Abstract:
A magnetic door sweep and magnetic threshold is disclosed which reliably aligns and seals to prevent water, air and pests from crossing the threshold of a door. Additionally, the magnetic door sweep and magnetic threshold will prevent shape loss of the door sweep. The magnetic door seal includes a primary seal and a door seal magnetic element having a first set of poles located on the bottom edge of a door. A magnetic threshold includes a threshold cap and a threshold magnetic element having a second set of poles. The door seal is positionable relative to the threshold as the door is closed such that the first set of poles is attracted to the second set of poles when said door seal is positioned proximate to the threshold allowing the primary seal to extend between the door and the threshold.

Description:
FIELD OF THE INVENTION 
     The present invention relates to door sweeps and door thresholds. More specifically, the invention relates to a magnetic door sweep and a magnetic threshold whose magnets have specifically arranged polarities to create a controlled magnetic seal between the door sweep and the threshold. 
     BACKGROUND OF THE INVENTION 
     The major parts of a door sealing system consist of a door sweep, which is located at the bottom of most entry doors to assist in sealing the bottom of the door, and a threshold cap, which makes contact with the door sweep to seal and help prevent water, air and pests from passing beyond the threshold. While current door sealing systems have generally proven to be satisfactory for their applications, each is associated with its share of limitations. 
     One major limitation of many current door sealing systems relates to their inability to consistently form a consistent seal due to variation between the door and the threshold throughout the life of the door seal. Due to current designs, door sweeps become deformed, lose their shape and ultimately leave gaps in the seal thus compromising the integrity of the entire seal. This permits water, air and pests to pass beyond the threshold. 
     Another limitation of many known door sweeps is the harsh noise created by the door sweep and threshold when the doors are opened or closed. The noise is caused by the door sweep being dragged across the threshold. Additionally, this noise may be made worse by thresholds that have a grooved surface. However, door sweeps that contact thresholds upon opening have traditionally been necessary to create and maintain a seal between the door and its corresponding threshold. 
     Another limitation of current door sweeps and their associated thresholds is their propensity to wear through due to constant scuffing of the door sweep on the threshold. This creates a need for maintenance and as the door sweep wears, its sealing effectiveness generally diminishes. 
     What is needed then is a device that does not suffer from the above limitations. This in turn, will provide a device that repeatedly creates a proper seal between the door sweep and its associated threshold every time the door is opened and closed, regardless of which direction the door is opened or closed. Furthermore, a door sweep device will be provided that does not lose its shape after repeated door openings and closings. Additionally, a door sweep and its associated threshold is needed that does not make harsh noises upon every opening and closing of an associated door. Finally, a door sweep is needed that does not wear out or at least is capable of experiencing a longer life than current door sweeps. It is, therefore, an object of the present invention to provide a door sweep and threshold that achieves the above-identified advantages. 
     SUMMARY OF THE INVENTION 
     In accordance with the teachings of the present invention, a magnetic door sweep and magnetic threshold are provided that reliably align and seal to prevent water, air and pests from crossing the threshold of a door. Additionally, the magnetic door sweep and magnetic threshold will prevent shape loss of the door sweep. The magnetic door seal includes with a primary seal and a door seal magnetic element having a first set of poles located on the bottom edge of a door. A magnetic threshold includes a threshold cap and a threshold magnetic element having a second set of poles. The door seal is positionable relative to the threshold as the door is closed such that the first set of pole are attracted to the second set of poles when said door seal is positioned proximate to the threshold allowing the primary seal to extend between the door and the threshold. 
     Continuing with advantages, the magnetic door sweep and magnetic threshold will prevent dragging of the door sweep across the threshold which will, in turn, prevent undesirable noise from emanating from the door sweep area and prevent abrasive wearing of the sweep jacket, which will prolong the life of the sweep jacket. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a cross-sectional view of a door sweep and threshold showing the polar arrangements of a door sweep magnet and a door threshold magnet according to teachings of the present invention; 
         FIG. 2  is a cross-sectional view of a door sweep and threshold in a situation in which the door sweep is approaching the threshold according to teachings of the present invention; 
         FIG. 3  is a cross-sectional view of a door sweep and threshold in which the door sweep is at its maximum height over the threshold according to teachings of the present invention; 
         FIG. 4  is a cross-sectional view of a door sweep and threshold in which the door sweep is nearly in its final position over the threshold before sealing according to teachings of the present invention; and 
         FIG. 5  is a cross-sectional view of a door sweep and threshold in which the door sweep is in its sealed position over the threshold according to teachings of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  FIG. 1  depicts a cross-sectional view of a magnetic door sweep and a magnetic threshold  10  according to teachings of the present invention. The magnetic door sweep and magnetic threshold  10  has a magnetic door sweep  20  and a magnetic threshold  50 . Turning to the magnetic door sweep  20 , a door  22  has a door sweep base plate  28  attached along a bottom edge thereof. The door  22  has an inside surface  24  and an outside surface  26 , which respectively represent the inside of a building and an outside of a building. Attached to the door sweep base plate  28  is a door seal  30 , which has a flexible bellows  32  attached to a magnet  34 . As presently preferred, magnet  34  is a bar magnet having a north pole “N” along one longitudinal edge and a south pole “S” along opposite longitudinal edge. The magnet  34  may be covered with a jacket  36  that is made of a material that is suitable for sealing such as rubber or plastic. 
     In addition to the door seal  30 , the magnetic door sweep  20  has an inside sweep seal  38  and an outside sweep seal  40 . These seals  38 ,  40  provide aesthetic appeal since they shield the door seal  30  from the view of door users and they act as an additional level of sealing from wind, water, pests, etc. Since the inside sweep seal  38  and the outside sweep seal  40  may minimally touch the threshold cap  52 , or reach to just above the threshold cap  52 , they are effective in their purpose of sealing and providing aesthetic value to the magnetic door sweep and magnetic threshold  10 . Attached to the outside portion of the door sweep base plate  28  is a base plate shield  42 , which is provided for aesthetic qualities as it blocks the view of the door seal  30 . 
     With continued reference to  FIG. 1 , the magnetic threshold  50  will be explained. The magnetic threshold  50  has a threshold cap  52  and a magnet  54  that is attached within the interior volume  56  of threshold cap  52  by an adhesive or mechanical fastener such as a screw. Alternately, the threshold cap  52  may have an interior support formed within the interior volume thereof to support the magnet  54 . As presently preferred, magnet  54  is a bar magnet having a north pole “N” and a south pole “S” which are positioned in an opposite orientation relative to the poles of magnet  34 . The width between the poles of magnet  54  is greater than the width between the poles of magnet  34 . In this way, magnet  34  and the door seal  30  is generally centered over the magnet  54  in the threshold  50 . Thus, a positive seal between the door  22  and the threshold  52  can be assured. The threshold cap  52  is supported by a door plate  58  and a door sill  60 . The door plate  58  is located on the outside of a building and is typically aluminum but can be made of a ferrous metal, wood or other material capable of withstanding the repeated weight of door users. The door sill  60  is typically wood, but can be made of plastic or other material capable of withstanding the repeated weight of door users. The door sill  60  provides added support to the door plate  58  and threshold cap  52 . 
     With continued reference to  FIG. 1 , the sealing of the magnetic door sweep and magnetic threshold  10 , when the door  22  is in its closed and sealed position, will be explained. In this closed position, a magnetic seal is created because of the opposed positioning of the polarities of the magnets  34 ,  54  when the door is in its closed position. As can be seen in  FIG. 1 , the north pole “N” of the top magnet  34  is proximate to and attracted to the south pole “S” of the bottom magnet  54 . Additionally, the south pole “S” of the top magnet  34  is attracted to the north pole “N” of the bottom magnet  54 . Between the north pole “N” and the south pole “S” of the top magnet, exists a transitional range of polarity strength from the north pole to the south pole. That is, as the distance from the north pole to the south pole increases, the strength of the north pole decreases and the strength of the south pole increases. 
     With respect to the top magnet  34 , the maximum strength of the north pole “N” is at the inside edge of the top magnet  34 , that is, at the outside side of the bellows  32 , while the maximum strength of the south pole “S” is at the outside edge of the top magnet  34 , that is, at the inside side of the bellows  32 . The inside side and outside side of the bellows  32  is equivalent to the inside surface  24  of the door  22  and the outside surface  26  of the door  22 . The same relationship is true of the bottom magnet  54 , although the maximum strength of the south pole “S” is at the outside edge of the bottom magnet  54  and the maximum strength of the north pole “N” is at the inside edge of the bottom magnet  54 . The inside seal  38  and the outside seal  40  generally do not move during the opening and closing of the door  22 . The seals  38 ,  40  provide an extra level of protection at the bottom of the door  22  against airflow. They also provide aesthetic aspect to the magnetic door sweep and magnetic threshold  10  by shielding the magnetic door sweep and magnetic threshold  10  from the view of door users. 
     With reference to  FIGS. 2 through 5 , the process of sealing when the door moves from an open position to its closed and sealed position, will be explained.  FIG. 2  is a cross-sectional view of a magnetic door sweep  20  and a magnetic threshold  50  in a situation in which the door  22  is closing and the door seal  30  is approaching the magnetic threshold  50  according to teachings of the present invention. With reference to  FIG. 2 , the magnetic door sweep  20  moves in the direction of arrow  62  toward its closed position. The closed position of the door  22  and its associated door seal  30  occurs when the magnetic door sweep  20  is directly above the magnetic threshold  50 , as seen in  FIG. 1 . Continuing with reference to  FIG. 2 , as the magnetic door sweep threshold  20  moves, the door seal  30  with its top magnet  34  is still in a retracted position due to the memory of the bellows  32 . That is, the top magnet is unaffected by the magnetic force of the bottom magnet  54  of the magnetic threshold  50 . The retracted position of the door sweep  30 , and more specifically, the flexible bellows  32  and top magnet  34 , is in its natural suspension position when it is unaffected by any magnetic forces.  FIG. 2  shows such a position. 
       FIG. 3  is a cross-sectional view of a magnetic door sweep  20  and a magnetic threshold  50  in which the door seal  30  is at its maximum height over the magnetic threshold  50  according to teachings of the present invention. As the magnetic door sweep  20  approaches the magnetic threshold  50  according to the direction of motion noted by arrow  62 , the door seal  30  is pushed upwardly from the repelling force of the north pole “N” of the top magnet  34  when located directly over or proximate to the north pole “N” of the bottom magnet  54 . This repelling force causes the flexible bellows  32  of the door seal  30  to contract in the direction noted by arrow  64 . When the door seal  30  contracts, the jacket  36  surrounding the top magnet  34  does not contact the threshold cap  52 , which provides several advantages. The advantages of the jacket  36  not contacting the threshold cap  52  is that there is no noise generated, which normally occurs when a door sweep contacts or is dragged across a threshold, and there is no wearing of the jacket  36 , which normally occurs when the jacket  36  would otherwise contact the threshold cap  52 . The contraction of the bellows  32  and lifting of the door seal  30  above the threshold cap  52  continues as the magnetic door seal  30  moves over the magnetic threshold  50 . 
       FIG. 4  is a cross-sectional view of a magnetic door seal  30  and a magnetic threshold  50  in which the door seal  30  is approaching its sealing position over the threshold cap  52  and bottom magnet  54  according to teachings of the present invention.  FIG. 4  depicts a situation in which the magnetic door seal  30  continues moving in the direction of arrow  60 . As the magnetic door seal  30  continues to move, the position of the top magnet  34  is different than it was in  FIG. 3 , with respect to the bottom magnet  54 . In  FIG. 4 , the top magnet  34  is closer to its sealing position. This means that the door seal  30  has begun its decent toward the threshold cap  52 . This is caused by the changing attraction between the top and bottom magnets  34 ,  54 . 
     In  FIG. 4 , the north pole “N” of the top magnet  34  is approaching or proximate to the south pole “S” of the bottom magnet  54 , and the south pole “S”of the top magnet  34  is approaching or proximate to the north pole “N” of the bottom magnet  54 . The locations of the magnets  34 ,  54  in  FIG. 4  create a magnetic attraction force between the magnets  34 ,  54 . Therefore, the door seal  30  begins moving in the direction of arrow  66  causing the bellows  32  to begin to open, expand or reach toward the threshold cap  52 . At the same time, the magnetic door seal  30  continues to move in the direction of arrow  62 , which causes an increase in the attraction forces due to continued alignment and positioning of the magnetic polarities. 
       FIG. 5  is a cross-sectional view of a magnetic door seal  30  and a magnetic threshold  50  in which the door seal  30  is in its sealed position on the threshold cap  52  according to teachings of the present invention. At the position shown when the door seal  30  is on the threshold cap  52 , the jacket  36  on the top magnet  34  contacts the threshold cap  52 . In this position, the bellows  32  is fully extended in the direction noted by arrow  66 . Additionally, the distance between the corner north pole “N” of top magnet  34  and the corner south pole “S” of the bottom magnet  54  is equal to or nearly equal to the distance between the corner south pole “S” of the top magnet  34  and the corner north pole “N” of the bottom magnet  54 . Thus, the magnet  34  and hence the door seal  30  is generally centered over the magnet  54  and threshold cap  52 . 
     The magnetic attraction created by the specific positioning of the polarities of the magnets  34 ,  54  creates a magnetic attraction between the top magnet  34  and bottom magnet  54  that seals the jacket  36  of the door seal  30  to the top surface of the threshold cap  52 . Since the contact seal of the jacket  36  and the top surface of the threshold cap  52  does not occur until the above-explained positioning of magnetic polarities occurs, there is no other contact between any of the parts. Because of this, there is no noise associated with the door seal  30  and threshold cap  52  upon closing the door. Additionally, because there is no dragging contact before the jacket  36  seals with the threshold cap  52 , there is no associated wearing of the parts. The door seal  30  essentially reaches out to the threshold cap  52  when the desired magnetic polarity alignment has occurred, and causes a head-on magnetic contact between the top magnet  34 , which is surrounded by the jacket  36 , and the bottom magnet  54 , which is covered by the threshold cap  52 . 
     Upon opening of the door, the magnetic door sweep  20  works in a generally reverse order to that described above. The magnet force holding the door seal  30  against the threshold cap  52  is overcome by the opening force of the door  22 . As the magnet  34  moves relative to the magnet  54 , the polarity of the magnets  34 ,  54  causes the seal to be urged away from the threshold  50 , thereby unsealing the door  22  from the threshold  50 . 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. For example, the preferred embodiment is described as having a set of bar magnets. However, one skilled in the art will recognize that other magnetic elements may be employed in the present invention. In this regard, discrete magnet elements could be incorporated into the threshold cap in place of the singular bar magnet. Such variations are not to be regarded as a departure from the spirit and scope of the invention.