Electricity: magnetically operated switches – magnets – and electr – Electromagnetically actuated switches – Latching means
Reexamination Certificate
2000-11-10
2001-10-09
Luebke, Renee (Department: 2833)
Electricity: magnetically operated switches, magnets, and electr
Electromagnetically actuated switches
Latching means
C335S207000, C200S061540, C200S327000, C200S556000
Reexamination Certificate
active
06300852
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a stalk switch attached to a steering column or the like of an automobile to operate turn signal lamps or wipers, and more particularly, to a latch mechanism for latching a control lever in an operating position.
2. Description of the Related Art
A left stalk switch and a right stalk switch are usually attached to a steering column of an automobile. One stalk switch is called a “turn signal switch” and used for operating turn signal lamps, and the other stalk switch is used for operating wipers or the like. Of these stalk switches, the turn signal switch rotatably supports a control lever on a housing integrally formed with the steering column. By rotating the control lever from a neutral position to either of left and right turn signal positions, a lamp for turning to the left or the right is flashed, and by rotating the control lever in a direction perpendicular to the turn signal position, beam switching or flashing for passing is performed. In this case, the control lever is latched in the operating position, such as the turn signal position or the beam switching position, and is automatically or manually returned to the neutral position when a steering wheel is rotated in a direction opposite to the indicated direction.
Hitherto, a latch mechanism for a control lever has been widely used in which a driving member is slidably held at the base end of the control lever via a spring, and the driving member is pressed into contact with a cross-sectionally V-shaped cam surface that is provided in the housing. In the conventional latch mechanism, a projection is formed in the middle of an inclined surface of the cam surface. By rotating the control lever from the neutral position to the operating position, the driving member slides from a valley to a peak of the cam surface against an urging force of the spring, and the control lever is latched in the operating position at the time the driving member passes over the projection.
According to the conventional latch mechanism, since the control lever is latched in the operating position by locking the driving member with the projection of the cam surface, the control lever cannot be securely latched unless the urging force of the spring for urging the driving member to the cam surface is set to be large. For this reason, the rigidity of the base end of the control lever must be increased by increasing the thickness thereof, and the rigidity of the housing must be increased by increasing the thickness of the cam surface, whereby the overall size of the stalk switch is increased. In addition, since a spring having a large urging force is used, a large amount of force is required to rotate the control lever, and the length between the rotation support and the terminal end of the control lever is necessarily increased, whereby the size of the stalk switch is also increased.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a small stalk switch which can be rotated by a small amount of force.
According to the present invention, there is provided a stalk switch including: a housing having a V-shaped cam surface in cross section; a control lever rotatably supported on the housing; a driving member movably held by the control lever; a first elastic member for urging the driving member in the direction to press into contact with the cam surface; a stopper member disposed so as to be set in and out of a valley of the cam surface; a second elastic member for urging the stopper member in the direction opposite to the direction in which the first elastic member urges the driving member with a force smaller than the force of the first elastic member; an electromagnet capable of attracting an attraction member provided on the stopper member; and a position detecting device for detecting the rotational operation of the control lever from a neutral position to an operating position;
wherein electric current is passed through a coil of the electromagnet by detecting signals from the position detecting device, and the electromagnet attracts the attraction member to hold the stopper member in a projected state during the passage of electric current, whereby the stopper member latches the driving member in the operating position; and
wherein the driving member presses in the stopper member by the urging force of the first elastic member against the urging force of the second elastic member when electric current is not passed through the coil.
With the arrangements, when the control lever is rotated to the operating position, the stopper member is held in a state projected from the valley of the cam surface by the attracting action of the electromagnet, and the driving member is securely latched in the operating position. Therefore, the urging force of the first elastic member can be set to be small, the control lever can be rotated with a small amount of force, and the size of the stalk switch can be reduced.
In the stalk switch of the present invention, the electromagnet may preferably be disposed behind the cam surface, and the stopper member may preferably be passed through the electromagnet.
With the arrangements, not only the size of the control lever, but also the size of the housing can be reduced, whereby the size of the stalk switch is suitably reduced.
In addition, in the stalk switch of the present invention, the position detecting device may preferably be composed of a movable contact provided on the control lever and a fixed contact provided in the housing.
With this arrangement, when the position detecting device is of a contact type, if the movable contact is provided on the control lever, the fixed contact is provided in the housing, and electric current is passed through the coil of the electromagnet based on the ON signal generated when the movable contact comes into contact with the fixed contact, the size of the stalk switch can be reduced. In addition, when the position detecting device is of a magnet type, if the magnet is provided on the control lever, the magnet sensor is provided in the housing, and electric current is passed through the coil of the electromagnet based on the change in outputs from the magnetic sensor when the control lever is rotated to the operating position, the size of the stalk switch can be reduced. In this case, if the magnet and the magnetic sensor are disposed so as to be displaced from each other in the neutral position in the rotation direction of the control lever, the operating positions of the control lever in two different directions can be detected by a common magnetic sensor.
In addition, in the above arrangements, when the control lever is unlatched, the passage of electric current through the coil may be stopped by the output of a steering angle sensor or the like, or the control lever may be manually rotated to the neutral position. Therefore, it is possible to freely set unlatching timing.
REFERENCES:
patent: 2734963 (1956-02-01), Ardia
patent: 4868530 (1989-09-01), Ahs
patent: 5780794 (1998-07-01), Uchiyama et al.
patent: 5886603 (1999-03-01), Powell
Alps Electric Co. ,Ltd.
Brinks Hofer Gilson & Lione
Luebke Renee
LandOfFree
Stalk switch having a latch mechanism for the control lever does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stalk switch having a latch mechanism for the control lever, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stalk switch having a latch mechanism for the control lever will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2588737