Transmitter

Abstract

To provide a transmitter comprising a push-button switch which can be surely turned on by stable parallel movement even if a protective panel is inclined in a case where it is pressed, and is not likely to be damaged even under operation with a strong force.SOLUTION: A transmitter comprises: a main body part incorporating a push-button switch which is turned into an ON state by a push-in operation from the outside; and a protective panel including a planar pressing part and disposed so as to be positioned outside of the push-button switch. The push-button switch is turned on by pushing in the protective panel. The protective panel includes a guided part and in the main body part, a guide member is provided for guiding the guided part movably in a push-in direction of the protective panel. In the guide member, a plurality of contact pieces capable of being in contact with an outer surface of the guided part is provided, and the plurality of contact pieces is pressed to the outer surface of the guided part toward a center of the protective panel by an elastic force.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a technique that is effective when used in a fire alarm transmitter that is provided on, for example, a wall of a building and that issues an alarm when operated in the event of a fire. [Background technology]

[0002] A fire alarm system is installed inside a building to notify people of the occurrence of a fire. The fire alarm system is composed of a fire detector, a manual fire alarm transmitter with a push button switch, a receiver, a fire alarm bell, a signal light, etc., and the fire alarm transmitter is installed at an appropriate height on the wall of a building's corridor, etc. When a fire occurs, the person who discovers it presses the push button of the fire alarm transmitter hard to turn on the internal switch, which transmits a signal notifying the occurrence of a fire to the receiver and also emits an alarm sound from a bell installed near the transmitter, thereby notifying people in the vicinity of the occurrence of a fire.

[0003] Conventional fire alarm transmitters generally have a disk-shaped front panel on the front of the transmitter body that covers the exposed parts of the room, and the transmitter body has a push button switch inside. Conventional fire alarm transmitters include those with a tilting configuration in which a push button B located in the center of the front of the transmitter tilts around a fulcrum F located at one end (the bottom end in the figure) to turn on an internal switch SW, as shown in Figure 8, and those with a sliding configuration in which a push button (pressure protection plate) moves in parallel. Patent Documents 1 and 2, for example, describe inventions relating to fire alarm transmitters having a slide-type push button. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 04-85699 [Patent Document 2] JP 2014-153993 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with a tilting push button, when pressed with a finger, the front of the push button tilts, causing the finger to slip and the fingertip to get caught in the gap of the opening in the front panel, causing discomfort. On the other hand, in the transmitter of Patent Document 1 which has a sliding push button, four guide pieces are provided on the pressable protective plate which protrude backward, and a guide section is provided on the main body side. This structure means that the guide member is easily deformed, making the protective plate less stable when pressed with a finger and less durable. In addition, if the diameter of the push button is large, a strong force may act at a position offset from the center when the push button is pressed, which may cause the guide pieces to be damaged.

[0006] In addition, in the transmitter of Patent Document 2, when a pressing force acts on a position shifted from the center of the sliding body S as shown in Fig. 5(A), the sliding body S becomes inclined as shown in Fig. 5(B), and gets stuck (so-called "seizing") at the points shown by the circles K1 and K2, preventing it from moving all the way to the back, and there is a risk that the internal switch will not be turned on. Therefore, it is conceivable to realize a structure that moves horizontally and reliably turns on the internal switch by bringing the gap between the sliding body S and the guide member 16d that guides the sliding body close to zero, but to realize such a structure, it is necessary to increase the machining precision and control the dimensions of the parts to the utmost limit, which poses a problem of increased costs.

[0007] To provide a transmitter that has been made with attention to the above-mentioned problems, and that can reliably turn on the switch by stably moving the protective plate in parallel even if the protective plate is tilted when pressed, and that is not likely to be damaged even if the protective plate is pressed with a strong force. Another object of the present invention is to provide a transmitter that can stably move in parallel to turn on the switch reliably even if the protective plate is tilted when pressed in, without having to control the dimensions of the parts to the utmost limit. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides A transmitter comprising: a main body incorporating a push button switch that is turned on by pressing from the outside; and a protective plate having a planar pressing portion and disposed outside the push button switch, the push button switch being turned on when the protective plate is pressed; The protective plate includes a guided portion, a guide member that guides the guided portion in a push-in direction of the protection plate, the guide member being provided on the main body portion; The guide member is provided with a plurality of contact pieces capable of contacting the outer surface of the guided portion, surrounding the guided portion, and the plurality of contact pieces are configured so as to be pressed against the outer surface of the guided portion toward the center of the protective plate by elastic force.

[0009] According to the above configuration, since the multiple contact pieces are pressed against the outer surface of the guided portion toward the center of the protective plate by elastic force, even if the protective plate tilts when it is pushed in, it can be moved in parallel in a stable position to reliably turn on the switch. In addition, since the protective plate does not have a fragile portion such as a guide piece protruding backward, the risk of damage can be reduced even if the protective plate is pushed in with a strong force. Furthermore, even if there is a gap between the guided portion of the protective plate and the guide member on the main body side, since the multiple contact pieces are pressed against the outer surface of the guided portion toward the center of the protective plate by elastic force, even if the protective plate tilts when it is pushed in, it can be moved in parallel in a stable manner to reliably turn on the switch, without having to control the dimensions of the parts to the utmost limit.

[0010] Preferably, the contact piece is an elastically deformable leaf spring formed by providing a pair of slits in the guide member. According to this configuration, even if the protection plate is tilted when it is pushed in, it can be moved parallel in a stable position without increasing the number of parts.

[0011] Alternatively, the contact piece may comprise a plate member arranged to face the outer surface of the guided portion, and be configured to be pressed against the outer surface of the guided portion toward the center of the protective plate by the elastic force of a spring member arranged between the plate member and the outer surface of the guided portion.

[0012] Also, preferably, a spring member is provided on the rear portion of the protective plate to bias the protective plate in a direction opposite to the pushing direction, The guided portion has a claw portion at an end portion in the pushing direction of the protective plate for preventing the protective plate from jumping out, the claw portion being engageable with an edge portion of the guide member. With this configuration, a spring member that biases the protective plate in the direction opposite to the pushing direction can provide a restoring force that returns the protective plate to its original position, and even if such a spring member is provided, the protective plate can be prevented from popping out due to the restoring force of the spring member.

[0013] Also, preferably, the device further comprises a front panel portion having an opening at the center and disposed outside the main body portion, An outer protective plate is arranged in the opening of the front panel portion, and has a planar pressing portion and a rod portion provided on the back surface of the pressing portion, so that the end of the rod portion abuts against the pressing portion of the protective plate. With this configuration, the transmitter can be provided with a front panel portion that covers the front side of the main body portion, thereby improving the design of the transmitter. Even if a front panel portion is provided, the switch can be turned on by moving the protective plate (inner protective plate) inside the main body portion by pushing in the outer protective plate. Even if the inner protective plate tilts when the outer protective plate is pushed in, it can be moved parallel to the main body portion in a stable position, thereby ensuring that the switch is turned on.

[0014] Furthermore, preferably, the front panel portion is made of a light-transmitting material, and a light-emitting means is disposed inside the front panel portion and in front of the main body portion, so that light emitted from the light-emitting means is incident on the front panel portion and emitted from the front side. According to this configuration, it is possible to realize a transmitter with an integrated indicator light, which has an indicator light for indicating the position of the transmitter on the front side of the main body. Effect of the Invention

[0015] According to the present invention, even if the protective plate tilts when pressed, it can be stably moved parallel to turn on the switch reliably, and a transmitter can be realized in which there is no risk of the protective plate (push button) being damaged even if the protective plate is pressed with great force. [Brief description of the drawings]

[0016] [Figure 1] 1 is an overall perspective view showing an embodiment in which the present invention is applied to a fire alarm transmitter; [Diagram 2] 2 is a cross-sectional side view showing the internal structure of the transmitter shown in FIG. [Diagram 3] 3 is an enlarged cross-sectional view of a main part showing a part of the internal structure shown in FIG. 2. [Figure 4] 1 shows a specific example of an inner protective plate and a guide member that guides it in a transmitter of an embodiment, where (A) is a front view of the inner protective plate and the guide member, and (B) is a cross-sectional side view of the inner protective plate and the guide member. [Diagram 5] FIG. 1 shows a schematic configuration of a sliding body serving as a push button in a conventional transmitter and a guide member that guides it, in which (A) is a sectional side view showing the state immediately before a pushing force acts on the sliding body, and (B) is a sectional side view showing the state in which the sliding body has been pushed in. [Figure 6]1A and 1B show schematic configurations of a sliding body serving as a push button and a guide member that guides it in a transmitter according to an embodiment of the present invention, in which (A) is a schematic diagram showing a state immediately before a pushing force acts on the eccentric position of the sliding body, and (B) is a schematic diagram showing a state in which the sliding body has been pushed in. [Figure 7] 1A is a schematic diagram showing a state immediately before a pushing force acts on the eccentric position of the sliding body, and FIG. 1B is a schematic diagram showing a state in which the sliding body has been pushed in. FIG. 1B is a schematic diagram showing a state in which the sliding body has been pushed in. [Figure 8] FIG. 1 is a cross-sectional side view showing an example of the internal structure of a conventional fire alarm transmitter equipped with a tilting push button. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment in which the present invention is applied to a fire alarm transmitter equipped with an indicator lamp that indicates the position of the transmitter will be described with reference to the drawings. The fire alarm transmitter of this embodiment (hereinafter simply referred to as the transmitter) has the function of transmitting a signal to a fire receiver notifying the occurrence of an abnormality such as a fire by firmly pressing the push button on the front to turn on an internal switch, and is configured for use by being installed on the wall of a building or the surface panel of a fire hydrant box.

[0018] 1 and 2 show an embodiment of a transmitter to which the present invention is applied. Of these, Fig. 1 is an overall perspective view of the transmitter, and Fig. 2 is a sectional side view showing the internal structure of the transmitter shown in Fig. 1. As shown in FIG. 1, the transmitter of this embodiment is composed of a transmitter main body 10 equipped with a box-shaped storage case 12 with a built-in push button switch, and a disk-shaped front panel 20 connected to the front of the transmitter main body 10, which has a push button 21 that protects the push button switch located inside the center of the outer surface and has light-emitting sections 22 around it that function as position indicator lights.

[0019] As shown in FIG. 2, the push button (external protective plate) 21 has a rod-shaped pressing rod portion 21a that protrudes inward at the center of its back surface, and inside the storage case 12 of the transmitter main body 10, there is disposed an inner protective plate 13 that is disc-shaped and has a rod-shaped member 13a that protrudes inward at the center of the back surface so as to face the rear end surface of the pressing rod portion 21a. A circuit board 14 having a push button switch 11 mounted thereon is disposed within the storage case 12 at a position facing the rear end of the rod-shaped member 13a of the inner protective plate 13. Although not shown, this circuit board 14 is provided with a circuit that generates a signal when the push button switch 11 is turned on and sends the signal to the outside.

[0020] Furthermore, on the rear surface of the circuit board 14, a terminal block 15 is provided which is equipped with terminals to which ends of external wiring for transmitting signals to a fire control panel are connected. The storage case 12 is made of synthetic resin or the like, and is provided integrally with a guide member 16 having an inner guide portion 16a that fits with and guides the rod-shaped member 13a of the inner protective plate 13, and an outer guide portion 16b that guides the outer periphery of the inner protective plate 13. This structure will be described in detail later. A dust cover 17 is attached to the rear end of the storage case 12 to prevent the intrusion of dust and debris. Meanwhile, a flange-shaped plate portion 12a is provided on the front end side of the storage case 12, and a plurality of engagement claws 12b are provided on the outer surface side of the plate portion 12a.

[0021] 2, the front panel section 20 includes a disk-shaped main body plate 22A joined to cover the outer opening of the storage case 12 incorporating the push button switch 11, a light guide plate 22B joined to the outer surface of the main body plate 22A, and a cover member 22C joined to the outer surface of the light guide plate 22B. A push button 21 is disposed in the center of the front panel section 20 as an outer protective plate for protecting the push button switch 11. A holding member 25 having a cylindrical portion 25a for slidably holding a pressing rod portion 21a of the push button 21 is disposed on the rear side of the main body plate 22A.

[0022] In addition, the main plate 22A of the front panel portion 20 has a mortar-shaped portion 22b with a U-shaped cross-sectional engagement portion 22a on the inner end side, and a disk-shaped outer flat portion 22c provided around it, and a short cylindrical eaves portion 22d bent inwardly is formed on the peripheral edge of the outer flat portion 22c. In addition, a cylindrical portion 25a protruding inward is provided on the back surface of the retaining member 25 arranged on the back portion of the main body plate 22A, and the pressing rod portion 21a formed on the back surface of the push button 21 is inserted into this cylindrical portion 25a.

[0023] 3, a pair of locking claws 25b are formed on the inner peripheral surface of the cylindrical portion 25a, and a pair of grooves 21b are formed on the outer peripheral surface of the rod portion 21a, into which the locking claws 25b are engaged so as to be movable in the axial direction. The rear end of the groove 21b is closed and has a step, and when the push button 21 moves outward, the step comes into contact with the locking claws 25b, preventing further outward movement. In other words, it functions as a position restricting means for restricting the push button 21 from jumping outward. Moreover, a cylindrical wall portion 25c is provided on the front side of the holding member 25 so as to surround the pressing rod portion 21a of the push button 21, and this wall portion 25c functions as a stopper when the push button 21 is pressed in. Furthermore, a cylindrical engagement wall 25d is provided on the periphery of the front side of the holding member 25, which engages with the above-mentioned engagement portion 22a of the main body plate 22A.

[0024] The main body plate 22A of the front panel section 20 is connected to the front end of the storage case 12 by engaging an engagement claw 22h provided on the back surface thereof with an engagement claw 12b of the plate section 12a of the storage case 12. The main body plate 22A is configured so that the engagement claw 22h first comes into contact with the front end of the storage case 12 with the engagement claw 22h and the engagement claw 12b misaligned with each other in the circumferential direction, and then the main body plate 22A is rotated slightly so that the engagement claw 22h meshes with the engagement claw 12b. This allows the front panel section 20 to be attached to the outer surface side of the transmitter main body section 10. However, the main body plate 22A and the storage case 12 may be configured to be connected to each other by screws at the plate section 12a.

[0025] Meanwhile, the light guide plate 22B has a circular opening 22i formed in its center, through which the rod portion 21a of the push button 21 is inserted. Also, the light guide plate 22B has a cone-shaped portion in its center and a flat portion having an annular shape around the cone-shaped portion, in correspondence with the shape of the main body plate 22A, and a visor portion 22j having a short cylindrical shape bent inward is formed on the periphery of the flat portion. In addition, in the transmitter of this embodiment, an LED board 24 is arranged inside the cylindrical engagement wall 25d of the front panel portion 20, on which a plurality of light-emitting elements (LEDs: light-emitting diodes) 23 functioning as a light source are mounted with their emission portions facing outward. Furthermore, the light guide plate 22B has a light incident surface formed at the rear end of the edge of the central opening 22i, and the light emitting elements 23 are disposed so as to face the light incident surface. The light emitting elements 23 are disposed in an annular shape corresponding to the light incident surface at the edge of the opening 22i.

[0026] The pressing rod portion 21a of the push button 21 is movable back and forth along the inner surface of the cylindrical portion 25a of the holding member 25, and when the pressing portion on the outer surface of the push button 21 is pressed with a finger, the pressing rod portion 21a moves inward and its rear end face moves the inner protective plate 13 inside the storage case 12 inward, so that the rear end of the rod-shaped member 13a of the inner protective plate 13 hits the actuator of the push button switch 11, turning on the switch. Although not particularly limited, the push button 21 is formed from a light-transmitting material, and is configured so that a portion of the light emitted from the light-emitting element 23 enters the back of the push button 21 and exits from the outer surface, causing the surface of the push button 21 to emit light.

[0027] Furthermore, in the transmitter of this embodiment, a cylindrical guided portion 13b protruding rearward is provided on the peripheral edge of the inner protective plate 13, which is circular when viewed from the front, and a guide member 16 having an outer guide portion 16b that guides the guided portion 13b and an inner guide portion 16a that guides the rod-shaped member 13a of the inner protective plate 13 is integrally formed on the inner wall of the storage case 12 so as to surround the outside of the inner protective plate 13. Of these, the outer guide portion 16b has a J-shaped or U-shaped cross section, and as shown in Figure 4(A), slits 16s are provided on both sides to form four pressing portions 16c that function as spring pieces, spaced 90 degrees apart in the circumferential direction.

[0028] The diameter of the opening of the outer guide portion 16b of the guide member 16 is set slightly larger than the outer diameter of the cylindrical guided portion 13b of the inner protective plate 13, and is configured to have a gap G between the outer guide portion 16b and the guided portion 13b. The four pressing parts 16c are set so that the distance between the inner surfaces of the opposing pressing parts 16c is slightly smaller than the outer diameter of the guided part 13b of the inner protective plate 13. As a result, the outer peripheral surface of the guided part 13b of the inner protective plate 13 does not contact the inner peripheral surface of the outer guide part 16b of the guide member 16, but contacts the inner surface of the pressing parts 16c, and a force is constantly applied from the four pressing parts 16c to press the guided part 13b of the inner protective plate 13 from the outside toward the center. The number of pressing parts 16c is not limited to four, and may be three or five or more.

[0029] 2, between the guide member 16 and the inner protective plate 13 in the storage case 12, there are disposed return compression springs B1, B2 for biasing the inner protective plate 13 and the push button 21 forward. Also, as shown in Figure 4 (B), the tip (rear end) of the guided portion 13b of the inner protective plate 13 has an outward-facing claw 13c at a position corresponding to the above-mentioned four pressing portions 16c, and this claw 13c engages with the end of the pressing portion 16c, thereby preventing the inner protective plate 13 from moving forward due to the restoring force of the return spring and jumping out of the guide member 16.

[0030] Next, the function of the pressing portion 16c provided on the guide member 16 will be described in detail with reference to FIGS. In the case where the guide member 16 is not provided with the pressing portion 16c and is a simple cylindrical member 16d, as shown in FIG. 5(A), when a pressing force P acts on an eccentric position of the sliding body S (corresponding to the inner protective plate 13), as shown in FIG. 5(B), a rotational moment M is generated, causing the sliding body S to tilt and a part of the outer circumference (parts marked with circles K1 and K2) to come into contact with the cylindrical member 16d, and the pressure at the contact part increases, and the frictional force also increases, causing galling. Furthermore, when the pressing force P acting on the eccentric position increases, the rotational moment M in the direction that is easy to gall increases, further strengthening the galling, resulting in a vicious circle. When galling occurs, the sliding of the sliding body S may be hindered, and the switch may not be able to be turned on. Also, galling does not necessarily occur at both the points indicated by the symbols K1 and K2, and may occur only at one of them. Although not shown in FIG. 5, a switch is provided below the sliding body S, and the switch is turned on when the sliding body S is pressed downward.

[0031] On the other hand, in the transmitter of this embodiment, the guide member 16 is provided with a pressing portion 16c, and as shown in Fig. 6(A), a part of the pressing portion 16c is in contact with the outer circumferential surface of the sliding body S, so that when a pressing force P acts on an eccentric position of the sliding body S, as shown in Fig. 6(B), the sliding body S tilts, one pressing portion 16c (on the right side in the figure) undergoes large elastic deformation and the repulsive force R increases, but the other pressing portion 16c (on the left side in the figure) undergoes less deformation and the repulsive force R decreases. As a result, a rotational moment M' in the opposite direction to the rotational moment M is generated with respect to the sliding body S, which reduces the tilt of the sliding body S, making it easier to press the sliding body S and less likely to cause galling at the contact portion.

[0032] As described above, in the transmitter of this embodiment, the guide member 16 that guides the inner protective plate 13 is provided with a plurality of elastically deformable pressing portions 16c that come into contact with the outer peripheral surface of the inner protective plate 13, so that the inner protective plate 13 moves in parallel even if a pressing force acts on an eccentric position when the push button 21 is pressed to move the inner protective plate 13 to the rear, or even if the front surface of the inner protective plate 13 is tilted. This prevents galling from occurring between the inner protective plate 13 and the guide member 16, and ensures that the internal switch is turned on.

[0033] In this embodiment, the cover member 22C of the front panel 20 is made of a soft material such as silicone resin that is translucent and can retain its shape, and the surface of this shape-retaining member is covered with a skin 22k made of fabric or the like made of a flexible, heat-resistant, and elastic material such as meta-amide fiber. The cover member 22C is formed to cover the eaves portion 22j at the outer edge of the light guide plate 22B from the side to the back. As a result, even if an external impact is applied to the cover member 22C, the shape-retaining member deforms to absorb the impact, preventing damage to the surface, and is configured to increase visibility from the side of the transmitter by emitting light from the eaves portion 22j. In addition, since the surface of the shape-retaining member is covered with a fabric skin 22k, the light guided by the light guide plate 22B is diffused or transmitted and emitted to the outside, giving it a soft and vague texture. The skin 22k of the cover member 22C is woven in a way that allows it to exhibit stretchable properties.

[0034] Also, the inner edge of the shape-retaining member of the cover member 22C stops near the outer periphery of the push button 21, but the skin 22k is formed to extend further inward. An opening of the same size as the outer diameter of the pressing rod portion 21a of the push button 21 is formed in the center of the skin 22k, and the pressing rod portion 21a is inserted into this opening. This results in a configuration in which the back surface of the flange portion of the push button 21 presses the center of the skin 22k toward the storage case 12. At this time, the skin 22k is pulled inward and stretched, and this tension acts as a force to press the push button 21 outward. As a result, even if a spring that biases the push button 21 outward is not provided in the storage case 12, it is possible to impart a resistance when the push button 21 is pressed and a force to return the push button 21 to its original position.

[0035] Furthermore, as shown in FIG. 2, when the back surface of push button 21 is pressed against the center of skin 22k of front panel portion 20, the center of cover member 22C is recessed toward storage case 12, and the outer surface of push button 21 is positioned inward from the most bulging part of the outer surface of cover member 22C, thereby preventing the push button 21 from being accidentally pressed, turning on the switch, and transmitting an erroneous signal to the receiver. When the pressure from the push button 21 is released and the cover 22k returns to its fixed position due to the tension, the push button switch 11 in the storage case 12 is turned off, but the fire alarm state is self-maintained by the electric circuit provided on the circuit board 14. Therefore, the fire alarm state is maintained even if the push button switch 11 is turned off. The state maintained by the electric circuit on the circuit board 14 is released by a recovery pulse from the receiver.

[0036] (Modification) Next, a modification of the transmitter of the above embodiment will be described with reference to FIG. In this modified example, instead of providing a pressing portion 16c on the guide member 16, as shown in FIG. 7(A), rectangular pressing plates 16A, 16B are arranged at the position where the pressing portion 16c is to be provided, and compression springs 18A, 18B that urge the pressing plates 16A, 16B toward the center are respectively interposed between the pressing plates 16A, 16B and the inner peripheral wall of the cylindrical guide member 16. The pressing plates 16A, 16B are configured to come into contact with the outer peripheral surface of the sliding body S by being pressed by the compression springs 18A, 18B. The pressure plates are provided at four locations in the circumferential direction at 90 degree intervals, and FIG. 7 shows a pair of opposing pressure plates 16A, 16B.

[0037] In this modified example, similarly to the above embodiment, when a pressing force P acts on an eccentric position of the sliding body S, as shown in Fig. 7(B), a rotational moment M is generated and the sliding body S tilts, and the compression springs 18A, 18B deform and the pressing plates 16A, 16B tilt following the sliding body S. Therefore, a difference occurs in the repulsive forces (restoring forces) of the upper and lower compression springs 18A, 18B, and a rotational moment in the opposite direction to the above is generated with respect to the sliding body S, which reduces the tilt of the sliding body S, making it easier to press the sliding body S and less likely to cause galling at the contact portion.

[0038] Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-mentioned embodiments. For example, in the above-mentioned embodiments, the front panel 20 having a light-emitting portion that functions as an indicator lamp indicating the position of the transmitter is provided on the front of the transmitter main body 10, but the present invention can be applied to a transmitter having a configuration in which the front panel 20 is omitted and the inner protective plate 13 is exposed on the front as a push button. Furthermore, in the above embodiment, the protective plate 21 is configured to return to its original position when the force pushing the protective plate 21 is released, but it is also possible to provide a mechanism for maintaining the protective plate 21 in a pushed-in state and a means for releasing the force.

[0039] In addition, the embodiment in Figures 2 and 3 shows an application to a transmitter having a structure in which the transmitter body 10 and the front panel 20 can be separated, but it is particularly effective to apply the sliding structure of the present invention to a transmitter having a conventional structure in which the front panel cannot be separated and in which the inner protective plate 13 of this embodiment is exposed at the position of the push button (outer protective plate) 21. In addition, in the above embodiment, the front panel portion 20 is circular when viewed from the front, but it may be elliptical or polygonal. Furthermore, in the above embodiment, the present invention has been described as being applied primarily to a fire transmitter that constitutes a fire alarm system, but the present invention is not limited to fire transmitters and can be widely used in train emergency alert transmitters installed on station platforms and at railroad crossings, and emergency call transmitters installed in toilets, bathrooms, etc. [Explanation of symbols]

[0040] 10 Transmitter body 11 Push button switch 12 Storage case 12a Flange-shaped plate portion 12b Engagement claw 13 Inner protection plate 14 Circuit Board 15 Terminal block 16 Guide member 16a Inner guide part 16b Outer guide part 16c Pressing part (contact piece) 20 Front panel (outer cover) 21 Push button (outer protective plate) 21a Pressing rod part 21b Groove 22 Light emitting part 22A Body Plate 22B Light guide plate 22C Cover material 22a Engagement portion of main body plate 22b Cone-shaped portion of main plate 22c Outer flat part of main plate 22d Main plate eaves 22e Cylindrical part of the main plate 22h engaging claw 22i aperture 22j Eaves 22k epidermis 23 Light emitting element (LED) 24 LED board 25 Retaining member 25a Cylindrical part 25b Locking claw 25d engaging wall

Claims

1. A transmitter comprising: a main body having a built-in push button switch that is turned on by pressing the main body from the outside; and a protective plate having a planar pressing portion and disposed outside the push button switch, the push button switch being turned on when the protective plate is pressed, The protective plate includes a guided portion, a guide member that guides the guided portion in a push-in direction of the protection plate, the guide member being provided on the main body portion; This transmitter is characterized in that the guide member has a plurality of contact pieces that are capable of contacting the outer surface of the guided portion and surround the guided portion, and the plurality of contact pieces are configured to be pressed against the outer surface of the guided portion toward the center of the protective plate by elastic force.

2. 2. The transmitter according to claim 1, wherein the contact piece is an elastically deformable leaf spring formed by providing a pair of slits in the guide member.

3. The transmitter described in claim 1, characterized in that the contact piece consists of a plate member arranged to face the outer surface of the guided portion, and is pressed against the outer surface of the guided portion toward the center of the protective plate by the elastic force of a spring member arranged between the plate member and the outer surface of the guided portion.

4. a spring member is provided on the rear portion of the protective plate to bias the protective plate in a direction opposite to the pushing direction; 4. The transmitter according to claim 1, wherein an end of the protective plate of the guided portion in the pushing direction is provided with a claw portion capable of engaging with an edge of the guide member to prevent the protective plate from popping out.

5. a front panel portion having a central opening and disposed outside the main body portion; 4. A transmitter as described in any one of claims 1 to 3, characterized in that an outer protective plate is arranged in the opening of the front panel portion, the outer protective plate having a planar pressing portion and a rod portion provided on the back surface of the pressing portion, the end of the rod portion being in contact with the pressing portion of the protective plate.

6. The transmitter according to claim 5, characterized in that the front panel portion is made of a light-transmitting material, a light-emitting means is disposed inside the front panel portion and in front of the main body portion, and light emitted from the light-emitting means is incident on the front panel portion and emitted from the front side.

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