Lock

Abstract

A lock includes a housing having a plurality of apertures receiving buttons. A biasing member biases each button towards an un-pressed position. A plurality of spools includes circumferential grooves. Each circumferential groove has a notch that is angularly displaced relative to each of the other notches on that spool. A plurality of legs is in communication with one of the buttons and contacts one of the circumferential grooves. A locking plate includes apertures receiving the spools. An actuator is associated with the locking plate and a latch. Pressing and releasing the buttons causes translation of the spool rotationally orienting a notch to be adjacent to the locking plate. The locking plate only moves into an unlocked position, when driven by the actuator disengaging the latch and unlocking the lock if all of the notches which are adjacent to the locking plate are in a unlocked rotational orientation.

1 . A lock comprising:
 a housing having a front section comprising a plurality of apertures therethrough;   a plurality of buttons disposed through the apertures in the front section of the housing, each button comprising a shank and a leg spaced from the shank and having an axis along which each of the buttons may be axially pressed between an un-pressed position and a pressed position;   a biasing member associated with each of the plurality of buttons, configured to bias the buttons towards the un-pressed position;   at least one rod mounted in the housing, each rod extending generally perpendicular to the shanks of the buttons;   a plurality of ratchet sleeves disposed on each rod, each of the ratchet sleeves comprising a tubular portion and at least two teeth;   a plurality of locking wheels, each locking wheel comprising a radial notch, wherein each of the locking wheels are configured to sit on the tubular portion of one of the plurality of ratchet sleeves, wherein the tubular portion and the locking wheel each comprise a plurality of interengaging elements such that, in use, the locking wheel does not rotate with respect to the ratchet sleeve;   a locking plate disposed within the housing, the locking plate comprising a plurality of projections; and   an actuator associated with the locking plate and a latch, wherein the actuator is configured to move the locking plate;   wherein pressing one of the buttons causes the leg of the button to engage one of the teeth of a ratchet sleeve, thereby rotating the ratchet sleeve about the rod until the leg is operable to engage the adjacent tooth; and   wherein, if one or more of the plurality of buttons are pressed a predetermined number of times the radial notch of each locking wheel is aligned with the corresponding projection of the locking plate, such that when the actuator is actuated in a first direction the locking plate is moved from a first position to a second position and the latch is disengaged, thereby unlocking the lock.   
     
     
         2 . The lock of  claim 1 , in which each biasing member comprises a compression spring. 
     
     
         3 . The lock of  claim 1  in which the pressing of the one or more of the plurality of buttons a predetermined number of times defines a code comprising a combination of at least four button presses. 
     
     
         4 . The lock of  claim 1 , in which the number of teeth of the ratchet sleeves determines the number of different possible incremental rotational positions of the ratchet sleeve, and each ratchet sleeve has at least three teeth. 
     
     
         5 . The lock of  claim 1 , comprising at least one common rod on which a plurality of the ratchet sleeves and locking wheels are disposed, wherein each common rod extends generally perpendicular to the shanks of the buttons. 
     
     
         6 . The lock of  claim 5 , in which there are at least two common rods which are adjacent and extend in parallel directions. 
     
     
         7 . The lock of  claim 1 , in which the leg of each button extends substantially parallel to the shank, the shank being coaxial with the axis. 
     
     
         8 . The lock of  claim 1 , in which the leg of each button extends at an angle to the shank. 
     
     
         9 . The lock of  claim 1 , in which the locking plate comprises a plurality of holes, each hole sized to receive the shaft of one of the plurality of buttons therethrough, the holes being arranged such that, when the locking plate is in the first position the shafts of each of the buttons are configured to pass through one of the holes. 
     
     
         10 . The lock of  claim 9 , in which, if the actuator is actuated to move the locking plate from the first position to the second position when the radial notches in the locking wheels are not aligned with the projections in the locking plate, the locking wheels block the locking plate so that it is in a blocking position where it cannot reach the second position and the holes in the locking plate are misaligned from the shafts of the buttons, such that the buttons cannot be pressed. 
     
     
         11 . The lock of  claim 10 , in which, in the blocked position the legs of the buttons cannot contact the ratchet sleeves. 
     
     
         12 . The lock of  claim 1 , comprising a guide plate comprising a plurality of holes through which the shafts of the buttons are arranged to be inserted and disposed in front of the locking plate, such that the shafts of the buttons pass through the guide plate before encountering the locking plate. 
     
     
         13 . The lock of  claim 1 , in which to change the code combination of the lock the actuator has a code setting position in which the actuator is configured to move the locking plate to separate the locking wheels from the interengaging elements on the tubular portions of the ratchet sleeves. 
     
     
         14 . The lock of  claim 13 , in which the actuator is configured in the code setting function, to move in the opposite direction compared to when the actuator is actuated in the first direction. 
     
     
         15 . A lockable enclosure designed to contain one or more articles, the lockable enclosure comprising a lock comprising:
 a housing having a front section comprising a plurality of apertures therethrough;   a plurality of buttons disposed through the apertures in the front section of the housing, each button comprising a shank and a leg spaced from the shank and having an axis along which each of the buttons may be axially pressed between an un-pressed position and a pressed position;   a biasing member associated with each of the plurality of buttons, configured to bias the buttons towards the un-pressed position;   at least one rod mounted in the housing, each rod extending generally perpendicular to the shanks of the buttons;   a plurality of ratchet sleeves disposed on each rod, each of the ratchet sleeves comprising a tubular portion and at least two teeth;   a plurality of locking wheels, each locking wheel comprising a radial notch, wherein each of the locking wheels are configured to sit on the tubular portion of one of the plurality of ratchet sleeves, wherein the tubular portion and the locking wheel each comprise a plurality of interengaging elements such that, in use, the locking wheel does not rotate with respect to the ratchet sleeve;   a locking plate disposed within the housing, the locking plate comprising a plurality of projections; and   an actuator associated with the locking plate and a latch, wherein the actuator is configured to move the locking plate;   wherein pressing one of the buttons causes the leg of the button to engage one of the teeth of a ratchet sleeve, thereby rotating the ratchet sleeve about the rod until the leg is operable to engage the adjacent tooth; and   wherein, if one or more of the plurality of buttons are pressed a predetermined number of times the radial notch of each locking wheel is aligned with the corresponding projection of the locking plate, such that when the actuator is actuated in a first direction the locking plate is moved from a first position to a second position and the latch is disengaged, thereby unlocking the lock. wherein the latch of the lock must be disengaged to gain access to the articles.   
     
     
         16 . The lockable enclosure of  claim 15 , wherein the door of the lockable enclosure comprises at least one elongate member arranged to extend into the internal cavity of the body of the lockable enclosure when the door is in a closed position, wherein the at least one elongate member consists essentially of one or more materials which are harder than high speed steel (HSS). 
     
     
         17 . The lockable enclosure of  claim 16 , wherein the at least one elongate member comprises, or consists essentially of, silicon nitrated (Si3Ni4) steel and wherein the body and/or door of the lockable enclosure comprise, or consist essentially of, zinc or a zinc alloy.