The present invention relates to a push switch that uses a reed switch.
With a push switch that uses a reed switch, magnetic flux of a permanent magnet is applied to a pair of reeds of the reed switch to magnetize them, making them contact each other by magnetic attraction force to turn on the switch, and making the permanent magnet get away or forming a magnetic path with an auxiliary magnetic body and thus allowing the contact point of the reeds to get away from each other to turn off the switch. ON-OFF switching is performed by allowing the permanent magnet to get away from or come close to the reed switch from outside, or as in the case of a microswitch mechanism disclosed in Patent Literature 1, by allowing a permanent magnet to get away from or come close to the reed switch by the restoring force of an elastic member such as a spring.
However, in the ON state of the push switch using a known reed switch, one reed only is magnetized by the permanent magnet, whereas the other reed is not magnetized by the permanent magnet, which is why the ON state cannot be maintained stably. In addition, the OFF state is generated as a result of the reeds losing magnetism. Known push switches thus become instable due to the effect of external magnetic fields, vibration, etc., and so their reliability as a push switch is low.
The above-mentioned push switch that uses a reed switch also requires an elastic member to return the permanent magnet having been operated to the original position and parts for supporting this elastic member, etc., and so the elastic member is required to have sufficient mechanical durability.
In view of such circumstances, the present invention intends to provide a push switch having a reed switch that is in a simple structure yet has high reliability and durability.
To achieve the above objective, a push switch of the present invention comprising:
Preferably, the case is positioned with respect to the reed switch so that the contact point of the reed witch comes at the center between the first magnet and the second magnet in the non-operating state (see
Meanwhile, when the pushing member is pressed down, the second magnet moves to an operating position close to the first magnet, coming near the contact point of the reed switch. As the result, the lower reed of the reed switch maintains the state magnetized by the first magnet, whereas the upper reed is magnetized to the opposite pole by the second magnet, both reeds being attracted to each other and thus turning on the reed switch (see
In the above configuration, it is also possible to place the case with respect to the reed switch so that the position near the contact point of the reed switch comes close to the center between the first magnet and the second magnet in the axial direction in the operating state (see
With the normally-closed type push switch, once the pushing member is manually pressed down, the second magnet moves to the operating position close to the first magnet, namely close to the contact point of the reed switch. Accordingly, the pole of the upper reed near the contact point reverses to the same pole as the lower reed. Since the reeds are thus separated from each other due to magnetic repulsive force, the reed switch is turned off (see
In this case, the pushing member is released, the second magnet and the pushing member move upward due to magnetic repulsive force between the first magnet and the second magnet, returning to the non-operating state. Therefore, an elastic material for returning the second magnet and the pushing member to the non-operating state is unnecessary.
With the present invention, the contact point of the reed switch preferably comes either at a first position, where the contact point is near the center between the first magnet and the second magnet in the non-operating state, or at a second position, where the contact point is near the center between the first magnet and the second magnet in the operating state (shown in
The magnetic body is preferably provided at a position of the base that abuts against the first magnet (shown in
According to the present invention, a push switch that uses a simple-structure and high-reliability/durability reed switch can be provided.
The embodiment of the present invention will hereinafter be described in detail by referring to drawings. The scope of the present invention is not limited to the embodiments described but can be changed as required. The same signs are assigned to the same or corresponding members, etc. in each drawing.
Embodiment 1 shown in
The base 11 is made of a nonmagnetic material such as resin and aluminum, for example, and houses the reed switch 16. The base 11 comprises, in the case shown, an approximately cylindrical main body 11a and a cylindrical reed switch accepting part 11b that extends upward from the center on the top face of the main body 11a along the central axis O. The reed switch accepting part 11b has a hollow structure that penetrates downward along the above-mentioned central axis O, houses the reed switch 16 inside, and reed wires 16c, 16d of the reed switch 16 are drawn out from the bottom to outside. The reed wires 16c, 16d are made of a nonmagnetic material such as copper and aluminum, for example. The tips of a pair of reeds 16a, 16b, which close by contacting each other due to external magnetic field to be described later, are called a contact point.
The base 11 has two cutouts 11c, 11d, which are arranged alternately at equal angular intervals on the outer periphery and have different heights. The cutouts 11c, 11d are arranged alternately at intervals of about 90 degrees in the circumferential direction as shown in
The case 12 is made of a nonmagnetic material such as resin and aluminum for example, formed in a hollow cylindrical shape around the central axis O, with a through hole 12a provided at the center of its top end. This case 12 has an annular flange 12b that protrudes inwards near the bottom end. The inner periphery of this flange 12b has a diameter slightly larger than the outer diameter of the reed switch accepting part 11b of the base 11 described above. The hollow case 12 is supported by the base 11, and is arranged so as to surround the reed switch 16 around the central axis. In a non-operating state where the pushing member 15 is not pressed down, the case 12 is positioned with respect to the reed switch 16 so that the contact point of the reeds 16, 16b of the reed switch 16 comes at the center between the first magnet 13 and the second magnet 14 in the axial direction. The central axis O of the base 11 practically coincides with the above-mentioned central axis of the reed switch 16, and each central axis of the reed switch 16, case 12, first magnet 13, and second magnet 14 coincides with the central axis O of the base 11, and the central axis O of the base 11 can thus be called the central axis of the push switch 10 of the present invention.
Furthermore, the case 12 has a cutout 12c at the bottom end that corresponds to the cutout 11d of the base 11 to select its position. In a state as shown in
Meanwhile, if the case 12 is fitted onto the base 11 in a state where the case 12 is rotated by 90 degrees around the central axis O from the state shown, the bottom face of the case 12 abuts against the cutout 11d of the base 11 as shown in
As shown in
The second magnet 14 is in the same configuration with the first magnet 13, and as shown in
The pushing member 15 is made of a nonmagnetic material such as resin and aluminum, and includes a flat and hollow cylindrical main body 15a and protrusion 15b that extends upward from the top center of the main body 15a along the central axis O. The main body 15a of the pushing member 15 has a diameter smaller than the inner diameter of the case 12, and its bottom face is fastened to the top face of the second magnet 14 using an adhesive agent, etc. The protrusion 15b of the pushing member 15 is exposed to outside through the through hole 12a at the top end of the case 12.
The first magnet 13 and the second magnet 14 are magnetized in a direction opposite to each other, which generates magnetic repulsive force between the first magnet 13 and the second magnet 14. As shown in
In this non-operating state, the protrusion 15b of the pushing member 15 is in a state sufficiently protruding from the top face of the case 12. In this non-operating state, the top face of the flange of the main body 15a may abut against the inner side of the top face of the case 12 to regulate the upward movement of the pushing member 15 and the second magnet 14. If the protrusion 15b of the pushing member 15 is pressed down, the pushing member 15 and the second magnet 14 move downward, against the above-mentioned repulsive force, to the position where the bottom face of the second magnet 14 abuts against the top face of the first magnet 13, namely the operating position.
The reed switch 16 is arranged within the reed switch accepting part 11b of the base 11 so that its longitudinal direction comes along the central axis O and its pair of reeds 16a, 16b are positioned close to the central axis O, and has reed wires 16c, 16d extending from the reeds 16a, 16b.
As shown in
First, the state where the case 12 of the push switch 10 in the embodiment of the present invention is at the first position with respect to the base 11 will be described mainly by referring to
In this case, the lower reed 16a of the reed switch 16 is magnetized to become N pole by the magnetic effect of the first magnet 13, and the upper reed 16b is magnetized to become N pole by the magnetic effect of the second magnet 14. Since the reeds 16a, 16b of the reed switch are magnetized to become the same pole, magnetic repulsion occurs between them, thus turning off the reed switch 16. Since both reeds 16a, 16b are respectively magnetized by the first magnet 13 and the second magnet 14, and the contacts are apart from each other, the OFF state is maintained stably and insusceptible to the external impact such as magnetic fields and the vibration.
As shown in
Next, the state where the case 12 is at the second position with respect to the base 11 will be described by referring to
As a result, the lower reed 16a of the reed switch 16 is magnetized to become S pole by the magnetic effect of the first magnet 13, whereas the upper reed 16b is magnetized to become N pole by the magnetic effect of the first magnet 13. Consequently, the reeds 16a, 16b of the reed switch are magnetized to opposite poles, thus being attracted to each other magnetically and turning on the reed switch 16. At the second position, while the pushing member 15 is in non-operating state, the both reeds 16a, 16b are respectively magnetized by the magnetic force of the first magnet 13 only, and thus the ON state is maintained stably and insusceptible to external impact such as magnetic fields and the vibration.
As shown in
Since the reeds 16a, 16b are magnetized to the same pole and thus magnetically react and come away from each other, the reed switch 16 is turned off. Since the both reeds 16a, 16b are respectively magnetized by the first magnet 13 and the second magnet 14, the OFF state is maintained stably and insusceptible to external impact such as magnetic fields and the vibration. While the case 12 is at the second position with respect to the base 11, the reed switch 16 thus comes on in the non-operating state, and comes off in the operating state, functioning as a so-called normally-closed type switch.
The above push switch 10 may have a magnetic body at a position of the base 11 abutting against the first magnet 13. Specifically, the magnetic body 17 may be mounted on the upward end face of the cutouts 11c, 11d of the base 11. In this case, the magnetic body 17 is attracted by the magnetic attraction force of the first magnet 13 to abut against the cutouts 12c or 12d of the case 12, facilitating maintaining normally-open first position and normally-closed second position by bonding between the magnetic body 17 and the first magnet 13. By mounting the magnetic body 17 on the base 11 of the push switch 10 capable of switching between normally-open and normally-closed states according to the present invention, the base 11 can be prevented from coming off the case 12 by using the attraction force of the first magnet 13 embedded in the case 12. It is also allowed to use a magnet, in addition to a magnetic sheet, as the magnetic body 17 to enhance attraction force to prevent the base 11 from coming off the case 12, ensuring switching between normally-open and normally-closed states.
A push switch according to embodiment 2 will hereinafter be described by referring to
With the push switch 20 according to embodiment 2, as in the case of embodiment 1, the case 12A is positioned with respect to the reed switch 16 so that the contact point of the reed switch 16 comes close to the center point between the first magnet 13 and the second magnet 14 in the non-operating state. Consequently, as shown in
With this push switch 20, the OFF state and ON state of the reed switch 16 are maintained stably and insusceptible to external impact such as magnetic fields and vibration, as in the case of the push switch 10 where the case 12 is at the first position with respect to the base 11.
A push switch according to embodiment 3 will hereinafter be described by referring to
With the push switch 30 according to embodiment 3, as in the case of embodiment 1, the case 12B is positioned with respect to the reed switch 16 so that the contact point of the reed switch 16 comes close to the center point between the first magnet 13 and the second magnet 14 in the operating state. As in the case of push switch 10, the reed switch 16 of the push switch 30 remains on in the non-operating state (see
The present invention can be executed in various embodiments without departing from the scope of the present invention. For example, the outer periphery of the reed switch accepting part 11b of the base 11 can be in a shape other than cylindrical shape. Although the inner periphery of the case 12 is in cylindrical shape, other shapes are also allowed. The shape of the outer periphery of the reed switch accepting part 11b and the inner periphery of the case 12 may be selected arbitrarily, provided that the second magnet 14 and the pushing member 15 are vertically movable freely.
The push switches 10, 20, 30 of the present invention are applicable to various fields such as working machines and various manufacturing systems, and can be used by attaching not only in vertical direction but also in horizontal direction.
In embodiment 1 described above, the cutouts 11c, 11d on the upper side of the outer periphery of the base 11 and the cutout 12c on the bottom edge of the case 12 are provided alternately at angular intervals of approximately 90 degrees in the circumferential direction. However, if it is possible to regulate the first and the second positions of the case 12 with respect to the base 11 within specified angles or angle range of the case 12 around the central axis O with respect to the base 11, a locking means in an arbitrary shape may be provided. In embodiment 1, the bottom face of the second magnet 14 abuts against the top face of the first magnet 13 in the operating state, but not only this, specified intervals may be maintained.
With the push switches 20, 30 in embodiments 2 and 3 also, a magnetic body 17 may be provided on the upward end face of the cutouts 11c′, 11d′ of the base 11A, 11B as in the case of the push switch 10.
Number | Date | Country | Kind |
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2019-148078 | Aug 2019 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/030506 | 8/7/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2021/029398 | 2/18/2021 | WO | A |
Number | Date | Country |
---|---|---|
S6149933 | Apr 1986 | JP |
H1064360 | Jun 1998 | JP |
H10340656 | Dec 1998 | JP |
2010181267 | Aug 2010 | JP |
2011238352 | Nov 2011 | JP |
2011158877 | Dec 2011 | WO |
Entry |
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International Search Report for PCT/JP2020/030506 dated Oct. 20, 2020. |
English Abstract of JP2011238352, Publication Date: Nov. 24, 2011. |
English Abstract of JPH1064360, Publication Date: Mar. 6, 1998. |
English Abstract of WO2011158877, Publication Date: Dec. 22, 2011. |
English Abstract JPH10340656, Publication Date: Dec. 22, 1998. |
Number | Date | Country | |
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20220328267 A1 | Oct 2022 | US |