Patent Publication Number: US-9890560-B2

Title: Locking apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/361,504, filed on Jul. 13, 2016 and U.S. Provisional Patent Application No. 62/419,448, filed on Nov. 8, 2016, the entire contents of which are hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present application relates to locking apparatus, particularly, but not exclusively, locking apparatus for use on a mechanical combination door lock. 
     BACKGROUND 
     It is desirable in many circumstances to allow building entry doors, windows, cupboards etc. to be opened only by those who have been authorised to do so. One way of achieving this is to use a mechanical locking mechanism which requires a predetermined code to be entered before it can be unlocked and mechanical combination door locks are widely used for this purpose. 
     Such locks are typically provided with a series of alphanumeric buttons (often 4, 6, 8, 10 or 12 buttons) and a knob or handle which can be grasped by the user. In operation, an authorised user dials the correct passcode into the mechanism, then turns the knob or handle in order to unlock the mechanism. The passcode on such locks can typically be changed to suit a user&#39;s preference by dismantling a portion of the lock (normally from the rear) and switching the orientation of certain locking pins provided in the body of the lock; however, for security reasons this normally requires that the lock is first opened to gain access to the rear/inside of the door before then removing the lock from its mount on the door. This can be relatively time consuming, is often inconvenient, and requires a degree of skill and care in order to correctly change the code and to correctly re-mount the lock back on the door. 
     SUMMARY 
     According to one aspect, there is provided a locking apparatus which may include:
         a cover plate coupled with a base;   a plurality of buttons provided on a cover plate;   an actuating hub rotatably mounted on the base, a circumference of the actuating hub formed with a recessed portion defining two projections;   a grip handle connected with the actuating hub;   a first control plate disposed adjacent to the actuating hub and having one end formed with a raised portion, the two projections of the actuating hub being abutted against two sides of the raised portion of the first control plate respectively, such that when the actuating hub rotates clockwise or anticlockwise, one of the two projections presses against a corresponding one of the two sides of the raised portion of the first control plate, the first control plate further including two longitudinal side plates, and a plurality of teeth projecting inwardly from each of the two longitudinal side plates;   first and second parallel locking tumblers, each having a central axle mounted on the base;   a series of button engagement disc clutch plates mounted on the central axle of each locking tumbler, each button engagement disc clutch plate including a pair of button pin engagement levers for engagement therein between with a protruded portion of a button pin of the button; and   a series of coding disc clutch plates mounted on the central axle of each locking tumbler, and engaging respectively with the series of button engagement disc clutch plates, each coding disc clutch plate including a cut-out aperture;   whereby pressing a selected group of the buttons, which correspond to an access code, rotates their respective button engagement disc clutch plates and in turn their respective coding disc clutch plates such that the cut-out apertures align with the teeth of the first control plate, thereby allowing movement of the first control plate and rotation of the actuating hub when the grip handle is rotated.       

     According to another aspect, there is provided a locking apparatus which may include:
         a plurality of buttons provided on a cover plate which is coupled with a base;   an actuating hub rotatably mounted on the base, a circumference of the actuating hub formed with a recessed portion defining two projections;   a grip handle connected with the actuating hub;   a first control plate disposed adjacent to the actuating hub and having one end formed with a raised portion, the two projections of the actuating hub being abutted against two sides of the raised portion of the first control plate respectively, such that when the actuating hub rotates clockwise or anticlockwise, one of the two projections presses against a corresponding one of the two sides of the raised portion of the first control plate, the first control plate further including two longitudinal side plates, and a plurality of teeth projecting inwardly from at least one of the two longitudinal side plates;   at least one locking tumbler, the or each locking tumbler having a central axle mounted on the base;   a series of button engagement disc clutch plates mounted on the central axle of the or each locking tumbler, each button engagement disc clutch plate including a pair of button pin engagement levers for engagement therein between with a protruded portion of a button pin of the button; and   a series of coding disc clutch plates mounted on the central axle of the or each locking tumbler, and engaging respectively with the series of button engagement disc clutch plates, each coding disc clutch plate including a cut-out aperture;   whereby pressing a selected group of the buttons, which correspond to an access code, rotates their respective button engagement disc clutch plates and in turn their respective coding disc clutch plates such that the cut-out apertures align with the teeth of the first control plate, thereby allowing movement of the first control plate and rotation of the actuating hub when the grip handle is rotated.       

     In one embodiment, the locking apparatus may include a pair of parallel locking tumblers, and the plurality of teeth may project inwardly from each of the two longitudinal side plates of the first control plate. 
     In one embodiment, the locking apparatus may further include a code change button, and an angled slide provided underneath the code change button, the angled slide being formed with a slanted surface which engages with an inner edge of a second control plate. 
     In one embodiment, wherein the second control plate may include a series of tabs engaging respectively with the series of coding disc clutch plates on the central axle of each locking tumbler; whereby when the code change button is pressed after the selected group of the buttons have been pressed, the angled slide urges the second control plate to make a translational movement relative to the base, resulting in that the series of coding disc clutch plates dislocate from the series of button engagement disc clutch plates by the series of tabs, thereby allowing a user to change the access code by selecting and pressing another group of the buttons, and changing angular orientation of the button engagement disc clutch plates relative to their corresponding coding disc clutch plates. 
     In one embodiment, each button engagement disc clutch plate may include three recessed portions formed along a peripheral portion thereof, and each coding disc clutch plate may include two projected portions formed along a peripheral portion thereof; wherein when the two projected portions are engaged with two of the three recessed portions, the cut-out aperture of the coding disc clutch plate is aligned with the teeth of the first control plate, and when the two projected portions are engaged with another two of the three recessed portions, the cut-out aperture of the coding disc clutch plate is out of alignment with the teeth of the first control plate. 
     In one embodiment, a primary spring and a secondary spring are provided around the button pin of each button to resiliently return the button to its original position after having been pressed and released by the user. 
     In one embodiment, a tertiary spring is provided between adjacent sets of engaging button engagement disc clutch plate and coding disc clutch plate on each central axle for biasing each coding disc clutch plate against its engaging button engagement disc clutch plate. 
     In one embodiment, a pair of quaternary springs is provided on the first control plate for biasing the first control plate towards the actuating hub. 
     In one embodiment, the base is provided with a locking block including a block body with an enlarged head, the block body being inserted into a bore formed at the base, such that an inner end of the block body abuts against an inner end of the angled slide of the code change button, and an outer end of the block body is provided with the enlarged head located on an outer surface of the base; wherein the locking block is held in place within the bore when the base of the locking apparatus is held against and secured on a panel, and the locking block drops out of the bore after the locking apparatus is detached from the panel, and the inner end of the angled slide is inserted into the bore through an opening by pressing the code change button. 
     In one embodiment, the locking apparatus may further include a reset button; a reset slide provided underneath the reset button; a coding bar mounted on the base between the first and second locking tumblers and formed with a sloped surface facing the reset slide; and a quinary spring mounted between one end of the coding bar and the base for biasing the coding bar in one direction; wherein when the selected group of the buttons are pressed, their respective coding disc clutch plates rotate and engage with the coding bar, and when the reset button is pressed, the reset slide presses on the sloped surface and urges the coding bar to move in an opposite direction against biasing force of the quinary spring, thereby releasing the coding disc clutch plates to their initial positions, and when the reset button is released, the coding bar returns to its initial position. 
     In one embodiment, the protruded portion of each button pin protrudes perpendicularly from the button pin of the button, and the pair of button pin engagement levers projects in a direction radially outwardly from the central axle. 
     In one embodiment, the selected group of the buttons may include one or more of the buttons provided on the cover plate. 
     Further features and advantages of the aspects of the present application will become apparent from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present application will now be described by way of example only, with reference to the following diagrams, in which: 
         FIG. 1  is a schematic perspective illustration of an assembled locking apparatus according to an embodiment of the present application; 
         FIG. 1 a    is a schematic perspective illustration of an assembled locking apparatus according to another embodiment of the present application; 
         FIG. 2  is a schematic perspective illustration of an embodiment of the locking apparatus where a protective cover has been removed for illustrative purposes; 
         FIG. 3  is a schematic bottom plan view illustration of the locking apparatus in a normal locking/unlocking mode where coding tumbler clutch plates and button engagement clutch plates are located in abutment with one another; 
         FIGS. 3 a  and 3 b    are schematic perspective illustrations of the locking apparatus in a code unchangeable condition and a code changeable condition respectively; 
         FIGS. 3 c  and 3 d    are enlarged schematic perspective illustrations of the locking apparatus of  FIGS. 3 a  and 3 b    in a code unchangeable condition and a code changeable condition respectively; 
         FIG. 4  is a schematic bottom plan view illustration of the locking apparatus in a code change mode where the coding tumbler clutch plates and button engagement clutch plates have been translated out of engagement with one another; 
         FIG. 5  is a partial cross sectional illustration of coding tumbler clutch plates and button engagement clutch plates viewed in the direction indicated as A-A in  FIG. 2  and prior to entry of an unlock code where a coding tumbler clutch plate is blocking movement of a locking tooth of a lock control plate; 
         FIG. 6  is a partial cross sectional illustration of coding tumbler clutch plates and button engagement clutch plates viewed in the direction indicated as A-A in  FIG. 2  and after entry of an unlock code where the coding tumbler clutch plate allows a locking tooth of the lock control plate to pass through an aperture provided at one side thereof; 
         FIGS. 6 a -6 d    are respective front, left, rear and right side illustrations of a single coding tumbler clutch plate and a corresponding single button engagement clutch plate positioned in a first angular orientation relative to one another prior to a user conducting a code change operation; 
         FIGS. 7 a -7 d    are respective front, left, rear and right side illustrations of a single coding tumbler clutch plate and a corresponding single button engagement clutch plate positioned in a second angular orientation relative to one another following a user having conducted a code change operation; 
         FIG. 8  is an upper schematic perspective illustration of first and second coding tumblers and their respective buttons in isolation from the apparatus; 
         FIG. 9  is an underside schematic perspective illustration of the arrangement of  FIG. 8 ; 
         FIG. 10 a    is an end view of the coding tumblers where the interaction between a locking block and an angled slide of a code change button is illustrated; 
         FIG. 10 b    is an end view of the coding tumblers where the locking block is being pushed out by the angled slide of the code change button; 
         FIG. 11 a    is a schematic perspective illustration of the locking apparatus showing a reset slide of a reset button urging a spring-biased coding bar in one direction; and 
         FIG. 11 b    is a schematic perspective illustration of the locking apparatus showing the coding bar returned to its original position after release of the reset button. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to a preferred embodiment of the locking apparatus, examples of which are also provided in the following description. Exemplary embodiments of the locking apparatus are described in detail, although it will be apparent to those skilled in the relevant art that some features that are not particularly important to an understanding of the locking apparatus may not be shown for the sake of clarity. 
     Furthermore, it should be understood that the locking apparatus is not limited to the precise embodiments described below and that various changes and modifications thereof may be effected by one skilled in the art without departing from the scope of the protection. For example, elements and/or features of different illustrative embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims. 
     As shown in  FIG. 1 , the locking apparatus  10  of the present application may include a strong and durable cover plate  12 , a plurality of key press buttons  14 , and an opening/closing knob or grip handle  16 . The key press buttons  14  may be provided with a number of letters/numerals (not shown) such that, once a user has keyed in the correct code, the user is then able to rotate the grip handle  16  in order to unlock the lock and gain access to the otherwise secured area. 
     At least one of the key press buttons may be designated as a code change button  19 . In the present embodiment, this is shown as the bottom button in the first column of buttons; however, this could be provided on any one (or many) of the buttons  14 . 
       FIG. 1 a    shows another embodiment of the grip handle  16 ′ of the locking apparatus  10 . 
     With particular reference to  FIG. 2 , beneath the cover  12 , the locking apparatus  10  may be provided with a base  15  upon which may be mounted an inner actuating hub  17 , first and second parallel code operated locking tumblers  18 ,  20 , a first control plate  26 , a second control plate  22  and a series of button pins  28  which connect at their upper end to the buttons  14  and at their lower/intermediate ends to the locking tumblers  18 ,  20  as will be described subsequently. 
     The base  15  allows the locking apparatus  10  to be securely attached to the surface of a door or other such arrangement and provides a secure base upon which the other components of the apparatus are mounted. 
     The inner actuating hub  17  may be directly connected to the outer grip handle  16 . Referring to  FIG. 3 , a circumference of the actuating hub  17  may be formed with a recessed portion  17   a  which defines two projections  17   b  abutting against two sides of a raised portion  26   a  formed at one end of the first control plate  26  respectively such that when the actuating hub  17  rotates clockwise or anticlockwise, one of the two projections  17   b  presses against a corresponding one of the two sides of the raised portion  26   a  of the first control plate  26  (and move it if the apparatus is unlocked yet be prevented from such movement if the apparatus is locked as described subsequently). 
     An angled slide  32  may be provided beneath the code change button  19 . The angled slide  32  may be formed with a slanted surface  33 , as shown in  FIG. 2 , which can engage with an inner edge  24  of the second control plate  22  in a sliding fashion, whereby downward movement of the angled slide  32  results in a corresponding translational movement of the second control plate  22  in the direction indicated by arrow X in  FIG. 2 . 
     As shown in  FIG. 2 , the first control plate  26  can be a longitudinal structure having two longitudinal side plates  27 . A series of teeth  42  may extend inwardly from each of the two longitudinal side plates  27 . The first control plate  26 , the two side plates  27  and the teeth  42  may be integrally formed as one piece. The first control plate  26  and the second control plate  22  may move independently in a longitudinal direction. 
     With reference to  FIG. 3 , the locking tumblers  18 ,  20  each comprise a central axle  34  mounted to the base  15  and upon which are mounted a series of coding disc clutch plates  36  and a series of corresponding button engagement disc clutch plates  38 . As best illustrated in  FIG. 5 , each coding disc clutch plate  36  comprises at least one cut-out aperture  37 , and each button engagement disc clutch plate  38  comprises a pair of button pin engagement levers  40  which may project in a direction radially outwardly from the central axle  34 . A protruded portion  29  ( FIGS. 6 a -6 b   ) may protrude perpendicularly from the button pin  28  and can be positioned between the pair of button pin engagement levers  40 . 
     Although it has been shown and described that there are two locking tumblers, it is understood by one skilled in the art that the locking apparatus of the present application may have only one locking tumbler, and the plurality of teeth may be formed only on one longitudinal side plate of the control plate. 
     The relative angular position of each coding disc clutch plate  36  relative to each button engagement disc clutch plate  38  is what determines whether the teeth  42  of the first control plate  26  are able to translate along the length of the apparatus or not since, in certain angular positions (such as that shown at the left side of  FIG. 5 ), the coding disc clutch plate  36  will block such movement of the teeth  42 ; whereas, in other positions (such as that shown at the right side of  FIG. 5 ), the aperture  37  in the coding disc clutch plate  36  will align with the teeth  42  in order to allow such translating movement. 
     With reference to  FIG. 8 , primary springs S 1  and secondary springs S 2  may be provided around the button pins  28  in order to resiliently return the buttons  14  to their original position after having been pressed and released by a user. 
     The locking and unlocking function of the locking apparatus will now be described. 
     In use, prior to a user entering the correct access code, if the user attempts to rotate the grip handle  16  (and hence the underlying actuating hub  17 ) one of the two projections  17   b  (depending upon which direction the user turns the grip handle  16 ) will press against a corresponding one of the two sides of the raised portion  26   a  of the first control plate  26 . However, the first control plate  26  cannot move due to at least one of its teeth  42  being prevented from translating along the length of the apparatus by at least one of the coding disc clutch plates  36  as previously described. This therefore prevents the handle  16  from being rotated and hence prevents the lock from being opened. 
     With reference to  FIG. 1 , the code change button  19  cannot be depressed prior to entry of the correct access code since downward movement of the button is prevented by the engagement between the angled slide  32  and the inner edge  24  of the second control plate  22  (which itself cannot move until the correct access code has been entered. 
     One or more buttons might be included in the correct access code, e.g. the code might be “1234”. Upon pressing a selected group of the buttons  14 , which correspond to the access code, each button pin  28  rotates the aperture  37  of each of the four coded clutch plates  36  such that the apertures  37  align with the teeth  42 . Once this condition has been achieved for each coded clutch plate, if the user then rotates the grip handle  16 , one of the two projections  17   b  will press against a corresponding one of the two sides of the raised portion  26   a  and therefore will be able to move the first control plate  26  because the teeth  42  are no longer blocked by the coding discs clutch plates  36 . This allows a locking bolt of the door to be opened. In this way it can be understood that the angular orientation of each coding disc clutch plate  36  relative to its respective button engagement disc clutch plate  38  is what determines whether the lock can be opened or not. 
     When a user wishes to change the access code on the locking apparatus to a different code of their choosing, they must first enter the correct existing access code to do so. If they do not first enter the correct existing access code they cannot depress the code change button  19  (due to the second control plate  22  not being able to translate) and hence will be unable to change the code of the locking apparatus. 
     With the correct access code entered, the user is able to depress the code change button  19 . Doing so forces the angled slide  32  down against the inner edge  24  of the second control plate  22 . This co-operation between the angled slide  32  and the inner edge  24  in turn translates each of the coding disc clutch plates  36  from the position shown in  FIG. 3  to the position shown in  FIG. 4  such that the coding disc clutch plates  36  are effectively dislocated from the button engagement disc clutch plates  38  by means of a series of corresponding tabs  48 , as illustrated in  FIGS. 3 a -3 d   , formed on the second control plate  22  and engaging with the series of coding disc clutch plates  36  respectively. The user then selects a new code by pressing whichever buttons  14  they desire (e.g.  5678 ) in order to change the angular orientation of certain button engagement disc clutch plates  38  relative to their corresponding coding disc clutch plates  36 . 
       FIGS. 6 a -6 d    and  FIGS. 7 a -7 d    show the difference in angular orientation present in the coding disc clutch plates  36  and the button engagement disc clutch plates  38 . In the present embodiment, each button engagement disc clutch plate  38  may include three recessed portions  35  formed along a peripheral portion thereof, and each coding disc clutch plate  36  may include two projected portions  39  formed along a peripheral portion thereof. 
     When the two projected portions  39  are engaged with two of the three recessed portions  35 , as shown in  FIG. 6 c   , the cut-out aperture  37  of the coding disc clutch plate  36  is aligned with the teeth  42  of the first control plate  26 . When the two projected portions  39  are engaged with another two of the three recessed portions  35 , as illustrated in  FIG. 7 c   , the cut-out aperture  37  of the coding disc clutch plate  36  is out of alignment with the teeth  42  of the first control plate  26 . 
     As best illustrated in the enlarged views in  FIGS. 3 c  and 3 d   , the second control plate  22  may be formed with a series of tabs  48  engaging respectively with the series of coding disc clutch plates  36  mounted on the central axle  34  of each locking tumbler  18 ,  20 . When the code change button  19  is pressed after the selected group of the buttons  14 , which correspond to the access code, have been pressed, the angled slide  32  urges the second control plate  22  to make a translational movement relative to the base  15 , resulting in that the series of coding disc clutch plates  36  are dislocated from the series of button engagement disc clutch plates  38  by the series of tabs  48 , thereby allowing a user to change the access code by selecting and pressing another group of the buttons  14 , and changing angular orientation of the button engagement disc clutch plates  38  relative to their corresponding coding disc clutch plates  36 . 
     The locking apparatus of the present application has the advantage of allowing the access code of the locking tumbler to be quickly and easily changed by a user without requiring the locking apparatus to be removed or dismantled. 
     It is understood that resilient means may be provided within the body of the apparatus in order to resiliently bias components of the apparatus in the open, closed, engaged or disengaged configurations. The resilient means may include coiled springs or any other appropriate means. 
     When the coding disc clutch plates  36  translate to the left of  FIG. 3  or  FIG. 4 , the button engagement disc clutch plates  38  do not move since they are held in position by the button pins  28 . Each button pin  28  is returned to its original position by the action of primary and secondary springs S 1  and S 2  ( FIG. 8 ). 
     Once a new code is entered into the apparatus, the apparatus is then returned to its normal operating mode by the action of tertiary springs S 3  ( FIG. 9 ). 
     When the correct access code has been pressed, the tabs  42  are allowed to move freely between the coding disc clutch plates  36  through the cut-out apertures  37 . The coding disc clutch plates  36  are allowed to be moved by their corresponding tabs  48 , thereby dislocating the coding disc clutch plates  36  from the button engagement disc clutch plates  38 , and allowing angular orientation of the coding disc clutch plates  36  (coded or non-coded) to be changed. 
     A pair of quaternary springs S 4  ( FIG. 4 ) can be provided on the first control plate  26  for biasing the first control plate  26  towards the actuating hub  17 . 
     With reference to  FIGS. 10 a  and 10 b   , a locking block  50  may be provided at the base  15  of the apparatus. The locking block  50  may have a block body  52  formed with an enlarged head  54 . The block body  52  can be inserted into a bore  56  formed at the base  15 . An inner end of the block body  52  can abut against an inner end of the angled slide  32  of the code change button  19 , and an outer end of the block body  52  can be provided with the enlarged head  54  located on an outer surface of the base, as depicted in  FIG. 10   a.    
     The locking block  50  can be held in place within the bore  56  when the base  15  of the locking apparatus  10  is held against and secured on any access panel, such as a door panel (not shown). The locking block  50  can drop out of the bore  56  after the locking apparatus  10  is detached from the panel, and the inner end of the angled slide  32  is inserted into the bore  56  through an opening  58  by pressing the code change button  19 , as illustrated by the arrows in  FIG. 10   b.    
     The previous access code may be cancelled by pressing a reset button  60 , as shown in  FIGS. 1 and 1   a , which can bring all angular orientations in line with one another in preparation for selection of a new access code. In the present embodiment, the reset button  60  may be provided next to the code change button  19 . 
     As shown in  FIGS. 11 a  and 11 b   , in addition to the reset button  60 , the locking apparatus may also include a reset slide  62  provided underneath the reset button  60 . A coding bar  64  may be mounted on the base  15  between the first and second locking tumblers  18 ,  20 . The coding bar  64  may be formed with a sloped surface  66  facing the reset slide  62 . A quinary spring S 5  may be mounted between one end of the coding bar  64  and the base  15  for biasing the coding bar  64  in one direction. 
     When the selected group of the buttons  14  are pressed, their respective coding disc clutch plates  36  rotate and engage with the coding bar  64 , and when the reset button  60  is pressed, the reset slide  62  presses on the sloped surface  66  and urges the coding bar  64  to move in an opposite direction against the biasing force of the quinary spring S 5 , thereby releasing the coding disc clutch plates  36  to their initial positions. When the reset button  60  is released, the coding bar  64  returns to its initial position under the influence of the quinary spring S 5 . 
     The above described embodiments of the locking apparatus of the present application provide a coded locking apparatus on which the code may be easily changed by a user that is able to enter the correct existing access code. The locking apparatus of the present application achieves this without requiring any dismantling or dismounting of the apparatus. 
     Although particular embodiments of the locking apparatus of the present application have been disclosed herein in detail, this has been done by way of example and for the purposes of illustration only. The aforementioned embodiments are not intended to be limiting with respect to the scope of protection defined in the present application. 
     It is contemplated by a person skilled in the art that various substitutions, alterations, and modifications may be made to the locking apparatus of the present application without departing from the spirit and scope of protection as defined by the appended claims.