CN220491395U - Smoke alarm - Google Patents

Abstract

The utility model discloses a smoke alarm, relates to the technical field of Internet of things, and is used for improving the indication effect of the smoke alarm. The utility model discloses a smoke alarm, comprising: protective housing, smoke transducer, pilot lamp, ringing slide and cleaning board, protective housing includes: the internal surface, the pilot lamp has the warning state, and the pilot lamp is connected with smoke transducer, and the pilot lamp runs through protective housing, sliding connection between the internal surface of ring slide and protective housing, cleans board and ring slide connection, cleans the board and is used for clearing up the pilot lamp. The ringing skateboard has a sliding state; when the ringing slide plate is in a sliding state, the ringing slide plate drives the cleaning plate to slide, so that the cleaning plate cleans the indicator lamp.

Description

Smoke alarm

Technical Field

The utility model relates to the technical field of the Internet of things, in particular to a smoke alarm.

Background

The smoke alarm is a fire-fighting infrastructure with wide application, can collect the concentration signal of smoke in the environment where the smoke alarm is installed, and can judge the smoke concentration signal so as to generate an alarm in the early stage of fire disaster to prevent the fire disaster.

Currently, smoke alarms can alarm by flashing indicator lights. However, since the indicator lamp of the smoke alarm is exposed to the air for a long time, a large amount of dust may be accumulated on the surface of the indicator lamp. Thicker dust may block the illumination of the indicator light, reducing the brightness of the indicator light, and thus causing a reduction in the indication effect of the alarm.

Disclosure of Invention

The utility model provides a smoke alarm which is used for improving the indication effect of the smoke alarm.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

in a first aspect, an embodiment of the present utility model provides a smoke alarm comprising: protective housing, smoke transducer, pilot lamp, ringing slide and cleaning board, protective housing includes: the internal surface, the pilot lamp has the warning state, and the pilot lamp is connected with smoke transducer, and the pilot lamp runs through protective housing, sliding connection between the internal surface of ring slide and protective housing, cleans board and ring slide connection, cleans the board and is used for clearing up the pilot lamp. The ringing skateboard has a sliding state. When the ringing slide plate is in a sliding state, the ringing slide plate drives the cleaning plate to slide, so that the cleaning plate cleans the indicator lamp.

Optionally, the smoke alarm further comprises: the driving motor and the extrusion stick, the driving motor is fixed at the internal surface of protective housing, rotate between extrusion stick and the internal surface of protective housing and be connected, extrusion stick orientation bell slide.

Optionally, the driving motor includes an output end, and the extrusion rod is mounted at the output end of the driving motor. The squeeze bar has a vertical state and a horizontal state. When the extrusion rod is in a vertical state, the extrusion rod does not extrude the ringing slide plate, and the ringing slide plate is in a non-sliding state; when the extrusion rod is in a horizontal state, the extrusion rod extrudes the ringing slide plate so that the ringing slide plate slides to the pole.

Optionally, a spring is connected between the protective shell and the ringing slide plate.

Optionally, the bell skateboard is provided with bell.

Optionally, the protective shell further comprises an outer surface, and a filter screen is arranged on the outer surface of the protective shell and is adjacent to the bell.

Optionally, the smoke alarm further comprises: the device comprises a pressing device and a mounting box, wherein the pressing device comprises a pressure plate, the pressing device is connected with the inner surface of the protective shell in a sliding mode, the pressure plate is connected with the mounting box in a sliding mode, the mounting box is fixed on the inner surface of the protective shell, and the mounting box is provided with a groove used for placing dry ice. The pressure plate has a sliding state. When the pressure plate is in a sliding state, the pressure plate may press the dry ice in the groove to release the dry ice from the installation box.

Optionally, the pressing device further includes: the device comprises a linkage shaft and a linkage plate, wherein the linkage shaft is rotationally connected with the inner surface of a protective shell, a belt is arranged between the linkage shaft and the output end of a driving motor, the linkage plate is in sliding connection with the inner surface of the protective shell, the linkage shaft is provided with tooth blocks, the linkage plate faces the linkage shaft and is provided with tooth blocks, the linkage shaft is in meshed connection with the linkage plate, and the linkage plate is provided with a pressure plate.

Optionally, the smoke alarm further comprises a storage battery, and the storage battery is fixed on the inner surface of the protective shell.

The smoke alarm provided by the embodiment of the utility model comprises: protective housing, smoke transducer, pilot lamp, ringing slide, cleaning board, protective housing includes: the internal surface, the pilot lamp has the warning state, and the pilot lamp runs through the protective housing, sliding connection between the internal surface of ring slide and protective housing, cleans board and ring slide connection, cleans the board and is used for clearing up the pilot lamp. The bell slide has the slip state, and when the bell slide was in the slip state, the bell slide drove the cleaning board and slides to make the cleaning board clear up the pilot lamp. Therefore, the cleaning plate can clean the indicator lamp, reduce dust accumulated on the indicator lamp, and improve the brightness of the indicator lamp so as to improve the indication effect of the smoke alarm.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic side sectional view of a smoke alarm according to an embodiment of the present utility model;

fig. 2 is a schematic side view of a smoke alarm according to an embodiment of the present utility model;

FIG. 3 is a schematic side sectional view of another smoke alarm according to an embodiment of the present utility model;

fig. 4 is a schematic front sectional view of a smoke alarm according to an embodiment of the present utility model;

fig. 5 is a schematic diagram of a front structure of a smoke alarm according to an embodiment of the present utility model;

fig. 6 is a schematic diagram of another front cross-sectional structure of a smoke alarm according to an embodiment of the present utility model;

fig. 7 is a schematic diagram of another front cross-sectional structure of the smoke alarm according to the embodiment of the present utility model;

fig. 8 is a schematic diagram of another front cross-sectional structure of the smoke alarm according to the embodiment of the present utility model;

fig. 9 is a schematic side sectional view of another smoke alarm according to an embodiment of the present utility model.

Reference numerals:

101-a protective housing; 102-a smoke sensor; 103-an indicator light; 104-ringing skateboard; 105-cleaning plate; 106, a dustproof baffle; 107-hairbrush; 301-driving a motor; 302-extruding a rod; 303-an output of a drive motor; 401-a spring; 402-bell; 501-a filter screen; 601-pressing means; 602-mounting box; 603-a pressure plate; 604-a dry ice bin; 701-a linkage shaft; 702-linkage plates; 703-a belt; 801-a battery.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, it should be noted that the terms "mounted," "connected," and "coupled" are to be construed broadly, as well as, for example, fixedly coupled, detachably coupled, or integrally coupled, unless otherwise specifically indicated and defined. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

The terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, unless otherwise indicated, the meaning of "a plurality" is two or more.

The internet of things refers to collecting various information of objects or processes through various information sensor devices and technologies, so that ubiquitous connection of objects and ubiquitous connection of objects and people is realized. Through the application of the Internet of things, people can know the information of the object of interest in real time, so that the purposes of monitoring, connecting or interacting the object or process are achieved.

The smoke alarm is a fire-fighting infrastructure with wide application, can collect the concentration signal of smoke in the environment where the smoke alarm is installed, and can judge the smoke concentration signal so as to generate an alarm in the early stage of fire disaster to prevent the fire disaster.

Currently, smoke alarms can alarm by flashing indicator lights. However, since the indicator lamp of the smoke alarm is exposed to the air for a long time, a large amount of dust may be accumulated on the surface of the indicator lamp. Thicker dust may obscure the illumination of the indicator light, resulting in a reduced indication effect of the alarm.

In order to solve the above problems, an embodiment of the present utility model provides a smoke alarm including: protective housing, smoke transducer, pilot lamp, ringing slide, cleaning board, protective housing includes: the internal surface, the pilot lamp has the warning state, and the pilot lamp runs through the protective housing, sliding connection between the internal surface of ring slide and protective housing, cleans board and ring slide connection, cleans the board and is used for clearing up the pilot lamp. The bell slide has the slip state, and when the bell slide was in the slip state, the bell slide drove the cleaning board and slides to make the cleaning board clear up the pilot lamp.

An embodiment of the utility model provides a smoke alarm, and fig. 1 shows a schematic side sectional structure of the smoke alarm. As shown in fig. 1, the smoke alarm includes: a protective housing 101, a smoke sensor 102, an indicator light 103, a bell slide 104, and a cleaning plate 105.

Wherein the protective housing 101 comprises an inner surface. The protective housing 101 may be used to carry the internal components of the smoke alarm and may protect the internal components from damage.

The thickness of the protective case 101 is shown by two rectangular frames in fig. 1. The internal components may include: smoke sensor 102, indicator light 103, and ringing slide 104.

The smoke sensor 102 may be used to detect the concentration of smoke in the area where the smoke alarm is located.

Specifically, the smoke sensor 102 may be an ionic smoke sensor, and the smoke sensor 102 may also be a photoelectric smoke sensor.

An indicator light 103 extends through the protective housing 101. The indicator light 103 has an alarm state, and when the indicator light 103 is in the alarm state, the indicator light 103 may emit a blinking light.

In one design, indicator light 103 is coupled to smoke sensor 102. The smoke sensor 102 may detect a smoke concentration, and if the smoke concentration is greater than a preset concentration threshold, the smoke sensor 102 may generate an alarm signal. In response to the alarm signal, the smoke alarm can turn on the indicator lamp 103, and the indicator lamp 103 emits flashing light to alarm.

The preset concentration threshold value is not limited. For example, the preset concentration threshold may be 10%. For another example, the preset concentration threshold may be 18%. For another example, the preset concentration threshold may be 20%.

The cleaning plate 105 is slidably connected to the bell slide 104 and the cleaning plate 105 is adapted to clean the indicator light 103, and is slidably connected to the inner surface of the protective housing 101.

Since the indicator lamp 103 penetrates the protective case 101, a part of the area of the indicator lamp is not shielded by the protective case 101, and dust is easily accumulated. While the cleaning plate 105 is used for cleaning the indicator light 103, the cleaning plate 105 may be located outside the protective housing, and is specifically used for cleaning an area of the indicator light 103 where the protective housing 101 is not shielded.

The sweeping plate 105 may be provided with a dust guard 106. The dust barrier 106 may be used to block dust from entering the protective housing.

Therefore, the dustproof baffle plate can prevent dust from entering the protective shell from the joint of the cleaning plate and the ringing slide plate, and damage to internal components caused by the dust is avoided.

In one design, ringing slide 104 has a sliding state. When the ringing slide plate 104 is in a sliding state, the ringing slide plate 104 can drive the cleaning plate to slide, so that the cleaning plate can clean the indicator lamp 103.

Specifically, the cleaning plate 105 may be provided with a brush 107, and the brush 107 of the cleaning plate 105 faces the indicator lamp 103. The cleaning plate 105 can clean the indicator lamp 103 by the brush 107.

In some embodiments, in conjunction with fig. 1, as shown in fig. 2, fig. 2 shows a schematic side structural view of a smoke alarm.

The smoke alarm provided by the embodiment of the utility model has at least the following beneficial effects: the smoke alarm includes: protective housing, smoke transducer, pilot lamp, ringing slide, cleaning board, protective housing includes: the internal surface, the pilot lamp has the warning state, and the pilot lamp runs through the protective housing, sliding connection between the internal surface of ring slide and protective housing, cleans board and ring slide connection, cleans the board and is used for clearing up the pilot lamp. The bell slide has the slip state, and when the bell slide was in the slip state, the bell slide drove the cleaning board and slides to make the cleaning board clear up the pilot lamp. Therefore, the cleaning plate can clean the indicator lamp, reduce dust accumulated on the indicator lamp, and improve the brightness of the indicator lamp so as to improve the indication effect of the smoke alarm.

In some embodiments, in conjunction with fig. 1, as shown in fig. 3, fig. 3 shows another schematic side cross-sectional view of a smoke alarm. The smoke alarm provided by the utility model can further comprise: a drive motor 301 and a squeeze bar 302.

Wherein, the driving motor 301 is fixed on the inner surface of the protective housing 101, and the driving motor 301 is used for converting electric energy into mechanical energy.

It should be noted that, if the smoke concentration is greater than the preset concentration threshold, the smoke sensor 102 generates an alarm signal. The smoke alarm may also turn on the drive motor 301 in response to the alarm signal.

The squeeze bar 302 is rotatably coupled to the inner surface of the guard casing 101. Squeeze bar 302 faces ringing slide 104.

It should be noted that, because squeeze bar 302 is hidden by ringing slide 104, squeeze bar 302 is represented by the dashed square on ringing slide 104 in fig. 3. In the present utility model, the end of squeeze bar 302 facing ringing slide 104 may be arcuate in design. In this manner, wear between squeeze bar 302 and ringing slide 104 may be reduced.

In one design, drive motor 301 may drive squeeze bar 302 to rotate such that squeeze bar 302 squeezes ringing slide 104, and ringing slide 104 slides.

Specifically, the drive motor 301 includes an output end 303, and the squeeze bar 302 is mounted to the output end 303 of the drive motor 301. The driving motor 301 can receive electric energy and drive the output end 303 to rotate, and the output end 303 of the driving motor drives the extrusion rod 302 to rotate.

Wherein the squeeze bar 302 has a vertical state and a horizontal state. When the squeeze bar 302 is in the vertical state, the squeeze bar 302 does not push the ringing slide plate 104, and the ringing slide plate 104 is in the non-sliding state. When the squeeze bar 302 is in the horizontal state, the squeeze bar 302 pushes the ringing slide plate 104 so that the ringing slide plate 104 slides to the pole.

Note that the sliding range of the ringing slide 104 includes: the range between the position where the ringing slide plate is located when the ringing slide plate is in the non-sliding state and the position where the ringing slide plate is located when the ringing slide plate slides to the pole. The cleaning range of the cleaning plate 105 is the same as the sliding range of the ringing slide 104.

In another design, squeeze bar 302 may be a squeeze bar of a telescoping design, and drive motor 301 may drive squeeze bar 302 to telescope, such that squeeze bar 302 squeezes ringing slide 104, and ringing slide 104 slides.

It can be appreciated that the smoke alarm provided by the embodiment of the utility model further comprises: the driving motor and the extrusion stick, the driving motor is fixed at the internal surface of protective housing, rotate between extrusion stick and the internal surface of protective housing and be connected, extrusion stick orientation bell slide. The driving motor can drive the extrusion rod to rotate through the output end so that the extrusion rod pushes the ringing slide plate to slide.

In some embodiments, and in connection with fig. 3, as shown in fig. 4, fig. 4 shows a schematic illustration of an elevational cross-section of a smoke alarm.

Fig. 4 is a left-right symmetrical image, that is, the smoke alarm shown in fig. 4 has two smoke sensors 102, two indicator lamps 103, two bell skateboards 104, two cleaning boards 105, one driving motor 301, and two squeeze bars 302. In the present utility model, the number of internal components is not limited.

A spring 401 is connected between the protective housing 101 and the ringing slide 104. The squeeze bar 302 can compress the spring 401 while the squeeze bar 302 pushes the ringer slide 104 while the drive motor 301 rotates the squeeze bar 302 through the output end 303.

It should be noted that, in the case where the ringing slide 104 slides to the pole, the spring 401 may push the ringing slide 104 to reset the ringing slide 104. Thus, by pushing the pressing bar 302 and the spring 401, the ringing slide plate 104 can be repeatedly slid.

In some embodiments, as shown in FIG. 4, ring slide 104 is provided with bell 402. In the case where bell slide 104 is slid, bell slide 104 may vibrate bell 402 to cause bell 402 to generate sound.

Thus, the bell 402 can generate sound when vibrating, and the smoke alarm can alarm through sound so as to improve the indication effect of the smoke alarm.

In some embodiments, as shown in fig. 5, fig. 5 shows a schematic front view of a smoke alarm. The protective housing 101 further includes an outer surface, and the outer surface of the protective housing 101 is provided with a screen 501, and the screen 501 is adjacent to the bell 402.

Thus, the filter 501 is disposed near the bell 402, which ensures the sound transmission of the bell 402 and prevents dust from entering the protective housing 101.

It should be noted that, the existing smoke alarm may fail due to high temperature in fire, so as to reduce alarm time and reduce practicability of the smoke alarm. The smoke alarm provided by the utility model adopts a dry ice cooling mode, so that the damage of internal components caused by high temperature is avoided.

In some embodiments, in conjunction with fig. 4, as shown in fig. 6, fig. 6 shows another schematic elevational view of the smoke alarm in cross-section. The smoke alarm provided by the utility model can further comprise: a pressing device 601 and a mounting box 602.

Wherein the pressing means 601 comprises a pressure plate 603, the pressing means 601 being slidingly connected to the inner surface of the protective housing 101. The sliding connection between the pressure plate 603 and the mounting box 602.

The mounting box 602 is fixed to the inner surface of the protective housing 101, and the mounting box 602 is provided with a groove for placing dry ice.

Specifically, a dry ice bin 604 is disposed in a recess of the mounting box 602, and the dry ice bin 604 may be used to store dry ice. The upper end of the dry ice bin 604 is a balloon made of rubber, and the lower end of the dry ice bin is provided with a pressure valve.

In one design, the pressure plate 603 has a sliding state. When the pressure plate 603 is in a sliding state, the pressure plate 603 may press the dry ice in the groove to release the dry ice from the mounting box 602.

Specifically, when the pressure plate 603 is in a sliding state, the pressure plate 603 may press a balloon at the upper end of the dry ice bin 604 in the groove, so that dry ice is ejected from a pressure valve at the lower end of the dry ice bin 604.

It will be appreciated that the smoke alarm further comprises: the device comprises a pressing device and a mounting box, wherein the pressing device comprises a pressure plate, the pressing device is connected with the inner surface of the protective shell in a sliding mode, the pressure plate is connected with the mounting box in a sliding mode, the mounting box is fixed on the inner surface of the protective shell, and the mounting box is provided with a groove used for placing dry ice. The pressure plate has a sliding state. When the pressure plate is in a sliding state, the pressure plate may press the dry ice in the groove to release the dry ice from the installation box. Therefore, the dry ice is released into the protective shell, so that the temperature of the internal components can be reduced, and the situation that the internal components cannot work due to high-temperature damage is reduced.

In some embodiments, in conjunction with fig. 6, as shown in fig. 7, fig. 7 shows another schematic elevational view of the smoke alarm in cross-section. The pressing device 601 further includes: a linkage shaft 701 and a linkage plate 702.

Wherein, the linkage shaft 701 is rotatably connected with the inner surface of the protective housing 101, a belt 703 is arranged between the linkage shaft 701 and the output end of the driving motor 301, a linkage plate 702 is slidably connected with the inner surface of the protective housing 101, the linkage shaft 701 is provided with a tooth block, the linkage plate 702 is provided with a tooth block towards the linkage shaft 701, the linkage shaft 701 is engaged with the linkage plate 702, and the linkage plate 702 is provided with a pressure plate 603.

Specifically, both ends of the linkage plate 702 are provided with pressure plates 603.

In one design, the driving motor 301 drives the linkage shaft 701 to rotate through the belt 703, so that the linkage shaft 701 drives the tooth block on one side of the linkage plate 702 to move through the tooth block, and the linkage plate 702 slides. When the linkage shaft 701 drives the tooth block at the other side of the linkage plate 702 to move, the linkage plate 702 slides reversely.

For example, referring to fig. 6, if the linkage plate moves downward when the linkage shaft drives the tooth block on the left side of the linkage plate, the linkage plate moves upward when the linkage shaft drives the tooth block on the right side of the linkage plate.

Thus, the linkage plate 702 can drive the pressure plate 603 to slide, so as to squeeze the upper end of the dry ice bin 604, and the dry ice is ejected from the pressure valve of the dry ice bin 604.

In some embodiments, in conjunction with fig. 7, as shown in fig. 8, fig. 8 shows another schematic front cross-sectional view of the smoke alarm. The smoke alarm provided by the utility model can further comprise: a battery 801, the battery 801 is fixed to the inner surface of the protective case 101, and the battery 801 can be used for power supply. The battery 801 is provided with a controller and a communication module.

Among other things, the controller may be used to control the turning on and off of the smoke sensor 102, the indicator light 103 and the drive motor 301. The communication module may be used to send alert information to the terminal. The communication module is connected with the terminal in a wired/wireless way.

In some embodiments, referring to fig. 1 and 8, as shown in fig. 9, fig. 9 shows another schematic side cross-sectional view of a smoke alarm.

It will be appreciated that the smoke alarm further comprises a battery secured to the inner surface of the protective housing. Therefore, if the power is off in the environment where the smoke alarm is installed, the storage battery can still supply power for the smoke alarm, so that the smoke alarm works normally, and the practicability of the smoke alarm can be improved.

In the description of the present specification, a particular feature, structure, or characteristic may be combined in any suitable manner in one or more embodiments or examples.

The foregoing is merely illustrative embodiments of the present utility model, but the scope of the present utility model is not limited thereto, and any person skilled in the art can easily think about variations or substitutions within the technical scope of the present utility model, and the utility model should be covered. Therefore, the protection scope of the utility model is subject to the protection scope of the claims.

Claims (9)

1. A smoke alarm, the smoke alarm comprising: protective housing, smoke transducer, pilot lamp, ringing slide and clean the board, protective housing includes: the inner surface is provided with an alarm state, the indicator lamp is connected with the smoke sensor, the indicator lamp penetrates through the protective shell, the bell slide plate is connected with the inner surface of the protective shell in a sliding manner, the cleaning plate is connected with the bell slide plate, and the cleaning plate is used for cleaning the indicator lamp;

the ringing skateboard has a sliding state; when the ringing slide plate is in the sliding state, the ringing slide plate drives the cleaning plate to slide, so that the cleaning plate cleans the indicator lamp.

2. The smoke alarm of claim 1 wherein said smoke alarm further comprises: the driving motor is fixed on the inner surface of the protective shell, the extrusion rod is rotationally connected with the inner surface of the protective shell, and the extrusion rod faces the ringing slide plate.

3. The smoke alarm of claim 2 wherein said drive motor includes an output end, said squeeze bar being mounted at said drive motor output end;

the extrusion bar has a vertical state and a horizontal state; when the extrusion rod is in a vertical state, the extrusion rod does not extrude the ringing slide plate, and the ringing slide plate is in a non-sliding state; when the extrusion rod is in a horizontal state, the extrusion rod extrudes the ringing slide plate so that the ringing slide plate slides to a pole.

4. A smoke alarm according to any one of claims 1 to 3 wherein a spring is connected between the guard housing and the ringing slide.

5. A smoke alarm according to any one of claims 1-3 wherein the ringing slide is provided with bell.

6. The smoke alarm of claim 5 wherein said protective housing further comprises an outer surface, said outer surface of said protective housing being provided with a screen, said screen being adjacent to said bell.

7. A smoke alarm according to any one of claims 1-3, wherein the smoke alarm further comprises: the device comprises a pressing device and a mounting box, wherein the pressing device comprises a pressing plate, the pressing device is in sliding connection with the inner surface of the protective shell, the pressing plate is in sliding connection with the mounting box, the mounting box is fixed on the inner surface of the protective shell, and the mounting box is provided with a groove used for placing dry ice;

the pressure plate has a sliding state; when the pressure plate is in a sliding state, the pressure plate may press the dry ice in the groove to release the dry ice from the mounting box.

8. The smoke alarm of claim 7 wherein said pressing means further comprises: the device comprises a linkage shaft and a linkage plate, wherein the linkage shaft is rotationally connected with the inner surface of the protective shell, a belt is arranged between the linkage shaft and the output end of the driving motor, the linkage plate is in sliding connection with the inner surface of the protective shell, the linkage shaft is provided with tooth blocks, the linkage plate faces the linkage shaft and is provided with tooth blocks, the linkage shaft is in meshed connection with the linkage plate, and the linkage plate is provided with a pressure plate.

9. A smoke alarm according to any one of claims 1 to 3 further comprising a battery secured to the inner surface of the protective housing.