Patent Publication Number: US-8534719-B2

Title: Door top latching actuation

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to controlling the locking of doors, and more particularly the unlocking of doors as at their tops. 
     There is need for compact, simple, durable efficient and secure door unlocking systems, and methods, particularly when unlocking is needed at opposite sides of doors. This is of particular need when unlocking is required as in response to turning of door handles and no door latching mechanism is to be employed or is available, at vertical edges of doors, for security reasons. 
     SUMMARY OF THE INVENTION 
     It is a major object of the invention to provide door unlocking apparatus and methods of operation, to meet the above need. Basically, the apparatus of the invention comprises door top latching apparatus, comprising in combination: 
     a) a mounting bracket configured to attach to a door top, 
     b) a latch located by the bracket to move up and down, relative to the door top, 
     c) an actuator rod extending vertically below the latch, and operatively connected to the latch whereby door handle operated vertical movement of the rod moves the latch vertically, 
     d) and a compression spring associated with the rod for urging the rod and latch upwardly into latching position, the spring accommodating downward movement of the rod and latch, to unlatch the door, 
     e) and a motion adaptor operatively connected between the rod and latch. 
     As will be seen, a door handle rotation responsive assembly is typically connected to the lower end of the rod, and characterized in that rotation of the assembly effects downward compression of the spring, the door carrying the latching assembly, spring and latch in compact integration. The door top typically has a cut-out or recess in alignment with the actuating rod, latch and spring for highly efficient handle rotation responsive operation. 
     Another object includes provision of a secondary compression spring associated with the bracket, and supporting the rod. 
     A further object includes provision of an adaptor operatively connecting the upper end of the rod to the latch, in concealed position, as in the cut-out in the door top. In this regard, a support for the secondary spring may also be located in the cut-out, in concealed condition, at the door top. 
     Another object comprises provision of an adjustable connection at the lower end of the rod, blocking rod rotation and thereby rotationally adjusts the position of the adaptor relative to the latch above the adaptor, the adaptor having threaded connection to the rod. 
     These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which: 
    
    
     
       DRAWING DESCRIPTION 
         FIG. 1  is a perspective view of the latch actuation assembly; 
         FIG. 2  is an enlarged side view of the  FIG. 1  assembly; 
         FIG. 3  is a further enlarged side view of a lower portion of the assembly; 
         FIG. 4  is a perspective view of a spindle component of the assembly, also seen in  FIG. 3 ; 
         FIG. 5  is a detailed and enlarged view of upper extent of the assembly; 
         FIG. 6  is a side elevation taken on lines  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a horizontal section taken on lines  7 - 7  of  FIG. 5 ; 
         FIG. 8  is a perspective view of components of a captivating adaptor, as seen in side view in  FIG. 5 ; 
         FIG. 9  is a view like  FIG. 2 , but with the door removed; 
         FIG. 10  is a view like  FIG. 9  but with door components in place; and 
         FIG. 11  is a perspective, exploded view of door top components. 
     
    
    
     DETAILED DESCRIPTION 
     In the drawings, showing a preferred top latch actuating device, a U-shaped mounting bracket  10  is attached to the top ledge  11  of a door  12 , recessed below the door top edge  13 . Cut-out  13   a  allows reception of the bracket U-shaped portion  10   a  below the level of ledge  11 . Ledge  11  also carries a mounting bracket  14  for a top latch  15 . Bracket  14  has a U-shaped portion  14   a  extending upwardly toward the level of edge  13 . The bracket  10  has mounting wings  10   b  extending horizontally over ledge extents  11   a ; and bracket  14  also has mounting wings  14   b  extending horizontally over door ledge extents  11   a . Fasteners  16  connect the wings  10   b  and  14   b  to such ledge extents, at opposite sides of the cut-out, whereby retractable latch  17  is centered relative to the brackets, for up-down movement.  FIG. 5  shows the latch  17  urged upwardly by a spring  18  into a recess in  19  in wall structure, above the door  12 , as for locking the door. 
     The latch structure includes a cylindrical body  29  carried by and assembled to bracket  14 , and projecting downwardly within the interior of the protective bracket  10 . A plunger  21  projects downwardly within body  29 , and protrudes at  21   a  below the bottom level of  29  to terminate at an enlarged head  21   b . Compression spring  18  extends about  21 , within  29 , and urges the latch  17  lower structure  17   d  upwardly, into the position as seen in  FIG. 5 . The plunger upper end is attached to  17   d , to move with the latch, and to displace the latch downwardly upon pulling of the plunger downwardly, acting to compress the spring  18 . Such downward displacement of the latch  17  releases it from the wall recess  19 . 
     Such downward displacement of the latch is effected by downward pulling of an elongated actuator rod  26 , which may not be in direct axial alignment with plunger  21 , for operating the latch, due for example to sideward deviation at its lower end connection to mechanism operated by door handle  30 . Also, rod weight transmission to the plunger may exert unwanted side loading tending to bind or interfere with smooth operation of the latch. This is further affected by upward force transmission by compression spring  18  exerted at the lower end of the latch. As shown, spring  18  typically extends about the plunger, to resist downward travel of the plunger, as handle  30  is rotated. 
     To overcome such difficulties, a motion adaptor is provided to be easily assembled to and between the upper end  26   a  of the rod  26  and the latch mechanism, as at the time of installation. As shown in  FIGS. 5-7 , the adaptor  35  is readily connected to the latch mechanism as by sideward connection to the lower end of the plunger  21 , as shown in  FIG. 5 . The illustrated adaptor  35  comprises a hollow body  36  upwardly threadably receiving the threaded upper end  26   a  of the rod, and downwardly receiving the plunger  21 , with the plunger head  21   b  rotatably and loosely received within the adaptor upper chamber  35   a . Note the adaptor sideward projections  37  and  38  abutting the upper surface of head  21   b . A slight radial gap is provided at  39  between the outer cylindrical surface  21   a  of the plunger, and the projections  37  and  38 , allowing limited lateral relative adjustment of the rod between the adaptor and the plunger. The upper end portion  26   a  of the rod is threaded for screw-on connection to the adaptor bottom wall  35   b  during assembly, the rod end projecting in chamber  35   c  toward the adaptor interior wall  35   a . The adaptor can be rotated on the rod threading to lengthwise adjusted position. 
     Thereafter, the plunger is fitted through adaptor open side  51 , see in  FIGS. 7 and 8 , and a cover  52  attached to the adaptor side  53  and fastened as via fasteners  54 , captivating the plunger head in position in the adaptor, as seen in  FIGS. 5 and 6 . Accordingly, the assembly of components enables self-adjustment of the elongated rod to the latch, preventing binding during use. 
       FIGS. 2 and 3  shows provision for adjusting positioning of the rod lower end, as by a tube  68  receiving, and threaded to the rod, the tube connected to a spindle  60 . The lower end of the spindle has tongue and groove connection at  65  to retainer  62 , operated up and down by the mechanism  64  in turn operated by rotation of the handle  30 . See  FIGS. 1 and 3 . The laterally linear tongue and grooves  65   a  and  65   b  prevent rotation of the spindle. The rod is threaded connection to the adaptor, whereby adaptor vertical positioning relative to the latch is easily obtained, as described. 
     Also shown in  FIG. 5  is optional use of a compression spring  70  beneath the adaptor, and biasing the adaptor upwardly, the spring located between the adaptor and a cross-piece lower portion  71  of the U-shaped bracket  10  attached to the upper edge of the door. Spring  70  is used to counter-act weight imposed by the rod, such weight depending upon encountered differences in density of the used rod material. The spring and adaptor urge the latch upwardly, toward locked position, but allow latch retraction in response to handle actuated downward pull of the rod. 
     Intermediate lateral internal wall  75  of the adaptor blocks inadvertent travel of the rods end  26   a  upwardly to jam plunger  21   b . Accordingly, compact adaptor  35  has multiple retention positioning, adjusting and aligning functions as described.