NZ602326B - Electromechanical drop bolt - Google Patents

Abstract

Electromechanical Drop Bolt This invention relates to an electromechanical bolt assembly 1 which allows for adjustment of its mode of operation between a fail safe mode and a fail secure mode with a manual override feature. The assembly I includes a housing 3 with a bolt 4 movable relative to the housing 3. The assembly 1 also includes a powered drive 29, a powered actuator 26 and a key operated actuator 25, all operable for moving the bolt 4 relative to the housing 3. ousing 3. The assembly 1 also includes a powered drive 29, a powered actuator 26 and a key operated actuator 25, all operable for moving the bolt 4 relative to the housing 3.

Description

RECEIVED at IPONZ on 23 November 2012 ELECTROMECHANICAL DROP BOLT FIELD OF THE INVENTION This invention relates to an electromechanical bolt assembly for use in securing a door panel in a closed position relative to a door frame. The bolt assembly is designed to allow adjustment of its mode of operation between a fail safe mode and fail secure mode, and with an ability to manually override the function of the bolt assembly in the event of a power failure.

BACKGROUND OF THE INVENTION Traditionally a drop bolt included a rod mountable to an inside surface of a door panel. A user will grasp the rod and slide it relative to the door panel in order to locate a tip of the rod in a recess located in the door frame adjacent the top or bottom edge of the door panel. The drop bolt provides a relatively simple solution for securing the position of a door panel, once it is located in a closed position.

A traditional drop bolt is a popular security solution for double doors. It is generally not intended that the bolt be manipulated every time a user wants to open the door, as say with a door latch. Rather it is preferable that the tip be located in the recess only when access through the door will not be required for an extended period of time. A problem with the traditional the drop bolt is that the location of the bolt allows it to be moved by unauthorised personal.

One option is to provide a bolt assembly having an electromechanical actuator to move the bolt relative to a housing, and concealing the assembly in the door panel. This type of assembly can include a solenoid for causing rectilinear movement of the bolt between an extended and retracted position relative to the housing. Naturally power is required by the solenoid to operate, and control of the actuator will require remote activation. An access control system including for example an electronic card reader which verifies credentials of the user may also be required. drop bolt.doc It will be appreciated that in the bolt assembly will be inoperable in the event of a power failure to any one of the foregoing components. This could result in the bolt being left in an extended position thereby securing the door in a closed position. This could present a safety problem if the user of the premises requires emergency access from the premises. Alternatively a power failure may leave the bolt in a retracted position, leaving the door free to be opened.

This may present a security problem if prevention of unauthorised access to the premises is required.

The configuration of some bolt assemblies can be adjusted to suit the prevailing safety/security requirements for the premises where the bolt assembly is installed. The selection generally involves adjusting elements of the bolt assembly and those elements are obstructed by the panel once the bolt assembly is installed. Accordingly the selection is relatively permanent for so long as the bolt assembly remains in the door panel.

This can present a problem if the safety/security requirements for the premises change. This may occur where the bolt assembly is installed in commercial premises, and the tenants change. The tenants may be unable to secure the services of a locksmith to adjust the mode of operation of the bolt assembly before use of the premises is required.

A further problem can arise where the operation of the bolt assembly is centrally controlled from a location remote from the premises. The user of the premises may be unable to communicate effectively with the central controller, and the selected safety/security requirements may be temporarily inappropriate.

A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in New Zealand, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

According to this invention there is provided an electromechanical bolt assembly for securing a door panel in a closed position relative to a door frame, drop bolt.doc the bolt assembly including a housing, a bolt movable relative to the housing between an extended position and a retracted position, a movable member that is movable within the housing between a first position and a second position, the movable member being associated with the bolt so that the bolt adopts a retracted position when the movable member is in the second position, a powered drive that is operable to adjust the position of the movable member from the second position to the first position and operable to move the bolt from the retracted position to the extended position, a powered actuator for controlling movement of the movable member from the first position to the second position, the powered actuator being operable in a fail safe mode or a fail secure mode whereby in the event of a power failure to the bolt assembly with the powered actuator in the fail safe mode the bolt adopts the retracted position and in the fail secure mode the bolt adopts the extended position, a key operated actuator being operable to adjust the position of the bolt from the extended position to the retracted position.

It is preferred that the key operated actuator is operable to adjust the position of the movable member from the first position to the second position to adjust the position of the bolt from the extended position to the retracted position.

The powered drive may be separate from the movable member however it is preferred that the powered drive is associated with the movable member so as to move therewith in the housing between a first position and a second position.

The movable member preferably slides within the housing, and further includes a biasing means for biasing the movable member so as to urge the movable member to adopt the second position.

It is preferred that the electromechanical bolt assembly be configured to for the mode of the powered actuator is adjustable from outside the housing.

It is preferred that the powered actuator includes a solenoid having a plunger that is movable relative to a body of the plunger against a bias on energisation of the actuator, a position of the solenoid within the housing being adjustable for adjusting the mode of the powered actuator and the position of the solenoid being adjustable by adjustment of a captured screw. drop bolt.doc It is further preferred that the electromechanical bolt assembly include a detent that is adjustable between a release condition and a retain condition by operation of the powered actuator, the detent interacts with the movable member whereby in the event of power failure and the powered actuator is in the fail secure mode the movable member is retained in the first position, and when the powered actuator is in a fail safe mode the movable member is released to adopt the second position. It is further preferred that the electromechanical bolt assembly include a adjustable catch associated with the moveable member which is adjustable from outside of the housing when adjusting the mode of the powered actuator. It is still further preferred that the key operated actuator is operable to adjust the condition of the detent. The key operated actuator preferably includes a cylinder lock having a cam that is rotatable from a standby position by use of an authorised key. The key operated actuator may interact with any feature of the assembly however it is preferred that it includes a follower that interacts with the cam and detent for adjusting the position of the detent. It is preferred that the follower is biased away from interacting with the detent. The preferred form of follower includes a plunger and a compression spring urging the plunger away from interacting with the detent. The plunger preferably includes a wedge that interacts with the detent to move the detent in a direction substantially perpendicular to a direction of movement of the plunger. It is preferred that the key operated actuator is operable to adjust a switch that is adjustable between an open condition and a closed condition, so that when the switch adopts an open condition the bolt is moved from the extended position to the retracted position. It is preferred that the switch is retained in the closed condition by the cam when the cam is in the standby position. It is preferred that the switch is biased to adopt an open condition so that when the cam is rotated from the standby position it causes the switch to adjust from the closed condition to the open condition. It is preferred that the switch is operably connected to the powered actuator so that adjusting the switch from closed condition to the open condition causes the powered actuator to respond as it there was the event of the power failure.

It is preferred that the bolt is pivotable about a shaft between the retracted position and the extended position. drop bolt.doc It is preferred that the powered drive includes a drive shaft that is rotated to adjust the position of the movable member between the second position and the first position. It is further preferred that the drive shaft is rotatable to move the bolt from the retracted position to the extended position once the movable member is in the first position. It is preferred that the electromechanical bolt assembly include a driven member that is movable along the length of the drive shaft when the drive shaft is rotated. It is further preferred that the bolt interacts with the driven member. It is further preferred that the drive includes an electric motor that is operable to rotate the drive shaft. It is further preferred that An electromechanical bolt assembly according to any one of the preceding claim wherein the housing includes a base and a cover, the mode of the powered actuator being adjustable while the cover is attached to the base.

It will be convenient to hereinafter describe the invention by reference to a particular form of electromechanical bolt assembly including a pivotable bolt.

The following pages of this specification which refer to the accompanying drawings are merely illustrative of how the invention might be put into effect.

The specific form and arrangement of the various features as shown is not to be understood as limiting on the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevation view of an electromechanical bolt assembly according to a preferred aspect of this invention schematically installed in a door way.

Figure 2 is an isometric view of the electromechanical bolt assembly and strike plate from Figure 1.

Figure 3 is a side elevation view of the bolt assembly from Figure 2 with a cover plate of the housing removed.

Figure 4 is a side elevation view of the bolt assembly from Figure 3 with a switching arm removed, a movable member in a first position, and the bolt in extended position. drop bolt.doc Figure 5 is a side elevation view of the bolt assembly from Figure 4 with the movable member moved to a second position with the bolt in a retracted position.

Figure 6 is a side elevation view of the bolt assembly from Figure 5 with the movable member returned to the first position, and the primary powered actuator in an inoperative position.

Figure 7 is a detailed isometric view of a portion of the bolt assembly from Figure 4 with the powered actuator in a fail secure mode and part of the solenoid frame removed to reveal the solenoid plunger.

Figure 8 is a detailed isometric view of a portion of the bolt assembly from Figure 5 with the powered actuator in a fail secure mode and part of the solenoid frame removed to reveal the solenoid plunger.

Figure 9 is a detailed isometric view of a portion of the bolt assembly from Figure 7 with the powered actuator in a fail safe mode and illustrating the solenoid frame.

Figure 10 is a detailed isometric view of the bolt assembly from Figure 9 with part of the solenoid frame removed.

Figure 11 is a detailed isometric view of the bolt assembly from Figure 7 from a different position with a key operated actuator in a standby position.

Figure 12 is a detailed isometric view of the bolt assembly from Figure 11 illustrating the cam engaging the plunger.

Figure 13 is a detailed isometric view of the bolt assembly from Figure 9 from a different position with the key operated actuator in a standby position. drop bolt.doc Figure 14 is a detailed isometric view of the bolt assembly from Figure 13 illustrating the cam engaging the plunger.

DETAILED DESCRIPTION OF THE DRAWINGS Referring firstly to Figure 1 which illustrates a preferred embodiment of the electromechanical bolt assembly 1 installed in a door panel 2. The bolt assembly 1 illustrated in Figure 1 includes a housing 3 with a bolt 4 illustrated in an extended position, extending out a front wall of the housing 3. The bolt 4 interacts with a strike plate 6 which is installed adjacent the door panel when the door is in the closed position as illustrated. It will be appreciated that the housing 3 and strike plate 6 may be swapped so that the housing 3 is located in the door surround 7 and the strike plate 6 installed in the door panel 2.

Figure 1 also illustrates a wire 8 extending out a bottom wall 9 of the housing 3.

When the assembly 1 is installed, this wire 8 is connected to a power source P and control unit C. The control unit C may take any suitable form such as a localised card reader positioned adjacent the door, or a remote high level control authority. When in use the controller C will process the user’s credentials such as a key tag and if access is authorised, communicate with the bolt assembly 1 for adjusting the position of the bolt 4 relative to the housing 3 between an extended position and a retracted position. The manner in which the bolt is moved will be described in greater detail with reference to later illustrations.

Figure 1 also illustrates a cylinder lock 10 having a barrel 11 that is rotatable on insertion of an authorised key (not shown). The cylinder lock 10 interacts with other elements of the bolt assembly 1 in a manner that will be described in greater detail with reference to later illustrations. The cylinder lock 10 is accessible from either side of the door panel 2 when the bolt assembly 1 is installed. It can be appreciated from Figure 2 that the cylinder lock 10 projects out from a cover 12 and a base wall of the housing. It should also be appreciated that the remaining features of the bolt assembly visible on the cover 12 and rear wall 13 of the housing 3 will not be accessible once the bolt assembly 1 is installed in the door panel 2. drop bolt.doc Turning now to Figure 2 and in particular the strike plate 6 which is illustrated as having a V shaped aperture 14 to receive the bolt 4. The movement of the bolt 4 will be explained in more detail later in the specification, however it should be noted that it pivots in a clockwise direction from a retracted position to an extended position. The V shape provides a greater tolerance in alignment to the door 2 with the surround 7 to allow the bolt to enter the aperture as it pivots.

This is particularly useful when the door panel 2 is installed in a surround 7 that does not include a jamb. The arrangement often occurs when there are double doors.

Figure 2 also illustrates the housing 3 in greater detail showing a base 15 and the cover 12. The cover 12 is attached to the base 15 by a pair of screws (not shown) which are located in the pair of apertures 16, 17 formed in the cover 17.

Whilst the cover 12 is detachable from the base 15 in order to assemble the bolt assembly 1, given the electrical nature of the bolt assembly it is preferable that once assembled the cover 12 remains fastened to the base 15. This reduces the likelihood of damage to the microcontroller 18 or micro switches 19 (see Figure 3) occurring during installation of the bolt assembly 1 into the door panel.

Instead it is preferred that the adjustments required to be made to adjust the functionality of the bolt assembly 1 be made without having to remove the cover 12. In this regard it is important to note the screw 20 on the rear wall 13 the base 15 and a catch aperture 21 extending through the cover 12. The importance of these features will be described in greater detail with reference to later illustrations.

Figure 3 illustrates the bolt assembly 1 with the cover detached from the base . Removal of the cover 12 reveals the bolt pivoting about a shaft 22. In particular the bolt 4 illustrated in Figure 3 pivots in a clockwise direction from the extended position shown to a retracted position that can be seen in Figure 5.

The movement of the bolt 4 moves a swivelling arm 23 about a shaft 24 so as to adjust a micro switch associated with the micro controller. This confirms the position of the bolt. drop bolt.doc Figure 4 illustrates in summary the key operated actuator 25, the powered actuator 26 and the movable member 27. The movable member 27 illustrated is a form of a sliding platform 27 that slides between a first position as illustrated in Figure 4 and a second position as illustrated in Figure 5. The sliding platform 27 is biased toward adopting the second position under the influence of a biasing means which in the embodiment illustrated in Figure 5 is a spring bias 28.

Clearly other forms of biasing means are possible.

The sliding platform 27 supports a powered drive 29 that is operable to adjust the position of the movable member 27 from the second position back to the first position. The powered drive 29 includes a motor 30 that rotates a threaded shaft 31 through a gear box 32. The threaded shaft 31 interacts with a driven member 33 that is movable relative to the shaft upon rotation of the structure.

The driven member 33 includes a threaded bore (not shown) for interacting with the threaded shaft 31. The movement of the movable member 27 also interacts with the bolt 4 so that initial rotation of the threaded shaft 31 relative to the driven member 33 as illustrated in Figure 5, will draw the shaft 31 through the driven member 33 to return the movable member 27 to the first position as illustrated in Figure 6. Once the movable member 27 is in the first position further rotation of the shaft 31 will cause the driven member 33 to move along the threaded shaft 31 resulting in pivoting of the bolt 4 from the retracted position to the extended position as illustrated in Figure 4.

The powered actuator 26 controls the movement of the movable member 27 from the first position to the second position. The powered actuator 26 may take any form. However in the embodiment illustrated the powered actuator 26 includes a solenoid 34 that acts on a detent 35 to release a catch 36 associated with the movable member 27. It can be appreciated from Figure 4 that while the detent 35 is in a retained condition, an arrowhead 37 formation of the detent 35 locates behind the catch 36. Upon activation of the solenoid 34, a plunger 38 (see Figure 7) of the solenoid 34 is raised to adjust the position of the detent 35 to a release condition so that the arrowhead 37 of the detent 35 is no longer located behind the catch 36 (see Figure 5). Once in that position the spring bias drop bolt.doc 28 urges the movable member 27 to move from the first position to the second position thereby retracting the latch bolt 4.

It will be appreciated that the bolt 4 may be left in an inappropriate position in the event of a power failure. Accordingly the powered actuator 26 is operable in a fail safe mode or a fail secure mode whereby in the event of a power failure the bolt 4 adopts a retracted position or extended position respectively. The powered actuator maybe configured in any manner to achieve this adjustability and the embodiment illustrated in Figures 7 to 10 is merely one way in which this can be achieved.

Referring to Figure 7 which illustrates the powered actuator 26 in a fail secure mode whereby the solenoid 34 is without power being supplied thereto so that the plunger 38 remains retracted. The detent 35 is biased by a torsion spring 39 to rotate in an anticlockwise direction so that the arrowhead 37 of the detent locates behind the catch 36. In comparison Figure 8 illustrates power being supplied to the solenoid 34 to raise the plunger 38 and rotate the detent 35 against the biasing force of the torsion spring 39. This moves the detent 35 to a release condition so that the arrowhead 37 is no longer located behind the catch 36 and the movable member 27 is free to move from the first position to the second position under the force of the spring bias 28 (see Figure 5). This results in retraction of the bolt 4 from the extended position shown in Figure 7 to the retracted position shown in Figure 8. It ought to be appreciated from the embodiment illustrated in Figures 7 and 8 that whilst power is not supplied to the solenoid 34, such as in the event of a power failure, the bolt 4 will remain in an extended position securing the premises.

The powered actuator 26 illustrated in Figures 9 and 10 is operating in a fail safe mode. Figure 9 includes a solenoid frame 40, which is removed from Figures 7, 8 and 10. The frame 40 captures the solenoid 34 and its position is adjustable relative to the housing 3. This adjustment is achieved by rotating the captured screw 20 to adjust the position of the solenoid frame 40 relative to the housing 3. Furthermore the catch 36 has been rotated through 180 from Figure 8 so as to interact with an opposing side the arrowhead 37 of the detent 35. drop bolt.doc Both these adjustments can be made without removing the cover 12 from the base 15. The screw 20 is accessible from the rear wall 13 of the base 15, and the catch 36 is accessible through the catch aperture 21 as previously described with reference Figure 2. With the solenoid 34 in the position illustrated in Figures 9 and 10, and power supplied to the solenoid 34, the plunger 38 (obscured in Figure 9) will extend to rotate the detent 36 against the force of the torsion spring 39. Figure 9 illustrates the detent 36 in the retained condition whereby the arrowhead 37 locates behind the catch 36. In comparison Figure 10 illustrates the detent 35 in the release condition as a result of the plunger 38 retracting allowing rotation of the detent 35 under the force of the torsion spring 39. The arrowhead 37 of the detent 35 releases the catch 36 allowing the movable member 27 to move from the first position back to the second position. It will be appreciated from the embodiment illustrated in Figures 9 and 10 that a power failure event will result in retraction of the bolt 4 from the extended position to the retracted position.

The key operated actuator 25 is operable to adjust the position of the bolt 4 from the extended position to a retracted position. The key operated actuator 25 may operate in any suitable manner to achieve this result and the embodiment hereinafter described with reference to Figures 11 to 14, is merely one way in which this can be achieved.

Figure 11 illustrates the powered actuator 26 in a fail secure position with the solenoid plunger retracted as would occur during a power failure event. The key operated actuator 25 includes the cylinder lock 10 having a cam 41 which is rotatable on insertion of a key (not shown) into the barrel 11. Figure 11 illustrates the cam 41 of the cylinder lock 10 in a standby position, whereas Figure 12 illustrates the cam 41 having been rotated from the standby position to engage a follower 42. The follower 42 interacts with the detent 35 so as to adjust its position from the retained condition illustrated in Figure 11 to a release condition as illustrated in Figure 12. The preferred follower illustrated includes a plunger 43 which acts against a compression spring 44. A leading end of the plunger 43 has a wedge shape formation for locating under a complementing wedge formation associated with an end of the detent 35. These drop bolt.doc complementing wedge shaped formations result in rotation of the detent 35 against the torsion spring 39 to release the arrowhead from the catch 36, and allowing the movable member 27 to move to the second position. Accordingly this allows a user to adjust the position of the bolt 4 in the event of a power failure to the bolt assembly, provided the user has the key for the cylinder lock.

Referring now to Figure 13 which illustrates the powered actuator 26 in a fail safe position with power supplied to the solenoid 34 so as to extend the plunger 38. It should be noted that the cam 41 of the cylinder lock when in the standby position interacts with a micro switch 19. Provided power is supplied to the bolt assembly 1, and in particular the micro switch 19, movement of the cam 41 from the standby position will adjust the condition of that switch 19. The micro switch 19 interacts with the micro control 18 (see Figure 3) to send a signal to the solenoid 34 to de-activate and retract the plunger 38. This results in retraction of the latch bolt 4 from the extended position illustrated in Figure 13 to the retracted position illustrated in Figure 14.

If the plunger 38 of the solenoid 34 remains in an extended position due to a faulty micro switch 19, faulty microcontroller 18 or faulty solenoid 34, the cam 41 of the cylinder lock 10 can still be rotated to act on the follower 42.

Movement of the plunger 43 to engage and allow rotation of the detent 35 from the retained condition will result in disengagement of the arrowhead 37 from the catch 36. This in turn results in movement of the movable member 27 from the first position to the second position and retraction of the latch bolt 4.

It will be appreciated from the foregoing that a key operated actuator 25 may adjust the position of the bolt 4 from the extended position to the retracted position in other ways. For example the key operated actuator may interact with the microcontroller 18 to cause the motor 30 to operate in a reverse direction retracting the driven member 33 along the shaft 31. Alternatively it may interact directly on the catch 36 without involving interaction of the detent 35. drop bolt.doc The electromechanical bolt assembly as hereinbefore described provides a relatively simple solution for providing the authorised user with greater options for adjusting the safety/security requirements.

Various alterations and/or additions may be introduced into the bolt assembly as hereinbefore described without departing from the spirit or ambit of the invention. drop bolt.doc

Claims (25)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A electromechanical bolt assembly for securing a door panel in a closed position relative to a door frame, the bolt assembly including a housing, a 5 bolt movable relative to the housing between an extended position and a retracted position, a movable member that is movable within the housing between a first position and a second position, the movable member being associated with the bolt so that the bolt adopts a retracted position when the movable member is in the second position, a powered drive 10 that is operable to adjust the position of the movable member from the second position to the first position and operable to move the bolt from the retracted position to the extended position, a powered actuator for controlling movement of the movable member from the first position to the second position, the powered actuator being operable in a fail safe 15 mode or a fail secure mode whereby in the event of a power failure to the bolt assembly with the powered actuator in the fail safe mode the bolt adopts the retracted position and in the fail secure mode the bolt adopts the extended position, a key operated actuator being operable to adjust the position of the bolt from the extended position to the retracted 20 position.

2. An electromechanical bolt assembly according to claim 1 wherein the key operated actuator is operable to adjust the position of the movable member from the first position to the second position to adjust the 25 position of the bolt from the extended position to the retracted position.

3. An electromechanical bolt assembly according to any one of the preceding claims wherein the powered drive is associated with the movable member so as to move therewith in the housing between a first 30 position and a second position.

4. An electromechanical bolt assembly according to claim 3 wherein the movable member slides within the housing, and further including a biasing means for biasing the movable member so as to urge the 35 movable member to adopt the second position. drop bolt.doc

5. An electromechanical bolt assembly according to any one of the preceding claims wherein the mode of the powered actuator is adjustable from outside the housing.

6. An electromechanical bolt assembly according to any one of the preceding claims wherein the powered actuator includes a solenoid having a plunger that is movable relative to a body of the plunger against a bias on energisation of the actuator, a position of the solenoid within 10 the housing being adjustable for adjusting the mode of the powered actuator, the position of the solenoid being adjustable by adjustment of a captured screw.

7. An electromechanical bolt assembly according to claim 6 including a 15 detent that is adjustable between a release condition and a retain condition by operation of the powered actuator, the detent interacts with the movable member whereby in the event of power failure and the powered actuator is in the fail secure mode the movable member is retained in the first position, and when the powered actuator is in a fail 20 safe mode the movable member is released to adopt the second position.

8. An electromechanical bolt assembly according to claim 7 including a adjustable catch associated with the moveable member which is 25 adjustable from outside of the housing when adjusting the mode of the powered actuator.

9. An electromechanical bolt assembly according to any one of claims 6 to 8 wherein the key operated actuator is operable to adjust the condition of 30 the detent.

10. An electromechanical bolt assembly according to claim 9 wherein the key operated actuator includes a cylinder lock having a cam that is rotatable from a standby position by use of an authorised key. drop bolt.doc

11. An electromechanical bolt assembly according to claim 10 wherein the key operated actuator includes a follower that interacts with the cam and detent for adjusting the position of the detent. 5

12. An electromechanical bolt assembly according to claim 11 wherein the follower is biased away from interacting with the detent.

13. An electromechanical bolt assembly according to claim 12 wherein the follower includes a plunger and a compression spring urging the plunger 10 away from interacting with the detent.

14. An electromechanical bolt assembly according to claim 13 the plunger includes a wedge that interacts with the detent to move the detent in a direction substantially perpendicular to a direction of movement of the 15 plunger.

15. An electromechanical bolt assembly according to any one of claims 10 to 14 wherein the key operated actuator is operable to adjust a switch that is adjustable between an open condition and a closed condition, so that 20 when the switch adopts an open condition the bolt is moved from the extended position to the retracted position.

16. An electromechanical bolt assembly according to claim 15 wherein the switch is retained in the closed condition by the cam when the cam is in 25 the standby position.

17. An electromechanical bolt assembly according to claim15 or 16 wherein the switch is biased to adopt an open condition so that when the cam is rotated from the standby position it causes the switch to adjust from the 30 closed condition to the open condition.

18. An electromechanical lock assembly according to any one of claims 15 to 17 wherein the switch is operably connected to the powered actuator so that adjusting the switch from closed condition to the open condition 35 causes the powered actuator to respond as if there was the event of the power failure. drop bolt.doc

19. An electromechanical bolt assembly according to any one of the preceding claims wherein the bolt is pivotable about a shaft between the retracted position and the extended position.

20. An electromechanical bolt assembly according to any one of the preceding claims wherein the powered drive includes a drive shaft that is rotated to adjust the position of the movable member between the second position and the first position.

21. An electromechanical bolt assembly according to claim 20 wherein the drive shaft is rotatable to move the bolt from the retracted position to the extended position once the movable member is in the first position. 15

22. An electromechanical bolt assembly according to claim 21 including a driven member that is movable along the length of the drive shaft when the drive shaft is rotated.

23. An electromechanical bolt assembly according to claim 22 wherein the 20 bolt interacts with the driven member.

24. An electromechanical bolt assembly according to any one of claims 20 to 23 wherein the drive includes an electric motor that is operable to rotate the drive shaft.

25. An electromechanical bolt assembly according to any one of the preceding claim wherein the housing includes a base and a cover, the mode of the powered actuator being adjustable while the cover is attached to the base. drop bolt.doc