Patent Abstract:
An object sensing arrangement is provided in combination with a door that is adapted to be supported for movement from one of an open position and a closed position to the other of the open and closed positions without moving in a first direction in which earth gravitational force acts upon the door. The object sensing arrangement is positioned relative to the door for sensing presence of an object adjacent an end surface of the door that faces in a second direction opposite the first direction. The object sensing arrangement further provides signaling to indicate that object presence is sensed.

Full Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application contains subject matter related to subject matter contained in co-pending U.S. Ser. No. 12/459,289 (docket DCS-1) filed on Jun. 30, 2009 and incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present work relates generally to door monitoring and, more particularly, to monitoring a door to detect applied forces. 
       BACKGROUND 
       [0003]    Suicides among patients in mental health treatment facilities and other types of confinement facilities are all too common occurrences. In some instances, the patient or detainee rigs an elongate flexible member, for example a strip of a bed sheet, blanket, curtain, etc., over a door (often the door of the patient or detainee&#39;s quarters) in order to hang himself. As an example, the patient/detainee may secure one end of the flexible elongate member to a door handle on one side of the door, and sling the flexible elongate member across the top of the door such that it depends downwardly along the other side of the door. Then, with the door either open or closed, the patient/detainee secures the free end of the flexible elongate member around his neck. The flexible elongate member, rigged generally as described above and secured around the neck of the patient/detainee, supports the body of the patient/detainee above the floor, thereby permitting the patient/detainee to hang himself by the neck until dead. 
         [0004]    It is desirable in view of the foregoing to provide for detecting, and signaling an alarm, when a patient/detainee attempts suicide in a manner such as described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  illustrates a wall construction according to exemplary embodiments of the present work. 
           [0006]      FIG. 2  illustrates a portion of  FIG. 1  in more detail. 
           [0007]      FIG. 3  illustrates a portion of section A-A in  FIG. 1 . 
           [0008]      FIG. 4  illustrates a hinge structure according to exemplary embodiments of the present work. 
           [0009]      FIG. 5  is similar to  FIG. 2 , and illustrates a portion of a door assembly according to further exemplary embodiments of the present work. 
           [0010]      FIG. 6  illustrates a solid core door according to exemplary embodiments of the present work. 
           [0011]      FIG. 7  illustrates exemplary embodiments that use object sensing arrangements to detect the presence of a ligature rigged over the top of a door. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]      FIG. 1  illustrates a wall construction according to exemplary embodiments of the present work. A doorframe  15  defines a doorway  16  in a wall  12 . A door assembly  19  is cooperable with the doorway  16 . The door assembly  19  includes a hinge structure  13  affixed to a door  11 . The hinge structure  13  is also affixed to the doorframe  15  to mount the door  11  to the wall  12 . The wall  12  and the hinge structure  13  support the door  11  for angular, swinging movement about a generally vertically oriented hinge axis H. The movement of the door  11 , indicated at M, permits it to assume an open position as illustrated, and a closed position wherein the door occupies and closes the doorway  16 . The door assembly  19  also includes pressure sensors  14  secured to upper portions of opposite surfaces of the door  11  and adapted to detect the presence of forces other than the force of gravity G that act on the door in a direction parallel to the direction of the force of gravity. 
         [0013]      FIG. 2  illustrates a portion D of the door  11  of  FIG. 1 . As can be seen from  FIGS. 1 and 2 , the sensors  14  extend along the upper portion of opposite surfaces  22  and  23  of the door  11 , across substantially the entire width of the door. In some embodiments, the sensors  14  are secured to the door  11  by a suitable adhesive material. Pressure sensors such as those shown at  14  are well known in the art and readily commercially available. The pressure sensors  14  sense force(s) applied to them, and produce signaling to indicate the presence of the applied force(s). 
         [0014]    The sensors  14 , as positioned on the surfaces  22  and  23 , are capable of detecting the presence of a force applied to the top surface  21  of the door in a direction generally parallel to the force of gravity G. If, for example, a flexible elongate member is rigged across the top surface  21  of the door  11  so as to support the weight of a person&#39;s body (as described above), the body weight will cause the elongate member, as it depends downwardly from the top surface  21  under tension, to apply force against at least one of the pressure sensors  14 . The sensor(s) will detect the presence of the applied force, and produce signaling to indicate the presence of the force. The sensors  14  are capable of such force detection and signaling while the door  11  is in either the open position or the closed position. Also, and as described in detail hereinafter, the wall construction of  FIG. 1  is capable of conducting the signaling from the location of the sensor  14  to a location in the wall  12  for ultimate routing to a control system, whether the door  11  is in the open position or the closed position. 
         [0015]      FIG. 3  illustrates a portion of section A-A in  FIG. 1 , namely, the area around the hinge structure  13 . The door  11  of  FIG. 3  is a hollow core door. Power and signal lines for the sensors  14  are provided in a cable  32  (a ribbon cable in some embodiments) of electrical wires. The cable  32  passes through an opening  34  that extends through a wall portion  12 B and a door jamb portion  12 A of the wall  12 . A conduit  33  disposed within the opening  34  houses the portion of cable  32  that passes through the wall  12 . The cable  32  passes through the conduit  33  to a control system  35 . At its other end, the cable  32  emerges from the opening  34  and traverses openings in the hinge structure  13  and the door  11  to reach the interior space  36  of the door  11 . There, the signal and power lines are separated, as shown at  31 , and are connected to the sensors  14  via suitable openings (not explicitly shown) in the upper portions of the door surfaces  22  and  23  covered by the sensors. 
         [0016]    Hinge structures with openings for permitting electrical cabling to traverse the hinge are known in the art. Various embodiments use various ones of those known structures.  FIG. 4  illustrates an example of hinge structure  13  according to some embodiments of the present work. The hinge structure  13  of  FIG. 4  includes an elongate metal door portion  41  having a flange  408  for attachment to the door  11  by screws or other suitable fasteners (not shown), and an elongate metal frame portion  42  having a flange  401  for attachment to the door frame  15  by screws or other suitable fasteners (not shown). The door and frame portions  41  and  42  are approximately as long as the height of the door  11 . The door and frame portions  41  and  42  have respective flanges  400  and  409  with respective gear structures  40  and  49  that are held in mutual engagement by an elongate joint cover  48 , forming a hinged joint between the door and frame portions. A cover  47  covers the door portion  41 . When the door  11  is in the closed position, the flange  401  of the frame portion  42  is received in a notched section  407  between the flanges  408  and  409  of the door portion  41 . Hinge structures of this general construction are known in the art. 
         [0017]    The door portion  41  has an opening  43  provided in flange  408 , and a slot  44  provided in the notched section  407 . The frame portion  42  has an opening  45  provided in flange  401 . The openings  43  and  45 , together with the slot  44 , permit the cable  32  to pass from the wall  12  through the hinge structure  13  and into the interior space  36  of the door  11  (see also  FIG. 3 ). 
         [0018]    Referring again to  FIG. 3 , the opening  45  substantially coincides with the opening  34  in the wall  12 , and the opening  43  substantially coincides with an opening  35  in the door  11  to permit the cable  32  to pass into the interior space  36  of the door  11 . In some embodiments, the slot  44  is filled with putty to protect the (otherwise exposed) portion of the cable  32  that is disposed within the slot  44 . 
         [0019]    In various embodiments, the control system  35  includes various combinations of conventional devices (local and/or remote relative to the door) such as audible and visible alarms, visual displays, manually operated switches, electrical power sources, and sensor configuration/control interfaces. In some embodiments, the control system  35  provides operating power for the sensors  14 , receives and detects pressure-indicative signaling from the sensors, and responds appropriately (e.g., activates an alarm indication, etc.), 
         [0020]      FIG. 5  illustrates alternate embodiments wherein the sensors  14  are provided on and extend substantially the entire length of the top surface  21  of door  11 . Such embodiments require appropriate clearance between the sensors  14  and the door frame  15  to prevent false alarms when the door  11  is in the closed position. 
         [0021]      FIG. 6  illustrates embodiments that use a solid door  11 ′. A vertical bore  61  defines interior space in the door  11 ′ for the cable  32  and wires  31  (see also  FIG. 3 ). An opening  62  permits the cable  32  to pass from the door  11 ′ into the opening  43  of the door portion  41  of hinge structure  13  (see also  FIG. 4 ). Some embodiments provide horizontal bores  65  that permit the sensors  14  to be connected in series by wiring that extends between the sensors, passing through the horizontal bores  65  and the vertical bore  64 . The series sensor connection may alternatively be provided via a vertical bore  63  and horizontal bores  64  provided in door  11 ′ near its free end  66 . 
         [0022]    A series sensor connection may be achieved in hollow core door embodiments by providing, in the portions of surfaces  22  and  23  covered by the sensors  14  (see also  FIGS. 1-3 ), holes suitable for passing the wiring that connects the sensors. Some embodiments locate those holes near the free end  17  of the door  11 . 
         [0023]    Some embodiments provide an object sensing arrangement for sensing presence of an object adjacent the top surface of the door  11  (such as a ligature rigged over the door).  FIG. 7  shows an object sensing arrangement including a source of electromagnetic radiation (one of  71  and  72 ) and a receiver/detector of electromagnetic radiation (the other of  71  and  72 ). These components  71  and  72  are mounted on the wall  12  closely adjacent the upper corners of the doorway opening  16  (see also  FIG. 1 ). A beam of electromagnetic radiation emitted by the source is normally received at the receiver. However, if an object is present in the path of the beam, this interruption of the beam is detected by the receiver. The receiver provides signaling (via a suitable conductor within the wall  12 ) indicating to the control system  35  of  FIG. 3  that an object has interrupted the beam. 
         [0024]    As is evident from  FIG. 7 , the components  71  and  72  are positioned relative to the door  11  such that the beam travels from source to receiver in a direction generally parallel to the front surface of the door. In some embodiments, the path of the beam overlies and extends generally parallel to the top surface  73  of the door  11 , just below the upper edge of the doorway opening  16 . An object that interrupts the beam will be detected. 
         [0025]    As shown in  FIG. 7 , some embodiments combine the object sensing arrangement  71 / 72  with the  FIG. 2  arrangement of pressure sensors  14 . Other embodiments combine the object sensing arrangement  71 / 72  with the  FIG. 5  arrangement of pressure sensors  14  (not explicitly shown in  FIG. 7 ). Still other embodiments use the object sensing arrangement  71 / 72  but omit pressure sensors. In some embodiments, the object sensing arrangement  71 / 72  is implemented using a dot LED source and a photodiode receiver, such as is commercially available, for example, from SUNX Limited of Kasugai, Aichi, Japan (part number EX23PN). 
         [0026]      FIG. 8  illustrates embodiments wherein the components of object sensing arrangement  71 / 72  are mounted on the front surface of the door  11  adjacent the top of the door. In some embodiments, the path of the beam extends from source to receiver adjacent and generally parallel to the front surface of the door  11 , just below the top surface of the door. An object that interrupts the beam will be detected. As shown by broken line in  FIG. 8 , some embodiments combine the door-mounted object sensing arrangement  71 / 72  with the  FIG. 2  arrangement of pressure sensors  14 , and other embodiments combine the door-mounted object sensing arrangement  71 / 72  with the  FIG. 5  arrangement of pressure sensors  14 . Still other embodiments use the door-mounted object sensing arrangement  71 / 72  but omit pressure sensors. In some embodiments, electrically conductive power and signaling connections to the object sensing arrangement  71 / 72  traverse the hinge structure  13  of  FIG. 3  within the cable  32 . 
         [0027]    In embodiments that combine an object sensing arrangement  71 / 72  such as shown in  FIG. 7  or  8  with the  FIG. 2  pressure sensor arrangement, it will of course be recognized that all components are suitably positioned relative to one another such that the pressure sensors  14  do not interrupt the beam between source and receiver. 
         [0028]    Although exemplary embodiments of the present work have been described above in detail, this does not limit the scope of the present work, which can be practiced in a variety of embodiments.

Technology Classification (CPC): 4