Patent Abstract:
A complex respirator is provided that includes a first shell, at least a first filter layer and a second filter layer. The first filter layer is replaceable and arranged on an outer side of the first shell while the first shell is disposed on an outer side of the second filter layer. A slot is formed on an outer side of the first shell for accommodating the first filter layer. The filtering area of the first filter layer is smaller than that of the second filter layer while pore size of the first filter layer is larger than that of the second filter layer. The second filter layer filters the gas that the first filter layer is unable to filter. Moreover, the type of first filter media of the first filter layer may be chosen based on the location that the complex respirator is to be used.

Full Description:
REFERENCE TO RELATED APPLICATIONS 
     This Application is a Continuation-in-Part of patent application Ser. No. 11/335,073, filed 18 Jan. 2006, now U.S. Pat. No. 7,237,550. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a complex respirator, especially to a complex respirator with replaceable filter so that the storage of the respirator is easier and the filter is selectable with various pore sizes for filtering different kinds of gas. 
     The problem of air pollution is getting worse nowadays. No matter whether the pollution is from a dust storm, heavy smoke discharged from the factory, vehicle exhaust emission, or even smoke from waste combustion, all include toxic gas or granules harmful to human bodies, both are health risk factors. For the sake of protection and prevention, people wear respirators all the time so as to avoid inhalation of toxic gas and harmful granules while going out. Thus, the use rate of the respirator has risen. Most of the conventional respirators are disposable and have charcoal or “filtering fiber as filter media. Referring to  FIG. 1 , the fiber shown is disclosed in U.S. Pat. No. 6,234,171, B1—MOLDED RESPIRATOR CONTAINING SORBENT PARTICLES. The respirator is disposed with fiber  1  attached with sorbent particles  12 . Because a unit area of the fiber  1  only adheres a certain amount of the sorbent particles  12 , the sorbent particles  12  are easily saturated and are then unable to absorb any more toxic or harmful material. 
     Furthermore, the conventional flat respirator can&#39;t attach on a user&#39;s face tightly, so that a gap is formed between the edge of the respirator and the face skin. While wearing the flat respirator, part of the air with toxic gas or granules may flow through the gap and the gas enters the user&#39;s body. Thus a respirator  20  with a cartridge  22  in  FIG. 2  was developed. The traditional cartridge is filled with an adsorbent material as a filter media for filtering the air. Generally, the absorbent material is charcoal to absorb organic solvents and granules. However, the breathing area of the respirator  20  with the cartridge  22  is limited inside the cartridge  22  and includes pores with a small diameter. Therefore, such a respirator makes breathing difficult. In order to get more air flow, people need to breathe more heavily. Although the purpose of avoiding toxic gas or harmful materials is achieved, people feel uncomfortable while breathing. Thus people would not like to wear that kind of respirator while going out to areas with polluted air. 
     With either the conventional flat respirator or the respirator with the cartridge, the whole respirator needs to be thrown away when the filter is saturated and unable to be used anymore. This causes a kind of waste. Not only do those working in special locations, such as hospitals, use respirators, but also ordinary people do as well. Thus, there is a need to improve the way used filter material is replaced. 
     Due to a worsening environment, air pollution has become a pressing problem of public health. Thus, the present invention provides a complex respirator that not only protects people from inhaling toxic gas and harmful granules, but also allows users to breathe more smoothly. Moreover, only the filter layer of the respirator needs to be changed and the service time of the respirator is thereby extended. 
     SUMMARY OF THE INVENTION 
     Therefore it is a primary object of the present invention to provide a complex respirator that includes a replaceable first filter layer so that users can choose material of the first filter layer depending on places they intend to go. Thus toxic gas or harmful granules in the air people have inhaled will have been filtered. 
     It is another object of the present invention to provide a complex respirator that includes two filter layers made from different materials with a different area and pore size, so as to filter different granules. Thus, users won&#39;t inhale toxic gas or harmful granules in the air. 
     It is a further object of the present invention to provide a complex respirator with a replaceable filter layer, where the used filter layer is able to be replaced with a new filter layer directly. Thus, the service life of the respirator is extended. 
     It is a further object of the present invention to provide a complex respirator that includes a chamber therein for buffering pressure coming from air-breathing, so that people using this respirator can breathe smoothly and comfortably. 
     A complex respirator according to the present invention includes at least a first filter layer, a first shell, and a second filter layer. The first shell is disposed on inner side of the first filter layer while the second filter layer is arranged on the inner side of the first shell. The material of the first filter layer can be changed according to the user&#39;s needs. The first filter layer has a larger pore size than that of the second filter layer, while the second filter layer has a larger area than that of the first filter layer. An air chamber is formed between the second filter layer and the first shell so as to make air inhaled or exhaled flow through the first filter layer and the second filter layer uniformly. The present invention further includes a second shell arranged on outer side of the first filter layer for preventing the first filter layer from exposure to water. Moreover, the second shell and the first shell together form an open space facing downwards allowing the inhaled or external air to flow therethrough. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
         FIG. 1  is schematic drawing showing fiber of conventional flat respirators; 
         FIG. 2  is schematic drawing showing a traditional respirator with a cartridge; 
         FIG. 3  is a schematic drawing of an embodiment according to the present invention; 
         FIG. 4A  is a schematic drawing showing air flow of an embodiment according to the present invention; 
         FIG. 4B  is a schematic drawing showing air flow of an embodiment according to the present invention; 
         FIG. 5A  is a schematic drawing showing filter layers of another embodiment according to the present invention; 
         FIG. 5B  is a schematic drawing showing filter layers of another embodiment according to the present invention; 
         FIG. 6  is a schematic drawing showing structure of a further embodiment according to the present invention; 
         FIG. 7  is a schematic drawing showing structure of a further embodiment according to the present invention; 
         FIG. 8A  is a schematic drawing showing the replacement of the filter layer; 
         FIG. 8B  is a schematic drawing showing structure of a further embodiment according to the present invention; 
         FIG. 9A  is a schematic drawing showing air flow of a further embodiment according to the present invention; 
         FIG. 9B  is a schematic drawing showing air flow of a further embodiment according to the present invention; 
         FIG. 10  is a schematic drawing showing structure of a further embodiment according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIG. 3 , a complex respirator  30  according to the present invention consists of a first shell  32 , at least a first filter layer  34  and a second filter layer  36 . The first filter layer  34  is disposed on an outer side of the first shell  32  and a plurality of first air holes  322  is arranged in a central (that is, non-peripheral) portion of the first shell  32  corresponding to the position of the first filter layer  34 . The second filter layer  36  is disposed on an inner side of the first shell  32 . The second filter layer  36  is made of a material with smaller pore diameter than that of the material of the first filter layer  34 . The first filter layer  34  is used to filter organic gas or microorganisms in the air while the second filter layer  36  is for filtering air with material that can&#39;t be filtered by the first filter layer  34  such as dust. The first shell  32  is made from a material impermeable to gas, so that the gas intake or exhaust can only passes through the first filter layer  34  and the second filter layer  36  via the first air holes  322 . 
     The filter area of the first filter layer  34  is smaller than that of the second filter layer  36 . The first filter layer  34  includes at least a layer of a first filter and a plurality of first microgranular filter media. The first microgranular filter media is distributed uniformly in a plane and is disposed in combination with the first filter, with a mixture setting so that gas passes through the first filter layer  34  uniformly. The second filter layer  36  consists of at least a layer of a second filter and a plurality of second microgranular filter media. The second microgranular filter media is distributed evenly in a plane and is disposed in combination with the second filter, with a mixture setting so that gas passes through the second filter layer  36  uniformly. An air chamber is formed between the second filter layer  36  and the first shell  32  so that intake gas through the first filter layer  34  and the exhaust gas pass the second filter layer  36  uniformly. 
     Refer to  FIG. 4A , there is shown use a complex respirator  30  according to the present invention to inhale air from outside. Because the first shell  32  is made from a gas impermeable material, outside air can&#39;t flow through the first shell  32  and is only able to pass through the first filter layer  34 . Then the air passes through the second filter layer  36  uniformly. As shown in  FIG. 4B , air exhausted through the complex respirator  30  according to the present invention diffuses uniformly through the second filter layer  36 . Yet the gas through the second filter layer  36  can&#39;t flow through the first shell  32 , it can only pass through the first filter layer  34 . Thus, the air inhaled and the air exhausted only pass through the first filter layer  34  and the second filter layer  36 . Therefore, the efficiency of the complex respirator  30  for filtering gas is improved. 
     As shown in  FIG. 5A  &amp;  FIG. 5B , the first filter layer  34  includes a plurality of layers of first filter  342 ,  344 ,  346  and a plurality of layers of first microgranular filter media  348 ,  350  while the second filter layer  36  includes a plurality of layers of second filter  362 ,  364 ,  366  and a plurality of layers of second microgranular filter media  368 ,  370 . Both the first microgranular filter media layers  348 ,  350  and the second microgranular filter media layers  368 ,  370  have a plurality of microgranular filter media so as to make gas impassable along fixed paths through the first filter layer  34  and the second filter layer  36 , respectively. Also, by means of a chamber located between the second filter layer  36  and the first shell  32 , gas inhaled or exhaled diffuses uniformly through the second filter layer  36 . Thus, the lifetime of the first filter layer  34  as well as the second filter layer  36  of the complex respirator  30 , of the present invention, is extended. 
     Referring to  FIG. 3 , a chamber between the second filter layer  36  and the first shell  34  provides a buffering space for pressure from gas so that people don&#39;t need to breath hard to get air in while breathing, and pressure coming from breathing won&#39;t cause deformation of the complex respirator  30 . While wearing the respirator  30 , breathing won&#39;t become difficult. 
     Moreover, the complex respirator  30  further includes a first fixing member  40  and a second fixing member  42 . The first fixing member  40  is disposed on edge of the first shell  32  for fixing a user&#39;s mouth and nose inside the covering area of the first shell  32 . The second fixing member  42  includes two circular threads, respectively connected with right and left sides of the first fixing member  40  for preventing the complex respirator  30  of the present invention from falling or loosening from the face of the user. Therefore, the complex respirator  30  according to the present invention goes over the nose and mouth completely without a gap between the respirator and the face of a user, so as to prevent dirty air flowing into the inner space covered by the first shell  32 . 
     The complex respirator  30  according to the present invention totally separates the nose and mouse from air outside and buffers pressure generated during breathing by the air chamber. Thus people are able to make use the complex respirator  30  to obtain clean air easily and breathe comfortably. 
     Refer to  FIG. 6 , the difference between the embodiment in this figure and the embodiment in  FIG. 3  is that in  FIG. 3 , a plurality of first air holes  322  is arranged on the first shell  32  corresponding to the position of the first filter layer  34 , while in  FIG. 6 , a first air vent  522  is disposed on the first shell  52  corresponding to the position of the first filter layer  54 . Moreover, the first filter layer  54  and the second filter layer  56  both include a plurality of layers of a beehive filter and a plurality of layers of an anti-bacteria, bacteriostatic and deodorization layer. The beehive filter consists of a plenty of beehive cells and each of the beehive cells is contains a microgranular filter media therein. A complex respirator  50  according to the present invention includes the first vent  522  arranged on the first shell  52  so that air inhaled and exhaled air pass through the large area of first filter layer  54 . 
     In this embodiment, the first filter layer  54  is composed of three layers of first beehive filter  542 ,  544 ,  546  and two layers of first bacteriostatic and deodorization layer  548 ,  550 , that are made from bacteriostatic and deodorization fiber material. The second filter layer  56  consists of three layers of second beehive filter  562 ,  564 ,  566  and two layers of second bacteriostatic and deodorization layer  568 ,  570 , that are made from bacteriostatic and deodorization fiber material. When air flows through the first filter layer  54  and the second filter layer  56 , it can&#39;t pass in a fixed path due to the beehive filter. By means of an air chamber formed between the second filter layer  56  and the first shell  52 , air inhaled or exhaled through the complex respirator  50  passes uniformly through the first filter layer  54  as well as the second filter layer  56 . The lifetime of the filter layer  54  and the second filter layer of the complex respirator  50  according to the present invention is extended. 
     Furthermore, when the first filter layer  54  can&#39;t filter the air continuingly, it can be replaced by another new piece of the first filter layer  54  that had not been used yet. Thus the complex respirator  50  according to the present invention reduces the amount of garbage from respirators. Because the first filter layer  54  is replaceable, users can choose the first filter layer  54  from those made from various materials depending on the place they intend to go. For example, if the destination is hospital, the first filter layer  54  chosen would be made from anti-bacteria or bactericidal material. If the place is a construction site, the first filter layer  54  chosen would be a material for filtering dust. If the place is a chemical factory, the first filter layer  54  chosen would be made from material that filter chemicals. 
     Refer to  FIG. 7 , the difference between the embodiment in  FIG. 7  and the embodiment in  FIG. 3  is that the embodiment in this figure includes a first shell  72  that connects with a cap  74  having air holes  742  for fixing a first filter layer  76  on the first shell  72  and a second shell  84  for protecting the first filter layer  76  from being exposed to drops of water. The cap  74  and the second shell  84  are arranged on the outer side of the first shell  72 . The top side, and edges on right and left sides of the second shell  84  connect with the first shell  72  so as to form an open space having an opening facing downwards. Thus, air passes in and out through the opening of the open space without separation of the second shell  84 . The second shell  84  is also made from impermeable material so that water drops can&#39;t pass. Thus the deformation or malfunction of microgranular filter media caused by influence of the water drops is avoided. 
     The first filter layer  76  is fixed in a slot  722  of the first shell  72  by the cap  74  that is arranged on the outer side of the slot  722 , corresponding to the opening of the open space for convenience of replacing the used first filter layer  76 . As shown in  FIG. 8A , when the first filter layer  76  no longer filters the air inhaled or exhaled, the cap  74  is opened for replacing the first filter layer  76  with a new first filter layer  86  that has not been used yet. After the new first filter layer  86  is disposed inside the slot  722  of the first shell  72 , the cap  74  secures the first filter layer  86 , as shown in  FIG. 8B . 
     Refer to  FIG. 9A , while people using the complex respirator  70  of the present invention to inhale air, air outside firstly flows into the open space that has on opening facing downwards and is located between the first shell  72  and the second shell  84 , because the first shell  72  is impermeable and air can&#39;t pass through it. Then, the air passes through the first filter layer  76 . Next, the air passes through and diffuses uniformly through the second filter layer  78 . Referring to  FIG. 9B , when people use the complex respirator  70  of the present invention to exhale air, the exhausted air diffuses through the second filter layer  78  uniformly. However, the air that has passed therethrough can&#39;t flow through the first shell  72 . Instead, it can only pass through the first filter layer  76  into the open space and flow out through the opening thereof facing downwards. Therefore, the second shell  84  has no influence on the breathing of users. 
     Refer to  FIG. 10 , the difference between the embodiment in  FIG. 3  ( 7 ) and the embodiment in  FIG. 10  is that the first filter layer  76  of the embodiment in the  FIG. 3  ( 7 ) includes three layers of the first filter  762 ,  764 ,  766 , while a first filter layer  96  of the embodiment in the  FIG. 10  includes three layers of a positioning plate  962 ,  964 ,  966 . A complex respirator  90  of the present invention fixes two layers of the first microgranular filter media  968 ,  970  by means of the three layers of the positioning plate  962 ,  964 ,  966 . The two layers of the first microgranular filter media  968 ,  970  are arranged between two of the three layers of positioning plate  962 ,  964 ,  966  to form two spaces for air flow so that the flow path of the air inhaled or exhaled is not fixed. By means of an air chamber between a first filter layer  96  and a second filter layer  98 , the complex respirator  90  causes air to uniformly pass through the first filter layer  96  as well as the second filter layer  98 . Thus, the lifetime of the first filter layer  96 , as well as the second filter layer  98 , of the complex respirator  90  is extended. 
     In addition, a complex respirator is not only for healthy people but also for patients. Patients who use such respirators can prevent droplet-transmitted bacteria or viruses from spreading to neighboring areas. The second filter layer made from bactericidal or anti-bacteria filter material filters bacteria or viruses to prevent infections such as flu or Severe Acute Respiratory Syndrome (SARS) from spreading rapidly. 
     In summary, the present invention provides a complex respirator that includes a first shell, a second shell, at least a first filter layer and a second filter layer. The first shell is disposed on inner side of the first filter layer while the second filter layer is arranged on inner side of the first shell. A slot is formed between the first shell and the second filter layer. The first filter layer is arranged in the slot and the second filter layer is set on inner side of the first shell. The air inhaled firstly passes through the first filter layer and then through the second filter layer. While the air exhaled flows through the second filter layer and then through the first filter layer. For the inhaled air, the first filter layer is for filtering particles of dust and the second filter layer is for filtering granules of a smaller diameter. As to the exhaled air, the second filter layer filters bacteria or other impurities. Use of the complex respirator by healthy people avoids the inhalation of toxic gas or harmful granules. If patients use the complex respirators, the respirator prevents micro-organisms carried by patients from spreading to surrounding areas. 
     Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Technology Classification (CPC): 0