Patent Publication Number: US-7900804-B2

Title: Stapler and staple cartridge

Description:
TECHNICAL FIELD 
     The present invention relates to a stapler and a staple cartridge including a guide mechanism of a staple capable of firmly striking out the staple without buckling a leg portion of the staple. 
     BACKGROUND ART 
     There is a stapler of a cartridge type for binding a staple by mounting a cartridge contained with a number of unformed straight staples to a magazine portion of an electric stapler, successively supplying the unformed staple at an inside of the cartridge to a strike out path formed at a front end of a path of supplying the staple of the cartridge, forming the unformed staple in a C-shape by a forming plate immediately before the strike out path and supplying the formed staple to an inside of the strike out path in which a driver plate is moved to slide, striking out the formed staple from the strike out path by the driver plate, and penetrating the staple leg through binding sheets arranged at a lower face of the cartridge. 
     A front end portion of the cartridge contained with the number of staples is formed with the strike out path for striking out a front one of the staples to the binding sheet, and the strike out path is formed between a front end face of the cartridge and a face plate attached to a front end portion of the cartridge. The driver plate driven reciprocally by a motor provided on a main body side of the electric stapler strikes out the staple arranged at the inside of the strike out path by advancing to inside of the strike out path formed at the front end portion of the cartridge and folds to bend a front end of a staple leg penetrated through the binding sheets arranged on a lower face side of the cartridge by a clincher mechanism. 
     According to an electric stapler according to the related art of the application, there is formed an anvil arranged at a lower face of the unformed staple immediately before the strike out path, the unformed staple is formed into a C-shape by the anvil and the forming plate, and the staple formed in the C-shape is supplied to the inside of the strike out path by a pusher arranged on a lower side of the anvil. The pusher is moved back when the unformed staple is formed into the C-shape by the forming plate, engaged with the rear face side of the staple formed in the C-shape and presses the formed staple to a front side by a spring urge force to supply to an inside of a groove formed at a back face of a face plate forming the strike out path. Further, the pusher presses the staple leg portion from the rear face side to guide the struck-out staple leg portion when the staple at the inside of the strike out path is struck out by the driver plate. 
     The pusher is moved back by bringing the staple leg in the midst of being formed by starting to form the unformed staple by the forming plate into contact with the pusher, and presses the staple in a direction of the strike out path by being engaged with the rear face side of the staple formed in the C-shape. When the pusher is moved back, a support force for pushing the staple arranged at the inside of the strike out path and in the midst of being back from the rear face side is lost to bring about a case in which the staple is not guided sufficiently. When a length of the staple leg formed in the C-shape is long, also a thickness of the binding sheets is large and therefore, a large penetration resistance is produced during a time period after landing a front end of the staple leg struck out by pressing a crown portion thereof by the driver plate on a surface of the binding sheets, until penetrating the front end of the staple leg through the binding sheets, a distance between the driver plate and the front end of the staple leg is large and therefore, when the support force from the rear side is lost as described above, jamming is liable to be brought about by buckling the staple leg. 
     Hence, WO2004/048054 discloses a staple in which a pusher is formed with a long guide piece continuous in a staple striking out direction by way of an inclined face to be formed to project integrally to a side of the face plate to advance to between two legs of the staple at the inside of the strike out path, and the staple leg is guided by the guide piece by forming the inclined face at a position of being engaged with the staple when a front end of the staple leg struck out by the driver plate is landed on the binding sheets. 
     However, also according to the electric stapler, the pusher is moved back simultaneously with folding to bend the straight staple into the C-shape by the forming plate on the rear face side of the driver plate and therefore, a front one of the formed staple is liable to be unstable by losing the support invariably. Therefore, there is a case in which the staple is buckled before finishing to penetrate the binding sheets in the midst of being struck out. There is brought about an unstable struck state to cause to bring about a failure in striking such as jamming or the like. 
     DISCLOSURE OF THE INVENTION 
     One or more embodiments of the invention provide a stapler and a staple cartridge having a mechanism for guiding a staple in which when the staple formed in a C-shape is struck out to a strike out path by a driver plate, buckling, jamming or the like of the staple is prevented from being brought about by effectively guiding a staple leg. 
     In accordance with one or more embodiments of the invention, in a stapler, at a front portion of a path of supplying connected staples connected with straight staples, a forming plate of folding to bend to form a front staple into a C-shape and a driver plate for striking out the formed staple are held in a laminated state, the staple in the C-shape formed by the forming plate at an inside of a strike out path formed between a front end face of the supply path and a back face of a face plate arranged on a front side of the supply path is pressed to supply to the inside of the strike out path by a pusher urged by a spring to the face plate, and the staple is struck out by the driver plate. The pusher is made to constitute a first pusher and a second pusher for pressing a leg portion of the staple to the face plate is arranged to align with a side of a staple strike out port of the first pusher. 
     Further, in accordance with one or more embodiments of the invention, the first pusher and the second pusher are formed with press portions for pressing the staple, and both sides of the press portion are formed with guide portions for guiding inner side faces of the two leg portions of the staple at the inside of the strike out path by way of a stepped difference continuously in a direction of striking out the staple. 
     Further, in accordance with one or more embodiments of the invention, a stapler is provided with a path of supplying connected staples, a face plate arranged on a front side of the supply path, a strike out path provided between a front end face of the supply path and the face plate, a first pusher provided at the inside of the strike out path and urged to the face plate, and a second pusher provided at the inside of the strike out path, arranged on a side of a staple strike out port of the first pusher, and urged to the face plate. 
     Further, in accordance with one or more embodiments of the invention, the first pusher and the second pusher are made to be movable independently from each other. 
     Further, in accordance with one or more embodiments of the invention, the stapler is further provided with a forming plate for forming to bend to form a front one staple of the connected staples into a C-shape, and a driver plate held in a state of being laminated with the forming plate for striking out the formed staple. The first pusher presses the formed staple to the face plate, and the second pusher presses a leg portion of the formed staple to the face plate. 
     In accordance with one or more embodiments of the invention, the stapler is further provided with a first press portion formed at the first pusher for pressing the staple, first guide portions formed on both sides of the first press portion by way of a stepped difference for guiding inner side faces of the two leg portions of the staple at the inside of the strike out path, a second press portion formed at the second pusher for pressing the staple, and second guide portions formed on both sides of the second press portion for guiding the inner side faces of the two leg portions of the staple at the inside of the strike out path. 
     In accordance with one or more embodiments of the invention, the first press portion includes a first inclined face and a first engaging face successive to the first inclined face, and the second press portion includes a second inclined face and a second engaging face successive to the second inclined face. 
     In accordance with one or more embodiments of the invention, a side of the strike out path of the first pusher is formed with a first inclined face, and a first engaging face successive to the first inclined face, and a side of the strike out path of the second pusher is formed with a second inclined face, and a second engaging face successive to the second inclined face. 
     In accordance with one or more embodiments of the invention, when the staple at the inside of the strike out path is struck out by the driver plate, and a crown portion of the staple at the inside of the strike out path is engaged with the first engaging face, the first pusher is pushed back against an urge force, and when the forming plate forms the staple at a successive position and the first pusher is further pushed back, the crown portion of the staple at the inside of the strike out path is supported by the second inclined face. 
     Further, in accordance with one or more embodiments of the invention, a staple cartridge is provided with a path of supplying connected staples, a first pusher provided on a lower side of the supply path and urged to a direction of supplying the connected staple, and a second pusher provided on a lower side of the first pusher, urged to the direction of supplying the connected staples and made to be movable independently from the first pusher. 
     Further, in accordance with one or more embodiments of the invention, the first pusher is made to be able to advance and retract to and from a strike out path formed between a front end face of the supply path and a face plate, and the second pusher is made to be able to advance and retract to and from the strike out path. 
     Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       [ FIG. 1(   a )] 
         FIG. 1(   a ) is a perspective view of a staple cartridge according to one or more embodiments of the invention along with a driver plate, a forming plate. 
       [ FIG. 1(   b )] 
         FIG. 1(   b ) is a front view showing the staple cartridge according to one or one or more of the invention along with the driver plate, the forming plate. 
       [ FIG. 2 ] 
         FIG. 2  is a vertical sectional view of the staple cartridge. 
       [ FIG. 3 ] 
         FIG. 3  is a plane view of a front end portion of the staple cartridge. 
       [ FIG. 4 ] 
         FIG. 4  is a perspective view enlarging a front portion of the staple cartridge. 
       [ FIG. 5 ] 
         FIG. 5  is a perspective view of a state of aligning to arrange a first pusher and a second pusher. 
       [ FIG. 6 ] 
         FIG. 6  is a vertical sectional side view enlarging a state before starting a staple binding operation. 
       [ FIG. 7 ] 
         FIG. 7  is a vertical sectional side view enlarging a state in the midst of striking out a staple. 
       [ FIG. 8 ] 
         FIG. 8  is a side view enlarging the state in the midst of striking out the staple. 
       [ FIG. 9 ] 
         FIG. 9  is an enlarged vertical sectional view in finishing to strike out and form the staple. 
     
    
    
     DESCRIPTION OF REFERENCE NUMERALS AND SIGNS 
     s . . . staple 
     s 1  . . . leg portion 
       10  . . . driver plate 
       11  . . . forming plate 
       7  . . . supply path 
       9  . . . strike out path 
       8  . . . face plate 
       15  . . . first pusher 
       16  . . . second pusher 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     One or more embodiments of the invention will be explained in reference to the drawings as follows. 
     Embodiment 
     In  FIG. 1(   a ),  FIG. 1(   b ) and  FIG. 2 , notation  1  designates a cartridge main body, notation  2  designates a refill. The refill  2  contains connected staples  4  connected with a number of unformed straight staples at an inside of a refill case  3  and is formed with a discharge port  6  of the connected staples  4  at a front end thereof. The refill  2  is made to be able to be attached and detached to and from the cartridge main body  1 . The cartridge main body  1  is formed with the supply path  7  of the connected staples  4  continuously from the discharge port  6  of the refill  2  and the face plate  8  is arranged to be orthogonal to the supply path  7  on a front side thereof. Further, as shown by  FIG. 3 , the strike out path  9  of the staple is formed along an inner face of the face plate  8  between a front end face of the supply path  7  and a back face of the face plate  8  arranged on the front side of the supply path  7 . 
     In contrast thereto, the staple cartridge is constituted to be set to a predetermined position of a main body of the electric stapler although not illustrated. As the electric stapler for setting the staple cartridge, there is conceived an electric stapler of an apparatus included type installed into an inside of an apparatus of, for example, a copier, a printer or a facsimile machine for automatically binding together a predetermined number of sheets of sheets copied, printed or received by a facsimile. The electric stapler main body is provided with a feed mechanism for supplying the connected staples  4  at an inside of the staple cartridge to the strike out path  9 , and a strike mechanism for holding to drive the forming plate  11  for forming the unformed staple supplied to the front portion of the supply path  7  in a C-shape and the driver plate  10  for striking out a front one of the staple formed and supplied to the strike out path  9  in a laminated state. Further, a side of the staple cartridge opposed to the driver plate  10  is provided with a clincher member to be able to move in an up and down direction and is constituted to hold a binding sheet P set above a binding base provided at an upper portion of the staple cartridge of the drawing and fold to bend a leg portion of the staple struck out by the driver plate  10 . 
     Further, although the driver plate  10  and the forming plate  11  are supported by a common drive shaft  12 , an end portion flange  11   a  of the forming plate  11  is formed with a long hole  14  prolonged in a strike out direction, and the drive shaft  12  is engaged with the long hole  14 . Therefore, although the driver is reciprocally moved along with the drive shaft  12 , the forming plate  11  is reciprocally moved retardedly relative to the driver plate  10 . 
     Further, the strike out path  9  is formed by a recess groove  13  formed at a back face of the face plate  8  and therefore, the front one of the unformed staple of the connected staples  4  cannot jump to the strike out path  9 . Hence, the front one of the staple is folded to bend at both sides thereof by the forming plate  11  to be formed into a C-shape (a crown portion s 1  and a leg portion s 2  shown in  FIG. 5 ) having a size of being brought to the strike out path  9  and thereafter supplied to the strike out path  9 . The staple s fed to the strike out path  9  is struck out by the driver plate  10 . 
     As shown by  FIG. 4 ,  FIG. 5  and  FIG. 6 , a lower side of the supply path  7  is arranged with the first pusher  15  and the second pusher  16  as means for guiding the staple s slidably along a direction of supplying the connected staples  4 . The first pusher  15  and the second pusher  16  are made to advance and retract to and from inside of the strike out path  9 . The leg portion s 2  of the staple s formed by the forming plate  11  is pushed out to be supplied to the strike out path  9  by the first pusher  15  and the second pusher  16 . The staple is fed to the strike out path  9  and thereafter struck out by the driver plate  10 , in that occasion, a front face and an outer side face of the staple s are guided by the recess groove  13  of the strike out path  9 . In addition thereto, a rear face of the staple s is guided by the first pusher  15  and the second pusher  16 . 
     The first pusher  15  is urged to the face plate  8  by a spring  22 . Both sides of a front face of the first pusher  15  are formed with guide portions  17  (first guide faces  17 ) capable of being engaged with rear faces of the leg portions s 2  of the formed staple, and inner sides of stepped differences  17   a  of the guide portions  17  are continuously formed with an inclined face  18  (first inclined face  18 ) on a side of the supply path  7  and an engaging face  19  (in parallel with an inner face of the face plate  8 ) successive thereto. A center of an end portion of the engaging face  19  (first engaging face  19 ) is formed with an extended portion  20  extended to a side of the second pusher  16 . It is preferable that also the guide portion  17  is continuously formed with an inclined guide face  17   b  on a side of the supply path  7  and a strike out guide face  17   c  in parallel with the inner face of the face plate  8  as shown by  FIG. 5 . 
     Blade pieces  23  are extended to be formed on both outer sides of the guide portions  17 , and upper end edges thereof are formed with inclined faces  24  for pushing back the first pusher  15  by being engaged with the staple leg portion s 2  in the midst of being formed by the forming plate  11 . 
     Next, the second pusher  16  is arranged to be aligned with a side of a staple strike out port q of the first pusher  15 . Also the second pusher  16  is urged to the face plate  8  by a spring  25 . A front face of the second pusher  16  is formed with a guide portion  21  (second guide face  21 ) capable of being engaged with the rear faces of the legs of the formed staple s, an inner side of a stepped difference  21   a  of the guide portion  21  is continuously formed with an inclined face  26  (second inclined face  26 ) on a side of the supply path  7  and an engaging face  27  (second engaging face  27 ) successive thereto. An end portion of the inclined face  26  is notched and is engaged with the extended portion  20  of the first pusher  15 . It is preferable that the guide portion  21  is also formed such that the guide portion  21   b  is continuously formed with an inclined guide face  21   b  on a side of the supply path  7  and a strike out guide face  21   c  in parallel with the inner face of the face plate  8  as shown in  FIG. 5 . 
     Next, explaining a mode of operating the staple guide mechanism having the above-described constitution, first, when the staple has already been formed in the C-shape, the staple is pushed out to the strike out path  9  by the guide portions  17 ,  21  of the first pusher  15  and the second pusher  16  and pressed to be held by the springs  22 ,  25 . Further, the leg portions s 2  of the staple are held by the guide portions  17 ,  21  of the first pusher  15  and the second pusher  16 . When the drive shaft  12  is operated by a strike mechanism of the stapler main body under the state, the driver plate  10  is driven and therefore, the staple s at the inside of the strike out path  9  is struck out. Although first, the staple s is guided by the guide portion  17  of the first pusher  15 , as shown by  FIG. 7 , when the crown portion s 1  of the staple s is butted to and supported by the inclined face  18  of the first pusher  15 , and is engaged with the engaging face  19 , the first pusher  15  is pushed back against the spring  22  (refer to  FIG. 6 ). Further, successively to the driver plate  10 , also the forming plate  11  is driven and therefore, both sides of a staple at a position next to the struck-out staple s are folded to bend, the folded to bend portion s 1  is engaged with the upper end inclined face  24  of the blade piece  23  to further push back the first pusher  15  to the rear side. Therefore, the staple s in the midst of being struck out loses support. However, the leg portion s 2  of the staple s has already been pressed to and supported by the side of the face plate  8  by the guide portion  21  of the second pusher  16 . Further, also the crown portion s 1  of the staple s is supported by the inclined face  26  of the second pusher  16  and therefore, the staple s is struck out to the binding sheet P in a correct attitude to penetrate therethrough. Thereafter, as shown by  FIG. 8 , also the second pusher  16  is pushed to be remote from the face plate  8  by the forming plate  11 , however, at that occasion, the leg portion s 2  of the staple s is inserted to and supported by the binding sheet P and therefore, the attitude of the staple s does not become unstable and the staple s is firmly penetrated through the binding sheets P. 
     Further, the leg portion s 2  of the staple s is effectively prevented from being folded to bend to the inner side (side of other leg) by a resistance in penetrating through the binding sheet P since the leg portion s 2  is guided by the guide portions  17 ,  21  of the first pusher  15  and the second pusher  16  moved independently from each other. Therefore, the binding operation can further firmly be operated without buckling the leg portion s 2 . Further, when the crown portion s 1  of the staple is struck out, the crown portion s 1  is struck out in a state of being brought into contact with the respective inclined faces  18 ,  26  of the first pusher  15  and the second pusher  16  and therefore, the crown portion s 1  is supported by friction at that occasion and therefore, the crown portion s 1  is not deformed to an M-like shape. In this way, the leg portion s 2  is held by the guide portions  17 ,  21 , the crown portion s 1  is held by the inclined faces  18 ,  26  and therefore, a shape of the bent portion is ensured to be held. 
     When the drive shaft  12  is operated to return after having been operated to bind, also the driver plate  10  is operated to return simultaneously, however, as shown by  FIG. 9 , the forming plate  11  is returned slightly retardedly. When the driver plate  10  is moved to return, first, the second pusher  16  is moved to the side of the face plate  8  by the spring  25  and therefore, the leg portion s 2  of the staple s formed in the C-shape is pressed to be carried to the strike out path  9  by moving the forming plate  11  to an end of movement. Successively, also the first pusher  15  is carried to the strike out path  9  similarly. In this way, the staple s is fed to the strike out path  9  in two stages and therefore, the staple s can firmly be supplied. 
     Further, although in the above-described example, the unformed staple is formed by the forming plate in one motion piece by piece, two or three pieces of the unformed staples may be formed in one motion. 
     Further, the staple cartridge and the forming plate/driver plate may be provided upside down converse to the above-described example. 
     Although the invention has been explained in details and in reference to specific embodiments, it is apparent for the skilled person that the invention can variously be changed and modified without deviating from the spirit and the range of the invention. 
     The application is based on Japanese Patent Application (Japanese Patent Application No. 2004-212339) filed on Jul. 20, 2004 and contents of which are incorporated herein by reference. 
     INDUSTRIAL APPLICABILITY 
     According to one or more embodiments of the invention, when the staple in the C-shape is struck out by the driver plate, the leg portion is struck out by being supported by the first pusher and the second pusher. Meanwhile, also the forming plate is driven successively to the driver plate and therefore, the first pusher is pushed away to be remote from the face plate by the forming plate and therefore, also the staple loses support by that amount. However, at that occasion, the leg portion of the staple has already been pushed to and supported by the side of the face plate by the second pusher and therefore, the staple is struck out to the binding sheet in a correct attitude to penetrate therethrough. Thereafter, although also the second pusher is pushed away to be remote from the face plate by the forming plate, at this occasion, the leg portion of the staple is inserted to and supported by the binding sheet and therefore, the attitude of the staple does not become unstable. Therefore, when the staple is struck out, the staple is guided to be held always in the stable attitude and therefore, when the staple is penetrated through the binding sheet, the staple is not buckled and the smooth and firm binding operation can be carried out. 
     Further, according to one or more embodiments of the invention, the first pusher and the second pusher are formed with portions of guiding the leg portions of the staple and therefore, the leg portion can effectively be prevented from being folded to bend to the inner side (other leg side) by the resistance of penetrating through the binding sheet. Therefore, the binding operation can further firmly be carried out.