Abstract:
An institutional door lock mechanism for retrofitting existing installations with a remotely controllable/monitorable door lock and open/close position indicator is described. A hollow vertical door strike jamb extends along an outside surface of the door frame opposite a hollow vertical columnar striker plate mechanism mounted on a fronting plate of the door. A hollow vertical housing also on the fronting plate contains a first component part of a proximity/alignment detection mechanism including a magnetic reed switch. The door strike jamb is configured as a vertical riser for housing a wiring harness for the catch-extension/retraction mechanism and for the proximity/alignment detection mechanism. The catch-extension/retraction mechanism includes a motor for extending/retracting the catch, the motor being operable by a securely coded manual key placed adjacent a switch mechanism or within a keyway operatively coupled with the switch mechanism. The catch-extension/retraction mechanism operates in a fail-safe lock-down mode of operation in the event of power interruption or failure.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 60/931,181, filed on 21 May 2007 and entitled. INSTITUTIONAL DOOR LOCK MECHANISM, the contents of which are hereby incorporated herein in their entirety by this reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates generally to the field of access and security. More particularly, it concerns a unique, retrofit-able door locking assembly for institutional use. 
         [0003]    Thousands of lock-down facilities across the country are equipped with manual key locks on doors for access to and from secure areas, e.g. prison and/or jail cells or blocks. Security, safety and cost concerns have driven regulations regarding more modern locking systems that are remotely operable, e.g. from a guard station, and manually operable with a key, e.g. by a guard or jailer. Remote door-position monitoring is desirable in such institutional settings to ensure that every door is in its proper open or closed position at all times for both security and safety concerns of both inmates and staff. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a front elevation of a door equipped with a door lock and position indicator mechanism in accordance with one embodiment of the invention. 
           [0005]      FIG. 2  is an enlarged detail of the lock and position indicator mechanism of  FIG. 1 . 
           [0006]      FIG. 3  is a sectional view taken along the lines  3 - 3  of  FIG. 2 . 
           [0007]      FIG. 4  is a sectional view taken along the lines  4 - 4  of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0008]    The invention in accordance with a preferred embodiment involves a hollow, auxiliary door strike jamb, a door-mounted plate and a lock mechanism operable to securely couple the door to the auxiliary door strike jamb. The auxiliary door strike jamb is securely and unyieldably secured, as by welding, to an existing, typically institutional, door jamb (e.g. to a jail or prison cell), with the weld seams preferably finished with auto body filler, sanded smooth and painted. The unique structure of the auxiliary door strike jamb and the door-mounted plate fixed with a pull handle enables easy retrofitting of an electromechanical door lock and door position indicator (DPS) mechanism for securely, selectively operating and monitoring a conventional sliding bolt-type lock and associated door. The auxiliary door strike jamb&#39;s hollow interior (which door strike jamb may be referred to herein as a “riser”) provides an electrical conduit to accommodate a wiring harness for the required electrical connections. 
         [0009]    There are many suitable manufacturers of the electromechanical components that form a part of the invention. For example, the DPS mechanism is available from a variety of sources and the magnetic reed switch that forms a part thereof is available from DETEX (e.g. model MS-2049F or alternative) in a twenty-four volt direct current (24VDC) version. The electromechanical lock is available from Folger Southern, Brinks, and Airteq. Those of skill in the art will appreciate that any suitable electromechanical devices can be used that accomplish the security and monitoring functions provided by the invention. 
         [0010]      FIG. 1  is a front elevation of the invented door lock mechanism  10  installed or retrofitted on a left-side hinged metal cell door  12  (those of skill in the art will appreciate that a right-side or left-handed door installation would simply be a mirror image). Door  12  and its wall and frame  14  will be understood to be conventional, and will not be described in detail herein. Suffice it to say that door  12  of conventional manual key lock manufacture has had all of its old manual key lock mechanism removed from both the original door  12  and from the original and typically integral door strike wall and frame  14  (refer briefly to  FIGS. 3 and 4 ). 
         [0011]    Door lock mechanism  10  includes a retrofit pull handle assembly  16  including a detention wire pull  18  and a door-mounted steel face plate receiver  20 , the wire pull securely mounted on the face plate. Face plate  20  includes a forward or outer hollow vertical column  22  preferably integrally formed therewith for mounting therein a first component of a magnetic reed switch door position indicator (DPS) mechanism  24 , the column including a hollow recess and an aperture for securely receiving therein a catch extendable from an auxiliary door strike jamb or riser  26 . 
         [0012]    Door lock mechanism  10  further includes a second component of the magnetic reed switch DPS mechanism  24 , mounted within the hollow interior of auxiliary door strike jamb  26  securely aligned with the first component thereof, as shown. Those of skill in the art will appreciate that the first and second components of magnetic reed switch DPS mechanism  24  cooperate with one another to indicate whether door  12  is positioned relative to the door strike wall and frame  14  in or out of sufficiently precise alignment to indicate that the door is unsecured of secured (open or closed), respectively. Those of skill also will appreciate that DPS mechanism  24  can be implemented in accordance with the invention in any suitable manner and with any suitable means not limited to the use of a magnetic reed switch. For example, an alternative electronic or mechanical proximity detection mechanism can be used, within the spirit and scope of the invention. 
         [0013]    Door lock mechanism  10  further includes an electromechanical lock mechanism  28  that includes a catch-extension/retraction mechanism  32  including an extendable/retractable catch (tongue)  34  operated by a switch mechanism (not separately shown), the former mounted within the hollow interior of auxiliary door strike jamb  26  typically beneath or at a lower elevation than that of DPS mechanism  24 , as shown and the latter extendable therefrom and retractable thereinto. Those of skill in the art will appreciate that catch-extension/retraction mechanism  32  can be operated remotely or manually opened (this latter being required in most jurisdictions by safety code. For example, an authorized staff person can operate mechanism  32  remotely from a guard station or, alternatively, a jail or prison guard can operate mechanism  32  by key while standing outside the jail or prison cell, as described above). The DPS mechanism  24  can be remotely interrogated to determine whether the door is secure as indicated by the door&#39;s position relative to the jail or prison cell&#39;s door strike jamb. (Typically, the DPS mechanism reports via input/output (I/O) signaling to a program logic controller (PLC) within a base detention monitoring system, although such forms no part of the present invention.) 
         [0014]    Those of skill in the art will appreciate that auxiliary door strike jamb  26  is referred to herein as a riser because its contiguous, hollow, interior channel provides a conduit for one or more electrical wiring harnesses that supply electricity to or from the electromechanical components of the door&#39;s invented electromechanical lock door strike assembly and/or its door position indicator. Similarly, an opened/closed signal within DPS mechanism  24  can be powered by a similar wiring harness and signals conveyed therefrom up through riser  26  (which, as suggested in  FIG. 1 , can extend terminate at the ceiling or in a non-accessible space thereabove containing a junction box for power and signal feed/monitoring). Similarly, a wiring harness can be used to power the switch, relay, motor, receiver, and/or other mechanism(s) within electromechanical lock mechanism  28 . 
         [0015]    Thus the riser provides for the wiring of the invented institutional door locking assembly for a hardwired mode of operation. The lock remains operational under powered mode and fail-secure under un-powered mode or under power failure. Key operation of the lock in un-powered mode or in power failure will still operate the locking assembly. 
         [0016]    Turning collectively now to  FIGS. 2 through 4 , further details of invented door lock mechanism  10  are described. Face plate  20  can be seen to be dimensioned in accordance with one embodiment of the invention as follows. The steel face plate is approximately ¼ inch (¼″) thick and is approximately 19⅛″ high by approximately 6″ wide (including approximately 1″ wide vertical column  22  preferably integrally formed therewith). Face plate  20  in accordance with one embodiment of the invention is cast but within the spirit and scope of the invention it may be made by any suitable process such as extrusion, die-stamping and/or die-cutting, etc. that is compatible with required security, durability, and overall integrity of the door lock mechanism. 
         [0017]    Also in accordance with one embodiment of the invention, face plate  20  is backed by a backing plate  36  (refer to  FIG. 3 ) of similar structure and dimension, but without the integrally formed vertical column  22 . Thus, in accordance with one embodiment of the invention, face plate  20  and backing plate  36  are mounted using plural (e.g. six or other suitable number of) countersunk security fasteners  38  to one another on opposite surfaces of door  12 . Those of skill in the art will appreciate that the security fasteners can take any suitable form, e.g. threaded collar/threaded post pairs, of any durable and uncompromise-able structure. For example, heavy gauge stainless steel countersink threaded male/female members the heads of which have pin torx bit patterns can be used. Those of skill will appreciate that similar or dissimilar but suitable fasteners and clips are utilized within auxiliary door jamb or riser  26  securely to mount and dress the electromechanical components and wiring harnesses. 
         [0018]    Those of skill in the art will appreciate that the face and backing plates are substantially aligned with one another and are positioned to cover the region of the original door lock pocket bearing the manual key hole. In this installation manner, the retrofit of the original door  12  to be equipped with invented door lock mechanism  10  is substantially invisible from the interior and exterior of the jail or prison cell, and the original door&#39;s and jail or prison facility&#39;s aesthetic qualities are maintained while the facility&#39;s security and safety are enhanced. 
         [0019]    As can be seen from  FIGS. 3 and 4 , door strike jamb or riser  26  can be made of 2″×2″, 2″×2½″, or 2″×3″ fourteen gauge ( 14 G) steel, extruded or otherwise manufactured in a preferably rectangular tubular form. Those of skill in the art will appreciate the high structural integrity and durability of such a structure, and also will appreciate that the hollow columnar region enclosed therein is configured securely to mount the second component of DPS mechanism  24  as well as the electromechanical lock mechanism  28  in proper horizontal alignment with their corresponding and cooperative features within vertical column  22 . The riser in accordance with the invention is made to be compatible with one or more lock manufacturer&#39;s wiring harness configurations. 
         [0020]    Those of skill in the art will appreciate that backing plate  36  can be provided without a handle or with a simple finger pull, as illustrated by a rounded trapezoid in  FIGS. 3 and 4 . Those of skill in the art also will appreciate that, in accordance with one embodiment of the invention, vertical column  22  and auxiliary door strike jamb or riser  26  are dimensioned depth-wise such that their exterior surfaces are substantially flush with one another. It will be appreciated that within the spirit and scope of the invention, top and bottom horizontally extending auxiliary door frame members (shown in  FIG. 1 ) can be added and mitered at the two right corners for smooth joinder with auxiliary door strike jamb or riser  26 , thereby rendering the retrofitted door more useful as conduits for wiring harnesses as well as improving the aesthetic match and fit of the retrofitted door  12  and wall and frame  14 . 
         [0021]    It will be understood that the present invention is not limited to the method or detail of construction, fabrication, material, application or use described and illustrated herein. Indeed, any suitable variation of fabrication, use, or application is contemplated as an alternative embodiment, and thus is within the spirit and scope, of the invention. 
         [0022]    From the foregoing, those of skill in the art will appreciate that several advantages of the present invention include the following. 
         [0023]    The present invention provides retrofit-ability into the large installed base of institutional doors of more secure and safe electromechanical locks. It provides simplicity and relatively low cost in such retrofit installations, with no modification to existing institutional walls, hardware or fixtures. It increases the ease of operation without compromising security or safety. Indeed, it enhances safety and security via added control and monitoring. Finally, it uses conventional electromechanical componentry and exiting doorjambs, frames and walls in such institutional settings. 
         [0024]    It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, method of manufacture, shape, size, or material which are not specified within the detailed written description or illustrations contained herein yet are considered apparent or obvious to one skilled in the art are within the scope of the present invention. 
         [0025]    Accordingly, while the present invention has been shown and described with reference to the foregoing embodiments of the invented apparatus, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. 
         [0026]    It will be understood that the present invention is not limited to the method or detail of construction, fabrication, material, application or use described and illustrated herein. Indeed, any suitable variation of fabrication, use, or application is contemplated as an alternative embodiment, and thus is within the spirit and scope, of the invention. 
         [0027]    It is further intended that any other embodiments of the present invention that result from any changes in application or method of use or operation, configuration, method of manufacture, shape, size, or material, which are not specified within the detailed written description or illustrations contained herein yet would be understood by one skilled in the art, are within the scope of the present invention. 
         [0028]    Finally, those of skill in the art will appreciate that the invented method, system and apparatus described and illustrated herein may be implemented in software, firmware or hardware, or any suitable combination thereof. Preferably, the method system and apparatus are implemented in a combination of the three, for purposes of low cost and flexibility. Thus, those of skill in the art will appreciate that embodiments of the methods and system of the invention may be implemented by a computer or microprocessor process in which instructions are executed, the instructions being stored for execution on a computer-readable medium and being executed by any suitable instruction processor. 
         [0029]    Accordingly, while the present invention has been shown and described with reference to the foregoing embodiments of the invented apparatus, it will be apparent to those skilled in the art that other changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.