Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 13/488,716, filed Jun. 5, 2012, the disclosure of which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to a door opener and, more particularly, to a power door opener that allows a user to force open a door with enhanced safety and reduced noise. 
     In the law enforcement and fire services, first responders arriving at the destination are often faced with locked doors barring ready access to a building or room within a building. In the case of firefighters, the increasing use of security locks and metal doors require firefighters to carry pry bars, axes, sledge hammers and even hydraulic tools to force doors open. As is known, the time required to force a door open for the firefighter to gain access to a potentially dangerous fire is critical as the danger of injury to a firefighter increases as the fire is allowed to continue unabated such that the faster the firefighter can attack the fire, the better the outcome with greater safety to the firefighter. 
     In addition, with many fires in a closed room or confined area, the fire can be starving for oxygen and the opening of the door allows air into the room and the fire tends to blow back in the direction of the open door toward the source of the oxygen, thereby putting any personnel positioned in the doorway at great risk. It is therefore a danger to a fireman to be positioned within the doorway of a door as it is being opened to access a fire within the closed room. 
     In the case of law enforcement, in addition to the tools use by the fire department, law enforcement personnel sometimes use battering rams. When the officers use a battering ram, they can be exposed to danger since the user of the battering ram normally must stand in front of the door. This danger is increased if the door is not opened on the first try such that any occupants are alerted to the fact of the law enforcement officers attempting to gain entry into the room and can take measures, possible deadly, to repel any entry into the room by the law enforcement personnel. 
     Another method commonly used to force open a door is by using a manually pumped hydraulic ram. With the hydraulic ram, the ram is inserted in the space between the door and the door jamb in the vicinity of the lock and the hydraulic ram forces the door jamb apart such that the jamb is displaced away from the door sufficiently to disengage the lock and allow the door to be opened. With this method, the user is required to hand pump the tool until the door is spread enough to force it open. Again, during the process, the user is exposed to danger from the occupiers inside the premises. 
     Accordingly, the use of the hydraulic ram is useful for flush doors where the tool can be inserted into the space between the door and the door jamb but is extremely difficult to use if the door is flush to the inside leaving a 4-6 inch recess between the outside door sill and the door. 
     In addition the military also has a need to open a locked door in gaining access to a building or room and, using a battering ram or hydraulic tool, there is the addition danger that if the ram does not work to open the door on the first try, the occupants inside the room are warned and can react by firing weapons through the door in an attempt to thwart the entry by the military personnel, thereby creating a dangerous situation to those attempting to gain entry. 
     Accordingly, it would be advantageous to have a door opener that could be used to force the opening of a door where the use of the door opener could be relatively quiet so as to avoid alerting the occupants of the room and which also can allow the personnel attempting to open the door to be physically located aside the door and not directly in front of the door at the time the entry is attempted. 
     SUMMARY OF THE INVENTION 
     Now, in accordance with the present invention, there is a power door opener that has a power actuator that is basically a housing having an actuator shaft movable with respect to the housing between a closed position and extended position where the actuator shaft is extended outwardly from the housing. An electric motor and associated gear train cause the actuator shaft to move between its closed and extended positions. 
     A fixed push plate is affixed to the housing and may be affixed by screw threads, welding or other means of affixation. The fixed push plate is preferable cylindrical and surrounds the actuator shaft and has a distal end with a fixed pry member that extends radially outwardly from the fixed push plate. The fixed pry member is preferably tapered inwardly in the outward direction. 
     A movable push plate is affixed to the end of the actuator shaft and moves therewith and also has a movable pry member that extends outwardly therefrom. When the actuator shaft is in its closed position, the fixed and movably pry members are in alignment and form a tapered inwardly combined linear edge that is suitable for inserting into the space between a door and a door jamb. 
     In the method of using the power door opener to force open a door, the combined edge of the fixed and movable pry members are inserted into that space between the door and the door jamb and the motor is activated to move the actuator shaft and the movable push plate outward to progressively separate the movable push plate from the fixed push plate, thereby increasing the width of the space between the door and the door jamb sufficiently to disengage the door latch or locking mechanism from the door jamb and enable the door to be forced open. 
     In an alternate embodiment, the power door opener is double ended and the power actuator has a front side and a rear side. An extension is affixed to the rear side of the power actuator that extends outwardly from the rear side a predetermine length to its distal end. As such the double ended power door opener can span between the two vertical door jambs with the distal end of extension contacting one of the door jambs and the movable push plate contacting the other door jamb. 
     Again, as the motor is activated, the actuator shaft moves outwardly to its extended position, thereby increasing the distance between the distal end of the extension and the movable push plate so as to force the door jambs outward sufficiently to disengage the door latch or lock from the door jamb and enable the user to force open the door. 
     With this embodiment there may be more than one extension provided with the door opener such that the user can interchange one door extension for another. The door extensions can be of different lengths such that the user can select the appropriate extension based on the width or distance between the opposite door jambs. 
     Other features of the present door opener will become more apparent in light of the following detailed description of a preferred embodiment thereof and as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of an exemplary embodiment of the power door opener of the present invention; 
         FIG. 2  is a perspective view of the power door opener of  FIG. 1 ; 
         FIG. 3  is a view illustrating the use of the  FIG. 1-2  embodiment; 
         FIG. 4  is an exploded view of an alternate exemplary embodiment of the power door opener of the present invention; 
         FIG. 5  is a perspective view of the power door opener of  FIG. 4 ; and 
         FIG. 6  is a view illustrating the use of the  FIG. 4-5  embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIG. 1 , there is shown an exploded view of a power door opener  10  constructed in accordance with the present invention. As can be seen, the power door opener  10  is comprised of a power actuator  12  that is commercially available, for example, from Burr Engineering of Battle Creek, Mich. The power actuator  12  is basically a housing  14  containing a 12 volt motor  16  and the necessary gearing and power train and an outer cylindrical tube  18  extending outwardly from the housing  14  within which there is a movable actuator shaft  20 . 
     In the operation of the conventional power actuator  12 , the actuator shaft  20  can be moved between its closed position as shown in  FIG. 1  and an extended position (not shown) where the actuator shaft  20  is extended linearly outwardly from the housing  14 . Typically, the actuator shaft  20  can be moved about 4 inches in its movement between the closed position and the extended position and that movement is driven in both directions by the motor  16 . 
     In accordance with the present invention, therefore, a cylindrical fixed push plate  22  is positioned over the outer cylindrical tube  18  with the fixed push plate  22  having a distal end  24  and proximal end  26 . The proximal end  26  is affixed to the housing  14  by means of screw threads, welding or other affixation method such that the fixed push plate  22  is firmly affixed to the housing  14  in its position surrounding the outer cylindrical tube  18 . 
     At the distal end  24  of the fixed push plate  22 , there is a fixed pry member  30  that extends radially outwardly from the fixed push plate  22  and the fixed pry member  30  tapers inwardly in the outward direction forming a relatively straight, narrow edge  32  at the outer end thereof. As shown the inward taper is formed on fixed pry member  30  on the side away from the distal end  24  of the fixed pry member  30 , however, the location of the taper may be on either side of the fixed pry member  30  or on both sides thereof. 
     A movable push plate  34  is affixed to the outer end of the movable actuator shaft  20  by means such as a pin  36  that extends through a suitable opening  38  in the movable push plate  34  and a corresponding, aligned opening  40  in the outer end of the actuator shaft  20 , thereby securing the movably push plate  34  firmly and securely to the movable actuator shaft  20 . The movable push plate  34  has a movable pry member  42  that extends outwardly from the movable push plate  34  and, in the exemplary embodiment, the movable pry member  42  is bifurcated, having two prongs  44  with a space  46  therebetween. Both of the prongs  44  taper inwardly in the outer direction and, as with the fixed pry member  30 , the taper may be on the side of the prongs  44  facing the power actuator  12 , facing away from the power actuator  12 , or on both sides of the prongs  44 . 
     Turning then to  FIG. 2 , taken along with  FIG. 1 , there is shown a perspective view of the power door opener  10  with the actuator shaft  20  in the closed position. As can be seen, the fixed pry member  30  aligns with the two prongs  44  of the movably pry member  42  since the fixed pry member  30  occupies the space  46  intermediate those prongs  44 . As such, there is formed a continuous edge by the combination and alignment of the fixed pry member  30  and the movable pry member  42 . 
     Turning then to  FIG. 3 , taken along with  FIGS. 1 and 2 , there is a view of the present power door opener  10  and illustrating its use to force open a door  48 . In  FIG. 3 , the user  50  has inserted the continuous edge of the power door opener  10  into the narrow space between the door  48  and the door jamb  52 . 
     As such, as electricity is fed to the motor  16  of the power actuator  12 , the actuator shaft  20  will move outwardly with respect to the housing  14 . The outward movement of the actuator shaft  20  will create an ever increasing space between the fixed pry member  30  and the movable pry member  42  to force the opening between the door  48  and the door jamb  52  to expand to eventually reach a linear gap where the lock or door latch will be clear of the door jamb  52 . At that point, the door  48  can be opened and access gained to the interior of the building or room. 
     Turning next to  FIG. 4 , there is shown an exploded view of an alternative exemplary embodiment of the present invention and showing the double ended power door opener  54 . 
     With the  FIG. 4  embodiment, the power actuator  12  is basically the same as that described with respect to  FIGS. 1-3  and the same identification numbers are with the  FIG. 4  embodiment for the same components. 
     However, in the present embodiment the double ended power door opener  54  is designed for forcing open a door by a different method. With the  FIG. 4  embodiment, the power actuator  12  has a front side  56  and a rear side  58 . As with the  FIG. 1  embodiment the movable actuator shaft  20  extends out of the front side  56  of the power actuator  12  and there is, again, a movable push plate  34  affixed to the outer end of the actuator shaft  20  and has a movable pry member  42 . 
     In this embodiment, however, the movable push plate  34  is reversed such that the bifurcated movably pry member  42  faces outwardly and therefore does not align with the fixed pry member  30  when the actuator shaft  20  is in the closed position. The orientation of the movable push plate  34  can be established by its affixation to the outer end of the actuator shaft  20  with pin  36 . 
     Affixed to the rear side  58  of the power actuator  12  is a long extension  60  and the long extension  60  can be affixed to the power actuator  12  by means of a pin  62  that passes through an opening  64  in the long extension  60  and also through an opening  66  formed in a connector  68  that is affixed to or a part of the power actuator  12 . 
     As such, the long extension  60  is firmly affixed to the rear side  58  of the power actuator  12  and there is an extension push plate  70  affixed to the free end of the long extension  60 . Again, the connection between the extension push plate  70  and the long extension  60  may be by means of a pin  72  passing through an opening  74  in the extension push plate  62  and a hole  76  formed in the free end of the long extension  60 . 
     The extension push plate  70  also includes an extension pry member  78  that, again, may be bifurcated in a similar manner to the movable pry member  42  ( FIG. 1 ). There may also be as short extension  80  that is provided so that the user can install the short extension  80  as an alternative to the long extension  60  depending on the width of the doorway that is to be distorted in forcing a door open. As can be readily seen, the short extension  80  can be installed and affixed to the power actuator  12  in the same manner as the long extension  60  and the only difference is that the overall length of the double ended power door opener  54  is different. 
     Turning then to  FIG. 5 , there is shown a perspective view of the double ended power door opener  54  of  FIG. 4 . As can be seen, the double ended power door opener  54  includes the extension push plate  70  at one end of the double ended power door opener  54  with the movable push plate  34  at the other end with a known linear distance therebetween. As such, that linear distance can be changed by activating the power actuator  12  so as to move the actuator shaft  20  to extend outwardly or retract inwardly with respect to the housing  14 . 
     Accordingly, as will become clear, the double ended power door opener  54  can be placed in a doorway between two vertical door jambs and with the actuator shaft  20  in the closed position. Upon activation of the power actuator  12 , the movable push plate  34  can be extended outwardly to increases the linear distance between the extension push plate  70  and the movable push plate  34  to spread the door jamb to release the door to be forced open. 
     That action is illustrated in  FIG. 6 , taken along with  FIGS. 4 and 5 , where the double ended power door opener  54  is shown in operative position intermediate opposed door jambs  82 ,  84 . As can be seen, the movable push plate  34  is fitted against the door jamb  82  while the free end of the long extension  60  is fitted against door jamb  84 . In this embodiment, a remote controller  86  is connected to the power actuator  12  so that the user can be positioned away from the doorway when the door is forced open. As such, the user can be protected by the walls that surround the door  88  and not be in the way of possible danger that may be present within the room being entered. 
     Accordingly, by activating the power actuator  12 , the door jambs  82 ,  84  will be spread apart as the actuator shaft  20  moves from a closed position to an extended position, thereby freeing the lock from its connection to a door jamb and allow the user to force the door open for access to the room. 
     While the present invention has been set forth in terms of a specific embodiment or embodiments, it will be understood that the present power door opener herein disclosed may be modified or altered by those skilled in the art to other configurations. Accordingly, the invention is to be broadly construed and limited only by the scope and spirit of the claims appended hereto.

Technology Category: 1