You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a pushbutton lock and particularly to a pushbutton lock coupling with a handle lock to facilitate operation. 
         [0003]    2. Description of the Prior Art 
         [0004]    Referring to  FIG. 11 , a conventional pushbutton lock  91  is installed on a door  90 . To do unlocking, first the pushbutton lock  91  has to be unlocked by turning a rotary knob  911  to retract a dead bolt  912 , then a handle lock  92  is turned to retract a latch bolt  921  to control a switch of the door  90  to allow the door to be opened or closed. Reference of such a pushbutton lock  91  can be found in Taiwan patent publication No. 219085. 
       SUMMARY OF THE INVENTION 
       [0005]    In view of the conventional pushbutton lock set forth above has to couple with a handle lock when in use, not only installation cost is higher, daily opening and closing of the door involve an additional process and is not convenient, the present invention aims to provide a pushbutton lock that is coupled with a handle lock to make use and operation more convenient. The pushbutton lock according to the invention includes an outer handle assembly, an outer lock case, a first control assembly, a second control assembly, a bolt assembly, a cam assembly, an inner lock case and an inner handle assembly. The first control assembly and the second control assembly form a chain movement through the cam assembly. After unlocking the door can be directly opened through an outer handle. The invention further has lock blades that may be altered to reset the number. Moreover, a clear pushbutton is provided to clear and correct mistaken depression of the pushbuttons. Thus use and operation of the pushbutton lock are more convenient. 
         [0006]    The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of the invention. 
           [0008]      FIG. 2  is an exploded view of the invention. 
           [0009]      FIG. 3  is a fragmentary sectional view of the invention. 
           [0010]    FIG.  4 - a  is a schematic view of an embodiment of the lock blade of the invention. 
           [0011]    FIG.  4 - b  is a schematic view of another embodiment of the lock blade of the invention. 
           [0012]      FIG. 5  is a schematic view of the invention showing operating condition- 1 . 
           [0013]      FIG. 6  is a schematic view of the invention showing operating condition- 2 . 
           [0014]      FIG. 7  is a schematic view of the invention showing operating condition- 3 . 
           [0015]      FIG. 8  is a schematic view of the invention showing operating condition- 4 . 
           [0016]      FIG. 9  is a schematic view of the invention showing operating condition- 5 . 
           [0017]      FIG. 10  is a schematic view of the invention showing operating condition- 6 . 
           [0018]      FIG. 11  is a schematic view of a conventional pushbutton lock. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    Referring to  FIGS. 1 and 2 , the pushbutton lock A according to the invention includes an outer handle assembly  1 , an outer lock case  2 , a first control assembly  3 , a second control assembly  4 , an inner lock case  5 , an inner handle assembly  6 , a bolt assembly  7 , and a cam assembly  8 . 
         [0020]    The outer handle assembly  1  includes an outer handle  11 , an outer hub  12 , a lock  13 , an outer torsional spring S 8  and a first inner coupling pad  14  that are installed on the outer lock case  2  by latching a first clip ring C 1 . 
         [0021]    The outer lock case  2  has a plurality of pushbutton ports  21  and an outer axle hole  22 . 
         [0022]    The first control assembly  3  includes: 
         [0023]    a plurality of pushbuttons  31  installed in the pushbutton ports  21 . Each of the pushbuttons  31  is pushed outwards by a first spring S 1  in normal conditions, and assigned with a code (including numeral codes  0 ,  1 , . . . ,  9 , and character codes X, Y, Z, C); 
         [0024]    a plurality of lock blades  32  (referring to FIG.  4 - a ) each having a first hook end  321 , a second hook end  322 , a first notch  325  and a second notch  326  on two ends. There also is a middle notch  323  between the first hook end  321  and the second hook end  322  that is closer to the second hook end  322 . Each lock blade also has two retaining bulged spots  324  on two sides of the middle notch  323 ; 
         [0025]    a first anchor plate  33  which has a plurality of first insertion slots  331  corresponding to the pushbuttons  31  to be inserted by the lock blades  32 ; 
         [0026]    a first sliding plate  34  which has a plurality of second insertion slots  342  corresponding to the pushbuttons  31  to be inserted by the lock blades  32 , a first lug  343  on each of two sides to be pushed by a second spring S 2  to drive the first sliding plate  34  downwards in normal conditions, and a first lower bucking portion  341  on a lower edge; and 
         [0027]    a first covering plate  35  which has a plurality of third insertion slots  351  corresponding to the pushbuttons  31  to be inserted by the lock blades  32 , and a plurality of fastening holes  352  to be fastened by corresponding bolts B to finish assembly of the first control assembly  3 . 
         [0028]    The second control assembly  4  includes: 
         [0029]    a second anchor plate  41  which has a plurality of fourth insertion slots  411  corresponding to the pushbuttons  31  to be inserted by the lock blades  32 ; 
         [0030]    a base dock  42  which has a plurality of insertion slot seats  421  to be inserted by the lock blades  32  and hold a fourth spring S 4 , and a holding trough (not shown in the drawings) at four corners to hold a third spring S 3  to facilitate separation of the first control assembly  3  and the second control assembly  4  after assembly; 
         [0031]    a second sliding plate  43  which has a plurality of fifth insertion slots  431  corresponding to the pushbuttons  31  to be inserted by the lock blades  32 , and a second lower bucking portion  432  on a lower end; 
         [0032]    a third sliding plate  44  which has a plurality of sixth insertion slots  441  corresponding to the pushbuttons  31  to be inserted by the lock blades  32 , a holding trough  443  on one side of each sixth insertion slot  441  to hold a sixth spring S 6  (referring to  FIG. 5 ), and a second lug  442  on each of two sides to hold a fifth spring S 5  to drive the third sliding plate  44  downwards in the normal conditions; and 
         [0033]    a second covering plate  45  which has a plurality of apertures  451  corresponding to the pushbuttons  31 , and a plurality of fastening holes  452  to be fastened by corresponding bolts B to finish assembly of the second control assembly  4 . 
         [0034]    The inner lock case  5  is corresponding to the outer lock case  2  and installed on an inner side of the door, and has an inner axle hole  51 . 
         [0035]    The inner handle assembly  6  includes an inner handle  61 , an inner hub  62 , an inner torsional spring S 7  and a second inner coupling pad  63  that are installed on the inner lock case  5  by latching a second clip ring C 2 . 
         [0036]    The bolt assembly  7  has a bolt seat  71  with an axle opening  711  formed thereon to be run through by a linkage bar  72  to couple with a third anchor plate  73  on one side. 
         [0037]    The cam assembly  8  has a protrusive portion  811  on one side and an axle hole  813  formed thereon. The protrusive portion  811  is wedged in an axle hole  731  of the third anchor plate  73 . The cam  81  further has a symmetrical protrusive rim  812  on the periphery, and has the interior holding at least in this order a ninth spring S 9  and an inner rotary tray  82 , and is covered by an outer rotary tray  83  which has a plurality of outer ratchet teeth  831  engageable with inner ratchet teeth  821  formed on the inner rotary tray  82 . 
         [0038]    After assembly, referring to  FIG. 3 , changing of the unlocking push number is done mainly by altering the insertion direction of the first hook end  321  and the second hook end  322  of the lock blades  32 . Namely the lock blades  32  may be installed in two ways, one for an opening condition (referring to FIG.  4 - a ), another for a closing condition (referring to FIG.  4 - b ). In the closing condition, the middle notch  323  of the lock blade  32  latches and stops the first sliding plate  34  from sliding, thus its first lower bucking portion  341  presses the cam  81  to prohibit it from turning, and the outer handle  11  also cannot be turned to become a locking condition. 
         [0039]    To do unlocking, first depress the pushbuttons  31  according to a preset number, the first hook end  321  of the corresponding lock blades  32  is moved backwards and engaged with the corresponding sixth spring S 6  of the third sliding plate  44  (referring to  FIG. 5 ). The first sliding plate  34  is no longer being harnessed. Hence turning the outer handle  11  can drive the cam  81 . The protrusive rim  812  pushes the first sliding plate  34  upwards (referring to  FIGS. 6 and 7 ), and the linkage bar  72  is synchronously driven to retract the latch bolt  712  of the bolt seat  71  rearwards (not shown in the drawings), then the unlocking condition is accomplished. While the cam  81  is turning, the protrusive portion  812  also pushes the third sliding plate  44  upwards (referring to  FIGS. 8 and 9 ), the first notch  325  of the first hook end  321  escapes the latching of the sixth spring S 6  (referring to  FIG. 10 ), hence the lock blade  32  receives the elastic returning force of the fourth spring S 4  to drive the pushbutton  31  to its original position through the elastic force of the first spring S 1 . 
         [0040]    In the event that a mistaken number is entered by users, one of pushbuttons  31  marked with “C” can be depressed to clear the situation to redo entering operation for the correct number. When the pushbutton  31  marked with “C” is depressed, as the corresponding third sliding plate  44  has a sloped boss  444  on the sixth insertion plate  441  (referring to  FIG. 10 ), the second hook end  322  of the depressed pushbutton  31  marked with “C” pushes the sloped boss  444  to move the third sliding plate  44  upwards to force the lock blade  32  that originally latched on the sixth spring S 6  to escape. Thus a desired number can be entered through the pushbuttons again. 
         [0041]    In short, the pushbutton lock of the invention allows the outer handle to directly open the door after unlocking. The arrangement of the lock blades can be changed to alter the setting number. By depressing the clear pushbutton mistaken entering number can be cleared and corrected. It is more convenient to use, and offers a significant improvement over the conventional techniques.

Summary:
A pushbutton lock coupling with a handle lock includes an outer handle assembly, an outer lock case, a first control assembly, a second control assembly, a bolt assembly, a cam assembly, an inner lock case and an inner handle assembly. The first control assembly and the second control assembly form a chain movement through the cam assembly. After unlocking the door can be directly opened through an outer handle. The pushbutton lock further has lock blades with alterable arrangement to reset the number. Moreover, a clear pushbutton is provided to clear and correct mistaken depression of the pushbuttons. Thus use and operation of the pushbutton lock are more convenient.