ELECTRIC CENTRAL-LOCKING ACTUATOR FOR A VEHICLE

Abstract: An electric central-locking actuator for a vehicle lock, consisting of a casing (2) containing an electric motor (3), a reversible screw (5) coupled with an output pinion (4) of the motor which can be driven in rotation by the latter, a nut (7) through which the screw passes, locked against rotation and which can drive a carriage in translation by springs (9, 11), and a central-locking return lever (12) coupled with the carriage, characterised in that the carriage is fitted with a rack (14) and pinion brake (16) to reduce the impact of noise incurred by the travel of the carriage.

Description: Electric central-locking actuator for a vehicle The present invention relates to an electric central- locking actuator for a vehicle lock. This actuator consists of a casing containing an electric motor, a reversible screw coupled with an output pinion of the motor which can be driven in rotation by the latter, a nut through which the screw passes, locked in rotation, which can drive a carriage in translation by resilient means, as well as a central-locking return lever coupled with the carriage. These central-locking actuators, which are reversible or can be declutched, are fitted onto the corresponding lock. In general, these actuators use motors with very high rotation speeds. These motors therefore generate rapid internal movements in the actuators, which produce impact noise when the carriage reaches the end of its movement. The objective of this invention is to limit this impact noise. In accordance with the invention, the carriage is fitted with braking means to reduce impact noise incurred by the travel of the carriage. By virtue of one advantageous embodiment, said braking means consist of a rack fixed to the side of the carriage and a pinion-brake, secured to the casing, which co-operates with the rack. Consequently, when the nut compresses the resilient means to drive the carriage, the rack drives the pinion of the brake- pinon in rotation, which opposes a torque resisting the displacement of the carriage. The invention will now be described with reference to the appended drawing illustrating one embodiment, which is given by way of example and is not restrictive in any respect. - Fig. 1 - The single drawing is a perspective view, essentially to scale, of one embodiment of the electric central-locking actuator as proposed by the invention. The electric central-locking actuator illustrated in the drawing is designed for use with a vehicle lock, not illustrated, to provide central locking or unlocking thereof in its latched position. This actuator 1 consists of a casing made of two half- shells in a plastics material, one of which, forming a cover plate 2, is illustrated. This cover plate 2 contains an electric motor 3, the output shaft of which is fitted with a pinion 4, and a reversible screw 5 fitted with a gear 6 coupled with the pinion 4, the rotation of which will in turn rotate the screw 5 about its axis. The actuator also has a nut 7 through which the screw 5 passes, which is prevented from rotating by the side walls of a carriage 8 in which is it disposed and which contains the reversible screw 5. Arranged on each end of the screw 7 are resilient means consisting of helical springs 9, 11 respectively, coaxial with the screw 5. The end of the carriage 8 is pivotally mounted on a return lever 12, provided with a toothed portion 13 which co-operates in a known manner with a central-locking lever, not illustrated. The carriage 8 is provided with a rack 14 secured to the side of the carriage, on the side thereof opposite to the electric motor 3. The toothing of the rack 14 meshes with a pinion 15 of a pinion-brake 16, consisting in a known manner of a viscous coupling device. The pinion-brake 16 is fixed to the cover plate 2 by means of side tabs 10, in an appropriate manner, for example screws. This pinion-brake consists of a pinion 15 rotatably mounted about a shaft 17. The actuator described above operates in the following manner. When a power supply is applied to the actuator, the motor 3 drives its pinion 4 in rotation, which in turn drives the gear 6 and the screw 5 in rotation. The rotation of this latter displaces the nut 7 in translation in the carriage 8. The nut 7 compresses one of the two springs 9 and 11, depending on the direction of rotation of the motor and the screw 5. At the end of compression, the spring 9 or 11 then drives the pinion 15 of the brake-pinion 16 in rotation, which opposes a braking torque resisting translation of the carriage 8. The opposition to the displacement of the carriage 8 reduces its displacement speed in both directions. Due to this reduced displacement speed, the impact noise that would normally be generated by the halt in the movement of the carriage 8 and the carriage return 12 is reduced to a minimum. In one embodiment, the rack 14 and pinion-brake 16 system may be replaced by any other equivalent means that will provide braking for the carriage. GLOSSARY 1 = actuator 2 = cover plate 3 = electric motor 4 = pinion 5 = reversible screw 6 = gear 7 = nut 8 = carriage 9, 11 = helical spring 12 = central-locking return lever 13 = toothed portion 14 = rack 15 = pinion of the pinion-brake 16 = pinion brake 17 = shaft

Claims: CLAIMS 1. An electric central-locking actuator for a vehicle lock, consisting of a casing (2) containing an electric motor (3), a reversible screw (5) coupled with an output pinion (4) of the motor which can be driven in rotation by the latter, a nut (7) through which the screw passes, locked against rotation and which can drive a carriage in translation by resilient means (9, 11), and a central-locking return lever (12) coupled with the carriage, characterised in that the carriage is fitted with braking means (14, 16) to reduce the impact noise incurred by the travel of the carriage. 2. An actuator as claimed in claim 1, characterised in that said braking means consist of a rack (14) fixed to the side of the carriage (8) and a pinion-brake (16) secured to the casing (2), which meshes with the rack. 3. An electric central-locking actuator substantially as described herein and/or as shown in figure 1.

Inventors: OTTOLINI PHILIPPE, OTTOLINI, PHILIPPE
Applicants: MERITOR LIGHT VEHICLE SYS LTD, OTTOLINI PHILIPPE, MERITOR LIGHT VEHICLE SYSTEMS - FRANCE, OTTOLINI, PHILIPPE
Application year: 1998
Main classification: E05B47
IPC codes: E05B17, E05B47, E05B65, H02K7