Abstract:
A lock assembly for use with a sliding door. The lock assembly includes a non-handed miniature mortise lock having a retractable and extendable tongue able to move between a locked position and an unlocked position. The assembly includes a rotatable spindle and a slidable piece. Manipulation of the slidable piece rotates the rotatable spindle and activates the mortise lock between the locked and unlocked positions.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims priority of U.S. Provisional Application No. 60/692,541, filed Jun. 21, 2005, under Title 35, United States Code, Section 119(e). 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to locks and locking assemblies. More particularly, the present invention relates to an improved locking assembly suitable for the locking of a sliding door. 
   2. Description of the Prior Art 
   Locks generally used in conjunction with a sliding door typically include a locking element having a beak or tongue which hooks into an opening on a corresponding latch, strike or keeper. Such types of locks can be fairly easy to overcome and often times provide little resistance to unauthorized entry through the sliding door or unauthorized unlocking of the lock itself. 
   Another problem often associated with locks for sliding doors is the tongue may be in an extended, or locked, position while the door itself is open or ajar. The door may be inadvertently closed while the tongue is extended, thereby causing damage to any one or more of the door, the tongue, the lock as a whole or the adjacent keeper. This can result in the undesirable and potentially expensive repair, or even replacement, of any one or more of the aforementioned components. 
   Referring first to  FIGS. 1 and 2 , an example of a prior art locking assembly used in conjunction with sliding doors is shown and described.  FIGS. 1 and 2  show an interior escutcheon or latch  11  in a prior art locking assembly  10  for use with a sliding door (not shown). The interior escutcheon  11  includes a movable locking element  12 . The locking element  12  is shown in greater detail in  FIG. 2 . 
   Locking element  12  includes a locking portion  13  and is movable in an upwardly and downwardly direction for the locking and unlocking of locking assembly  10  in response to movement of a control switch  14 . Upon activation in a downwardly direction, locking element  12  secures onto an opening in an adjacent keeper (not shown) to secure the locking assembly and to lock the door. This prior art locking assembly also includes a backup lock  16  for providing additional support to the locking elements as needed or desired, such as at night, or if the house, building, etc. will be vacant for an extended period of time. However, as noted above, one problem with such prior art locking assemblies is that the locking elements can be fairly easily disengaged from the keeper to unlock the door in an unauthorized manner, or can be forced open in a relatively simple manner, even if the backup is activated. 
   Therefore, there is a need for an improved locking assembly suitable for use with a sliding door and that can easily and inexpensively replace the prior art locking assembly already in place with the sliding door to be locked. 
   SUMMARY OF THE INVENTION 
   According to one broad aspect of the present invention, there is provided a locking assembly incorporating the use of a modified miniature mortise lock for use with a sliding door. 
   It is an object of the present invention to provide an improved locking assembly incorporating the use of a modified miniature mortise lock for use on a sliding door. 
   Another object of the present invention is to provide an improved locking assembly having a modified miniature mortise lock that is adjustable. 
   Yet another object of the present invention is to provide an improved locking assembly having a modified miniature mortise lock that does not require cams having different lengths. 
   Still yet another object of the present invention is to provide an improved locking assembly having a retractable tongue for preventing damage to the mortise lock and/or to the adjacent door stile due to improper closing of a sliding door. 
   It is an additional object of the present invention to provide an improved locking assembly that is stronger and more durable than conventional locking assemblies for use with sliding doors. 
   It is yet another object of the present invention to provide a locking assembly that provides greater resistance to unauthorized unlocking of the locking assembly for use with a sliding door. 
   A further object of the present invention is to provide an improved locking assembly that easily replaces a conventional locking assembly that is in use with a sliding door. 
   Another object of the present invention is to provide an improved locking assembly that inexpensively replaces a conventional locking assembly that is in use with a sliding door. 
   Yet another object of the present invention is to provide an improved locking assembly employing the use of a six-sided spindle for activating the modified miniature mortise lock. 
   Still yet another embodiment of the present invention is to provide an improved locking assembly employing the use of a non-handed modified miniature mortise lock. 
   Other objects will become apparent from the description to follow and from the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a prior art lock assembly. 
       FIG. 2  is a perspective view of the locking element of the prior art lock assembly as shown in  FIG. 1 . 
       FIG. 3  is an exploded view of the lock assembly according to the present invention. 
       FIG. 4A  is a perspective view of the mortise lock of the lock assembly as shown in  FIG. 3 . 
       FIG. 4B  is a side view of the mortise lock as shown in  FIG. 4A ; 
       FIG. 5  is a perspective view of the keeper portion of the lock assembly as shown in  FIG. 3 . 
       FIG. 5A  is a cross-sectional view of the keeper portion of the lock assembly as shown in  FIG. 5 . 
       FIG. 6  is a perspective view of the keeper&#39;s bracket of the lock assembly as shown in  FIG. 3 . 
       FIG. 6A  is a cross-sectional view of the keeper&#39;s bracket of the lock assembly as shown in  FIG. 6 . 
       FIG. 7A  is a perspective view of one embodiment of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 7B  is a perspective view of a second embodiment of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 8  is a perspective view of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 9A  is a perspective and partially exploded view of the fitting between the exterior escutcheon of the lock assembly of the present invention as shown in  FIG. 3  and a door stile. 
       FIG. 9B  is a perspective view of the fitting between the interior escutcheon of the lock assembly of the present invention as shown in  FIG. 3  and a door stile. 
       FIG. 10A  is a front, interior view showing the operation of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 10B  is a perspective, interior view showing the operation of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 11A  is a front, exterior view showing the operation of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 11B  is a perspective, exterior view showing the operation of the lock assembly of the present invention as shown in  FIG. 3 . 
       FIG. 12  is a perspective view of a spindle device for use with the lock assembly of the present invention as shown in  FIG. 3 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The fundamental components of a lock assembly  100  for a sliding door are shown in  FIG. 3 . Lock assembly  100  includes an interior escutcheon or latch  102 , an exterior escutcheon or latch  104  and a mortise lock  106 . It should be appreciated that relative to a door stile (not shown in  FIG. 3 ) onto which assembly  100  is secured, i.e., a door stile for a sliding door leading into a house, interior escutcheon  102  is the portion of assembly  100  facing into the house and exterior escutcheon  104  is the portion of assembly  100  facing the external environment or outside the house. It should also be appreciated that assembly  100 , and the components thereof as explained below, generally comprises any material conventional in the art, such as brass or steel. 
   Interior escutcheon  102  further includes an interior facing  114 , an exterior protective facing  116  and a slidable device, such as a slider piece  122 , fitted between interior escutcheon  102  and exterior escutcheon  104 . Slider piece  122  is vertically slidable or movable when assembly  100  is in operation. Exterior escutcheon  104  further includes an interior facing  118  facing towards interior escutcheon interior facing  114  and an exterior protective facing  120 . Exterior escutcheon exterior facing  120  may be comprised of any strong, sturdy material resistant to tampering, breaking or any other form of unauthorized access common in the art, such as steel or brass. Assembly  100  further comprises a wafer or key cylinder  108 , a keeper  110  and a keeper&#39;s bracket  112 . Exterior escutcheon  104  further comprises a key cylinder receiving hole  182  having an annular sidewall  182   a  for receiving key cylinder  108  in a secure engagement. 
   Referring now to  FIGS. 4A and 4B , mortise lock  106  is shown and described in greater detail. It should be appreciated that mortise lock  106  is not a standard-sized mortise lock common in the art, but is a miniature modified mortise lock having a size compatible with assembly  100  for use on a sliding door (not shown). It should also be appreciated that mortise lock  106  will be discussed having a vertical arrangement relative to assembly  100 ; however, mortise lock  106  is not limited to this arrangement. 
   Mortise lock  106  comprises a substantially-rectangular shaped housing  107  comprising a top end  134 , when mortise lock  106  is vertically arranged, a bottom end  136 , two opposing narrow sides  132   a ,  132   b  extending from top end  134  to bottom end  136  and two opposing wide sides  130   a ,  130   b  extending from top end  134  to bottom end  136 . Wide sides  130   a ,  130   b  and narrow sides  132   a ,  132   b  are secured to each other at perpendicular angles to form substantially rectangular-shaped mortise lock housing  107 . Mortise lock  106  also includes a moveable locking element or tongue  142  that is moveable between a locked position (extended) and an unlocked position (retracted). 
   Still referring to  FIG. 4A , opposing narrow sides  132   a ,  132   b  will be referred to individually as a front side  132   a  and a rear side  132   b . Front side  132   a  includes an accessible opening  184  for providing tongue  142  with pivotable access into and out of housing  107  and between the locked position (i.e., extended and substantially outside mortise lock  106 ) and the unlocked position (i.e., retracted and substantially extending inside housing  107 ). Mortise lock  106  further includes two opposing flanges  138   a ,  138   b  extending upwardly from top end  134  and downwardly from bottom end  136 . In other words, when mortise lock  106  is in a vertical arrangement relative to assembly  100 , flange  138   a  extends in an upwardly direction from top end  134  and flange  138   b  extends in a downwardly direction from bottom end  136 . Flanges  138   a ,  138   b  have substantially the same width as opposing sides  130 . Opposing flanges  138   a ,  138   b  are both comprised of a rectangular body  139  defining a rectangular securing hole  140 . It should be appreciated that the rectangular shape of flanges  138  and securing hole  140  is but one appropriate configuration of flanges  138  and respective hole  140 , and flanges  138  and respective hole  140  may include any shape applicable in the art. It should also be appreciated that opposing flanges  138  may be secured to mortise lock housing  107  by any manner known in the art, such as by rivets, welding, machining, or the like, or can be integrally formed with housing  107  from a single piece of material as housing  107 . 
   Still referring to  FIGS. 4A and 4B , a six-sided drive shaft  160  extends through housing  107 . It should be appreciated that drive shaft  160  need not be limited to being six-sided, but may have any configuration for engaging with a corresponding spindle (discussed below). Drive shaft  160  is in mechanical communication with locking element  142  via a drive assembly (not shown) for causing the extension and retraction of locking element  142  relative to housing  107 . An accessible opening  160   a  is provided on each side of housing  107  for providing access to drive shaft  160 . The operation of drive shaft  160  is discussed in further detail below. The drive assembly itself is a typical drive assembly known in the art, and therefore a detailed discussion thereof is omitted for the sake of brevity. 
   As seen in  FIGS. 4A and 4B , locking element  142  includes a securable locking portion or tongue  142   a . Tongue  142   a  is lockably securable to a keeper assembly  113  (discussed below) when locking element  142  is activated and extended. 
   Turning now to  FIGS. 5 ,  5 A,  6  and  6 A, keeper  110  ( FIG. 5 ) and keeper&#39;s bracket  112  ( FIG. 6 ) are secured together to form a keeper assembly  113  ( FIG. 3 ) and are shown and described. Keeper assembly  113  is secured to the interior of a door frame (not shown) opposite from the door stile in which assembly  100  is secured. Keeper  110  includes a substantially rectangular base portion  145  having two opposing ends  146 . Each end of opposing ends  146  defines a screw hole  147  for providing access to a screw  149  through keeper  110  for securing keeper assembly  113  ( FIG. 3 ) to the door frame. Keeper  110  further includes a central portion  148  comprised of four angled walls  186  extending outwardly from base portion  145  and converging at an end wall  188  to form a cavity  190  ( FIG. 5A ). During operation of assembly  100 , cavity  190  receives tongue  142   a  in a secure hooking engagement, thereby locking assembly  100  in place and preventing the sliding door from being opened. 
   As shown in  FIGS. 6 and 6A , keeper&#39;s bracket  112  includes an upper portion  150 , a lower portion  152  and a central portion  156  having two angled sidewalls  192 , converging at an end wall  194  to form a central portion  195  defining a keeper bracket cavity  196  ( FIG. 6A ) and which corresponds to cavity  190 . As seen in  FIG. 6 , one sidewall extends from the bottom end of upper portion  150  and the other sidewall extends from the top end of lower portion  152 . A screw hole  154  is provided in each of upper portion  150  and lower portion  152 . It should be appreciated that keeper cavity  190  and keeper&#39;s bracket cavity  196  have substantially the same shape whereby keeper  110  and keeper&#39;s bracket  112  are engageable such that central cavity  195  securely fits into cavity  190  and such that screw holes  154  of keeper&#39;s bracket  112  correspond to and align with screw holes  147  of keeper  110 . Typically, keeper&#39;s bracket  112  is machined from a single piece of material to form the configuration set forth above. 
   During operation, keeper&#39;s bracket  112  and keeper  110  are arranged together in the manner set forth above, and are secured to a corresponding cut-out portion of the door frame (not shown). This arrangement provides keeper assembly  113  with added strength for facilitating locking of assembly  100  and for preventing unauthorized access. 
   Referring now to  FIGS. 7A ,  7 B and  8 , the securing arrangement of mortise lock  106  onto interior escutcheon  102  is shown and described. It should be appreciated that mortise lock  106  is a non-handed mortise lock. In other words, mortise lock  106  is employable in the form of either of two embodiments, one embodiment being with a left-handed latch ( FIG. 7A ) and the second embodiment being with a right-handed latch ( FIG. 7B ). 
   Referring first to  FIG. 7A , mortise lock  106  is shown and described as secured to a right-handed interior escutcheon (latch)  102 . It should be appreciated that the components of interior escutcheon  102  are substantially identical whether interior escutcheon  102  is right-handed or left-handed. Interior escutcheon  102  comprises vertical slider piece  122  movably affixed to interior escutcheon  102  at interior facing  114  and two opposing stationary securing posts  128 . Securing posts  128  both include a base portion  128   a  having a width and an upper portion  128   b  having a width smaller than that of base portion  128   a  to form a support seat  128   c  for supporting mortise lock  106 . During operation, mortise lock  106  is secured to securing posts  128  by inserting securing posts  128  through holes  140 . In turn, flanges  138  rest on seats  128   c.    
   Vertical slide  122  further includes two opposing guide spaces  129  which fit over securing posts  128  and allow securing posts  128  to extend through vertical slide  122 . Interior escutcheon  102  also includes a six-sided rotational and movable actuator, or spindle  158  ( FIGS. 7A ,  7 B and  12 ) extending outwardly from interior escutcheon interior facing  114 . Spindle  158  is in mechanical communication with mortise lock  106  and is movable in a horizontal direction along the width of interior escutcheon  102 , as indicated by directional arrow “A” and between a left-handed position ( FIG. 7A ) and a right-handed position ( FIG. 7B ). In each position, spindle  158  may be lockably secured in place by a locking mechanism (not shown), such as a snap-lock, to prevent inadvertent or unnecessary horizontal movement of spindle  158 . Interior escutcheon  102  further includes a spindle track  170  having a first vertical portion  172 , a second vertical portion  174  and a horizontal portion  176 . Horizontal portion  176  of track  170  defines the horizontal movement of spindle  158  on interior escutcheon  102  between the left-handed position and the right-handed position along direction A. Vertical portions  172 ,  174  allow for movement of slider piece  11  relative to spindle  158 . In other words, vertical portions  172 ,  174  allow slider piece  122  to move vertically along interior escutcheon  102  without being obstructed by spindle  158 . Vertical portions  172 ,  174  also engage spindle  158 , such as in a manner corresponding to the six-sided arrangement of spindle  158 . The movement of slider piece  122  moves either vertical portion  172 ,  174  (depending on whether a right-handed or left-handed latch is being used) relative to spindle  158  to rotate spindle  158  in a clockwise or counter-clockwise direction accordingly. 
   As mentioned above, a six-sided drive shaft  160  ( FIG. 8 ) is provided through housing  107  and includes accessible opening  160   a  on each side of mortise lock  106  (as explained earlier). Accessible opening  160   a  ( FIGS. 7A ,  7 B,  8 ) provides an access point for spindle  158  into mortise lock  106  to facilitate the mechanical communication between spindle  158  and mortise lock  106  and for operation of mortise lock  106 , as explained in further detail below. 
   Mortise lock  106  is securable onto interior escutcheon  102  by placing mortise lock  106  onto interior escutcheon interior facing  114  such that holes  140  of opposing flanges  138  of mortise lock  106  are aligned with opposing securing posts  128  ( FIG. 8 ), as explained above. It should be appreciated that opposing securing posts  128  are distanced from each other at a distance that is the same as the distance between opposing holes  140  and that securing posts  128  and holes  140  have corresponding rectangular shapes to facilitate the engagement between securing posts  128  and holes  140 ; however, securing posts  128  and holes  140  can have alternative corresponding shapes. When mortise lock  106  is secured onto interior escutcheon  102 , securing posts  128  receive opposing flanges  138  by the engagement between holes  140  and securing posts  128 . In turn, drive shaft  160  of mortise lock  106  is aligned with and receives spindle  158  in a six-sided engagement, the six-sided shape of drive shaft  160  corresponding to the six-sided shape of spindle  158 . During operation of assembly  100  (i.e., upwardly or downwardly vertical movement of slider piece  122 ), spindle  158  contacts drive shaft  160  which is operatively connected to locking element  142  via a drive assembly (not shown) which affects movement of locking element  142 . Mortise lock  106  is thereby secured onto interior escutcheon  102  in a flush manner. 
   For application of mortise lock  106  onto a right-handed interior escutcheon  102  ( FIG. 7B ), spindle  158  is manually moved from the left-handed position on interior escutcheon  102  ( FIG. 7A ) to the right-handed position on interior escutcheon  102  ( FIG. 7B ) along horizontal portion  176  of track  170 . Mortise lock  106  is subsequently flipped-over such that spindle  158  and drive shaft  160  remain aligned. Mortise lock  106  is secured onto interior escutcheon  102  in the manner described above. 
   Turning now to  FIGS. 9A and 9B , the placement of assembly  100  relative to a door stile  164  is shown and described. Door stile  164  includes an exterior cut-out portion  166  ( FIG. 9A ) and an interior cut-out portion  167  ( FIG. 9B ) for receiving assembly  100 . Specifically, cut-out portions  166  and  167  include an edge  166   a  and  167   a , respectively, around the periphery of cut-out portions  166  and  167 . Exterior escutcheon  104  includes an edge  104   a  around the periphery of exterior escutcheon  104  and an edge  102   a  surrounds the periphery of interior escutcheon  102 . Exterior escutcheon  104  is secured onto door stile  164  by placing exterior escutcheon  104  into cut-out portion  166  such that edge  104   a  corresponds to and abuts against edge  166   a  in a flush arrangement and interior escutcheon  102  is secured onto door stile  164  by placing interior escutcheon  102  into cut-out portion  167  such that edge  102   a  corresponds to and abuts against edge  167   a  in a flush arrangement. In turn, exterior escutcheon  104  is secured to interior escutcheon  102  inside door stile  164  to secure assembly  100  to door stile  164  by two pairs of corresponding cylinders  124  and  126  on interior escutcheon  102  and exterior escutcheon  104 , respectively ( FIGS. 3 ,  10 B and  11 B). Door stile  164  further includes an access space  168  for providing access to locking element  142  for movement, thereby facilitating the securing of locking element  142  to keeper assembly  113 . When assembly  100  is in place and locked in place with keeper assembly  113 , locking element  142  extends outwardly from mortise lock  106  through access space  168 . 
   Referring now to  FIGS. 10A and 10B , the operation of mortise lock  106  from the inside is shown and described. As shown in  FIG. 10B , slider piece  122  further includes an accessible knob  162  for affecting movement of slider piece  122 . Exterior facing  116  of interior escutcheon  102  includes an access opening  198  for providing a user with access to accessible knob  162 . Access opening  198  is substantially oval-shaped; however, it should be appreciated that access opening  198  may have any shape conventional in the art. Accessible knob  162  is directly secured to slider piece  122  and the manual movement of knob  162  in either an upward or downward direction causes the movement of slider piece  122  in the same upwardly or downwardly direction. Upwardly or downwardly movement of slider piece  122  in turn causes the locking or unlocking of mortise lock  106 , as explained below. 
   In order to operate mortise lock  106  from the inside, the user manipulates knob  162  either upwardly or downwardly, as shown in  FIG. 10B . In this instance, mortise lock  106  is shown in a locked position with locking element  142  activated and extended. By pushing knob  162  downwardly, the movement of slider piece  122  is affected in the same direction and locking element  142  retracts back into mortise lock  106 , thereby unlocking assembly  100 . As shown in  FIG. 10A , drive shaft  160  is in contact around spindle  158  and is in mechanical communication with locking element  142 . Upon movement of slider piece  122  by a user who is manually moving accessible knob  162 , slider piece  122  moves upwardly or downwardly depending on whether assembly  100  is being locked or unlocked. In the case of moving slider piece  122  downwardly, as shown in  FIGS. 10A and 10B , spindle  158  rotates counterclockwise as shown by the curved arrow in response to the movement of vertical portion  174  against spindle  158 , spindle  158  being biased in position to prevent unwanted horizontal movement along directional line A. The rotational movement of spindle  158  causes the rotation of drive shaft  160  via the drive assembly (not shown), thereby causing locking element  142  to retract into mortise lock  106 , in turn unlocking assembly  100 . Alternatively, the upward movement of accessible knob  162  by the user causes the upward movement of slider piece  122  and causes the rotational movement of spindle  158  in an opposite direction or counter-rotational direction. This rotates drive shaft  160  in an opposite direction and extends locking element  142  out of mortise lock  106 , thereby locking assembly  100 . 
   Referring now to  FIGS. 11A and 11B , the operation of mortise lock  106  from the outside is shown and described. As shown in  FIG. 11B , slider piece  122  is in mechanical communication with key cylinder  108  which is accessible through exterior facing  120  of exterior escutcheon  104 . Key cylinder  108  includes a cylinder pin  178  operatively connected to slider piece  122 . The locking and unlocking of mortise lock  106  from the outside is caused by a user turning key cylinder  108  by way of a corresponding key  180 . Turning key  180  in a locking direction causes slider piece  122  to move in a locking direction (i.e., upwardly), thereby causing spindle  158  to rotate counterclockwise in response to the movement of vertical portion  174  against spindle  158 . The rotation of spindle  158  rotates drive shaft  160  and effectively causes locking element  142  to rotate clockwise to extend from mortise lock  106  and lock assembly  100 . The turning of key  180  in key cylinder  108  in the opposite direction, i.e., in an unlocking direction, causes slider piece  122  to move in an unlocking direction (i.e., downwardly). The movement of vertical portion  174  against spindle  158  rotates spindle  158  in a counter-rotational direction. The counter-rotational movement of spindle  158  rotates drive shaft in a counter-rotational direction causing locking element  142  to retract back into mortise lock  106  and unlock assembly  100 . 
   An additional advantage of mortise lock  106  is locking element  142  being a retractable locking element  142  when locking element  142  is in an extended or locked position, but the door is ajar or open and not securely closed. In this instance, a user may close the door forcing locking element  142  to undesirably jam against the adjacent keeper assembly  113 . Locking element  142 , upon contact with keeper assembly  113 , retracts by pivoting back into accessible opening  184  of mortise lock  106  instead of remaining in the extended position. The automatic retraction of locking element  142  into mortise lock  106  prevents damage to mortise lock  106 , locking element  142  or keeper assembly  113 . 
   The invention has been described with particular reference to the preferred embodiments thereof, but it should be understood that variations and modifications within the spirit and scope of the invention may occur to those skilled in the art to which the invention pertains.