Abstract:
An electronic lock employs an electronic latch for operating the lock bolt. The lock utilizes a flexible member linked between a portion of the lock bolt and a solenoid device. Upon retraction of a solenoid driver, the flexible member pulls the deadlocking lever for latch retraction. When the flexible member is released by the driver, the bolt can extend for a subsequent opening.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention is directed to an improved electronic lock, and in particular to an electronic lock employing an electrically actuated driver and a flexible member linked to a portion of a latch assembly of the lock bolt for latch retraction.  
         BACKGROUND ART  
         [0002]    In the prior art, electronic locks are known as disclosed in U.S. Pat. No. 5,636,880 to Miller et al., herein incorporated in its entirety by reference. This patent discloses an electronic lock using a ring and electrically actuated driver for lock operation. The lock of this patent is advantageous in that it can be used as a retrofit for existing locks or be manufactured as a new lock. One disadvantage of the lock of the Miller et al. patent is that the ring requires close manufacturing tolerances, thus increasing lock manufacturing cost. In addition, the number of cycles of lock operation with the ring can be less than desired for some applications. Accordingly, a need has developed to provide an improved electronic lock overcoming the disadvantages noted above.  
           [0003]    The present invention solves this need by providing an improved electronic lock that overcomes the deficiencies present in prior art locks. In particular, the inventive lock employs a flexible member that allows for easy and efficient lock bolt retraction, thus eliminating the high tolerance machining required in prior art locks.  
         SUMMARY OF THE INVENTION  
         [0004]    Accordingly, it is a first object of the present invention to provide an improved electronic lock.  
           [0005]    Another object of the present invention is an electronic lock having high durability.  
           [0006]    A further object of the present invention is a method of retracting a lock bolt using the inventive lock.  
           [0007]    Other objects and advantages will be apparent as a description of the invention proceeds.  
           [0008]    In satisfaction of the foregoing objects, the electronic lock of the present invention comprises a lock having a retractable latch assembly, an electrically actuated driver, and at least one flexible member linked between a portion of the electrically actuated driver and a portion of the retractable latch assembly. The flexible member has a length such that retraction of a portion of the electrically actuated driver retracts a retractable latch of the latch assembly of the lock for lock opening.  
           [0009]    The lock can be a narrow stile type lock and the flexible member can be a chain, metal braided cable, ribbon, blended Kevlar/fiberglass ribbon, a coated metal cable, a solid wire or the like.  
           [0010]    The retractable latch can include a pivot arm with one end of the flexible member secured to the pivot arm for lock operation. The pivot arm can have a bore therethrough to facilitate attachment with the flexible member. More than one flexible member can be employed and a solenoid can be used as the actuated driver. The lock can also employ a guided portion for the flexible member&#39;s travel during driver movement, with or without a radius to further facilitate movement of the cable.  
           [0011]    The invention also includes a method of retracting a latch of a lock by actuating the electrically actuated driver to pull the flexible member. Pulling on the flexible member causes a portion of the latch assembly to retract so that the lock is in an open position for ingress or egress to an area. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    [0012]FIG. 1 is a side view of one embodiment of the inventive lock;  
         [0013]    [0013]FIG. 2(A) shows a portion of the lock mechanism of the FIG. 1 embodiment;  
         [0014]    [0014]FIG. 2(B) shows a side view of the deadlocking lever removed from the lock;  
         [0015]    [0015]FIG. 2(C) shows a front view of the deadlocking lever of FIG. 2(B);  
         [0016]    [0016]FIG. 3 shows a perspective view of the lock of FIG. 1;  
         [0017]    [0017]FIG. 4(A) shows a contour plate for the inventive lock; and  
         [0018]    [0018]FIG. 4(B) shows another embodiment of the contour plate of FIG. 4( a ). 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    The improved electronic latch is a device used to allow access through an entryway by means of electrical activation.  
         [0020]    When energized, a solenoid, motor, or other electromechanical device retracts the latchbolt by means of an attached cable, tether, microchain or other flexible attachment.  
         [0021]    Referring to FIG. 1, the solenoid ( 1 ) retracts a plunger ( 2 ) to which is attached a cable ( 3 ) or other flexible member by means of a pin ( 4 ). The cable is attached to the deadlocking lever ( 5 ) that in turn pulls the latchbolt ( 6 ) into the body of the lock. When the solenoid is de-energized, a spring ( 7 ) pushes the latchbolt back into the extended position.  
         [0022]    One key element of this design is the attachment of the cable to the deadlocking lever ( 5 ). Referring to FIG. 2, the deadlocking lever is attached to the latchbolt by a pivot ( 8 ) and is guided by slot ( 9 ) cut into the chassis ( 10 ) into which rests a pin extension ( 11 ) of the deadlocking lever ( 5 ). When the deadlocking tab ( 12 ) is pushed in, the pin extension ( 11 ) is rotated into the upper portion of the slot which prevents the latchbolt from being pushed inward. The cable ( 3 ) must first pull the pin down and out of this portion of the slot, and then continue to pull the deadlocking lever ( 5 ) along the length of the slot. The cable would be typically attached to the deadlocking lever ( 5 ) by looping and insertion through a hole ( 13 ).  
         [0023]    [0023]FIG. 3 shows a perspective view of an exemplary lock using the flexible member. In FIG. 3, the lock chassis is designated by the reference numeral  10  and depicts the solenoid  1  as a 1″×2″ pull type solenoid. Also depicted is the slot  9  which acts as a guide for the pin extension  11  of the deadlocking lever  5 . The slots  21  in the chassis  10  act as guides for travel of the deadbolt/latch when moving between the extended and retracted positions.  
         [0024]    Downward linear motion (or even rotary motion if size and force determine) retracts the plunger. The deadbolt  6  is attached to the solenoid  1  via a yoke  23  and the cable or tether  3 . The connection between the solenoid and bolt can be made of Teflon, Kevlar, steel band, cable, or chain. Attachment to the bolt can be a yoke tapped into the bolt beneath the hook  5 . A guide for the tether or cable  3  can be a contour plate  25  which fits within the chassis  10 . The contour plate can have a smooth or polished surface  27  and can mount to the chassis in any way. The surface  27  acts as a low friction guide for the cable during its movement.  
         [0025]    [0025]FIGS. 4A and 4B show a contour plate and an improved contour plate, respectively, as described above. Referring to FIG. 4A, the contour plate  25 ′ can have protrusions  29  to interface with slots  21  and protrusion  31  to interface with the chassis  10 . A modified contour  25 ″ plate is shown in FIG. 4B whereby the surface  27 ″ has a slot  33  which better guides the cable during its travel. The plate  25 ″ can also employ a radiused edge  35  to ease sliding action of the cable  3 .  
         [0026]    The advantages of invention are:  
         [0027]    1) Continuous linear motion. The use of a flexible cable eliminates the need for a mechanism to change the direction of force.  
         [0028]    2) Minimal parts are needed so that there are fewer points at which mechanical wear can occur.  
         [0029]    3) The cable &amp; solenoid assembly configuration is not dependent upon whether the lock is used on a right hand or left-hand door.  
         [0030]    The use of a thin cable allows for a very narrow profile which makes the lock easy to install in aluminum frame doors.  
         [0031]    Although a solenoid is depicted, other known drivers can be used. The driver can be mounted on the lock or adjacent thereto. The flexible member can be a single member or plural members and can be any type of a wire, cable, ribbon, chain, or the like that will have sufficient strength to pull the latch repeatedly without premature failure. Although narrow stile locks are preferred, the driver and flexible member assembly can be employed in any lock where latch retraction is desired by means other than a key cylinder or the like.  
         [0032]    As such, an invention has been disclosed in terms of preferred embodiments thereof which fulfills each and every one of the objects of the present invention as set forth above and provides a new and improved electronic lock.  
         [0033]    Of course, various changes, modifications and alterations from the teachings of the present invention may be contemplated by those skilled in the art without departing from the intended spirit and scope thereof. It is intended that the present invention only be limited by the terms of the appended claims.