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You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to door seals and, more particularly, to a door seal system having a pneumatic seal that automatically inflates and deflates when a door is closed or opened, respectively.  
         [0002]     There must be a gap between a door and its doorframe in order for the door to open and close efficiently. A door seal, however, is usually installed upon an inner surface of the door frame for sealing out air, dust, sound, light, insects, etc. Having a good door seal contributes to energy efficiency and savings on heating and cooling costs.  
         [0003]     Various types of door seals have been proposed in the art. Although assumably effective, traditional door seals are not able to completely conform to the gap between a door and a frame, especially where the gaps are irregular or change over time. Further, having very thick door seals to completely fill all gaps makes opening and closing doors too difficult.  
         [0004]     Therefore, it would be desirable to have a door sealing system that includes a pneumatic liner for completely filling the gap between the door and the frame. Further, it would be desirable to have a door sealing system that automatically inflates when a door is closed and automatically deflates when a door is opened.  
       SUMMARY OF THE INVENTION  
       [0005]     Accordingly, a door sealing system according to the present invention includes a door frame and a pneumatic liner disposed along an inner perimeter of the frame for preventing air leakage between the frame and the door. The door sealing system includes a construction that may be adjusted between extended and retracted configurations. The system further includes a pump in communication with the liner for selectively filling the liner with air or other gaseous substance and includes a release valve for selectively the air therefrom. When the liner is expanded, it conforms to the space between the frame and door, even if the space is irregular. When the air is exhausted, the door is able to open easily.  
         [0006]     The door sealing system includes a sensor and a processor for controlling when the pump and valve are actuated to either inflate or deflate the pneumatic liner. In operation, the sensor senses when a latch is received into a cavity indicative of the door being closed. The processor, then, actuates the pump to inflate the liner. Conversely, when the latch is detected outside the cavity indicating the door is being opened, the valve is deactivated to allow the liner to be deflated.  
         [0007]     Therefore, a general object of the invention is to provide a door sealing system having a pneumatic liner mounted to an inner perimeter of a door frame.  
         [0008]     Another object of this invention is to provide a door sealing system, as aforesaid, in which the pneumatic liner may be selectively inflated and deflated.  
         [0009]     Still another object of this invention is to provide a door sealing system, as aforesaid, which includes a sensor for detecting if the door is opened or closed.  
         [0010]     Yet another object of this invention is to provide a door sealing system, as aforesaid, which actuates a pump to inflate the liner when the door is closed and deactivates a valve to deflate the liner when the door is opened.  
         [0011]     A further object of this invention is to provide a door sealing system, as aforesaid, having a proximity sensor capable of detecting a person approaching the door and deflating the liner accordingly.  
         [0012]     Other objects and advantages of the present invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, embodiments of this invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of a door sealing system according to the present invention;  
         [0014]      FIG. 2   a  is a front view of a door of the system as in  FIG. 1 ;  
         [0015]      FIG. 2   b  is a top view of the door as in  FIG. 2   a;    
         [0016]      FIG. 2   c  is an isolated portion on an enlarged scale taken from  FIG. 2   b;    
         [0017]      FIG. 3   a  is a front view of a pneumatic liner removed from the system as in  FIG. 1 ;  
         [0018]      FIG. 3   b  is a sectional view taken along line  3   b - 3   b  of  FIG. 3   a;    
         [0019]      FIG. 3   c  is an isolated view on an enlarged scale taken from  FIG. 3   b  with the liner in an extended configuration;  
         [0020]      FIG. 3   d  is an isolated view on an enlarged scale taken from  FIG. 3   b  with the liner in an retracted configuration;  
         [0021]      FIG. 4   a  is a front view of the system as in  FIG. 1 ;  
         [0022]      FIG. 4   b  is a sectional view taken along line  4   b - 4   b  of  FIG. 4   a;    
         [0023]      FIG. 4   c  is an isolated view on an enlarged scale taken from  FIG. 4   b  showing the door latch in the frame cavity;  
         [0024]      FIG. 4   d  is an isolated view on an enlarged scale taken from  FIG. 4   b  showing the door latch retracted from the frame cavity; and  
         [0025]      FIG. 5  is a block diagram showing the electronic components of the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0026]     A door sealing system  100  according to the present invention will now be described in detail with reference to  FIGS. 1 through 5  of the accompanying drawings. More particularly, a door sealing system  100  according to the current invention is for use with a door  10  and includes a frame  110  having an inner perimeter  112  sized to receive the door  10 .  
         [0027]     A pneumatic liner  120  is positioned along at least a portion of the frame inner perimeter  112  to selectively prevent leakage (e.g., passage of air) between the frame  110  and the door  10 . In various embodiments, the pneumatic liner  120  may be positioned along the entire frame inner perimeter  112  to encircle the door  10 . As shown in  FIGS. 3   c  and  3   d , the pneumatic liner  120  may have a hollow interior region  125  and be selectively adjustable between a retracted configuration  120   a  ( FIG. 3   d ) and an extended configuration  120   b  ( FIG. 3   c ). The liner  120  has an exterior mating surface  122  for contact with the door  10  and an exterior attachment surface  124  opposite the mating surface  122 . The exterior attachment surface  124  may be attached to the frame inner perimeter  112 . The pneumatic liner  120  may have parallel accordion pleats  126  ( FIGS. 3   c  and  3   d ) between the exterior attachment surface  124  and the exterior mating surface  122  to allow the pneumatic liner  120  to be selectively adjusted between the extended and retracted configurations  120   b ,  120   a . It is currently preferred that the pneumatic liner  120  be biased to the retracted configuration  120   a , as discussed below, though this need not be the case.  
         [0028]     As shown in  FIG. 4   c , the door  10  may have an exterior perimeter  12  with a configuration complementary to a configuration of the pneumatic liner exterior mating surface  122  when the pneumatic liner  120  is at the extended configuration  120   b . More particularly, a groove  14  may extend along the entire door exterior perimeter  12  ( FIG. 2   c ), and the groove  14  may be complementary to the pneumatic liner exterior mating surface  122  when the pneumatic liner is at the extended configuration  120   b . The frame inner perimeter  112  and the door exterior perimeter  12  may both have rounded corners  112   a ,  12   a  ( FIG. 1 ) so that the pneumatic liner  120  does not have to meet the door  10  or the frame  110  at a right angle, and the door  10  may be hingedly coupled to the frame  110  (e.g., by hinge  15 ).  
         [0029]     Means for selectively adjusting the pneumatic liner  120  between the retracted and extended configurations  120   a ,  120   b  are included. More particularly, a pump  132  (e.g., an air pump or compressor) may be in communication with the pneumatic liner hollow interior region  125  for selectively introducing a gaseous substance (e.g., air) into the hollow interior region  125  to adjust the pneumatic liner  120  to the extended configuration  120   b . It is understood that a portable, refillable air tank may also be used in place of or in cooperation with an air compressor. A valve  134  ( FIG. 5 ) may be in communication with the pneumatic liner hollow interior region  125  for selectively allowing the gaseous substance to exit the hollow interior region  125  to adjust the pneumatic liner  120  to the retracted configuration  120   a . The pump  132  may be incorporated in the frame  110 , or the pump  132  may be remote from the pneumatic liner  120  and connected to the pneumatic liner  120  by tubing  135  ( FIGS. 3   a  and  4   a ). It is currently preferred that the valve  134  be biased to allow the gaseous substance to exit the hollow interior region  125  when the valve  134  is not actuated, as discussed below, though this need not be the case.  
         [0030]     Means for actuating the pump  132  and the valve  134  are included. More particularly, according to one embodiment, the door  10  includes a latch  16  ( FIGS. 4   c  and  4   d ) that selectively extends outwardly, and the frame defines a cavity  116  positioned and sized to receive at least a portion of the latch  16  when the door  10  is positioned in the frame  110  and the latch  16  is extended. A sensor  142  ( FIG. 5 ) is included for determining whether the latch  16  is received in the cavity  116 , and a processor  144  is in data communication with the sensor  142 , the pump  132 , and the valve  134 . The processor  144  may only actuate the pump  132  when the latch  16  enters the cavity  116  and may only actuate the valve  134  as long as the latch  16  remains in the cavity  116 ; this collectively forces the pneumatic liner  120  to the extended configuration  120   b  when the latch  16  is in the cavity  116 . According to another embodiment, a plate  117  is coupled to the frame  110  adjacent the cavity  116 , and the sensor  142  is included for determining whether the latch  16  is adjacent the plate  117 . In this embodiment, the processor  144  may only actuate the pump  132  when the latch  16  becomes adjacent the plate  117  and may only actuate the valve  134  as long as the latch remains adjacent the plate  117 ; this collectively forces the pneumatic liner  120  to the extended configuration  120   b  when the latch  16  is adjacent the plate  117 .  
         [0031]     As shown in  FIG. 5 , at least one presence sensor  152  may be included to determine when someone is approaching the door  10 . As used herein, “presence sensor” refers to a sensor capable of detecting a person&#39;s presence (e.g., a proximity sensor or a motion sensor). The processor  144  may include programming for deactivating the valve  134  when the presence sensor  152  determines someone is approaching the door  10 .  
         [0032]     In use, the door  10  is coupled to the frame  110  (i.e., by hinge  15 ) so that the door  10  may selectively open and close. The sensor  142  may detect when the door  10  is received in the frame  110 , such as by detecting when the door latch  16  enters the frame cavity  116  or when the door latch  16  is adjacent the plate  117 . When the sensor  142  does detect that the door  10  is newly received in the frame  110 , the processor  144  may actuate the pump  132  and valve  134  as described above. The pump  132  may then pump the gaseous substance into the pneumatic liner hollow interior region  125 , and the valve  134  may keep the gaseous substance from exiting the liner  120 . As a result, the parallel accordion pleats  126  may be forced to extend, causing the pneumatic liner  120  to adjust to the extended configuration  120   b  ( FIG. 4   c ). Importantly, the pump  132  is deactivated (at the latest) when the pneumatic liner  120  reaches the extended configuration  120   b . When the liner  120  is at the extended configuration  120   b , the exterior mating surface  122  of the liner  120  may mate with the door groove  14  to effectively seal the area between the door  10  and the frame  110 . It may be difficult to open the door  10  when the pneumatic liner  120  is at the extended configuration  120   b . If the presence sensor  152  is included, the processor  144  may deactivate the valve  134  when the presence sensor  152  determines someone is approaching the door  10 . If the presence sensor  152  is not included, or if it does not appropriately detect someone&#39;s presence, the processor  144  may deactivate the valve  134  when the sensor  142  determines that the door latch  16  is not in the frame cavity  116  or that the door latch  16  is not adjacent the plate  117  ( FIG. 4   d ). When the valve  134  is deactivated, the gaseous substance may be allowed to escape the pneumatic liner interior region  125 , causing the pneumatic liner  120  to return to the retracted configuration  120   a . When the pneumatic liner  120  is at the retracted configuration  120   a , the door may be easily opened.  
         [0033]     In another embodiment, a carbon monoxide sensor (not shown) may be integrated into the frame  110  for providing an alarm when unacceptable levels of carbon monoxide are detected. The carbon monoxide sensor may be powered and actuated independently or may be wired directly into a larger security or ambient air detection system.  
         [0034]     It is understood that while certain forms of this invention have been illustrated and described, it is not limited thereto except insofar as such limitations are included in the following claims and allowable functional equivalents thereof.

Summary:
A door sealing system includes a frame and a pneumatic liner positioned along an inner perimeter of the frame. The liner includes a hollow interior for adjusting it between extended and retracted configurations. A pump is included for selectively inflating the liner and a valve which can be deactivated to deflate the liner. When inflated, the liner fills the gap between the door and the frame and when deflated, allows the door to be opened easily. A sensor is positioned with a cavity in the frame for detecting placement of a latch indicative of the door being opened or closed. A processor then appropriately actuates the pump or deactivates the valve. Accordingly, the seal is inflated when the door is closed and is deflated when the door is being opened.