JPH0215230Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) This invention relates to a limit switch in which a reed switch is opened and closed by a shielding plate made of a magnetic material that tilts in conjunction with an operating lever.

(Prior art) Conventionally, this type of limit switch was developed in U.S. Pat.
This is shown in Publication No. 134265. That is, a switch unit fixed to a case is formed into a U-shape, a reed switch is housed in one leg of the switch unit, a permanent magnet is housed in the other leg to close the reed switch, and the reed switch is closed in the case. The reed switch was configured to open the reed switch by blocking the magnetic field acting on the reed switch by a shielding plate made of a magnetic material interlocked with a pivoted operating lever.

(Problem that the invention aims to solve) However, in the conventional product, the shielding plate that passes between the legs of the switch unit is fixed to the operating shaft that rotates together with the operating lever, and it cannot be moved far from this fixed part. The tip of the switch unit is curved and comes into contact with or collides with the leg of the switch unit, resulting in damage to the switch unit or malfunction. Additionally, because the shielding plate moves at the same angle as the operating lever, it has a wide range of motion, resulting in larger products and shapes.

[Means to solve the problem]

Therefore, this invention reduces the movement of the shield plate by inserting a link mechanism between the operating lever and the shield plate, and stabilizes the operating characteristics.
It is an object of the present invention to provide a limit switch of this type which can be constructed compactly and whose shielding plates do not cause collisions during operation.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

In FIGS. 1 to 3, 1 is a case, 2 is a cover, 3 is a support provided on the case, 4 is a support metal fitting formed in a U-shape and whose connecting portion is fixed to the support with screws 5; 6 and 7 are the legs 4 of the support fitting 4
A and 4b are fixed to the switch unit, which is formed into a U-shape and has a reed switch (not shown) housed in one leg 6a and 7a, and a permanent magnet (not shown) housed in the other leg 7b. The reed switch (not shown) is configured to open the circuit.

Reference numeral 8 denotes an operating shaft supported by bearings 9, 9 fixed to the case 1, and an operating lever 10 is provided on a portion protruding from the case. 11 is a tilting plate fixed to the operating shaft 8; 12 is a support rod fixed between the support stands 3; and an engaging portion in the middle thereof that engages with a notch groove of a guide rod 13, which will be described later. 12a is provided. 13 is a guide rod, with a boss 13a at one end
is provided in the boss 13a, and a pin 14 is provided in the insertion hole 13b.
is inserted and fixed to the tilting plate 11 so as to be rotatable, and a notch groove 13c is provided at the other end, and the notch groove 13c is engaged with the engaging portion 12a of the support rod 12. A spring 15 is inserted through the guide rod 13, one end of which is engaged with the boss 13a of the guide rod, and the other end is locked with the support rod 12 via a washer 16.

Reference numeral 17 denotes a lever pivotally supported on the support rod 12 so that it can be tilted, and 18 is a shielding plate made of a magnetic material that is supported on the tilting plate 11 through a pin 19 so that it can be tilted. Shielding parts 18a and 18b are provided on both sides of the shielding plate, which are pivotally supported via a pin 20 and are inserted between the leg parts of the switch units 6 and 7, on both sides of the shielding plate of a line connecting pins 19 and 20.

〔motion〕

FIG. 1 shows a state in which a reed switch (not shown) built in one switch unit 7 is open, and a reed switch (not shown) built in the other switch unit 6 is closed. From this state, when the operating lever 10 is rotated counterclockwise about the operating shaft 8, the spring 1 inserted through the guide rod 13
The tilting plate 11 is integrated with the operating shaft 8 against the spring force of 5.
Rotate counterclockwise.

As a result, the lower part of the shielding plate 18 supported by the tilting plate rotates counterclockwise together with the tilting plate, and the pin 2 is attached to the lever 17 pivoted on the support rod 12.
The upper part of the shielding plate supported by the lever 17 rotates counterclockwise about the support rod as a fulcrum, and the combined operation of these rotations causes the upper part of the shielding plate 18 to be rotated together with the lever 17.
move the entire area. When the operating lever is further rotated counterclockwise, when the center of the boss of the guide rod that supports one end of the spring 15 crosses the line connecting the axis of the operating shaft 8 and the center of the support rod 12, the energy accumulates in the spring 15. The tilting plate is rotated counterclockwise by the applied spring force.

Therefore, the lower part of the shielding plate 18 supported by the tilting plate rotates counterclockwise together with the tilting plate, and the upper part of the shielding plate 18 has the center of the boss of the guide rod supporting the spring at the operating shaft 8. Rotate counterclockwise around the support rod until it passes the axis of the operating shaft and the center of the support rod 12, and when the center of the boss of the guide rod passes the axis of the operating shaft and the center of the support rod 12, rotates clockwise around the support rod, moves the entire shielding plate, and as shown in FIG.
A reed switch (not shown) stored in one leg of the permanent magnet (not shown) stored in the other leg.
The shielding part 17a closes due to the magnetic field of
is inserted between the legs of the switch unit 6, and shields the magnetic field of a permanent magnet (not shown) housed in the other leg that acts on a reed switch (not shown) housed in one leg of the switch unit 6. The reed switch is opened by being blocked by the shielding portion 18a of the plate.

Therefore, the lower part of the shielding plate 18 is supported by a tilting plate provided on the operating shaft 10, and the upper part is pivotally supported by a support rod via the lever 17, so that the shielding part of the shielding plate can be smoothly inserted and removed between the legs of the switch unit. do.

Although the illustrated embodiment shows the case where two switch units are provided, the present invention is not limited to this, and one switch unit may be provided. Further, the end of the shielding plate may not be completely removed from between the legs of the switch unit, but may be partially exposed.

[Effect of idea]

In this device, a switch unit has a reed switch housed in one leg and a permanent magnet in the other leg, and the lower part of the shielding plate made of magnetic material is inserted between the legs and removed, and the upper part is attached to a tilting plate fixed to the operating shaft. Since it is attached to the support rod via the lever, the shielding plate operates smoothly without colliding with or sliding against the leg side of the switch unit, and the switch can be opened and closed reliably. Further, since the shielding plate is moved laterally, the operating range of the shielding plate is reduced, and a compact limit switch can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cut-away front view of an embodiment of this invention, FIG. 2 is a partially cut-away side view thereof, and FIG. 3 is a partially cut-away front view of an embodiment of the invention. 1... Case, 2... Cover, 3... Support stand,
4...Support fitting, 5...Screw, 6 and 7...Switch unit, 8...Operation shaft, 9...Bearing, 10
...Operation lever, 11...Tilt plate, 12...Support rod, 13...Guide rod, 14...Pin, 15...Spring, 16...Washer, 17...Lever, 18...Shielding plate, 19 and 20...pin.

Claims (1)

[Scope of utility model registration request] A switch unit is attached to the case and has a reed switch housed in one leg and a permanent magnet for operating the reed switch in the other leg. In the limit switch which opens and closes the reed switch by inserting and removing the reed switch and interrupting the magnetic field of the permanent magnet acting on the reed switch of the switch unit, a tilting plate is provided on the operating shaft, and one of the shielding plates is pivoted to the tilting plate. , the other being supported via a link lever pivoted to the case so that the entire shielding plate can be moved.