EP0106725A1 - Lock with an electric control, and control circuit for a motor-vehicle door lock - Google Patents

Abstract

1. A lock with electric actuation including firstly, a lock comprising a rotary lock bolt (10) and a catch (24), the lock bolt forming a seating (18) for a locking pin (20), the bolt being re-strained elastically towards an opening position wherein the locking pin can penetrate into the seating of the bolt or emerge therefrom, and being retained in the locking position by the catch, the latter being elastically re-strained towards its position wherein it retains the bolt in the locking position, and secondly, an electric control system comprising an electric motor (50) driving a speed reduction gear (48) which is coupled via a clutch (46) to a pinion (44) meshing with a rack (34) for the actuation of the catch, the control system displacing the rack between a first stop position wherein the catch is in a position retaining the bolt in the locking position, and a second position wherein the catch releases the bolt, characterised in that, on the one hand, the lock comprises a means for restraining the rack (34) from its second into its first position, so that when the electric motor (50) is not supplied with power and when the clutch (46) is disengaged, the re-straining means restores the rack into its first position and that on the other hand, the bolt (10) comprises a cam finger (16) which, when the bolt approaches its opening position, moves the catch beyond the position into which it was placed by the rack, so that the catch should no longer be in contact with the latter.

Description

The present invention relates to locks, in particular intended for the doors of automobiles, as well as a door control circuit adapted to this particular type of lock.

Locks used for automobile doors are already known and comprising a rotary bolt and a ratchet, the bolt forming a housing for a keeper, the bolt being resiliently returned to an open position in which the keeper can enter the housing or can get out of it; the bolt is retained in the locking position by the pawl, the latter being resiliently returned to its position in which it retains the bolt in the locking position. When this lock is in the open position and the door on which it is closed is closed, the strike enters the housing of the bolt and pushes it towards its locking position, the pawl coming to retain the bolt in this Last Position.

The invention relates to an electrically operated lock of this type. More precisely, whatever the moment of the failure or of the power failure, the lock according to the invention can be put in the locked position. Furthermore, this advantageous characteristic is obtained using a small number of mechanical elements which are simple, robust and reliable.

More specifically, the invention relates to a lock of the aforementioned type, that is to say comprising a rotary bolt and a pawl, the bolt forming a strike housing and being resiliently returned to an open position in which the strike can freely enter or exit the bolt, the pawl retaining the bolt in the locked position and being itself returned to the position in which it locks the bolt. The lock further comprises an electric control which comprises an electric motor driving a speed reducer coupled by a clutch with an output pinion which meshes with a ratchet operating rack. According to the invention, the lock further comprises a means for returning the rack from a second position, in which it separates the pawl from the bolt and thus allows the door to be opened, to a first position, in which the pawl retains the bolt in the locked position. Thus, when the electric motor no longer receives a current, the clutch is disengaged and the return means returns the rack to its first position. Furthermore, according to the invention, the bolt comprises a cam finger which, when the bolt approaches its open position, spreads the pawl beyond the position in which the rack has placed it, so that the pawl is no longer in contact with it; this feature eliminates all constraints on the rack and ensures proper disengagement of the latter relative to the speed reducer.

For example, the pawl has an operating finger, controlled by the rack, and a hook turned towards the bolt and intended to retain it, and the bolt has a nose intended to be retained by the hook of the pawl, and a finger cam, the nose and the cam finger being placed on either side of the bolt housing, the transverse dimension of the finger being greater than that of the nose so that, when the bolt takes its open position, the finger cam pushes the pawl beyond the position in which the pawl hook releases the bolt nose.

In an advantageous embodiment, the return means comprises a spring.

The invention also relates to a control circuit for an electrically operated lock., In particular a lock of the aforementioned type, that is to say a lock having an operating member moved in one direction by a control electric and automatically called back the other way. According to the invention, this control circuit includes a time relay intended to close, for a determined time, an electrical circuit which comprises, in series, an electrical supply line with a first polarity, a movable contact of the relay, a push-button control member, the electric motor of the lock, and a power supply line with a second polarity. The circuit further comprises a current draw detector mounted in the circuit in parallel at the terminals of the timer relay contact and which, when a current flows through it, is intended to cause control of the timer relay, so that this last-, denying closes its contact and thus causes the circulation of a current controlling the electric motor of the lock.

The push button control member advantageously comprises two push buttons mounted in parallel, allowing, for example, one for internal control and the other for external door control.

When the circuit is intended to control several locks, it comprises a single time relay and a single current draw detector, and it comprises several circuits connected in parallel and each comprising a push-button control member and an electric motor for lock.

It is also advantageous for the circuit to include a locking switch. When the circuit controls several locks, it is desirable that this locking switch is placed in the part of the circuit which is common, for example near the time relay.

To better understand the object of the invention, we will now describe, purely by way of illustration and not limitation, an embodiment shown in the accompanying drawing.

• - les figures 1 à 3 sont des schémas représentant les principaux éléments d'une serrure à commande électrique selon l'invention et illustrant son principe de fonctionnement ;
• - la figure 4 est une coupe verticale à décrochements d'une serrure-selon l'invention, selon IV-IV de la figure 5 ;
• - la figure 5 est une coupe verticale à décrochements selon V-V de la figure 4 ;
• - la figure 6 est une coupe partielle suivant VI-VI de la figure 4 ;
• - la figure 7 représente le schéma électrique d'un circuit de commande de la serrure des figures 4 à 6 ;
• - la figure 8 est un diagramme des temps illustrant le fonctionnement du circuit de la figure 7.

On this drawing :

• - Figures 1 to 3 are diagrams showing the main elements of an electrically controlled lock according to the invention and illustrating its operating principle;
• - Figure 4 is a vertical section with recesses of a lock-according to the invention, according to IV-IV of Figure 5;
• - Figure 5 is a vertical section with notches along VV of Figure 4;
• - Figure 6 is a partial section along VI-VI of Figure 4;
• - Figure 7 shows the electrical diagram of a control circuit of the lock of Figures 4 to 6;
• FIG. 8 is a time diagram illustrating the operation of the circuit of FIG. 7.

Figures 1 to 3 show, in three different positions during operation, the main members of an electrically operated lock according to the invention.

The lock comprises a bolt 10 which can pivot around an axis 12 fixed relative to the body of the lock. The bolt comprises a nose 14 and a cam finger 16 which delimits between them a housing 18 intended to contain a keeper 20. A spring, not shown in FIGS. 1 to 3, recalls the bolt 10 in the direction of arrow 22.

A pawl 24 can pivot around an axis 26 which is also fixed relative to the body of the lock. The pawl has a hook 28 and an operating member or lever 30. The pawl 24 is returned by a spring (not shown) in the direction of arrow 32.

An operating member is constituted by a rack 34. More specifically, this rack which is intended to move in the direction of the arrow 36, comprises a part 38 allowing manual control of the lock and a stop 40 intended to operate the lever 30 of the pawl 24. The rack 34 has teeth 42 which mesh with a pinion 44; it is mounted on a clutch 46, itself coupled to the electric motor 50 by a reduction gear 48 comprising several gears.

The clutch, which is advantageously of the type described in detail in French patent application 80-13642 essentially comprises an external hollow cylindrical member forming a clutch drum 52, and pads 54 intended to come into contact with the internal surface of the drum 52. These pads 54 are normally spaced from this internal surface by a spring 56, but they can be pushed against this surface despite the opposing force of the spring 56 by a pallet 58 mounted on the shaft 60 of the output of the reducer 48. note that when the engine is running it provo as the rotation of the pallet 58, which comes to apply the pads 54 against the drum 52.

We now consider the main stages of operation of the lock shown in Figures 1 to 3. The position of Figure 1 corresponds to the closing of the door. Indeed, the keeper 20 is retained in the housing 18 of the bolt 10 which, despite the action of its spring, cannot pivot because the hook 28 of the pawl keeps it in its locked position.

When the electric motor 50 is supplied, it causes the pinion 44 to rotate in the direction which causes the lifting of the operating member (in FIGS. 1 to 3). Consequently, the stop 40 of the member 34 lifts the operating lever 30 so that the hook 28 moves away from the nose 14 as shown in FIG. 2. The return spring of the bolt 10 then allows the opening of the lock. However, towards the end of its opening stroke, the bolt 10 places its cam finger 16 opposite the hook 28 of the pawl. The transverse dimension of the cam finger 16 is such that the cam finger 16 lifts the pawl 24 as indicated in FIG. 3; the lever 30 departs from the stop 40 of the operating member 34. The door remains open in this position until the electric motor 50 no longer receives current. At this time, the clutch 46 disengages and the operating member 34 can fall back into the position indicated in FIG. 1. However, the pawl 24 remains in the position indicated in FIG. 3.

When the door is pushed to be closed, the keeper 20 enters the housing 18 and causes the latch to tilt to the position shown in FIG. 1. The pawl 24, since it is resiliently returned to its position in FIG. 1 , retains the nose 14 of the bolt by its hook 28, that is to say in the locked position.

The foregoing description shows that the electric control operates only for a very short time, that is to say for the time necessary for the opening operation of the lock. The motor 50 is not powered for the rest of the time. In the event of a power failure or failure, at a time other than the opening command, this interruption has no effect on the operation of the lock. If this cut takes place during the very short instant of the command, the operator can himself maneuver the member 34 by its part 38 which protrudes. This protrudes preferably inside when it is a lock mounted in a vehicle so that the door can always be opened from the inside, for safety reasons, but cannot be opened from the outside.

It is therefore noted that the lock described does not have the drawback of preventing the doors from closing in the event of a power failure. It should only be powered for a very short time.

Figures 4 and 5 show a practical embodiment of an electrically operated lock according to the invention.

In these figures, the references identical to those of Figures 1 to 3 denote corresponding elements. It is therefore not necessary to describe these figures in detail, and it suffices to note the additional members which have not been shown in FIGS. 1 to 3. Thus, FIG. 4 shows the return spring 62 of the bolt and the pawl return spring 64. In addition, it indicates the presence of connectors 66 for powering the motor 50. A bellows 68 provides protection for the operating member 34.

The invention also relates to a control circuit particularly suitable for locks of the type described above.

The circuit shown in Figure 7 allows the electric control of several locks 70 according to the invention. Each lock 70 can normally be controlled by a first push button 72, for example placed inside the door, and a second push button 74 placed for example outside the door. The set of members 70, 72 and 74 is mounted directly on a door 76. Thus, FIG. 7 represents the circuit necessary for the control of two doors. Of course, any number of these circuits can be connected in parallel as suggested in FIG. 7.

The circuit essentially comprises, from an electrical supply line 78 of a first polarity, for example positive, a movable contact 80 of a time relay 82. This contact is mounted in series with a switch. 84 of general condemnation which, when open, prevents operation throughout the circuit. This switch is normally controlled by a barrel controlled by a key. A plurality of switches 84 can be provided, the assembly then being associated with an electronic processing case in order to be able to lock or unlock the vehicle from several points, for example on both sides of the vehicle, from the inside and / or from the exterior, and by various means such as key, frieze zipper, central locking button, infrared remote control or the like. After the switch 84, the circuit comprises the two push-buttons 72, 74 mounted in parallel, the electric motor of the lock 70 and the electric supply line 86 of the other polarity, negative for example. This circuit is normally open. Even if the switch 84 is closed, and even if one of the push-buttons 72, 74 is pressed, as long as the contact 80 of the relay is not closed, the lock 70 cannot be actuated.

According to the invention, a call detection member 88 is mounted in parallel with respect to the contact 80 of the relay. This detector member 88, which has a high impedance, is keen to detect the closing of the circuit which includes, from line 78, the detector 88, the switch 84, the push-buttons 72 and 74 mounted in parallel, the lock 70 and the line 86. When the switch 84 has been closed, the depressing of one or other of the push buttons 72, 74 causes the closure of this circuit. A current of low intensity then flows through the detector member 88. This triggers the time relay 82 which closes its contact 80. Consequently, the lock 70 is then mounted directly between the two supply lines 78 and 86, since the contact 80, the switch 84 and one of the push buttons 72, 74 are all closed. The motor of the lock 70 then causes the lifting of the pawl which allows the opening of the door.

Figure 8 is a diagram illustrating this operation. The abscissa represents time T; the ordinate simply represents, in arbitrary form, the two possible stages, opening and closing, of a push button 72, 74 (upper curve) and of the contact 80 (lower curve). It is noted that, when, at time A, one of the push buttons 72, 74 is pressed, the time relay closes the contact 80 for a time T which is sufficient for the motor 50 of the lock to be able to move the rack 34 and cause the lock to open. At the end of the delay period, contact 80 opens, even if the push-button continues to be held down for a certain time. Those skilled in the art are well aware of various types of timed relay closing a contact for a first period and then remaining insensitive for a second period.

The foregoing description shows that the invention relates to an electrically controlled lock having a small number of elements and whose members are simple and robust.

In addition, the lock control circuit is very simple since it only has, for each door, the lock and two push buttons. The circuit common to all the doors has only a time relay and a call detection device. The operation of the circuit can therefore be very reliable, without its price being high.

It is understood that the lock and the control circuit described may give rise to any modifications, without departing from the scope of the invention.

Claims (7)

1. An electrically operated lock, comprising in the first place, a lock comprising a rotary bolt (10) and a ratchet (24), the bolt forming a housing (18) for a strike (20), the bolt being resiliently biased towards a open position in which the keeper can enter or exit the bolt housing, and being retained in the locking position by the pawl, the latter being elastically returned to its position in which it retains the bolt in the locking position, and secondly, an electric control comprising an electric motor (50) driving a speed reducer (48) which is coupled by a clutch (46) to a pinion (44) which engages a rack (34) for operating the pawl, the control moving the rack between a first stop position, in which the pawl is in the bolt retaining position in the locking position, and a second position, in which the pawl releases the bolt, characterized in that, from a go, the lock comprises a means for returning the rack (34) from its second to its first position, so that, when the electric motor (50) is not supplied and the clutch (46) is disengaged, the return means returns the rack to its first position, and that, on the other hand, the bolt (10) comprises a cam finger (16) which, when the bolt approaches its open position, moves the pawl apart beyond the position in which the rack has placed it so that the pawl is no longer in contact with it. 2. Lock according to claim 1, characterized in that the pawl (24) comprises an operating lever (30) and a hook (28) facing the bolt, the bolt (10) comprising a nose (14) and a cam finger (16) arranged on either side of its opening (18), the transverse dimension of the cam finger being greater than the transverse dimension of the nose. 3. Lock according to one of claims 1 and 2, characterized in that the return means is a spring. 4. Control circuit for an electrically controlled lock according to one of claims 1 to 3, characterized in that it comprises: - a time relay (82) intended to close, for a determined time, an electrical circuit which comprises, in series, an electrical supply line (78) at a first polarity, a movable contact (80) of the relay (82) , a push button control member (72, 74), an electric motor (50) of the lock (70), and a power supply line (86) at a second polarity, and - a current draw detector (88) mounted in the circuit in parallel across the terminals of the. contact (80) of the relay (82), said detector causing, when a current flows there, the control of the time relay (82) so that the relay closes its contact (80) and thus ensures the circulation of a current of control in the electric motor (50) of the lock (70). 5. Circuit according to claim 4, characterized in that the control member comprises two push-buttons, an internal control push-button (72) and an external control push-button (74). 6.Circuit according to one of claims 4 or 5, characterized in that it comprises several circuits (76) mounted in parallel and each comprising a control member (34) and an electric motor (50) lock. 7. Circuit according to one of claims 4 to 6, characterized in that it comprises in series in the circuit at least one general locking switch (84).

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