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BACKGROUND OF THE INVENTION 
     This invention relates generally to handle operated doors incorporating an electronic lock system which may include other security measures such as cylindrical locks or mortise deadbolts. More particularly, the present invention relates generally to a modular electronic door security system in which the access control features of the system may be placed anywhere on the outside face of the door. 
     For buildings which have multiple interior secured areas, such as apartment houses, dormitories, hotels, etc., it is common for the door to incorporate an electronic lock system such as that disclosed in U.S. Pat. No. 5,473,236, which is assigned to the assignee of the present invention. The door essentially separates a secured area, such as a room or office, from an unsecured area, such as a hallway or foyer. The electronic lock system typically incorporates a terminal or electronic reader on the unsecured side or outside face of the door and a control module generally fixed to the secured side or inside face of the door. The control module stores a set of valid inputs, compares received inputs to stored inputs and produces a release signal used to unlock the door upon reception of a valid input. The inputs are typically numeric codes which can be encoded on magnetic cards, electronic keys containing ROM chips or simply keyed into a keypad. A micro-motor or solenoid is typically used to unlock the latch assembly and allow entry. 
     In known arrangements, the electronic reader is mounted in the immediate vicinity of the door handle. Often, the trim covering the lockset incorporates the electronic reader above the door handle. While this configuration is appropriate for the vast majority of uses, it may cause inconvenience for those individuals confined to a wheelchair or similar device. A seated person may not be able to conveniently activate the electronic reader and operate an adjacent handle at the same time. 
     Architects and other designers may wish to place the terminal or electronic reader well away from the door handle for aesthetic or other design purposes. Some interior doors may not accommodate an electronic lock system which requires the control module and input device to be mounted immediately adjacent to the door handle. 
     The location of the control and input devices may also effect the durability of the electronic lock system. The opening and closing of a door generates forces which may be harmful to components mounted to the door. Doors frequently slam or experience sudden shocks while in the process of opening or closing, e.g., someone or something hitting the open door. Components mounted at the latch edge of a door are subject to the greatest of these forces. 
     Accordingly, there is a need in the art for a modular electronic door security system which may be custom configured to suit a given application. 
     SUMMARY OF THE INVENTION 
     Briefly stated, the invention in a preferred form is a modular electronic door security system which allows the input device and/or control module to be mounted anywhere on the face of the door. The modular electronic door security system has particular applicability in connection with doors in facilities where handicapped accessibility is a priority. 
     The modular electronic door security system affords a level of flexibility which allows the system to be configured for a particular application. The modular system comprises an input device placed on the face of the door, a control module and an electro-mechanical lock assembly. The input device, control module and electro-mechanical lock assembly are in communication with one another. This communication may be accomplished via by conductors which are internal to the door. Communication may also be maintained by low power radio frequency (RF) or devices which produce an optical communications link. The necessary transmission and reception components of such wireless systems may be incorporated into each component of the system. The system may be battery powered for a stand alone capability or may be connected to an external power source through the hinge edge of the door. 
     The input device may incorporate a card reader, key pad, contact activatable dataport or other electronic security reader. The control module may be a separate unit or may be incorporated into the input device. The control module processes inputs received by the input device and generates a release signal to the electro-mechanical lock assembly upon reception of a valid input. The modular design of the door security system allows the control module and/or electronic reader to be mounted anywhere on the surface of the door. 
     The electro-mechanical lock assembly is mounted between the door handles and adjacent to the latch edge of the door. The electro-mechanical lock assembly incorporates a lockset, lever handles on the interior and exterior sides of the door and an electronic clutch or coupling device. The lockset has an actuator for operating the latch. The clutch includes a pin which is carried by the actuator. The lever handles operate a notched hub which is coaxial with the latch actuator. The clutch mechanism moves the pin from a non-engaged position where the hub and actuator move independently to an engaged position where the pin enters the hub notch, mechanically coupling the hub and actuator. The engaged position corresponds to unlocking the door because it allows lever movement to operate the latch and open the door. 
     A key operated override may be employed to override the security system and unlock the door. 
     An object of the invention is to provide a new and improved modular electronic door security system which is aesthetically pleasing and provides additional convenience to the handicapped user. 
     Another object of the invention is to provide a new and improved modular electronic door security system which gives architects and designers a wide range of flexibility in configuring installation of security system components. 
     A further object of the invention is to provide a new and improved modular electronic door security system which facilitates electrical interconnections that are internal to the door. 
     A yet further object of the invention is to provide a new and improve modular electronic door security system in which the modular components communicate using wireless technology. 
     A yet further object of the invention is to provide a new and improved modular electronic door security system which optionally includes a novel key override feature. 
    
    
     Other objects and advantages of the invention will become apparent from the drawings and the specification. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1A is a partial perspective view of the secured side of a door incorporating a modular electronic door security system in accordance with the present invention; 
     FIG. 1B is a partial perspective view of the unsecured side of the door of FIG. 1A; 
     FIG. 2A is a partial front view, partly in phantom, of a door prepared for installation of the modular electronic door security system as configured in FIGS. 1A and 1B; 
     FIG. 2B is a partial side view, partly in phantom, of the door of FIG. 2A; 
     FIG. 2C is a partial rear view, partly in phantom, of the door of FIG. 2A; 
     FIG. 3 is a fragmentary front view, partly broken away, of the modular electronic door security system of FIG. 1A; 
     FIG. 4 is a partial sectional view of the modular electronic door security system of FIG. 3, taken along line  4 — 4  thereof; 
     FIG. 5A is a fragmentary frontal perspective view of a door incorporating an alternative embodiment of the modular electronic door security system in accordance with the present invention; 
     FIG. 5B is a fragmentary frontal perspective view of a door incorporating an alternative embodiment of the modular electronic door security system in accordance with the present invention; 
     FIG. 6 is a fragmentary frontal perspective view of a door incorporating an alternative embodiment of the modular electronic door security system in accordance with the present invention; 
     FIG. 7 is a side view of the outside escutcheon assembly of a lock set which forms part of the modular electronic door security system in accordance with the present invention; 
     FIG. 8 is a cross-sectional view of the outside escutcheon assembly of FIG. 7 taken along line  8 — 8  thereof; 
     FIG. 9 is an interior perspective view, partly in phantom, of the outside escutcheon assembly of FIG. 7 with the components in a locked configuration; 
     FIG. 10 is an interior perspective view, partly in phantom, of the outside escutcheon assembly of FIG. 7 with the interior components illustrated in an unlocked configuration; 
     FIG. 11 is an interior perspective view, partly in phantom, of the outside escutcheon assembly of FIG. 7 with the interior components illustrated in an override configuration; 
     FIG. 11A is a schematic representation of the components of an alternative embodiment of the key override in accordance with the present invention; 
     FIG. 12 is a fragmentary side view of a door incorporating a modular electronic door security system in accordance with the present invention; 
     FIG. 12A is a fragmentary side view of a door incorporating an alternative embodiment of the modular electronic door security system in accordance with the present invention; 
     FIG. 13 is a frontal view, partly in phantom, of a door which has been prepared for installation of the modular electronic door security system in accordance with the present invention; and 
     FIG. 14 is a side view, partly in phantom, of the door of FIG.  13 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings, wherein like numerals represent like parts throughout the figures, a modular electronic door security system in accordance with the present invention, which may be installed in numerous configurations and employ a variety of components for a given application is generally designated by the numeral  10 . The modular electronic door security system  10  is used in combination with a door  12 . The door  12  separates an unsecured area from a secured area and has an inside face  14 , generally facing the secured area and an outside face  15 , generally facing the unsecured area. 
     The modular electronic door security system  10  comprises an input device  18 , a control module  30 , and an electro mechanical lockset  16  affixed to a door  12 . The door  12  may be solid or hollow and may be made of steel, wood, or other door construction material. FIGS. 1A and 1B illustrate one possible installed configuration for the modular electronic door security system  10 . An outer escutcheon assembly  50  is mounted to the outside face  15  of the door  12 . An inner escutcheon assembly  51  is mounted to the inside face  14  of the door  12 . A lockset  16   a  having a cylindrical latch  17 , mechanically links the inner escutcheon assembly  51  and the outer escutcheon assembly  50 . The latch  17  projects from the latch edge  42  of the door  12  and is operable by a handle  18  at the exterior side and a handle  19  at the secured side. The handles  18  and  19  may assume various forms including levers as illustrated, knobs, and other well known operator hardware. 
     FIGS. 2A-2C illustrate the preparation of a solid core door to receive the components which together form the modular electronic door security system  10 . A first bore  20  is created between the inside and outside faces  14 ,  15  of the door  12  to accommodate installation of a lockset. A second bore  21  transversely intersects with the first bore  20  to accommodate projection of a latch  17  from the latch edge  42  of the door  12 . The first bore  20  and second bore  21  represent the typical preparation of a door for the installation of a cylindrical latch lockset. 
     Door preparation for the embodiment of the modular electronic door security system illustrated in FIGS. 2A-2C,  3 ,  4 ,  12 ,  13  and  14  must include pathways for the necessary electrical connections between the modular components comprising the system. For this purpose, a third bore  22  must be created between the inside face  14  and the outside face  15  of the door at a location selected for mounting of an input device. This bore  22  will serve as a pathway for conductors connecting an input device  40  to the control module  30 . A fourth bore  24 , coaxial with the second bore  21 , penetrates the core of the door generally perpendicular to the latch edge  42 . The fourth bore  24  penetrates toward the hinge edge  44  and terminates at a location vertically above or below the third bore  22 . Whether the fourth bore  24  will terminate above or below the third bore  22  depends on the location selected for installation of the input device  40 . 
     A slot  28  is then formed on the inside door face  14  connecting the fourth bore  24  with the third bore  22 . A partial bore  29  is drilled in the outside door face  15  to connect with the fourth bore  24 . The object of the partial bore  29 , fourth bore  24  and slot  28  is to form a conductor pathway from the location selected for the third bore  22  (the mounting location of the input device and control module) and the electrically actuated portions of the lockset  16 . The slot  28  will be covered by the control module  30  or other trim to create a finished appearance on the inside face  14  of the door  12 . 
     FIGS. 13 and 14 present an alternative approach to preparation of a solid core door. FIG. 13 illustrates the outside face  15  of a door  12  where the input device  40  is to be mounted in the center of the outside face  15  of the door and several inches below the lockset. Rather than drill the fourth bore perpendicular to the latch edge  42  of the door, the fourth bore  24  is drilled along line A to intersect directly with the third bore  22 . The previously created first bore  20  and second bore  21  will allow the fourth bore  24  to be oriented at a range of angles to the latch edge  42 . The angles available allow a direct path between component locations to be formed internally, without resort to opening a slot on the inside face of the door. This configuration may be useful for a combined input/control module having no component mounted to the inside face  14  of the door  12 . In this configuration, partial bore  29  may take the form of a short slot connecting the fourth bore  24  with the area to be covered by the outer escutcheon assembly  50  (see FIG.  13 ). 
     Doors may be prepared and the components of the modular electronic door security system installed prior to delivery to the construction site. Factory configured doors relieve the installer of the need to bore holes and/or run wires through the interior of the door. The angled boring necessary to the installation illustrated in FIGS. 13 and 14 can be accurately accomplished in a factory setting. A factory installation allows for quality control of the electro-mechanical aspects of the installation as well as the fit, finish and cosmetic appearance of the modular electronic door security system. 
     With reference to FIGS. 3 and 4, the input device  40   a  is electrically connected to the control module  30  by conductors which travel through the third bore  22  between the outside face  15  and the inside face  14  of the door  12 . The control module  30  is electrically connected to the lockset  16   a  by conductors  26   b  which are routed through the slot  28 , fourth bore  24  and partial bore  29 . The outer escutcheon assembly  50  contains the electrically actuated components of the lockset  16   a . The outer escutcheon assembly  50  also covers partial bore  29 . 
     Installation of the modular electronic door security system is simplified when the door is hollow, such as a hollow steel door. Preparation of a hollow door consists of creating through bore  22  and partial bore  29  in addition to the bores  20 ,  21  necessary for installation of the lockset  16 . Electrical connections between component locations are easily made through the hollow space within the door  12 . Advantageously, conductors routed through the interior of the door cannot be tampered with and do not mar the appearance of the door. 
     Communication between the components of the modular electronic door security system may also be accomplished using wireless technology. Wireless communication links eliminate the need for much of the boring required for wired installations. FIG. 12A illustrates an alternative embodiment of the modular electronic door security system incorporating wireless communication technology. Known methods of short distance wireless communication include optical infra-red, optical laser or radio frequency (RF) systems. Either the input device  40  or the control module  30  may be provided with an optical or radio transmitter  34   a ,  32   a . The inner or outer escutcheon may be provided with a compatible optical or radio receiver  34   b ,  32   b . The communication link  34   c ,  32   c  established between the location of the input/control components and the location of the electro-mechanical lockset allows actuation of the lockset in the same manner as a conductor. 
     It is possible to combine the input and control functions in one module (not illustrated). A combined input/control module may not require that bore  22  pass through the inside face  14  of the door  12 . Alternatively, the control module of the system may be installed within the interior space of a hollow door, in which case an opening may be made on the inside door face to provide access to the control module for necessary service (battery changes, programming, etc.). A combined input/control module may eliminate the need for access to the module through the inside face of the door altogether. Necessary service may be performed from the unsecured side of the door, provided that measures are taken to prevent unauthorized access to sensitive portions of the control module. 
     For some installations, it may be necessary to connect the modular electronic door security system to facility based power or security systems. FIGS. 2A,  2 C and  13  illustrate bore  25 , which connects the conductor pathways in the door to the hinge edge  44  of the door  12 . It is known in the art to connect door mounted components to facility-based systems through the hinge edge of the door. 
     While the modular electronic door security system  10  makes it possible to install the input and control modules anywhere on the surface of a door  12 , the invention is particularly directed to installation of the input and control modules in a central portion of the door. As used herein, central portion refers to an area of the face of the door more than ⅛th of the width of the door from both the latch edge  41  and the hinge edge  44  and more than ¼th of the height of the door from both the top edge  46  and the bottom edge  48 . The central portion  60  of the door is illustrated by the broken line rectangle on FIG.  13 . 
     Inputs from the input device  40  are transmitted to the control module  30  by conductors  26   a  as illustrated in FIG.  12 . The control module  30  comprises a micro-processor  30   a , memory  30   b , a battery or other form of power supply  30   c  and a driver  30   d  for the electro-mechanical lockset. Received inputs are compared by the microprocessor  30   a  to valid inputs stored in memory  30   b . Upon detection of a valid input, the micro-processor  30   a  generates a signal to the driver to actuate the micro-motor in the electro-mechanical lockset  16 . Only upon detection of a valid input will the control module  30  activate the lockset  16 . 
     The electro-mechanical lock set  16  incorporates a clutch mechanism in the outer escutcheon assembly  50 . FIG. 7 is an end view of the outer escutcheon assembly  50 . The handle  18  will be mounted to the hub  52  which protrudes from the outer escutcheon assembly  50 . With reference to FIG. 8, the hub  52  has a notch  54  for reception of an engagement pin  56 . The engagement pin  56  carried by an interface cam  66  and is biased toward a disengaged position by engagement pin spring  55 . The interface cam  66  is mechanically linked to other parts of the lockset so that rotation of the interface cam  66  will retract the latch and open the door. When the engagement pin  56  is in a disengaged position, the hub  52  turns independently of the interface cam. 
     FIG. 9 illustrates the internal components of the outer escutcheon assembly  50  in a locked configuration. In a locked configuration, the key cylinder  68  is installed and restrains the override spring  70  in a non-override position. The micro motor  58  is not activated and the position of the moving wall  62  allows the spring biased engagement pin  56  to remain in the disengaged position. Movement of the hub  52  will have no effect on the interface cam  66  and the rest of the lockset when the internal components are positioned as shown in FIG.  9 . 
     FIG. 10 illustrates the internal components of the outer escutcheon assembly  50  in an unlocked configuration. The micro motor  58  has been activated, rotating the drive shaft  65  and drive spring  64  to shift the moving wall  62  and force the engagement pin  56  into engagement with the notch  54  in the hub  52 . The hub  52  and interface cam  66  are thus mechanically linked and rotation of the hub  52  results in a corresponding rotation of the interface cam  66 . When the moving wall  62  and engagement pin  56  are positioned as illustrated in FIG. 10, the door is in an unlocked configuration, i.e., the hub  52  and the interface cam are mechanically linked and movement of the outside handle  18  will result in retraction of the latch  17  from its projected, latched position. 
     The embodiment of the outer escutcheon assembly  50  illustrated in FIGS. 8-11, incorporates a novel override arrangement. An override spring  70  is restrained in a non-override position by the presence of a removable key cylinder  68 . The key cylinder includes a retractable lug  69  which projects to retain the key cylinder  68  in place within a receiver  72  in the outer escutcheon assembly  50 . 
     FIG. 11 illustrates the components of the outer escutcheon assembly  50  in an override configuration. In this configuration the key cylinder  68  is removed from its receiver. When the key cylinder  68  is removed the unrestrained key override spring  70  exerts sufficient force on the moving wall  62  to overcome the countervailing forces of the engagement pin spring  55  and drive spring  64 . As a result, the moving wall  62  shifts toward the unlocked position and urges engagement pin  56  into engagement with the hub  52 . In this manner, upon failure of the electronic or electro-mechanical portions of the modular electronic door security system  10 , access to secured areas is still possible. 
     FIG. 11A illustrates an alternative embodiment of the override arrangement in the non-override position. In the alternative embodiment, the override spring  70  is replaced by a rigid link  70   a  having a pivot  70   c  and bias spring  70   b . Bias spring  70   b  urges the link  70   a  toward the override position. The key cylinder  68  is installed, restraining the link  70   a  from achieving the override position. 
     Many alternative input devices may be utilized to control access through the door  12 . FIG. 5A illustrates a combination input device  40   a  which incorporates a card reader, key pad and contact activatable dataport. FIG. 5B illustrates a modular electronic door security system  10  incorporating an input device  40   b  consisting of a card reader. FIG. 6 illustrates a modular electronic door security system  10  incorporating an input device  40   c  consisting of a key pad. Other possible input devices may include smart cards, palm scanners, retina scanners, voice recognition systems, and the like. FIGS. 5A,  5 B and  6  also illustrate that the modular electronic door security system is compatible with standard cylindrical latch locksets  16   a , locksets including mortise deadbolts  16   b  suitable for the hospitality industry, and mortise latch locksets  16   c.    
     While preferred embodiments of the foregoing invention have been set forth for purposes of illustration, the foregoing descriptions should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.

Summary:
A modular electronic door security system includes an input device, a control module and an electro-mechanical lockset mounted to a door configured to facilitate electrical interconnections interiorly of the door. The input device and/or control module may be mounted in a user defined location on the surface of the door. An optional override mechanism allows access to secured areas in the event of system failure or emergency.