Patent Publication Number: US-8534723-B2

Title: Conical shank anti-ligature releasable door lever

Description:
RELATED PATENT APPLICATION 
     This application claims priority under 35 U.S.C. §119, 120 based upon applicant&#39;s Provisional Patent Application Ser. No. 61/197,887, filing date of Oct. 31, 2008. 
    
    
     I. BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a serious problem where certain patients in behavioral health care facilities or psychiatric institutions try to commit suicide by hanging themselves with cords or other items looped over the handles or knobs of doors to their rooms. This invention relates to methods and apparatus seeking to prevent such attempted suicides. 
     2. Background and Prior Art 
     It is known that certain patients in institutions try to commit suicide by various different means. Reasons for such behavior are complex and not the subject of the present invention; however, significant numbers of attempts do occur, and significant numbers of patients are committed into these institutions for the very reason that they are known to be candidates for suicide attempts and these institutions are supposed to be environments for treatment of these and other problems and for prevention of patients from achieving suicide. 
     While the methods employed for the attempted suicides vary with the available environment and creativity of the patients, the present invention is concerned with attempts by hanging with a cord, belt or other item with the near or proximal portion of the cord wrapped around the door knob, lever or other handle of a door. The distal or remote end of the cord, belt or other item on the interior side of the door is formed into the suicidal noose and then either draped over the door to the far side door knob or handle, or, if short, the patient attempts suicide by dropping down to the floor from the doorknob, lever or other handle on either side of the door. 
     In typical psychiatric institutions the patients&#39; activities, as regards personal safety and behavior in general, are monitored carefully by staff; however, it is also common for patients to have private rooms with unlocked doors for them to come and go generally as they please. It is in these kinds of situations where a patient has periods of relative privacy and domain over his or her door, when a suicide attempt can be made without immediate awareness of institution staff and with enough time for the suicide to be successful before staff action can be taken. For various reasons there are surprisingly high numbers of attempted and successful suicides in psychiatric institutions that are not generally publicized or known, but administrators of these institutions are quite aware and concerned. The present invention addresses these tragedies and presents a practical apparatus believed to be able to significantly reduce the problem on a nationwide basis. 
     The present invention will be described herein as it functions within the known protocols of “Passage Mode” and “Classroom Mode” door lock systems. In Passage Mode the door lock is set so that a person can exit a room by pushing down on the interior side lever, and a person can enter the room by pushing down on the exterior side lever. In Classroom Mode the door lock is set differently so that a person inside the room can exit by pushing down on the lever; however, the lockset can be set to function by use of a lever, button, turn piece or key lock feature, in either (a) “Classroom (Locked) Mode” where pushing down on the exterior side lever will not open the door, to prevent patients from entering rooms without supervision, or (b) Classroom (Unlocked) mode which is like the above mentioned Passage Mode. These Passage and Classroom Mode protocols are continued in the present invention, as will be apparent herein and as are further illustrated in the attached Appendix A. 
     II. OBJECTS AND SUMMARY OF THE NEW INVENTION 
     A first object of the present invention is to provide a method and apparatus to counter-act suicide attempts and thus to reduce the incidence of successful suicides in psychiatric hospitals and mental health wards, particularly regarding suicide attempts by hanging with a cord draped by a patient over the door in his or her room, with the distal or remote end of the cord tied or otherwise secured to the door lever or door knob on the exterior side of the door. Classroom Mode (Locked) is used to prevent patients from entering rooms without supervision. This object similarly concerns counter-acting suicide attempts by a patient who attaches a cord to the lever on either side of the door and attempts suicide by applying the noose and dropping down to the floor. 
     A further object of this invention is to install on a patient&#39;s door a new “Anti-Ligature Lever Latch Lock” or “A4L”, which will be resistant to a patient&#39;s suicide attempts to use a cord or ligature draped over the door and tied to a door lever or turn piece on the exterior or interior side of the door. 
     An additional object is to provide a new A4L system that is ADA-compliant, namely compliant with the Americans With Disability Accessibility Guidelines (“ADAG”). 
     Another object is to provide an ADA-compliant A4L lock system designed to function with conventional mortise latch lock or cylindrical latch lock openings in widely used conventional doors, as applied to both newly constructed doors and as a retrofit applied to doors already installed and in use. 
     A still further object is to provide a lock set which functions optionally in Passage Mode, Classroom Mode (Locked), and Classroom Mode (Unlocked). One preferred mechanism for Classroom Mode (Locked) is a keyed mechanism to decouple the lever from the latch engagement mechanism so that pivoting the external side lever will not open the door. 
     A still further object, in regard to any suicide attempt where the ligature is tied to said handle, is to provide an ADA-compliant A4L lock system where the escutcheon is conical and the proximal or shank portion of the lever/handle is coupled to the escutcheon and continues the conical shape in a smooth junction that will enhance the tendency of a ligature to slide down the conical escutcheon and off the conical shank of the handle/lever. 
     An additional object herein is to provide an A4L lock body which is operable in both of the earlier described Passage and Classroom Modes, as explained herein. 
     (A) In Passage Mode the lever can be pushed downward against normal spring and friction resistance from both interior and exterior sides of the door to open said door, and the lever can be pivoted upward freely on both interior and exterior sides with no or only minimal resistance. A ligature tied to the exterior or interior side lever and pulled upward in a suicide attempt, will slide off the lever, since this lever pivots freely upward and downward and will offer no resistance to the ligature. 
     (B) In Classroom Mode (Locked) a person can push the interior side handle downward to leave the room; however, on the exterior side the lever will not retract the latch, so that a person cannot enter without release of the lock by someone inside or by a person outside with a release key. In this Classroom Mode an unauthorized person cannot enter the room, and that includes the patient when such patient is expected to be out the room and in a different specified location; however, in Classroom Mode (Locked) and (Unlocked) the interior and exterior levers are freely pivotable upward and downward, so that the anti-ligature protocol remains in force and protection against suicide by a cord tied to either lever is prevented, even though the door is in “Locked” Mode. 
     In one preferred embodiment the door&#39;s mortise lock body has special properties and/or the spindle has special properties to allow the lever to move freely at all times in Classroom Mode (Locked), where the spindle will not engage the latch in this mode. 
     A further object of the present invention is to provide for the door latch lock mechanism a lever having shape and contours to induce any ligature looped by a patient over or onto the lever to readily slide off and thus defeat the suicide by hanging attempt. To that end, the new lever comprises a truncated conical escutcheon part and a lever having a rounded or cap-like hub part and a transversely extending handle where a smooth uninterrupted surface is established along the side of the escutcheon and its function with the hub of the handle. 
     In a preferred embodiment, the base of the hub part has a circumferential edge essentially the same as the top edge of the escutcheon so that the function is smooth and uninterrupted on the outwardly exposed surfaces as illustrated in the appended drawings. A further feature in this preferred embodiment is the transverse extension of the handle of the top portion of the curved hub part to further establish the continuous exposed surface and junction of the hub and handle with absence of any projections or edges on which the ligature could catch. In the preferred embodiment shows the escutcheon having conical walls extending at an angle of about 55° from the plane of the base of the escutcheon and the hub curvature is generally hemispherical; however, variations of the incline of the escutcheon walls and if the hub curvature are possible, so long as the ligature will readily slide off the lever. 
     The present invention relates particularly to apparatus to automatically respond to attempted suicide and efforts to prevent it from succeeding. The apparatus described herein would immediately release the distal end of the cord and defeat the suicide attempt. 
     An additional object of the present invention is to provide the above described apparatus in a form that can be installed in standard doors used in a great many buildings and commonly used in psychiatric institutions, where installation can be easily done doors where standard preparations have been made in factories at time of initial manufacture and also as a retrofit onto existing doors wherever they may be. 
     It is a further object that such installation be simple and reasonable in cost and reliable in use. It is expected that the retrofit procedure will be quite easy, since common commercial and institution building doors have relatively standard size door preparation for the components of door levers, shanks and related mechanisms, which components can be readily removed and replaced with a substitute A4L subassembly. 
     An additional object is to provide apparatus that is non-obtrusive so that it will not attract the patient&#39;s attention, while still being esthetically attractive. 
     These and other advantages of the invention will be further understood and appreciated by those skilled in the art by reference to the following written specification, claims and appended drawings. 
     The present invention is further defined by the following structures: 
     1. A lever latch lock assembly installable in a door having interior and exterior sides, said assembly when installed in a door, comprising:
         a. a lock housing mounted in said door and having interior and exterior sides, said housing including a lock bolt movable along a first axis, a spindle extending along a second axis generally perpendicular to said first axis, said spindle extending outward at each of said interior and exterior sides of said housing and terminating in opposite ends, and a transmission which converts rotation of said spindle to axial motion said lock bolt,   b. a lever assembly attached to each of said spindle&#39;s ends and adapted to rotate said spindle, said lever assembly, including:
           (1) an escutcheon formed as a truncated generally conical cylinder having
               (i) a base of first diameter adapted to be situated closely adjacent one of said interior and exterior sides of said door and coaxial with said second axis,   (ii) a top end having a top edge opposite said base, said top end having a smaller diameter than said first diameter, and   (iii) a bore through which extends said spindle, and   
               (2) a lever including
               (i) a hub part having a generally hemispherical body with a generally round circumferential bottom edge substantially the same and adjacent said top end edge of said escutcheon and forming a smooth continuous junction therewith, and having a smooth convex top, and   (ii) an elongated handle part extending from one side of said escutcheon in a direction transverse of said second axis, said handle having a top part that extends as a smooth contiguous uninterrupted surface from said top of said hub.   
               
               

     2. A lever latch lock according to the structure “1” referred to above in Par. No. 0023 wherein said hub includes an axial recess extending in the direction of said bottom to said top thereof, and said spindle end is extended into said recess and keyed to rotate therewith. 
     3. A lever latch lock assembly according to the structure “1” referred to above in Par. No. 0023 wherein said hub part of said lever and said escutcheon have a common central axis. 
     4. A lever latch lock assembly according to the structure “1” referred to above in Par. No. 0023 wherein said escutcheon walls are inclined at about 55 degrees from the plane of the base of the escutcheon. 
     5. A lever latch lock assembly according to the structure “1” referred to above in Par. No. 0023 wherein said elongated handle part extends along a plane that defines an angle of about 91 degrees with said spindle axis and is inclined away from said door surface. 
     6. A lever latch lock assembly according to the structure “1” referred to above in Par. No. 0023 wherein said levers on said interior and exterior sides of said door can pivot from a generally horizontal rest position downward or upward, and said transmission is adapted so that either of said interior and exterior side levers can always freely pivot upwardly when pulled upward, and said transmission will engage said lock bolt to allow said door to open when said transmission is selectively directed to do so. 
     7. A lever latch lock assembly according to the structure “1” referred to above in Par. No. 0023 wherein said transmission means has: 
     (a) a Classroom Unlocked Mode where said exterior side lever is pivotable from said rest position downward which will move said lock bolt and open said door, and said lever is freely movable upward to an “anti ligature latch lock” release position, and 
     (b) a Classroom Locked Mode where said lever is pivotable from its rest position downward which will not open said door and is freely movable upward to said “anti ligature latch lock” release position. 
     8. A lock assembly according to the structure “7” immediately above wherein said transmission has a Passage Mode where movement of said lever downward in said Passage Mode lever on either interior or exterior side of said door will engage said transmission and move said bolt to open said door. 
     9. A lock assembly according to the structure “7” immediately above wherein movement of said lever upward in said Passage Mode will not move said bolt. 
     10. A lock assembly according to the structure “1” referred to above in Par. No. 0023 [see claim  2 ] wherein said transmission further comprises a switch movable between a first position Passage Mode which allows said lever to move downward without moving said bolt to its open state, and a second position for said Classroom Locked Mode which allows said lever to move downward to move said bolt to its open state. 
     11. A combination door and lever latch lock assembly installed therein, said door having interior and exterior sides, comprising:
         a. a lock housing mounted in said door and having interior and exterior sides adjacent and corresponding to said interior and exterior sides of said door, said housing including a lock bolt movable along a first axis, a spindle extending along a second axis generally perpendicular to said first axis, said spindle extending outward at each of said interior and exterior sides of said housing and terminating in opposite ends, and a transmission which converts rotation of said spindle to axial motion said lock bolt,   b. a lever assembly attached to each of said spindle&#39;s ends and adapted to rotate said spindle, said lever assembly, including:
           (1) an escutcheon formed as a truncated generally conical cylinder having
               (i) a base of first diameter adapted to be situated closely adjacent one of said interior and exterior sides of said door and coaxial with said second axis,   (ii) a top end having a top edge opposite said base, said top end having a smaller diameter than said first diameter, and   (iii) a bore through which extends said spindle, and   
               (2) a lever including
               (i) a hub part having a generally hemispherical body with a   generally round circumferential bottom edge substantially the same and adjacent said top end edge of said escutcheon and forming a smooth continuous junction therewith, and having a smooth convex top, and   (ii) an elongated handle part extending from one side of said escutcheon in a direction transverse of said second axis, said handle having a top part that extends as a smooth contiguous uninterrupted surface from said top of said hub.   
               
               

     12. A lever latch lock assembly installable in a door having interior and exterior sides, said assembly when installed in a door, comprising:
         a. a lock housing mounted in said door and having interior and exterior sides, said housing including a lock bolt movable along a first axis, a spindle extending from each side of said housing along a second axis generally perpendicular to said first axis, each of said spindles extending outward at each of said interior and exterior sides of said housing and terminating in opposite ends, and a transmission which selectively converts rotation of said spindles to axial motion said lock bolt,   b. a lever assembly attached to said end of each of said spindles and adapted to rotate said spindle, said lever assembly, including:
           (1) an escutcheon formed as a truncated generally conical cylinder having
               (i) a base of first diameter adapted to be situated closely adjacent one of said interior and exterior sides of said door and coaxial with said second axis,   (ii) a top end having a top edge opposite said base, said top end having a smaller diameter than said first diameter, and   (iii) a bore through which extends said spindle, and   
               (2) a lever including
               (i) a hub part having a generally hemispherical body with a generally round circumferential bottom edge substantially the same and adjacent said top end edge of said escutcheon and forming a smooth continuous junction therewith, and having a smooth convex top, and   (ii) an elongated handle part extending from one side of said escutcheon in a direction transverse of said second axis, said handle having a top part that extends as a smooth contiguous uninterrupted surface from said top of said hub.   
               
               

    
    
     
       III. BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a fragmentary front elevation view of a door mounted in a door frame with the new conical shank anti-ligature door lever lock, 
         FIG. 1A  is a fragmentary front perspective view of a ligature looped about the lever on a patient&#39;s door and then slipping off when suicide is attempted, 
         FIG. 2  is a fragmentary end elevation view in section taken along line  2 - 2  in  FIG. 1 , showing the ligature for use in an attempted suicide, 
         FIG. 3  is a top plan view in section taken along line  3 - 3  in  FIG. 1 , 
         FIG. 4  is a fragmentary front perspective view of the door and conical shank anti-ligature door lever, 
         FIGS. 5-8  are fragmentary front elevation views of the door and lock of  FIG. 1 , showing how the distal end of a ligature will slide off the exterior side lever of the new A4L as the distal end of the ligature is pulled upward, 
         FIG. 9  is a fragmentary enlarged elevation view in section taken along line  9 - 9  in  FIG. 3  showing the distal end of the ligature looped over or tied about the lever in its horizontal position, 
         FIG. 10  is a view similar to  FIG. 9  showing the lever in its upward position with the distal end of the ligature slipping off of the lever, 
         FIG. 11  is a fragmentary elevation view partially in section taken along line  11 - 11  in  FIG. 3 , showing the mechanism for switching the spindle collar to left-side Position A, 
         FIG. 12  is a fragmentary sectional view taken along line  12 - 12 , 
         FIG. 13  is a fragmentary elevation view partially in section taken along line  11 - 11  in  FIG. 3 , showing the mechanism for switching the spindle collar to right-side Position B, 
         FIG. 14  is a fragmentary sectional view taken along line  14 - 14  in  FIG. 13 , 
         FIG. 15  is a fragmentary end elevation view in section of another preferred embodiment of the present invention showing two separate coaxial spindle segments for the inside and outside levers respectively, 
         FIG. 16  is a fragmentary view of the central portion of  FIG. 15  with the collar shown shifted to the right, 
         FIG. 17  is a fragmentary side elevation view in section taken along line  17 - 17  in  FIG. 15  showing a cam driven by the spindle for actuating the locking bolt, 
         FIG. 18  is a top plan view in section of a preferred lever and truncated conical escutcheon, 
         FIG. 19  is a top plan view in section of the lever alone seen in  FIG. 18 , 
         FIG. 20  is a top plan view in section of the escutcheon alone seen in  FIG. 18 , and 
         FIG. 21  is a perspective view of the door lock coupling or transmission mechanism of  FIGS. 11-17 . 
     
    
    
     While the invention has been described in conjunction with several embodiments, it is to be understood that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, this invention is intended to embrace all such alternatives, modifications, and variations which fall within the spirit and scope of the appended claims. 
     IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1-10  illustrate the new A4L System  10  in operation on a conventional door  12  that is pivotally mounted in door frame  14 , with bolt  16  engagable in strike  18  in said door frame. One principal component of this A4L System is the conical escutcheon  10 A and lever  11  combination. In an attempted suicide a patient would extend a ligature  20  over the top of the door  12 , couple the ligature&#39;s distal end  20 A to lever  11  on the exterior side  12 B of door  12 , and form the ligature&#39;s proximal end  20 B into a noose that hangs down the interior side  12 A of door  12 . 
     The present invention is designed to defeat such an attempted suicide with an automatic decoupling and release of the distal end  20 A of the ligature  20  from the exterior side door lever  10 A,  11 ,  11 A when suicide is attempted on the interior side. The invention further includes an optional keyed operation to alter the door latch mechanism from Classroom (Locked) to Classroom (Unlocked) Mode, although the Lever in both modes the Anti-Ligature Release arrangement is maintained. 
     The Anti-Ligature Release System 
       FIGS. 1-4  show the first stage of a ligature suicide attempt where the distal end  20 A of ligature  20  has been tied or looped about the new lever construction formed of a rounded lever hub  11 A, a conical escutcheon  10 A and lever  11  on the exterior side  12 B of door  12 .  FIG. 2  shows proximal end  20 B of the ligature poised by a patient for the suicide attempt. 
       FIG. 5  shows the ligature&#39;s distal end  20 A looped over lever and hub  11 ,  11 A with ligature  20  beginning to be pulled upward by the force of the patient&#39;s body weight on the interior side, the force indicated by arrow  21 .  FIG. 6  shows, with arrow  22 , lever  11  beginning to pivot upward as force  21  continues to pull upward which drags the lower loop part  20 A of ligature  20  against the curved or conical surface of hub  11 A, such that the loop  20 A starts to slip off hub  11 A and onto lever  11 . 
       FIG. 7  shows lever  11  pivoted still further in the upward and clockwise direction of arrow  22  as force indicated by arrow  21  continues, and loop  20 A has slid toward the end of lever  11 .  FIG. 8  shows that loop  20 A has slid completely off lever  11 , and obviously at this point with the proximal end  20 B still about the patient&#39;s neck; the patient&#39;s body will have fallen to the floor, and the hanging has been stopped.  FIGS. 9 and 10  further illustrate lever  11  and its internal coupling, corresponding to lever positions in  FIGS. 5 and 8  respectively. 
       FIG. 1A  illustrates a variation of a suicide attempt where the ligature is coupled to the lever on the interior side of the door of the patient&#39;s room, with ligature  19  looped over the lever  19 A; the dashed line  19 B illustrates how the ligature  19  slips off the lever when suicide is attempted. 
       FIGS. 3 ,  4  and  6  show clearly how the outer tapered surface of hub  11 A meets seamlessly with the adjacent conical escutcheon  10 A. Due to the continuous curve of escutcheon  10 A and hub  11 , the looped distal end  20 A of ligature  20  will initially slide from the escutcheon  10 A or hub portion  11 A onto lever  11 . With further pulling of ligature  20 , distal end loop  20 A will have no choice but to slide off lever  11 . Upward rotation of lever  11  during a suicide attempt may be coupled with circuitry not shown, to trigger an alarm indicating the upward pivoting of lever  11  and/or possible suicide attempt. 
     Switching The Door Latch Mechanism from Classroom (Locked) to Classroom (Unlocked) Modes. 
     Numerous mechanisms are known for allowing levers on interior and exterior sides of a door to selectively engage the latch bolt to open the door or to pivot without engaging the latch bolt, or to be barred from turning. The mechanism illustrated in  FIGS. 11-17  are presented as exemplary of the functions discussed herein of the lever latch lock assembly in combination with the new conical escutcheon lever sub-assembly designed as an improved anti-ligature releasable door lever to defeat ligature type suicide attempts.  FIGS. 11-17  illustrate the above-mentioned keyed switch feature within the A4L latch lock mechanism housing  30  in door  12  applicable in Classroom Mode (Locked). In  FIG. 11  spindle or main door lever shaft  31  is fixedly coupled to exterior side lever  11 . Collar  33  is axially movable on spindle  31  from Position A seen in  FIGS. 11 and 12  corresponding generally to Lever-Dis-engaged Mode where entry from the exterior side is barred, to Position B seen in  FIGS. 13 and 14  representing Lever-Engaged Mode where entry from the exterior side is allowed by pushing down on lever  11 . 
     The switch mechanism is adapted to drive collar  33  between Position A (See  FIG. 12 ) and B (See.  FIG. 14 ) to cause release or driving engagement respectively of latch bolt  35 . As discussed above, in drive engagement of Position B, (to the right as seen in  FIG. 14 ) upward pivot of the lever will drive bolt  35  out of the strike, allowing the door to open. This mechanism may take a variety of cam, gear or other structural forms, with the structure shown in  FIGS. 11-14  being merely one that illustrates simply the principle of operation, as further described below. In these figures door  12  has a conventional mortise latch lock housing and assembly  30  with main spindle or shaft  31 . As seen in  FIGS. 11 ,  12  and  21  spindle  31  has a square cross-section along its length with its ends coupled to exterior side lever  11  and interior side lever  32  respectively. Pivoting of either lever rotates spindle  31 . Slidable on spindle  31  is collar or hub  33  that has right portion  33 R which is round, left portion  33 L which is square, center recess  33 G, and groove  39  to be discussed later. Collar  33  has a square bore  34 A dimensioned to allow collar  33  to slide easily on the square exterior surface of spindle  31  and is keyed to be rotated by any rotation of spindle  31 . Thus, collar  33  can be displaced axially on spindle  31  between (a) a right side Position B toward the exterior side of door  11  seen in  FIGS. 13 ,  14 , and (b) a left side Position A toward the interior side of door  11  seen in  FIGS. 11 ,  12 . 
     Between the left and right side portions of collar  33  is recess  33 G to serve as clearance to separate right and left side portions  33 L and  33 R when switching between positions A and B. In the surface of the right side portion is a shallow groove  39  to be described later. 
     When collar  33  is shifted to the left as seen in  FIGS. 11 and 12 , its right end portion  33 R of round circumference D becomes situated in the square bore  34 N of slightly greater diameter of gear  34  and turns freely therein. Consequently, pivoting of levers  32  or  11  on opposite sides of the door that rotates spindle  31  and collar  33 , does not rotate gear  34  and thus do not drive latch bolt  35  out of engagement with the strike. In this Classroom (Locked) Mode, door  12  cannot be opened from the exterior side which thus bars entry into the room by a patient from the hallway outside this door. 
     When collar  33  is shifted axially to the right side Position B seen in  FIGS. 13 ,  14 , its left portion  33 L of square cross-section becomes situated in square bore  34 N of gear  34 , where the collar&#39;s square outer surface has width W corresponding to but slightly less than square bore  34 N of gear  34 . Thus, pivoting of either lever  11 ,  32  will rotate spindle  31  which will rotate collar  33 , which is drivingly coupled to the rotate gear  34  whose movement drives latch bolt  35  to de-couple from the strike and allow the door to open. The latch bolt  35  in  FIGS. 11-14  is conventional, and the drive mechanism to move the latch bolt in and out of latching engagement with strike may have many various forms. Movement of collar  33  to Position B occurs when a staff person inserts and turns key  36  in lock  37  ( FIGS. 11 and 13 ), which drives collar  33  axially. In this Position B the spindle&#39;s outer square section shape is in drive engagement with hub  34  which drives lock bolt  35  to render door  12  openable by pivoting lever  11  from the exterior side. Axial movement of collar  33  to Classroom (Locked) or (Unlocked) Modes remains until reversed by use of a key in lock  37 . 
     As noted earlier, numerous other lever-engaging mechanisms including cam/follower or spring arrangements or variations of the one shown herein are possible to achieve Position A (lever disengaged) and door locked against entry by a patient, and Position B (lever-engaged) to allow entry from the exterior side, only as allowed by a staff person, and to simultaneously maintain the Anti-Ligature Lock Release capability of the door lock system on both sides. 
     Also shown in  FIGS. 12 and 14  is a toothless section  34 E which does not engage teeth  35 T of bolt  35  when levers  11  or  32  are pulled downward and thus does not drive bolt  35 . 
     The sequence of stages of an attempted hanging suicide are illustrated in  FIGS. 1-10  with the distal end  20 A of ligature  20  initially looped about conical escutcheon  10 A and lever  11 , and the proximal end  20 B formed as a noose which falls to the floor as the suicide attempt is defeated. 
     In  FIG. 5  the distal end  20 A of ligature  20  is shown looped about conical escutcheon  10 A and lever  11 .  FIG. 6  shows that due to pulling on the proximal end  20 B of ligature  20  on the interior side of door  12 , the distal end  20 A has started to pull lever  11  which in turn starts to pivot upward since it has minimal or no resistance to such upward pivoting. In this stage the tied end  20 A has been sliding down the conical walls of the escutcheon  10 A of the shank portion of lever  11 . In  FIG. 7  lever  11  is almost vertical, and the tied end  20 A has almost slid off this handle, and in  FIG. 8  distal end  20 A of ligature  20  is completely free of lever  11 , and consequentially opposite proximal end  20 B has dropped toward the floor on the interior side of door  12 , and the suicide attempt is defeated. 
     In Passage or Classroom (Unlocked) Modes persons on both interior and exterior sides of door  12  can unlatch and open door  12  by pushing downward on the respective interior or exterior side levers, and levers on both sides remain pivotable freely upward to defeat a suicide attempt. 
     The present invention provides a still further mode, herein called privacy mode, where the latch bolt assembly is switched via a key in a lock by a staff person, to bar entry from the exterior side  12 B, while allowing exit from the interior side  12 A, and retaining the upward release condition of levers on both the exterior side and the interior side to defeat a ligature suicide attempt. In “Classroom (Locked) Mode” the lock assembly is altered so that bolt  16  (or an optional drive element coupling the spindle transmission and the bolt  16 ) in a conventional lock assembly not shown, is disengaged from the door lever spindle  31 , which thus bars opening the door from downward pivot of the lever from the exterior side  12 B. At any subsequent time a staff person can, with a key  36  or other simple device such as a coin used in a non-lockable cylinder, switch the bolt&#39;s switch or cam element  38  coupled to collar  33  which is coupled to spindle  31  so that unlatching door  12  from the exterior side  12 B is again possible. 
     In Passage Mode the exterior side lever  11  can be pushed downward where it will overcome normal spring and friction resistance and open the latch bolt  16 , or it can be pivoted upward by ligature  20  where it will pivot freely with minimal resistance. When the lever is pivoted upward the distal part  20 A of any ligature  20  looped about or tied to lever  11 , will slide off quickly because of the conical taper of the escutcheon  10 A and of the lever hub  11 A, which together include smooth continuous or seamless surfaces and no edges that would restrain ligature  20  from sliding off. Thus, in Passage Mode a person on the outside can push lever  11  downward to open door  12  and enter the room; however, lever  11  is freely pivotable upward which will defeat a suicide attempt from a ligature tied to the exterior side lever. Any downward pivoting of a lever by a ligature tied thereto on either side of the door will also release a ligature hanging downward from such lever because of the unique shape of the lever, described in detail below. 
     In the Classroom (Unlocked) Mode the levers on the exterior and interior sides  11 ,  32  are the same as above in Passage Mode; however, in Classroom (Locked) or Lever-Disengaged Mode, on exterior side  12 B, lever  11  is freely pivotable downward where it will not open the door, so that persons cannot enter without admission by a person inside or by a person with a key on the outside. The lever  11  remains freely pivotable upward to not violate the Anti-Ligature safety condition or protocol. One can use a cylinder on either side to set the Mode or an anti-ligature turnpiece apparatus on the interior side to set the Mode. On the interior side the lever will always pivot downward in Lever-Engaged Mode to open the door for egress by the patient or anyone in the room. 
       FIGS. 15-17  illustrate the preferred embodiment of the new lock assembly and door, which has certain differences from the embodiment of  FIGS. 1-14 , but where elements and components similar or the same as those in the embodiment of  FIGS. 1-14  will have the same reference numbers. In both embodiments the objectives are similar, namely to have an ADA-compliant lock system with an anti-ligature design to defeat suicide attempts. The principal difference in the preferred lock system of  FIGS. 15-17  is employment of a two-part spindle where interior side lever  40  is coupled to interior side lever spindle segment  41 , and exterior side lever  42  is coupled to exterior side lever spindle segment  43 . Both spindle segments are square in cross-section, but said spindle segments could have any section whose outer surface can be keyed to a gear or cam that would drive the bolt. In  FIG. 15  spindle segment  41  slides into the mating square bore of sleeve portion  44  of lever  40 . Spring  45  urges spindle  41  inward toward its collar  46  which is pivoted any time that interior side lever  40  is pivoted. 
     The opposite side spindle segment  43  has a similar square shank  47  and an axially spaced reduced diameter part  48 . Collar  49  is formed of left part  49 L secured by screw  49 × to spindle segment  41 , and right part  49 R which is slidable between its left position seen in  FIG. 15  and its right portion seen in  FIG. 16 . The left and right parts  49 L and  49 R are biased inwardly by their respective springs  49 S and  49 T collar part  49 R is axially slidable from the position shown in  FIG. 15  where its portion  49 A overlies and does not engage the reduced diameter portion  48  of spindle segment  43 , to a Position B (see  FIG. 16 ) where said portion  49 A of collar  49  part  49 R slides onto the mating square section  47  of spindle segment  43 . In Position B pivoting lever  42  engaged to collar  49  will drive the lock bolt to open the door  12 . 
     As seen in  FIGS. 15-17  collar segment  49 L is secured to spindle segment  41  by bolt  49 X so that rotation of lever  40  becomes coupled via spindle segment  41  to collar  49  and thence to cam  54  which is fixed at  54 A to collar  49 . 
     Spring  49 T urges outside spindle segment  43 , and spring  49 S urges inside spindle  41  inward to the lock mechanism. Stops are provided to stop each of said spindles from moving too far inward. The stops not shown may be small pins extending perpendicularly through and extending beyond the spindle body at selected axial locations. 
     The mechanism to move collar part  49 R from Position A (lever-disengaged) to Position B (lever-engaged) is a lever  51  driven via lock  52  operated with key  53  by a staff person. Lever  51  drives collar part  49 R between its respective positions. When collar part  49 R is in Position B (lever engaged) and is rotated (as seen in  FIG. 17 ), it will drive cam  54  to allow lock bolt  55  to spring axially out of engagement with the strike plate in the door frame and allow the door to open. 
     Where the latch bolt is normally spring-biased to engage the strike plate, cam  54  drives the latch bolt to disengage from the strike plate. When the cam and collar are disengaged from the spindle segment  43 , rotation of lever  42  will not open the door, this being the Lever-Disengaged Classroom (Unlocked) Mode. In the lock assembly shown collar, part  49 R is moved by the key-lock cylinder  52  and its lever or cam  51 . The inside and outside levers are designed to always defeat suicide attempts by a ligature looped over the door and pulling upward, or by a ligature hanging directly down from the lever. 
     In both embodiments shown above the shape and orientation of the lever and of the coupled escutcheon are significant components alone or in combination with these lock assemblies, in defeating attempts of ligature suicide.  FIGS. 18-20  illustrate a preferred lever  60  and mating escutcheon  61 , where lever  60  extends generally perpendicularly to the central pivot axis X-X of lever  60 &#39;s hub part  62 , and its handle part  60 H of length L is slightly tapered in the direction of its free end, and is slightly inclined, about 1° toward the X-X axis, which enhances the ability of this lever to deflect or direct a ligature to slide off the handle when force is applied to the ligature. Also, the curved near or top end  63  of the lever&#39;s hub part  62  fits essentially seamlessly with the 55° tapered sides  64  of the truncated conical escutcheon  61 , resulting in a smooth continuous curved surface extending from the top end  65  of escutcheon  61  to the generally central top area  63  of lever  60 . 
       FIG. 18  includes the further reference indicia of  61 B and  65  for the base and top surface respectively of the escutcheon, R for the radius of base  61 B, L for the length of handle part  60 H of lever  60  which handle part  60 H extends a radial distance greater than radius R of base  61 B. Also indicated in  FIG. 18 , hub part  62  of lever  60  has a smoothly curved convex top surface  63  that forms a smooth contiguous junction with side walls  64  of the escutcheon  61 , and the handle top part  60 T extends as a smooth contiguous uninterrupted surface with said top surface  63  of said hub part  62 . According to the invention disclosed herein, a ligature looped onto a lever latch assembly will slide off the tapered escutcheon walls and off the smooth contiguous surfaces of the escutcheon, hub and handle parts of the lever. This is further illustrated by  FIGS. 1A ,  4  and  5 - 8 , all showing one end of a ligature slipping off the lever because of the tapers and smooth junctions. 
     The escutcheon  61  shown has generally straight side walls  64  forming a truncated cone at 55° from the horizontal base; however, the truncated escutcheon could have straight walls of a different angle or curved walls as in an egg or hemispherical shape, so long as the walls were sufficiently steep and the lever&#39;s outer surface  63  flows smoothly into the top area  63  of the escutcheon  61  forming a smooth continuous surface off which a ligature will easily slide.  FIG. 19  illustrates a further embodiment of this handle which tapers slightly and inclines about 1° toward the lever&#39;s rotation axis X-X. These aspects further induce any ligature to slide off the handle. 
     The invention herein covers a) the new anti-ligature releasable door lever assembly installable in a door, b) the combination of this assembly with a door, c) the conical escutcheon and lever sub-combination, and d) the method of applying these concepts for anti-ligature releasable door operation. 
     Although the best mode for carrying out the present invention has been described in the foregoing detailed description and illustrated in the accompanying drawings, it will be understood that the invention is not limited to the embodiments enclosed, but is capable of numerous rearrangements, modifications and substitutions of steps and elements without departing from the spirit of the invention. Accordingly, the present invention is intended to encompass such rearrangements, modifications and substitutions of steps and elements as falls within the scope of the appended claims. 
     
       
         
           
               
               
               
             
               
                   
                 APPENDIX A 
               
               
                   
                   
               
               
                   
                 INSIDE (Interior) 
                 Outside (Exterior) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 I. PASSAGE MODE 
                    _Lever freely pivots up 
                    _Lever freely pivots Up 
               
               
                   
                     Lever retracts bolt to 
                     Lever retracts bolt to permit entry 
               
               
                   
                 permit exit 
                 from exterior 
               
               
                 IIA. CLASSROOM 
                    _Lever freely pivots Up 
                    _Lever freely pivots Up 
               
               
                 MODE (LOCKED) 
                     Lever retracts bolt to 
                     Lever decoupled from bolt by use of 
               
               
                   
                 permit exit 
                 a key in a cylinder so that entry from 
               
               
                   
                   
                 exterior is barred 
               
               
                 IIB. CLASSROOM 
                    _Lever freely pivots Up 
                    _Lever freely pivots Up 
               
               
                 MODE (UNLOCKED) 
                     Lever retracts bolt to 
                     Lever retracts bolt to permit entry 
               
               
                   
                 permit exit 
                 from exterior 
               
               
                 III. PRIVACY/STAFF 
                    _Lever freely pivots Ip 
                    _Lever freely pivots Up 
               
               
                 PASSAGE MODE 
                     Lever retracts bolt to 
                     Lever decoupled from bolt, but lock 
               
               
                 (same as Classroom 
                 permit exit 
                 may be unlocked without key which allows 
               
               
                 Mode Locked but 
                   
                 bolt to retract and permit entry from 
               
               
                 Staff person can 
                   
                 exterior 
               
               
                 unlock &amp; enter from 
               
               
                 exterior 
               
               
                   
               
               
                 All up modes could retract latch, but in the above-described embodiments it has been elected to not do so, to reduce friction