GB2491185A

GB2491185A - One way door system

Info

Publication number: GB2491185A
Application number: GB1108968.7A
Authority: GB
Inventors: Bryan Michael Donovan
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-05-27
Filing date: 2011-05-27
Publication date: 2012-11-28
Also published as: WO2012164249A1; GB201322153D0; GB2505822A; GB2505822B; GB201108968D0

Abstract

A one way security door system for controlling egress of a user along a path between an entrance 14 and an exit 15. A plurality of moveable door panels 20, 22, 24 are moveable along a forward path between the entrance and exit defined by first pair of surfaces 10, 26. The door panels are also moveable in a return path between the exit and entrance defined by a second pair of surfaces 26, 12. A moveable restricting mechanism prevents access by a user by a user along the return. At least one door panel in the forward path prevents a user moving beyond the door panel at any one time. The restricting mechanism may comprise a retractable barrier 102 blocking the return path or the presence of a door may simply block the return path. The door panels may be driven along an orbital track where they slide along the passage in the forward direction and pivot at the exit and slide along the preferably narrow return path which is equal to the thickness of the door. Rather than sliding in the forward direction the doors may pivot about a post (65, fig.6b)

Description

Door System

FIELD OF THE INVENTION

This invention relates to one way door systems, in particular to door systems designed as entry/exit points addressing the problems of safety and security.

BACKGROUND TO THE INVENTION

Many types of door systems for controlling unauthorised access are known to exist.

Some, such as emergency doors with a "push bar to open" system do not prevent unauthorised access to a building or secure area if someone should open the door from within the building. An alarm may be raised, but it may have already been too late to prevent the unauthorised access. In some situations, this may lead the building proprietor to lock such emergency doors, leading to a potential health and safety risk.

In other door systems, some revolving door variants permit pedestrians to move through the door in only one direction, If a person is detected entering from the incorrect direction, the revolving door will stop, preventing unauthorised access to a restricted zone. The downside is that other users of the door system are prevented from passing through from the restricted zone in the permitted direction.

Many such door systems are designed to permit only one person at a time to pass through the door; accordingly problems are faced when coping with high volumes of traffic. In environments such as stadiums, airports and the like, to cope with high volumes of traffic a security guard may instead be posted on an exit to ensure pedestrians only pass through a security gate in the permitted direction.

Furthermore, many existing systems are unable to cope with other forms of traffic, such as vehicular traffic.

There is therefore a need for an improved door system to address the above problems.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a one way security door system for restricting movement of a user along a path between an entrance and an exit] the door system comprising: a pair of first surfaces defining a forward path between an entrance and an exit; a pair of second surfaces defining a return path between the exit and entrance; a plurality of moveable door panels moveable in the forward path between the entrance and exit, and moveable in the return path between the exit and entrance; and a restricting mechanism moveable between the pair of second surfaces to restrict access along the return path to a user; wherein at least one door panel extends between the pair of first surfaces in the forward path to prevent a user moving beyond the door panel at any one time, and wherein a door panel is configured to open to permit access beyond the door panel upon reaching the exit.

The door system may be used to control the flow of people, or may even be used to control the flow of vehicles] for example in car park entrance/exit.

This entry/exit point' design addresses problems in the areas of Safety and Security: * The locking of emergency exits (in order to prevent unauthorised access) * Ensuring uninterrupted egress whilst preventing access (pedestrian, vehicular or goods) The airlock can also be utilised for areas where access is permitted but exiting is forbidden such as parts of prisons, zoos (and other locations). It can also be utilised in areas where there is a need to keep people, animals or items within a compound whilst allowing free flow into the area.

Further use can be applied to areas in industry where a segregation of clean-air, temperature or pressure differential environment needs to be maintained for the movement of people, items or gasses. This is achieved by having airtight seals on all door movements.

This door system also provides a natural fire break' to segregate areas such as airport baggage belt systems and other locations, where the free flow of items in one direction is required whilst inhibiting the spread of fire and reducing the wind-tunnel' effect of access points between areas.

The one way door system comprises doors moveable along a pathway from an entrance to an exit, The doors extend between surfaces to prevent anyone getting past in either direction. Once at the end of the passageway, the door is returnable to the entrance end along a separate return path. The return path is arranged to prevent anyone returning to the entrance end via the return path by use of a restricting mechanism. This may be by virtue of a door panel moving along the return path blocking access to a user, i.e. a door panel itself provides the restricting mechanism.

Alternatively a restriction panel! closure mechanism may open/close to allow only a door panel to pass through. The doors are arranged in the door system such that one is always in the forward path -this ensures that no access to the entrance from the exit end of the pathway is possible at any time.

The door panels used in such a system may be glass, wood, metal, plastic or combinations thereof. The door panels may be solid, or alternatively may also be a mesh like structure. It will be appreciated however that, depending on the particular application, it may be necessary to use solid doors to restrict the passing of objects through a mesh type door.

In some door systems, it may also be necessary for the door panels to extend to the floor and/or ceiling, with the height of the door panel being sufficient to prevent unauthorised access by jumping over, or crawling under the door panels. However in some systems, such as for control of vehicle flow, this may not always be necessary.

The door system may further comprise a drive system to drive the plurality of moveable door panels along the forward path and then the return path back to the entrance. In other words, the door system is motorised using a drive system.

Alternatively the door panels may be moved by a user pushing on one of the door panels in the forward path. By coupling the door panels together via a linkage, pushing on a door in a forward path causes a door panel in the return path to move.

The restricting mechanism may comprise a closure mechanism, the closure mechanism moveable between an open position and a closed position; wherein in the open position, the closure mechanism enables access along the return path, and wherein in the closed position, the closure mechanism prevents access along the return path. The closure mechanism may also be biased closed such that it may need to be forceably opened to allow a door panel to move along the return path.

Responsive to one of the door panels approaching the closure mechanism, the closure mechanism may open to permit the door panel to move past the closure mechanism.

This may be via electrical communication with the closure mechanism, via a mechanical linkage (such as interacting with a lever coupled to the closure mechanism), or by direct contact between a door panel and the closure mechanism for

example.

The distance between the pair of second surfaces (forming the return path) may be less than a width of the door panels, i.e. the return path may be narrower than a width of the door panels. The door panels may move edge first along the return path for example to provide a more efficient use of space. Furthermore, it may also allow for implementation of a narrow return path, only as wide as the depth of a door panel to restrict access along the return path to a user.

In some embodiments at least two of the plurality of door panels may extend between the pair of first surfaces in the forward path to form an enclosure such that when in use a user of said door system located between the at least two door panels is prevented from moving beyond a first of the door panels to the exit and beyond a second of the door panels to the entrance.

In other words, two door panels may be used to form an airlock' to control the flow of users. With a door panel behind and in front of users in the forward path, the door system allows for crown control, limiting the capacity of users in any particular regions of the forward path at any one time.

Furthermore, the at least two door panels may be simultaneously moveable along the forward path to maintain the enclosure. This creates a rolling airlock that controls the rate of movement of users from the entrance to the exit of the door system. Additional door panels may also be added to create multiple airlock pockets' or enclosures.

The drive system may comprise a drive track which is arranged within the door system to define a path of movement for the door panels along the forward path and the return path. Such a drive system may use a chain drive or belt drive for example.

The drive system may be located above the door panels to ensure mechanical elements are away from users of the system.

The door system may further comprise a door guide. The door guide may be configured to define a rotational position of each of the plurality of moveable door panels in the one way security door system, and thus controls the direction each of the door panels faces at any position along the forward and return paths. One or more guides may be used, for example to allow the door panels to move along the return path sideways (edge first), then rotate to extend across the forward path to restrict access past the door panels.

In some embodiments the restricting mechanism may be coupled to one or more of the door panels such that the movement of the restricting mechanism (closure mechanism for example) is directly controlled and dependent on the position of one or more of the door panels. In such systems, the restricting mechanism may be moveable to maintain the coupling to the one or more of the door panels. For example, if the door panels rotate about a central column surface, the restricting mechanism may need to reciprocate.

According to a second aspect of the invention there is provided a method of operating a one way security door system the door system comprising: a pair of first surfaces defining a forward path between an entrance and an exit; a pair of second surfaces defining a return path between the exit and entrance; a plurality of moveable door panels; and a restricting mechanism to restrict access along the return path to a user; the method comprising: moving the door panels along the forward path between the entrance and exit; moving the restricting mechanism to permit to allow the door panels access along the return path; and moving the door panels along the return path between the exit and entrance; wherein at least one door panel extends between the pair of first surfaces in the forward path to prevent a user moving beyond the door panel at any one time, and wherein a door panel is configured to open to permit access beyond the door panel upon reaching the exit.

The restricting mechanism is moveable between the pair of second surfaces (such as surfaces of walls for example) to only allow door panels to access the return path. A door panel itself, moving along the return path may also provide the restricting mechanism by virtue of blocking the return path. Alternatively a closure mechanism may move to prevent access to (or within, or out of)the return path.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will now be further described, by way of example only, with reference to the accompanying figures in which: Figure 1 shows a first arrangement of the door system; Figures 2a-2c show the door system of Figure 1 in different positions; Figure 3 shows the guide rails of the door system in Figure 1; Figures 4a-4d show the guide rail and drive mechanism for the door system of Figure 1; Figure 5 shows a second arrangement of the door system; Figures 6a-6c show the door system of Figure 5 in different positions; Figures 7a-7b show another arrangement of the door system and the arrangement in different positions; Figures 8a-8b show an example use of the door system of Figure 1 used to control crowd flow towards a staircase; Figure 9 shows a combined door guide and propulsion track; Figure 10 shows the door rod of Figure 9; Figure 11 shows components of a door leaf assembly; Figure 12 shows a path of the door rods in the door guide; Figure 13 shows a closure mechanism used to provide a barrier to the restricted zone; and Figure 14 shows another arrangement of the door system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to Figure 1, this shows an arrangement of the door system 1 using moving door panels 20, 22, 24. Two outer surfaces 10, 12 form a pathway having an entrance end 14 and an exit end 15 in which the door panels move. Typically the entrance end would be from a restricted zone (shaded region) to which people would only be allowed to exit from along this pathway.

Surface 26 is used to partition the pathway into two pathways: a forward path and a return path. The forward path typically occupies a substantial portion of the width of the overall pathway in order to provide as much space as possible for crowds of pedestrians to move from the restricted zone (path entrance) to the non-restricted zone (path exit) An emergency exit door 18 may be located along outer surface 10 to comply with safety requirements (for example power failures, door faults), allowing pedestrians to return to the restricted zone/entrance end 14 should a power failure or fault stop the door system operating. In alternative arrangements, an emergency exit door may direct pedestrians to an alternative exit route should there be a need to rapidly empty the door system. It will be appreciated however that in such a configuration it may be desirable to prevent users returning to the restricted zone, i.e. still allowing movement in only the one direction. The exit routes provided by such an emergency exit door may be determined by the installer depending on the necessary security and health and safety requirements of the particular building.

Referring now to Figures 2a-2c, these figures show the motion of the door panels through the pathway.

In Figure 2a, two of the doors 20,22 form an enclosed space that progress towards the exit end in the forward path. An enclosure, or rolling airlock' is formed that guides the flow of pedestrians (or vehicular traffic), thereby ensuring a continuous flow for egress.

This mitigates against crushing accidents (i.e. controlling crowd flow), whilst maintaining integrity of the restricted zone 14. A third door 24 moves along a return path towards the entrance end 14. In such an arrangement the door panels may be synchronised (or position appropriately along the door movement path) to ensure there is never any direct access from the exit end/unrestricted zone back to the entrance end/restricted zone. I.e. this ensures that at least one door panel extends between the surfaces/walls in the forward pathway at any one time.

When moving along the forward path towards the exit end, the door panels 20, 22 extend to cover a sufficient width of the forward path to prevent access past the door, in either direction -i.e. the width of the door panels is sufficient to prevent access past the door. A seal, or flexible element, may be included on one or more sides of the door panel opposing the outer wall surface 10 and inner wall surface 26 to provide a seal to prevent items being passed into the restricted area. Alternatively, the sides of the door panel may be shaped to fit into corresponding channels on the surfaces, thereby preventing access. In its simplest form, the door panel may be of sufficient width to be a snug fit between surfaces 10 and 26 in the forward path to prevent access past the moving door panel. In other variants the door panel may comprise bars extending towards the wall surfaces to prevent a user moving past the door; however, it will be appreciated that such a variant may not prevent a user passing items between the bars. In some environments therefore, such a variant may not be appropriate.

The return path, between inner wall surface 26 and outer wall surface 12 provides a return route for the door panels and typically only needs to be of sufficient width to accommodate the door panel thickness/depth. If the return path width is only just wide enough to accommodate the door panel thickness, then any door moving from the exit end to the start end will prevent anything else, in particular a user, using the return path to return to the entrance end/restricted zone -thus the narrow pathway and the door itself acts as a restricting mechanism. The path may be too thin to prevent a user accessing it. Furthermore, a door panel returning to the entrance also blocks access through the return path to users. Thus the return path, by its construction, acts to inhibit access to the restricted zone. It will be appreciated however that in some alternative arrangements an installer may wish the return path/region to be larger to enable access for servicing of the door system. Therefore, as shown in Figures 2a-2c, additionally, or alternatively, a closure mechanism may also be used to act as an inhibitor for the return path.

Referring now to Figure 2b, the second door, i.e. the trailing door panel 20 at the rear of the airlock secures the restricted zone/entrance 14. The first door, i.e. the leading door 22 can then open the airlock and provide access to the non-restricted zone or exit 15. Door 22 rotates until it aligns with the return path, and then, in Figure 2c, slides back through the return passageway to become a subsequent trailing door to leading door 24.

The return path may be protected by a closure mechanism 102. This closure mechanism located on or in outer surface 12, is biased shut to cover one end of the return region to prevent access to the return path. It will be appreciated however that it may be present anywhere along the return path. The closure mechanism only needs to open when a door panel needs to pass through.

In the arrangement shown in Figures 2a.-2c three door panels are used. Panels may be positioned along a drive system (comprising a propulsion track/guide system) to propel the door panels along the pathways.

In alternative arrangements more panels may be used, which would allow the forward path to be subdivided into multiple forward moving regions, if it were desirable to divide up the flow of traffic further.

Referring back to Figure 1, a drive system 16 provides propulsion for the door panels.

Typically this may be a chain or belt drive type of system to which the door panels can be mounted. The drive system may be mounted to either the floor or ceiling of the passageway. In the embodiment shown in Figure 1 the drive system is fitted to the ceiling to eliminate the presence of any tripping hazards for users of the passageway.

With the drive system mounted on or in the ceiling, the drive system is arranged to form a pathway for the door panels. In Figure 1, only a single drive system is used providing one connected to each door panel, although in alternative arrangements, multiple chain or belt drives may be used for example.

In environments with particularly high ceilings, the drive system may still be installed above the doors at a lower level using a dedicated framework for the drive system and any guide rails.

Figure 3 shows guide rail 30 installed on the pathway ceiling. These rails may not be powered, instead being used to eliminate any undesired rotational movement of door panels moving along the forward path, thereby maintaining a tight seal to the walls 10,26 and improving robustness. The door panels comprise guide rail Fugs 32,34,36,38,40,42 to engage with one or more of these guide rails.

Figures 4a-4d show the guide rail and drive mechanism for the door system of Figure 1. The figures also show how a leading door (such as door 22 at the front of the rolling airlock in Figure 2a) returns along the return path to become a trailing door (door 20 at the end of the rolling airlock in Figure 2a).

The complete path of the drive system 16 is shown in shown in Figure 4a. The full path is not shown in Figures 4b-4d for clarity.

As door panel 24 completes its return along the return path to the entrance of the passageway (Figure 4b), the door panel begins to rotate about drive element 50 as it moves into the forward path (Figure 4c). The guide rail element 36 mounted to the trailing end of the door panel engages with guide rail 30 as the door moves back into the forward path (Figure 4d). Further guide rail elements 32,3638!40,42 are also shown on door panels in Figure 3 and may be used to provide additional connections to one or more other guide rails.

Further details of the door/drive/guide mounting are shown in Figures 9-12.

The example embodiment shown in Figure 1 and Figures 2a-2c uses three door panels. Alternatively, only two door panels may be used. Such an arrangement however may require a more complex drive system, with variable gearing or independent motion control for each door to ensure that a door panel returning to the entrance end 14 along the return path reaches the entrance end before the other door reaches the end of the forward path.

Further example of two door panel systems are also described herein.

Figure 5 shows a second arrangement of the door system! known as the half-curve' exit system. One outer surface 61 is curved, and the inner partition wall surface 65 is formed from column 65. In this arrangement, the forward path is curved, with the doors moving through this region in a rotational manner, maintaining connection (to prevent access to the restricted zone 80) with the outer surface 61 and inner surface on column using any of the approaches previously described.

In this arrangement the inner surface is formed on a column structure, with the return path below the column and outer surface 63.

Figures 6a-6c show the movement of the door panels of Figure 5. The process operates as shown in Figures 2a-2c, with doors moving from the entrance to the exit along the forward path. The doors then return via the return path to the entrance end of the passageway. A closure mechanism 102 is again used here to close any gap remaining when no door is moving along the return path.

The drive system 66 and guide rails 70 (showing in Figure 5) are also modified in this arrangement to map to the different path of the door panels.

Figures 7a and 7b show a right angled implementation of the door system. A minimum of two door panels 96,98 are used in this arrangement. The door panels move along the forward path around inner wall surface 95 using drive system 94. The return path to return the door panels back to the entrance of the passageway has a closure mechanism 102 to close any gap remaining between outer surface 93 and inner surface 95. An emergency exit door 100 is again also provided along outer wall 91.

Figures 8a and 8b show a side on view and top down view of the embodiment shown in Figure 1. The rolling airlock is installed before a stair case or escalator to avoid overcrowding accidents by controlling the rate of flow of pedestrians. If an emergency stop button is activated, the doors stop and remain closed so as to protect the restricted zone (shaded region in Figure 8b). This prevents against a toppling dominoes' effect of people falling on top of others. The emergency door 18 then opens allowing pedestrians to return to the restricted zone.

Figure 9 shows further details of the door guide and drive system. In the example shown in Figure 9, the same connection may be used to provide both guidance and drive, although it will be appreciated that these may also be separable.

Mounted to the ceiling 120, the drive system 122 is engageable with a drive element 50, the drive element being mounted into guide element 32 having a guide lug 131. A drive retainer 124 then locks the drive element into place on the drive system. The drive system 122 may comprise a chain-drive, belt drive or other propulsion method.

The guide element 32 (shown in more detail in Figure 10) comprises a guide lug 131 and guide member 133. The guide lug 131 engages with door guide 126 and is held into place with guide retainer 128.

S

The guide element is rigidly fixed to the door panel 60 such that when the guide element rotates1 the door panel correspondingly rotates. By contrast, the guide element and door may rotate freely with respect to the drive element. This allows the door to rotate independent to its direction of movement relative to the drive system -each door panel can then rotate within the one-way security door system according to the guide system. Referring to door panel 98 in Figures 7a and 7b for example, it can be seen in Figure 7a that door panel 98 is substantially perpendicular to the drive system. In figure 7b however, the door panel 98 now moves parallel to the drive system along the return path.

Figure 10 shows an illustration of an elongated/oval guide lug 131 that allows the positioning of the guide element relative to the drive system to be adjusted. Figure 12 also shows how the guide track varies in width to allow the guide element to rotate.

Control of the rotation may also be controlled by varying the positioning of guide tracks relative to one another so that the door panels are angled as required.

It is not necessary for the ceiling to carry the full weight of the doors. Figure 11 shows for example, how universal wheels may be fixed to the base of the doors, to allow the doors to roll in any direction over the ground.

Figure 13a and 13b show a closure mechanism 102 used to provide a barrier to the restricted zone. This closure mechanism is biased shut to cover one end of the return path to prevent items being passed between the restricted zone/entrance and unrestricted zone/exit of the door system. The automatic closure system may be forceably pushed out of the way by a door panel 60 as the door moves into the return path (Figure 13b). Alternatively, more complex release mechanisms may be implemented comprising mechanical linkages to the door panels/drive/guide rails such that the closure mechanism only releases as a door approaches. Electronic detection systems may also be used, comprising sensors and/or communication finks between the release mechanism and moving doors.

Figure 14 shows another variation to the door system. Fn this arrangement two door panels 142, 144 rotate about a central column 143 that provides the inner surface. The forward path is formed from the outer wall 140 and the column/wall 143. To maintain one way access, the door panels rotate flush to the curved portion of outer wall 140.

The guide rail 146 is fitted to the door panels in Figure 14.

A return path is formed from the surface of column/wall 143 and end of wall surface 141 facing surface 143, through which each door passes to return to the entrance of the forward path.

A closure mechanism to restrict access via the return path is mounted to, or within, outer wall 141. Coupled to the closure mechanism is a guide element 147. The guide element 147 engages with the guide rail on the door panels, causing the closure mechanism to reciprocate as the door panels rotate to ensure no user can access the return path.

Further door panels may also be added, and will also rotate about central column 143.

The guide track will then be linked to the additional doors. An emergency exit door 150 may also be provided if more than two doors are used as a rolling airlock will be formed, blocked access to the exit end and entrance end if the doors should stop rotating.

No doubt many other effective alternatives will occur to the skilled person. It will be understood that the invention is not limited to the described embodiments and encompasses modifications apparent to those skilled in the art lying within the spirit and scope of the claims appended hereto.

Claims

CLAI MS: 1. A one way security door system for restricting movement of a user along a path between an entrance and an exit, the door system comprising: a pair of first surfaces defining a forward path between an entrance and an exit; a pair of second surfaces defining a return path between the exit and entrance; a plurality of moveable door panels moveable in the forward path between the entrance and exit, and moveable in the return path between the exit and entrance; and a restricting mechanism moveable between the pair of second surfaces to restrict access along the return path to a user; wherein at least one door panel extends between the pair of first surfaces in the forward path to prevent a user moving beyond the door panel at any one time, and wherein a door panel is configured to open to permit access beyond the door panel upon reaching the exit.
2. A one way security door system as claimed in claim 1, further comprising a drive system to drive the plurality of moveable door panels along the forward path and then the return path back to the entrance.
3. A one way security door system as claimed in claim I or claim 2, wherein said restricting mechanism comprises one of the door panels.
4. A one way security door system as claimed in any preceding claim, wherein the restricting mechanism comprises a closure mechanism, the closure mechanism moveable between an open position and a closed position; wherein in the open position, the closure mechanism enables access along the return path, and wherein in the closed position, the closure mechanism prevents access along the return path.
5. A one way security door system as claimed in claim 5, wherein the closure mechanism is biased closed.
6. A one way security door system as claimed in claim 4 or 5, wherein responsive to one of the door panels approaching the closure mechanism, the closure mechanism is configured to open to permit the door panel to move past the closure mechanism.
7. A one way security door system as claimed in any preceding claim, wherein the distance between the pair of second surfaces is less than a width of the door panels.
8. A one way security door system as claimed in any preceding claim, wherein the distance between the pair of second surfaces substantially corresponds to a depth of a door panel.
9. A one way security door system as claimed in any preceding claim, wherein at least two of the plurality of door panels extend between the pair of first surfaces in the forward path to form an enclosure, such that when in use a user of said door system located between the at least two door panels is prevented from moving beyond a first of the door panels to the exit and beyond a second of the door panels to the entrance.
10. A one way security door system as claimed in claim 9, wherein the at least two door panels are simultaneously moveable along the forward path to maintain the enclosure.
11. A one way security door system as claimed in claim 9 or I U, wherein a third of the door panels is located along the return path when the at least two doors are positioned in said forward path.
12. A one way security door system as claimed in any one of claims 2 to 11, wherein the drive system comprises a drive track, wherein the drive track arranged to define a path of movement for the door panels along the forward path and the return path.
13. A one way security door system as claimed in claim 12, wherein the drive system comprises a chain-drive.
14. A one way security door system as claimed in claim 12 or 13, wherein the drive system is located above the door panels.
15. A one way security door system as claimed in any preceding claim, further comprising a door guide, the door guide configured to define a rotational position of each of the plurality of moveable door panels in the one way security door system.
16. A one way security door system as claimed in any preceding claim, wherein the restricting mechanism is coupled to one or more of the door panels.
17. A one way security door system as claimed in claim 16, wherein the restricting mechanism is moveable to maintain the coupling to the one or more of the door panels.
18. A one way security door system as claimed in any preceding claim, further comprising an emergency exit door located on one of the pair of first surfaces.
19. A one way security door system as claimed in claim 1, wherein in use, the door panels are moveable by a user of the one way security door system.
20. A method of operating a one way security door system the door system comprising: a pair of first surfaces defining a forward path between an entrance and an exit; a pair of second surfaces defining a return path between the exit and entrance; a plurality of moveable door panels; and a restricting mechanism to restrict access along the return path to a user; the method comprising: moving the door panels along the forward path between the entrance and exit; moving the restricting mechanism to permit to allow the door panels access along the return path; and moving the door panels along the return path between the exit and entrance; wherein at least one door panel extends between the pair of first surfaces in the forward path to prevent a user moving beyond the door panel at any one time, and wherein a door panel is configured to open to permit access beyond the door panel upon reaching the exit.
21. A one way security door system substantially as herein described with reference to one or more of the accompanying drawings.