GB2424031A - Deadbolt lock with pivoted pushing member - Google Patents

Abstract

A lock (10) is disclosed. The lock (10) comprises a lock case (20); a deadbolt (30) arranged to be extended from and retracted into the lock case (20) and an arm (40) connected to the deadbolt (30) to push the deadbolt (30) into an extended position. The arm (40) is pivoted (31) and arranged to be rotated about the pivot (31) into alignment with and connected to a component (51) rigidly mounted in the lock case (20) or the lock case itself, when the deadbolt (30) is in the extended position. Rotation of the arm allows an increased force to be applied to the deadbolt (30) and prevents it from being pushed back into the lock case (20) when extended. The lock (10) may be provided with an electrically powered means and a mechanically operated means, either of which is actuatable to move the arm and the deadbolt (30) into an extended position via thrower pins (53) mounted on a thrower (50) pivoted about the component (51).

Description

The present invention relates to a lock, in particular a lock with a

deadbolt to be moved to secure a door for example.

Locks may be provided in a mortice in a door. A deadbolt mounted in the lock is capable of extension from a front face of the lock by mechanical or electrical means and is locked in engagement with a locking plate morticed in a door jamb. The mechanical or electrical means is also capable of withdrawing the bolt from the locking plate. The mechanism can also be adapted for use in other circumstances for example in a rim lock mounted to the inside face of a door with the deadbolt engaging a suitable locking plate mounted on the jamb or in a drawer for example.

To comply with various national standards, the movement of the deadbolt into the extended position into engagement with a locking plate must be capable of overcoming a defined resistance. The ability to extend the deadbolt with at least a minimum force may be required to overcome an obstruction in the locking plate or misalignment between the lock and the locking plate for example. It would be desirable to be able to move the deadbolt into the extended position with a greater force in order to overcome an obstruction or misalignment.

It is sometimes possible for the deadbolt to be pushed from outside the lock case from it's extended position back into the lock case to it's withdrawn position to the unlocked state.

It is an aim of an embodiment of the present invention to be able to extend the deadbolt with a sufficient force and to make it more difficult for the extended deadbolt to be pushed into the lock case.

According to a first aspect of the present invention there is provided a lock comprising a lock case; a deadbolt arranged to be extended from and retracted into the lock case and an arm connected to the deadbolt to push the deadbolt into an extended position; wherein the arm is pivoted and arranged to be rotated about the pivot into alignment with and connection to a component rigidly mounted in the lock case or the lock case itself when the deadbolt is in the extended position.

Rotation of the arm into alignment with and connection to a component rigidly mounted in the lock case or the lock case itself enables the arm to push the deadbolt into its extended position with an increased force and prevents the deadbolt from being pushed back into the lock case.

The pivot is preferably provided at the point at which the arm is connected to the deadbolt.

A bolt thrower is preferably rotatably mounted on a shaft rigidly mounted on the lock case, with the bolt thrower being provided with a number of elements to engage the arm such that rotation of the bolt thrower moves the arm to push the deadbolt into an extended position and further rotation of the bolt thrower rotates the arm about its pivot at its connection to the deadbolt to align the pivot, the element of the bolt thrower engaging the arm and the shaft upon which the bolt thrower is rotatably mounted. The pivot, the element of the bolt thrower engaging the arm and the shaft upon which the bolt thrower is provided preferably form a toggle joint.

The lock is preferably provided with an electrically powered means and a mechanically operated mechanism, either of which may be actuated to move the arm and the deadbolt to an extended position. The mechanically operated mechanism is preferably actuated by rotating a key to be inserted into the lock.

Although mechanical key mechanisms with high resistance to various forms of attack are available, if a key is lost or stolen the key mechanism must be changed to maintain the security of the door. Such key mechanisms are costly and calling out a locksmith or competent person to change the cylinder is expensive and may not be immediately possible, leaving the premises vulnerable and possibly without insurance cover. The provision of an electrically powered means and a mechanically operated mechanism, either of which may be actuated to move the arm and the deadbolt to an extended position enables the lock to be secured by the electrically powered means if a key is lost or stolen maintaining the security of the door.

The electrically powered means is preferably operated to lock or unlock a door by an access control system, such as a proximity reader to detect the presence of a proximity token or a keypad for example. A lost or stolen proximity token may be made inoperative by a simple programming operation without affecting use of the remaining tokens. A disclosed access code may be dealt with by reprogramming the keypad to require a new input.

In normal industry practice a control system is installed remotely from the locking device with power supplied from the electrical means via a transformer. An illicit connection may be made to the wiring to activate the locking device and the wiring, control system and power supply are often highly vulnerable to attack and vandalism.

In a preferred form of the present invention the access control system and power supply, such as a battery, are mounted within the lock case. They may be protected against attack by hardened steel plates to minimise installation complexities and comply with insurance company requirements for final exit door locks.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figures Ia to if show the electrical operation of a lock in which a deadbolt is gradually extended from the lock case; Figure 2a to 2d shows the mechanical operation of the lock; Figure 3 shows a cover provided over the lock case; and Figure 4 shows a drill resistant plate provided over the cover.

Figures Ia to If show the electrical operation of a lock 10 to extend a deadbolt 30. For clarity some mechanically operated components of the lock 10 are omitted from the views of Figures 1 a to 1 f.

The lock 10 is provided in a lock case 20 and is arranged to extend and retract the deadbolt 30 from the lock case 20. A locking arm 40 is connected to the deadbolt to push the deadbolt 30 into an extended position (Figure If) and to pull the deadbolt 30 into a retracted position (Figure Ia). The locking arm 40 is pivoted at its connection 31 to the deadbolt 30 and is rotated about the pivot 31 into alignment with and connection to a bolt thrower 50 rigidly mounted in the lock case 20 when the deadbolt 30 is in the extended position (Figure If). Rotating the locking arm 40 at pivot connection 31 creating a toggle joint, magnifies the force applied to finally move the deadbolt 30 to the extended position and locks the deadbolt 30 in place.

The lock 10 shown in Figure la is arranged to be fitted into a mortice in a door (not shown) and has a forend 60 on one side through which the deadbolt 30 extends when in use. In use a plate which is preferably drill resistant is fitted to each side of the lock 10. The deadbolt 30 extends in use into a corresponding locking plate in a doorjamb.

The lock 10 shown in Figure la has an electric motor 70 connected to a gearbox 80 pivotally mounted in the lock 10. A worm gear (not shown) is mounted to the motor shaft and meshes with a worm wheel 81 mounted on a shaft in the gearbox 80. A pinion 82 is concentrically mounted on the gearbox worm wheel shaft and permanently connected to the worm wheel 81 on the gearbox worm wheel shaft.

A motor control board 90 is provided with switches 91, 92 to control rotation of the motor 70 in the desired direction.

The bolt thrower 50 is rotatably mounted on a bolt thrower stump 51 rigidly mounted in the lock case 20. A bolt thrower gear wheel 52 is mounted on the bolt thrower stump 51 and fixed relative to the bolt thrower 50. The bolt thrower gear wheel 52 is normally in mesh with the gearbox pinion 82.

The bolt thrower 50 is constructed as two discs mounted through their centres on the bolt thrower stump 51 and spaced apart along the length of the bolt thrower stump 51 separated by a spacer (not shown). Pins 53 are provided between the two discs and are mounted substantially parallel to the bolt thrower stump 51.

The deadbolt 30 is slidably mounted in the lock 10 with the locking arm 40 mounted at pivot 31 to the deadbolt. The locking arm 40 has a series of gaps or gatings 41 along one edge to engage the pins 53 of the bolt thrower 50.

The deadbolt 30 is retained in its initial retracted position as shown in Figure la by the abutment of a first bolt thrower pin 53 against a radial face in a first gating 41 of the locking arm 40.

Figures lb to 1 d show views of the bolt thrower 50 rotated by operation of the motor 70 and gearbox 80. The bolt thrower pins 53 successively engage the locking arm gatings 41 to move the locking arm 40 and deadbolt 30 toward a second extended position.

Figure le shows the deadbolt 30 approaching the second extended position, with final movement to the second position made by the interaction of the third bolt thrower pin 53 against the end face of the locking arm 40. Further rotation of the bolt thrower 50 engages the third bolt thrower pin 53 in a form 42 in the end face of the locking arm 40. The locking arm 40 is rotated about the pivot connection 31 between the deadbolt 30 and the locking arm 40 creating a toggle joint to increasingly magnify the force applied to finally move the deadbolt 30 to the second position. The magnified effort may be required to overcome an obstruction in a locking plate into which the deadbolt 30 is provided or misalignment between the lock 10 and the locking plate for example.

A first microswitch 91 provided on motor control board 90 is operated by the final movement of the deadbolt 30 to switch current off to the motor 70 and maintain the final position of the bolt thrower pins 53.

Figure lf shows the deadbolt 30 in a second, extended position. The elements of the toggle joint, i.e. the pivot point 31 of the locking arm 40 in the deadbolt 30, the pivot point of the bolt thrower pin 53 in the end form 42 of the locking arm 40 and the centre of the bolt thrower stump 51 are rotated into alignment to maintain the deadbolt in a second position and resist force applied to the end of the deadbolt 30 in a attempt to force the deadbolt 30 towards the initial first position shown in Figure la.

The bolt thrower 50 is locked against rotation when the deadbolt 30 is extended, in this example by the gear train being locked by the pitch of the worm gear precluding rotation of the worm by pressure applied to the worm wheel 81.

It will be seen that reversing the direction of motor rotation will rotate the bolt thrower pins 53 to return the locking arm 40 to the retracted position. Further rotation of the bolt thrower 50 moves the third bolt thrower pin 53 to contact a face on a pull- back arm 43 and move the deadbolt 30 towards the initial first position as shown in Figure la.

The deadbolt 30 is moved fully to the retracted first position by interaction of the bolt thrower pins 53 and locking arm gatings 41. A second microswitch 92 also provided on motor control board 90 is operated by the final movement of the deadbolt to switch current off to the motor 70 and maintain the first bolt thrower pin 53 in abutment with the radial face of the first gating 41.

The lock 10 shown in Figures Ia to If is preferably provided with an access control system. The access control system may take the form of a proximity reader to detect the presence of proximity tokens to lock and unlock a door or a digital keypad into which an appropriate code is to be entered to lock and unlock a door.

In a preferred form the access control system is produced as part of the circuitry on the motor control board 90 with a suitable digital key pad or reader mounted to the external face of the door. Alternatively the electronic signal may be provided by an access control system installed remotely from the lock 10.

Connections to the motor control board 80 may be made by wires run through the door thickness or by wire-free radio transmissions.

In a preferred form power for operation of the access control system and motor is supplied by batteries mounted in the lock 10. Alternatively, especially if the lock is controlled by a wire-connected remote access control system, power may be supplied by that system.

Figures 2a to 2d show the mechanical operation of the lock 10. In the views of Figures 2a to 2d runner 100 and tumbler 110 are included. These features were omitted from Figures Ia to if for clarity in the description of the electrical operation of the lock 10.

Figure 2a shows the lock 10 in an unlocked state with the deadbolt 30 retained within the lock case 20.

A runner 100 with gear teeth 101 is slidably mounted to the lock 10 with the gear teeth 101 on the runner 100 permanently in mesh with a bolt thrower pinion 54.

The bolt thrower pinion 54 is concentrically mounted to the bolt thrower shaft 51 and permanently connected to the bolt thrower 50. A tumbler 110 is slidably mounted to the lock 10 and operatively connected to the gearbox 80. A lock cylinder 120 with a cylinder cam 121 is mounted to the lock 10 and secured by a cylinder fixing screw 122.

Figure 2b shows a key 123 inserted in the cylinder 120. Rotation of the key 123 moves the cylinder cam 121 into engagement with a face on the tumbler 110.

Further rotation of the cylinder cam 121 moves the tumbler 110 to a lifted position and engages the cylinder cam 121 in a gating 102 in the runner 100. The movement of the tumbler 110 to the lifted position rotates the gearbox 80 to disengage the worm wheel pinion 82 from the bolt thrower gear wheel 52 and enable rotation of the bolt thrower 50.

in Figure 2c the cylinder cam 121 is further rotated. Engagement of the cylinder cam 121 in the runner gating 102 causes rotation the runner 100 and bolt thrower 50. The rotation of the bolt thrower 50 and bolt thrower pins 53 moves the locking arm 40 and deadbolt 30 towards a second position.

Figure 2d shows the runner 100 and deadbolt 30 moved fully to the thrown position with the locking arm 40 pivoted at its connection 31 to the deadbolt 30 such that it is rotated about the pivot 31 into alignment with and connected to the bolt thrower 50 which is rigidly mounted in the lock case 20 via the bolt thrower stump 51.

The elements of the toggle joint are aligned as in the electrical operation described in Figures 1 a to If. As the cylinder cam 121 is further rotated, the differing operational radii of the runner 100 and cylinder cam 121 allow the cylinder cam 121 to leave the runner gating 102. The tumbler 110 and gearbox 80 return to their original positions and the worm wheel pinion 82 re-engages the bolt thrower gear wheel 52 to prevent rotation of the bolt thrower 50 from the second position.

It will be seen that rotating the cam 121 in a reverse direction will lift the tumbler 110 and propel the runner 100 and deadbolt 30 to the first positions shown in Figure 2a.

Figure 3 shows a cover 200 provided over the lock case 20 with arcuate holes 201 to receive pins 103 provided on the runner 100 and with a number of holes 202 to receive screws.

Figure 4 shows a drill resistant plate 300 fitted over the cover 200 with a number of screws 301 provided in the holes 202 of the cover 200. A drill resistant plate 300 is also fitted to the other side of the lock case 20.

Claims (13)

1. A lock comprising a lock case; a deadbolt arranged to be extended from and retracted into the lock case and an arm connected to the deadbolt to push the deadbolt into an extended position wherein the arm is pivoted and arranged to be rotated about the pivot into alignment with and connected to a component rigidly mounted in the lock case or the lock case itself when the deadbolt is in the extended position.

2. A lock according to claim I, wherein the pivot is provided at the point at which the arm is connected to the deadbolt.

3. A lock according to claim 2, further comprising a bolt thrower rotatably mounted on a shaft rigidly mounted to the lock case, the bolt thrower having a number of elements to engage the arm such that rotation of the bolt thrower moves the arm to push the deadbolt into an extended position and further rotation of the bolt thrower rotates the arm about its pivot at its connection to the deadbolt to align the pivot, the element of the bolt thrower engaging the arm and the shaft upon which the bolt thrower is rotatably mounted.

4. A lock according to claim 3, wherein the pivot, the element of the bolt thrower engaging the arm and the shaft upon which the bolt thrower is provided form a toggle joint.

5. A lock according to any one of the preceding claims, provided with an electrically powered means and a mechanically operated mechanism, either of which is actuatable to move the arm and the deadbolt into an extended position.

6. A lock according to claim 5, wherein the mechanically operated mechanism is actuatable by rotation of a key.

7. A lock according to claim 5 or claim 6, wherein the electrically powered means is driven by an electric motor.

8. A lock according to any one of claims 5 to 7, wherein the electrically powered means is operated to lock or unlock a door, in use, by an access control system.

9. A lock according to claim 8, wherein the access control system is a proximity reader to detect the presence of a proximity token.

10. A lock according to claim 8, wherein the access control system is a keypad into which a predetermined code must be entered to operate the access control system.

11. A lock according to any one of claims 8 to 10, wherein the access control system and an electrical power supply are mounted within the lock case.

12. A lock according to claim 11, wherein the lock case is provided with metal plates.

13. A lock substantially as hereinbefore described with reference to the accompanying drawings.