FR2653480A1 - Electric lock with automatic spring opening - Google Patents

Abstract

Electrical locking device making it possible remotely to lock and unlock doors constituting emergency exits, characterised in that it opens automatically, under the effect of a return spring (R), when its electrical supply is cut. The bolt (P) is driven, on closure, by an endless screw (V), itself rotated by a D.C. electric motor (M), the nut (E) moved by the endless screw is not solidly attached to the bolt. The bolt (P) is held in the closed position by an annular electromagnet (A) which it passes through, whilst the travel switch (I1) which it actuates by arriving in the extreme closure position causes the nut moved by the endless screw to return into the rear position, thus allowing the automatic opening operation of the lock under the effect of the return spring when the supply of the electromagnet is cut.

Description

Collective premises welcoming the public have emergency exits intended to ensure their rapid evacuation
if necessary.

For this, they are provided with bars called "anti-panic" allowing an unlocking inside by a simple push but prohibiting unlocking from the outside.

The disadvantage of such a system is that it makes these exits permanently accessible, even if there is no danger and that, consequently, unwise people can go out, for example, by carrying goods not paid.

The purpose of this electric lock is to allow remote locking and unlocking maneuvers of emergency exits while ensuring general unlocking, in the event of danger, without energy supply.

For this, the principle is to mount the bolt of the lock so that in the absence of electric current its stable position is the opening.

In other words, if the current fails, the lock will open naturally under the effect of a return spring.

To cause its closing, om ensures its displacement forwards by means of a direct current electric motor driving a worm which penetrates freely inside the bolt.

So that the nut which is driven by the worm is not secured to the bolt. It will only move in the direction of closing.

So when the bolt is tensioned, the nut simply pushes the latch forward by bandaging the return spring.

When the bolt reaches the front end of the stroke, it is supported by an annular electromagnet which keeps it in the closed position as long as it is supplied with electricity.

At the same time a limit switch, actuated by 1 advance of the bolt, causes the return driven to its initial position of the nut driven by the worm and the electric motor
When it has reached its initial position, the nut in question actuates a limit switch which ensures the engine stops.

The fact of cutting the current by any external means, de-energizes the electromagnet which releases the bolt.

The latter then returns to its open position under the effect of the spring.

Figure 1 shows a plan view of the lock. in the "closed" position, cover removed. FIG. 2 represents a sectional elevation view of the same lock, in the "open" position.

The lock consists of a folded sheet frame with 3 support faces.

A direct current electric motor M is fixed by a flange to the rear support face and its axis passes through this support face.

The V steel worm is integral with the motor axis and is rotated by it
The worm screw V drives in translation the bronze nut E whose rotation is prohibited by any ad hoc means, for example by a headless screw moving linearly in an appropriate groove made in the printed circuit placed at the bottom of the chassis.

The nut E includes a stop intended to actuate the limit switch I2 on its return to the rear position.

The front bearing face has a hole serving as the first bearing for the mobile assembly constituted by the bolt P.

The bolt P has a cylindrical part of large diameter intended to withstand burglary forces and, at its rear part, a tube T made of non-magnetic material, of smaller diameter intended to guide it through the diameter hole corresponding which serves as a bearing in the intermediate support face.

At the front part of the bolt located beyond the front bearing face, over a length equal to its stroke, there is a taper of 3% intended to facilitate the opening of the latch if pressure is exerted on the door.

The worm screw V will rotate freely inside the tube T.

The spring R, threaded around the front part of the bolt P, will rest on the one hand on the front bearing face and on the other hand on a shoulder placed at the rear of the part of large diameter of the bolt P .

At rest, the spring R will cause the bolt to return, then keep it in the open position.

In addition, an annular electromagnet A, placed on the intermediate support face and fixed to the latter on the side of the worm, is crossed by the tube T of the rear part of the bolt P.

At the end of the tube T, there is a disc D, integral with the tube, intended to ensure the magnetic continuity of the electroaiamnt A when the bolt is in the open position thereby ensuring its maintenance in this position as long as the power supply of the electromagnet is ensured.

The rotation of the disk D is prohibited by any ad hoc means, for example by a headless screw moving in an appropriate groove made in the printed circuit placed at the bottom of the frame of the lock.

Finally, on disk D, there is a stop intended to actuate, in the direction of opening, the limit switch.
He .

The 2 limit switches I1 and I2, all the electronic components intended to ensure the functioning of the system as well as the connection terminals, are placed on the same printed circuit located in the bottom of the frame of the lock between the support face rear and the intermediate support face.

FIG. 3 represents the electrical diagram of the device.

Without power supply, the lock is open, and the nut
E is in rear position.

The limit switch It is closed and the limit switch I2 is open.

Relay Re is at rest.

Switching on the current supplies the coil of the relay Re through the limit switch I1.

The coil of the electromagnet A is also supplied.

The relay Re goes up and, via its 2 change-over contacts, supplies the motor in the direction of closing the latch through the diode Di which, for the corresponding direction of current, short-circuits the end switch stroke I2 then open.

The nut E moves linearly along the worm screw V and, by pressing on the disc D causes the bolt P to advance in the closing direction while thus tightening the spring
R.

The disc D advances until it comes into contact with the armature of the electro-aiamnt A which keeps it in this position.

At the same time, the stop of the disc D actuates the limit switch Ii which cuts the supply of the coil of the relay Re.

It drops and thus reverses the polarities at the terminals of the motor M.

The latter therefore starts in the opposite direction until the stop of the nut E actuates the limit switch 12 which cuts the power supply to the motor M because the diode Di is polarized in the opposite direction of the current .

The motor M then stops, thus causing the nut E to stop.

To cause the lock to open, simply cut off its power.

The electromagnet A being de-energized, will release the bolt which, released, will immediately return to the open position under the action of the spring R.

The push button with opening Bp, placed on the cover of the lock, allows its local opening.

A terminal of the push button Bp is out to allow the remote control to be put into service or out of service.

A magnetic contact C, fixed to the cover of the lock and whose magnet is fixed to the strike, prevents closing of the lock if the door is open and causes its automatic reclosing when the door is closed if the lock is powered.

An electronic timer produced with the NPN TR type transistor, the resistors R1, R2, R3 and the capacitor
Co, causes the relay Re to fall if, after a few seconds, the lock has not fully closed.

The engine M then starts in the opposite direction and the bolt P and nut E assembly returns to its initial opening position.

To carry out another attempt at closing, it will first be necessary to cut off the supply of the lock for the time necessary for the capacitor Co to discharge, then re-energize the lock.

Finally, a terminal of the limit switch It is output to supply the indicator light Vr which will remain on until the lock is completely closed

Claims (9)

 CLAIMS 1) Device for electrically locking doors constituting emergency exits comprising a bolt P sliding in a metal frame, driven, at closing, by an endless screw V, itself rotated by an electric DC motor M, integral with the frame and, at the opening, by a return spring R, bandaged by the movement of the bolt P during the closing operation, characterized in that the worm screw V penetrates freely inside the P bolt hollowed out for this, the nut E, driven in translation by the worm screw V merely pushing the bolt P in the closing direction.  2) Device according to claim 1 characterized in that  the P bolt is held in its closed position by a  annular electromagnet A which it crosses.  3) Device according to claims 1 and 2 characterized by a limit switch Il which, actuated by the arrival of the bolt P in the closed position, drops the relay Re causing the restarting of the drive motor M of the worm screw V in the direction of the opening of the lock, without allowing the bolt P to move back, blocked that it is in the closed position by the annular electromagnet A which it crosses, in that the nut E actuates the rear limit switch 12 which cuts the power supply to the motor M when said nut E reaches its initial position corresponding to the total opening of the lock, and in that the limit switch 12 is short-circuited by the diode Di which authorizes the passage of electric current only in the direction corresponding to the closing of the lock.  4) Device according to claims t and 3 characterized in  what an electronic timer constituted by the tran  sistor TR, the capacitor Co and the 3 resistors Ri, RZ and  R: causes the automatic cut of the power supply  of the coil of the relay Re if, at the end of the time at which it  corresponds, the bolt P has not yet reached its position  closing end.  5) Device according to claims i and 3 characterized  by the fact that the covers of the lock and of its left include  a magnetic contact C cutting the power supply to the lock  the door is not closed.  6) Device according to claims i and 3 characterized by  the fact that a push button Bp, with closed electrical contact  at rest, locally cuts the power supply to the lock,  causing it to open. 7) Device according to rendication 5 characterized in that the terminals of the push button Bp of local control are accessible to allow the commissioning or deactivation, remotely, of said local control. 8) Device according to claims i and 3 characterized by the fact that the terminals of the limit switch li actuated by the bolt when it reaches its extreme closing position are accessible to allow remote signaling of the state of the lock. 9) Device according to any one of claims 1 to 8 characterized in that all the electrical and electronic elements which contribute to the operation of the set of limit switches, relay diodes, transistor, capacitor, resistance, connection terminals of the lock, of the magnetic contact of the cover, of the local control push button, etc. are grouped together on a single fine printed circuit at the bottom of the bolt frame.