INCLUDING THIS DEVICE

The present invention relates to an electromechanical safety actuator, which may be used in particular, but not exclusively, in the manufacture of an electrically ^* -operated lock and, in general, in systems for controlling access to an environment,

The electromechanical safety actuator of the invention is characterised in that it includes a support structure; an assembly of moving parts mounted in the said structure and movable along a predetermined direction and including a (first) electrical actuator operable to drive a control member fixed thereto along a working stroke, moving it in a first sense along the said direction from a rest position to a working position, and in the opposite sense to return it to the rest position; there being associated with the said assembly resilient biasing means, and a releasable locking device, provided to assume:

- a normal locking condition in which it holds the said assembly in a normal, predetermined working position in relation to the structure, against the action of the said biasing means, and

- an emergency release condition in which it allows

the said assembly and associated control member to move a distance at least equal to the aforesaid working stroke of the control member along the said direction, in the opposite sense to the said first sense, under the action of the said resilient biasing means.

The invention also relates to an electrically-operated lock and an access control system which include such an electromechanical safety actuator.

Further characteristics and advantages of the invention will become clear from the following detailed description, provided purely by way of non-limitative example, with reference to the appended drawings, in which:

Figures 1 to 3 are sectional views of an electrically- operated lock including an electromechanical safety actuator according to the invention;

Figure 4 is a partially sectioned view of an electrically-operated lock according to the invention; and

Figure 5 is a block diagram of an access-control system which includes an electromechanical safety actuator according to the invention.

In Figures 1 to 4, an electrically-operated lock according to the invention is generally indicated 10. It includes a support casing 1 constituted (for example) by a metal

container shaped like a small rectangular tank.

An electromechanical safety actuator, generally indicated 20, is mounted in the casing 1 to control the position of two translatable control members 2 and 3. At an end 2a of the control member 2 is fixed a member 4 carrying a plurality of parallel bolts 5 which extend through corresponding apertures in an end wall of the casing 1.

The electromechanical actuator 20 comprises an assembly 21 which includes a slide 22 with an electric motor 23 securely fixed thereto. In the embodiment illustrated, this motor includes a rotor 24 threadably engaged by a threaded shaft 25 the ends of which are securely fixed to the control members 2 and 3, at 26 and 27 respectively.

Two transverse abutment stops 28 and 29 are fixed inside the casing 1, on opposite sides in relation to the direction of translation of the assembly formed by the control members 2 and 3 and the -threaded shaft 25. Respective studs 30, 31, parallel to each other and to the axis of the motor 23, are fixed to these abutment stops (see in particular Figure 3) . Two helical springs 32 and 33 are arranged with their respective first ends around the studs 30 and 31 and their other ends bearing against the slide 22.

A toggle mechanism, generally indicated 34, is associated with the end of the slide 22 opposite to the springs 32, 33. This mechanism comprises two rods 35, 36, pivoted at 37. The rod 35 is pivoted at 38 on the support casing 1. At the end towards the motor 23, the rod 36 has a slot 36a through which a pivot pin 39 fixed to the slide 22 extends with clearance.

A wire spring 40 is disposed around the pivotal connection 38 and urges the rod 35 to rotate clockwise, towards the upper wall of the casing 1.

An oscillating member 41 is pivoted at 42 on the support casing 1 and has a toothed portion 43 at one end. At the top, the member 41 has a curved projection 44 from which extends downwardly a section 45 provided to cooperate like a cam with the central pivot pin 37 of the toggle mechanism 34.

The toothed portion 43 meshes with a sprocket wheel 46 which has a small diameter and is fixed for rotation with a gear 47 which meshes with a sprocket fixed to the shaft of a miniature electric motor 49 fixed to the support casing 1.

The motor 49 is provided to drive the oscillating member 41 from the position shown in Figures 1 and 2 to the position shown in Figure 3.

In the position of Figures 1 and 2, the member 41 is positioned so that its cam section 45 allows the central pivot pin 37 of the toggle mechanism 34 to lie above a line between pivotal connections 38 and 39 at the ends of this mechanism. In this condition, the central pivot pin 37 bears against the cam section45 of the member 41 and holds the slide 22 in the position shown, in which the springs 32 and 33 are compressed. The positions of the slide and the motor 23 shown in Figures 1 and 2 correspond to the normal working position. In this condition, energisation of the electric motor 23 causes a translation of the threaded shaft 25 and the control members 2 and 3 connected thereto. In particular, by activating the motor 23 it is possible to move the bolts 5 from a retracted or rest position (Figure 1) to the extended or working position of Figure 2, and vice versa.

A rod 50, fixed to the slide 22, carries two microswitches 51 and 52 which can be operated by the respective heads 53 and 54 of a member 55 fixed to the threaded shaft 25. The microswitches 51 and 52 cooperate with the member 55 to act as travel-limit sensors for cutting power to the motor 24 when the bolts 5 have reached their extended position and their retracted position respectively. The member 55 has an end portion 55a which is slidably engaged in a rectilinear slot of a fixed wall 55b.

The toggle mechanism 34, the oscillating member 41, the electric motor 49 and the associated gears 46 to 48 form

together a releasable locking device, able normally to hold the assembly 21 locked in the working position of Figures 1 and 2.

The function of this releasable locking device will now be explained in greater detail .

Conveniently, the oscillating member 41 has a further, manual control device such as -that generally indicated 60 in Figures 1 and 2. In the embodiment illustrated, this device includes a locking cylinder 61 supported by the cover 1' of -Ore casing 1 (see Figure 4) . Rotation of this cylinder, controlled by a key, not shown, is able to rotate a lever 62 (Figures 1 and 2) carrying a pin 63 which bears against the oscillating member 41, urging it to move from the condition shown in Figures 1 and 2 to the condition shown in Figure 3.

The operation and the purpose of the manual release device 60 will be described in more detail later.

As shown in Figure 4, the control member 2 can cooperate with a deviator 70, known per se, arranged in the casing 1 to control the movement of two locking rods, a lower 71 and an upper 72, along a direction perpendicular to that along which the bolts 5 move, so as to engage/ disengage these rods with or from respective locking elements 73, 74 which are fixed, respectively, to the floor and to the

wall in which the door carrying the lock 10 is mounted.

Outside the casing 1 of the electrically-operated lock, the control member 3 extends into a similar deviator device 80 which, in dependence on the movement of the control member, moves two further locking rods 81, 82 so that they engage with or disengage from respective associated locking elements 83 and 84.

With reference to Figures 1 to 3, two further microswitches 65, 66 are also mounted in the casing 1 for providing respective electrical signals when the oscillating member 41 and the toggle mechanism 34 are in the respective positions shown in Figures 1 and 2.

The electrically-operated lock 10 described above conveniently forms part of a system for controlling access through an aperture closed by a door or the like, with which the electrically-operated lock is associated. The general structure of such an access control system is schematically illustrated in Figure 5.

This system basically includes an electronic control unit 90 with a plurality of inputs, generally indicated 91, connected to the microswitches 51, 52, 56, 65 and 66 of the electrically-operated lock, and to two outputs 92 and 93 for controlling the electric motors 23 and 49.

The electronic unit 90 is normally supplied through a power supply 94, the input of which is connected to the electrical mains.

Conveniently, the electronic unit 90 may be supplied by a buffer accumulator 95 with which is associated, in known manner, a recharging device 96 connected to the mains.

The supply inputs of the electronic unit 90 are also conveniently connected to a socket 97 which may be connected to a commercially available, portable battery 98, for example of the type used in portable radios. Conveniently, the socket 97 is positioned near the door with which the electrically-operated lock 10 is associated, outside the environment to which the door controls access .

The electronic unit 90 is preset to activate/de-activate the electrically-operated lock 10 in dependence on coded control signals transmitted to it by means of a control device 100. This latter may be constituted by a coded electronic key or by a fixed keyboard provided for entering a predetermined command code, or it may be constituted by a remote-control device able to transmit coded command signals to the unit 90, for example by ultrasound or by infra-red radiation or by radio frequency transmission.

In the following description it is assumed that the device 100 is a remote-control device. It is clear, however, that the points which follow apply equally to a device 100 constituted by the other means described above.

The device 100 may conveniently have two control push¬ buttons 101 and 102, the first providing control of normal opening/closing of the electrically-operated lock 10 and the second enabling the lock 10 to be released in the case of an emergency, as described hereafter.

The access-control system which includes the electrically- operated lock 10 operates as follows.

In normal conditions, the assembly of moving parts 21 (slide 22, electric motor 23) of the electrically- operated lock is held in the normal working position of Figures 1 and 2 by the releasable locking device which includes the toggle mechanism 34, the oscillating member 41 and the electric motor 49.

In these conditions, pressing the button 101 of the remote-control device 100 sends a coded signal to the electronic control unit 90. This compares the signal received with a previously memorised identification code and, in the case of positive identification, activates the electric motor 23 so as to move the bolts 5 and the

(possible) locking rods 71, 72 and 81, 82 from their retracted to their extended positions and vice versa.

Should there be a momentary mains power failure, the electronic control unit 90 is supplied by the buffer accumulator 95.

If, after having commanded the release of the lock (that is the retraction of the bolts 5 and the rods 71, 72, 81, 82) by pushing the button 101 of the remote-control device 100, this operation is not carried out, for example because of a failure of the electric motor 23, the user can in any case control the release of the electrically-operated lock 10 by pressing the emergency- release button 102 of the remote-control device. As a result of this action, the remote-control device sends a coded signal to the electronic unit 90 which, on recognising the code, activates the miniature motor 49 of the electrically-operated lock, causing the oscillating member 41 to move from the position of Figures 1 and 2 to the position of Figure 3. As a result of this movement by the member 41, its cam section 45 causes the central pivot pin 37 of the toggle mechanism 34 to move downwardly, below the straight line joining the pivotal connection points 38, 39 at the ends of this mechanism. Consequently, the movable assembly 21 (slide 22, electric motor 23, threaded shaft 25 and control members 2 and 3) is made to translate by the springs 32, 33 into the

position shown in Figure 3. The travel of the assembly is such that it retracts the bolts 5 into the support structure 1 and disengages the (possible) locking rods 71, 72 and 81, 82 from their associated retaining devices.

In one particularly unfortunate situation, it is possible that the button 102 is pressed but the emergency release operation described above does not take place, for example because mains electricity has failed and the buffer accumulator 95 is low, meaning that no power is supplying the electronic control unit. In this case, the user may conveniently fit a portable, commercially available battery, such as that indicated 98 in Figure 5, to the socket 97 thereby enabling this battery to supply the unit 90. At this point, renewed pressure on the button 102 will send the coded emergency release signal to the unit 90 which, once it has positively recognised the code, will activate the miniature motor 49, supplying it with current delivered by the battery 98 fitted to the socket 97.

The access-control system described above may also include devices able to recognise an identification code transmitted via a telephone line. In this case, the system must naturally be connected or connectable to a telephone line.

The control unit of the system will also release the electrically-operated lock in an emergency upon recognising the said code transmitted to it via a telephone line.

The manual control device 61, on the other hand, enables the electrically-operated lock to be released in an emerg¬ ency from inside the environment, which may be accessed through the door. In the case of a failure or malfunction of the system of Figure 5, it is possible to move the oscillating member 41 from the position of Figuresl and 2 to the position of Figure 3 by using a key -in the cylinder lock 61 to rotate the lever 62 anti-clockwise and thereby release the electrically-operated lock as a result of the assembly of moving parts 21 being moved by the springs 32, 33.

In order to prevent lever 62 from being rotated by means of the lock 61 while the electromechanical lock actuator is in the inoperative condition shown in Figure 1, a locking arrangement (not shown) can be conveniently associated with said lever 62; this locking arrangement can include (for instance) a blocking member carried by the control member 3 and capable of preventing the oscillation of said lever 62 when member 3 is in the position of Figure 1.

After an emergency release Operation (and naturally after having resolved the problem which necessitated the emergency operation) , the electrically-operated lock may be put back into service, that is into its normal operating condition, in the following manner.

A signal commanding closure of the electrically-operated lock is transmitted to the electronic unit 90 by pressing the button 101 of the remote-control device 100. On posivi- tely recognising the code, the electronic unit 90 first starts the miniature motor 49 so as to return the oscillating member 41 to the position shown in Figures 1

and 2, in which its cam section 45 does not obstruct the passage of the central pin 37 of the toggle mechanism 34 beyond the straight line connecting the pivotal connection points 38 and 39. When the member 41 has reached the position of Figure 1, the microswitch 65 transmits a corresponding signal informing the electronic unit 90. At this point the said unit activates • the electric motor 23 so that, together with the slide 22, it translates along the threaded shaft 25, towards the left according to Figure 3. As a result of this translation, the toggle mechanism 34 is extended and, as soon as the central pin 37 is aligned with the pivotal points 38 and 39, the wire spring 40 causes the central pin 37 to pass beyond the line joining these pivotal points 38 and 39. In this condition, the central pin 37 bears against the cam section 45 of the oscillating member 41.

The microswitch 66 sends a signal informing the electronic unit 90 that the toggle mechanism 34, as well as the slide 22 and the electric motor 23, have been returned to their normal working position (Figure 1) . Activated by the slide 22, the microswitch 56 sends a signal to the electronic unit 90 which, on reception of this signal, is set to enable the miniature motor 49 to be supplied with inverse current whenever a new emergency release operation is required.

Naturally, the principle of the invention remaining

unchanged, the embodiments and manufacturing details may be varied widely from the above description and illustrations, provided purely by way of non-limitative example, without departing from the scope of the present invention.