Abstract:
A sliding closure (door or window) lock has a rectangular tubular enclosure which has a plunger mounted on am interior camshaft. Rotation of the camshaft by a handle or lever moves the plunger between an extended position, where its serrated outer end frictionally engages an interior surface of the channel for the closure, and a retracted position without frictional engagement. The enclosure has an adjacent apertured flange to secure it to an inner surface of the closure. The device may be made of two plates in which case one plate forms two walls of the enclosure and the flange, and the other the other two walls and a thickness of the flange. A stub flange also with apertures on remote corner of the enclosure allows the plates to be fastened at the other side of the enclosure.

Description:
[0001]    This invention relates to locks for sliding closures doors, especially glass doors, or windows. Horizontally sliding glass doors or windows are common, and they are a common point of entry for breakins, typically by forcing the sliding portion of the door or window to move in its channel. If glass in the door or window is smashed no lock will prevent entry. Typically current sliding windows and doors are secured by a piece of material, typically metal, plastic or wood, in the channel preventing movement of the sliding portion.  
         BACKGROUND  
         [0002]    Sliding doors (patio doors) and windows, have a need for a workable locking device. By nature of their construction the locks used on most sliding doors, etc., are easy targets for break and enter. The sliding door consists of a frame (upper guide, lower guide and sides), a fixed panel or window and a sliding door. To install the sliding door into the frame the upper guide must have room to lift the door into the upper guide, clearing the lower guide, then dropping the door down into/onto the lower guide. The regular lock for sliding doors is generally a downward hook, hooking onto a small bar attached to the side frame. To enter a room/home via the locked sliding door from outside, the break and enter expert needs only to lift the door with a pry bar, unhooking the lock, push the door to the side and to the inside of the room, gaining entry to the room/home. The need is for a locking device that prevents the lifting and side movement of the sliding door.  
           [0003]    The invention comprises a extendible plunger mounted on a frame, attachable to a sliding door or similar closure, which when extended engages the channel in which the closure slides, conveniently a flange on, or integral with, the frame allows attachment to the closure.  
         PRIOR ART  
         [0004]    Applicant is not aware of any closely related art.  
           [0005]    It is a principal object of the invention to provide an extendible plunger mounted in a frame attachable to a sliding door or window, so that the plunger when extended engages the channel in which the door or window slides. It is a subsidiary object of the invention to mount the plunger on a cam, by rotation of which the plunger is extended and retracted. It is a further subsidiary object of the invention to provide a serrated edge on the plunger to engage the channel. It is a further subsidiary object to provide a serrated edge slanted into the channel away from the sliding door or window. It is a further subsidiary object that the plunger is substantially parallel to the sliding door or window within the frame and angled away from the sliding door outside the frame. It is a further subsidiary object that a flange for attachment to the sliding door or window be attached to the frame. It is a further subsidiary object that a flange for attachment to the sliding door or window be integral with the frame.  
         DESCRIPTION OF THE INVENTION  
         [0006]    The invention in one broad aspect is directed to a lock for a closure sliding in channels. It has an attachment plate member to attach to an edge of the closure, and plunger means to engage one channel. The plunger means is extendible between a first retracted position where the plunger means does not engage the channel, and a second extended position where the plunger means engages the channel. Preferably the plunger means has a planar serrated end surface to engage the channel in second extended position. The serrated end surface when engaging is preferably coincident with the channel for maximum frictional engagement. Preferably the plunger means in extended position pivots about a pivot means operatively associated with the plate member in a plane substantially at right angles to the plate member. Preferably the pivot means is mounted in wall members extending outward of the plate member, in which it may be conveniently journalled. Preferably there is a stop member operatively associated with and spaced apart from the plate member which limits movement of the plunger means outward of the plate member. Preferably the stop member extends between the wall members. Most preferably the plunger means has a planar serrated end to engage the channel in second extended position, and the planar serrated end surface contacts the channel, when the plunger means contacts the stop member. The position of the stop member is preferably placed so that the serrated end surface when engaging is preferably coincident with the channel for maximum frictional engagement. Alternatively the serrated end surface may be angled into the channel away from the closure, again for frictional engagement. Preferably the plunger means pivots about a primary pivot means operatively associated with the plate member between first retracted and second extended position in a plane substantially at right angles to the plate member. Preferably in extended position the plunger means pivots about a secondary pivot means operatively associated with the primary pivot means.  
           [0007]    Preferably the primary pivot means is mounted in wall members extending outward of the plate member and the secondary pivot means is mounted on the primary pivot means. Preferably there is a stop member extending between the wall members which limits movement of the plunger means outward of the plate member. Conveniently the primary pivot means is a spindle or shaft extending between the wall members, and the secondary pivot means is a cam mounted upon the shaft or spindle. The invention is not restricted to such pivot means, as those skilled in the art are aware numerous alternative arrangements are available. Preferably the plunger means has a planar serrated end to engage the channel in second extended position, and the planar serrated end surface contacts the channel, when the plunger means contacts the stop member.  
           [0008]    In another broad aspect the invention is directed to a lock for closures sliding in channels. The lock comprises a rectangular enclosure having first and second opposed ends, first, second, third and fourth wall member. The first and third wall members are opposed, parallel, and spaced apart. The second and fourth wall members are also opposed, parallel and spaced apart, at right angles to and connecting the first and third wall members. There is a flange member operatively associated with and at right angles to the first wall member and projecting away from the rectangular enclosure. This flange member can abut and be fastened to an inner surface of the closure, and the first wall member can abut an edge of the closure. A camshaft extends between the second and fourth wall members, parallel to the first and third wall members, with cylindrical ends journalled into the second wall member and the fourth wall member. Its cam is journalled into a first end of a plunger means, which has a second serrated end projecting beyond the first end of the rectangular enclosure. When rotated the camshaft moves the second serrated end of the plunger means between a first retracted position beyond the first end of the enclosure and a second extended position further beyond the first end of the enclosure. The serrated end of the plunger means is generally planar and parallel to the channel, when touching the third wall member. In use the flange is affixed to an inner surface of the closure, and the first wall abuts an edge of the closure, and the plunger means extends into a channel in which the closure slides. When the plunger means is in first retracted position the serrated second end does not engage a surface of the channel, when in second extended position the serrated second end frictionally engages a surface of the channel, and movement of the closure in the direction of the lock, rotates the second serrated end of the plunger means into tighter frictional engagement.  
           [0009]    The plunger means preferably has a first portion within the rectangular enclosure when retracted and a second portion outside the rectangular enclosure when retracted, the second portion being angled away from the closure. This gives greater moment to the frictional force created by shoving the closure toward the lock.  
           [0010]    Instead of the serrated edge being parallel to the channel it may be angled toward it outward of the closure. Again this creates greater frictional force when shoving the closure toward the lock.  
           [0011]    Preferably the cylindrical ends of the cam shaft are journalled into bearing blocks in the second and fourth wall members. More preferably the bearing blocks are exterior of the wall members and welded thereto. Conveniently the camshaft end nearest the flange has a handle outward of the flange to rotate the camshaft. The lock may comprise two abutting plates. A first rear plate has a first flange to abut the closure inner surface. The first wall member is joined on one side at right angles to the first flange. The fourth wall member is joined at the other side of the first wall member at right angles to the first wall member and extending beyond the rectangular enclosure. A second front plate has a second flange member to fit over the first flange member. There is a fifth wall member joined at right angles on one side to the second flange member to fit over a portion of the first wall member. The second wall member is joined at one side at right angles to the other side of the fifth wall member. The third wall member is joined at right angles at one side to the other side of the second wall member. There is a third flange joined at right angles to the other side of the third wall member to fit over a portion of the fourth wall member. The first and second flange members have a plurality of first apertures registrable with each other to allow fasteners to pass through the first apertures and secure the flanges together to a closure surface. The third flange and the fourth wall member having a plurality of second apertures registrable with each other to allow fasteners to pass through the second apertures and secure the third flange to the fourth wall member.  
           [0012]    The invention when engaged prevents the lifting and side movement of the door. When activated the plunger means of the lock pushes against the upper guide/frame for the door putting downward pressure on the door. This downward pressure on the door top prevents upward movement of the door. The plunger means being angled slightly away from the door restricts the side movement of the door. The more side pressure applied to the door the more the plunger means digs into the upper guide/frame preventing the door being pushed open. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 shows a front elevational view of an embodiment of the invention.  
         [0014]    [0014]FIG. 2 shows a rear elevational view of the embodiment of FIG. 1.  
         [0015]    [0015]FIG. 3 shows a top plan view of the embodiment of FIG. 1.  
         [0016]    [0016]FIG. 4 shows a front elevational view of the embodiment of FIG. 1 with the front plate removed.  
         [0017]    [0017]FIG. 5 shows a cam shaft of the invention.  
         [0018]    [0018]FIG. 6 shows a rear elevational view of a casing and plunger of another embodiment of the invention.  
         [0019]    [0019]FIG. 7 shows a plunger of the embodiment of FIG. 6.  
         [0020]    [0020]FIG. 8 shows a top plan view of the casing of FIG. 6 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    The invention is illustrated but not restricted by reference to the preferred embodiments. Numeral  10  generally indicates a lock of the invention mounted on moving closure  12  (door, door frame or window frame) sliding in channel  14 . Lock  10  has front plate  16  with central channel portion  18  and side flanges  20  and  22 . Flange  20  has four screw holes  24 , two of are occupied by attachment screws  26 , attaching it to closure  12 . Flange  22  has two screw holes  28  both occupied by bolts  30 . Channel portion  18  has front bearing block  32  spot welded to channel portion  18  by welds  34 , shaft  36  passes through front bearing block  32  and is rotatable by handle  38 . Plunger  40  has serrated top  42  which engages top  44  of channel  14 . Lock  10  has rear plate  46  of which rear flange  48  which is secured to front flange  42  by nuts  56  engaging bolts  30 . Rear bearing block  52  is spot welded to flange  48  by welds  54 , and engages shaft  36 . Rear plate front flange  50  contacts front flange  16  and is secured to it by screws  26  passing through screw holes  58 . As shown in FIG. 3, front plate offsets  60  and  62  together with rear plate offset  64  and flange  46  and front central portion  18  forms tube or channel  66 , in which plunger  40  is mounted on shaft  36 . As shown in FIG. 4, shaft  36  has cam  68  journalled into cylindrical aperture  70  in plunger  40 . On rotation of cam  68  plunger  40  moves up and down, upward motion forces top serrated surface  42  into tight frictional engagement with the top surface of channel  44 . Shaft  36  has square front portion  72  protruding forward of front bearing block  32  and cylindrical front portion  74  journalled into front bearing block  32 , it also has cylindrical rear portion  76 , which is journalled into rear bearing block  52 .  
         [0022]    Lock  10  is fixed on the side of closure  12 , when the closure slides horizontally, so that when plunger  40  is lowest it clears channel top  44 , by a suitable clearance as known to those skilled in the art, typically about ⅛ inch. When the handle is rotated moving plunger  40  upward, its serrated top  42  frictionally engages channel top  44 . Attempts to move closure  12  toward plunger  40  rotates plunger  40  upward forcing serrated top  42  into channel top  44 , increasing frictional resistance to motion. Front plate offset  60  prevents plunger  40  rotating downward and disengaging channel top  44 .  
         [0023]    In FIGS.  6  to  8  is shown a variant embodiment of lock  10 . Rear plate  146  has rear flange  148  securable through screw holes  128  to opposing front plate flange  122 , similarly front flange  150  of rear plate  146  is securable to opposing front plate flange  120  through screw holes  124 . Circular hole  172 , about {fraction (5/16)} inch diameter, accommodates shaft  174  as above. Plates  116  and  146  are about 4½ inches high, and are about {fraction (1/16)} inch thick. Rear portion of rear plate  146 , including flange  148 , extends about 1¾ inch (external), offset  164  about {fraction (1/16)} inch (external), rear flange  150  about ⅞ inch. Rear flange of front plate  122  extends about ⅜ inch, rear offset  160  about {fraction (1/16)} inch, central channel portion  118  about 1{fraction (1/16)} inch, front offset  162  about ⅛ inch, front flange  120  about  1  inch. As a result channel  66  is about {fraction (1/16)} inch by about 1{fraction (1/16)} inch. Plunger  140  is about ⅜ inch thick and ⅞ inch wide. It has angled end  144  with serrated top  142  to engage the inner (lower) surface of a sliding door channel. It also has hole  170 , about ⅝ inch diameter to receive cam  6 , concentric with round bottom  174 , about ⅞ inch diameter (about {fraction (1/16)} inch radius). Outer edge  176  extends about 2⅜ inch above center of hole  170  to edge  180  angled outward at 22°. Inner edge  178  extends about 2½ inch above center of hole  170 , to edge  182  similarly angled at 22°. The meeting point of serrated top  142  and edge  182  is about 3{fraction (5/16)} inch from center of hole  170 . Edge  142  is angled upward and outward at 93° from (the projection) of edges  176  and  178 .  
         [0024]    Plunger  140  has less horizontal play than plunger  40 , in rest position being essentially vertical or parallel to the edge of the door. When handle  38  and cam  68  rotate it rises to engage an upper door channel. It cannot be rotated down or away from the door, while rotating upward jams it harder in the channel.  
         [0025]    Lock  10  could also be attached to the bottom or top of a sash window to engage lockingly a side channel or on the top of a vertically sliding door or an overhead door similarly to engage lockingly a side channel. It could further be used on the top of a portcullis to engage lockingly a side channel.  
         [0026]    Although lock  10  could be made with an integral frame or by for example extrusion or similar processes of manufacture, from for example aluminum metal, or similar materials, it is preferred that it be made in two parts, which allows the lock to be taken apart and put together. By reversing the location of the protruding plunger end, lock  10  may be made left-handed or right handed as required, and thus fitted on either side of a sliding door or window.  
         [0027]    As those skilled in the art would realize these preferred described details and materials and components can be subjected to substantial variation, modification, change, alteration, and substitution without affecting or modifying the function of the described embodiments.  
         [0028]    Although embodiments of the invention have been described above, it is not limited thereto, and it will be apparent to persons skilled in the art that numerous modifications and variations form part of the present invention insofar as they do not depart from the spirit, nature and scope of the claimed and described invention.