GB2101672A - Security closure - Google Patents

Abstract

A pair of deadlocks 14 and 15 mounted respectively adjacent the top and bottom of a door 10 have their dead bolts 19 connected together by an operating bar 26 so that they can be extended and retracted together by means of a handle 32 of a combined deadlock and latch mechanism 16. A lug 37 on a key-operated dead bolt 35 and a slot 40 in the operating bar 26 form a mechanical interlock which ensures that the dead bolt 35 cannot be extended until the bolts 19 have been extended, and that the dead bolts 19 cannot be retracted unless the bolt 35 is first retracted. Extension of the dead bolts 19 is performed by moving the handle 32 upwardly from a horizontal position, the handle then returning automatically to its horizontal position without retracting the dead bolts 19. Retraction of the dead bolts 19 is achieved by moving the handle downwardly from its horizontal position, which also retracts a latch bolt 41. Such an action of the handle 32 is permitted by lost motion between the handle and the operating bar 26 imparted by a lug 56 which rotates with the handle and an arcuate slot 55 in an operating cam 54 which is coupled to the bar 26. <IMAGE>

Description

SPECIFICATION Security closure This invention relates to a closure, for example a door, and more particularly to a security closure.

According to the present invention, there is provided a security closure comprising a closure member which can be opened and closed with respect to a frame, a pair of latches spaced apart along the periphery of the closure member and including respective bolts which can be extended to retain the closure member in its closed position, and locking means which is actuable only when operating means of a predetermined one of the latches has been operated to extend the respective bolt, the locking means when actuated being arranged to lock both of the bolts in their extended positions.

Desirably, said predetermined one of the latches is a manually operated deadlock, the other of the latches is a key-operated deadlock, and the locking means comprises an interlock which prevents the key-operated deadlock from being actuated unless the manually operated deadlock is first actuated, and which also prevents the manually operated deadlock from being deactuated unless the key-operated deadlock is first de-actuated.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a sectional plan view of part of a security closure according to the present invention; Fig. 2 is a sectional side view of three latches which form an operative part of the security closure shown in Fig. 1; Fig. 3 is a similar view to Fig. 2, but showing the latches in a different position; and Figs. 4 and 5 are sectional views of respective parts of one of the latches shown in Figs. 2 and 3.

Referring first to Fig. 1, the illustrated security closure comprises a door 10 which is hinged to a frame 11 so that it can be opened and closed with respect to the latter, the door in its closed position abutting against a stop 12 on the frame.. The door 10 and the frame 11 can be made of wood, metal (such as aluminium), plastics or any other suitable material.

Referring now also to Figs. 2 and 3, the door 10 is provided-on an edge 13 thereof with a pair of deadlocks 14, 15 and a combined deadlock and latch mechanism 16. The deadlocks 14 and 1 5 are disposed adjacent the upper and lower ends of the edge 13 respectively, and the mechanism 1 6 is disposed generally mid-way along the edge 13. In an alternative arrangement (not shown), the deadlocks 14 and 1 5 are provided respectively on upper and lower edges of the door rather than on the edge 13.

The deadlocks 14 and 15 are of generally identical construction, and each comprises a casing 1 7 and a dead bolt 1 9 which is mounted in the casing for sliding movement relative thereto between a retracted position (as shown in Fig. 2) and an extended position (as shown in Fig. 3) in which a tongue 20 thereof protrudes through an opening 21 in the edge 13 of the door. The dead bolt 19 is retained resiliently in each of these positions by a spring member 22 which engages a detent 23 in the bolt when the latter is retracted and an end of the bolt remote from the tongue 20 when the bolt is extended.

When the door 10 is in its closed position and both bolts 1 9 are extended, the tongues 20 thereof engage in respective recesses 24 in the frame 11 (see Fig. 1, in which only one such recess and bolt is shown, it being understood that the other recess and bolt are identical thereto). A surface 20' of the tongue of each bolt which faces away from the stop 12 is inclined with respect to the plane of the door, and is arranged to abut against a striker plate 25 in the respective recess 24.This arrangement ensures that both the top and bottom of the door are urged into engagement with the stop 1 2 despite any distortion which may be present in the door, due for example to warpage or defective or aged materials, and also ensures that the door is held securely in its closed position even when subjected to external forces, such as wind pressure.

An elongate operating bar 26 extends between the deadlocks 14 and 1 5 within the body of the door, and is constrained to move in the vertical direction. The bar 26 is operatively engaged with the bolt 19 of each deadlock 14, 15 by means of an operating cam 27 which is pivotally mounted on the casing 1 7. A pin 28 fixed to the bar 26 is slidably located in a vertical slot 17' in the casing 17. the pin 28 is received in a recess 29 in one arm of the cam 27, while a pin 30 on another arm of the cam is slidably received in a vertical slot 31 in the bolt 19.The bolts 19 can be extended and retracted in unison by downward and upward movement of the bar 26, respectively, such movement of the bar being effected in a manner to be described later by means of a manually graspable, pivotable handle 32 (only a part of which is shown) which forms part of the combined deadlock and latch mechanism 1 6.

The mechanism 1 6 comprises a casing 34 within which is mounted a conventional keyoperated deadlock having-a dead bolt 35 which can be extended from and retracted into the casing 34 by appropriate operation of a key inserted into a key hole 36. A lug 37 fixed to the dead bolt 35 protrudes through a slot 38 in the casing 34. When- the bolts 1 9 of the upper and lower deadlocks 14, 15 are in their retracted position, -movement of the dead bolt 35 into its fully extended position is prevented by engagement of the lug 37 with an edge 39 of the operating bar 26. However, when the bolts 19-are in their extended positions, a slot 40 in the bar 26 becomes aligned with the slot 38 in the casing 34, thereby permitting the lug 37 to move along the full length of the slot 38 and the dead bolt 35 to be fully extended.When the dead bolt 35 is in its fully extended position, the engagement of the lug 37 in the slot 40 prevents the operating bar 26 from being moved vertically to retract the bolts 19. Thus, the lug 37 and the slot 40 provide a mechanical interlock which prevents the keyoperated deadlock from being actuated unless the upper and lower deadlocks 14, 15 are first actuated, and which prevents the upper and lower deadlocks from being de-actuated unless the keyoperated deadlock is first de-actuated.

Referring now also to Figs. 4 and 5, a latch mechanism is also mounted within the casing 34, and comprises a latch bolt 41 which is movable between extended and retracted positions upon operation of the handle 32. The bolt 41 is biased by a spring 42 into an extended position, movement of the bolt under the action of this bias being limited by a stop 43 on the latch bolt which slides along a slot 44 in the casing 34. An operating member 45 is pivotally mounted on the casing 34 and has an arm 46 which engages an abutment 47 on the latch bolt 41 such that rotation of the operating member 45 in a clockwise direction (as viewed in Fig. 4) causes the bolt 41 to retract against the bias of the spring 42. A torsion spring 48 engages the arm 46 and acts to bias the operating member 45 in a clockwise direction.A similar torsion spring 44 engages a further arm 50 of the operating member 45 and acts to bias the latter in an anticlockwise direction. The biasing effects of the springs 48 and 40 cause the operating member 45 to be urged naturally into a neutral position, as shown in Fig. 4.

The operating member 45 has a squaresection aperture 51 therein through which a correspondingly shaped spindle 52 extends, the spindle 52 being keyed for rotation with the handle 32 by means of a bush 53. In the illustrated embodiment, the handle 32 is of lever type and occupies a generally horizontal position (as indicated by solid lines in Figs. 2 and 3) when the operating member 45 is in its neutral position.

Movement of the handle downwardly into the position indicated by chain-dotted lines in Fig. 2 causes the operating member 45 to pivot in a clockwise direction (as viewed in Fig. 4) against the bias of the spring 49, thereby retracting the latch bolt 41 as described above. When released, the handle 32 is returned to its generally horizontal position by the action of the spring 49 on the operating member 45, and the latch bolt 41 is returned to its extended position by the spring 42.

An operating cam 54 is freely mounted on the bush 53 for rotation relative thereto, and has an arcuate slot 55 in its periphery along which a lug 56 on the bush 53 is movable. The operating cam 54 also has a recess 57 in which is received a pin 58 fixed to the operating bar 26. The angular position of the operating cam 54 is thus determined by the vertical position of the bar 26, which in turn depends on whether the bolts 1 9 of the deadlocks 14 and 1 5 are extended or retracted. When the bolts 1 9 are retracted, the operating cam 54 occupies the position shown in Figs. 2 and 5, and the lug 56 is disposed at one end of the slot 55 when the handle 32 occupies its generally horizontal position.The lug 56 is thus free to move along the slot 55 (as indicated in broken line at 56' in Fig. 2) when the handle 32 is moved downwardly in the above-described manner to retract the latch bolt 41.

In order to extend the bolts 19, the handle 32 is moved upwardly to the position indicated in chain-dotted lines in Fig. 3. By this action, the lug 56 is urged against the adjacent end of the slot 55 and rotates the operating cam 54 in an anticlockwise direction as viewed in Fig. 5, thereby moving the operating bar 26 downwardly and extending the bolts 1 9. The operating cam 54 then occupies the position shown in Fig. 3, it being appreciated that the operating cam is viewed in this figure from the opposite side as compared with Fig. 5, and the lug 56 is disposed as indicated in broken line at 56" in Fig. 3.As the handle 32 is moved upwardly in this manner, the operating member 45 is rotated anticlockwise against the action of the spring 48: the amount by which the operating member 45 can be rotated, and thus the amount by which the handle 32 can be raised, is limited by a fixed stop 59 disposed in the path af movement of the arm 50. During such rotation of the operating member 45, the latch bolt 41 remains in its extended position.

When released from its raised position, the handle 32 is returned to its generally horizontal position by the action of the spring 49 on the operating member 45. At the same time, the lug 56 on the bush 53 moves along the slot 55 in the operating cam 54 to the opposite end thereof; the operating cam 54 thus remains in its rotated position, and the bolts 1 9 remain extended. The mechanism is now in the condition shown in Fig.

3, and the key-operated deadlock can now be actuated to extend the dead bolt 35, as described previously.

In order to retract the bolts 1 9 again, the handle 32 is moved downwardly. This causes the lug 56 to bear against said opposite end of the slot 55 and to rotate the operating cam 54 in an anticlockwise direction as viewed in Fig. 3, thereby moving the operating bar 26 upwardly and retracting the bolts 1 9. As described previously, such downward movement of the handle 32 causes the latch bolt 41 to retract: thus, all three of the bolts 1 9 and 41 are' retracted by a single action, enabling the door to be opened. Upon release, the handle 32 is automatically returned to its generally horizontal position by means of the spring 49, whereas the operating cam 54 remains unmoved. The mechanism is thus returned to the same condition as it was in prior to the bolts 1 9 being extended.

In a modification of the above-described construction, the handle 32 is arranged to undergo a small amount of dummy movement before the bolts 1 9 are retracted. In order to achieve this, the slot 55 in the operating cam 54 is extended slightly so that, when the bolts 1 9 are extended and the operating cam is therefore in the position indicated in Fig. 3, the lug 56 is not disposed at the absolute end of the slot 55 when the handle 32 is horizontal. Thus, a certain amount of downward movement of the handle is necessary to bring the lug 56 into engagement with the end of the slot 55 before the operating cam 54 is actually rotated to retract the bolts 1 9.

Since the same amount of angular movement of the operating cam as before will be required to retract the bolts 19, the handle 32 will have a longer downward stroke than upward stroke from its horizontal position.

In a further modification of the abovedescribed construction, each of the cams 27 is replaced by a gear wheel which meshes on the one hand with rack teeth on the operating bar 26 and on the other hand with rack teeth on the respective dead bolt 19. Additionally or alternatively, the operating cam 54 can similarly be replaced by a gear wheel which meshes with rack teeth on the operating bar 26. Thus, the cam action in the above-described construction is replaced by a geared motion. It is to be appreciated that other forms of operative connection between the handle 32 and the operating bar 26, and between the bar 26 and the bolts 1 9 can also be used.

Although not shown, the dead bolt 35 and the latch bolt 41 in their extended positions engage in respective recesses in the frame 11 when the door 10 is closed. In addition, although in the above description reference has been made to one handle 32, it is to be understood that two such handles will normally be provided, one on each side of the door. Furthermore, a facing strip (not shown), for example made of metal, can be secured to the edge 1 3 of the door if desired.

From the above description, it will be apparent that the security closure has the following important features:- (1) The abutment between the inclined surface 20' on the tongue 20 of each dead bolt 19 and the respective striker plate 25 ensures that the door is pressed tightly against the frame stop 12 when the bolts 19 are extended.This counteracts the effects of any distortion of the-door and ensures that the door is held securely in its closed position despite any such distortion which may be present and any external pressures which may be applied to the door In order to enhance this effect, additional deadlocks similar to the units 14 and 1 5 can be provided at spaced-apart positions around the edge of the door: the scope of the present invention is thus not intended to be restricted to the provision of only two such deadlocks.

(2) The mechanical interlock provided by the lug 37 on the dead bolt 35 and the slot 40 in the operating bar 26 ensures that the dead bolts 1 9 must be extended before the key-operated deadlock can be actuated. Thus, the door cannot be locked unless the deadlocks 14, 1 5 have been manually actuated by means of the handle 32.

Moreover, when the key-operated deadlock has been actuated, the bolts 1 9 cannot be retracted without the key-operated deadlock first being deactuated. The mechanical interlock therefore provides for additional security.

(3) Whilst conventional operation of the latch bolt 41 is retained, the same handle as is used to achieve this operation is also utilized to actuate the deadlocks 14 and 1 5. Moreover, movement of the handle to actuate the deadlocks 14 and 15 is in the opposite direction (i.e. upwardly) to that for operating the latch bolt 41, so that the two functions of the handle cannot be confused.

Claims (11)

Claims

1. A security closure comprising a closure member which can be opened and closed with respect to a frame, a pair of latches spaced apart along the periphery of the closure member and including respective bolts which can be extended to retain the closure member in its closed position, and locking means which is actuable only when the operating means of a predetermined one of the latches has been operated to extend the respective bolt, the locking means when actuated being arranged to lock both of the bolts in their extended positions.

2. A security closure as claimed in Claim 1, wherein said predetermined one of the latches is a manually operated deadlock, the other of the latches is a key-operated deadlock, and the locking means comprises an interlock which prevents the key-operated deadlock from being actuated unless the manually operated deadlock is first actuated, and which also prevents the manually operated deadlock from being deactuated unless the key-operated deadlock is first de-actuated.

3. A security closure as claimed in Claim 2, wherein the manually operated deadlock is actuated and de-actuated by means of a manually operable handle, the handle also being operable to extend and retract a latch bolt which is biassed towards an extended position.

4. A security closure as claimed in Claim 3, wherein the- handle is movable between first and second positions and is biassed into a neutral position intermediate the first and second positions, movement of the handle between its neutral and first positions being arranged-to cause extension and retraction of the latch bolt, and movement of the handle from its neutral position to its second position being arranged to cause extension of the bolt of the manually operated deadlock, the latter bolt being retracted upon subsequent movement of the handle from its neutral position to its first position.

5. Asecurity closure-as claimed in any preceding claim, wherein a pair of manually operated deadlocks are provided in spaced apart relation, and are operatively interconnected by an operating member for actuation and de-actuation in unison.

6. A security closure as claimed in Claim 5, wherein the interlock is formed by a projection on the bolt of the key-operated deadlock which is engageable with a slot in said operating member, the operating member being movable generally perpendicularly to the bolt of the key-operated deadlock and the slot being aligned with the projection when the bolt of the manually operated deadlock is extended.

7. A security closure as claimed in Claim 5 or 6, wherein the operating member is an elongate bar which is longitudinally reciprocable, and rotatable cam members operatively connect dead bolts of the deadlocks to the elongate bar, each cam member being coupled to the elongate bar and to a respective one of the dead bolts by means of respective sliding pin and recess connections.

8. A security closure as claimed in Claim 5 or 6, wherein the operating member is an elongate bar which is longitudinally reciprocable, and rotatable gear wheels operatively connect dead bolts of the deadlocks to the elongate bar, each gear wheel meshing with respective rack teeth on the elongate bar and on a respective one of the dead bolts.

9. A security closure as claimed in any one of Claims 5 to 8, wherein the operating member is an elongate bar which is longitudinally reciprocable, and the handle is operatively connected to the elongate bar by a rotatable cam member, the cam member being coupled to the elongate bar by means of a sliding pin-and recess connection.

10. A security closure as claimed in any one of Claims 5 to 8, wherein the operating member is an elongate bar which is longitudinally reciprocable, and the handle is operatively connected to the elongate bar by a rotatable gear wheel which meshes with rack teeth on the elongate bar.

11. A security closure as claimed in Claim 1, and substantially as hereinbefore described with reference to the accompanying drawings.