Patent Publication Number: US-6705940-B1

Title: Portable doorway bug deflector

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to the general art of static structures, and to the particular field of protecting openings through walls of static structures. 
     2. Discussion of the Related Art 
     Many people like to leave the doors of their homes open especially during mild weather. However, when a door is open, insects and debris often migrate through the open doorway and into the interior of the home. This is an unacceptable situation, especially in view of the many diseases that insects have been known to carry. Still further, even if a door is closed, if it is opened even briefly to allow someone to pass into or out of a building, that opening, no matter how brief, tends to permit insects and debris to migrate into the interior of the building. In some instances, due to temperature differences between the interior of the building and the exterior of the building, there actually is a pressure difference which tends to draw such unwanted items into the interior of the building. Thus, even if a building has a screen door or a storm door, opening that door may expose the interior of the building to invasion of insects or debris or other such unwanted elements. 
     Therefore, there is need for a system that will prevent movement of insects, debris or other such elements into the interior of a building through an open doorway. Still further, there is a need for such a system that will operate to protect the interior of a building even if a door is opened only very briefly. 
     While the art contains disclosures of air curtains used in association with loading dock doors and the like, these air curtains do not adequately prevent migration of insects and debris through an open doorway especially if that doorway is only very briefly opened, or only slightly opened. 
     It may be wasteful to operate an air curtain on a continuous basis; however, in a loading dock situation, such continuous operation may be acceptable since the access opening may be in nearly continuous use. However, such a situation usually does not exist for a homeowner. 
     Therefore, there is a need for a system that will prevent movement of insects, debris and the like through a doorway and is activated only when the doorway is open and is inactive at all other times. 
     However, to be fully effective, such a system should be activated as soon as the doorway is open enough for such unwanted elements to move through the doorway. 
     Therefore, there is a need for a system that will prevent movement of insects, debris and the like through a doorway and that will be active only when the door is open and will be inactive when the door is closed, but will be activated as soon as the door is open enough to permit unwanted elements to move through the doorway. 
     As is well known, if there is any possible path into a building, insects will find such a path. Therefore, in order to be fully effective, any system which is intended to prevent migration of insects, debris or the like into the interior of a building via an open door must protect essentially the entire doorway. 
     Therefore, there is a need for a system that will prevent the migration of insects, debris or the like into the interior of a building through an open door and which protects essentially the entire area of the doorway, from the bottom to the top and from one side of the doorway to the other side of the doorway. 
     PRINCIPAL OBJECTS OF THE INVENTION 
     It is a main object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door. 
     It is another object of the present invention to provide a system for forming a protective air layer across an access doorway of a building It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which will be activated as soon as the door is opened and will be inactive at other times. 
     It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which is oriented to provide a stream of air flowing in an outward direction with respect to the building interior. 
     It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which is oriented to provide a stream of air flowing in an outward direction with respect to the building interior and in which the air flows at an oblique angle with respect to a plane containing the doorway. 
     It is another object of the present invention to provide a system for preventing unwanted elements, such as insects, debris or the like, from moving into a building through an open door and which is oriented to provide a stream of air flowing in an outward direction with respect to the building interior and which protects essentially the entire length dimension of the doorway. 
     SUMMARY OF THE INVENTION 
     These, and other, objects are achieved by a system for forming a protective air layer across an access doorway of a building comprising a wall of a building, the wall having an interior side inside the building and an exterior side and extending upwardly from a ground level; a doorway defined through the wall, said doorway having a length dimension and a width dimension, with the length dimension extending upwardly from the ground level, the doorway being contained in a plane; a jamb on the wall around the doorway; a door moveably mounted on the jamb to move between a closed position and an open position; a fan unit mounted on the jamb adjacent to the doorway, the fan unit including a motor unit mounted on the jamb adjacent to the doorway, two fan housings mounted on the jamb adjacent to the doorway and extending upwardly from the ground level, each fan housing including an intake side, a plurality of vents, each vent of the plurality of vents being oriented at an oblique angle with respect to the plane containing the doorway and directed away from the interior side of the wall, a rotor mounted inside each fan housing, and a plurality of arcuate rotor blades mounted on the rotor of each housing and oriented to draw air from the intake side of the housing associated therewith and move the air to the vents of the plurality of vents of the housing associated therewith; and a circuit which includes a switch mounted on the jamb to be held in an open position when the door is in the closed position and to move into a closed position when the door is moved into the open position, a power source electrically connected to the switch to be connected to the motor when the switch is in the closed position, the motor being activated and rotating the rotor blades when connected to the power source; the fan unit extending for essentially the entire length dimension of the doorway. Air flowing out of the vents of the plurality of vents moves at an oblique angle across the doorway with respect to the plane containing the doorway, with the plane containing the doorway being located between the air flowing out of the vents and the plane containing the doorway and between the exterior side of the wall and the interior side of the wall. 
     Thus, every time the door is opened, a curtain of air is set up across the doorway and is directed outwardly of the building. Any debris or insects will thus be blown outwardly with respect to the building each time the door is opened. This will protect the building against such unwanted intruders. Even if the door is only slightly cracked open, the curtain of air will be set up and the doorway will thus be protected. The air is directed at an oblique angle with respect to the plane containing the doorway and thus will blow outwardly with respect to the building thereby not only protecting the doorway but also tending to clean out the area adjacent to the doorway. Since the fan housings extend for the entire length dimension of the doorway, the air flowing out of the vents will cover the entire area of the doorway and thus will protect the entire area of the doorway. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 shows a door and doorway which includes the system embodying the present invention. 
     FIG. 2 shows the fan housings of the present invention in place adjacent to the doorway. 
     FIG. 3 is a perspective view of a fan housing and some circuitry associated therewith. 
     FIG. 4 is a top plan view of a fan housing of the fan unit included in the system embodying the present invention along with a top plan view of a plurality of arcuate rotor blades included in the fan unit included in the system embodying the present invention. 
     FIG. 5 is a perspective view of a rotor unit included in the fan unit of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Other objects, features and advantages of the invention will become apparent from a consideration of the following detailed description and the accompanying drawings. 
     As shown in the figures, the present invention is embodied in a system  10  for forming a protective air layer  12  across an access doorway  14  of a building  16 . 
     A wall  18  of building  16  has an interior side  20  inside the building and an exterior side  22  outside the building  16 . A doorway  24  is defined through the wall  18  and traffic passes through the doorway  24  into and out of the building  16 . A jamb  26  is located on the wall  18  around the doorway  24 . Jamb  26  includes a first side  28 , a second side  30 , and a width dimension  32  measured between the first side  28  and the second side  30  of the jamb  26 . Jamb  26  further includes a first end  34 , a second end  36 , and a length dimension  38  measured between the first end  34  and the second end  36  of the jamb  26 . 
     Hinges, such as hinge  40 , are mounted on the first side  28  of the jamb  26 . A door  42  is mounted in the doorway  24  on the hinges  40 . Door  42  includes a first side  44  adjacent to the first side  28  of the jamb  26 , a second side  46 , and a width dimension  48  extending between the first side  44  of the door  42  and the second side  46  of the door  42 . Door  42  further includes a first end  50  adjacent to the first side  28  of the jamb  26 , a second end  52  adjacent to the second end  36  of the jamb  26 , and a length dimension  54  extending between the first end  50  of the door  42  and the second end  52  of the door  42 . 
     The door  42  is movable between a closed condition as shown in FIG. 1 extending over the opening  24  in the wall  18  and having the second side  46  of the door  42  adjacent to the second side  30  of the jamb  26  and an open condition having the second side  30  of the door  42  spaced apart from the second side  30  of the jamb  26 . For the purposes of this disclosure, the door  42  is considered as being in the open position when the second side  46  of the door  42  is spaced apart from the second side  30  of the jamb  26  by as small as ¾ inch. 
     A fan unit  60  is mounted on the second side  30  of the jamb  26 . The fan unit  60  includes two fan housings  62  and  64 . The fan housings  62 ,  64  are identical to each other. Each fan housing  62 ,  64  includes a first end  66 , a second end  68 , and a length dimension  70  extending between the first end  66  of each fan housing  62 ,  64  and the second end  68  of each fan housing  62 ,  64 . The length dimensions  70  of the fan housings  62 ,  64  are aligned with each other and with the length dimension  38  of the door jamb  26 . Each fan housing  62 ,  64  includes a first side  72  which extends between the first end  66  of the fan housing  62 ,  64  and the second end  68  of the fan housing  62 ,  64 . The first side  72  of each fan housing  62 ,  64  is fixed to the wall  18  adjacent to the second side  30  of the jamb  26 . A second side  74  of the fan housing  62 ,  64  extends between the first end  66  of the fan housing  62 ,  64  and the second end  68  of the fan housing  62 ,  64 . The second side  74  of the fan housing  62 ,  64  is spaced apart from the first side  72  of the fan housing  62 ,  64 . An offset portion  78  of the second side  74  of the fan housing  62 ,  64  is offset from a remaining portion  80  of the second side  74  of the fan housing  62 ,  64  and is oriented at an oblique angle θ to the remaining portion  80  of the second side  74  of the fan housing  62 ,  64 . 
     Two side panels  82  and  84  connect the offset portion  78  of the second side  74  of the fan housing  62 ,  64  to the remainder of the second side  74  of the fan housing  62 ,  64 . 
     A plurality of air vents, such as air vent  90 , are defined through the offset portion  78  of the second side  74  of the fan housing  62 ,  64 . The air vents  90  are spaced apart from each other along the length dimension  70  of the fan housing  62 ,  64 . The air vents  90  are all oriented at oblique angle 0 with respect to the wall  18 . The air vents  90  are located adjacent to the exterior side  22  of the wall  18  with the wall  18  being located between the air vents  90  and the interior side  22  of the wall  18 . The air vents  90  are also located adjacent to the second side  30  of the jamb  26  to establish a flow of air across the door opening  24 . Being located adjacent to the second side  30  of the jamb  26  and having the fan housings  62 ,  64  extending for essentially the entire length  38  of the jamb  26  permits the system  10  to establish a wall of air across any opening that is defined in the doorway  24  as soon as the door  42  is opened. Thus, even if the door  42  is only slightly cracked open, the wall of air established by the air vents  90  will protect that opening  24  as soon as the door  42  is moved even slightly away from the jamb  26 . Thus, one source of entry into the building  16  by insects, debris or the like is immediately sealed off as soon as the door  42  is opened. The air flow direction is also outwardly of the opening  24  so any insects or debris that may be in the air adjacent to the door  42  when the door  42  is closed will be blown away from the doorway  24  as soon as the door  42  is opened. This actually clears the area adjacent to the doorway  24  in addition to simply preventing the unwanted elements from entering the building  16  via the doorway  24 . 
     An air intake  92  is located on the remaining portion  80  of the second side  74  of the fan housing  62 ,  64 . The air intake  92  is located and oriented to be in fluid communication with the air located inside the building  16 . Thus, when the system  10  of the present invention is activated, inside air is blown out and across any opening established in the doorway  24  as soon as that opening is established. If there is any temperature gradient or the like that may create a pressure gradient that tends to draw air from outside the building  16  into the building  16 , such air flow is opposed by the air wall established from the air vents  90  of the system  10  of the present invention. 
     A plurality of arcuate rotor blades, such as blade  100 , are located in each housing  62 ,  64  of the fan unit  60 . The rotor blades  100  are mounted on a rotor shaft  102  and are located between the intake  92  of the housing  62 ,  64  and the air vents  90  of the housing  62 ,  64  and are shaped as indicated in FIGS. 4 and 5 to move air from the intake  92  of the housing  62 ,  64  to the vents  90  of the housing  62 ,  64 . The rotor blades  100  extend along the length dimension  38  of the jamb  26 . 
     The two housings  62 ,  64  of the fan unit  60  are oriented with respect to each other so the length dimension  70  of one housing  62  or  64  is aligned with the length dimension  70  of the other housing  64  or  62 . 
     Air moving out of the air vents  90  flows at an oblique angle with respect to a plane containing the doorway  24  and moves across the doorway  24  so the doorway  24  is interposed between the air moving out of the air vents  90  and the interior side  20  of the wall  18 . 
     A motor  110  is mounted on the wall  18  between the two housings  62 ,  64 . The motor  110  includes an output shaft  112  connected to the rotor shaft  102  of each housing  62 ,  64  to rotate the rotor blades  100  in each housing  62 ,  64  when the motor  110  is activated. Motor  110  is a 1500 rpm motor in one form of the invention. 
     A control circuit  114  includes a switch  116  which can be a proximity switch such as shown in FIG. 2, or a normally closed switch that is held open by the door  42  when closed, or the like. The switch  116  is mounted on the door jamb  26  to be contacted by the second side  46  of the door  42  when the door  42  is in the closed condition in order to open the switch  116 . If a proximity switch is used, the proximity of the second side  46  of the door  42  to the switch  116  will be used to open the switch  116 . A power cord  118  connects the switch  116  to a power source  120 . An electric cord  122  connects the switch  116  to the motor  110 . The switch  116  is movable between an OFF condition and an ON condition. Power from the power source  120  is applied to the motor  110  when the switch  116  is in the ON position. 
     The combined length dimensions  70  of the two housings  62 ,  64  of the fan unit  60  and a length dimension of the motor  110  of the fan unit  60  is essentially equal to the length  38  of the doorway  24 . In this manner, the entire area of the doorway  24  is covered by the air flowing out of the air vents  90  to force insects, debris and the like away from the doorway  24  every time the door  42  is opened. The oblique angle directs the air flow to achieve this result and the fan housings  62 ,  64  extending for the entire length of the door protects the entire door area. 
     It is understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangements of parts described and shown.