Patent Publication Number: US-8523250-B2

Title: Top-and-bottom latch structure for lock

Description:
BACKGROUND OF THE INVENTION 
     (a) Technical Field of the Invention 
     The present invention relates to a top-and-bottom latch structure for a lock. More particularly, the present invention relates to a top-and-bottom latch structure, which enables a lock to have top-and-bottom latch effects, thereby improving the safety of the lock. 
     (b) Description of the Prior Art 
     Accordingly, besides a large lock tongue, triangle lock tongue, and small lock tongue, a conventional lock structure further includes a latch interlocked with the small lock tongue. When the lock is turned by a knob or a key in the normal state, the lock is in the lock-on state by the lock tongue. For the conventional lock, in addition to the lock tongue embedded in the door frame to form the closed state, the conventional lock has another auxiliary locking device. Although a top-and-bottom latch may be used together with the lock, the top-and-bottom latch cannot be interlocked with the lock, so that the installation and operation are rather complicated. In view of the above problem, the applicant has developed a lock having the top-and-bottom latch effect after making continuous research and experiments based on years of experience. 
     SUMMARY OF THE INVENTION 
     Accordingly, an objective of the present invention is to provide a top-and-bottom latch structure for a lock, which enables the lock in use to have the locking effect of the top-and-bottom latch, thereby improving the safety of the lock. 
     The top-and-bottom latch structure for a lock includes a lock formed by a casing, and a lock tongue, a lock core, a handle spindle, and other components disposed in the casing. The handle spindle is provided with a first and a second protruding rod disposed at different angles, and a first and a second braking piece is respectively disposed above and under the handle spindle, so that the two braking pieces are respectively clamped by the protruding rods. The top-and-bottom latch structure for a lock further includes: two fixing members, respectively connected to the braking pieces, and tact switches, connected to a door panel by the fixing members via connecting rods. Therefore, when the door is closed, the tact switches once touching the door frame are embedded into the door frame and the fixing members move downwards to rotate the handle spindle and lock the lock tongue. When the handle spindle is pressed down, the lock tongue is drawn back, which at the same time drives the fixing members to move upwards to make the lock tongue be disengaged from the door frame to unlock, and thus the lock has the effect of the top-and-bottom latch, thereby improving the safety of the lock. 
     According to the top-and-bottom latch structure for a lock, the first braking piece is provided with a bump connected to the fixing member. The bump has a groove, so that the first protruding rod of the handle spindle is disposed in the groove to drive the first braking piece. 
     According to the top-and-bottom latch structure for a lock, the second braking piece is provided with a plate connected to the fixing member. The plate is provided with a through hole for fixing to the casing, and one end of the plate is provided with a groove, so that the second protruding rod of the handle spindle is disposed in the groove to drive the second braking piece. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a structural view of the present invention; 
         FIG. 2  is a stereogram of a tact switch of the present invention; 
         FIG. 3  is an assembling schematic view of the present invention; 
         FIG. 4  is a schematic view illustrating locking motions of the present invention; and 
         FIG. 5  is a schematic view illustrating unlocking motions of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 ,  2 , and  3  are respectively a structural view, a stereogram of a tact switch, and an assembling schematic view of the present invention. As shown in the figures, the present invention includes a lock  100  formed by a casing  1 , and a lock tongue  11 , a lock core  12 , a handle spindle  13 , and other components disposed in the casing  1 , and further includes tact switches  2  disposed on upper and lower edges of a door panel. The handle spindle  13  is provided with a first protruding rod  131  and a second protruding rod  132  disposed at different angles, and is respectively provided with a first braking piece  14  above the handle spindle  13  and a second braking piece  15  below the handle spindle  13 , so that the first and second braking pieces  14 ,  15  are respectively clamped by the first and second protruding rods  131 ,  132 . The first and second braking pieces  14 ,  15  are respectively connected to fixing members  16 ,  17  above and below the casing  1  by connecting rods  141 ,  151 . 
     The first braking piece  14  is provided with a bump connected to the fixing member  16  via the connecting rod  141 . The bump has a groove  142 , so that the first protruding rod  131  of the handle spindle  13  is disposed in the groove  142  to drive the first braking piece  14 . 
     The second braking piece  15  is provided with a plate connected to the fixing member  17  via the connecting rod  151 . The plate is provided with a through hole  152  for fixing to the casing, and one end of the plate has a groove  153 , so that the second protruding rod  132  of the handle spindle  13  is disposed in the groove  153  to drive the second braking piece  15 . 
     The tact switch  2  is provided with a lock tongue  21  and a catching plate  22  interlocked with the lock tongue  21 , and is provided with a fixing ring  23  on the bottom thereof. 
     By the above combination of components, after the lock  100  is installed on the door panel  3 , the two fixing members  16 ,  17  are respectively connected to the first and second braking pieces  14 ,  15  via the connecting rods  141 ,  151 , and the fixing members  16 ,  17  are respectively connected to the fixing rings  23  of the tact switches  2  on the door panel  3  via connecting rods  161 ,  171 . When the door is closed, since the catching plate  22  of the tact switch  2  touches the door frame, the lock tongue  21  is embedded in the door frame, and the fixing ring  23  moves downwards, thereby making the fixing members  16 ,  17  move downwards, so that the lock core  12  rotates to lock the lock tongue  11 . When the handle spindle  13  is pressed down, the lock tongue  11  is drawn back, which at the same time drives the fixing members  16 ,  17  to move upwards to make the lock tongues  21  be disengaged from the door frame to unlock, and thus the lock has the effect of the top-and-bottom latch, thereby improving the safety of the lock. 
       FIG. 4  is a schematic view illustrating locking motions of the present invention. Referring to  FIGS. 2 and 3  together, when the door is closed, the catching plates  22  of the tact switches  2  disposed on the upper and lower edges of the door panel  3  touch the door frame, and are pressed inwards by the door frame. Accordingly, the lock tongues  21  tilt upwards to be embedded into the door frame, and the fixing rings  23  relatively move downwards to make the fixing members  16 ,  17  move downwards to drive the first and second braking pieces  14 ,  15  to rotate the lock core  12 , and further the lock tongue  11  protrudes out of the casing  1  to be locked, so that the lock has the effect of the top-and-bottom latch, thereby improving the safety of the lock. 
       FIG. 5  is a schematic view illustrating unlocking motions of the present invention. Referring to  FIGS. 2 and 3  together, when the handle spindle  13  is pressed down, the original motion of the lock  100  is making the lock tongue  11  drawn back, which at the same time drives the first and second braking pieces  14 ,  15  to further drive the fixing members  16 ,  17  move upwards, so that the lock tongues  21  of the tact switches  2  are pushed upwards due to the fixing rings  23 , which are converted into the flat state to be disengaged from the door frame to unlock. 
     While the present invention have been described with reference to certain preferred embodiments, those of skill in the art will appreciate that the above preferred embodiments are only intended to explain the present invention and does not limit the protection scope of the present invention. Various modifications, equivalent replacements, improvements and so on without departing from the spirit and scope of the invention as recited in the claims, are all included in the rights protection scope of the present invention. 
     In view of the above, in the present invention, the lock having braking pieces and fixing members is used together with the tact switches of the door panel to constitute the top-and-bottom latch structure for a lock, so that the lock in use has the locking effect of the top-and-bottom latch, thereby improving the safety of the lock. The present invention meets the practicability requirement, and is a novel invention, so is filed for granting with the patent.