Abstract:
An automatic door seal is provided for sealing the gap between the lower edge of a door and a threshold. The seal is magnetically actuated so as to move downward into sealing engagement with the threshold when the door is closed and raises out of engagement when the door is opened. A transmission assembly converts horizontal movement from the magnetic force into vertical movement for the seal. Springs provide a reset force when the magnetic force is eliminated so as to retract the seal strip whenever the door is moved from the closed position.

Description:
FIELD OF THE INVENTION 
       [0001]    The present utility model relates to the field of door accessories, particularly to a self-lifting sealing apparatus mounted at the bottom of the door. 
       BACKGROUND OF THE INVENTION 
       [0002]    Exterior doors often include seals to provide a substantially air tight and weatherproof barrier when the door is closed. There are generally two types of sealing apparatus, fixed and lifting, mounted at the bottom of a door. The fixed sealing strip maintains contact with the ground when opening/closing the door, and thus increases the resistance for the door, and affects how well the door closer operates. This fixed sealing strip is easily damaged. The lifting sealing apparatus is more complex. When the door opens, a sealing strip lifts off the threshold; when the door is closed to a predetermined position, the sealing strip descends to the threshold for sealing engagement, with a lifting seal, the resistance for opening/closing the door is decreased, thus facilitating the operation of the door closer. 
         [0003]    The lifting type sealing apparatus is usually equipped with a press mechanism which is mounted adjacent to the door hinge. When the door is closed, the door frame actuates the press mechanism, whereby a transmission mechanism is driven to descend the sealing strip. This lifting type sealing apparatus lifts and descends easily. However, there still has a drawback that the sealing strip may contact the ground even if the door has not yet been closed completely, thus causing the sealing strip to drag on the ground along a distance, and preventing the door from closing completely, so that the latch bolt of the door lock cannot be inserted in the door frame buckle entirely. 
         [0004]    Therefore, it is desirable to provide a self-lifting sealing apparatus to solve the above-described problems, so that the sealing strip descends when the door is closed, and which eliminates or minimizes the possibility of the sealing strip dragging on the ground. 
         [0005]    Accordingly, a primary objective of the present invention is the provision of an improved self-lifting sealing apparatus for the bottom edge of a door. 
         [0006]    Another objective of the present invention is the provision of a self-lifting door weather stripping seal which overcomes the problems of the prior art. 
         [0007]    A further objective of the present invention is the provision of a door seal which automatically lowers when the door is closed and automatically lifts when the door is opened. 
         [0008]    Still another objective of the present invention is the provision of a method of sealing a gap between the lower edge of a door and a door frame threshold wherein the seal moves between a raised position when the door is opened and a lowered position when the door is closed. 
         [0009]    Yet another objective of the present invention is the provision of an automatic door seal having an actuation mechanism opposite the door hinge. 
         [0010]    Another objective of the present invention is the provision of a self-lifting sealing apparatus for a door which is magnetically actuated. 
         [0011]    A further objective of the present invention is a self-lifting door seal which is economical to manufacture, automatic in operation, and durable in use. 
         [0012]    These and other objectives will become apparent from the following description of the invention. 
       SUMMARY OF THE INVENTION 
       [0013]    The self-lifting sealing apparatus of the present invention comprises in inverted U-shaped holder fixed in a channel in the bottom edge of the door. The holder has a downwardly facing opening, with a transmission assembly mounted within the holder to transform horizontal movement into vertical movement. The transmission assembly includes a rod and a batten bar slidably mounted in the holder for horizontal movement. A sealing strip is mounted to the batten bar by a plurality of link arms which allow vertical movement of the sealing strip relative to the holder. 
         [0014]    The self-lifting sealing apparatus further comprises a first magnet mounted on the end of the batten bar and a second magnet mounted in the door frame opposite the first magnet when the door is closed. A first compression spring on the batten bar exerts a reset force in the direction opposite the attractive magnetic forces of the first and second magnets, which have opposite magnetic polarity. 
         [0015]    The magnetic force between the first and second magnets when the door is closed causes the batten bar to slide toward the door frame. When the door is opened, the first spring slides the batten bar in the opposite direction towards the door hinge. 
         [0016]    In an alternative embodiment, the first and second magnets may have the same magnetic polarity, to cause the rod bar to slide horizontally towards the door hinge, with the first spring urging the rod bar in the opposite direction towards the door frame when the door is the opened. 
         [0017]    A second linear spring extends between the transmission rod and the batten bar to exert a force on the batten bar to lift the batten bar as the door begins to open and the magnets are not aligned. 
         [0018]    In the preferred embodiment, the magnets are mounted on the door and door frame opposite the door hinges. In an alternative embodiment, the magnets are mounted on the hinge side of the door and door frame. 
         [0019]    In operation, movement of the transmission rod and batten bar with the sealing strip is controlled by the magnetic force of the magnets. The magnetic force actuates horizontal movement of the transmission rod and vertical movement of the batten bar and seal strip only when the door is closed. When the door is opened, the magnetic force ceases, such that the forces of the first and second springs retract the transmission rod and raise the batten bar and seal strip. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a view showing a door and door frame having the self-lifting seal assembly of the present invention. 
           [0021]      FIG. 2  is an exploded view of the seal assembly. 
           [0022]      FIG. 3  is a sectional drawing of the seal assembly in a raised position. 
           [0023]      FIG. 4  is a sectional view showing the seal assembly in a lowered position. 
           [0024]      FIG. 5  is an enlarged sectional view of the seal assembly showing the first reset spring. 
           [0025]      FIG. 6  is an enlarged sectional view showing the second reset spring. 
           [0026]      FIG. 7  is an end view of the sealing strip of the present invention in a lifted or retracted position. 
           [0027]      FIG. 8  is an end view of the sealing strip in a lowered position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    The self-lifting sealing apparatus of the present invention is generally designated by the reference numeral  10  in drawings. The sealing apparatus  10  is intended for use on the bottom edge of a door  12  mounted by hinges in a door frame  14  for opening and closing movement. The door entryway has a threshold  15  which the sealing apparatus engages when the door  12  is closed to provide a substantially airtight and watertight weather strip seal. 
         [0029]    The self-sealing apparatus  10  includes an inverted U-shaped holder or frame  16  mounted in a channel in the bottom edge of the door  12 . The frame  16  includes spaced apart legs  18  each having an outwardly turned flange  20  which allows the frame  16  to be screwed or otherwise secured to the bottom edge of the door  12 . The legs  18  are spaced apart so as to define a gap or opening  22  therebetween. 
         [0030]    A transmission assembly is mounted in the holder or frame  16  and transmits horizontal movement to vertical movement. More particularly, the transmission assembly includes a rod  24  slidably mounted between the legs  18  of the holder  16  for sliding horizontal movement. While the rod  24  can be mounted to the holder  16  in any convenient manner, in the preferred embodiment shown in the drawings, the plurality of blocks  26 ,  28 ,  30 , each being U-shaped, are welded or fixed to the legs  18  of the holder  16 , so as to slidably support the rod  24 . 
         [0031]    The transmission assembly also includes a batten bar  32  pivotally mounted to the transmission rod  24  by two or move swing arms  34 . Each swing arm  34  has an upper end pivotly coupled to the transmission rod  24  by a pin  36 , and a lower end pivotally coupled to the batten bar  32  by a pin  38 . A seal strip  40  is mounted on and extends downwardly from the batten bar  32 . The seal strip  40  may take various forms, and may be mounted to the batten bar  32  in any convenient manner. 
         [0032]    A first magnet  42  is fixed in a holder  44 . The neck of the holder  44  is hollow and has internal threads for threaded coupling onto the threaded end  46  of the transmission rod  24 , as seen in  FIG. 5 . The threads of the holder  44  and rod end  46  allow the position of the magnet  42  to be horizontally adjusted. 
         [0033]    A second magnet  48  is mounted in the door frame  14  in alignment with the first magnet  42 , shown in  FIGS. 1, 3 and 4 . Preferably, the magnets  42  and  48  have opposite polarity, so that when the door  12  is closed in to the frame  14 , the magnetic force between the magnets  42 ,  48  pulls the transmission rod  24  horizontally toward the door frame  14 . This sliding movement of the transmission rod  24  causes the swing arms  24  to pivot downwardly, thereby moving the batten bar  32  and sealing strip  40  downwardly from the retracted position shown in  FIG. 7  to the extended position shown in  FIG. 8 . In the extended position, the strip  40  provides sealing contact or engagement with the threshold  15  of the door entryway. 
         [0034]    A first reset spring  50  is mounted on the transmission rod  24 . One end of the spring  50  engages the block  26 , while the opposite end of the spring  50  engages a projection  52  of the rod  24 , as shown in  FIG. 5 . In the preferred embodiment, the spring  50  is a compression spring, although it is understood that alternative springs may be used. 
         [0035]    A second reset spring  54  has one end connected to the block  28  and the opposite end attached to the batten bar  32  by a pin  56 , as seen in  FIGS. 2-4 . The linear spring  54  is preferably made of spring wire, and may be round or flat in cross-section, that will deform under stress. When the batten bar  32  and seal strip  40  descend upon horizontal movement of the transmission rod  24  in response to the magnetic force between the magnets  42 ,  48  when the door  12  is closed, the spring  54  bends or deflects. When the magnetic force stops, the spring  54  resets to raise the batten bar  32  and sealing strip  40  upwardly into the holder  16 , as the compression spring  50  forces the transmission rod  24  horizontally within the blocks  28 ,  30 . The linear spring  54  also prevents the batten bar  32  from moving horizontally. As an alternative to the spring wire shown for the second spring  54 , the second spring may be a tension spring to upwardly reset the batten bar  32 . 
         [0036]    When the door  12  moves from the closed position to the open position, the attractive magnetic force between the magnets  42 ,  48  ceases such that the spring  50  retracts the transmission rod  24  and the spring  54  lifts the batten bar  32 , and seal strip  40  moves from the position shown in  FIG. 8  to the position shown in  FIG. 7 . Thus, as the door  12  begins to open, the sealing strip  40  disengages from the threshold  15  thereby minimizing wear on the sealing strip  40  as the door swings open and closed. 
         [0037]    In the preferred embodiment, the magnets  42 ,  48  are mounted opposite the door hinges. Alternatively, the magnets  42 ,  48  can be mounted on the hinge side of the door  12  and door frame  14 . 
         [0038]    In the preferred embodiment, the magnets  42 ,  48  have opposite polarity, such that the transmission rod  24  is pulled toward the door frame  14  as the door  12  closes. Alternatively, the magnets  42 ,  48  can have the same polarity, such that the transmission rod  24  is pushed horizontally away from the door frame  14  when the door  12  is closed, so as lower the batten bar  32  and the seal strip  40 . In both instances, the magnetic force between the magnets  42 ,  48  is greater that the force of the reset springs  50 ,  54 . 
         [0039]    As a further alternative, the spring  54  can be eliminated, in which case stoppers are provided to preclude horizontal movement of the batten bar  32 .