JP3610725B2 - Limit switch - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a limit switch used for electrical equipment and electronic equipment.
[0002]
[Prior art]
Conventionally, a limit switch described in Japanese Patent Laid-Open No. 59-26843 is known. FIG. 5 is a perspective view of a compact disc loading mechanism using a conventional limit switch. Reference numeral 1 denotes a loading mechanism body of a compact disc (hereinafter abbreviated as a CD), and 2 denotes a CD tray on which a CD is placed. The CD tray 2 is provided with push ribs 2a. The conventional limit switch 3 is attached to the loading mechanism body 1.
[0003]
Although not shown in detail, the loading mechanism main body 1 has a mechanism for playing a CD, a loading mechanism for pushing the CD tray 2 in the direction of the arrow X so that a CD can be placed, or a CD that has been played can be replaced. ing. By this loading mechanism, the CD tray 2 housed in the loading mechanism main body 1 is pushed out in the direction of arrow X, and the pushing rib 2a as the operating portion pushes the turning lever 4 of the limit switch 3. Then, the connection terminal of the limit switch 3 changes to a conductive state, that is, changes from the OFF state to the ON state, so that it can be electrically detected that the CD tray 2 has been pushed out to a predetermined position, and the loading mechanism is stopped. It is configured to be able to.
[0004]
6 is an enlarged perspective view of a conventional limit switch 3, and FIG. 7 is an exploded perspective view thereof. The main body 5 has holes 5a and 5b for holding the rotation support shafts 4b and 4c of the rotation lever 4 at the upper part of one end of both side surfaces which are long sides, and covers on both side surfaces which are short sides. 8 has protrusions 5c and 5d for locking the eight holes 8b and 8c. Connection terminals 6 and 7 made of a conductive material are provided as separate members at the bottom of the main body 5. The connection terminal 6 has a foot 6a for connecting to the wiring board and a contact surface 6b, and the connection terminal 7 has three legs 7a, 7b, 7c and a contact surface 7d for connecting to the wiring board.
[0005]
The rotation lever 4 has a tip end portion 4a having a width dimension A, rotation support shafts 4b and 4c, and a stopper portion 4d. At the lower part of the rotating lever 4, a contact piece 9 made of a conductive and spring material is provided as a separate member, and the tip of the contact piece 9 is branched into plate spring portions 9a and 9b.
[0006]
The cover 8 is bent in a U-shape, and has a rectangular hole 8a extending in the long side direction in order to insert the rotation lever 4 substantially in the center, and the convex portions 5c and 5d of the main body 5 on the side surface of the short side. Have holes 8b and 8c for engaging with.
[0007]
Next, a method for assembling the conventional limit switch 3 will be described. First, the rotation support shafts 4 b and 4 c of the rotation lever 4 are inserted into the holes 5 a and 5 b of the main body 5. Then, the rotation lever 4 becomes rotatable around the holes 5a and 5b of the main body 5 as bearings. Next, the end portion 4a of the rotating lever 4 is passed through the hole 8a of the cover 8, and the assembly is completed by engaging the convex portions 5c and 5d of the main body 5 with the holes 8b and 8c of the cover 8. After assembling, the rotating lever 4 is pushed upward by the spring properties of the leaf spring portions 9a and 9b of the contact piece 9 provided at the lower portion, but the stopper portion 4b of the rotating lever 4 hits the inner surface of the cover 8, The moving lever 4 stops at a predetermined angle. At this time, the plate spring portions 9 a and 9 b of the contact piece 9 are both in contact with the connection surface 7 d of the connection terminal 7. Therefore, the connection terminals 6 and 7 are not yet in a conductive state.
[0008]
As described with reference to FIG. 5, when the pushing rib 2a of the CD tray 2 pushes the tip 4a of the turning lever 4 in the arrow X direction, the turning lever 4 is centered on the holes 5a and 5b of the main body 5. Rotate clockwise. Then, the contact piece 9 moves with the rotation of the rotation lever 4, and the leaf spring portion 9 a of the contact piece 9 moves from the contact surface 7 d of the connection terminal 7 to the contact surface 6 b of the connection terminal 6. The leaf spring portion 9 b of the contact piece 9 remains in contact with the contact surface 7 d of the connection terminal 7. Therefore, the connection terminals 6 and 7 are brought into conduction through the leaf spring portions 9a and 9b of the contact piece 9.
[0009]
[Problems to be solved by the invention]
In FIG. 5, when the push rib 2a which is the operating portion of the CD tray 2 pushes the tip portion 4a of the rotation lever 4, if the limit switch 3 or the push rib 2a of the CD tray 2 is displaced in the arrow Y direction, The push rib 2a may not press the tip 4a of the rotation lever 4, and the limit switch 3 is not turned on. Therefore, this problem is usually solved by increasing the width of the push rib 2a. However, in the case of a resin-molded CD tray 2, the width of the push rib 2a formed in a T-shape from the back of the tray 2 is used. If the width of the tray 2 is widened, the surface of the tray 2 will have a “sink” in the shape of a dimple, so it cannot be made wider than necessary. On the other hand, since the limit switch 3 is assembled by passing through the hole 8a of the cover 8, the width dimension A of the distal end portion 4a of the rotating lever 4 cannot be increased more than necessary.
[0010]
Therefore, as shown in FIG. 8, the cap 13 as a separate member is fixed to the distal end portion 4 a of the rotation lever 4 of the limit switch 3, and the width dimension B is increased to solve this problem. The limit switch is very expensive as a limit switch because the cap 13 which is a separate member is required and an operation of fixing the cap 13 to the distal end portion 4a of the rotating lever 4 occurs.
[0011]
It is an object of the present invention to provide an excellent limit switch that can widen the tip of a rotating lever without using a separate member called a cap, and can reliably turn on the switch even if there is a slight misalignment. It was made as a purpose.
[0012]
[Means for Solving the Problems]
In order to solve this problem, a limit switch according to the present invention includes a main body having two connection terminals and a connection between the connection terminals attached to the main body and rotatable with respect to the main body. A rotating lever having a contact piece for conducting or non-conducting, and a cover having a hole through which the rotating lever is inserted substantially at the center and configured to cover the periphery of the rotating lever when attached to the main body. The pivot lever has a tip that bends and widens in a direction perpendicular to the pivot direction, and has an insertion end through which the hole in the cover is inserted, and the hole in the cover is inserted through the insertion end and rotated to the attachment position on the main body. The width of the rotary lever in the cross section including the rotary shaft of the rotary lever during the movement is formed to be smaller than the width in the cross section of the hole of the cover.
[0013]
With this configuration, even if the tip of the rotating lever is wide, the cover hole can be inserted into the main body while rotating through the insertion end of the rotating lever, and the tip of the rotating lever is wide. Therefore, the limit switch can be moved reliably even if the operating portion on the device side is narrow or there is a slight displacement.
[0014]
According to a second aspect of the present invention, in the configuration of the first aspect, the rotation lever has a vertical surface formed at the center of the width of the two rotation support shafts and a vertical surface formed at the center of the rotation lever tip bent at a right angle. The surface is substantially coincident with the surface, and this configuration has an effect of reducing the occurrence of twisting when the distal end portion of the rotating lever is pushed by the operating portion on the device side.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
(Embodiment 1)
FIG. 1 is an exploded perspective view of a limit switch 11 according to a first embodiment of the present invention, and the same components 5, connection terminals 6, 7, cover 8, and contact piece 9 are the same as those in the conventional example. A detailed description is omitted with reference numerals. What is different from the component parts of the conventional limit switch 3 is a rotating lever 10, which has a configuration in which the tip end portion 10 a is bent in a direction perpendicular to the rotating direction and has a widened surface. And thereby, the width dimension B of the front-end | tip part 10a can be made larger than the width dimension A near rotation center. Further, the width dimension of the tip base portion 10e of the rotation lever 10 is smaller than the width dimension A near the rotation center. Further, the rotation support shafts 10 b and 10 c and the stopper portion 10 d have the same shape as the conventional rotation lever 4.
[0017]
As shown in the side view of FIG. 2, the assembly method is as follows. While rotating clockwise, lower it downward. The width of the distal end base portion 10e of the rotating lever 10 on the surface of FIG. 2, that is, the surface including the rotating shaft of the rotating lever 10, is smaller than the dimension A, and for mounting from the distal end portion 10a to the mounting position. If the width of the cross section of all the portions of the cover 8 during rotation is narrower than the width C of the hole 8a, the tip portion 10a and the tip base portion 10e of the rotation lever 10 are skillfully formed in the hole 8a of the cover 8. The projections 5c and 5d of the main body 5 and the holes 8c and 8d of the cover 8 are engaged with each other and assembled. With such a configuration, the tip portion 10a having a width wider than the width C of the hole 8a is inserted into the hole 8a, and it is possible to assemble using components similar to those of the conventional example except for the rotating lever 10.
[0018]
The limit switch 11 configured as described above operates in the same manner as the conventional limit switch 3 by pushing the tip end portion 10a of the rotation lever 10 against the push rib 2a of the CD tray. When the leaf spring portion 9a of the contact piece 9 provided in the lower portion of the turning lever 10 contacts the contact surface 6b of the connection terminal, the connection terminals 6 and 7 are connected to the plate of the contact piece 9. A conductive state is established via the spring portions 9a and 9b.
[0019]
As described above, according to the present embodiment, the cap 10 of the separate member as in the conventional example can be provided by simply having the front end portion 10a of the rotation lever 10 with a surface that extends in a direction perpendicular to the rotation direction. Without use, the width dimension of the tip 10a of the rotating lever 10 can be increased.
[0020]
(Embodiment 2)
Next, FIG. 3 shows the turning lever 12 of the limit switch of the second embodiment. The other components of the limit switch are the same as those of the first embodiment, and the same reference numerals are given and description thereof is omitted.
[0021]
The difference between the turning lever 12 of the present embodiment and the turning lever 11 of the first embodiment is the positions of the distal end portion 12a and the distal end root portion 12e. The front end portion 12a has a width dimension B and is the same as that of the first embodiment, but the entire surface is translated in the direction of the rotation center. That is, in the rotation lever 12, the vertical surface formed in the center of the surface of the front end portion 12a and the vertical surface formed in the center of the widths of the two rotation support shafts 12b and 12c are substantially matched. For this reason, the tip root portion 12e is curved outward as shown in the figure, and its width dimension is smaller than the width dimension A in the vicinity of the rotation center, as in the first embodiment. Then, as in the first embodiment, the cover 8 is made vertical to approach the front end portion 12a of the lever 12 from the lateral direction, the insertion end 12f of the front end portion 12a is passed through the hole 8a of the cover 8, and the cover 8 is counterclockwise. What is necessary is just to assemble | assemble by lowering downward, rotating in a direction.
[0022]
The limit switch configured as described above operates in the same manner as in the first embodiment, when the tip end portion 12a of the rotating lever 12 is pushed by the pushing rib 2a of the CD tray, so that the rotating lever 12 rotates. When the leaf spring portion 9a of the contact piece 9 provided in the lower portion comes into contact with the contact surface 6b of the connection terminal, the connection terminals 6 and 7 become conductive. At this time, even if the pushing rib of the CD tray pushes the front end portion 12a of the rotating lever 12, the vertical surface formed at the center of the surface of the front end portion 12a and the vertical formed at the center of the width of the two rotating support shafts 12b and 12c. Since the surface is configured to substantially coincide with the surface, the rotation lever 12 can be rotated without being twisted by the pressing force of the pressing rib 2a of the CD tray.
[0023]
In the first and second embodiments, the push rib that pushes the limit switch pivot lever is the CD tray push rib 2a. However, the same effect can be obtained not only with the CD tray but also with any electric device or electronic device. Needless to say,
[0024]
【The invention's effect】
As described above, according to the limit switch of the present invention, the width of the distal end portion of the rotating lever can be increased without using a cap of another member as in the conventional example. Even if the tip of the rotating lever is wide, the hole in the cover can be inserted through the insertion end of the rotating lever and attached to the body while rotating. The tip of the rotating lever has a wide surface. Therefore, even if the operating portion on the device side is narrow, there is an advantageous effect that the limit switch can be operated reliably even if there is some positional deviation.
[0025]
According to the second aspect of the present invention, it is possible to reduce the occurrence of torsion when the distal end portion of the rotating lever is pushed by the operating portion on the equipment side.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a limit switch according to a first embodiment of the present invention. FIG. 2 is an explanatory side view of the cover attached state. FIG. 4 is a perspective view of a CD loading mechanism as an example of use of a conventional limit switch. FIG. 6 is an external perspective view of a conventional limit switch. Fig. 8 is an exploded perspective view of the conventional limit switch with a cap attached.
5 Main body 6, 7 Connection terminal 8 Cover 9 Contact piece 10, 12 Rotating lever 10 a, 12 a Rotating lever tip 10 b, 10 c Rotating support shaft 10 e, 12 e Rotating lever tip root 10 f, 12 f Insertion end 11 Limit switch

Claims (2)

A main body having two connection terminals;
A rotation lever having a contact piece attached to the main body and capable of rotating with respect to the main body and making the connection terminals conductive or non-conductive with rotation;
A cover having a hole through which the rotation lever is inserted substantially at the center and configured to cover the periphery of the rotation lever when attached to the main body;
The pivot lever has a distal end portion which is bent and widened in a direction perpendicular to the pivot direction, and has an insertion end through which the hole of the cover is inserted. The width of the rotation lever in the cross section including the rotation axis of the rotation lever during rotation to the position is formed to be smaller than the width in the cross section of the hole of the cover, and can be attached to the main body. A limit switch characterized by The rotating lever is configured so that the vertical surface formed at the center of the width of the two rotating support shafts and the vertical surface formed at the center of the bent portion at the right end of the rotating lever substantially coincide. The limit switch according to claim 1, wherein:

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