Door-locking mechanisms for security enclosures

Abstract

 The locking mechanism for the door of a safe or the like has a mechanism A for disengaging the coupling of an external throwing handle to the main boltwork when thrown in addition to locks (3,4) for locking the boltwork. The handle is provided on the end of a shaft (5) which can be coupled to a thrower (6) inside the safe door by means of a sliding link (12) held in the thrower. The link (12) is biased by a spring (15) to engage in a recess (16) in the shaft (5) to establish the drive connection between the shaft (5) and thrower (6). However, when either lock bolt (17,18) is thrown it passes into an aperture (19,20) in the thrower (6) to lock the latter, and furthermore bears upon an inclined face (21,22) of the link (12) to withdraw the link axially from the shaft recess (16).

Description

[0001] The present invention relates to locking mechanisms for the doors of safes, vaults, strongrooms and the like security enclosures.

[0002] It is customary for the door of a safe or the like enclosure to be locked by means of bolts thrown from the door into engagement with the surrounding frame, for which purpose there is provided an externally-accessible handle or the like control member which drives the boltwork through a mechanical transmission mounted within the door, the same mechanism, of course, being used to withdraw the bolts when the door is to be opened. This boltwork is in turn locked in its thrown condition by the operation of one or more locks which may, for example, throw bolts into engagement with portions of the main boltwork to resist the subsequent withdrawal of the main bolts. In order to improve the security of this type of locking arrangement it is also known to provide a mechanism actuated by one of the locks which serves to disengage the boltwork from the external handle when the . bolts are thrown and locked, so that in the event of burglarious attack on the enclosure it is impossible to use the handle to put force on the boltwork or to withdraw the bolts even if the blocking action of the locks can be overcome.

[0003] In one aspect the invention seeks to provide an improved boltwork isolating arrangement in a door locking mechanism generally as described above, and which in particular can achieve reliably this disengaging function with a minimum of moving parts and a minimum space requirement.

[0004] Accordingly the invention resides in a locking mechanism for the door of a security enclosure which includes: boltwork; a control member accessible from outside the door; a mechanical transmission for coupling said control member to the boltwork for throwing and withdrawing the same; one or more locks for selectively locking the boltwork in its thrown condition; and means for selectively disengaging the coupling of said control member to the boltwork when in its thrown condition; wherein the mechanical transmission includes a pair of coaxial rotary members a first of which is caused to rotate in either sense by corresponding movement of said control member and the second of which is adapted to engage the first in order to transmit movement of the control member to the boltwork; and the disengaging means .are operable to relatively displace said pair of rotary members in the axial sense thereby to disengage the coupling between them. The engagement of the two rotary members may be established by means of a non-circular portion of one of the members entering a complementary freedom for axial motion in a complementary slot in the next succeeding member of the transmission such that rotation of the second rotary member is transmitted into rotation of said succceeding member. This succeeding member may constitute the part of the transmission with which the lock bolt(s) engage to lock the boltwork in an arrangement as indicated in the preceding paragraph.

[0005] The invention is furthermore concerned with improving the security of the boltwork itself in a safe door or the like. In this respect it is highly desirable that bolts which are thrown from the door edges into engagement with the surrounding frame are well supported over an appreciable axial length within the door, in order to resist attempts at twisting the bolts in their mountings, by use of explosives or jacks for example; this is particularly so in the case of bolts thrown from the door edges which are parallel to the hinge line - ie from the vertical (side) door edges. If such support for the bolts is to be achieved it follows that the bolts will occupy at least a substantial proportion of the width of the door, if not the entire width, when withdrawn. With known doors embodying a boltwork locking and isolating mechanism it has proved difficult to provide such bolt support and at the same time accommodate the locking and isolating components in the available space within the door. In a mechanism according to the invention, however, a dispostion of parts can readily be achieved such that it is practical to locate both the aforesaid lock(s) and disengaging means in a space which lies entirely between the lines of action of successive vertically-spaced bolts, thus leaving the entire width of the door free for accommodating the bolts if desired.

[0006] non-circular recess in the other, so as to provide both • for the transmission of rotary motion between the two members and for the required relative axial motion on disengagement.

[0007] Preferably one of the pair of rotary members has a face inclined to the axis of those members and the member with the inclined face is displaced axially relative to the other member when the disengaging means are operated, by virtue of the camming action of an operating member thrust against said inclined face, preferably in a radial direction relative to said axis.

[0008] Preferably the disengaging means are operatively associated with a said lock for selectively locking the boltwork in its thrown condition, whereby operation of the lock acts also to disengage the coupling between the pair of rotary members as aforesaid. In such a case the aforesaid operating member may comprise the bolt of a lock which serves to lock the boltwork by its engagement with part of the said transmission. There may be two locks either of which is effective to disengage the coupling between the pair of rotary members, in which case the locks are preferably arranged on opposite sides of the said axis and each has a bolt engageable with a respective said inclined face. Alternatively, however, the disengaging means could be embodied eg as an independent key or combination operated mechanism, separate from any such lock, if desired.

[0009] In a preferred arrangement it is the aforesaid second rotary member which is displaced to effect'the required disengagement, and this member may be borne with limited

[0010] These and other features of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings illustrating portions of a preferred embodiment of a safe door incorporating a locking mechanism according to the invention, in which

Figure 1 is a section, taken on the line I-I of Figure 2, through the locks and handle/boltwork-isolating mechanism of the safe;

Figure 2 is a section taken on the line II-II of Figure 1;

Figure 3 is an elevation, partly in section, of the boltwork incorporated in the safe, shown in its withdrawn condition;

Figure 4 is a view similar to Figure 3 but showing the boltwork in its thrown condition; and

Figure 5 is a section on the line V-V of Figure 4.

[0011] Referring to Figures 1 and 2, the illustrated locking and isolating unit A includes a mounting block 1 which is secured within a steel pan 2 on the inside face of the safe door. Two locks 3 and 4 are mounted to the block 1, in the illustrated example lock 3 being a combination lock and lock 4 being a keylock, although other permutations of lock type are possible. The boltwork of the door is operated by turning an external handle (not shown) mounted on the end of a shaft 5, it being necessary to establish a driving connection between the shaft 5 and a coaxial thrower 6 borne by the block 1 if the turning of the handle is to be effective to throw or withdraw the boltwork. Movement of the thrower 6 is transmitted to the boltwork through four drive rods 7-10 pinned to the thrower (of which three are seen in Figure 1), as will be more fully described hereafter.

[0012] As will be seen from Figures 1 and 2, the thrower 6 has a longitudinal slot 11 within which is borne a drive element 12 of rectangular cross-section. This drive element is capable of axial movement relative to the thrower within limits set by a cross-pin 13 held by the thrower and extending through a slot 14 in the element 12. The drive element is biased towards one of its limiting positions by means of a compression spring 15 captive in the thrower, and when the element 12 is free to move under the bias of the spring it can project from the thrower to engage in a rectangular recess 16 in the adjacent end of the shaft 5; (in Figure 1 the shaft 5 is shown rotated through 90° from the position in which it can engage with the element 12). When these components are engaged rotation of the shaft is transmitted into rotation of the thrower for throwing or withdrawing the boltwork as appropriate.

[0013] Normally, however, when the safe door is closed and locked, the drive element 12 is maintained in the position in which it is shown in Figure 1, ie out of engagement with the shaft 5 which latter can accordingly turn without putting any force on the boltwork. This disengagement is achieved by operation of the locks 3 and 4.

[0014] To this end, each lock has a bolt 17,18 with a'tapaered nose which, when the bolt is thrown, extends through the block 2 and into a respective radial aperture 19,20 in the thrower 6, where the nose engages a respective inclined surface 21,22 on the drive element '12 to withdraw that element from the shaft 5 by a camming action, against the bias of the spring 15. As will be appreciated, throwing either of the lock bolts 17 or 18 will achieve this disengagement, although in point of fact the inclined surface 21 of the element 12 which cooperates with the combination lock bolt 17 is undercut slightly as compared with the other inclined surface 22, so that when both lock bolts have been thrown the force of the spring 15 is met by the keylock bolt 18 only and the combination lock bolt 17 is not loaded. By their entry into the apertures 19 and 20 the bolts 17 and 18 also, of course, interlock the thrower 6 to resist any subsequent attempt at forced retraction of the boltwork. Furthermore, the lock bolts have lateral extensions 23,24 which in this position block withdrawing movement of rods 25 and 26 carried with the top and bottom boltstraps of the main boltwork, as will be more fully described hereafter. Arranging the locks as shown in the Figures, with their bolts facing each other across the thrower, assists not only in the provision of a very compact unit but also in resisting attempts to overcome the locking mechanism by knocking in the lock bolts.

[0015] In the illustrated embodiment there is also a mechanism, operated by the combination lock 3, for blocking access to the keyhole 27 of the keylock 4 in all conditions except when the combination lock is released. This mechanism comprises a plate 28 which can be slid relative to the keylock between two positions, in one of which an aperture 29 in the plate (Figure 2) registers with the keyhole 27 to provide access for the key and in the other of which (as illustrated) the aperture 29 is withdrawn from registry with the keyhole. The plate 28 is·connected via a toggle lever 30 and slide 31 to a bar 32 which moves together wth the bolt assembly of the combination lock 3 to effect the required movement of the plate. It is also preferred to block the whole of the key-entrance 33 (Figure 1) which extends through the safe door, whenever the door is closed and locked. To this end, after the keylock 4 has been thrown and the key removed, but before the combination lock is thrown, a profiled steel section (not shown) is inserted into the entrance 33 and through the plate aperture 29 into the keyhole, and the combination lock 5 is then thrown to slide the plate 28 so that a narrow extension 34 of theplate aperture 29 moves over a waisted portion at the end of the steel section to retain it in place.

[0016] It will also be seen from Figure 2 that the thrower 6 has a third radial aperture 35. The purpose of this is to enable the keylock 4 to be re-thrown after the main boltwork has been withdrawn and the door has been opened, in withrdawing the main boltwork the thrower 6 having been rotated into the position in which the aperture 35 aligns with the lock bolt 18. This is of value both in enabling the key to be removed from the lock 4 (if the lock is of a key-retaining kind) and in re-locking the thrower to prevent tampering with the throwing mechanism. The presence of the rod 25, which in this condition will have been withrdawn with the main boltwork to extend through the whole of its guideway in theblock 1, does not block this re-throwing of the keylock as the rod 25 is provided with an appropriately positioned notch (not. shown) which permits the bolt extension 24 to pass. Throwing of the combination lock 3 is, however, precluded in this condition as there is no corresponding additional aperture for the bolt 17 in the thrower 6.

[0017] Turning now to Figures 3 and 4, these show the general arrangement of the boltwork within the door: This is a four-way boltwork comprising a pair of bolts 36 and 37 interconnected by a strap 38, thrown from the hinge side of the door; a pair of bolts 39 and 40 interconnected by a strap 41, thrown from the top of the door; a pair of bolts 42 and 43 interconnected by a strap 44, thrown from the opening side of the door; and a pair of bolts 45 and 46 interconnected by a strap 47, thrown from the bottom of the door. The side bolt straps 38 and 44 are linked to the thrower 6 by respective pinned drive rods 7 and 9, and thetop and bottom boltstraps 41 and 47 are secured to bars 48 and 49 which in turn are linked to the thrower 6 by respective pinned drive rods 8 and 10. Each one of the bolts is journalled at two positions along its length, one position provided by the side wall of the pan 2 and the other by a respective bearing block 50 welded to the face of the pan.

[0018] The hinge-side and opening-side bolts are arranged in opposed pairs 36, 42 and 37, 43 and it will be seen from Figure 3 that in the withdrawn condition these bolt pairs extend across virtually the entire width of the door. It will be appreciated from Figures 3 and 4, together with Figure 5, that this is made possible by mounting the locking and isolating unit A completely within the space between the lines of action of the successive vertically-spaced bolt pairs 36/42 and 37/43. Movement of the bolts from the Figure 3 to Figure 4 position is achieved by appropriate rotation (in the clockwise sense as viewed) of the thrower 6, and it will be further appreciated from Figure 4 that the arrangement maximises the-length over which the side bolts 36,37,42 and 43 are supported within the door and at the same time permits the bolts to be thrown through a relatively long distance. Typically with the illustrated arrangement the hinge-side, top and bottom bolts are thrown a distance of 50mm while the opening-side bolts 42 and 43 opposite the hinge line are thrown through 80mm, the increased throw for the latter being achieved by linking the drive rod 9 to the thrower 6 at a greater radius from the axis of rotation X of the thrower than the other drive rods 7,8 and 10.

[0019] As previously indicated, when the boltwork is thrown and the locks 3 and 4 operated, the external handle is disengaged from the thrower and forced retraction of the boltwork is resisted by the lock bolts engaging the thrower 6. Retraction of the top and bottom bolts 39,40 45 and 46 will also be resisted by the lock bolts blocking the paths of movement of rods 25 and 26 carried with the boltstraps 41 and 47 and extending into the central section of the mounting block 1. In addition, forced retraction of the side bolts will be resisted by the positioning of respective abutment bars 51 and 52, which are carried by the bars 48,49 together with the top and bottom boltstraps 41,47, between the inner ends of the bolts in each opposed pair 36/42 and 37/43. For example, if an attempt were made to knock the bolt 42 inwards when thrown it would engage the bar 51 and eventually through it the bolt 36 which latter is received in a detention in the opposite side of the door frame. The bolt 36 therefore is prevented from being knocked further outwards from the door and thus prevents the bolt 42 from being knocked inwards sufficiently far to disengage from its own detention; in effect, the bolts react against each other to resist retraction of either one.

[0020] In order to permit the bars 51 and 52 to be placed closely between the side bolts without fouling the bolts in their movement the relative angular positions at which the drive rods 7-10 are linked to the thrower 6 are so selected that during the initial stage of throwing movement the boltstraps 38 and 44 move at a higher linear rate than the boltstraps 41 and 47 to make way for the bars 51 and 52, and conversely during the initial stage of withdrawing movement the boltstraps 41 and 47 move at a higher linear rate than do the straps 38 and 44.

[0021] Although described and illustrated in terms of its application to boltwork having only two bolts thrown from each vertical door edge, this locking mechanism can readily be adapted for doors of sizes and proportions which require a greater number of vertical-edge bolts. In such a case the boltstraps 38 and 44 are extended in length (upwards and/or downwards relative to the position of the locking/isolating unit A) to carry the required number of bolts, and the bars 48,49 are correspondingly extended between their points of connection to the drive rods 8,10 and boltstraps 41,47, to carry the requisite number of abutment bars 51,52 for each opposed pair of side bolts.

Claims

1. A locking mechanism for the door of a security enclosure which includes: boltwork (36,37,39,40,42,43,45,46); a control member accessible from outside the door; a mechanical transmission (5,12,6,7-10) for coupling said control member to the-boltwork for throwing and withdrawing the same; one or more locks (3,4) for selectively locking the boltwork in its thrown condition; and means (17,18) for selectively disengaging the coupling of said control member to the boltwork when in its thrown condition; characterised in that the mechanical transmission includes a pair of coaxial rotary members (5,12) a first (5) of which is caused to rotate in either sense by corresponding movement of said control member and the second (12) of which is adapted to engage the first in order to transmit movement of the control member to the boltwork; and the disengaging means (17,18) are operable to relatively displace said pair of rotary members (5,12) in the axial sense thereby to disengage the coupling between them.

2. A locking mechanism according to claim 1 characterised in that the engagement of the said pair of rotary members (5,12) is established by means of a non-circular portion of one (12) of the members entering a complementary non-circular recess (16) in the other (5).

3. A locking mechanism according to claim 1 or claim 2 characterised in that one (12) of said pair of rotary members has a face (21,22) inclined to the axis (x) of those members and the member (12) with the inclined face is displaced axially relative to the other member (5) when the disengaging means are operated, by virtue of the camming action of an operating member thrust against said inclined face (21,22).

4. A locking mechanism according to claim 3 characterised in that said operating member (17,18) is thrust in a radial direction relative to said axis (x).

5. A locking mechanism according to any preceding claim characterised in that said disengaging means (17,18) are operatively associated with a said lock (3,4), whereby operation of the lock to lock the boltwork acts also to disengage the coupling between said pair of rotary members (5,12) as aforesaid.

6. A locking mechanism according to claim 5 when appended to claim 3 or claim 4, characterised in that said operating member comprises the bolt (17,18) of a said lock (3,4) which serves to lock the boltwork by its engagement with part (6) of the said transmission.

7. A locking mechanism according to claim 5 or claim 6 characterised in that there are two said locks (3,4) either of which is effective to disengage the coupling between the pair of rotary members (5,12).

8. A locking mechanism according to claim 7 when appended to claim 6 characterised in that the said locks (3,4) are arranged on opposite sides of the said axis (x) and each has a bolt (17,18) engageable with a respective said inclined face (21,22).

9. A locking mechanism according to any preceding claim characterised in that it is the aforesaid second rotary member (12) which is axially displaced to disengage the coupling between the pair of such members (5,12).

10. A locking mechanism according to claim 9 characterised in that the aforesaid second rotary member'(12) is borne with limited freedom for axial motion in a complementary slot (11) in the next succeeding member (6) of the transmission such that rotation of the second rotary member (12) is transmitted into rotation of said succeeding member (6).

11. A locking mechanism according to claim 10 and claim 6 or any other claim when appended thereto characterised in that the said succeeding member (6) of the transmission constitutes that part with which the or each lock bolt (17,18) engages to lock the boltwork.

12. A locking mechanism according to claim 11 characterised in that the or each lock bolt is engageable in a respective aperture (19,20) in said succeeding member (6) of the transmission to lock the boltwork, and is engageable through the respective aperture (19,20) with an inclined face (21,22) on the said second rotary member (12) thereby to axially displace said member.

13. A locking mechanism according to claim 7 or any other claim when appended thereto characterised in that one of said locks is a combination lock (3) and the other of said locks is a keylock (4), and wherein operation of the combination lock (3) to lock the boltwork also operates a mechanism (32,31,30,28) to block access to the keyhole (2) of the keylock (4).

14. A locking mechanism according to any preceding claim characterised in that said boltwork comprises spaced bolts (36,37,42,43) arranged to be thrown from both vertical edges of the door, and wherein the or each said lock (3,4) and said disengaging means (17,18) are located in a space which lies entirely between the lines of action of successive vertically-spaced bolts (36/42, 37/43).

15. A locking mechanism according to claim 14 characterised in that said bolts (36/42, 37/43) are of such length that when withdrawn they occupy substantially the entire width of the door.

16. A locking mechanism according to any preceding claim characterised in that said boltwork comprises bolts (39,40,45,46) arranged to be thrown from both the top and bottom edges of the door, the top and bottom bolt structures (41,48,47,49) carry respective rods (25,26) which translate as the respective bolts are thrown and withdrawn, and one or more said locks (3,4) have bolts (17,18) which block forced retraction of said rods when thrown.

Drawing