GB2175344A - Security door closure - Google Patents

Abstract

A security door closure comprises a steel or like door (10) which is received into a reinforced door opening (14) to close therein with compression of a seal (26, 28). The door locks closed by means of bolts (34) which are driven into keeps (36) on the frame of the door opening by hydraulically controlled rams (38). The bolts and the keeps are mutually shaped so that, as the bolts are driven home, the hinges (12) on which the door is mounted permit a terminal closing movement of the door which compresses the seal to ensure a gas/air tight closure able to withstand a pressure differential from either side of the door. <IMAGE>

Description

SPECIFICATION Security door closure This invention relates to a security door closure, more especially a door closure for use in securing sensitive areas in any of a variety of fields, such as research establishments, defence establishments including shelters in the event of warfare, chemical processing plants, banks and other high security establishments, bullion vehicles and the like, ships, and submarines. Moreover, although the term "door closure" is employed generically, the invention is intended also to cover hatch closures, window closures and other situations where an access opening is to be closable in a secure manner with the environment on one side of the opening shielded from the environment on the other side.

Known security doors for providing secure closure of an area are generally locked in a closed position by mechanically driven bolts which are carried on (or in) the door and are driven by the turning of a handle into keeps on (or in) the door frame. Such doors are gas and air tight and offer some security against pressure differentials and shock waves due to blast. Such doors generally are relatively small and if manufactured to a large size it can become difficult for the door to be securely locked in a closed position.

The present invention aims to provide a security door which offers a higher degree of gas/air sealing and/or pressure differential and/or blast protection to a sensitive area protected by the door than has been available hitherto.

According to the invention, there is provided a security door closure wherein a compressible seal is provided on the door frame and/or the door, and the door is lockable in the closed position by at least one bolt which is driven into the locking position by an hydraulically operable control means, the door being so mounted that the locking movement of the bolt or bolts effects a terminal closing movement of the door for compressing the seal into a gas/air tight condition.

Embodiments of the present invention will now be described with reference to the accompanying drawings in which: Figure 1 is an elevation view, partially exposed, of a gas tight door embodying the present invention, Figure 2 is an enlarged sectional view on the line Il-Il of Figure 1, with the door closed, Figure 3 is a view of a hinge of the door shown in Figure 1, Figure 4 is a layout view of a blast proof door embodying the present invention, Figure 5 is an enlarged view on the line V-V of Figure 4, Figure 6 is an enlarged view on the line VIl-VIl of Figure 4 showing a door bolt actuating mechanism, and Figure 7 is an enlarged view on the line VI--VI of Figure 4 and in particular illustrating the door frame.The arrangement embodying the invention as shown in Figures 1 to 3 includes a door 10 hinged at 12 to side door frames 14. Each hinge 12 has pivot parts 16 and 18 linked by a part 20 as shown. The part 20 is rotatable about the part 16 and the door 10 rotatable about the part 18 in such a way as to enable the door to close flat onto the face of the door frame 14. The face of the door incorporates a seal 22 located in a recess 24 running around the door frame as shown. The seal is in two parts, a primary part 26 shaped as shown and a secondary part 28 received in the primary part. The leading edge of the part 28, as the door closes, bears on a strip 30 formed on the face of the door frame 14.

The primary seal 26 is, as noted, housed in a fabricated channel welded to the door leaf.

This seal is of good quality rubber (Neoprene 60/70 quality to British Standard 4255). The secondary seal which is received in the primary seal is of good quality Neoprene rubber 15/55 specifically designed for ease of removal and replacement if required.

When the door is in the closed position the secondary seal leading edge comes into contact with the strip 30 and is brought into tighter pressure contact with that strip as the bolts of the door (to be described below) are pushed into the door keeps.

The door 10 incorporates a window 32 as shown. This window is of double 9mm bandit proof glass, 33mm bullet resistance material or single 9mm bandit glass fitted to either one side or the centre of the aperture formed in the door itself. The window frame 33 is fixed to the door as shown.

When the door has been moved to a closing position (Figure 2) it is finally locked by moving bolts 34 into keeps 36. Each bolt 34 is moved out of the door and into the keep by an hydraulically operated ram 38. A spring 40 is provided, as shown, tending to urge the bolt into an open position (that is to say spring 40 acts against the operation of the ram when the ram is activated). The ram 38 is mounted as shown, within the door 10, and bears on the end of the bolt 34. The outermost end of the bolt 34 is shaped as shown to cooperate with a bevelled inlet to the keep 36. When operated the ram 38 drives the bolt 34 into the keep 36 and the camming action of the leading edge of the bolt on the bevelled inlet to the keep pulls the door 10 down on to the strip 30 by compression of the seal 22. The design provides that the seal compresses by up to 3mm.

The rear end of the keep (that distant from the door) includes a microswitch 44 operable to give an output signal when the bolt 34 has been fully driven into the keep.

Hydraulic pressure for the rams 38 is provided by a pump 46 hand driven by a wheel 48. The design provides that the pump 46 is operated fully by one turn of the wheel 48.

Solenoids 50 are actuable to interrupt the supply of hydraulic fluid from the pump 46 to the rams 38, for a period of time determined by a timer (not shown). Thus, the door closing operation provides that first the door is moved to the position shown in Figure 2, the hand wheel 48 is then turned, through one revolution, to operate the pump and drive the bolts into the keeps fixed on the door frame back plate. The closure of each of the bolts is monitored by the microswitches and, when each of the switches gives an output, then the door is fully locked. At this time the solenoid valve 50 is actuated and locks the oil in the hydraulic system in the position which it has reached, thereby ensuring that the bolts cannot be removed from the keeps until the solenoid is de-energised (under the control of the timer).On opening the door the situation is reversed; the solenoid valve will automatically lock the oil in the hydraulic system with the bolts 34 in the open position, thereby eliminating the possibility of the bolts being moved to a locking position whilst the door is open (preventing the door from being closed). The solenoid is of a type which fails safe, that is to say, it fails to a locked position and when the current to the solenoid is interrupted the solenoid will fail to a safe position.

Power to the solenoid valve included in the door, and to other equipment provided in the arrangement, may be supplied to the door via a dummy hinge (not shown).

For safety in case of power failure a manually operable override is provided which is accessed by means of a removable plate (52) adjacent the solenoid valve 50, allowing the solenoid to be operated from the safe and/or clean side of the door installation.

The hydraulic hand pump provided in the arrangement is a sealed unit.

Removable panels 53 are provided adjacent the position of the bolts in the door leaf 54.

The door and frame may be manufactured in mild steel 14 gauge to BS 1449CR4 and suitably braced with four 6mm stiffeners. The door leaf is of welded and bolted construction with an 8" X 12" bandit proof glass window fitted to the outer and inner skin of the door leaf. The panels for the windows are held in position with securing plates and suitable gaskets. The door leaf is supported on the double hinges shown in detail in Figure 3, each hinge having the double action allowing the door to close with the minimum effort and generally flat onto the back plate. More generally, the door may be made of stainless steel and/or mild steel, with stainless mild steel clad surfaces.

The back plate, against which the door closes, may be of 12mm mild steel plate BS4360 Grade 43A which has been flame cut, stress relieved and finished to the desired requirement. The strip 30 on the back plate generally comprises a 25 X 15mm bright mild steel flat forming part of the seal. This is of bolted construction with counter sunk screws at 75mm spacing. This section is installed with a gasket suitable to withstand any chemical agents which may be used in an attempt to gain access to the secure area protected by the door and forms an air/gas tight joint.

In addition to forming a gas/air tight closure, the door is able to withstand pressure from either side up to at least 15cm water gauge, and maintain this pressure under shock waves emanating from extreme gravitational forces.

Although the above-described door is not specifically designed to withstand direct blast, it is designed to withstand the gravitational forces resulting from blast and gravitational force vibrations transferred through the building structure to the door installation.

Although described above as making use of four hydraulic lock bolts it will be appreciated that the number and positioning of the lock bolts may be varied. For example it is possible that the locking of the door may be achieved by two point or possibly even one point locking on the opposite side of the door from the hinges. With four point locking (two on the hinge side and two on the other side as described above), all four point locking bolts are arranged to pass through the two side edges of the door.

Other variations which may be made to the arrangement so far described provide that an electrical lock is located at the top of the door, operable to keep the door in a locked position for a specific time (as set for example on a time interlock panel located adjacent the door). Such an arrangement may be operated to retain the door in a locked position, after the handle has been operated to open the door until the predetermined time for which the door must be closed has elapsed.

Other modifications which may be made to the described arrangements provide, for example, that the hydraulically operable pump and door lock bolts may be provided in the frame of the doorway, the bolts being arranged to pass out of the door frame and into keeps formed as part of the door.

It is also envisaged that a door which is substantially as described with reference to Figures 1, 2 and 3 may be used as one part of a security arrangement either with another, similar, door or with doors as will be described below. It is envisaged that a timing mechanism may prevent the door from being opened for a minimum period of four to five minutes following its closure, which period may be considered sufficient to enable a person entering, for example, a "radioactively clean" area to be cleaned e.g. by washing, thereby preventing contamination of the clean area behind the door.

Figures 4 to 7 describe a blast door arrangement embodying the present invention, more especially intended for use in crisis control centres, civil defence centres and the like.

In these figures the exemplified door 100 comprises a concrete block 102 carrying a door skin 104, for example of mild steel splinter proof armoured plate and/or bullet resistant armoured plate. The block is approximately 25cm thick and the skin itself stands approximately 165mm proud of the "inner" surface of the concrete block 102. When the door 100 is in a closed position (Figure 6) the door skin fits within the aperture of the door frame whilst the concrete block overlies the aperture. The location of the door in a door frame is shown in Figure 5 by the chain dotted line 106.

The door houses an electrical pump and reservoir 108, hand pump 110, double-acting hydraulic rams 112, valving 114 (operable to control the flow of hydraulic fluid in hydraulic lines-not shown-coupling the pumps 108, 110 to the rams 112), door bolts 116 and header blocks 118. Control switches are provided at 120 on the inside of the door and 122 beneath a shroud 124 on the outside of the door. The switches 122, 124 control operation of certain of the valves 114' which are activated by solenoids. The outside of the door is provided with a handle 126 and the manual pump is operable by a detachable handle such as shown at 128.

Figure 6 illustrates in detail a bolt assembly in use in the door described in Figures 4 and 5. Each bolt assembly comprises a double acting ram 112 having ports 200, 202. Ram 112 is mounted in soft rubber bushes 204, 206 in a mounting block 208 and saddle 210, respectively as shown, within the door skin.

The ram is held to the mounting block 208 by a pin 212. The piston or rod 214 of the ram 112 enters the back of the door bolt 116 and is screwed and dowel-pinned into position.

Bolts 116 pass through a locating block 216 and the edge 218 of the door to enter a keep 220 when driven so to do. The leading end of the bolt 116 is bevelled as shown at 220 and the entrance to the keep 220 is also bevelled as shown at 224. The edge of the door frame adjacent the keep carries a seal 226 onto which the door closes.

Desirably the door frame (Figure 7) is reinforced by steel plates 228 coupled by welding to rags 230 in turn welded to an anchor bar 232. The hinges for the door are shown at 234 bolted to the concrete block 102 forming part of the door and to the plate 228 respectively as shown.

In the arrangement described with reference to Figures 4 to 7, the rams used for latching may be 15mm bore ram cylinders with a 10cm stroke operable with a maximum hydraulic pressure of 200 bar. Each cylinder is fixed to the bulk mechanism by the mounting bracket, rubber insert and securing pin as shown and the front end of a cylinder floats on the rubber insert in the saddle support.

The hydraulic electric pump is designed to fit into the 165mm thick door skin as shown in, particularly, Figure 5.

The electric motor for driving the pump is a totally enclosed fan, ventilated electric motor class F. This is coupled to a high quality pressure balanced gear pump with variable pressure direction piston operated relief valves.

The valves are normally preset at the time of assembly.

The oil reservoir is fitted with a sight level gauge (not shown) which provides an indicator for minimum safe working of oil levels. The reservoir may also be fitted with an audible and visual alarm if required.

Hand pumps provide that the door may be locked (or unlocked) should there be a power failure. If a power failure should occur, the oil by-pass valves are shut off and the twin hand pump is operated to move the bolts into the locked or unlocked position. As noted above the pump is fitted with a removable handle that may be stored adjacent the door.

The hydraulic pump reservoir will be situated at the bottom part of the door and piping from the pumps to the cylinders will be via two header blocks as shown.

Adjacent the pumping reservoir are located directional solenoid valves and solenoid locking valves which enable the door to be locked in an open (or-closed) position in substance in the same way as described above for the door disclosed in Figures 1 to 3.

As noted above, the top part of the door houses the push button switches which can be used to operate the electrically operable pump.

As described the pump may be mains electrical. However, it is also possible to make provision for it to be battery powered.

Again as described above with reference to Figures 1 to 3, the keeps may be provided with microswitches or other means operable to sense that the door is in a locked position which are operable to actuate solenoid valves interrupting the supply of hydraulic fluid to the double acting rams 112 and effectively locking the door in a closed position. In this way the retention of the door in a closed position is not dependent on the pressure in the hydraulic system, provided by the pumps, being maintained.

It will be appreciated that various modifications may be made to the arrangements described above with reference to Figures 4 to 7 without departing from the scope of the invention. More especially, it is feasible for the blast door of Figures 4 to 7 to be modified for manual operation of the hydraulic bolt control, for example as previously described with reference to Figures 1 to 3. It will further be appreciated that the particular arrangements above described provide a system in which a substantially higher degree of protection against the effects of blast is obtained than has heretofore been obtained with the known designs of security door. The ability to maintain a substantial pressure differential from either side also provides a substantial advance over most known designs of security door closure. In particular it will be appreciated that the arrangements provide that the door is securely mounted on the wall having the aperture to be closed; the door frame itself, which supports the door, being fabricated from heavy metal parts.

It is envisaged that such a door as is described with reference to Figures 4 to 7 will be provided as one of a pair of doors offering protection to a secure area against blast damage. If a plurality of such doors are provided, for example along a passageway, it is envisaged that a control system would be provided for ensuring that only one door could, at any time, be open, at least one door being at all times closed.

It will be appreciated that various other modifications may be made to the described arrangements without departing from the scope of the present invention as defined by the appended claims.

Claims (20)

1. A security door closure wherein a compressible seal is provided on the door frame and/or the door, and the door is lockable in the closed position by at least one bolt which is driven into the locking position by an hydraulically operable control means, the.door being so mounted that the locking movement of the bolt or bolts effects a terminal closing movement of the door for compressing the seal into a gas/air tight condition.

2. A closure according to claim 1, wherein the or each bolt is slidable into and out of a keep, the bolt and keep being relatively shaped to produce the terminal closing movement of the door as the bolt is driven deeper into the keep.

3. A closure according to claim 1 or claim 2, wherein the bolt or bolts are carried by the door.

4. A closure according to claim 3, wherein the hydraulic control means is incorporated within the door and acts on bolts emergent from the edge face of the door.

5. A closure according to any of claims 1 to 4, wherein the hydraulic control means comprises a ram hydraulically operable by a pump.

6. A closure according to claim 5, wherein the pump is manually operable by a hand wheel.

7. A closure according to claim 5, wherein the pump is operable by an electrical pump.

8. A closure according to claim 7, wherein the pump is also operable by an emergency manual pump.

9. A closure according to claim 5 or any claim appendant thereto, wherein the hydraulic control means includes a solenoid operable valve which is actuated by a bolt closure detector, thereby to maintain the bolt in the locking position when the hydraulic pressure provided by the pump is released.

10. A closure according to claim 9, wherein de-actuation of the valve is controlled by a timer.

11. A closure according to claim 9 or claim 10, wherein the valve also acts to lock the bolt in the retracted condition following bolt retraction to open the door.

12. A closure according to any of claims 9 to 11, wherein the solenoid valve fails to the locking condition in the event of a power failure.

13. A closure according to any of claims 9 to 12, wherein a manual override is provided for the solenoid valve.

14. A closure according to any of claims 1 to 13, also having an electrical lock controlled by a timer and acting to maintain the door in the closed condition for a timed period.

15. A closure according to any of claims 1 to 14, including a return spring for the or each bolt and acting to bias the bolt towards its retracted position.

16. A closure according to any of claims 1 to 15, wherein the seal comprises a primary rubber part and a replaceable secondary rubber part carried by the primary part.

17. A closure according to any of claims 1 to 16, wherein the door is made of armoured steel plate.

18. A closure according to any of claims 1 to 16, wherein the door is faced with mild steel plate.

19. A closure according to any of claims 1 to 18, wherein in the closed and locked condition of the door the seal is effective to enable pressurisation at either side of the door up to at least 15 cm water gauge.

20. A security door closure substantially as hereinbefore described with reference to Figures 1 to 3 or Figures 4 to 7 of the accompanying drawings.