GB2119011A - Door locking mechanisms for security enclosures - Google Patents

Abstract

In a strongroom door bolts connected to a drive strap 4 are thrown from the leading edge of the door by means of a crank pin 11 working in a drive slot 12 in the strap 4. Another drive strap 13 carrying top-edge bolts is driven from the strap 4 through a bell crank 18. When the bolts are thrown a first lock 24 shoots a locking bar 28 to block the crank pin 11. In this position the bar 28 both prevents rotation of the crank pin 11 in the withdrawing direction and counteracts end pressure on the strap 4 directly through the pin 11. A second lock pivots a locking member 32 so that a flange 32A blocks withdrawal of strap 4 and its top surface 32B blocks withdrawal of an abutment 34 welded to the strap 13. "Live" relockers (not shown) are also described, these block the retraction of straps 4 and 13 if the door is attacked in certain ways. <IMAGE>

Description

SPECIFICATION Door locking mechanisms for security enclosures The present invention relates to locking mechan ismsforthe doors of safes, vaults, strong rooms and the like security enclosures.

It is customaryforthe door of a strong room or the like enclosureto be locked by means ofboltsthrown from one or more ofthe door edges into engagement with the surrounding frame, for which purpose there is provided an externally-accessible handle orthe like operating member which drives the boltworkthrough a mechanical transmission mounted with the door, to throw orwithdrawthe bolts as required. This boltwork is in turn locked in its thrown condition bythe operation of one or more lockswhich may, for example, throwtheir bolts into engagement with portionsofthe main boltworkto resistforcible retraction thereof.

One aim ofthe present invention isto provide a door-locking mechanism generally ofthe nature indicated above which can achieve a secure locking function with economy in the number and complexity ofthe components involved.

Accordingly in one aspect the invention resides in a locking mechanism forthe door of a security enclosure which comprises: boltwork; a mechanical trans missionforthrowing and withdrawing the boltworkin responseto corresponding operation of an externallyaccessible operating member; and at least one lockfor selectively locking the boltwork in itsthrown condition; wherein the transmission includes a rotatable thrower having a projection engaging in a drive slot in a linearly-movable transmission member connected with bolts of said boltworkwhich arethrown from an edge of the door, whereby rotation of the thrower in either sense imparts linear motion to said transmission member in a corresponding sense to throw or withdrawthose bolts; and wherein a said lock is arranged to lock those bolts when intheirthrown condition by moving a locking member into a position in which it blocks movement of said projection in the sense of rotation thereof corresponding to withdrawal of those bolts and in the sense of linear motion of said transmission member corresponding to withdrawal of those bolts.

In a preferred embodiment of a locking mechanism in accordance with this aspect ofthe invention the boltwork includesfurther bolts thrown from an edge ofthedoorperpendiculartothefirst-mentioned edge, in which case there may be provided a further linearly-movable transmission member connected with said further bolts and linked to the first-mentioned transmission memberthrough a crank mechanism whereby linear motion ofthefirst-men- tioned transmission member in either sense to throw or withdraw thefirst-mentioned bolts is transmitted into linear motion ofthefurthertransmission member in a corresponding sense perpendicularly thereto to throw orwithdrawthe further bolts.Preferably in this case there is a lock in addition to the first-mentioned lock which is selectively operable to lock the boltwork in itsthrown condition by moving a locking member into a position in which it blocks the linear motion of both said transmission members in the respective senses corresponding to withdrawal ofthefirst- mentioned and further bolts.

The first-mentioned locking member may itself be arranged for linear movement into its locking position in which case it may conveniently be borne by means of a slot formed in the locking member engaging around a spindle by which the thrower is rotated and/or a pivot means of said crank mechanism.

In a second aspectthe invention is concerned with auxiliary locking systems or "relockers" as are frequently employed in the door-locking mechanisms of securityenclosuresto provide additional resistance to forced entry. A relocker typically comprises a locking member which is spring biased towards a position in which it blocks withdrawal of the door's boltwork, and which is controlled from a remote location within the door via a cord, wire orthe like flexible tension member.In a so-called "dead" relockerthe locking member is normally held away from its locking position by the tension in the cord orthe like but is permitted to move into its locking position under the spring bias when the tension is relieved eg by the severing or dislodgement of the cord orthe like, or the disintegration of a frangible orfusible elementto which it is anchored, as the result of a burglarious attack on the enclosure.In a so-called "live" relocker the flexible tension member is connected to a bolt of a primary lock so thatthe auxiliary locking member is normally engaged and released each time with the throwing and withdrawal ofthe primary lock bolt, but again if the tension is relieved in the cord or the like as the result of a burglarious attackthe locking member can remain in its locking position under the spring bias irrespective ofthe condition of the primary lock.

In this second aspectthe invention resides in a locking mechanism for the door of a secu rity enclosure comprising boltworkfor securing the door closed when thrown; one or more primary locks for selectively locking the boltwork in its thrown condition; and a relocker (live or dead) adapted to lock the boltwork in its thrown condition, independently ofthe state ofthe primary lock(s), in response to the detection of an attack upon the enclosure; the relocker including a pivotally-mounted locking member having a tapered nose which, in the locking position thereof, is arranged to engage with a movable transmission member by which said boltwork isthrown and withdrawn (eg the first-mentioned orfurthertransmission member in a locking mechanism according to the above-defined first aspect ofthe invention); and said nose of the locking member being so configured in relation to the pivotal axis thereof thatthe tendency of forced retraction ofthetransmission memberwhile the locking member is in its locking position is to urge the locking memberfurther in the sense of rotation in which it moves to its locking position.

In one convenient arrangement the locking member is borne by a post which passes through a slot in the transmission memberand thereby serves as a guide for the motion thereof, the nose of the locking member entering the same slotwhen in the locking position. These and other aspects of the invention will now be more particularly described, byway of example, with reference to the accompanying drawings, in which: Figure 1 shows the arrangement of a preferred door-locking mechanism according to the invention, in its unlocked condition; Figure 2 shows the mechanism of Figure 1 in its locked condition; Figure 3 shows the mechanism of Figure 2 with the addition of relocking components; Figure 4 is a section through the locking mechanism and associated doorstructure,taken on the line IV-IV of Figure 3; and Figure 5 shows to an enlarged scale a relocker incorporated in the mechanism of Figures 3 and 4.

With reference to Figures 1 and 4, a strongroom door has a set of bolts 1 arranged to bethrown from its leading edge 2 (that is, the vertical edge ofthe door remote from the hinge line). The bolts 1 are carried by a bar3which is inturn securedtotheend of a horizontaily-reciprocable drive strap 4. The strap 4 is borne and guided in its movement by a fixed post 5 which extendsthrough a longitudinal slot 6 in the strap, and by the spindle 9 and post 19 mentioned below which extend through a second slot 7. For throwing and withdrawing the bolts 1 there is a rotatable handle 8 accessible atthe frontface ofthe door.This handle turns a spindle 9 upon which a thrower 10 is fastened, the thrower having an eccentric pin 11 passing through a transverse drive slot 12 in the strap 4.To throwthe bolts 1 the handle 8 is rotated to turn the thrower 10 in the sense ofthe arrowAfromthe position shown in Figure 1 to that shown in Figure 2, in so doing the strap 4 being driven to the right (in the sense ofthe Figures) by virtue of the pin-and-slot connection 11112. Return movement of the handle and thrower correspondinglywithdraws the bolts.

Afurthersetofbolts (not shown) are arranged to be thrown from the top edge ofthe door, these being connected to a vertically-reciprocable drive strap 13 borneandguidedbyfixed posts 14,15 extending through longitudinal slots 16, 17. These top-edge boltsarethrown andwithdrawn in unison with the bolts 1 the strap 13 being interconnected with the handle 8 via the strap 4.Thus, a bell-crank lever 18 is pivoted on a fixed post 19 and carries a first eccentric pin 20 engaging in a transverse slot 21 in the strap 4 and a second eccentric pin 22 engaging in a transverse slot 23 in the strap 13, so that as the strap 4translates between the Figures 1 and 2 positions to throw and withdrawthe bolts 1 the strap 13 is driven through the bell-.cranktotranslate in a corresponding manner perpendicularly to the strap 4to throw and withdraw its own bolts.

In order to lockthe above-described boltworkwhen in itsthrown condition two locks 24and 25 are provided. Lock 24 has a bolt 26 connected by a pin 27 to a recipricable locking bar 28. The bar 28 is borne in parallel with the strap 4 by means ofthe spindle 9 and post 19 extending through a longitudinal slot 29 inthe bar. When the lock 24 is unlocked and the bolt 26 and bar 28 a re are accordinglywithdrawn, as shown in Figure 1, no constraint is imposed upon the movement ofthe thrower 10 and straps 4 and 13. As will be appreciated from the Figures, as the thrower 10 is turned to throw the boltwork its extended pin 11 passes directly in front ofthe nose of the locking bar.Operation of the lock 24 subsequentto throwing the main boltwork projects the bar 28 into the Figure 2 position in which a cut-out in the nose ofthe bar defining two abutment surfaces 28A and 28B, is placed into proximity with the thrower pin 11. In this condition the bolts 1 are securely locked againstforced retraction. Firstly, end pressure applied to the bolts 1 is resisted directly through the strap 4 bythethrower pin 11 extending through the slot 12 and in abutmentwith the surface 28A ofthe locking bar 28.Secondly, as will be appreciatedfrom Figure 2,the pin 11 is now in an "overcentre" position in relation to the spindle 9 so thatthetendencyofsuchend pressure is to turn the thrower 10 further in the throwing direction to press the pin 11 hard againstthe lower end ofthe drive slot 12, and not in the withdrawing direction. Thirdly, movementofthepin 11 inthewithdrawing direction is positively blocked by the surface 28B of the locking bar, thus locking the handle 8, spindle 9 and thrower 10 in position and preventing the use of those components to putforce on the strap 4 in the withdrawing direction.

By virtue ofthe connection of the drive strap 13 to the drive strap 4through the crank 18, locking the strap 4 as described above also serves to resistforced retraction ofthe top-edge bolts connected to the strap 13. Additional security is provided by the lock 25 which serves to place further abutments in the return paths of both strap4 and strap 13. To this end the lock bolt 30 is pinned at31 to a locking lever 32 borne on a pivot 33.

When the bolt 30 is thrown the lever 32 is accordingly pivoted from the Figure 1 to the Figure 2 position in which an upturned flange 32A on the lever is placed behind the inner end of strap 4to block retraction of the bolts 1, andthetop surface32B ofthe lever is placed behind a bar 34welded tothe surface ofthe strap 13, to block retraction ofthetop-edge bolts.

Figure 3 shows the addition to the above-described mechanism of two "live" relockers 35 and 36 to provide yetfurther resistance to the forced retraction of straps 4 and 13. The unit35 is shown to a larger scale in Figure 5. It comprises anessentiallytriangular, flat locking member 37 borne on a pin 38 between the bifurcated end of the post 5. Aspring 39 biases the member 37 anti-clockwiseasviewedto urge its nose into the slot 6 in the strap 4, but in the unlocking condition the member37 is held out ofthe slot 6 by the tension in a cord 40 to which it is anchored. Returning to Figure 3, the cord 40 passes from the relocker around a pulley 41 on the end ofthe post 19, a second pulley 42 on the pin 31 ofthe lock bolt 30, and a third pulley 43, to be anchored at its other end to a glass plate 44. As will be appreciated, the effective length of the run of cord 40 between the pulleys 43 and 41 is shortened and lengthened as the pulley 42 moves with the lock bolt 30 as the latter is thrown and withdrawn, so that in normal operation the locking member37 is allowed to move under its spring biasto intrude into the slot 6 as the lock 25 is locked but is withdrawn from the slot by the cord 40 when the lock 25 is released.In the event of a forcible attack aimed at breaching the door, however, the plate 44 is liable to be shattered or the cord 40 severed or dislodged from one or other of its pulleys, in any such case the tension in the cord being relieved such that the locking member 37 remains engagedwith the slot 6 under its spring bias irrespective ofthe position ofthe lock bolt 30. In other words this relockercan remain in place to resist retraction ofthe main boltworkthrough strap 4 even if the lock 25 should be rendered inoperative and its bolt withdrawn.As shown in Figure 5, the nose of the member37isconfiguedin relationtothe position of its pivot such that the tendency of end pressure on the drive strap 4will be to press the locking member further into the slot 6.

The relocker36 has a locking member45con- structed and arranged in the same manner as member 37, but in this case spring biased towards the slot 16 in drive strap 13. It is normally controlled by a cord 46 which passes around a pulley 47 coaxial with the pulley 41 and which is anchored at its other end through the pin 27 which connects the bolt 26 of lock 24to the bar 28 (see also Figure 4).Thusthe member 37 is normally engaged and disengaged through the cord 46 as the lock bolt 26 is thrown and withdrawn, but in the event of an attack leading to the severing or dislodgement ofthe cord 46 (which is particularly likely if an attempt is madeto drill outthe pin 27) this relocker can remain in place to resist retraction ofthe main boltworkthrough strap 13 even if the lock24 should be rendered inoperative and its bolt with drawn.

Preferably, and as shown in Figure 4, a plate 48 is interposed between the pulleys 41,47 and the front face ofthe door. This plate is located over the post 19 and the inner end of the spindle 9 but the plate and pulleys are retained only by relatively light, "push-on" type fittings 49 and 50. Consequently, if an attempt is made to penetrate the door in the region of the plate 48 the plate is liable to be displaced inwards and push off the fittings 49 and 50, atthe same time pushing the pulleys41 and 47from the end ofthe post 19 and ensuring the operation of both relockers 35 and 36.

Claims (12)

1. A locking mechanism for the door of a security enclosure which comprises: boltwork; a mechanical transmissionforthrowing and withdrawing the boltwork in response to corresponding operation of an externally-accessible operating member; and at least one lockfor selectively locking the boltwork in its thrown condition; wherein the transmission includes a rotatable thrower having a projection engaging a drive slot in a linearly-movable transmission member connected with bolts of said boltwork which are thrown from an edge ofthe door, whereby rotation of the thrower in either sense imparts linear motion to said transmission member in a corresponding sense to throw orwithdrawthose bolts; and wherein a said lock isarranged to lock those bolts when in their thrown condition by moving a locking member into a position in which it blocks movement of said projection in the sense of rotation thereof corresponding to withdrawal of those bolts andintnesense of linear motion of said transmission member corresponding to withdrawal ofthose bolts.

2. A mechanism according to claim 1 wherein the boltwork includes further bolts thrown from an edge ofthe door perpendiculrto the first-mentioned edge, and comprising a further linearly-movable transmission member connected with said further bolts and linked to the first-mentioned transmission member through a crank mechanism whereby linear motion of the first-mentioned transmission member in either sense to th row or withdraw the first-mentioned bolts is transmitted into linear motion ofthefurther transmission member in a corresponding sense perpendicularly thereto to throw or withdraw the further bolts.

3. A mechanism according to claim 2 comprising a lockwhich is selectively operable to lockthe boltwork in its thrown condition by moving a locking member into a position in which it blocks the linear motion of both said transmission members in the respective senses corresponding to withdrawal of the first-mentioned and further bolts.

4. A mechanism according to any preceding claim wherein the first-mentioned locking member is arranged for linear movement into its locking position and is borne by means of a slot formed in the locking member engaging around a spindle by which said thrower is rotated.

5. A mechanism according to any one of claims 2 to 4 wherein the first-mentioned locking member is arranged for linear movement into its locking position and is borne by means of a slot formed in the locking member engaging around a pivot means of said crank mechanism.

6. A mechanism according to any preceding claim further comprising a relockercomprising a pivotallymounted locking member spring-biased towards a locking position, and a flexible tension member attached to the locking memberfor holding that memberawayfrom its locking position; the locking member having a tapered nose which in the locking position is arranged to engage with the first-mentioned transmission member; and said nose ofthe locking member being so configured in relation to the pivotal axis thereof that the tendency offorced retraction ofthe first-mentioned transmission mem berwhile the locking member is in its locking position isto urge the locking member further in the sense of rotation in which it moves to its locking postion.

7. A mechanism according to any one of claims 2 6furthercomprising a relockercomprising a pivotallymounted locking member spring-biased towards a locking position, and a flexible tension member attached to the locking memberfor holding that member away from its locking position; the locking member having a tapered nose which in the locking position is a rranged to engage with said fu rther transmission member; and said nose of the locking member being so configured in relation to the pivotal axisthereofthatthetendencyofforced retraction of thefurthertransmission member while the locking member is in its locking position is to urge the locking member further in the sense of rotation in which it moves to its locking position.

8. A mechanism according to claim 6 or claim 7 wherein a said transmission member is guided in its linear motion by means of a slot formed in that member engaging around a post; and the locking member of a respective said relocker is borne by said post with the nose ofthat locking member entering said slot when in the locking position.

9. A mechanism according to any one of claims 6 8wherein a said flexible tension member passes around a pulley which is arranged to move to operate the respective locking member by operation of a said lock.

10. A mechanism according to any one of claims 6 - 9 comprising a plate which is retained loosely in a position in which its projected area covers a significant part ofthe locking locking mechanism, said plate being adapted to displace a pulley around which a said flexible tension member passes ifthe plate is displaced inwards with the respectto the door.

11. A locking mechanism for the door of a security enclosure comprising boltworkfor securing the door closed when thrown; one or more primary locks for selectively locking the boltwork in its thrown condition; and a relockeradaptedto lockthe boltworkin its thrown condition, independently of the state ofthe primary lock(s), in response to the detection of an attack upon the enclosure; the relocker including a pivotally-mounted locking member having a tapered nose which, in the locking position thereof, is arranged to engage with a movable transmission member by which said boltwork isthrown and withdrawn; and said nose of the locking member being so configured in relation to the pivotal axis thereof that the tendency of forced retraction of the transmission memberwhilethe locking member is in its locking position isto urge the locking member further in the sense of rotation in which it moves to its locking position.

12. A locking mechanism forthe door of a security enclosure substantially as herein before described with reference to Figures 1 and 2 or Figures 3-5 ofthe accompanying drawings.