Transmitter

Abstract

To provide a transmitter that can be checked for operation without removing a protective plate during inspection and that operates stably even in a tunnel environment.SOLUTION: A transmitter 1 according to the present invention includes a protection plate 7 for pushing down and operating a switch 5, and a cylindrical tube member 9 provided to enclose the protection plate 7. The protection plate 7 has an operating surface portion 11 disposed in front of the switch 5, and a guide portion 13 that guides the push-down operation in cooperation with the cylindrical tube member 9. The guide portion 13 has guide feet 19 respectively formed on a pair of opposing surfaces, guide walls 21 respectively formed on another pair of opposing surfaces, and an engagement portion 23 which is formed on one of the guide walls 21 and can be engaged with a stopper 33 that holds the protection plate 7 pressed down. The outer surfaces of the guide feet 19 and the guide walls 21 contact the inner surface of the cylindrical tube member 9 in the process of pushing down the protection plate 7 and in the state of holding it down, thereby restraining the bending of the protection plate 7.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a transmitter to be installed in a tunnel such as a highway tunnel. [Background technology]

[0002] Conventionally, a large number of transmitters such as those disclosed in Patent Documents 1 and 2 are installed at predetermined intervals in the axial direction of the tunnel on the side walls of a tunnel such as an automobile road.

[0003] As described in Patent Documents 1 and 2, the transmitters installed inside the tunnels have a protective plate made of organic glass in front of the switch to protect the switch from dust inside the tunnel and water sprayed by tunnel cleaning vehicles. When operating the transmitter, the protective plate is pushed in firmly to cause it to fall off the mounting frame, or the protective plate is crushed and the switch is pressed and operated, causing the transmitter to send out a fire signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-60580 A [Patent Document 2] JP 2016-18219 A Summary of the Invention [Problem to be solved by the invention]

[0005] Emergency equipment in tunnels, including transmitters, are inspected regularly. During inspections, the transmitter switch is actually pressed to check that it is working, but if the protective plate is pressed while pressing the switch, there is a risk that the protective plate may be damaged or lost. Therefore, in conventional inspections, the protective plate is removed before pressing the transmitter switch.

[0006] However, since there are many transmitters installed inside the tunnel, it takes time and effort to remove the parts and check their operation as described above. There is also a risk that the removed parts will be dropped and damaged or lost. Especially on expressways and other places, if something is dropped on the road, traffic control must be implemented to retrieve it, which can be a major problem.

[0007] However, unlike the above-mentioned tunnel transmitter, a transmitter installed inside a building such as a building is configured so that the protective plate does not need to be removed during inspection. A transmitter generally used for buildings has a resin protective plate and a return spring that returns the protective plate to its initial position, and the switch is pressed and operated by pushing the protective plate against the biasing force of the return spring. After that, when the force pushing the protective plate is released, the protective plate returns to its original position due to the biasing force of the return spring.

[0008] Such building transmitters may be provided with a stopper to hold the protective plate in the switch-on position. In a transmitter provided with a stopper, when the protective plate is pressed down, it engages with the stopper in the pressed state, so that the switch-on state is maintained and the fire signal continues to be transmitted even if the finger pressing down the protective plate is released. When the stopper is then released, the protective plate returns to its initial position due to the biasing force of the return spring.

[0009] The above-mentioned building transmitter does not require the removal of the protective plate when checking the operation during inspection, so the adoption of this configuration is thought to solve the problems of the tunnel transmitter described above. However, since building transmitters are designed for use inside buildings, the following problems arise when they are used inside a tunnel.

[0010] First, in tunnels, pressure may be applied to the protective plate due to water spraying from cleaning vehicles, etc., so it is necessary to set the biasing force of the return spring strong so that this does not turn on the transmitter. However, if the biasing force of the return spring is strong, the protective plate is likely to tilt when pressed with a finger due to the reaction force of the return spring. If the protective plate tilts, it may become difficult for the locking portion provided on the protective plate to lock with the stopper. In addition, even when the protective plate is engaged with the stopper, the part away from the engaging part is pushed up by the reaction force of the return spring, so the protective plate is prone to tilting. If the protective plate is tilted, it will not be possible to push the switch down to the retaining position, and there is a risk that the switch will not be able to be maintained in the on state.

[0011] Furthermore, in buildings, a mechanism for releasing the stopper is provided on the inside of the door on the front of the transmitter, but since transmitters installed in tunnels need to be waterproof, it is preferable not to provide a door on the front of the transmitter. Also, since building transmitters are not designed to be used in dusty environments such as tunnels, there is a risk that operation will become unstable if dust gets inside the transmitter.

[0012] The present invention has been made to solve the above-mentioned problems, and aims to provide a transmitter whose operation can be confirmed during inspection without removing the protective plate, and which operates stably even in the environment inside a tunnel. [Means for solving the problem]

[0013] (1) A transmitter according to the present invention includes a protective plate that is operated by depressing a switch, and a cylindrical member that is provided to surround the protective plate, the protective plate has an operation surface portion disposed on a front surface of the switch, and a guide portion provided on an outer periphery of the operation surface portion, extending in the direction of the pressing operation, and cooperating with the cylindrical member to guide the pressing operation, the guide portion has guide legs formed on a pair of opposing surfaces, guide walls formed on the other pair of opposing surfaces, and a locking portion formed on one of the guide walls and capable of locking with a stopper that holds the protective plate in a pressed-down state; In the process of pushing down the protective plate and in the state where it is pushed down and held down, the outer surfaces of the guide legs and the guide walls come into contact with the inner surface of the tubular member, thereby suppressing deflection of the protective plate.

[0014] (2) Furthermore, in the above-mentioned (1), a linear protrusion extending in the direction of the downward operation of the protective plate is provided on the outer surfaces of the guide foot and the guide wall, and the linear protrusion contacts the inner surface of the tubular member. Effect of the Invention

[0015] The transmitter of the present invention operates stably in the tunnel environment and can be inspected without removing the protective plate, significantly reducing the effort and time required for inspection. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view of a transmitter according to an embodiment. [Diagram 2] FIG. 2 is a front view of the transmitter of FIG. [Diagram 3] FIG. 2 is a bottom view of the transmitter of FIG. [Figure 4] FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. [Diagram 5] 2 is a perspective view showing the protection plate of FIG. 1 alone. FIG. [Figure 6] 2 is a perspective view showing the tubular member of FIG. 1 alone. FIG. [Figure 7] FIG. 2 is a diagram showing an example of installation of the transmitter of FIG. 1. [Figure 8] FIG. 11 is a cross-sectional view showing a state in which the protective plate is being pressed down (without tilting the protective plate). [Figure 9]13 is a cross-sectional view showing a state in which the locking portion of the protective plate is locked with the stopper (the protective plate is not inclined). FIG. [Figure 10] FIG. 13 is a perspective view showing a state in which the protective plate is pressed down. [Figure 11] FIG. 11 is a cross-sectional view showing a state in which the protective plate is being pressed down (the protective plate is inclined). [Figure 12] 13 is a cross-sectional view showing a state in which the locking portion of the protective plate is locked to the stopper (with the protective plate inclined). FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] A transmitter 1 according to one embodiment of the present invention is installed in a tunnel such as a highway, and as shown in Figures 1 to 4, comprises a signal transmitting unit 3 for transmitting a fire signal, a protective plate 7 that operates by pressing down a switch 5 (see Figure 4) of the signal transmitting unit 3, and a tubular member 9 arranged to surround the protective plate 7. Each component of the transmitter 1 will be described in detail below.

[0018] <Signal sending section> The signal transmitting unit 3 is a portion including a circuit for transmitting a fire signal, and has a switch 5 provided so as to be capable of appearing and disappearing, as shown in FIG. The switch 5 is normally biased by a biasing means (not shown) on the protective plate 7 side (front side) so that it is in the out state, and is in the down state when pressed with a specified force. When the switch 5 is in the down state, it transmits a fire signal. Hereinafter, the state in which the fire signal is transmitted is referred to as the "switch on state." It is more preferable to fit a packing or the like to the switch 5 to prevent water from entering the inside of the switch 5.

[0019] <Protection plate> The protective plate 7 is a member that protects the switch 5 from water sprayed by a tunnel cleaning vehicle and dust in the air, and is used to press down the switch 5, and is made of resin or the like. As shown in Fig. 5, the protective plate 7 has a circular operation surface portion 11 and a guide portion 13 that is provided on the outer periphery of the operation surface portion 11 and extends in the direction in which the protective plate 7 is pressed down. The protective plate 7 is constantly biased in an upward direction by a protective plate coil spring 15 provided on the back side of the operation surface portion 11 (see FIG. 4). The biasing force of the protective plate coil spring 15 is set to be stronger than the pressure received from water spray from a tunnel cleaning vehicle so that the protective plate 7 is not pushed down by the water spray from the tunnel cleaning vehicle.

[0020] The operation panel 11 is disposed on the front side of the switch 5 as shown in Fig. 4, and is the portion that an operator presses with his / her finger. When the operation panel 11 is pressed with a finger, a cylindrical switch abutment portion 17 provided on the rear side of the operation panel 11 presses the switch 5, depressing the switch 5. When the switch 5 is depressed (see Fig. 9), a fire signal is transmitted from the signal transmission portion 3.

[0021] 5, the guide portion 13 is composed of four guide legs 19 and a pair of guide walls 21. When the operation surface portion 11 is pressed against the biasing force of the protective plate coil spring 15, the guide portion 13 cooperates with the tubular member 9 to guide the pressing down operation of the protective plate 7. Furthermore, as will be described in more detail later, while the protective plate 7 is being pressed down or while the pressed-down state of the protective plate 7 is being maintained, a force acts on the protective plate 7 to deflect it; however, in addition to the guide feet 19, the outer surfaces of the guide walls 21 come into contact with the inner surface of the tubular member 9 all around the protective plate 7, thereby suppressing the deflection of the protective plate 7.

[0022] In the example of Fig. 5, two guide legs 19 are formed on each of a pair of opposing surfaces. Also, guide walls 21 are formed on each of the other pair of opposing surfaces. Note that the number of guide legs 19 is not limited to the example of Fig. 5, and one guide leg 19 may be provided on each of a pair of opposing surfaces, or three or more guide legs 19 may be provided on each of a pair of opposing surfaces.

[0023] As shown in Fig. 4, one side of the guide wall 21 is formed with a locking portion 23 that can be locked with an inclined protruding piece 35 of a stopper 33 described later. When the protective plate 7 is pressed down, as shown in Fig. 9, the locking portion 23 of the protective plate 7 is adapted to be locked with the inclined protruding piece 35 of the stopper 33, thereby maintaining the pressed-down state of the protective plate 7.

[0024] As mentioned above, since the transmitter 1 of this embodiment is intended to be installed inside a tunnel, the biasing force of the coil spring 15 for the protective plate needs to be set strong so that the protective plate 7 is not pressed down by water sprayed by the tunnel cleaning vehicle. If the biasing force of the protective plate coil spring 15 is made stronger, the reaction force of the protective plate coil spring 15 when the protective plate 7 is pressed down is large, and the protective plate 7 is more likely to tilt. If this tilt becomes large, the locking portion 23 may not lock with the stopper 33 even if the protective plate 7 is pressed down. Furthermore, in the cantilever state where the locking portion 23 is locked to the stopper 33, the protective plate 7 is easily tilted because it is strongly pushed up by the protective plate coil spring 15. If this tilt becomes too great, the switch 5 cannot be pushed down to the position where the fire signal is transmitted, and there is a risk that the switch-on state will be released.

[0025] In this embodiment, in order to solve the above problems, guide walls 21 are provided on the surface of guide portion 13 that engages with stopper 33 and on the opposing surface. By providing plate-shaped guide walls 21 at these positions, the above-mentioned tilt of protective plate 7 can be suppressed. The function of the guide wall 21 in preventing the protective plate 7 from tilting will be described in more detail in the operation description given later.

[0026] As shown in FIG. 5, linear protrusions 25 are provided on the outer surfaces of the guide feet 19 and the guide walls 21, extending in the direction of the downward operation of the protective plate 7, and the linear protrusions 25 come into contact with the inner surface of the tubular member 9 when the protective plate 7 is inserted into the tubular member 9. By providing the linear protrusions 25, when the protective plate 7 slides inside the cylindrical member 9, only the linear protrusions 25 can be brought into contact with the inner surface of the cylindrical member 9, thereby reducing friction between the two. This reduces the resistance when the protective plate 7 is pressed in, and also reduces wear between the protective plate 7 and the cylindrical member 9. In the present invention, it is not essential to provide the linear protrusions 25 on the outer surfaces of the guide legs 19 and the guide walls 21 .

[0027] Furthermore, by making the linear protrusions 25 the contact points between the protective plate 7 and the tubular member 9 as described above, it becomes easy to adjust the clearance between the protective plate 7 and the tubular member 9. It is desirable to make the clearance between the protective plate 7 and the tubular member 9 as small as possible to prevent water or dust from entering the interior, but since this clearance can be adjusted by the protruding height of the linear protrusions 25, there is no need to adjust the shape of the entire guide part 13, making it easy to modify the mold shape.

[0028] <Cylinder Part> The cylindrical member 9 is made of a resin cylindrical body, and the inner shape thereof conforms to the outer shape of the guide portion 13 of the protective plate 7, as shown in Fig. 6. One side wall of the cylindrical member 9 is formed with a notch 9a into which the locking portion 23 of the guide wall 21 described above is inserted.

[0029] As described above, the cylindrical member 9 has an inner surface shape that conforms to the guide portion 13 of the protection plate 7, and cooperates with the guide portion 13 to guide the pressing down operation of the protection plate 7.

[0030] 6, a linear protrusion 27 is provided on the outer surface of the tubular member 9, extending in the direction of the pressing operation of the protective plate 7. By providing the linear protrusion 27, even if a force that deforms the tubular member 9 is generated when the protective plate 7 is pressed down, the linear protrusion 27 comes into contact with the inner surface of the housing member 29 to suppress the deformation of the tubular member 9, thereby preventing damage to the tubular member 9. In addition, by providing the linear protrusion 27, the clearance between the tubular member 9 and the housing member 29 can be easily adjusted, similarly to the linear protrusion 25 described above. Before the tubular member 9 is deformed (when no force is acting on the tubular member 9), the linear protrusions 27 do not necessarily need to be in contact with the inner surface of the accommodating member 29, but it is preferable for them to be in contact because this makes it easier to adjust the above-mentioned clearance.

[0031] The protective plate 7 and the tubular member 9 described above are housed in a housing member 29 that is a bottomed frame (see FIG. 1). A pair of plate-shaped mounting members 31 are provided on the edge of the housing member 29, and as shown in FIG. 7, the mounting members 31 are fixed to the back of a door 41 of a fire hydrant device 39 installed, for example, in a tunnel to install the transmitter 1. In the example of FIG. 7, as shown in the enlarged view in the figure, the mounting members 31 are fixed with nuts to four studs 43 provided on the back of the door 41. When the door 41 is closed, only the operation surface portion 11 of the protective plate 7 is exposed to the outside through an opening formed in the door 41.

[0032] 4, a rotary stopper 33 is provided on one side of the housing member 29 so as to face the locking portion 23 of the guide wall 21. The stopper 33 has an inclined protruding piece 35 that gradually protrudes toward the locking portion 23 as the protective plate 7 is pressed down, and a release lever 37 for releasing the switch-on state.

[0033] A notch 29a into which the inclined protrusion 35 of the stopper 33 is inserted is formed in one side wall of the accommodating member 29. The stopper 33 is biased by a stopper coil spring (not shown) so that the inclined protrusion 35 approaches the guide wall 21. Under normal circumstances, the lower end of the inclined protrusion 35 protrudes below the engaging portion 23 toward the guide wall 21 beyond the engaging portion 23 (see FIG. 4).

[0034] Although the details will be explained later in the operation explanation, when protective plate 7 is pressed down, locking portion 23 climbs over inclined protrusion 35 and locks with inclined protrusion 35 (see FIG. 9). When locking portion 23 and inclined protrusion 35 are locked together, if release lever 37 of stopper 33 is pulled as shown by the arrow in FIG. 3, the locked state between locking portion 23 and inclined protrusion 35 can be released.

[0035] <Operation description> The operation of the transmitter 1 according to this embodiment configured as above will be described with reference to FIG. 4 and FIGS. 8 to 12. When the operation surface portion 11 of the protective plate 7 of the transmitter 1 shown in Fig. 4 is pressed with a finger, the guide portion 13 is guided by the cylindrical member 9, and the protective plate 7 moves downward while maintaining the posture before pressing. When the protective plate 7 moves downward, the locking portion 23 comes into contact with the inclined protrusion portion 35 of the stopper 33, and presses the inclined protrusion portion 35 outward.

[0036] The stopper 33 pressed by the engaging portion 23 rotates in the clockwise direction in the figure against the biasing force of the stopper coil spring, as shown in Fig. 8. When the protective plate 7 is pressed down to a certain extent, the switch 5 is depressed and a fire signal is sent.

[0037] When the protective plate 7 is pushed all the way in, the locking portion 23 climbs over the inclined protrusion 35, and the stopper 33 returns to its initial position due to the biasing force of the stopper coil spring. As a result, as shown in Fig. 9, the locking portion 23 locks onto the lower end of the inclined protrusion 35 of the stopper 33, so that even if the finger is released from the protective plate 7 in this state, the pressed-down state of the protective plate 7, i.e., the switched-on state, is maintained. At this time, the fire signal continues to be transmitted. For reference, Fig. 10 shows a perspective view of the transmitter 1 in the state shown in Fig. 9.

[0038] To release the protective plate 7 from its depressed state, the door 41 of the fire hydrant device 39 is opened as shown in Fig. 7, and the release lever 37 of the stopper 33 (see the enlarged view of Fig. 7) is pulled in the direction of the arrow shown in Fig. 3. This releases the engagement between the inclined protruding piece 35 and the engagement part 23, and the protective plate 7 returns to the state before it was depressed as shown in Fig. 4 due to the biasing force of the protective plate coil spring 15. This also releases the depressed state of the switch 5, and stops the transmission of the fire signal.

[0039] As mentioned above, the transmitter 1 of this embodiment is intended to be installed inside a tunnel, so the biasing force of the coil spring 15 for the protective plate needs to be set strong so that the protective plate 7 is not pressed down by water sprayed by the tunnel cleaning vehicle. In Figures 8 and 9, it has been explained that while protective plate 7 is being pressed down and while the pressed down state is maintained, protective plate 7 maintains the posture before being pressed down. However, if the biasing force of protective plate coil spring 15 is increased, the reaction force when protective plate 7 is pressed down also increases, and if the position where protective plate 7 is pressed is shifted from the center, a force is applied that tilts the entire protective plate 7.

[0040] When protective plate 7 tilts, guide portion 13 comes into contact with tubular member 9, and a force acts to bend guide portion 13, which is made of resin. If guide portion 13 bends more, protective plate 7 also tilts more, which is undesirable as it makes the operation of transmitter 1 unstable. Therefore, in the transmitter 1 of this embodiment, a guide wall 21 is provided on the guide portion 13 of the protective plate 7 as a measure to suppress the bending of the guide portion 13 and reduce the tilt of the protective plate 7, which will be described in detail using Figures 11 and 12.

[0041] FIG. 11 shows a state in which the side of the operation panel 11 opposite to the side where the stopper 33 is provided, that is, the position farthest from the stopper 33, is being pressed with a finger. When a finger is pressed at a position away from the stopper 33, the pressed side sinks deeply, but the opposite side, i.e., the stopper 33 side, is pushed up by the protective plate coil spring 15, and a force is applied that tilts the protective plate 7 downward to the right in the figure.

[0042] When a force that tilts protective plate 7 as described above occurs, a large load is generated on the surface of guide portion 13 that engages with stopper 33 and the surface facing this. To resist such a force, in this embodiment, guide walls 21 are provided at these positions. By providing plate-shaped guide walls 21 at the portions where the load is large, linear protrusions 25 of guide walls 21 come into contact with the inner surface of tubular member 9, suppressing the deflection of protective plate 7, and even when a position away from stopper 33 is pressed with a finger, the tilt of protective plate 7 can be kept small as shown in FIG. 11.

[0043] If the guide wall 21 provided on the surface that engages with the stopper 33 and the surface facing this were replaced with a guide foot 19, when a force is applied to the protective plate 7 to tilt it downward to the right as in Figure 11, the guide foot 19 will come into contact with the tubular member 9 and resist this force. However, since the guide foot 19 has a lower rigidity than the guide wall 21 and the area of ​​contact with the tubular member 9 is also smaller, it is thought that the deflection will be even greater than in Figure 11, causing the protective plate 7 to tilt more.

[0044] 11, even if the protective plate 7 is pressed down, the engaging portion 23 may not be able to overcome the inclined protruding piece portion 35 of the stopper 33, and the protective plate 7 may not be engaged with the stopper 33. In that case, when the finger is released from the protective plate 7, the protective plate 7 returns to the position before it was pressed down, and the fire signal cannot be continued to be transmitted. In addition, since the guide legs 19 have a smaller strength than the guide walls 21, there is a risk that the guide legs 19 may break if the above-mentioned bending becomes large.

[0045] However, when pressing down the protective plate 7, pressing the center of the operation surface portion 11 or pressing so as to touch the entire operation surface portion 11 makes it easier to maintain the posture before pressing down, and the above-mentioned problems are less likely to occur. Therefore, it is more preferable to mark the operation surface portion 11 with a mark or the like that guides the position to be pressed with the finger to the center of the operation surface portion 11.

[0046] Even when the protective plate 7 is held in the pressed-down state, the protective plate 7 is held in a cantilevered state by the stopper 33, so that a force that tilts the entire protective plate 7 acts due to the reaction force of the protective plate coil spring 15. The above-mentioned guide wall 21 also suppresses such tilting, and will be described with reference to FIG.

[0047] 12 is a diagram showing a state in which protective plate 7 is engaged with stopper 33, but unlike Fig. 9, a portion of protective plate 7 opposite to the side engaged with stopper 33 is pushed up by protective plate coil spring 15, and protective plate 7 is slightly tilted downward to the left in the figure. Thus, when protective plate 7 and stopper 33 are engaged with each other, a force acts on protective plate 7 to tilt it downward to the left in the figure as shown in Fig. 12.

[0048] The above-mentioned guide wall 21 resists the above-mentioned tilt, so that even when the protection plate 7 is engaged with the stopper 33, the tilt of the protection plate 7 can be kept small as shown in FIG.

[0049] If the guide wall 21 provided on the surface that engages with the stopper 33 and the surface opposite thereto were replaced with a guide foot 19, it is conceivable that the protective plate 7 would be tilted even more than in FIG. 12, as explained in FIG. 11. If the protective plate 7 is tilted further downward and to the left than in Figure 12, even if the protective plate 7 is engaged with the stopper 33, the switch 5 may not be held in the on position and the fire signal may not be able to continue to be transmitted.

[0050] As described above, the surface of the guide portion 13 that engages with the stopper 33 and the surface opposite thereto are the areas that are most heavily loaded when a force is applied that causes a tilt as shown in Figures 11 and 12. Therefore, by providing a guide wall 21 with high strength at these areas, it is possible to suppress the deflection of the protective plate 7 and reduce the tilt. Moreover, by suppressing the bending of the protective plate 7, damage to the protective plate 7 can also be prevented.

[0051] As described above, in this embodiment, the switch 5 is depressed by pressing the resin protective plate 7, and further, this protective plate 7 returns to the position before pressing by the protective plate coil spring 15, so there is no need to remove the protective plate 7 when checking the operation during inspection. Therefore, even if the switch is installed in a tunnel on a highway or the like, there is no risk of traffic restrictions due to parts falling, and the labor required for inspection can be significantly reduced.

[0052] In addition, in this embodiment, the provision of the guide legs 19 and the guide walls 21 can reduce the deflection of the protective plate 7. Therefore, the biasing force of the protective plate coil spring 15 can be set to be strong, and the protective plate 7 will not be pressed down by water sprayed by a tunnel cleaning vehicle, which is suitable for the environment inside a tunnel.

[0053] In addition, because the stopper 33 in this embodiment is of a rotating type, even if dust floating in the space inside the tunnel gets inside the transmitter 1, the operation of the stopper 33 is unlikely to be affected. Therefore, the stopper 33 operates stably even in an environment with a lot of floating dust, making it suitable for the environment inside a tunnel.

[0054] Furthermore, in this embodiment, plate-shaped guide walls 21 are provided on the surface on the stopper 33 side and the opposing surface far from the stopper 33, so that guide walls 21 come into surface contact with tubular member 9 and protective plate 7 is unlikely to tilt. Specifically, even when a position far from stopper 33 is pressed with a finger, the side closer to stopper 33 is unlikely to tilt so as to float up, and further, even when protective plate 7 is engaged with stopper 33, the side far from stopper 33 is unlikely to tilt so as to float up. Therefore, engaging portion 23 of protective plate 7 is reliably engaged with stopper 33, and while the engaged state is maintained, the switch-on state can be reliably maintained, so that the operation of transmitter 1 is stable.

[0055] In the above-described embodiment, the protection plate 7 is configured to be held down, but if it is not necessary to continue transmitting the fire signal, the stopper 33 may be removed. By removing the stopper 33 from the transmitter 1 of this embodiment, it is also possible to configure the device to transmit the fire signal only when the protection plate 7 is pressed with a finger. [Explanation of symbols]

[0056] 1 Transmitter 3. Signal Generator 5. Switch 7 Protective plate 9. Cylinder Parts 9a Notch 11 Operation surface section 13 Guide section 15 Coil spring for protective plate 17 Switch contact part 19 Guide foot 21 Guide Wall 23 Locking part 25 Linear convex part 27 Linear convex part 29 Storage material 29a Notch 31 Mounting material 33 Stopper 35 Slanted protruding piece 37 Release lever 39 Fire hydrant equipment 41 Door 43 Stud

Claims

1. A transmitter including a protective plate that operates a switch by pressing down, and a cylindrical member that is provided to surround the protective plate, the protective plate has an operation surface portion disposed on a front surface of the switch, and a guide portion provided on an outer periphery of the operation surface portion, extending in the direction of the pressing operation, and cooperating with the cylindrical member to guide the pressing operation, the guide portion has guide legs formed on a pair of opposing surfaces, guide walls formed on the other pair of opposing surfaces, and a locking portion formed on one of the guide walls and capable of locking with a stopper that holds the protective plate in a pressed-down state; A transmitter characterized in that, during the process of pushing down the protective plate and when it is held down, the outer surfaces of the guide legs and the guide walls come into contact with the inner surface of the tubular member, thereby suppressing deflection of the protective plate.

2. 2. The transmitter according to claim 1, wherein the outer surfaces of the guide legs and the guide walls are provided with linear protrusions extending in the direction of the downward operation of the protective plate, and the linear protrusions contact the inner surface of the cylindrical member.

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