette is provided for resisting attacks to the door. The specification of the defensive cassette can be varied depending on the type of attacks anticipated, and any limiting factors (e.g. budget or availability of materials). For example, different defensive cassettes might be optimised for resisting cutting attacks, blunt force attacks or ballistics attacks, or may be configured to provide a good balance of defence to all known attack technologies.

The back panel is configured such that it can be removed and replaced from the non-attack side of the door. With the back panel removed, the defensive cassette is accessible for removal and updating.

Figures 1A and 1B illustrate an example security door 100 hanging in a corresponding doorframe 200. Figure 1A shows a view from the attack side, and Figure 1B a view from the non-attack side. In this example the doorframe completely surrounds the door, as can be seen in Figure 1B.

Figure 2A is a top view of the door 100 of Figures 1A and 1B, illustrating the presence of a front portion 110, which is wider than a rear portion 120. A hinge connection 130 is shown on the left hand edge as drawn. A lock assembly is shown towards the right hand edge as drawn (i.e. on the side opposing the hinge connection). The lock assembly comprises an attack side sub-assembly 140, including a handle, and a non-attack side sub-assembly 150.

Figure 2B is a handle-side view of the door 100 of Figure 2A. This illustrates that the front portion 110 is taller than the rear portion 120. It also shows that, in this case, the attack side sub-assembly 140 comprises a handle 141 and two keyholes 142. Providing more than two elements to the attack side subassembly, all of which must be operated simultaneously to open the door, means that even someone in possession of both keys would require assistance from a second person to open the door.

Figure 3 shows a horizontal cross-section through the door 100 of the preceding figures, to illustrate how it is hung in the doorframe 200. This shows how doorframe 200 has a stepped inner edge profile corresponding to the stepped edge profile of the door 100. When the door is closed, the edges of the front portion 110 of the door abut the inner edges of a front portion 210 of the doorframe, and the edges of the rear portion 120 of the door abut the inner edges of a rear portion 220 of the doorframe.

A front panel of the door comprises a front plate 161, a gap guard 162 and a hinge-side wraparound 163. All of these components can be made from a single piece, e.g. of steel. The gap guard 162 is an extension of the front plate 161 over the front face of the front portion 210 of the doorframe 200. In this example, the gap guard 162 covers the boundary between the door 100 and the doorframe 200 on all edges except for the hinge side edge. These edges thus have a profile with three steps, making the boundary extremely tortuous. A gap guard cannot be used on the hinge side, as this would prevent the door from functioning. The hinge side edge profile therefore only has two steps. However, the hinge side edge is provided with the hinge-side wraparound 163. This is an extension of the front plate 161 which extends around the hinge side edge of the door, hugging the stepped edge profile of the doorframe all the way around to its back face. This creates another tortuous gap path to foil ballistics and wedge attacks.

Figure 4A is another cross section through the door 100 of the previous figures, this time absent the doorframe. The cross section is taken horizontally, just above the main part of the non-attack side sub-assembly 150. This figure illustrates an example internal construction, as well as an example of how the front and back panels are joined.

The skin of the door 100 comprises a front panel and a back panel 170. In this example, the back panel 170 wraps around the edges of the rear portion 120 of the door 100. The front panel is formed of the front plate 161, the gap guard 162, the hinge-side wraparound 163 (not shown in Figure 4A), and an edge wraparound 164. The edge wraparound 164 follows the stepped edge profile around the edge of the front potion 110 of the door 100, onto the edge of the rear portion 120 of the door 100, where it overlays the back panel 170. Holes are provided through both the edge wraparound 164 and the back panel 170 along the edges they overlap on, to receive reversible fixings (e.g. bolts or screws) to fix them together. The fixings are supported by fixing frame 195.

Within the door skin, the front portion 110 of the door 100 is filled with a defensive cassette. The defensive cassette comprises a cassette central panel

181 plugged into a cassette frame 182. The cassette central panel 181 and cassette frame 182 fit together by means of a stepped edge connection.

The rear portion 120 of the door 100 comprises a shock absorber. In this example, the shock absorber comprises a pressure-treated plywood panel 191 directly behind the cassette and a polystyrene panel 192 between the plywood panel 191 and the back panel 170. The shock absorber helps to spread out forces applied to the cassette from the attack side. It also provides sound and heat insulation.

Also shown in Figure 4A is a resilient bracer comprising a bracer plate 193 and bracer struts 194. The bracer acts to hold the defensive cassette and front plate 161 flush against the attack side lock assembly components. This foils attacks intended to dish the door material around the keyholes 142 to provide access for vertical cutting of the lock assembly. This is shown in more detail in Figure 4B, which is a vertical cross section at the location of the lock assembly. In this example four bracer struts 194 are provided, alternating up the height of the door with the lower keyhole 142, handle 141 and upper keyhole 142. Each keyhole 142 is thus supported by two struts, one above and one below.

Figure 4C is another horizontal cross section through the door 100 of the preceding figures, this time taken at the level of the lower lock cylinder, to illustrate how the lock assembly passes through the thickness of the door 100.

Figure 5 shows an exploded view of some of the components of the door 100, as already discussed.

Figure 6 illustrates as example defensive cassette 600, such as may be used in the example door 100 of Figures 1 to 5. It comprises three layers wrapped in a plastic coating 610 to conceal the construction and help hold the layers together. They may also be affixed to one another using e.g. elastomeric adhesive.

The layer 620 closest to the attack side comprises wood, for example plywood. This could for example be 15 to 25 mm thick, for example 18 to 20 mm. The middle layer 630 comprises ceramic, for example AI₂O₃. This could for example be 3 to 10 mm thick, for example 4 to 5 mm. It could be formed of tiles. If multiple layers of tiles are used, they could be laid like bricks so that tile boundaries in one layer do not overlie tile boundaries in any adjacent layer, strengthening the construction. The layer 640 closest to the non-attack side comprises fibre composite, for example glass-reinforced plastic (GRP). This could for example be 3 to 10 mm thick, for example 4 to 5 mm.

The plywood layer 620 protects the ceramic layer 630 from impact, while the ceramic layer 630 offers protection against cutting. The fibre composite layer protects against ballistics attacks.

Figure 7 is a flowchart showing a method 700 of improving the attack resistance of a security door such as example door 100 of Figures 1 to 5. At step 710 lock components, such as non-attack side sub-assembly 150, are removed. At step 720 a back panel, such as back panel 170, is removed. At step 730, a shock absorber is removed. At step 740, a defensive cassette is removed. This step may be split into sub-steps 741 and 742, where sub-step 741 is to remove a cassette central panel, such as cassette central panel 181, and sub-step 742 is to remove a cassette frame, such as cassette frame 182. Then, at step 750 a replacement cassette is installed. This can comprise sub-steps 751 and 752, where sub-step 751 is to install a replacement cassette frame, and sub-step 752 is to install a replacement cassette central panel. Next, at step 760, the shock absorber is replaced. Then then the back panel is replaced at step 770 and finally the lock components at step 780. All of these steps can be carried out from the non-attack side with the door still closed in its doorframe. In this way, no one on the attack side can see that any work is taking place.

Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the embodiments disclosed herein. It is intended that the specification and examples be considered as exemplary only.

In addition, where this application has listed the steps of a method or procedure in a specific order, it could be possible, or even expedient in certain circumstances, to change the order in which some steps are performed, and it is intended that the particular steps of the method or procedure claims set forth herein not be construed as being order-specific unless such order specificity is expressly stated in the claim. That is, the operations/steps may be performed in any order, unless otherwise specified, and embodiments may include additional or fewer operations/steps than those disclosed herein. It is further contemplated that executing or performing a particular operation/step before, contemporaneously with, or after another operation is in accordance with the described embodiments.

Claims

1. A security door having a front face which, in use, is located on an attack side of the door, and a back face which, in use, is located on a non-attack side of the door, joined by edges having a stepped profile so that a rear portion of the door bounded in one direction by the back face lies entirely within a perimeter of a front portion of the door bounded in the opposite direction by the front face such that the door can plug into a corresponding doorframe, the door comprising:

a front panel forming the entirety of the front face and at least those parts of the stepped edges bounding the front portion of the door;

a removable back panel forming at least the back face of the rear portion of the door; and a defensive cassette sandwiched between the front and back panels for resisting attacks to the door;

wherein the components of the door are configured such that the door’s resistance to attack can be varied by removing the back panel, substituting the defensive cassette with a replacement defensive cassette, then replacing the back panel.

2. The security door of claim 1, wherein the front panel and the back panel overlap to form the parts of the stepped edges bounding the back portion of the door.

3. The security door of claim 2, wherein the overlapping parts of the front and back panels are fixed together with fixings which can be removed from the non-attack side.

4. The security door of claim 3, wherein the fixings comprise one or more of rivets, bolts and screws.

5. The security door of any preceding claim, wherein the defensive cassette comprises:

a cassette central panel with edges having a stepped profile so that a front portion of the cassette central panel lies entirely within a perimeter of a back portion of the cassette central panel; and a cassette frame forming part of the front portion of the door, with an interior edge having a stepped profile corresponding to that of the cassette central panel such that the cassette central panel plugs into said cassette frame.

6. The security door of any preceding claim, further comprising:

a lock assembly extending through the thickness of the door, including the defensive cassette, from the attack side to the non-attack side, the lock assembly comprising an attack side sub-assembly on the front face and a nonattack side sub-assembly on the back face; and a resilient bracer located between the non-attack side sub-assembly and the defensive cassette, configured to hold the defensive cassette against the front panel in order to prevent backwards warping of the front panel such that gaps form between the front panel and the attack side sub-assembly.

7. The security door of claim 6, wherein the bracer comprises a plate parallel to the front and back faces and at least two struts extending perpendicularly therefrom, located such that the lock assembly is between them.

8. The security door of claim 7, wherein:

the lock assembly comprises two lock cylinders and a handle, configured for simultaneous operation such that more than two hands are required to open the door from the attack side; and the bracer comprises at least four struts extending perpendicularly from the plate, arranged such that there are at least two struts supporting the portion of defensive cassette surrounding each lock cylinder.

9. The security door of any of claims 6 to 8, wherein the bracer comprises steel.

10. The security door of any preceding claim, wherein one of the edges having a stepped profile is configured to be hinged to the doorframe, and at least one of the other edges having a stepped profile has a profile comprising three steps, such that when the door is closed in the door frame the front panel extends over the front-most face of the door frame along that edge, covering the front-most front to back boundary between the door and the doorframe.

11. The security door of any preceding claim, wherein one of the edges having a stepped profile is configured to be hinged to the doorframe, the front panel extending around that edge in two steps around the front and back portions of the door, then turning back on itself such that, in use, it extends over the back-most face of the doorframe.

12. The security door of any preceding claim, wherein the defensive cassette substantially fills the front portion of the door, and the back portion of the door is substantially filled with a shock absorber.

13. The security door of claim 12, wherein the shock absorber comprises a layer of wood towards the attack side and a layer of polystyrene towards the non-attack side.

14. The security door of claim 3, wherein the layer of wood comprised in the shock absorber comprises pressure-treated plywood.

15. The security door of any preceding claim, wherein the defensive cassette comprises at least two layers arranged successively between the attack side and the non-attack side.

16. The security door of claim 15, wherein the defensive cassette layers comprise:

a wood layer towards the attack side;

a fibre composite layer towards the non-attack side; and a ceramic layer sandwiched between the wood layer and the fibre composite layer.

17. The security door of claim 16, wherein the defensive cassette wood layer comprises plywood.

18. The security door of either of claims 16 or 17, wherein the fibre composite layer comprises glass reinforced plastic (GRP).

19. The security door of any of claims 16 to 18, wherein the ceramic layer comprises aluminium(lll) oxide (AI2O3).

20. The security door of any of claims 16 to 19, wherein the ceramic layer is at least 3 mm thick, preferably at least 4 mm thick.

21. The security door of any of claims 16 to 20, wherein the ceramic layer is formed of at least two sub-layers of ceramic tiles, arranged with the tile patterns offset so that the boundaries between tiles in one sub-layer do not align with the boundaries between tiles in any sub-layer adjacent to that sub-layer.

22. The security door of any of claims 15 to 21, wherein the defensive cassette layers are adhered to one another using an elastomeric adhesive.

23. The security door of any preceding claim, wherein the front panel comprises steel.

24. The security door of any preceding claim, wherein the back panel comprises steel.

25. A replacement defensive cassette configured for substituting the defensive cassette of the security door of any preceding claim.

26. A security door system comprising the security door of any of claims 1 to 24, and the corresponding doorframe.

27. A method of improving the attack resistance of a security door according to any of claims 1 to 24, the method comprising:

removing the back panel; removing the defensive cassette;

substituting the defensive cassette with a replacement defensive cassette having an improved attack resistance with respect to the previous defensive cassette; and replacing the back panel.

28. The method of claim 27 as dependent on claim 5, wherein: removing the defensive cassette comprises:

removing the defensive cassette central panel, then removing the defensive cassette frame; and substituting the defensive cassette with a replacement defensive cassette comprises:

installing a replacement defensive cassette frame, then plugging a replacement defensive cassette central panel into the replacement defensive cassette frame.

29. The method of either of claims 27 or 28, further comprising:

prior to removing the back panel, removing one or more lock components from the non-attack face; and subsequent to replacing the back panel, replacing the one or more lock components.

30. The method of any of claims 27 to 29 as dependent on claim 12, further comprising:

between removing the back panel and removing the defensive cassette, removing the shock absorber; and between substituting the defensive cassette and replacing the back panel, replacing the shock absorber.

Intellectual

Property

Office

Application No: Claims searched: