Abstract:
An actuator-controlled strike comprising a housing disposable within a doorframe and including a cavity for a spring latch and a dead latch of a mortise-type lockset. A keeper is pivotably mounted within the chamber to engage the spring latch. A pivotably mounted kicker cooperates with the keeper. A pivotably mounted dead latch release is supported by the keeper when the spring latch is within the strike. The keeper is released by the actuator and rotates into a position to ramp the spring latch out of the strike, also allowing the dead latch release to release the dead latch into the cavity, allowing the spring latch to be ramped out of the strike. Pivoting the keeper causes the kicker to urge the spring latch onto an exit ramp on a face of the keeper. The dead latch release can be installed in a plurality of different locations in the housing.

Description:
REFERENCE TO PRIOR APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/179,011, filed Feb. 12, 2014, now U.S. Pat. No. 9,476,227, which is a continuation of U.S. patent application Ser. No. 12/851,848, filed Aug. 6, 2010, now U.S. Pat. No. 8,783,744, which claims the benefit of U.S. Provisional Application No. 61/232,497, filed Aug. 10, 2009. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to strike mechanisms for electrically locking a door in a frame; more particularly, to such strike mechanisms wherein a door latch and dead latch are electrically retained or released by the strike; and most particularly, to an electrically-controlled strike having a pivotable keeper, pivotable kicker, and adjustably positionable pivotable dead latch release platform that all pivot together in synchronized motion to release a door latch from the strike. 
       BACKGROUND OF THE INVENTION 
       [0003]    As is known in the art of door latching, typically an electrically-controlled strike is mounted in a frame portion of a door and engages a mortise-type lockset disposed on or in an edge portion of the door. Typically, the mortise-type lockset includes a spring latch and a dead latch that is linearly spaced-apart from the spring latch along the edge portion of the door. The spring latch is reciprocally moveable between an engaged position so that it can engage the strike, thereby to retain the door in a fastened state, and a release position, wherein the door is released from the fastened state and is free to open. The dead latch is reciprocally moveable between an enabled position (extended) that permits movement of the spring latch from the engaged position to the release position and a disabled position (depressed) that prohibits movement of the spring latch from the engaged position to the release position. The spring latch is resiliently biased into an engaged position and the dead latch is resiliently biased into the enabled position. 
         [0004]    U.S. Pat. No. 6,581,991 B2, the relevant disclosure of which is incorporated herein by reference, discloses an electrically-controlled strike comprising a housing adapted to be mounted in a frame portion of a door and having a cavity with a forwardly disposed opening that is sized and adapted to receive a spring latch and a dead latch when the door is in the fastened state; a spring latch mounted for linear reciprocal movement in a longitudinal throw direction in the housing between an extended position and a retracted position; a dead latch mounted for linear reciprocal movement in the longitudinal throw direction in the housing between an advanced position and a withdrawn position; a head portion supported on the spring latch plunger and being selectively positionable at a selected head location in the opening of the cavity, the head portion being operative to engage spring latch bolt when the door is in the fastened state thereby to accommodate different locations of the spring latch on the edge portion of the door; a striker assembly supported on the dead latch plunger and including an ensemble of strike elements operative to define a strike surface for the dead latch and providing a portal for the spring latch at a selected portal location, the strike elements being selectively arrangeable into different configurations thereby to vary the selected portal location to accommodate different spring latch and dead latch arrangements (as found over a variety of mortise locksets); and a drive operative to reciprocally drive the dead latch from the advanced position to the withdrawn position and to advance the spring latch from the retracted position to the extended position. The invention provides a single electrically actuated door latch structure that can be customized to a variety of spring latch and dead latch arrangements. 
         [0005]    The disclosed mechanism is complex, comprising a large number of components including an electric motor gear train, and worm gear drive; a multiple-component attack head subassembly for enabling and disabling the door spring latch; and a multiple-component strike element subassembly for enabling and disabling the dead latch. The attack head subassembly and the strike element subassembly are driven reciprocally in coordination by the electric motor gear train during operation of the mechanism. 
         [0006]    What is needed in the art is a simplified electrically-controlled strike that can be customized to a variety of spring latch and dead latch arrangements and that has relatively few components operated simply by an electric solenoid. 
         [0007]    What is further needed is a kicker disposed in the strike and cooperative with the keeper and spring latch to facilitate movement of the spring latch toward its released position. 
         [0008]    It is a principal object of the present invention to reduce the cost and complexity of an electrically-controlled strike for a mortise door lockset and to improve spring latch release operation. 
       SUMMARY OF THE INVENTION 
       [0009]    Briefly described, an electrically-controlled strike in accordance with the present invention comprises a rectangular housing disposable within the frame of a door pivotably mounted in the frame. The housing includes an elongate opening defining an entry chamber for a spring latch and a dead latch of a lockset in the door. An entrance ramp for the spring latch and dead latch extends from an edge of the housing. A keeper is pivotably mounted within the chamber to engage and retain the spring latch. A kicker is also pivotably mounted within the chamber and is interlocked with the keeper and engageable by the spring latch. A dead latch release platform is also pivotably mounted within the chamber and is supported at an opposite end by the keeper when the door latch is secured within the strike. When a release command is received, the keeper is released by means of a solenoid and rotates into a position from which the spring latch may be ramped out of the strike opening. The keeper rotation allows the dead latch release platform to pivot into the cavity, releasing the dead latch to be extended into the cavity which allows the spring latch to be ramped into the door. The pivot action of the keeper causes the kicker to engage the nose of the spring latch and urge the spring latch onto an exit ramp formed on a face of the keeper. The spring latch climbs the ramps and exits the strike over the entrance ramp as the door opens in the frame. The dead latch release platform can be installed in any of a plurality of different vertical locations in the housing opening to accommodate any of a plurality of different lockset arrangements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The present invention will now be described, by way of example, with reference to the accompanying drawings, in which: 
           [0011]      FIG. 1  is a side elevational view of a door in a secure condition at a first door position within a door frame and having a portion of the door frame broken away to show an electrically-controlled strike in accordance with the present invention and operable with a mortise-type dead latch assembly of the door; 
           [0012]      FIG. 2  is an isometric view of a prior art mortise lockset for use with an electrically-controlled strike in accordance with the present invention; 
           [0013]      FIG. 3  is a perspective view of a strike plate according to the prior art for use with a mortise-type dead latch assembly such as that shown in  FIG. 2  which would be replaced by an electrically-controlled strike in accordance with the present invention; 
           [0014]      FIG. 4A  is an exploded perspective view of a complete electrically-controlled strike in accordance with the present invention; 
           [0015]      FIG. 4B  is a perspective view of an electrically-controlled strike in accordance with the present invention; 
           [0016]      FIG. 5  is a cross-sectional view showing a door having a mortise lockset latched in a frame having an electrically-controlled strike in accordance with the present invention, the strike being in secured mode; 
           [0017]      FIG. 6  is a cross-sectional view sequential to the view shown in  FIG. 5 , showing the strike in an early stage of unlocking the spring latch and dead latch of the mortise lockset; 
           [0018]      FIG. 7  is a cross-sectional view sequential to the view shown in  FIG. 6 , showing the strike in a later stage of unlocking the spring latch and dead latch of the mortise lockset; 
           [0019]      FIG. 8  is a cross-sectional view sequential to the view shown in  FIG. 7 , showing the strike in a late stage of unlocking the spring latch and dead latch of the mortise lockset; 
           [0020]      FIG. 9A  is a perspective view of a first embodiment of dead latch release subassembly for use in an electrically-controlled strike in accordance with the present invention; 
           [0021]      FIG. 9B  is a perspective view of a second embodiment of dead latch release subassembly for use in an electrically-controlled strike in accordance with the present invention; 
           [0022]      FIG. 10  is a plan view showing five different configurations for installation of the dead latch release subassembly, corresponding to five different mortise lockset arrangements of dead latch and spring latch; 
           [0023]      FIG. 11A  is a perspective view of a solenoid actuation mechanism in accordance with the present invention, showing the strike in locked mode; and 
           [0024]      FIG. 11B  is a perspective view of a solenoid actuation mechanism in accordance with the present invention, showing the strike in unlocked mode. 
       
    
    
       [0025]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrates currently preferred embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    The present invention is broadly directed to an automated door latch release system that is adapted to be installed in a door jam or frame so that it can operate with a mortise-type lock with dead latch assembly such as those found in typical commercial and industrial applications. The present invention also encompasses a method for automated door release. The present invention is particularly adapted for use with security doors in industrial and commercial applications wherein the security system can be electronically activated to release the door so that it may be moved from a secured first door position wherein it is secured within the door jam to an open position. The automated door lock release, also referred to herein as an “electrically-controlled strike,” is primarily adapted for use with a mortise-type dead latch assembly mounted in the door. Here, the mortise-type dead latch assembly includes a spring latch and a dead latch that are spaced-apart from one another along the edge of the door. Moreover, the present invention is specifically adapted to be mounted in the dimensions of a typical door jam, requiring no further modifications, other than the location of the dead latch platform, to interface with a variety of different styles of mortise-type dead locks. 
         [0027]    An automated door lock release or strike in accordance with the present invention is an improvement over the prior art automated door latch release disclosed in U.S. Pat. No. 6,581,991 B2 and is intended to function as a direct replacement thereof. 
         [0028]    Referring to  FIG. 1 , an embodiment of the invention disclosed in U.S. Pat. No. 6,581,991 B2 is in the form of a prior art automated door latch actuator  10  that is received in a cavity  12  in a typical door jam  14 . Actuator  10  includes an outer housing  16  which mounts its electrical and mechanical components. The electrical components in turn are electrically in communication by means of wiring  20 . Actuator  10 , for example, may be electrically in communication with a source  17  of electrical power such as for example, a 12 or 24 volt circuit, and with a trigger device  22 . Activation of the trigger device will cause the door latch actuator to activate. The trigger device  22  may typically be a switch whose contacts selectively actuate the door latch actuator. The trigger device  22 , however, is often incorporated into a control entry device such as a card reader or digital entry keypad. Here, an authorized card is presented or an authorized code is entered into trigger device  22 . 
         [0029]    A typical door  24  is shown in  FIG. 1  in a first or closed position. Again, for example purposes, door  24  may be pivotally mounted so that it can move between a closed position and an open position. 
         [0030]    Door latch actuator  10  is constructed to interface with a mortise-type lockset assembly  30  according to the prior art, exemplarily shown in  FIG. 2 . A prior art mortise-type lockset assembly  30  includes a spring latch  32  and a dead latch  34 . Spring latch  32  and dead latch  34 , when mounted in a door, are linearly spaced-apart from one another along the edge portion of the door. Both spring latch  32  and dead latch  34  are spring-biased to extend outwardly from lockset assembly  30 . Thus, as one of ordinary skill in the art can appreciate, spring latch  32  is slideably moveable between an advanced or “engaged position”, wherein the spring latch  32  is fully extended from the edge portion of the door such that it can engage the latch bolt receiving cavity  46  ( FIG. 3 ), and a retracted or “release position” wherein spring latch  32  is retracted into the door and becomes disengaged from the latch bolt receiving cavity  46 , allowing the door to open. 
         [0031]    Dead latch  34  similarly is reciprocally moveable between an extended or “enabling position” and a depressed or “disabling position”. As is known in the prior art, when the dead latch is held in its disabling position, it prevents (“disables”) movement of the spring latch bolt from moving from the engaged position to the release position. However, when the dead latch extends into the enabling position, the spring latch bolt may reciprocate between the engaged position and the release position. In  FIG. 2 , dead latch  34  is shown in the extended or enabling position and spring latch  32  is shown in the engaged position. Spring latch  32  is free to be urged into lockset assembly  30  in response to an opening force on door  24  as by a user rotating the door handle  29 . 
         [0032]    With reference now to  FIG. 3 , a prior art strike plate  36  for use with mortise-type locksets of the prior art, such as lockset assembly  30 , includes a rectangular central body portion  38  having oppositely projecting mounting tabs  40  provided with holes  42  adapted to receive screws for mounting on door jam  14 . A lateral flange  44  projects away from central body portion  38  in a slightly curved configuration so as to interact with the curved edges of spring latch  32  and dead latch  34  when the door swings shut. A latch bolt receiving cavity  46 , in the form of an opening, is provided in central body  38  of strike plate  36  so that, when the door closes, spring latch  32  extends into receiving cavity  46  to hold the door in the closed position. Dead latch  34 , on the other hand, bears against the surface of strike plate  36  in the region designated  48  and is held in the depressed or disabling position thereby to lock the door. However, and with reference to  FIG. 2 , mortise-type lockset assembly  30  typically includes a key lock  35  that includes a mechanism to selectively retain spring latch  32  in the engaged position or to release spring latch  32  so that it may move between the engaged position and the release position. This construction is believed to be well-known to those skilled in the art and is not part of the present invention. 
         [0033]    Referring now to  FIGS. 4A through 11 , an improved electrically-controlled strike  110  in accordance with the present invention comprises a housing  116  including a rectangular central body portion  138  having oppositely projecting mounting tabs  140  provided with holes  142  for receiving screws  143 . As best seen in  FIG. 4A , housing  116  includes a longitudinal length (LL), a width (W), and a depth (D). An improved strike plate  136  having a central cutout portion  150  is adapted to fit over housing  116  to secure housing  116  via screws  143  into a cavity in a door jamb  14  as described above for prior art door latch actuator  10  ( FIG. 1 ). Housing  116  is provided along an edge with a lateral flange  144  preferably running substantially the full longitudinal length LL of housing  116  that serves as an entry and exit ramp for a spring latch and dead latch as described below. 
         [0034]    A dead latch release subassembly  152  (best shown in  FIG. 9A ) comprises a dead latch release platform  154  pivotably disposed in a platform mount  156 . A compression spring  158  is disposed between platform  154  and mount  156  to resiliently urge subassembly  152  into the configuration shown in  FIGS. 5 and 8 . Platform mount  156  is provided with a pair of hooks  160  and a gib  162 . Hooks  160  engage notches  163  ( FIG. 4A ) in a wall of housing  116  and gib  162  engages a supportive bench  161  ( FIG. 5 ). 
         [0035]    A first embodiment of the dead latch release subassembly  152  ( FIG. 9A ) includes a nose tang  164 . A second embodiment of the dead latch release subassembly  152 ′ ( FIG. 9B ) includes a roller  164 ′ disposed in a fork  165 , replacing tang  164 . 
         [0036]    A keeper  166  is pivotably mounted longitudinally of housing  116  and in the locked position ( FIG. 5 ) engages nose tang  164  (or roller  164 ′, not shown in  FIG. 5 ) to support dead latch release platform  154  or  154 ′. Thus, when door lockset assembly  30  ( FIG. 2 ) is in the locked mode, dead latch  34  is held in a depressed position in assembly  30  by release platform  154 . Surface  169  of keeper  166  further engages lockset spring latch  32  along surface  168  and door opening force  178  is directed substantially perpendicular to surface  169 , thus preventing door  24  from being opened. A return spring  167  disposed between keeper  166  and housing  116  urges keeper  166  toward the locked position shown in  FIG. 5 . 
         [0037]    A kicker  170  is also pivotably mounted longitudinally of housing  116  and rests against a leg  172  of keeper  166 . A return spring  173  is mounted on kicker  170  and constrained by body  116 . Return spring  173  may be but is not limited to, a leaf, compression or torsion spring. As described in detail below, a solenoid is linearly operative against keeper  166  to selectively permit rotation of the keeper as described below when an unlocked mode for mechanism  110  is desired. 
         [0038]    Referring to  FIGS. 6 through 8 , in operation of strike  110  the unlocking sequence is shown. 
         [0039]    In  FIG. 6 , as keeper  166  begins to rotate counterclockwise in response to opening force  178  on door  24 , nose tang  164  or roller  164 ′ is no longer supported by keeper  166 . Because spring  158  in subassembly  152  is deliberately provided to be weaker than the dead latch spring in mortise lockset  30 , dead latch release platform  154  is caused by dead latch  34  to pivot in platform mount  156 , allowing the dead latch to extend from door  24  into its extended, enabling position. Spring latch  32  is now free to be urged into lockset  30 . 
         [0040]    In  FIG. 7 , as keeper  166  continues to rotate counterclockwise, leg  172  urges kicker  170  to rotate correspondingly in a clockwise direction. Kicker  170  is so named because it literally kicks spring latch  32  out of locked engagement with keeper  166 . When the nose  174  of spring latch  32  reaches the inclined surface  176  of keeper  166  ( FIG. 7 ) by the action of kicker  170 , opening force  178  on door  24  serves to cause nose  174  to slide along inclined surface  176  as spring latch  32  is further forced into lockset  30  until nose  174  reaches lateral flange  144  ( FIG. 8 ) and door  24  is freed from engagement with strike  110 . 
         [0041]    Referring to  FIG. 10 , dead latch release subassembly  152  may be positioned in notch  163  ( FIG. 4A ) at any one of a plurality of positions, allowing strike  110  to be used with any of a plurality of mortise locksets having differing position arrangements of their dead latches and spring latches. In the example shown herein, strike  110  may accommodate five positions  110 A through  110 E of subassembly  152  corresponding to five sets of notches  163  in housing  116  ( FIG. 4A ). Moreover, because of the flexibility of strike  110  to accommodate various positions of the dead latch relative to the spring latch, strike  110  in accordance with the invention may be used, of equal utility, in either a right-hand-hinge or left-hand-hinge door frame. 
         [0042]    Referring to  FIG. 11A , actuator  180 , in the form of a linear-acting solenoid, is disposed in a cavity  181  in housing  116  and includes a plunger formed as an inhibitor  182 . A compression spring  184  disposed between actuator  180  and inhibitor  182  urges inhibitor  182  into an interfering relationship with mating teeth  186  on keeper  166  to prevent rotation of keeper  166 , thereby locking spring latch  32  into strike  110  ( FIG. 5 ) when actuator  180  is de-energized. Referring to  FIG. 11B , when actuator  180  is energized, inhibitor  182  is moved in direction  188  into a non-interfering relationship with mating teeth  186  to permit rotation of keeper  166  to release spring latch  32  from strike  110 . Thus, the strike is in a “fail secure” mode meaning that, when solenoid  180  is not energized, the door is prevented from disengaging strike  110 . 
         [0043]    It should be noted that, by re-aligning inhibitor  182  relative to mating teeth  186  on keeper  166  as shown in  FIG. 11B , when actuator  180  is not energized, inhibitor  182  can be moved into an interfering relationship when actuator  180  is energized. By re-aligning inhibitor  182  in this manner, the strike can be transformed to operate in a “fail safe” mode (that is, when the solenoid is not energized, the door is permitted to disengage the strike). 
         [0044]    While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims.