Patent Publication Number: US-2020291685-A1

Title: Electromechanical lock

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 15/548,347 entitled “Mechanical Override of an Electronic Lock”, filed Aug. 2, 2017, which is a national stage of PCT Application No. PCT/US2016/016123 entitled “Mechanical Override of an Electronic Lock”, filed Feb. 2, 2016, which claims priority to U.S. Provisional Patent Application No. 62/110,789, entitled “Mechanical Override of an Electronic Lock”, filed Feb. 2, 2015. The contents of all of the above are hereby incorporated in their entirety by reference for all purposes. 
    
    
     FIELD OF THE DISCLOSURE 
     The present invention relates to electromechanical locks and blocking mechanisms therefore. More particularly, it relates to manual overrides of the blocking mechanism. 
     BACKGROUND OF THE INVENTION 
     Federal Specification FF-L-2890B governs lock extensions and categorizes them as follows: pedestrian door preassembled locks (PDPL), pedestrian door lock assembly panic (PDLAP), and auxiliary deadbolts (ADB) for use with changeable combination locks and strikes. For each of these categories of extension, the specification defines types with key access control and types with keyless access control. Additionally, these extensions should be right and left hand interchangeable. 
     This invention was pursued to meet both the keyed and electronic access capabilities required per FF-26890B and be suitable for either right or left hand mounting. A single, reversible device with both access capabilities helps to optimize system design by minimizing components and packaging. The present invention can also be used in other high security lock applications where redundant access capabilities are desired. 
     SUMMARY OF THE INVENTION 
     An electromechanical lock according to the present invention includes a lock extension and a blocking module having an interior region. A pivot bolt is mounted in the interior region for rotation about a rotation axis between a nominal position and an unsecured position. First and second blockers are also disposed in the interior for movement between their respective nominal positions and an unblocking position. The lock further includes an override disposed in the interior region for movement between a nominal position and an override position. The lock is in a secured condition when the first and second blockers and the override are in their respective nominal positions and an unsecured condition when the second blocker is in its unblocking position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an exemplary blocking module in position to block a lock extension. 
         FIG. 2  is an exploded view of the blocking module of  FIG. 1 . 
         FIGS. 3A-3C  illustrate the blocking module and extension, partially cut away, in a nominal, or blocking, condition. 
         FIGS. 4A-4C  illustrate the blocking module and extension, partially cut away, in an unblocking condition. 
         FIG. 5  illustrates the blocking module and extension, partially cut away, in manual override condition. 
         FIGS. 6A-6D  illustrate component positions during retraction of the pivot bolt. 
         FIGS. 7A-7C  illustrate the manual override. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     As illustrated in  FIG. 1 , a blocking module  10  is disposed adjacent a lock extension  12 . The blocking module  10  includes a pivot bolt  14  that extends into the housing of the lock extension  12  to maintain the lock in a secured condition. The blocking module  10  and lock extension  12  would typically form an electromechanical safe lock and be housed in a metal (typically zinc alloy), rectangular case and enclosed by a stainless steel plate cover screwed to the case (not shown). 
     As illustrated in  FIGS. 2-5 , the blocking module  10  can include a housing  16  and cover  18  defining an interior region. The pivot bolt  14 , a sliding blocker  24  and spin blocker  26  driven by motor  28  are mounted in the interior region. In addition, a manual override  32 , including a drive gear  34 , an idler gear  36 , and drive pin gear  38 , is positioned to drive a plunger  40 . The drive gear includes a key-receiving slot  42  disposed along its rotational axis. 
     The pivot bolt  14  includes an integral spindle  22  that nests inside holes in the case and cover and is constrained to rotation about the spindle axis. The sliding blocker  24  is disposed in a channel  25  in the floor of the housing  16  and is constrained to move linearly in the channel  25 . In preferred embodiments, the pivot bolt  14  is biased to a lock secured condition by a torsion spring  44 . The sliding blocker  24  is biased by a compression spring  46  to block the pivot bolt  14  from pivoting to a lock unsecured condition. The spin blocker  26  is biased by a torsion spring  48  to prevent the sliding blocker  24  from releasing the pivot bolt  14 . 
     The spin blocker  26  has a circular wedge  52  extending from its center as well as a lever  54  that extends in an opposing direction. The spin blocker&#39;s central, cylindrical body is pressed onto an electric motor shaft and the assembly is then placed in a recess in the housing  16  with the wedge  52  positioned toward the sliding blocker  24 . The torsion spring  48  is applied to the spin blocker  26  to resist counter clockwise rotation as viewed from the output shaft side of the motor  28 . 
     The spin blocker  26  lever extends away from the pivot bolt  14  and makes contact with a plunger  40 . The plunger  40  has feet  56  that slide within grooves  58  in the housing  16 . The plunger  40  includes a slot  60  in which the drive pin  62  of the drive pin gear  38  is inserted. The pin  62  is offset from the rotational axis of the drive pin gear  38  and travels an orbital path about this axis when the drive pin gear  38  rotates. This orbital motion of the pin  62  interacting with the slot  60  induces translation of the plunger  40  within the housing  16 . 
     When secured, as illustrated in  FIG. 3 , the pivot bolt  14  is extended, the sliding blocker  24  contacts the pivot bolt  14 , and the spin blocker wedge  52  is in the path of the sliding blocker  24  to prevent it from sliding. Force on the pivot bolt  14  closes any gaps between the pivot bolt  14 , sliding blocker  24 , spin blocker  26  and pushes the spin blocker wedge  52  against the floor of the housing  16 , thus resisting further movement of the pivot bolt  14 . 
     To allow the pivot bolt  14  to retract into the blocking module  10 , the spin blocker  26  must be rotated such that the spin blocker wedge  52  is moved out of the path of the sliding blocker  24  as illustrated in  FIGS. 4-7 . This movement can be achieved by two methods. In keyless access control, an electrical current is supplied to the motor  28 , causing the spin blocker  26  to rotate and clear the path for the sliding blocker  24 . Rotation of the spin blocker  26  is limited to −90° by lock structure. When motor current is stopped and the pivot bolt  14  returns to its extended position, the sliding blocker  24  and spin blocker  26  are returned to secured position by springs  46  and  48 , respectively. 
       FIGS. 6A-6D  illustrate the movement of the pivot bolt  14  and slide blocker  24  during retraction of pivot bolt  14  that results in the unsecured condition illustrated in  FIG. 5 . Initially, an electrical current has been applied to the motor  28  to rotate the spin blocker  26  counterclockwise to the position best seen in  FIG. 6B . In  FIG. 6  A, an external force F is applied to the pivot bolt  14 , urging it to rotate in a clockwise direction. As it rotates, it pushes the slide blocker  24  in the direction of arrow  64 . The slide blocker  24  moves to the left, as seen in  FIG. 6B , into the space previously occupied by the spin blocker  26 . In  FIG. 6C , the pivot bolt  14  is fully retracted and held by an external force and the sliding blocker  24  is prevented from returning to its nominal position. In  FIG. 6D , the sliding blocker  24  is preventing the spin blocker  26  from returning to its nominal position. 
     For keyed access control, illustrated in  FIGS. 7A-7C , the user inserts a key into a lock cylinder (not shown) in the door and turns the key −90° in either direction. A flat spindle extending from the back of the lock cylinder is disposed in the drive gear slot  42 , thereby transferring the rotation of the user&#39;s key to rotation of the drive gear  34 . The drive gear  34  transfers the rotary motion of the key, via the idler gear  36 , to the drive pin gear  38 . As noted above, the pin  62  on the drive pin gear  38  is disposed in the slot  60  formed in the plunger  40 . As the drive pin  62  bears on the plunger slot  60 , the plunger  40  translates toward the spin blocker  26 , thereby pushing the lever  54  and lifting the spin blocker  26  out of the path of the sliding blocker  24 . Thereafter, rotation of the pivot bolt  14  forces the slide blocker  24  into the space previously occupied by the spin blocker  26 . 
     To secure the lock, the user must rotate the key back to home position were the key can be removed. All lock internal components will spring back to their respective nominal positions under the biasing forces of the torsion springs  44  and  48  and the compression spring  46 . The plunger returns to its nominal position by the pin  62  acting on the slot  60  as the drive pin gear  38  rotates in response to the rotation of the key. 
     For either type of access control employed, movement of the pivot bolt is due to external forces applied by other components in the lock extension. Similarly, these same components must move back to their original position to allow the pivot bolt to rotate back to secured position. A micro switch within the lock assembly senses pivot bolt position and can provide this signal to the lock extension controls. 
     Advantageously, the present invention gives the lock two methods of access control and allows the end user to employ either or both in a given installation. In addition, the lock can be reversed to accommodate right or left handed door configurations. Key rotation in either direction results in the same necessary motion required for access. Further, packaging of lock internal components is efficient yet compatible with the industry standard high security lock foot print (“magic module”) and smaller foot prints. 
     The above-described embodiment is not to be considered as limiting the breadth of the present invention. Modifications and other alternative constructions will be apparent that are within the spirit and scope of the invention as defined in the appended claims. For example, one variation might include the use of cams and levers in lieu of the gear train described above for the mechanical override.