GB2407841A

GB2407841A - Locking arrangement with multiple locks and anti-jamming construction

Info

Publication number: GB2407841A
Application number: GB0325403A
Authority: GB
Inventors: Anthony John Collingwood
Original assignee: Assa Abloy Ltd
Current assignee: Assa Abloy Ltd
Priority date: 2003-10-30
Filing date: 2003-10-30
Publication date: 2005-05-11
Anticipated expiration: 2023-10-30
Also published as: GB0325403D0; GB2407841B

Abstract

A lock including a double cylinder lock (2) operated by a key from either side of the lock to move a bolt (2c) of the double cylinder lock from a locked to unlocked condition; a further cylinder lock (3) operated by a key from a first side of the lock to move a bolt (102c) of the further cylinder lock from a locked to unlocked condition, and operated by a thumb turn from the second, opposite, side (e.g. interior of premises) of the lock to move the bolt (102c) of the further cylinder lock from the locked to unlocked condition; and a latch arrangement operated manually from both sides of the lock to move a bolt (30) of the latch arrangement from the locked to unlocked condition, the bolts of the double cylinder lock, the further cylinder lock and the latch arrangement being arranged in a keeper (1) such that, when the bolt (30) of the latch arrangement is in the keeper, the bolts (2c and 102c) of the double cylinder lock and the further cylinder lock are prevented from pressing against the keeper in a direction towards said second side of the lock, thus preventing the bolts 2c, 102c from jamming in the keeper.1.

Description

240784 1 - 1 Locks This invention relates to locks, and more particularly

to cylinder locks.

The invention addresses the potential conflict between on the one hand the need for a lock to be able to secure a building and on the other hand the need for any occupants of the building to be able to escape, especially in the event of fire.

Cylinder locks for doors are known in which a thumb turn is provided on the inside of the door to provide easy escape in the event of fire. Such thumb turns provide an easy route of access for an intruder. To enhance security, double cylinder locks are sometimes used. Such double cylinder locks have co-axial cylinders operated by keys inserted from opposite sides of the door. Security is increased because a key is needed even to open the door from the inside. The lock is, however, less safe in the event of fire because an occupant of a building locked in such a way requires a key to open the lock.

A further problem that can arise is that a significant force may be required to turn the thumb turn. That can be a particular issue if the thumb turn is to be operated in an emergency, for example to escape from a fire. The need to exert a significant force can arise from compression of a door seal when the door is closed, giving rise to substantial force between the bolt of the lock and its keeper. - 2

It is an object of the invention to provide a lock that overcomes or mitigates the disadvantages referred to above.

According to the invention there is provided a lock including: a double cylinder lock able to be operated by a key from either side of the lock to move a bolt of the double cylinder lock from a locked condition to an unlocked condition; a further cylinder lock able to be operated by a key from a first side of the lock to move a bolt of the further cylinder lock from a locked condition to an unlocked condition, and able to be operated by a thumb turn from the second, opposite, side of the lock to move the bolt of the further cylinder lock from the locked condition to the unlocked condition; and a latch arrangement able to be operated manually from both sides of the lock to move a bolt of the latch arrangement from the locked condition to the unlocked condition, the bolts of the double cylinder lock, the further cylinder lock and the latch arrangement being arranged in a keeper such that, when the bolt of the latch arrangement is J n the keeper, the bolt of the double cylinder lock and the further cylinder lock are prevented from pressing against the keeper in a direction towards said second side of the lock. - 3

By adopting a lock that includes the combination of the double cylinder lock, further cylinder lock and latch arrangement all as defined above, it becomes possible to provide a lock that can be secure and yet need not cause extra obstruction to escape in the event of a fire: the double cylinder lock can be locked only when the space it is securing is unoccupied and in that situation can provide extra security; when the double cylinder lock is not locked, the thumb turn of the further cylinder lock, which would be fitted on the inside (the second side of the lock defined above), enables an occupant to escape easily from the locked spaces furthermore, the arrangement of the bolt of the latch arrangement in the keeper facilitates the turning of the thumb turn to unlock the further cylinder IS lock. Thereafter, the bolt of the latch arrangement can be retracted by operating a handle which may be a lever handle and make retraction of the bolt easy.

Various arrangements are possible for ensuring that, when the bolt of the latch arrangement is in the keeper, the bolt of the double cylinder lock and the further cylinder lock are prevented from pressing against the keeper in a direction towards said second side of the lock.

For example, inner faces of portions of the bolts of the double cylinder lock and the further cylinder lock may be offset towards said first side of the lock from an inner face of the bolt of the latch arrangement. Alternatively, or additionally, the keeper of the lock may be provided with respective locking faces for engaging the bolts of the double cylinder lock, the further cylinder lock and the latch arrangement to prevent movement of the bolts when they are in the locked condition towards the second side of the lock, the locking faces for engaging the bolt of the double cylinder lock and for engaging the bolt of the further cylinder lock being offset towards the second side of the lock from the locking face for engaging the bolt of the latch arrangement.

In an especially preferred embodiment of the invention, the double cylinder lock is also able to be operated by a key from the first side of the lock to move the bolt of the double cylinder lock from the unlocked condition to the locked condition, but a blocking arrangement is provided for blocking movement of the bolt of the double cylinder lock from the unlocked condition to the locked condition through operation of a key from said second side of the lock. The inclusion of such a blocking arrangement can avoid an occupant locking the double cylinder lock from the inside, which could impede escape.

In one implementation of the blocking arrangement, a key inserted into the double cylinder lock from said second side of the lock is able to be turned from its initially inserted position in one direction only. Preferably, the double cylinder lock includes an inner plug on the second side of the lock, the inner plug having a generally circular circumference with pins received in radial blind bores whose axes lie in a common radial plane and being rotatably received within an outer part of the double cylinder lock, the generally circular circumference of the plug being flattened in a region immediately to one side of the common radial plane, the plug being rotatable by a key in the direction that moves the flattened region of the plug into the region previously occupied by the pins. In an embodiment of the invention described below the axial range of the flattened region is limited and only one of the pins is within that axial range. It is also possible, however, for the axial range of the flattened region to be greater so that more than one or even all of the pins are within that axial range.

Conveniently, the further cylinder lock is able to be operated by a key from the first side of the lock to move the bolt of the further cylinder lock from the unlocked condition to the locked condition. Also, the further cylinder lock is preferably able to be operated by the thumb turn from the second side of the lock to move the bolt of the further cylinder lock from the unlocked condition to the locked condition.

Preferably, the bolt of the latch arrangement is resiliently biased towards the locked condition.

The double cylinder lock preferably includes a locking member for deadlocking the bolt in the locked condition, the locking member being released upon initial operation of a key in the lock to move the bolt from the locked condition to the unlocked condition. The locking member is preferably also arranged to deadlock the bolt in the unlocked condition, the locking member being released upon - 6 initial operation of a key in the lock to move the bolt from the unlocked condition to the locked condition.

Similarly, the further cylinder lock preferably includes a locking member for deadlocking the bolt in the locked condition, the locking member of the further cylinder lock being released upon initial operation of a key in the lock or of the thumb turn to move the bolt from the locked condition to the unlocked condition. The locking member of the further cylinder lock is preferably also arranged to deadlock the bolt in the unlocked condition, the locking member of the further cylinder Lock being released upon initial operation of a key in the lock or of the thumb turn to move the bolt from the unlocked condition to the locked condition.

The bolt of the further latch arrangement is preferably positioned between the bolts of the double cylinder lock and the further cylinder lock.

The bolt of the double cylinder lock may be provided above the bolts of the further cylinder lock and the further latch arrangement.

The invention is particularly suited to mortise locks.

Usually, the lock of the invention wl11, in use, be fitted to a door and doorway in a building. Accordingly, the invention further provides a door and doorway including a lock as defined above fitted thereto.

By way of example an embodiment of the invention will now be described with reference to the accompanying drawings, of which: - 7 Figure la is a side view of a lock, Figure lb is an end view of a keeper of the lock of Figure la, Figure 2 is an end view of the lock of Figure 1 with the keeper of Figure lb shown next to the lock, Figure 3 is a side view of the lock of Figure la with a side cover of the lock removed, Figure 4a is a view in the same direction as Figure 2 of a first cylinder lock incorporated in the lock of Figure la, Figure 4b is a view of the first cylinder lock viewed in a direction opposite to the direction of viewing of Figure la, Figure 5 is a sectional view along the lines V-V of Figure 4a, Figure 6a is a view in the same direction as Figure 2 of a second cylinder lock incorporated in the lock of Figure la, and Figure 6b is a view of the second cylinder lock viewed in a direction opposite to the direction of viewing of Figure la.

Referring first to Figs. la and lb, there is shown a lock generally comprising a keeper plate 1, a double cylinder lock 2, a further cylinder lock with thumb turn 3 and a springbolt latch 4.

The double cylinder lock 2 is generally of a kind known per se and is shown also in Figs. 2, 3, 4a, 4b and 5.

The double cylinder lock 2 is able to be operated by a key from either side of the lock. In Fig. 4a, a key 50 is shown inserted in a cylinder 2a on a first side of the lock. The left hand side of the lock (as seen in Fig. 9a) and referred to above as the second side of the lock is the side of the lock that is to be on the inside when the lock is fitted to a door.

In accordance with known practice, the cylinder 2a of the double cylinder lock 2 receives respective cylindrical plugs 6 on each of its opposite sides. In Fig. 4b, the plug 6 on the inside of the lock can be seen: the plug 6 is of generally circular cross-section and is rotatably mounted within the cylinder 2a, being able to be rotated when a key is correctly fitted into the plug.

Also shown in Figs. 4a and 4b is a cam 7, which has a main body 7a interposed between and coaxial with the plugs 6 and a protrusion 7b projecting radially from the body 7a. Rotation of one of the plugs 6 by a key 50 correctly inserted into one side of the lock is effective to rotate the cam 7 and operate the lock. The cylinder 2a of the lock includes a slot 8 within which the protrusion 7b is received in one particular rotational position of the lock. In that orientation the protrusion 7b is contained within the volume of a lower portion of the cylinder 2a and does not therefore impede axial sliding movement of the cylinder 2a. On the other hand in the position of the protrusion 7b shown in Fig. 9b, it can be seen that the protrusion 7b projects outwardly from the 9 - cylinder 2a and does impede such sliding movement. A retaining screw 9 (Fig. 3) is screwed into a threaded hole 10 in the middle of the lower portion of the cylinder 2a to retain the cylinder 2a in its correct axial position.

Also in accordance with known practice there is a clutch (not shown) within the cam 7 which IS brought into operation by pressure from the tip of a key as it enters one of the plugs of the lock. The pressure of the key serves to disengage the cam 7 from the plug which does not receive the key thereby enabling the cam 7 to rotate without that plug (which is locked against rotation in the absence of an inserted key) rotating.

As can be seen in Fig. 3, the double cylinder lock 2 has a bolt 2c, shown in Fig. 3 in the deadlocked and locked condition. A bolt lath 2d integral with the bolt 2c is formed with a recess 2e in which, in the deadlocked condition shown in Fig. 3, a locking stump 5a of a detainer S is received. The locking stump Sa is riveted to the detainer and extends at right angles thereto. A torsion spring 11 bears against the detained 5 and biases the locking stump 5a into the position shown in Fig. 3 where it prevents movement of the bolt 2c out of the locked condition.

The double cylinder lock as described above is of a form known per se and operates in a manner known per se: when the lock is in the locked condition shown in Fig. 3, a key 50 may be inserted into either of the plugs 6 to move the bolt 2c to a retracted condition. Assuming the correct key is inserted then the pins and drivers are positioned to allow rotation of the plug 6 and, consequently, of the cam 7. Initial rotation of the cam 7 moves the locking stump 5a out of the recess 2e of the bolt lath 2d against the bias of the spring 11. Further rotation of the cam 7 causes the protrusion 7b on the cam to engage a dove surface 2f on the bolt lath 2d and move the bolt lath 2d to the right (as seen in Fig. 3) retracting the bolt 2c into the interior of the lock defined by a lock casing 12.

The double cylinder lock 2 departs from conventional design in a respect that will now be described with reference to Fig. 5 which is a sectional view through a region of the double cylinder lock on the inside. Fig. 5 shows the cylinder 2a and the plug 6 rotatably mounted within the cylinder. The plug 6 has a keyway 14 and is formed, in a manner known per se, with a series of radial blind bores 15 in which pins 16 are slidably received. The sectional view of Fig. 5 passes through one such blind bore 15. Similarly, the cylinder 2a is formed with a series of bores 17 in which drivers 18 are slidably received, the drivers 18 each being resiliently biased towards the pins 16 by springs 20 and aligned with the pins 16. Thus the section of Fig. 5 passes through one such bore 17. As will be understood, in the absence of a key in the keyway the driver 18 shown in Fig. 5 is received partly in the bore 17 but also partly in the bore 15 and - 11 therefore prevents rotation of the plug 6 within the cylinder 2a.

The plug 6, lostead of having an exterior profile of circular cylindrical cross-section has in the axial region of the section of Fig. 5 a flattened region 39 immediately to one side (the right side as seen in Fig. 5) of the radial plane containing the bores 15 and the pins 16.

Furthermore, the pin 16 shown in Fig. 5 and key (not shown in Fig. 5) of the lock are arranged such that when the correct key is inserted, the top of the pin 16 is at the level of the flattened region 19, which is radially inside the circumference of the circular periphery of the plug.

That position of a pin 16 is shown in Fig. 5. As can be seen from the drawing, the driver 18 projects a small distance into the plug 6 as a result of the level of the top of the pin 16. Consequently the driver 18 prevents rotation of the plug 6 in an anticlockwise direction (as seen in Fig. 6) as a result of engagement of the driver with a portion 6a of the plug. On the other hand, if the plug 6 is rotated in a clockwise direction (as seen in Fig. 6), the flattened region 19 slides under the end face of the driver 18 and cammingly engages it pressing it back into its bore 17. Thus with the correct key inserted, the plug 6 can be turned clockwise (as seen in Fig. 6) but not anticlockwise (as seen in Fig. 6). The lock is arranged such that clockwise rotation (as seen in Fig. 6) corresponds to unlocking the lock and anticlockwise rotation (as seen in Fig. 6) corresponds to locking the - 12 lock. In that way a double cylinder lock that can be unlocked from either side but locked only from the outside is provided. Whilst in the illustrated embodiment, the special arrangement of pin, driver and flattened region is provided for only one pin, it will be understood that, if desired, the axial range of the flattened region can be increased and more or all of the pins and drivers arranged as just described.

The further cylinder lock with thumb turn 3 is of a kind known per se and, apart from the provision of a thumb turn, indicated by reference numeral 21 in place of a second cylinder lock, and the absence of a special feature to prevent the thumb turn both locking and unlocking the lock, is generally of the same design as the double cylinder lock 2. In the drawings parts of the further cylinder lock 3 that correspond to parts of the double cylinder lock 2 are referenced by the same numeral with 100 added thereto. Thus the further cylinder lock is shown having a cylinder 102a, a bolt 102c, a bolt lath 102d with a recess 102e and a detained 105 with a locking stump 105a.

A spring 111 biases the detained 105 into the deadlocking position. The cylinder 102a houses a cylinder plug 106 on its outer side and has a cam 107 with a body 107a and a radially projecting protrusion 107b which can be accommodated within a slot 108. A retaining screw 109 is screwed into a threaded hole 110 to retain the cylinder 102a in its correct axial position. The plug 106 has pins 116 in blind bores 115 and drivers 118 in - 13 bores 117 biased by springs 120. The thumb turn 21 Is of a kind known per se and as shown in Fig. 6a is rotatably, and axially slidably, coupled to an intermediate driving member 22 which engages the cam 107 via the clutch 23.

Reference numeral 24 in Fig. 6a designates the clutch spring.

The springbolt latch 4 is also of a kind known per se and is shown in Fig. 3. The latch includes a springbolt 30 that is slidably mounted and resiliently biased to its extended, latching, position by a further arm of the same torsion spring 11 as bears against the detained 5 of the double cylinder lock 2. A follower 31 is rotatably mounted in the lock casing 12 and has a square through passageway 32 for receiving the shaft of a lever handle (now shown). The follower 31 is biased against movement in a clockwise direction (as seen in Fig. 3) by a compression spring 33. Thus operation of the lever handle (depression of the handle) is effective to rotate the follower 31 against the bias of the spring 33 and cause a projecting part 31a of the follower to cammingly engage the lath of the springbolt 30 and retract the springbolt 30 against the bias of the torsion spring 11. On releasing the handle the torsion spring 11 returns the springbolt 30 to the extended, latching, position shown in Fig. 3 and the compression spring 33 returns the follower 31 (and lever handle) to the position shown in Fig. 3. If the door is closed without operation of the lever handle the springbolt 30 is pressed inwardly by the keeper plate 1 against the bias of the spring 33 while the follower 31 (and lever handle) do not move. Once the door reaches the closed position, the springbolt 30 is then able to enter into an opening 41 in the keeper plate 1 and does so as a result of the bias of the spring 33.

In addition to the opening 41 for the springbolt 30, the keeper plate l has a bottom opening 42 for the bolt 2c of the double cylinder lock and a top opening 43 for the bolt 102c of the further cylinder lock with thumb turn 3.

The inside edges 41a, 42a and 43a of the openings in the keeper define the faces (referred to herein as the locking faces) of the keeper which engage opposing faces of the bolts of the locks in the locked condition. The opposing faces of the bolts 2c, 102c and 30 and the edges 41a, 42a, and 43a are positioned such that when the springbolt 30 is in the latched condition and thus engaging the edge 41a of the keeper plate 1, the bolts 2c and 102c are slightly spaced from the edges 42a and 43a. Thus with the springbolt 30 in the latched condition, there is no frictional resistance applied by the keeper plate 1 to retraction of the bolts 2c and 102c. As will be understood this offset positioning of the bolts and the openings in the keeper plate may be achieved by offsetting of the openings in the keeper plate 1 and/or offsetting of the positions of the bolts.

As will now be understood, the lock shown in the drawings can be used to secure an exterior door of a building in a manner which enables the building to be kept secure but also allows occupants to escape from the building. When the building is unoccupied both the double cylinder lock 2 and the further cylinder lock with thumb turn 3 can be locked from the outside. In that case, even if an intruder gains access to the inside of the building, a key is still required in order to unlock the double cylinder lock 2 and security is therefore maintained. When a person enters the building by unlocking the locks, it is then a simple matter for the person to lock the further cylinder lock using first the thumb turn and then the lever handle of the latch 4. In the event of fire a person can escape quickly simply by turning the thumb turn and easy turning of the thumb turn is assured because the springbolt 30 of the latch 4 keeps the bolt 102c of the lock clear of the keeper plate 1 even if, for example as a result of door seals, there is substantial pressure of the lock on the keeper plate. Furthermore, the occupant is unable to deprive himself or herself of such easy escape by locking the double cylinder lock 2 because that cannot be locked from the inside.

Claims

Claims: 1. A lock including: a double cylinder lock able to be operated by

a key from either side of the lock to move a bolt of the double cylinder lock from a locked condition to an unlocked condition; a further cylinder lock able to be operated by a key from a first side of the lock to move a bolt of the further cylinder lock from a locked condition to an unlocked condition, and able to be operated by a thumb turn from the second, opposite, side of the lock to move the bolt of the further cylinder lock from the locked condition to the unlocked condition; and a latch arrangement able to be operated manually from both sides of the lock to move a bolt of the latch arrangement from the locked condition to the unlocked condition, the bolts of the double cylinder lock, the further cylinder lock and the latch arrangement being arranged in a keeper such that, when the bolt of the latch arrangement is in the keeper, the bolt of the double cylinder lock and the further cylinder lock are prevented from pressing against the keeper in a direction towards said second side of the lock.
2. lock according to claim 1, in which inner faces of portions of the bolts of the double cylinder lock and the further cylinder lock are offset towards said first side of the lock from an inner face of the bolt of the latch arrangement.
3. A lock according to claim 1 or 2, in which the keeper of the lock is provided with respective locking faces for engaging the bolts of the double cylinder lock, the further cylinder lock and the latch arrangement to prevent movement of the bolts when they are in the locked condition towards the second side of the lock, the locking faces for engaging the bolt of the double cylinder lock and for engaging the bolt of the further cylinder lock being offset towards the second side of the lock from the locking face for engaging the bolt of the latch arrangement.
4. A lock according to any preceding claim, in which the double cylinder lock is also able to be operated by a key from the first side of the lock to move the bolt of the double cylinder lock from the unlocked condition to the locked condition, but a blocking arrangement is provided for blocking movement of the bolt of the double cylinder lock from the unlocked condition to the locked condition through operation of a key from said second side of the lock.
5. A lock according to claim 4 in which a key inserted into the double cylinder lock from said second side of the lock is able to be turned from its initially inserted position in one direction only.
6. A lock according to claim 5, in which the double cylinder lock includes an inner plug on the second side of the lock, the inner plug having a generally circular - 18 circumference with pins received in radial blind bores whose axes lie in a common radial plane and being rotatably received within an outer part of the double cylinder lock, the generally circular circumference of the plug being flattened in a region immediately to one side of the common radial plane, the plug being rotatable by a key in the direction that moves the flattened region of the plug into the region previously occupied by the pins.
7. A lock according to any preceding claim in which the further cylinder lock is able to be operated by a key from the first side of the lock to move the bolt of the further cylinder lock from the unlocked condition to the locked condition.
8. A lock according to any preceding claim, in which the further cylinder lock is able to be operated by the thumb turn from the second side of the lock to move the bolt of the further cylinder lock from the unlocked condition to the locked condition.
9. A lock according to any preceding claim, in which the bolt of the latch arrangement is resiliently biased towards the locked condition.
10. A lock according to any preceding claim in which the double cylinder lock includes a locking member for deadlocking the bolt in the locked condition, the locking member being released upon initial operation of a key in the lock to move the bolt from the locked condition to the unlocked condition. 19
11. A lock according to claim 10, In which the locking member is also arranged to deadlock the bolt in the unlocked condition, the locking member being released upon initial operation of a key in the lock to move the bolt from the unlocked condition to the locked condition.
12. A lock according to any preceding claim, in which the further cylinder lock includes a locking member for deadlocking the bolt in the locked condition, the locking member of the further cylinder lock being released upon initial operation of a key in the lock or of the thumb turn to move the bolt from the locked condition to the unlocked condition.
13. A lock according to claim 12, in which the locking member of the further cylinder lock is also arranged to deadlock the bolt in the unlocked condition, the locking member of the further cylinder lock being released upon initial operation of a key in the lock or of the thumb turn to move the bolt from the unlocked condition to the locked condition.
14. A locking member according to any preceding claim, in which the bolt of the further latch arrangement is positioned between the bolts of the double cylinder lock and the further cylinder lock.
15. A lock according to any preceding claim, in which the bolt of the double cylinder lock is provided above the bolts of the further cylinder lock and the further latch arrangement. -
16. A lock according to any preceding claim, the lock being a mortise lock.
17. A lock substantially as herein described with reference to the accompanying drawings.
18. A door and door frame including a lock according to any preceding claim fitted thereto.