JPS6244446Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a manual return type safety switch that, once activated by an external command, can be reset only by manual operation.

For example, in the combustion safety control system installed to safely and reliably control the combustion operation sequence in various boilers, water heaters, etc., when an ignition failure or an abnormal condition during combustion is detected, the system always switches to the safe side. It is necessary to provide a safety switch for operation. In order to ensure safety, this safety switch must be of a manual reset type that does not automatically reset once activated, but can only be reset by manual operation. is desired.

Furthermore, when this manual return means is accidentally activated for purposes other than manual return, it is necessary that the contact mode of the safety switch operate on the safe side.

The purpose of this invention is to provide a manual return type safety switch with a simple structure to achieve this purpose.

Next, an embodiment of this invention will be described with reference to the drawings. A cover 2 is attached to the base made of an insulating material, which is indicated by the reference numeral 1 in FIGS. 1 and 2.
are attached to form the casing. This cover 2 includes a main body 21 having a rectangular tube shape in this example,
The main body 21 has a top wall that closes one end of the main body 21. This top wall consists of a flat portion 22 and a thinner corrugated portion 23 , and an actuating member 3 is placed in the center of the corrugated portion 23 so as to be located inside the main body 21 .
An operating member 4 having a cylindrical shape with a closed upper end is formed so as to protrude from the operating member 3 to the outside of the main body 21 . All of these elements are constructed by integrally molding transparent synthetic resin such as polyethylene, but slits 24 are formed on both sides of the corrugated portion 23, and the actuating member 3 has a portion of the slits 24 formed on both sides of the corrugated portion 23. Since the actuating member 3 and the operating member 4 are separated from the corrugated portion 23 by the slit 25, the actuating member 3 and the operating member 4 cannot move within a predetermined range in the axial direction of the main body 21 due to the elastic deformation of the corrugated portion 23. Can be done. In the embodiment, the elastic member is formed by the corrugated portion 23, but the structure is such that an ordinary leaf spring is used to return the operating member 3 and the operating member 4, which are provided separately from the cover 2, to their home positions. It's okay to be hot.

Further, a movable member 5 is housed within the casing so as to be movable within a predetermined range in the same direction as the operating member 2. This moving member 5 is located at the first position closest to the base 1 (the position shown in FIG. 1).
and a second position remote from the base 1, and is biased by the action of a spring 6 to move from the first position to the second position. . and the first position and the second position
base 1 by moving to and from the position of
A plurality of trippers 5a, 5b, 5c for closing or opening a plurality of switch elements 7, 8, 9 each consisting of a pair of contact blades supported by a
and an identification portion 5d that protrudes into the center hole of the operating member 4. In this example, when the moving member 5 is in the first position, the switch elements 7, 8 are closed and the switch element 9 is open. In addition, switch elements 7 and 8
is opened by the actuating member 3 when the actuating member 3 is lowered together with the operating member 4. This ensures that if the actuating member 4 is accidentally pressed other than for manual return, the switch elements 7, 8 open and operate on the safe side.
As shown in FIG. 2, the switch element 9 is not affected by the lowering of the actuating member 3 and remains open as long as the movable member 5 is in the first position. It is configured to respond to requests.

FIG. 3 shows the support structure of the moving member 5 in detail. The moving member 5 has a cylindrical shape with an open lower end, and a cylindrical guide portion 1a integrally formed with the base 1 projects into the center hole thereof. This allows the moving member 5 to move smoothly only in its axial direction.

Furthermore, a holding mechanism 10 is provided within the casing for holding the movable member 5 in the first position and releasing the movable member 5 in response to an external command to move it to the second position. . This holding mechanism 10 includes a coil 12 wound around a bobbin 11.
and a core 13 passing through the center hole of the bobbin 11.
An armature 14 supported by this core 13,
It is composed of a leaf spring 15 for returning the armature 14. This armature 14
extends downward substantially parallel to the axis of the coil 12, and has an engagement hole 14a formed at its tip end to engage with an engagement protrusion 5e provided on the moving member 5. One end of the core 13 is bent at a substantially right angle below the bobbin 11 and faces the free end of the armature 14 with a predetermined gap formed therein. In this state, the moving member 5 is held in the first position by engagement with the armature 14.

Now, if a predetermined current is supplied to the coil 12 from the outside, this current will initiate a magnetic attraction between the core 13 and the armature 14, which face each other forming a gap. Therefore, the armature 14 rotates counterclockwise in FIG. 2 about one end thereof. As a result, the engagement between the armature 14 and the engagement protrusion 5e is released, and the moving member 5 is moved from the first position to the second position by the action of the spring 6. As a result, the trippers 5a, 5b, and 5c rise, so that the switch elements 7 and 8 are opened, and the switch element 9 is opened to enter a safe operation.

To return the moving member 5, the current to the coil 12 is interrupted and the armature 14 has returned to its original position by the action of the leaf spring 15, and then the operating member 4 is manually pushed down, and the operating member 3 is This is done by moving the moving member 5 to the first position. When the moving member 5 reaches the first position,
The engagement protrusion 5c is connected to the engagement hole 14a of the armature 14.
Even when the operating member 4 is released, the moving member 5 is held in the first position. That is, the safety switch does not automatically return to its original state after it has been activated, but can only be returned to its original state by manual operation, thereby ensuring safety.

When the movable member 5 moves in this manner, the identification portion 5d also moves within the visible center hole of the operating member 4. Therefore, if the identification portion 5d is colored in an easily noticeable manner, the position of the moving member 5, that is, the operating state of the switch can be easily confirmed from the outside based on the position of the identification portion 5d.

FIG. 3 shows an example in which the holding mechanism 10 is a thermal timer type having a U-shaped bimetal 16 and an inner cylindrical heater 17 arranged inside the curved part of the bimetal 16. It shows.
When no current is supplied to the heater 17,
Engaging portion 16a formed at the free end of bimetal 16
holds the movable member 5 at the first position by engaging with the engagement protrusion 5e. However, when the heater 15 is energized, the bimetal 16 is heated and the engagement portion 1 is deformed due to the temperature rise.
6a is gradually displaced, and after a certain period of time, the engagement protrusion 5e
At this time, the moving member 5 moves from the first position to the second position.

Note that the holding mechanism 10 is not limited to the one described above, and various forms used in this field can be applied.

As described above, according to this invention, a plurality of trippers are formed on a single moving member, and by moving the moving member, the switching elements corresponding to each tripper are simultaneously opened and closed. Furthermore, the movable member has a cylindrical shape and is configured to move while being engaged with a guide portion that also has a cylindrical shape, so that the movable member can only move in its axial direction. Furthermore, the spring that biases the moving member from the first position to the second position is housed in the moving member and the guide portion, each of which has a cylindrical shape. There is no problem, and insulation can be ensured. Furthermore, the safety switch in this invention cannot be reset except manually, and even if the operating member is lowered due to a malfunction other than reset,
Since the actuating member is configured to always operate in the safe mode, an extremely high level of safety is achieved.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a manual return type safety switch according to an embodiment of this invention, and Fig. 2 is a vertical sectional view taken from A--A in Fig. 1.
3 is a longitudinal sectional view of a portion thereof, and FIG. 4 is a sectional view similar to FIG. 2 showing a safety switch according to another embodiment. DESCRIPTION OF SYMBOLS 1... Base, 1a... Guide part, 2... Cover, 21... Main body, 22... Flat part, 23...
Waveform portion, 24, 25...slit, 3... operating member, 4... operating member, 5... moving member, 5a~
5c... Tripper, 5d... Identification part, 5e... Engaging protrusion, 7-9... Switch element, 10... Holding mechanism, 11... Bobbin, 12... Coil, 13...
... Core, 14 ... Armature, 14a ... Engagement hole, 16 ... Bimetal, 16a ... Engagement part, 1
7... Heater.

Claims (1)

[Claims for Utility Model Registration] (1) A moving member 5 urged by a spring 6 from a first position to a second position, and trippers 5a, 5b, 5c provided on this moving member.
and switch elements 7, 8, 9 provided on the base 1 and opened or closed by the movement of the trippers 5a, 5b, 5c as the moving member 5 moves.
an operating member 4 for moving the movable member 5 from the second position to the first position; and an operating member 4 formed integrally with this operating member, so that when the operating member is moved to the first position, the switch The operating member 3 opens and closes the element in a safe mode, and the moving member 5 that has been moved to the first position is held at that position, and the moving member 5 is operated in response to an external command.
A manual return type safety switch consisting of a holding mechanism consisting of an electromagnetic coil that releases. (2) The distal end of the movable member 5 is arranged so as to be inserted into the hollow portion of the operating member 4, and the operating member is made of a transparent material, and the inserted portion of the movable member 5 has a colored portion. A manual return type safety switch according to claim 1 of the utility model registration claim, which is provided with: (3) The moving member 5 has a cylindrical shape with an open lower end, and the cylindrical guide portion 1a integrally formed with the base 1 is inserted into the center hole of the moving member 5. Scope of registration claims No. 1
Manual return type safety switch as described in .