Abstract:
A sliding door latching and locking system is disclosed which includes a latch assembly, a lift rod assembly, and a retainer assembly, among other things. In some embodiments, the latch assembly includes a support member mounted in a movable body and a latching arm pivotally mounted to the support member having a distal end thereof extending outside of the periphery of the movable body, wherein the distal end includes an engagement facilitating portion with a sloped outer surface for contacting an interlocking member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application claims priority to U.S. Provisional Application No. 61/374,545 filed Aug. 17, 2010, the disclosure of which is incorporated herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Horizontal sliding doors, which actually may slide or roll, usually include one or more door panels suspended by carriages that travel along an overhead track. The carriages allow the door panels to slide or roll in a generally horizontal direction in front of a doorway to open and close the door. The door may be manually or automatically moved from its open and closed position. Sliding doors such as these are often used with storage structures such as barns. 
     Depending on the width of the doorway and the space along either side of it, a sliding door can assume a variety of configurations. For a relatively narrow doorway with adequate space alongside to receive an opening door panel, a single door panel is typically enough to cover the doorway. Wider doorways with limited side space may require a bi-parting sliding door that includes at least two panels each moving in the same plane in opposite directions from either side of the doorway and meeting at the center of the doorway to close the door. For even wider doorways or those with even less side space, multi-panel sliding doors can be used. Multi-panel doors have at least two parallel door panels that overlay each other at one side of the doorway when the door is open. To close the door, one panel slides out from behind the other as both panels move in front of the doorway to cover a span of about twice the width of a single panel. Applying such an arrangement to both sides of the doorway provides a bi-parting door with multiple panels on each side. 
     If any of these door arrangements are not properly secured, wind damage can occur. In fact, a sudden gust of wind may dislodge the doors from the track or tracks. Such wind damage may also cause deformation or damage to the frame or the door itself in cases where the door is inadequately supported. Thus, a more secure door configuration both in the open position, as well as the closed position is needed, among other things. 
     SUMMARY OF THE INVENTION 
     The invention is generally directed to locking and securing assemblies, which among other things, address the aforementioned needs, simplify the procedures for latching and locking and reduce the steps required to provide access without compromising security. 
     In some embodiments, the invention is directed to a latching and locking system for sliding doors, which generally includes various components, such as a latch assembly, a lifting rod assembly, a door catch and a retainer system. 
     In one embodiment, the latch assembly is designed to add the ability to lock and secure large sliding doors from the exterior as well as the interior of a building by combining multiple functions and actions through a single device. In another embodiment, the locking system includes a latch assembly, which includes a lockset on the exterior, a lifting rod assembly, a door catch, and a retainer system. The door can be unlocked using a key from the exterior of the door. The key immediately releases the handle restriction, and the handle operation unlatches the panels and disengages the lifting rod assembly, so that the operator can walk the panel to the opening jamb, where the door retainer automatically latches the panel in the open position. The lifting rod assembly is normally in the lower position so that it does not affect travel along the upper trolley track. When the handle is turned by the user, the lift bolt is raised up into the track and at that point it pushes the latch plate mechanism up and over the door stop that has latched the door in place. The door can be unlocked from the interior without a key. If the door is a double paneled door, the same operation is done for the second door. 
     For the door to close, the retainer must be released and the door slides and stops due to a stop at the end of the trolley travel, so that the panel remains in the closed position. The retainer catch serves to draw the door in tighter against the building and prevent the door from being pulled away in high winds. When in the closed position, the latch plate mechanism in the trolley stops on a door stop in the trolley track above the door header. In the single panel configuration, the latch assembly primary purpose is to prevent the door from opening. If the door has two panels, a similar door stop will stop each door, and the latch assemblies prevent each door from opening. 
     Some embodiments are directed to a latch assembly which includes: a support member mounted in a movable body, wherein the movable body is mounted on a structural frame for movement in an interior space defined by the structural frame into and between a substantially open position and a substantially closed position; a latching arm, including a proximal end pivotally mounted to the support member and configured to be biased toward a starting position, an intermediate section extending through an aperture in the movable body to a position adjacent to the periphery of the movable body, a distal end adjacent to the periphery of the movable body including an engagement facilitating portion extending in a substantially transverse direction with respect to the longitudinal axis of the intermediate section, the engagement facilitating portion having a sloped outer surface, wherein the engagement facilitating portion and intermediate section define a receiving space adjacent thereto; and an interlocking member extending in an opposing direction with respect to the engagement facilitating portion, wherein movement of the movable body into the closed position causes the interlocking member to contact the sloped outer surface of the engagement facilitating portion, the latching arm being responsive to the contact between the sloped outer surface of the engagement facilitating portion and the interlocking member by pivoting from the starting position and returning to the starting position upon the interlocking member being received by the receiving space. 
     In some embodiments, the movable body is a sliding door. 
     In some embodiments, the engagement facilitating portion has a triangular cross-sectional profile. In some embodiments, the engagement facilitating member includes an upper outer surface and a lower outer surface, wherein the upper and lower surfaces are sloped at substantially similar opposing slopes. 
     In some embodiments, the latching arm is operatively associated with at least one handle extending adjacent to the exterior of the movable body, wherein the latching arm pivots from the starting position in response to movement of the handle. 
     In some embodiments, the aforementioned latch assembly further includes a locking member configured for being set in an activated condition and a deactivated condition from the exterior of the movable body, wherein the locking member blocks pivotal movement of the latching arm upon being set in the activated condition and allows pivotal movement of the latching arm upon being set in the deactivated condition. 
     In some embodiments, the interlocking member further comprises a sloped outer surface at a substantially similar opposing slope with respect to the sloped outer surface of the engagement facilitating portion. In some embodiments, the interlocking member is part of a substantially similar opposing latching arm. 
     In some embodiments, the opposing latching arm is operatively associated with a support member mounted in a substantially similar opposing movable body mounted for movement in the interior space. 
     Some embodiments of the invention are also directed to a latch assembly which includes: a support member mounted in a sliding door body, wherein the sliding door body is mounted on a door frame for movement in an interior space defined by the door frame, into and between a substantially open position and a substantially closed position; a latching arm, including a proximal end pivotally mounted to the support member and configured to be biased toward a starting position, an intermediate section extending through an aperture in the movable body to a position adjacent to the periphery of the sliding door body, a distal end adjacent to the periphery of the movable body including an engagement facilitating portion extending in a substantially transverse direction with respect to the longitudinal axis of the intermediate section, the engagement facilitating portion having a sloped outer surface, wherein the engagement facilitating portion and intermediate section define a receiving space adjacent thereto; an interlocking member extending in an opposing direction with respect to the engagement facilitating portion, wherein movement of the sliding door body into the closed position causes the interlocking member to contact the sloped outer surface of the engagement facilitating portion, the latching arm being responsive to the contact between the sloped outer surface of the engagement facilitating portion and the interlocking member by pivoting from the starting position and returning to the starting position upon the interlocking member being received by the receiving space; and at least one handle extending adjacent to the exterior of the sliding door body operatively associated with the latching arm, wherein the latching arm pivots from the starting position in response to pivotal movement of the handle. 
     The latch assembly described above may further include a locking member configured for being set in an activated condition and a deactivated condition from the exterior of the movable body, wherein the locking member blocks pivotal movement of the latching arm upon being set in the activated condition and allows pivotal movement of the latching arm upon being set in the deactivated condition. 
     In some embodiments, the interlocking member may be part of a substantially similar opposing latching arm. The opposing latching arm may be operatively associated with a support member mounted in a substantially similar opposing sliding door mounted for movement in the interior space. The opposing latching arm is operatively associated with a support member mounted in the door frame. The interlocking member may be connected with the door frame. 
     Some embodiments of the invention are also directed to a latching retainer device attached to the jamb of a sliding door which extends outward from the jamb into the frame area in the central part of the door that engages a catch near the edge of the door that is beside the opening jamb when the door is closed. This latching device secures the panel at the jamb when the panel is fully closed. 
     In some embodiments, the aforementioned latching retainer device engages a ramp type bracket attached to the door panel and small rollers on the latching retainer device engage the ramp to slide the device away from the door and along the side of the jamb to allow the vertical frame members of the panel to pass by the retainer device. 
     In some embodiments, the latching retainer device is actuated by a spring device to keep pressure on the retainer so that it is forced outward at all times unless the force is overcome by the ramp attached to the door panel and drives the retainer backward to allow the vertical members of the panel to slide past the retainer. 
     In some embodiments, the latching retainer device includes an adjustment feature to position the end of the retainer in the correct location to engage the catch and the ramps. 
     In some embodiments, the latching retainer device is attached to the jamb of a sliding door which extends outward from the jamb into the frame area in the central part of the door and which drives outward after the vertical member at the edge of the panel has passed the edge of the jamb and latches the door in the open position, which among other things, facilitates a non-friction positive capture of the open panel such that the door cannot slip back partially into the opening and hence be vulnerable to wind damage. 
     In some embodiments, a latch mounted in a door track is capable of being actuated from the inside of the door by use of the internal latch handle that actuates a lift rod assembly by means of a cable. 
     These and other aspects of the invention and various embodiments thereof will become more readily apparent to those having ordinary skill in the art from the following detailed description of the invention and some embodiments thereof taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that those having ordinary skill in the art to which at least some embodiments of the invention pertains will more readily understand how to make and use systems, devices and methods in accordance therewith, such embodiments thereof will be described in enabling detail herein below with reference to the drawings. It should be noted that the drawings are not necessarily drawn to scale and certain figures may be shown in other form for illustrative reasons. 
         FIG. 1  is a front view of a building with a double sliding door in the closed position which includes a door latch according to the present disclosure. 
         FIG. 2  is a front view of a building with a double sliding door in the open position which includes a door latch according to the present disclosure. 
         FIG. 3A  is a close up perspective view of the door latch, as installed into the sliding door, showing a protruding hooked door latch extension. 
         FIG. 3B  is a perspective view of the single door catch plate. 
         FIG. 4  is a close up perspective view of the interior side of the sliding door showing the matched protruding hooked door latch extension. 
         FIG. 5A  is an exterior view of the door latch assembly. 
         FIG. 5B  is an interior view of the door latch assembly with side plate removed. 
         FIG. 6  is a front view of the door latch assembly. 
         FIG. 7A  is an interior view of the door latch assembly with an outer panel of the housing removed. 
         FIG. 7B  is a perspective view of the door latch assembly mounted into the door frame. 
         FIG. 8  is a top view of the door latch assembly. 
         FIG. 9  is an exploded view of  FIG. 1  door latch assembly. 
         FIG. 10  is a perspective view of the hooked door latch. 
         FIG. 11A  is a side view of the hooked door latches in their locked configuration. 
         FIG. 11B  is a perspective view of the hooked door latches as formed for use in the locked configuration. 
         FIG. 12  is an exterior view of the latch assembly with lift rod assembly utilizing a cable for their interconnection on the interior of a door. 
         FIG. 12A  is a magnified view of latch assembly with cable interconnection. 
         FIG. 13  is an exterior view of the door magnifying the lift rod assembly utilizing a cable for the interconnection with door latch assembly. 
         FIG. 13A  is a magnified view of lift rod and plate latch mechanism. 
         FIG. 14  is an exterior view of the lift rod assembly with the door frame missing. 
         FIG. 15  is an exterior view of the lift rod assembly movement within the track. 
         FIG. 16  is a perspective view of the trolley track illustrating the secondary stop. 
         FIG. 17  is an interior view of the retainer and the retainer catch. 
         FIG. 17A  is a magnified view of retainer and retainer catch. 
         FIG. 18A  is a bottom view of the retainer. 
         FIG. 18B  is a perspective view of the retainer. 
         FIG. 19  is an interior view of the door including the retainer catch. 
         FIG. 19A  is a magnified view of the retainer catch. 
         FIG. 20  is a perspective view of the retainer catch. 
         FIG. 21  is an interior view of the door including the retainer ramp. 
         FIG. 21A  is a magnified view of the retainer ramp. 
     
    
    
     DETAILED DESCRIPTION 
     The following description contains illustrations of devices, systems and methods according to the invention for purposes of promoting an understanding of embodiments the invention, among other things. It should be understood that the scope of the invention is not limited by these embodiments. Alterations and modifications of the features of the invention, as well as additional applications of its principles in other forms or embodiments, such as those which would normally occur to one skilled in the relevant art having possession of this disclosure, are to be considered within the scope of the invention. 
     Referring now to  FIGS. 1 and 2 , there is illustrated a building  10  with a double sliding door which includes a first sliding door  11 , a second sliding door  12 , and a latch assembly constructed in accordance with an embodiment of the invention. In this embodiment, the latch assembly includes a right handed door latch assembly  13  which is assembled into the first sliding door  11 , and a left handed door latch assembly  14  which is assembled into the second sliding door  12 . As illustrated, the two doors  11  and  12  are drawn together into close proximity such that their inside facing edges are in contact with one another. 
     In an alternative embodiment where there is a single sliding door, the second sliding door  12  is eliminated and the first sliding door  11  slides into a fixed portion of the building  10 . It should be understood that building  10  is not the only form for which the door latch assembly  13  and  14  can be used. There are a wide range of movable doors or similar movable panels, such as sliding windows and partitions, or other configurations in which a latch assembly constructed according to the invention described herein may be employed. 
     In  FIG. 3 , the hook extension  22  is illustrated as it is configured relative to the first sliding door  11  with its abutment surface  25  where the door latch  13  is assembled into the first sliding door  11 . Referring to  FIG. 4 , the interior view of  FIG. 3  is illustrated as assembled and secured into its receiving structure of the sliding door  11  with its abutment surface  25 . As is illustrated, door latch  13  mounts to the inside abutment surface of the sliding door  11  and the inside surface of the first sliding door is a web structure with open spaces for receiving door latch  13  (see  FIGS. 7B and 12 ). In  FIG. 7B , illustrates the mirror image of  FIG. 3 . The door latch assembly  14  is positioned as close to the interior of the building as is possible on the web of the vertical support rail  75   
     Referring now to  FIG. 5A , in order to facilitate this sliding door installation, the door latch assembly  13  has an exterior latch side plate  40 , exterior door handle  20 , keyed lock  21 , cable  41 , spring  42 , inside latch handle cover  43 , lock plate bracket  44 , latch hook  45 , interior latch side plate  46 , latch pivot arm  47 , and an inside latch handle  62 . The lock plate bracket  44  is riveted to side plate  40 . The housing is generally connected via bolts with spacers to maintain consistent spacing. Bolts provide added rigidity to housing and some degree of enclosing protection for the components assembled in between exterior side plate  40  and  50  and interior side plate  46  and  56 . As such, the size and location of the bolts can be changed depending on the design preferences and the anticipated receiving door structure. 
     Referring now to  FIGS. 5A through 9 , there is illustrated a door latch assembly  13  configured as a subassembly prior to being installed into the first sliding door  11 . Door latch assembly  13  includes a key-operable lock  21  whose use will be illustrated herein below. However, the key operable lock  21  has been removed from  FIGS. 5B-8  in order to more clearly illustrate the other components and interior construction of door latch assembly  13 . 
     The main securing of the door is formed with a latch hook  55 , an exterior door handle  30 , an optional interior door handle for use in some alternative embodiments or location therefor  90 , an inside latch handle  72 , pin  72 A, key-operable lock  31 , latch pivot side plate  73 , latch pivot wheel  74 , inside lock pivot  58 , lock arm  70 , lock spring  59 , and a latch pivot arm  57 . The locking function relies on a notched lock arm  70  that rotates into place with the notch  75  covering a pin connected to the inside latch handle  72 . The lock arm  70  is secured by a bolt that runs through side plate  50  and  56  and the pivot point of the lock arm  70 . When the notch  75  in the lock arm  70  covers the pin, the inside latch handle  72  is prevented from being able to rotate. Latch hook  55  connected to the inside latch handle  72  through the latch pivot wheel  74  and latch pivot arm  57  is in a position that will allow it to stay latched or allow the latching action to occur. When the lever is prevented from rotating, the interior and exterior handles will not actuate, thus locking the door. 
     The lock arm  70  maintains pressure over the top of the pin by means of a lock spring  59  attached to the opposite end from the notch on the lock arm. The securing of the latch assembly  14  is spring biased, with lock spring  59  tending to pull the lock arm  70  in a downward direction. The moment imparted to the lock arm  70  ensures that the locking function stays secure over the pin unless acted upon by the pivoting inside lock pivot  58 . The inside lock pivot  58  is constructed such that its cylindrical body has a half circle section protruding from the body. The inside lock pivot  58  operates in two positions. In the locked position it allows the lock arm  70  to rest flat across inside lock pivot  58 , such that the notch  75  in the lock arm  70  rests over the pin in the inside latch handle  72 . In the second unlocked position, as the inside lock pivot  58  rotates into the unlocked position it acts as a cam pushing up against the spring force of the lock arm  70  and raising it up so that there is enough clearance for the pin on the inside latch handle  72  to pass freely beneath the notch and allows actuation of the latching mechanism. 
     In this embodiment, the inside lock pivot  58  can be rotated by either of two methods. The first method is operated from the exterior of the building. It relies on a key operable lock  31  that is attached to the lock plate bracket  54 . The key operable lock  31  protrudes from the interior of the door to the exterior of the door. As the door operator turns the key the key operable lock  31  rotates the inside lock pivot  58 . The second method of rotating the inside lock pivot  58  is achieved from the interior side of the door. This method rotates the inside lock pivot  58  by means of a lever  58 A directly attached to the inside lock pivot  58 . 
     The exterior rotation of a key in the key operable lock  31  or the rotation of the inside lock pivot  58  from the interior forces the lock arm to release the inside latch handle  72 . With the lock arm released, this allows for the rotation of either the interior or exterior latch handle to rotate. The exterior door handle  30  is mounted in the bushings that are pressed into the latch assembly  13  housing made up of side plate  50  and  56 . Exterior door handle  30  extends through a hole so as to permit pivoting movement of the latch hook  55 . The inside latch handle  72  is mounted on and connected to the exterior door handle  30  and interior door handle. This configuration of exterior handle rod  30  allows the rod to freely turn or rotate within the receiving holes in the outer and inner panels  50  and  56 . Connecting them in this way also allows both the inside latch handle  72  and exterior door handle  30  to rotate around the same axis together, so rotating one handle will also rotate the other handle once the lock arm  70  has been disengaged. 
     Once lock arm  70  is released, the rotation of either handle rotates the inside latch handle  72 , which rotates a cam called the latch pivot wheel  74 , this cam rotates pin  72 A, and pin  72 A pushes the latch pivot arm  57  forward and up, thus lifting the latch hook  55  up and over the latch hook  45 . The inside latch handle  72  is connected to the latch hook  55  by means of the latch pivot wheel  74 . As the latch pivot wheel  74  continues to rotate, pin  72 A connected to the bottom of inside latch handle  72  and comes into contact with the latch pivot arm  57  pushing the latch hook  55  up and over the other latch hook  45  as the lever completes its rotation. This allows the operator to pull the door open because both the lock arm  70  and the latch hook  55  connected to the inside latch handle  72  are clear of their respective catches. The interior side of the latch assembly  14  does not have a keyed lock like the exterior, but instead it has an inside lock pivot  58 . In an alternative embodiment, the optional interior door handle  90  may be added, if for example, access to the inside latch handle cover  53  is limited. 
     The latch hook  45  is one of the component parts in the door latch assembly  13 , and the latch hook  55  is one of the component parts in the door latch assembly  14 . When the two sliding doors are drawn together, either latch hook is lifted up and inserted into clearance slot  34  and  24  (see  FIG. 12 ). The door cannot slide apart without either latch hook  45  or  55  being lifted to a height where the sliding apart movement is not hindered by the back side of the ramped surface  23 . Either hook extension can be released when the door handle is rotated. If exterior door handle  20  is rotated, the latch hook  45  lifts up and the sliding door  11  becomes unlatched from sliding door  12 . Alternatively, in order to latch the arms, the latch hook  45  is lifted by the ramped surface  33  of the latch hook  55  and slides into clearance slot  34  and completes the securing together of the two doors  11  and  12 . 
     Referring now to  FIG. 3B , an alternative embodiment includes a stationary single door catch plate  14 A secured to the abutment surface of a building, such as the surface of the door jamb, in a position for receiving the latch hook  45 . When the single sliding door is drawn towards the building surface, latch hook  45  is lifted up over surface  55 A through contact between surface  23  and surface  55 A as the door is moving thereto, and latch hook  45  falls into place within clearance slot  34 A with surface  55 A accommodated by clearance slot  24 . The single sliding door cannot slide without latch hook  45  being lifted to a height where the sliding apart movement is not hindered by the back side of curved surface  33 A. Latch hook  45  can be released when the door handle  20  is rotated, and the latch hook  45  lifts up and the sliding door  11  becomes unlatched from the stationary single door catch plate  14 A. 
     Referring now to  FIG. 10 through 11B , latch hook  45  is comprised of connecting slot  26 , edge portion  25 , clearance slot  24 , hook extension  22 , ramped surface  23 . The latch hook is separated into 3 parts: front, intermediate, and end portions. In  FIG. 10 , the front end of latch hook  45  has a double sided angled ramp that allows either hooks to slide over the top of each other as they come in contact. The intermediate portion of latch  45  where the hook extension  22  is, determines the length of the hooked front portion. The edge portion  25  is not as long as the front hooked portion, and this portion includes a connecting slot  26  that connects to latch pivot arm  48  via a bolt. In  FIGS. 11A and 11B , once a latch hook has slid over the top of the matching component it falls behind the front of the latch hook into clearance slot  24  and  34  and this forms a catch. The back face of the front ramped surface  23  hooks to the back surface of ramped surface  33  to form the catch. As see in  FIG. 11B , the latch hooks are parallel to each other, and the clearance slot  24  can be a tighter fit to prevent doors from sliding back and forth, which would secures the door in place. 
     In another embodiment, the door is secured by two latch mechanisms: the latch assembly  14  and the overhead track latching mechanism. The overhead track latching mechanism is comprised of the latch mechanism plate  131  and the lift rod assembly  16 . In  FIG. 7A , the lift rod assembly is attached to the inside latch handle  72 , by means of wheel pulley  71 , cable  51 , and cable spring  52 .  FIG. 13  shows sliding door  12 , and the cable system that attaches to the overhead track latching mechanism. Cable spring  52  is further connected by cable  51 A to the lift rod assembly  16   
     Referring now to  FIG. 14 through 16 , the lift rod assembly  16  is made up of: cable  51 B, pulley wheel  111  and  111 A, pulley bracket  110  and  110 A, compression spring  112 , rod  113 , bolt end  114 , overhead track  200 , secondary stop  130 , latch mechanism plate  131 , track wheel assembly  132 , support rod  136 , and ramp wheel  133 . The door is primarily stopped by the center door guide in the closed position. 
     In this embodiment as shown in  FIG. 13 , the left handed sliding door lift rod assembly  16  works in conjunction with the latch assembly  14  to secure the door when the latching mechanism plate  131  slides over a secondary stop  130  by means of its ramp face  134  by falling into a catch created by the secondary stop  130 . 
     The latch mechanism is attached to inside the overhead track  200  connecting the sliding door  12  by means of a support rod  136 . The latch mechanism plate  131  hooks around the axel of the trolley wheel assembly  132  on one side and has a ramp face  134  on the other side. The ramp face  134  has a ramp wheel  133  to allow it to roll easily through the track. There is a secondary stop  130  fixed in the track (see  FIG. 17 ). As sliding door  12  is sliding closed, the ramped end of latch mechanism plate  131  is forced up and over the secondary stop  130 . Behind secondary stop  130  is a space that acts as a catch. As the ramp face  134  slides via the ramp wheel  133  up and over the stop, as the latch mechanism plate  131  is still secured to the trolley. As the ramp face  134  passes the secondary stop  130  gravity pulls it down securing it. The latching mechanism plate  131  is secured by secondary stop  130  and because it is also secured to the trolley wheel assembly  132  at the axle, sliding door  12  is prevented from traveling along the track 
     The compression spring  112  in the lift rod assembly  16  also serves the purpose keeping the bolt in a starting position. The bolt  113  is normally down and out of the overhead track  200 , so that sliding door  12  can move freely in between the open and closed positions. To unlatch the in track latch mechanism plate  131  from the secondary stop  130 , either interior or exterior door handle needs to be rotated. This action rotates the inside latch handle  72 , which connects via cable  51  through a system of pulleys to the compressions spring  112  in the lift rod assembly  16 . The wheel pulley  71  and the pulley wheel  111 , and  111 A are each connected by a cable  51 . Pulley wheel  111  and  111 A are faceted by means of the pulley assembly to vertical  75  and top horizontal beam of sliding door  12 , respectively. Cable  51 B draws a spring loaded bolt  113  up and into the track (See  FIG. 16 ). The bolt end  114  of the spring loaded bolt  113  in the lift rod assembly  16  pushes the latch mechanism plate  131  via lower portion  135  in the overhead track  200  up and over the secondary stop  130  so that the trolley wheel assembly  132  and latch mechanism plate can be released, and the door  12  can continue to slide along the overhead track  200 . 
     The cable spring  52  attached to the cable  51  that connects the inside latch handle  72  to the spring loaded bolt  113 . The cable spring  52  is preferably stiffer than the compression spring  112  in spring loaded bolt  113 . The stiffer cable spring  52  allows it to act as a part of the cable in transferring force to unlatch the sliding door  12  in the track. The inside latch handle  72  may be designed to rotate farther than necessary to help ensure the latch assembly  14  unlatches. Once the inside latch handle  72  has pulled the cable  51  far enough that the bolt  113  can no longer travel upward, the stiffer cable spring  52  will extend. This protects cable  51  from damage in over-rotating the lever, among other things 
     In another embodiment, the operation of unlocking the latch mechanism plate  131  relies upon pressurized air to provide the force necessary for actuating the in track lift rod assembly  16 . The pneumatic method of operation for the lift rod assembly  16  replaces mechanically actuated lift rod assemblies  16 . An exterior and interior handle may operate the latch hooks as described by the pulley system. However, instead of pulling on a cable attached to pulleys, the handle compresses air in a cylinder as it is actuated. This compressed air operates a pneumatic cylinder at the top of the sliding door  12  and is directed to push the latch mechanism plate  131  up and over the secondary stop  130 . The rod end  114  pushes the latch mechanism plate  131  up and over the secondary stop  130  (see  FIG. 15 ). As the handle that operates the compression cylinder returns to the starting position, the pressure in the compression cylinder reduces and the lift rod cylinder is allowed to return down and into the starting position. In some embodiments, it is envisioned that the air pressure that returns the compression cylinder to the starting position will also return the inside latch handle  72  and therefore the latch hook  55  to their nominal positions. In other embodiments, the cylinder may be of an internal spring return type or a standard pneumatic cylinder used to power the lift rod cylinder. 
     In another embodiment, the door is further secured by another latch mechanism, that is, a retaining subsystem. The retaining subsystem of this embodiment is comprised of retainer assembly  18 , retainer ramp  2 , and a retainer catch  4 . The retaining function serves to keep sliding door  12  in the fully open position and prevent the door from sliding along the track. In a bi-panel two sliding door configuration, there may be two such retaining sub systems. The retainer assembly works in conjunction with a retainer roller ramp and a door catch to create a secure latch. 
     Referring now to  FIG. 17  through  FIG. 18B , the retainer assembly is a spring loaded retainer bolt  155  mechanism attached to the door jamb  150 . The retainer is comprised of: retainer roller  151  and  151 A, extrusion housing  152 , retainer end cap  153  and  153 A, mounting point  153 B, nylock nut  154 , press fit bushing  154 A, retainer bolt  155 , retainer pin  156 , retainer compression spring  157 , e-clip  158  and  158 A, and a retainer roller pin  159   
     The exterior facing retainer end cap  153  has a polygonal hole for the hex bolt to pass through and prevent rotation along the axis of the retainer bolt  155 . A retainer pin  156  is inserted at the end of the cylindrical portion of the retainer bolt  155  perpendicular to the axis of the bolt, but parallel to the door jamb  150  in order to act as a handle for unlocking the mechanism. The polygonal side of the retainer bolt  155  extends past the door jamb  150  into the sliding door between horizontal support rails of the sliding door  12 . That end of the retainer bolt  155  has the retainer roller pin  159  inserted through a hole near the tip that is perpendicular to the axis of the bolt and parallel to the door jamb  150 . The retainer roller pin  159  is inserted to the end of the polygonal side of the retainer bolt  155  and serves as an axel for the retainer roller  151  and  151 A. One roller is attached to each side of the retainer bolt  155  via e-clip  158  and  158 A. E-clip  158  and  158 A are used to retain the rollers on the retainer roller pin. Retainer roller  151  and  151 A are free to spin around the axis of the retainer roller pin  159  on which they are mounted. 
     The retainer compression spring  157  allows retainer bolt  155  to move freely in and out. The retainer bolt  155  is pushed out in the direction of the exterior of the building by the spring force and when fully extended it would be considered the starting position for the retainer bolt  155 . The retainer bolt  155  should not be circular in nature so as to prevent the bolt from rotating within the retainer assembly, it is envisioned to be polygonal, for example: a triangle, square, pentagon, oval, composite or oblong shape all could be used to prevent rotation. In  FIGS. 18A and 18B , illustrates the retainer bolt  155  with a hexagonal shaped end and a circular shaped end. The retainer end cap  153  prevents the retainer bolt  155  from rotation by providing a track or channel in the polygonal shape that the retainer bolt  155  travels through. To mount the entire retainer assembly the retainer end caps  153  and  153 A have slots that serve as mounting points so that the retainer assembly  18  can be attached to the door jamb  150 . Mounting point  153 B is illustrated. 
     The end of the retainer bolt  155  that faces the interior of the building is threaded to provide adjustment in and out by rotating the nylock nut  154  that presses against the press fit bushing  154 A and end cap  153 A. This adjustment allows the end of the retainer bolt  155  facing the exterior of the building to stick out an optimum distance past the door jamb  150 . The press fit bushing  154 A is flange shaped to help ensure the threaded portion of the retainer bolt  155  will not become jammed against interior retainer end cap  153 A. The retainer roller  151  and  151 A do not have to touch the interior of the sliding door  12 . The housing of the retainer assembly  18  consists of an extrusion  152  with a retainer end cap  153  and  153 A fastened to each side (see  FIGS. 18A and 18B ). The interior facing end cap has a round hole with a bushing pressed into it. The retainer bolt  155  passes through the bushing to allow smooth linear motion for the bolt to move in and out. 
     Referring now to  FIGS. 19 and 20 , which illustrate a retainer catch  4  and a vertical support beam  75 B designed to be used with the retainer assembly in order to prevent the door from pulling away from the building while the door is in the closed position, among other things, constructed according to some embodiments of the invention. 
     In this embodiment, the retainer catch  4  is mounted in the web of vertical support beams via eight slots or holes (similar to slot  4 A in  FIG. 20 ) on the vertical support rail  75 A opposite the vertical support rail  75  which contains the latch assembly  14 . The retainer assembly  18  is provided additional rigidity through the vertical support rail  75 B attached to the other end of retainer catch  4 . The additional vertical support beam  75 B is secured between two horizontal supports parallel to the vertical support rail  75 A and positioned near the end of the retainer catch  4 . 
     The retainer catch  4  is made up of two bent plates, called retainer catch plate  160  and  161  that create a gap between them facing the interior of the building  10  when riveted together. The track  162  between the retainer catch plate  160  and  161  create an angled track on which the retainer roller  151  and  151 A of the retainer assembly  18  are guided. The retainer catch  4  is positioned vertically so that the horizontal plane that lies at the center of the track  162  is parallel to the axis of the retainer bolt  155  in the retainer assembly  18 . 
     The retainer roller  151  and  151 A of the retainer assembly  18  are positioned farther into the door than the leading edge of the track  162  created by the retainer catch  4 . As the sliding door  12  moves toward the closed position, the inside surface of the retainer catch track  162  comes in contact with retainer roller  151  and  151 A of the retainer assembly  18 . The retainer catch  4  is angled opposite of the retainer ramp  2  so that as the sliding door  12  moves toward being fully closed the door is drawn in toward the door jam  150  (see  FIG. 19 ). 
     In the fully closed position the retainer catch  4  and retainer assembly  18  prevent the door from moving away from building  10  due to wind or other forces. The retainer catch  4  holds the sliding door  12  close to the door jam  150  to secure the sliding door  12  from moving away from building  10 . To remove the sliding door  12  from the retainer catch  4 , the door operator simply needs to unlatch or move the sliding door  12  along the track toward the open position. Once the sliding door  12  has moved the retainer catch  4  past the retainer roller  151  and  151 A of the retainer assembly  18 , the retainer catch  4  will no longer function to retain the door from moving away from the building. 
     Referring now to  FIG. 21 , the retainer ramp  2  is designed to push the retainer bolt  155  back, such that it will spring forward once the leading edge of the door has passed. The purpose of this is not to prevent sliding door  12  from being pulled away from the building, but rather to prevent sliding door  12  from sliding back along the track. Therefore, the retainer bolt  155  impedes the door path back along the track. The retainer ramp  2  is positioned inside the door in the web of horizontal and vertical members. It is illustrated as mounted against the vertical support rail  75  that contains the latching system. The retainer ramp  2  is positioned at a height at which the horizontal plane at the center of the ramp plate lies parallel to the axis of the retainer bolt  155 . The retainer ramp  2  is positioned so that the end of the ramp incline is flush with the interior surface at the edge of the sliding door  12  and the retainer ramp  2  decline leads to the interior of the door. The retainer ramp  2 , which is flush to the interior edge of sliding door  12  on one side, is angled in the direction of the exterior of the sliding door  12  on the other side. In this embodiment, the far end of retainer ramp  2  lies farther into the sliding door  2  than the retainer bolt  55  that extends into the door. 
     The retainer roller  151  and  151 A catch the retainer ramp  2  as the door closes. The retainer ramp  2  connected to the sliding door  12  contacts the retainer roller  151  and  151 A at the end of the retainer assembly  18 . As sliding door  12  moves toward the fully open position the retainer ramp  2  pushes in the spring loaded bolt  155 . Once the retainer ramp  2  and the inside edge of the vertical support rail  75  have passed the retainer roller  151  and  151 A, there is no longer any force to hold the retainer bolt  155  back and so it will spring forward returning to the starting position. At this point sliding door  12  is retained in the open position as the extended retainer  155  bolt impedes the sliding door  12  from traveling along the track. 
     In the fully closed position retainer assembly  18  prevents the door from moving away from building  10  due to wind or other forces. In the fully open position retainer assembly  18  prevents the door from moving toward the closed position along the track. To release the sliding door  12  from the fully open position the door operator must physically push the retainer pin  156  of the retainer assembly  18  in toward the interior of the building, using it like a handle. Once the operator has pushed the retainer pin  156  far enough back so that the rollers no longer impede the closing of the sliding door  12 , the operator can then pull the sliding door  12  into the closed position. Once the edge of the sliding door  12  has moved sufficiently far enough to the closed position that retainer roller  151  and  151 A do not spring back to impede the travel of the sliding door  12 , the operator can release the retainer pin  156  and allow the spring loaded retainer bolt  155  to return to the starting position. At this point the sliding door  12  is free to move along the overhead track  200 . 
     It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. Indeed, many modifications and variations of the embodiments of the invention are possible in light of the above teachings, and the invention may be practiced otherwise than as specifically described yet remain within the scope of the appended claims and equivalents thereof. 
     While exemplary methods, systems, devices and applications thereof of the present disclosure, have been described herein, it should also be understood that the foregoing is only illustrative of exemplary embodiments, as well as principles of the invention, and that various modifications can be made by those skilled in the art without departing from the scope and spirit of the invention. Various modifications to these embodiments will be readily apparent to those skilled in the relevant art, and principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown and described herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically stated, but rather “one or more.” All structural and functional equivalents to the elements of the various embodiments described throughout this disclosure that are known or later come to be known to those of ordinary skill in the relevant art are expressly incorporated herein by reference and intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims.