Abstract:
The present invention relates to a latching device for a slide rod system incorporated into a door. The latching device includes a keeper plate engaged to the slide rod, a positioning bracket engaged to a door, and a roller bracket having a roller adapted for engagement to the positioning bracket and the keeper plate. The slide rod and keeper plate are adapted for positioning within a slide channel. The roller bracket is adapted for engagement to a doorframe channel. The positioning bracket includes a slot which receives the roller whereupon the keeper plate is at least partially manipulated vertically to maneuver the keeper to the rear of the roller to accomplish latching of a door.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to control mechanism for use with a swing handle and flat rod system to latch a flat or slide rod within a bracket engaged to a door channel, to secure a metal door. 
     In the past, the known pivot lever bars, flat rods, and/or slide rods were used in conjunction with conventional latching devices where a portion of a slide rod would penetrate into a receiving slot to secure a metal door in a closed position relative to a doorframe. 
     The engagement of a portion of the slide rod within a receiving slot deterred the opening of the door in the absence of the manipulation of the swing handle. The problem with the known slide rod latching devices involved the lack of reliability and/or performance during prolonged use within a metal door. Use of the known slide rod latching devices frequently resulted in the undesirable bending of the slide rod, which in turn caused the distal end of the slide rod to deviate from alignment with the receiving slot of the latch. The failure of alignment between the distal end of the slide rod and the receiving slot of the latch rendered a door unlatchable relative to a doorframe. 
     One problem with the known prior art devices involved the rod guide and the latch point being located at different positions along a Y axis for the rod system. The separation of the rod guide from the latch point frequently permitted a door to flex at locations between the rod guide and the latch point. The known rod systems which separated the rod guide from the latch point placed an undesirable load on the rod system causing the rod system to flex during use. The flexing of the door, the placement of load on the rod system, and the flexing of the rod system, frequently caused damage to either the door or the rod system, rendering use of the door and rod latching system inoperative. 
     Another problem with the rod systems as known involved the difficulty of simultaneous orientation along both the X and Y axis of the rod guide and latch, as well as the door with the doorframe, prior to initiation of force upon the rod system. The lack of proper orientation of the rod guide and latch prior to manipulation of the control or swing handle frequently resulted in damage to either the rod system, the swing handle, and/or the door. In addition, the lack of proper orientation of the rod guide, latch, door and doorframe along the X and Y axis prior to the initiation of force on the rod system increased the wear on the door and rod system, resulting in accelerated maintenance expenses. 
     The misalignment between the rod guide, latch, door and/or doorframe, also frequently caused an operator to exert excessive force on a control handle, which in turn, may have caused the twisting of the rod system, the latch system, and/or the hinge. Damage to the rod guide, latch, door, hinge, and doorframe, frequently resulted. 
     Another problem with the rod latching systems as known involved the necessity to manipulate the rod system vertically into a latching position. The failure of a portion of the rod system, or rod control system during use, thereby increased the risk that the rod system would inadvertently descend due to gravity, separating the slide rod system from the engagement slot. A door would then become easily opened due to the loss of the latching mechanism. 
     These and other drawbacks of the prior art may be overcome by the disclosed invention. 
     A need therefore exists for a control mechanism for a slide rod device which minimizes misalignment between a keeper/stop and a bracket, to provide improved reliability during use in the latching of a door within a doorframe. 
     In general, the control mechanism for a door latch may be used with any desired metal door, or wherever a slide rod, pivot lever bar, and/or flat rod is used to engage a door within a doorframe. 
     BRIEF SUMMARY OF THE INVENTION 
     In general, the invention relates to a latching device incorporating a slide rod engaged to a door, a keeper plate having a keeper engaged to the slide rod, a positioning bracket having a slide channel and a roller slot engaged to the door, the slide channel receiving the slide rod, and a roller bracket having a roller engaged to a door channel, where the roller slot receives the roller and the keeper releasably engages the roller during the latching of a door within a door channel. 
     In general, the rod slide defines a vertical plane where the roller slot engages the roller substantially orthogonally relative to the vertical plane. 
     In general, the roller as engaged to the roller bracket is disposed substantially orthogonally relative to the vertical plane defined by the slide rod. 
     The invention may also include a keeper plate which is at least partially disposed in the slide channel of the positioning bracket when the keeper is engaged to the roller. 
     In general, the keeper of the keeper plate is adapted for positioning rearwardly with respect to the roller, being disposed between the roller and the back wall of the doorframe channel. 
     The keeper may include opposite ends, where each opposite end includes a beveled edge to facilitate positioning behind the roller during latching of the door. 
     In general, the keeper may be substantially perpendicular to the keeper plate. 
     The invention may include a positioning bracket having at least one bridge which forms at least a portion of the roller slot. 
     In general, the bridge also at least partially defines a keeper channel which is used to facilitate vertical manipulation of the slide rod for positioning of the keeper either proximate or distal to the positioning bracket during the latching or unlatching of a door. 
     The control mechanism may include a first release position where the keeper is disengaged from the roller. 
     The control mechanism may also include a latch positioned where the keeper is engaged to the roller. 
     In general, the roller bracket includes a roller mount which creates a separation distance between the roller and the back wall of the doorframe channel. 
     The control mechanism may include a slide rod engaged to a door, a keeper plate engaged to the slide rod, and a bracket having a latching member engaged to a door channel where the keeper plate is adapted for releasable engagement to the latching member. 
     In general, the control mechanism may include a slide rod engaged to a door, a keeper plate engaged to the slide rod, and a latching member engaged to a door channel, where the keeper plate is adapted for releasable engagement to the latching member. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is an environmental partial cut-away view of the control mechanism for the door latch. 
         FIG. 2  is a detail environmental partial cut-away and partial exploded view of the control mechanism for the door latch. 
         FIG. 3  is a cross-sectional side view of the control mechanism for the door latch taken along the line  3 - 3  of  FIG. 1 . 
         FIG. 4  is a detail isometric exploded view of a portion of the slide rod and keeper plate. 
         FIG. 4A  is a detail cross-sectional side view of the slide rod and keeper plate taken along the line  4 A- 4 A of  FIG. 4 . 
         FIG. 5  is a detail isometric exploded view of the roller bracket. 
         FIG. 6  is a detail isometric partial phantom line front view of the positioning bracket, keeper plate, and slide rod. 
         FIG. 6A  is detail isometric partial view phantom line end view of the positioning bracket, keeper plate, and slide rod. 
         FIG. 7  is a detail partial cut-away view of the control mechanism for the door latch. 
         FIG. 8  is an isometric partial phantom line view of an alternative embodiment of the control mechanism for door latch. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention may be embodied in many different forms, there are described in detail herein specific embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. 
     For the purposes of this disclosure, likewise numerals in the figures shall refer to like features unless otherwise indicated. 
     Depicted in the figures are various aspects of the invention. Elements depicted in one figure may be combined with, and/or substituted for, elements depicted in another figure as desired. 
     In at least one embodiment of the invention the control mechanism for a door latch is referred to by the numeral  10 . As may be seen in  FIG. 1 , the control mechanism for door latch  10  is used in association with a swing handle  12  as coupled to a swing handle support  14 . The swing handle  12  may include a padlock hasp  18  and/or a lock  16 . The swing handle  12  may also be operatively engaged to a flat or slide rod  20 . 
     The swing handle  12  in some embodiments is constructed for pivotal clockwise or counter clockwise rotation to either elevate or descend the flat or slide rod  20  relative to a door  21  and doorframe channel  24 . The swing handle  12  may be configured for either right or left handed operation at the discretion of a user. 
     In some embodiments, the control mechanism for door latch  10  may be engaged to a metal door  21  and a metal doorframe  24 . The door  21  and doorframe channel  24  may be formed of any material in which a slide or flat rod  20  system is commonly used. 
     In some embodiments, the door  21  is formed of an exterior door surface  22  and a door edge  32 . Likewise, in some embodiments the doorframe channel  24  is formed of a doorframe side wall  26 , a doorframe back wall  28 , and an enclosure  54 . 
     In some embodiments, the swing handle  12  is engaged to a cog (not shown). The cog generally includes a plurality of teeth which are operatively engaged to a series of grooves integral to the flat or slide rod  20 . Rotation of the swing handle  12  thereby imparts rotation to the cog which translates the motion through the teeth to either elevate or descend the flat or slide rod  20 . 
     As may be seen in  FIG. 1 , in some embodiments the control mechanism for door latch  10  is formed of a positioning bracket  48  which is adapted for releasable placement about a roller bracket  34 . The positioning bracket  48  may be attached to the exterior surface  22  of the door  21  by use of fasteners  56  which may be bolts and nuts, screws and/or rivets, or other fastening means including mechanical and/or adhesive fasteners. The positioning bracket  48  may be located adjacent to, but is not required to be in contact with, the interior of the door edge  32 . 
     In one embodiment as depicted in  FIG. 1 , the positioning bracket  48  includes a roller slot  50  as adjacent to, and positioned between, at least one, and preferably two mounting areas  58 . An aperture  60  may traverse each mounting area  58 . A nut  62  may engage a fastener  56  to secure the positioning bracket  48  to the interior of a door  21 . 
     The positioning bracket  48  in at least one embodiment includes a slide channel  64  which slideably receives a portion of the slide rod  20  and the keeper plate  44 . The positioning bracket  48  may include a flat top wall or surface  66  which is preferably adapted for flush engagement to the interior of a door  21 . 
     As may be seen in  FIG. 1 , in some embodiments, the control mechanism for door latch  10  includes a roller bracket  34 . The roller bracket  34  is positioned in a doorframe channel  24 . The roller bracket  34  is preferably attached to the back wall  28  of the doorframe channel  24  through the use of fasteners  56  which may be bolts, nuts  62 , screws, rivets and/or any other mechanical, chemical or adhesive fastening means. The roller bracket  34  may include at least one mounting area  68 , which in turn may have an affixation aperture  70 . ( FIG. 2 ) 
     In some embodiments, the roller bracket  34  includes a roller mount  36  which may include a pin aperture  72  adapted to receive a roller pin  38 . 
     As may be seen in  FIG. 1 , in some embodiments, the flat or slide rod  20  includes a plurality of adjacent and regularly spaced positioning slots  30  which are adapted for the engagement of a keeper plate  44  to the flat or slide rod  20 . The flat or slide rod  20  defines a plane of substantially linear motion identified by reference letter A. The manipulation of the swing handle  12  imparts movement to either elevate or descend the slide rod  20  relative to the control mechanism for door latch  10 , and to thereby either elevate or drop the position of the keeper plate  44  relative to the positioning bracket  48  and the roller bracket  34  along plane A. 
     As may be seen in  FIG. 2 , in one embodiment, the keeper plate  44 , the positioning bracket  48 , and the roller bracket  34  are depicted in more detail. 
     As depicted in  FIG. 2 , in one embodiment, the keeper plate  44  is substantially flat, for flush engagement to the flat or slide rod  20 . The keeper plate  44  may include a substantially perpendicular keeper or stop  46 . The keeper or stop  46  may include a pair of opposite edges  76 , which may be beveled to facilitate positioning behind the first and second rollers  40 ,  42  of the roller bracket  34 . 
     In at least one embodiment, the positioning bracket  48  as depicted in  FIG. 2  includes a pair of bracket bridges  52 . The pair of bracket bridges  52 , are preferably separated from each other to define a roller slot  50  therebetween. Each of the bracket bridges  52  may include a positioning ledge  78  as separated from a positioning bracket sidewall  80 . ( FIG. 6A ) The positioning bracket  48  additionally may include a base wall  82 . The space between the positioning bracket sidewall  80 , the positioning ledges  78 , the base wall  82 , and the interior surface of the flat top wall or surface  66  defines the slide channel  64 . ( FIG. 6A ) 
     In at least one embodiment, the positioning of the flat or slide rod  20 , and the keeper plate  44 , within the slide channel  64  is identified by arrow  83  of  FIG. 2 . The positioning bracket  48  and the slide channel  64  support the slideable positioning of the slide rod  20  and the keeper plate  44 , relative to the interior surface of the door  21  and door edge  32 . 
     In some embodiments, as depicted in  FIG. 2 , the roller bracket  34  is securely attached to the doorframe back wall  28  to position the first and second rollers  40 ,  42 , for aligned normal insertion within the roller slot  50 . The roller bracket  34  and a positioning bracket  48  are aligned for coupling therebetween during the latching of a door  21 . 
     In at least one embodiment, as shown in phantom line in  FIG. 2 , the slide rod  20  may be manipulated to elevate the keeper plate  44  vertically along plane A. The vertical manipulation of the keeper plate  44  separates the keeper  44  from a latching position rearwardly of the first and second rollers  40 ,  42  to a first release position. The door  21  and a positioning bracket  48  may then be rotated about a door hinge (not shown) for orthogonal or normal separation of the roller slot  50  from the first and second rollers  40 ,  42 . The slide channel  64  continues to hold the slide rod  20  and keeper plate  44  during the opening of the door  21  and the separation of the positioning bracket  48  from the roller bracket  34 . 
     In at least one embodiment, as depicted in  FIG. 2 , a keeper plate  44  may be manipulated into a latching position, from a first release position, as depicted by the position of the keeper plate  44  shown in phantom line. When the keeper plate  44  and the slide rod  20  have been vertically manipulated to the first release position the door may be rotated about a hinge such that the positioning bracket  48 , and the roller slot  50 , are proximate to the roller bracket  34 . The roller slot  50  is then preferably aligned with the first and second rollers  40 ,  42  for receipt thereof. Once the positioning bracket  48  and the rollers  50  have been orthogonally or normally rotated for surrounding engagement of the first and second rollers  40 ,  42 , the swing handle  12  may be rotated to retract or descend the slide rod  20 , and the keeper plate  44 , for positioning of the keeper or stop  46  rearwardly of the first and second rollers  40 ,  42 . The swing handle  12  may then be closed or locked to retain the keeper or stop  46  in a latching position relative to the roller bracket  34 . 
     In at least one embodiment, the opposite edges  76  of the keeper or stop  46  may be beveled to facilitate the positioning of the keeper  46  rearwardly adjacent to the first and second rollers  40 ,  42 . 
     In some embodiments, the first and second rollers  40 ,  42  have different diameters to facilitate releasable engagement to the keeper  46 . The first and second rollers  40 ,  42  may include bearings to facilitate rotation thereof. The first and second rollers  40 ,  42  are preferably engaged to a roller pin  38  which in turn is attached to the roller mount  36 . The roller pin  38  may extend perpendicularly outward from the forward face of the roller mount  36 . The roller pin  38  is preferably elevated/separated from the doorframe channel back wall  28  to provide a separation distance to permit the slidable positioning of the keeper  46  adjacent to the first and second rollers  40 ,  42 . 
     In some embodiments, the first and second rollers  40 ,  42 , and the roller pin  38 , may be replaced with a pin or rod. The first and second rollers  40 ,  42  and the roller pin  38  may alternatively be replaced with a tab or ledge as extending outwardly from bracket  34 . It should be noted that the roller slot  50  may be any shape as desired to receive a roller, pin, rod, tab, or ledge of the bracket  34 . The roller bracket  34  is therefore not required to include a roller, and a roller slot  50  is not restricted to the receipt of a roller during alignment and coupling of the positioning bracket  48  to bracket  34 . 
     In at least one embodiment it is anticipated that the keeper  46  will releaseable engage a pin, rod, or other latching member  90  including, but not necessarily limited to, a tab or ledge. 
     In at least one embodiment, the positioning bracket  48  and the roller bracket  34  may be modified so that the slide rod  20  may be manipulated to permit the slideable positioning of the keeper  46  rearwardly, with respect to a latching member  90 , to latch a door  21  relative to a door channel  24 . 
     In one embodiment as depicted in  FIG. 3 , the positioning bracket  48  is shown in the latching position relative to the roller bracket  34 . The positioning of the keeper  46  below or rearwardly with respect to the first and second rollers  40 ,  42  functions to prevent rotation and separation of the positioning bracket  48  outwardly away from the roller bracket  34  in an arc of rotation as depicted by arrow B. 
     In at least one embodiment as depicted in  FIG. 3 , the roller bracket  34  is separated from the door channel sidewall  26  within the doorframe channel  24  to provide a space therebetween. As depicted in  FIG. 3 , the mounting bracket side wall  80  is separated from the door edge  32  to provide a space therebetween. 
     In at least one embodiment as depicted in  FIG. 3 , the separation between the top surface of the base wall  82 , and the bottom surface of the positioning ledge  78 , defines the size of the keeper channel  74 . The keeper channel  74  is preferably sufficiently large to permit sliding passage of the keeper  46  therethrough. As depicted in  FIG. 3 , the separation between the interior surface of the side wall  80 , and the interior surface of the positioning ledge  78 , defines the size of the slide channel  64 . The slide channel  64  is preferably sufficiently wide to permit sliding passage of the slide rod  20  and keeper plate  44  therethrough. 
     In some embodiments the first roller  40  and second roller  42  facilitate the slidable positioning of the keeper  46  within channel  74 , for positioning of the keeper  46  rearward to the first and second rollers  40 ,  42 . The first roller  40  and the second roller  42  may each comprise roller bearings to facilitate positioning of the keeper plate  46  relative to the roller bracket  34 . However, the first and second rollers  40 ,  42  are not required to incorporate bearings and may be rotated about roller pin  38 . 
     In at least one embodiment, the roller pin  38  is fixedly secured to the pin aperture  72  of the roller mount  36 . Alternatively, the roller pin  38  may be rotatably positioned within the pin aperture  72  of the roller mount  36 . 
     Referring to  FIGS. 4 and 4A , in at least one embodiment the slide rod  20  includes at least one, and preferably a plurality of, groupings of flat rod positioning slots  30 . One or more groups of flat rod positioning slots  30  may be used to secure a keeper plate  44  to a slide rod  20 . The rearward face of a keeper plate  44  preferably includes at least one, or a plurality of, regularly spaced tangs  84  which are adapted for insertion into individual flat rod positioning slots  30 . The insertion of individual tangs  84  into the flat rod positioning slots  30  frictionally engages the keeper plate  44  to the flat rod  20 . The keeper plate  44  may be fixedly secured and/or releasably attached to the flat or slide rod  20  as desired. The inclusion of groupings of flat rod positioning slots  30  assists to provide flexibility to the control mechanism for door latch  10 , permitting an individual to adjustably engage a keeper plate  44  at a desired location along the flat rod  20 . Standardization of the component of the flat or slide rod  20  may thereby be accomplished. 
     In at least one embodiment, an exploded view of the roller bracket  34  is depicted in  FIG. 5 . A roller pin  38  may have one or more bearing surfaces  86  of differing diameter dimensions to facilitate engagement to one or more different types of first and second rollers  40 ,  42 . The roller pin  38  may include an end shoulder  88  which may be used to retain the first and second rollers  40 ,  42  on the roller pin  38 . The first and second rollers  40 ,  42  may be positioned between the interior surface of the roller mount  36  and the end shoulder  88 . The roller pin  38  is also adapted for insertion into the pin aperture  72  for either fixed or rotational engagement thereto. 
     In at least one embodiment, a detail front view, and detail end view, of the positioning bracket  48  is depicted in  FIGS. 6 and 6A . The positioning bracket  48  may be formed of a flat top surface  66 , a sidewall  80 , and a base wall  82 , which in combination are generally U-shaped. The bracket bridge  52  preferably extends from the interior surface of the top wall  66  toward the back wall  82 . The bracket bridge  52  may also be engaged to the exterior edge of the base wall  82  extending outwardly therefrom. A lower bridge extension  92  is generally defined as the section of the bridge bracket  52  extending between the base wall  82  and the leading crown  94 . The bridge bracket  52  may include wing support sections  96  which transition into a positioning ledge  78 . The transition between the leading crown areas  94  and the positioning ledge  78  along the wing support sections  96  may be substantially arcuate. 
     In at least one embodiment as depicted in  FIGS. 6 and 6A , the position relationship with a slide rod  20 , keeper plate  44  and keeper  46  within the slide channel  64  and keeper channel  74  is shown in detail. 
     In at least one embodiment, the engagement of the positioning bracket  48  to the roller bracket  34  is shown in  FIG. 7 . As depicted in  FIG. 7 , the door  21  is disposed in the latching position relative to the doorframe channel  24 . As depicted in  FIG. 7 , the swing handle  12  has been manipulated to dispose the keeper  46  rearwardly with respect to the first and second rollers  40 ,  42  to latch the positioning bracket  48  relative to the roller bracket  34  to securely close and latch a door. 
     During use, one or a plurality of control mechanisms for door latch  10  may be disposed above a swing handle  12 , and one or the plurality of control mechanisms for door latch  10  may be disposed below a swing handle  12  to securely latch a door  21  within a doorframe channel  34 . 
     The number of control mechanisms for door latch  10  utilized will be dependent upon the dimensions for the door and the security desired by an individual. 
     In one alternative embodiment as depicted in  FIG. 8 , the roller bracket  34  has been replaced by a latching bracket  98 . The latching bracket  98  includes mounting areas  68  and affixation apertures  70 . Latching bracket  98  is adapted for affixation to the back wall  28  of the door frame channel  24 , in a manner substantially identical to the roller bracket  34  as earlier described. The latching bracket  98  is substantially rectangular and includes latching member  90 , extension  100 , and mounting platform  102 . The dimensions for the latching bracket  98 , extension  100 , and mounting platform  102  may vary provided that the dimensions selected are sufficient for operative engagement of a keeper  46  rearwardly of the latching platform  102  during use of the control mechanism for door latch  10 . 
     In one embodiment as depicted in  FIG. 8 , the slide rod  20  having groups of positioning slots  30  is substantially identical to the embodiments as earlier described. The keeper plate  44  and keeper  46  preferably include tangs  84  as earlier described for adjustable positioning relative to, and engagement with the slide rod  20 . 
     In one embodiment as depicted in  FIG. 8 , the positioning bracket  48  includes a top wall  104  having a central punch out slot  106  defining a substantially perpendicular positioning frame  108 . The punch out slot  106  preferably defines mounting areas  58  which may include apertures  60 . The positioning bracket  48  as depicted in  FIG. 8  is engaged to the door  21  as separated from door edge  32  in a manner as earlier described. 
     In one embodiment as depicted in  FIG. 8 , positioning bracket  48  includes side wall  80  and base wall  82 . The area between the interior of the side wall  80 , above the base wall  82 , interior of the positioning frame  108  and below or interior to the top wall  104 , defines the slide channel  64  as earlier described. As depicted in  FIG. 8 , the area below the positioning frame  108  and above the base wall  82  defines the keeper channel  74 . The positioning frame  108  preferably includes a shelf  110  (Shown in Phantom) which may assist in the positioning of the keeper  46  within the keeper channel  74 . The keeper channel  74  may be defined as the area below the positioning frame  108  and shelf  110  and above the base wall  82 . 
     In some embodiments, the latching member  90  may be configured as a pin, bar, ledge, tab, roller, and/or any other device for engagement to the keeper  46 . The roller slot  50  and/or the central punch out slot  106  may be of any dimension and/or shape as depended upon the configuration for the latching member  90  as selected by an individual. 
     In some embodiments, the latching member  90  may be the shape of square, oval, rectangular, pin, bar, ledge, and/or may include a roller to facilitate engagement to a keeper  46 . The extension  100  may be of any dimension as desired for separation of the mounting platform  102  from the back wall  28  for rearward positioning of the keeper  46 . 
     In some embodiments, the positioning bracket  48  and roller bracket  34 , or the positioning bracket  48  and latching bracket  98 , are located at substantially identical, vertical positions along plane A with respect to the door  21  and door frame channel  24 . The substantial vertical alignment between the positioning bracket  48  and the roller bracket  34 , or latching bracket  98 , minimizes the flex of a slide rod  20  and door  21  during use of the door latch  10  and the manipulation of the swing handle  12 . The latching of a door  21  through the use of the control mechanism  10  relieves the slide rod  20  from any load, which in turn eliminates flex. 
     In some embodiments, the door  21  is aligned with plane A, and the door  21  is swung about a hinge (not shown) in a normal or perpendicular arc relative to plane A. The engagement and alignment between a positioning bracket  48  and the roller bracket  34 , or latching bracket  98 , occurs prior to the initiation of any compression forced being applied to the slide rod  20  through the swing handle  12 . The engagement and alignment between the positioning bracket  48  and the roller bracket  34 , or latching bracket  98 , permits the door  21  to engage the door frame channel  24 , which in some embodiments may include a gasket, without any side load on the slide rod  20 . This configuration for the latch mechanism  10  facilitates and reduces the wear on any gasket, hinges, slide rod  20 , door  21 , and/or slide frame channel  24 . The engagement and alignment of the positioning bracket  48  with the roller bracket  34 , or latching bracket  98 , enables an operator to manipulate the swing handle  12  with less force, which reduces risk of mechanical failure. The above described alignment of the positioning bracket  48  and roller bracket  34 , or latching bracket  98 , also reduces the application of twisting force on the slide rod  20 , and latching system, as well as the hinge side of the door  21 . 
     In some embodiments, the downward movement of the slide rod  20  occurs as a result of gravity and/or as a result of a combination of gravity and manipulation of a swing handle  12 . The control mechanism for door latch  10  in at least one embodiment is designed to utilize gravity in the event of system failure to facilitate the positioning of the keeper  46  rearwardly with respect to the roller mount  36 , or a latching member  90 , thereby facilitating the latching of a door  21 . 
     In some embodiments, groups of positioning slots  30  may be regularly spaced along the slide rod  20 . The groups of positioning slots  30  may be spaced at regular 100 mm intervals to facilitate engagement, and adjustable positioning of, a keeper plate  44 . 
     The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. 
     Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim  1  should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below (e.g. claim  3  may be taken as alternatively dependent from claim  2 ; claim  4  may be taken as alternatively dependent on claim  2 , or on claim  3 ; claim  6  may be taken as alternatively dependent from claim  5 ; etc.). 
     This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.