An electrical generation system for a doorway including a door includes a lock mechanism movable between an engaged position and a disengaged position to allow the door to move between a closed position and an open position and a cam coupled to the door. A piezo-electric generator is coupled to the cam. The cam is rotatable with respect to the piezo-electric generator. The piezo-electric generator is operable to produce an electrical current in response to rotation of the cam with respect to the piezo-electric generator, and the electrical current has a frequency that is greater than the number of revolutions made by the cam with respect to the piezo-electric generator.

RELATED APPLICATION DATA 
       [0001]    This application claims priority to U.S. Provisional Application No. 61/643,416 filed May 7, 2012, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to a system for harvesting energy from the movement of the opening or closing of a door, or the movement of various types of hardware on a door (such as a handle or door lock). 
       SUMMARY 
       [0003]    In one aspect, the invention provides an electrical generation system for a doorway including a door. The system includes a lock mechanism movable between an engaged position and a disengaged position to allow the door to move between a closed position and an open position and a cam coupled to the door. A piezo-electric generator is coupled to the cam. The cam is rotatable with respect to the piezo-electric generator. The piezo-electric generator is operable to produce an electrical current in response to rotation of the cam with respect to the piezo-electric generator, and the electrical current has a frequency that is greater than the number of revolutions made by the cam with respect to the piezo-electric generator. 
         [0004]    In another embodiment, the invention provides an electrical generation system for a doorway including a door. The system includes a lock mechanism including a lock and a handle. The handle is movable to move the lock between an engaged position and a disengaged position to allow movement of the door between a closed position and an open position. A cam is coupled to the door and includes a cam axis and a first surface having a plurality of bumps and a plurality of recesses therebetween. A roller is in direct contact with the cam and is positioned to engage the bumps and recesses. One of the roller and the cam is movable about the cam axis with respect to the other of the roller and the cam such that the movement produces a cyclic movement of the roller. A cam driver is coupled to the roller and is cyclically movable in response to cyclic movement of the roller. A piezo-electric element is coupled to the cam driver and is operable in response to movement of the cam driver to produce an alternating electric current in which each cycle starts when the roller is in contact with a first of the plurality of bumps and ends when the roller is in contact with a second of the plurality of bumps, the second bump being adjacent the first bump. 
         [0005]    In another embodiment, the invention provides an electrical generation system for a doorway. The system includes a door slidably supported within the doorway and movable between a closed position and an open position. The door includes a first surface that moves along a substantially linear path as the door moves between the open position and the closed position. A plurality of bumps is positioned along the first surface, each bump cooperating with an adjacent bump to define a recess therebetween. A cam driver is coupled to the first surface. The cam driver is movable into sequential contact with each of the plurality of bumps in response to movement of the door between the open position and the closed position. A piezo-electric element is coupled to the cam driver and is operable in response to movement of the cam driver to produce an alternating electric current in which each cycle starts when the cam driver is adjacent a first of the plurality of bumps and ends when the cam driver is adjacent a second of the plurality of bumps, the second bump being adjacent the first bump. 
         [0006]    In another construction, the invention provides an electrical generation system for a building opening. The system includes a stationary frame surrounding at least a portion of the opening, a movable member supported in the frame for movement between an open position and a closed position, and a liner positioned between the stationary frame and the movable member. The liner deflects in response to movement of the movable member. A piezo electric element is coupled to the liner and is operable to generate an electric current in response to the deflection of the liner. 
         [0007]    Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a door including a door lock and an electrical generation system; 
           [0009]      FIG. 2  is an enlarged perspective view of a portion of the door of  FIG. 1  illustrating the electrical generation system; 
           [0010]      FIG. 3  is a perspective view of another electrical generation system suitable for use with the door of  FIG. 1 ; 
           [0011]      FIG. 4  is a perspective view of another electrical generation system suitable for use with the door and the door lock of  FIG. 1 ; 
           [0012]      FIG. 5  is a perspective view of another electrical generation system suitable for use with the door of  FIG. 1 ; 
           [0013]      FIG. 6  is a perspective view of another electrical generation system suitable for use with the door and the door lock of  FIG. 1 ; 
           [0014]      FIG. 7  is a perspective view of another electrical generation system suitable for use with a sliding door; 
           [0015]      FIG. 8  is a perspective view of an electrical generation system and a cam suitable for use with the door of  FIG. 1 ; 
           [0016]      FIG. 9A  is a perspective view of one embodiment of the electrical generation system including a door frame liner enclosing piezo-electric film strips with the liner in a non-compressed state; 
           [0017]      FIG. 9B  is a perspective view of the electrical generation system of  FIG. 9A  with the liner in a compressed state; 
           [0018]      FIG. 10A  is a perspective view of another construction the electrical generation system including a door frame liner enclosing piezo-electric fibers with the liner in a non-compressed state; 
           [0019]      FIG. 10B  is a perspective view of the electrical generation system of  FIG. 10A  with the liner in a compressed state; 
           [0020]      FIG. 11  is a schematic illustration of a circuit suitable for use with the electrical generation system of any of the foregoing figures. 
       
    
    
       [0021]    Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
       DETAILED DESCRIPTION 
       [0022]    The present invention provides various embodiments of doors and door systems that include an electrical generation system that utilizes piezo-electric generators to generate electricity from the movement of a door, or the movement of various door related mechanisms. The electricity from such electrical generation systems can be used to directly power electronic door accessories such as an electric door lock, security keypads, lights, door openers, biometric security devices (such as fingerprint readers, etc.), or other such powered devices. In other arrangements, the piezo-electric generators are used to recharge the batteries that power the aforementioned accessories. 
         [0023]    In one embodiment, the electrical generation system includes a door mechanism, a cam and a piezo electric generator mechanism. The door mechanism can be any moving mechanism that is utilized on a door, such as a door handle, door lock, door closer, or the door itself. In one construction, a cam is operatively connected to the door mechanism so that when the door mechanism is actuated, the movement of the door mechanism imparts movement to the cam. 
         [0024]      FIG. 1  illustrates a simplified version of a door  10  that includes a piezo-electric generator mechanism  15  of the invention. As illustrated in  FIG. 1 , the door  10  is supported within a door frame  20  by three hinges  25  that allow the door  10  to pivot about a hinge axis. A lock mechanism  30  is positioned within the door  10  and is operable to selectively engage the door frame  20  to maintain the door  10  in a closed position. A handle  35  extends from the lock mechanism  30  and is actuatable by a user to selectively engage or disengage the lock mechanism  30  and the frame  20  to allow the user to open and close the door  10 . In preferred constructions, weather stripping  40  (sometimes referred to as a door frame liner)or other flexible items are positioned between the door  10  and the door frame  20  such that when the door  10  is closed, a better seal is formed between the door  10  and the door frame  20 . 
         [0025]    The piezo-electric generator  15 , better illustrated in  FIG. 2  includes a roller  45 , a cam driver  50 , a piezo-electric member  55 , and electrical conductors  60  or wires that direct the generated electricity to a point-of-use. In preferred constructions, the piezo-electric member  55  includes a stack of piezo-electric elements  65  arranged such that an applied force on one of the elements  65  is applied to all of the elements  65 . The piezo-electric member  55  used in the piezo-electric generator mechanism  15 , can be any suitable commercially available piezo-electric member  55 . 
         [0026]    The cam driver  50  is positioned adjacent the piezo-electric member  55  and engages the member  55  such that any displacement of the cam driver  50  is translated to the piezo-electric member  55 . In the illustrated construction, the cam driver  50  includes a rectangular cross-section bar that extends from the piezo-electric member  55  and supports the roller  45 . Other shapes and arrangements of the cam driver  50  are also possible. 
         [0027]    As illustrated in  FIG. 2 , the roller  45  includes a cylindrical wheel that is supported for rotational movement by the cam driver  50 . The outer surface  70  of the roller  45  is substantially smooth and is positioned to engage a cam  75 . 
         [0028]    The cam  75  includes a cylindrical wheel with a plurality of bumps  80  formed on the outermost cylindrical surface  85 . The cam  75  is coupled to the uppermost hinge  25  in the illustrated construction such that the cam  75  rotates with the door  10  as it is opened and closed. The bumps  80  of the cam  75  are sized and spaced such that the roller  45  moves in a substantially radial direction as the cam  75  rotates. For example, if one selected a piezo-electric member  55  that efficiently operates when excited at 50 Hz for use on a door that moved through 90 degrees of rotation in 10 seconds, one would provide a cam  75  having about 2000 bumps  80  around the circumference. Each bump  80  would have a height about equal to the desired displacement (e.g., 0.005 inches, 0.13 mm) and the roller  45  would be sized to fit between the bumps  80  to give the desired displacement at the cam driver  50 . 
         [0029]    The cam and roller interface is designed to apply pressure to the roller  45  as it moves on the surface of the cam  75 . The roller  45  in turn moves the cam driver  50 . The cam driver  50  can be any structural component that links the roller  45  to the piezo-electric member  55 . As the cam driver  50  is moved it actuates the piezo-electric member  55 , which in turn generates electricity in response to the deformations imparted to the piezo-electric elements  65 . 
         [0030]    Suitably, the cam and roller interface is designed such that there are bumps  80  or depressions on either the cam  75 , the roller  45 , or both, such that the movement of the cam  75  over the roller  45  creates a frequency and amplitude of movement in the cam driver  50  that actuates the piezo-electric member  55  in an efficient fashion. Suitably, in one embodiment, the bump  80  or depression arrangement on the cam  75  or the roller  45  is such that the piezo-electric member  55  is actuated at a frequency of about between 50-200 Hz with an amplitude of about 1-10 thousandths of an inch (0.025-0.25 mm). 
         [0031]    The piezo-electric generator  15  of  FIG. 2  remains stationary while the cam  75  rotates with the hinge  25  to provide the desired excitation of the piezo-electric member  55 .  FIG. 3  illustrates another construction in which the piezo-electric generator  15  is coupled to and moves with the door  10  while the cam  75  remains fixed. Thus, the piezo-electric generator  15  rotates around the cam  75  to produce the same excitation as was provided with the construction of  FIG. 2 . The construction of  FIG. 3  is advantageous in that the wiring  60  from the piezo-electric member  55  can be directly connected to the device being powered or the batteries  90  (shown in  FIG. 11 ) being charged if they are also coupled to the door  10  without having to pass wires between the stationary frame  20  and the moving door  10 . One of ordinary skill in the art will realize that the cam  75  and the piezo-electric generator  15  can be positioned in many different ways without deviating from the invention. In addition, one of ordinary skill in the art will realize that while the cam  75  illustrated in  FIGS. 1-3  is shown as being completely cylindrical, other constructions could use a portion or sector of the cylinder since most doors  10  rotate less than about 180 degrees. 
         [0032]    Another construction of the electrical generation system that could be used alone, or with the construction of  FIGS. 1-3 , is shown in  FIG. 4 . The door handle  35  is connected to a spindle  95  which operatively supports the cam  75 . The cam  75  is operatively connected to the spindle  95  such that when the handle  35  is turned, both the spindle  95  and the connected cam  75  rotate together. The cam  75  outer circumference  85  has bumps  80  and depressions  100  situated thereon. The roller  45  is positioned to be in connection with the outer circumference  85  of the cam  75 , such that when the cam  75  is turned, a portion of the outer circumference  85  of the cam  75  rolls across the roller  45 , the roller  45  traveling over the bumps  80  and depressions  100  causing the roller  45  to move the cam driver  50  to actuate the piezo-electric member  55 . As discussed with regard to  FIGS. 1-3 , the bumps  80  are sized and spaced to provide the desired excitation frequency and amplitude for the piezo-electric member  55  during normal rotation of the handle  35 . 
         [0033]      FIG. 5  illustrates another arrangement in which the piezo-electric generator  15  is oriented in a direction that is substantially parallel to the hinge axis rather than normal to that axis as illustrated in  FIGS. 1-3 . In this arrangement, the bumps  80  are moved from the circumferential outer surface  85  of the cam  75  to the outermost edge of one of the substantially planar faces  105  of the cam  75 . As with prior constructions, the bumps  80  are sized and spaced to provide excitation of the piezo-electric member  55  at the desired frequency and amplitude. As with the constructions of  FIGS. 1-3 , the piezo-electric generator  55  could be coupled to the door  10  rather than the frame  20 , if desired. 
         [0034]    Another embodiment of the electrical generation system is shown in  FIG. 6 . A lock mechanism  110  includes a rotating spindle  95  that is operatively connected to the cam  75  such that the rotating spindle  95  and the connected cam  75  rotate together. The cam  75  includes a substantially planar surface  105  that terminates at an outer circumference  85 . A plurality of bumps  80  and depressions  100  are formed or attached to the substantially planar surface  105  adjacent the outer circumference  85 . The piezo-electric generator  15  is positioned such that the roller  45  contacts the substantially planar surface  105  of the cam  75  and is displaced in a direction that is substantially parallel to the spindle axis in response to the bumps  80  moving past the roller  45  during rotation of the handle  35 . As with prior constructions, the bumps  80  are sized and spaced to excite the piezo-electric member  55  at the desired frequency and amplitude. 
         [0035]      FIG. 7  illustrates yet another arrangement of the invention. The construction of  FIG. 7  is adapted to operate with sliding doors  110  rather than rotating doors  10 . The piezo-electric generator  55  is positioned in the door frame  20  adjacent a top or bottom edge  115  of the door  110 . A strip  120  is positioned along the adjacent edge  115  of the door  110  and includes a plurality of bumps  125 . As with prior constructions, the roller  45  of the piezo-electric generator mechanism  15  engages the bumps  125  and moves in response to the movement of the bumps  125  past the roller  45 . As with prior constructions, the bumps  125  are sized and spaced to excite the piezo-electric member  55  at a desired frequency and amplitude. In another construction, the bumpy strip  120  is positioned on the door frame  20  and the piezo-electric generator mechanism  85  is coupled to and moves with the door  110 . 
         [0036]      FIG. 8  illustrates an arrangement of a piezo-electric generator mechanism  130  and a cam  135  in which the bumps  80  are applied to a roller  140  rather than a cam  135 . This arrangement could be applied to any of the arrangements described herein. The bumps  80 , the cam  135 , and the roller  140  would all be sized and spaced to provide excitation of the piezo-electric member  55  at the desired frequency and with the desired amplitude. 
         [0037]    In another construction illustrated in  FIGS. 9 and 10 , the door frame liner  40  or other flexible interface between the door  10  and the frame  20  is employed to generate electricity using piezo-electric elements  145 . 
         [0038]    As illustrated in  FIG. 1 , the electrical generation system includes the door  10 , the door frame  20 , and weather stripping  40  (or door frame liner) positioned beneath the door  10 . The weather stripping  40  includes a strip of elastic material  150  which at least partially encloses one or more piezo-electric members  155 . As illustrated in  FIG. 9 , a series of piezo-electric members  155  are spaced apart from one another with each, including a plurality of piezo-electric elements  160  supported between the uppermost surface of the strip  150  and the lowermost surface of the strip  150 . The elastic strip  150  can include fabric, rubber, plastic, or any other elastic material. In some embodiments, the elastic strip  150  can include conductive plastic or conductive rubber. Any suitable commercially available piezo-electric members  155  may be used. 
         [0039]      FIG. 9A  illustrates the strip  150  in a relaxed position such as when the door  10  is open, while  FIG. 9B  illustrates the strip  150  in a compressed position such as the position it takes when the door  10  is in the closed position. As the strip  150  moves between the positions of  FIG. 9A and 9B , the piezo-electric elements  145  are compressed or expanded slightly, thereby producing an electric current. The current is directed to the point-of-use and is used in a manner similar to that described with regard to the prior arrangements. 
         [0040]      FIGS. 10A and 10B  illustrate another arrangement of a strip  160  in which piezo-electric members  162  include piezo-electric fibers  165  that can be attached, woven or enclosed by the elastic strip  160 . The piezo-electric members  162  generate electricity which can be stored in the battery  90  (shown in  FIG. 11 ) or used to power an electronic door accessory  165  (e.g., lock, key pad, light, etc.). In one embodiment, the elastic strip  160  of the weather stripping  40  is either conductive plastic or conductive rubber, and the weather stripping  40  itself can be used to transmit electricity from the piezo-electric members  162  to electric door accessory  165  (shown in  FIG. 11 ). In other embodiments the electricity can be transmitted from the piezo-electric members  162  by standard electrical wires that can be connected or embedded in the weather stripping  40 . 
         [0041]    It should be noted that while some of the embodiments are described as including batteries, virtually any energy storage device (e.g., supercaps, ultracaps, etc.) could be employed in place of or in conjunction with the batteries described herein. 
         [0042]    Various features and advantages of the invention are set forth in the following claims.