JPS6331306Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a limit switch for an electric antenna that connects and separates a contact by sliding a movable contact piece against a fixed contact.

FIG. 1 shows a schematic configuration of a drive mechanism for an electric antenna, in which an antenna 1 is extended and retracted by a wire 2. As shown in FIG. The wire 2 is wound around a drum 3. This drum 3 is driven by a drive motor 4 through a worm 5, a gear 6, and a clutch 7 in forward and reverse rotation.
The wire 2 is fed out or rewound by the rotation of the drum 3. The limit switch 8 cuts off the power to the motor 4 when the antenna 1 is extended or retracted to a predetermined position.The fixed contact 9 of this switch 8 is connected to the motor 4, and the movable contact 10 is connected to the drum 3. The fixed contact 9 is operated to move toward and away from the fixed contact 9 in conjunction with the above.

By the way, as shown in FIG. 2, in a conventional limit switch, a movable contact 10 is arranged to face a fixed contact 9 upwardly and downwardly, and the movable contact 10 moves toward and away from the fixed contact 9 upwardly and downwardly. was configured to do so. Therefore, if dust or the like adheres to the fixed contact 9 or the movable contact 10, poor contact is likely to occur. Furthermore, movable contact 1
Since the limit switch 0 has a structure in which it approaches and separates from the fixed contact 9 upwardly and downwardly, it also has the disadvantage that the height of the entire limit switch becomes high.

Furthermore, as shown in FIG. 3, the movable contact 12 is configured to slide laterally with respect to the fixed contact 11, so that even if dust or the like adheres to the fixed contact 11 or the movable contact 12, the movable contact 12 can be moved to the fixed contact 11. On the other hand, there are some devices that use sliding contact to remove dust, etc., prevent poor contact, and reduce the height dimension, but in this case, there is a drawback that positioning of the movable contact 12 becomes difficult. Further, in order to maintain the state in which the movable contact 12 is in contact with the fixed contact 11, it is necessary to provide a special holding member, which poses a problem of complicating the structure.

This idea was made based on these circumstances, and its purpose is to easily remove dust etc. that adheres between the fixed contact and the movable contact piece as the movable contact piece moves. The height dimension can be reduced, and the movable contact piece can be easily positioned.In addition, the simple structure ensures that the movable contact piece maintains its position when the fixed contact is energized. An object of the present invention is to provide a limit switch for an electric antenna, which can be used to control electric antennas.

That is, as shown in FIGS. 4 to 6, the electric antenna limit switch of this invention includes a switch body 23 having a pair of fixed contacts 21, 21 at one end and a stopper portion 22 at the other end; A movable contact piece 24 is pivotally supported on the switch body 23 and rotates while slidingly contacting the fixed contacts 21, 21 within a range limited by the stopper portion 22, and is appropriately separated from one or the other contact; A rotating member 26 that rotates forward and backward in conjunction with the feeding or retracting operation of the rotating member 26 has a pressing protrusion 28 on one part and a smooth surface 29 on another part, so that the rotational force of the rotating member 26 is frictionally transmitted. The smooth surface 29 is slidably contacted with the movable contact piece 24, and the rotation of the rotating member 2 is prohibited while the contact piece 24 is prevented from rotating.
6, and after removing the smooth surface 29 from the contact piece 24, the switch switching member 30 rotates the contact piece 24 by the pressing protrusion 28.

A support shaft 25 is provided protruding from the other end of the switch body 23. Note that this support shaft 25 may be provided on a frame 37, which will be described later. The rotating member 26 has a plurality of protrusions 31 protruding from the outer periphery, and a second
In conjunction with the drum 3 shown in the figure, the protrusion 31 is rotated by one projection each time the drum 3 rotates once. Further, a cylindrical support shaft 32 that rotatably fits into the support shaft 25 is attached to the center of the rotating member 26. The switching member 30 is rotatably fitted onto this support shaft 32 . In this case, at the contact portion between the rotating member 26 and the switching member 30, the rotating member 26 has a plurality of protrusions 33...
A plurality of recesses 34 are provided in the switching member 30, and the rotation of the rotating member 26 is reliably transmitted to the switching member 30 by fitting these protrusions 33 and recesses 34. It turns out. The switching member 30 is held in pressure contact with the rotating member 26 by a spring 35. An escape groove 36 is provided between the pressing projection 28 and the smooth surface 29 of the switching member 30. The switch body 23 is attached to a frame 37 with a switching member 30, a rotating member 26, etc. integrally attached to a support shaft 25.

On the other hand, the movable contact piece 24 is shaped like a leaf spring, and has a pair of bent portions 3 bent at a substantially right angle at one end.
8, 38 are provided, and these bent portions 3
Either one of 8 and 38 comes into contact with the pressing protrusion 28 when the switching member 30 rotates. The movable contact piece 24 is rotatably attached to the switch main body 23 by a screw 39, and one end of this contact piece 24 is attached to the fixed contact 23.
1 and 21.

Next, the operation of the limit switch configured as described above will be explained. First, as shown in FIG.
When the switching member 30 is rotated by a predetermined angle by a biasing means (not shown) from the position where the switch member 4 is in the position where the current is cut off between the fixed contacts 21 and 21, the movable contact piece 24 is pushed against the inclined surface 40 of the relief groove 36. fixed contact 2
Rotate to the position where 1 and 21 are connected. Then, the motor 4 is driven and the antenna 1 is extended or retracted. At this time, as the drum 3 rotates, the rotating member 26 and the switching member 30 are integrally rotated in one direction intermittently. When the antenna 1 is extended or retracted to a predetermined position, one bent portion 38 of the movable contact piece 24 is pressed against the stopper portion 22 by the pressing protrusion 28 of the switching member 30, and the movable contact piece 24 is rotated. Then, the connection between the fixed contacts 21 and 21 is broken. Note that even if the motor 4 rotates excessively after the movable contact piece 24 is pressed against the stopper portion 22, the rotation member 26 rotates idly relative to the switching member 30, so that the excess rotation amount of the motor 4 is absorbed. will be done.

As explained above based on the embodiments, the electric antenna limit switch of this invention has a structure in which the movable contact piece slides against the fixed contact, so that dust cannot be deposited on the fixed contact or the movable contact piece. Even if dust etc. adheres, the movable contact piece can easily remove the dust etc. as the movable contact piece moves, and as a result, poor contact etc. can be prevented. Moreover, the overall height dimension can be reduced. Furthermore, after the rotating member presses the movable contact piece against the stopper part, the rotating member idles relative to the switch switching member.
The stopping position of the movable contact piece can be easily and accurately positioned. In addition, when the fixed contact is energized, the other end of the movable contact piece is in sliding contact with the smooth surface of the switch switching member, so this smooth surface prevents the movable contact piece from tilting. This configuration allows the movable contact piece to be held in position reliably.

It should be noted that this invention is not limited to the above-mentioned embodiments, and of course can be modified in various ways. For example, the rotating member 26 and the switch switching member 3
0 and an insert having a large friction coefficient may be inserted.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the schematic configuration of an electric antenna, Fig. 2 is a side view showing a conventional example, and Fig. 3 is an explanatory diagram showing a schematic configuration of an electric antenna.
Plan views showing conventional examples different from those shown in the figure, Figures 4 to 6
The figure shows one embodiment of this invention.
is an exploded perspective view of the whole, FIG. 5 is a partial perspective view, FIG. 5 is a front view, and FIG. 6 is a side sectional view. 21...Fixed contact, 22...Stopper part, 23
...Switch body, 24...Movable contact piece, 26...
...Rotating member, 28...Press projection, 29...Smooth surface, 30...Switch switching member.

Claims (1)

[Scope of utility model registration request] A switch body has a pair of fixed contacts at one end and a stopper section at the other end, and the switch body is pivotally supported by the switch body and rotates while slidingly contacting the fixed contacts within a range limited by the stopper section. or a movable contact piece that is appropriately spaced apart from the other contact, a rotating member that rotates forward and backward in conjunction with the extending or retracting operation of the antenna, and a pressing protrusion in one part and a smooth surface in another part. The rotating member is provided so that the rotational force of the rotating member is transmitted by friction, and the smooth surface is brought into sliding contact with the movable contact piece to rotate following the rotating member while inhibiting rotation of the contact piece. A limit switch for an electric antenna, comprising a switch switching member that rotates the contact piece by a pressing protrusion after removing the contact piece from the contact piece.