Driver for an actuating member particularly for the safety lock of a vehicle door

Abstract

 The driver (19) includes, in series with the motor (11), a two-way solid-state switch (23), the trigger voltage of which is supplied via a resistor (27) connected between the control terminal (26) of the two-way switch (23) and the motor (11). When the safety lock is operated electrically, the supply voltage is supplied to one of the inputs (5, 6) of the driver (19) to trigger and so close the two-way switch (23) and supply the motor (11) normally. In the absence of the electric open/close command, the two-way switch (23) is open, and the motor (11) finds an open circuit at its terminals, so that, when the safety lock knob is operated manually, the motor (11) rotates without generating any counter-electromotive force and, hence, with substantially no resistance.

Description

[0001] The present invention relates to a driver for an actuating member, particularly for the safety lock of a vehicle door.

[0002] Electric drivers for on-vehicle actuating members are known, which comprise electric motors connected to the vehicle battery and for moving the actuating members between two or more predetermined positions.

[0003] Purely by way of a preferred non-limiting application of the present invention, reference will be made in the following description to drivers of the safety locks of the rear doors of a vehicle.

[0004] Safety lock mechanisms normally comprise a safety lock and a manually operated actuating member (knob); and the safety lock may assume a lock or release position corresponding respectively to a first and second predetermined position of the manually operated actuating member.

[0005] On vehicles equipped with electrically operated safety locks, these may be operated both manually, by pressing or releasing the knob, and electrically by means of an electric motor connected to the supply unit. Electric operation is normally centralized to act simultaneously on all the vehicle doors.

[0006] At present, when the safety lock is set to the lock or release position, the electric motor is grounded to prevent undesired operation or no-load consumption of the motor. As a result, manual operation of the knob moves the motor, and generates, within the motor, an induced counter-electromotive force which tends to brake its movement. The manual force applied to move the knob must therefore overcome the resistance generated within the motor, which is not always appreciated by the user.

[0007] It is an object of the present invention to provide a driver designed to overcome the aforementioned drawback, but without impairing the safety of the motor in the absence of manual or electrical control.

[0008] According to the present invention, there is provided a driver for a safety lock of a vehicle door, comprising a first and a second supply input; and a control electric motor for said actuating member, connected between said first and said second supply input; characterized by switching means connected between said motor and said first supply input, and defining an open circuit in the absence of an operating command of said driver, and a closed circuit in the presence of said operating command.

[0009] A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows an electric diagram of a driver assembly for activating the safety locks of the doors of a vehicle;

Figure 2 shows an electric diagram of the driver according to the present invention.

[0010] Numbers 1, 2 and 3 in Figure 1 indicate drivers fittable respectively to the front and rear side doors and the rear door of a vehicle (not shown).

[0011] Drivers 1-3 are connected to one another in parallel and to a supply and control unit 4, and control (in known manner not shown) respective door safety locks (not shown).

[0012] Each of drivers 1-3 has two inputs 5, 6 connected to two (supply voltage and ground) outputs 8, 9 of unit 4, and comprises an electric motor 11 between inputs 5 and 6.

[0013] Each driver 1 also has two outputs 13, 14 connected respectively to two inputs 15, 16 of unit 4, and comprises a microswitch (not shown) having a contact 17 movable between a first and a second position respectively grounding output 13 and output 14, and corresponding to the two, open and closed, positions of the respective safety lock.

[0014] In known manner not shown in detail, unit 4 comprises internal switching means by which outputs 8, 9 are grounded or connected to supply voltage V_cc. More specifically, in the absence of an operating command, outputs 8, 9 are both grounded to short motors 11.

[0015] Power operation of the safety locks of the doors is centralized, and involves feeding an external command enabling supply of motors 11 to supply and control unit 4. More specifically, depending on whether the safety lock is to be closed or opened, unit 4 supplies input 5 with supply voltage and grounds input 6, or vice versa, so that motors 11 operate in one direction or the other.

[0016] The position of microswitch contacts 17 permits unit 4 to know the operating position (open or closed) of the front door safety locks at all times, by detecting the presence of ground on input 15 or input 16.

[0017] Instead of being operated electrically, the safety lock may also be operated manually by pressing or releasing the knob to close or open the lock on each door separately. As stated, however, manual operation involves a certain amount of effort to overcome the counter-electromotive force of the relative motor 11.

[0018] In order to solve this problem, and as shown in Figure 2, drivers 2 of the rear side doors are replaced by drivers 19, each of which, like devices 2, has two inputs 5 and 6 with motor 11 in between. According to the present invention, between one of inputs 5, 6 and motor 11 there is provided a switching element 22 comprising a known two-way solid-state switch 23 (in this case, a TRIAC). In the example shown, triac 23 has a first terminal 24 connected to input 5, a second terminal 25 connected to motor 11, and a control terminal 26 connected to motor 11 via a resistor 27.

[0019] Driver 19 in Figure 2 operates as follows.

[0020] In the absence of a door opening or closing command, inputs 5 and 6 are grounded, so that triac 23 is turned off and motor 11 maintained in an open circuit.

[0021] In the presence of an electric door opening or closing command, unit 4 supplies voltage V_cc to one of inputs 5,6 and grounds the other input 6, 5, so that a voltage sufficient to trigger triac 23 is supplied between terminals 24 and 26 via resistor 27, and triac 23 therefore closes to connect motor 11 between the supply and ground and so turn on the motor.

[0022] Once the door is activated, terminals 5, 6 are again grounded to open triac 23.

[0023] When driver 19 is operated manually, therefore, motor 11 finds an open circuit at its terminals, and rotation of the motor when the knob is operated results in no induced counter-electromotive and hence no braking force.

[0024] The driver according to the invention therefore provides for manually operating the safety lock knob with very little effort, and also affords the further advantage of being integrated in the safety lock itself, thus leaving the vehicle wiring unchanged.

[0025] Clearly, changes may be made to the driver as described and illustrated herein without, however, departing from the scope of the present invention.

Claims

1. A driver (19) for an actuating member, in particular for a safety lock of a vehicle door, comprising a first (5) and a second (6) supply input; and a control electric motor (11) for said actuating member connected between said first (5) and said second (6) supply input; characterized by switching means (22) connected between said motor (11) and said first supply input (5), and defining an open circuit in the absence of an operating command of said driver (19), and a closed circuit in the presence of said operating command.

2. A driver as claimed in Claim 1, characterized in that said switching means (22) comprise a two-way switch (23) having a first terminal (24) connected to said first input (5), a second terminal (25) connected to said motor (11), and a control terminal (26) receiving an activating signal.

3. A driver as claimed in Claim 2, characterized by a resistive element (27) connected between said control terminal (26) and said second terminal (25).

4. A driver as claimed in Claim 2 or 3, characterized in that said two-way switch (23) is a triac.

Drawing