Abstract:
A staple storage unit includes return prevention members that prevent a staple positioned for driving from moving back toward the staple storage portion of the staple storage unit. A plurality of staple abutting portions  105   a  and  105   b  are spaced along the draw out direction of the staple band  101  at distances where they do not all abut the staple linking portion  105   d , thereby increasing the likelihood that at least one of the staple abutting portions will engage the staple linking portion to prevent significant withdrawal of the staple sheet back toward the staple storage portion.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a stapler apparatus which binds media (a sheet bundle), such as a plurality of documents printed with a copying machine, a printer, or a composite of machines thereof, etc., with staples, particularly to an improved staple cartridge used in the stapler apparatus. 
     Such stapler apparatuses conventionally are mounted with a staple cartridge comprising a storage portion for storing rolled sheets of rolled bands of staples that are linked to form a sheet, or stacks of sheets of staples. The staple sheets in the staple cartridge are pulled out, and are drawn sequentially to a staple driving position and the staples are then driven into media for binding. 
     Staple cartridges mounted to the stapler apparatus are equipped with a return prevention means to abut the staple linking portion of the stable band drawn out with a return stopper pawl so that the staple band pulled out from the storage portion does not return back into the storage portion. 
     However, the return stopper pawl of the return prevention means abuts the staple linking portion on one location with the paired left and right pawl or to increase the abutting force thereof, a return stopper pawl is disposed in front and back in the direction of staple band pull-out disposed to abut the staple linking portion on two locations with the paired left and right pawl simultaneously. 
     However, there are situations where the staple linking portion cannot be securely abutted to stop because of variations in the width dimensions of the staples or the gap of the staples that configure the staple band, caused by the adhesive, or the variations in the staple cartridge mounting position, the variations in the gap in the staple linking portion that is abutted by the return stopper pawl from the staple that has been drawn to the driving position, the variation thereof causing the return stopper pawl to ride up on the surface of the staple. 
     In the state where the return stopper pawl rides up on the surface of the staple, the staple band backs up an amount near the width of the staple, at its maximum to move to be abutted. This results in the staple that had already been drawn to the driving position returning back and causing a discrepancy in its position. This is one of the causes of the binding problems of the mis-driving or biting of staples. 
     SUMMARY OF THE INVENTION 
     An objective of the invention, in view of the aforementioned problems, is to provide a staple cartridge that can arrest staple mis-positioning with regard to the driving position within a tolerance range that arrests stapler apparatus binding problems even if there is a variation in the staple gaps caused by staple width dimensions or adhesive or the return stopper pawl riding onto the surface of the staple. 
     The invention includes a staple cartridge comprising a staple band linking staples in a sheet shape, a storage portion to store the staple band, and a return stopper means that abuts staples at the staple linking portion to prevent staples linked together in a staple band drawn from the staple storage portion from returning to the staple storage portion, the aforementioned return stopper means comprise a plurality of staple abutting portions, the plurality of staple abutting portions are disposed front and back along the direction of the draw out of the staple band and in gaps where they do not abut the aforementioned staple linking portion simultaneously. 
     According to one aspect of the invention, one of the plurality of abutting portions disposed front and back along the direction of draw out of the staple band increases the probability to abut the staple linking portion. Also, in the worst case, if all of the stopper portions ride up onto the surface of the staples, it is simple to hold that down by setting a number of stopper portions to within a tolerance range without causing mis-positioning corresponding to the surface of the staple as in the past. 
     According to another aspect of the invention, the plurality of stopper portions of the return prevention means is composed of the quantity of M, and when the width dimension in the direction of staple draw out is set to Lmm, each stopper portion is arranged front and back in the direction of draw out and the gap of the stopper portions positioned front and back is set to L/Mmm. 
     According to another aspect of this invention, the L/Mmm gap for the plurality of stopper portions for the return prevention means provides an optimum positional relationship. 
     According to another aspect of the invention, the plurality of stopper portions of the return prevention means is composed of the quantity of M, and when the width dimension in the direction of staple draw out is set to Lmm, each stopper portion is arranged front and back in the direction of draw out and the gap of the stopper portions positioned front and back is set to a value that adds L/Mmm to nL/Mmm (where n is a natural number). 
     According to another aspect of this invention, the stoppers in a plurality of locations are disposed with the optimum positional relationship, such that each of the stopper portions is arranged to span a plurality of staples. 
     The invention further provides a staple cartridge comprising a staple band linking staples in a sheet shape, a storage portion to store the staple band, and a return stopper means that abuts staples at the staple linking portion to prevent staples linked together in a staple band drawn from the staple storage portion from returning to the staple storage portion. The aforementioned return stopper means comprise a plurality of staple abutting portions, the plurality of staple abutting portions are disposed front and back along the direction of the draw out of the staple band and in gaps where they do not abut the aforementioned staple linking portion simultaneously. 
     Below, an embodiment of the stapler apparatus according to the present invention will be described in accordance with the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view comprising a sectional view of a stapler device mounted with the staple cartridge according to the embodiment of the instant invention. 
         FIG. 2  is a plan view of the disassembled units of the stapler device mounted with the staple cartridge according to the embodiment of the instant invention. 
         FIG. 3  is an expanded explanatory view depicting the abutting of the staple band by the return stopper pawl in the staple cartridge according to the invention. 
         FIG. 4  is an expanded explanatory view depicting the abutting of the staple band by the return stopper pawl in the staple cartridge of another embodiment of the invention. 
         FIG. 5  is an expanded explanatory view depicting the abutting of the staple band by the return stopper pawl in the staple cartridge according to another embodiment of the invention. 
         FIG. 6  is a timing chart of the operations of the stapler apparatus according to the embodiment of the instant invention. 
     
    
    
     DESCRIPTION OF THE REFERENCE NUMERALS 
     
         
           100  Staple cartridge 
           101  Staple band material 
           101   a  Staple adhesive tape 
           102  Staple storage portion 
           105  Return stopper pawl member (return prevention means) 
           105   a  Return stopper pawl (staple abutting portion) 
           105   b  Return stopper pawl (staple abutting portion) 
           105   c  Return stopper pawl (staple abutting portion) 
           105   d  Staple linking portion 
           200  Cartridge holder 
           300  Stapler unit 
       
    
     DETAILED DESCRIPTION 
       FIG. 1  is an external perspective view showing a section of part of the entire stapler apparatus, mainly comprising the staple cartridge  100 , the cartridge holder  200  and the stapler unit  300 . 
     Firstly, to describe the apparatus according to the sequence of its assembly, the stapler unit  300  comprises the unit frame  310 , the electric drive unit, not shown in the figures, the staple head unit  330 , the actuating lever  340 , the anvil unit  350 , the clincher unit  360 , the interlock lever  370 , the anvil spring  380 , the paper thickness absorbing spring  390 , the clincher spring  400  and the manual drive plate  500 . 
     The unit frame  310  is sheet metal formed into a sectional U-shape comprising sides established left, right and a bottom. It internally holds the electric drive unit, thereabove the holder guide  301 , which is shown in  FIG. 2  and the staple head unit  330  in the leading edge and properly supports other units on the outside side walls thereof. 
     Note that the electric drive unit, which is not shown in the figures, is composed of a direct current motor that is the stapler drive source, the gear train that decelerates the rotation of the motor to a determined rotating speed and the transmission cams that are decelerated to the determined speed and rotate. Each transmission cam drives the staple head unit  330  and the anvil unit  350  via the actuating lever  340  and the interlock lever  370  and by driving the clincher unit  360  it controls the series of operations of the stapler. 
     The staple head unit  330  comprises the sheet loading table  331 , the driver  332 , the former  333 , the sheath  334  and the bending block  335 . 
     Furthermore, the staple head unit  330  starts the upward direction displacement of the driver  332  formed with a leaf spring material by the driver drive cam pin disposed on the last level of the electric drive unit. 
     Displacement of the driver  332  abuts the former abutting piece  332   a  on the driver  332  against the former  333 . The driver  332  and former  333  follow a stepped surface, not shown in the figures, formed on the sheath  334  upward to a position where that abutment is released. 
     The former  333  bends into a U-shape staples drawn to the staple bending position of the bending block bending block  335  and holds to guide U-shaped staples on the sides of the former  333  thereof to enable driving. Note that the position where the staple is bent by the former  333  corresponds to the staple driving position below. 
     In this state, the driver  332  released from abutting the former  333  by the protrusion, not shown in the figures, formed at the sheath  334  is displaced further upward leaving the former  333  in that position. 
     By displacing upward, the staple driving unit  332   b  positioned at the leading edge of the driver  332  displaces the bending block  335  to the front from the region of movement of the driver  332  and retracts. 
     The staple driving unit  332   b  of the driver  332  displaced further upward separates from the adhesive staples that have been bent and are adhering to the next staple by adhesive tape. Formed and separated staples are driven into the binding media. 
     Next, the actuating lever  340  has arms extending left and right along the side surfaces of the anvil unit  350 . While nipping in the unit frame  310 , they are supported by the interlocking pivot shaft  331  disposed on the anvil unit  350  sides. 
     In addition, the paper thickness absorbing springs  390  are stretched between the anvil unit  350  in a central location on the left and right arms of the actuating lever  340 . These springs  390  constantly urge in the counterclockwise direction around the interlocking pivot shaft  331  to contact with the stopper  351  formed on the anvil unit  350 . 
     The notch  341  comprising an edge to abut with the anvil drive lever, which is not shown in the figures, driven to displacement by the electric drive unit, is formed on the leading edge of the arm positioned on the other edge of the left and right arms. The anvil drive lever swings it clockwise around the interlocking pivot shaft  331  which is pressed and urged downward. 
     The anvil unit  350 , the anvil rocking pivot  352  on one side thereof rockingly supported on the pivot shaft  312  on the unit frame  310 , is constantly rotatingly urged in the clockwise direction by the anvil spring  380  around the pivot shaft  312 . 
     The anvil head  353  on the other side follows the rocking of the actuating lever  340  and rocks counter-clockwise resisting the urging force of the anvil spring  380  to nip and support the binding media at a position that corresponds to the thickness thereof. 
     Note that after the anvil unit  350  nips and supports the binding media by the paper thickness absorbing springs  390 , the actuating lever  340  continues acting alone in resistance to the resilient force of the paper thickness absorbing springs  390  because the anvil unit  350  is locked in that nipping position. 
     To the anvil head  353  that nips the binding media on the anvil unit  350 , the clincher unit  360  that has the left and right paired clinchers  354  for bending the leading edges of staples that have penetrated the binding media driven from below the binding media, is disposed to follow. 
     The clincher unit  360  comprises the clincher lever  361  and is supported by the pivot shaft  312  on the unit frame  310  which is also the pivot for the anvil rocking pivot  352  on the anvil unit  350 . To the leading edge of the clincher unit  360  is mounted the clincher head  362  that bends staples that have been driven and rocks the clincher  354  mounted to the anvil head  353  on the anvil unit  350 . 
     The clincher head  362  is press formed using a steel plate for a spring with a thickness of 1.5 mm while the clincher lever  361  is formed using a plated steel plate of a thickness of 2.0 mm, to absorb the difference in pressing stroke of the clincher  354 . 
     Next, the interlock lever  370  follows the rocking of the anvil unit  350  via the clincher spring  400  to rock the clincher unit  360  and is disposed to continue rotating with the rocking of the clincher drive lever, not shown in the drawings, while the anvil unit  350  nips and stops the binding media. After the anvil unit  350  stops at the nipping position that corresponds to the thickness of the binding media, it continues rotating to bend the staples. 
     The manual drive plate  500  is for resetting stapling defects by manually operating the stapler when a staple is not properly driven into the binding media and the defective staple prevents the stapler apparatus from operating, and thus causes a stapling problem when driving staples. The drive plate  500  is mated to the rotating shaft extending to the back side of the output shaft of the direct current motor of the electric drive unit, which is not shown, when manual operations are necessary. 
       FIG. 2  is an exploded perspective view showing the cartridge holder  200  and staple cartridge  100  that are mounted on the stapler unit  300  in  FIG. 1  pulled out. 
     When pulling from the stapler unit  300 , first the cartridge lock lever  600  which abuts the staple cartridge  100  and urgingly supports in the mounting direction is manually pressed downward to release the abutting, then the staple cartridge  100  is pulled from the cartridge holder  200 . 
     Then, the cartridge holder  200  is pulled from the stapler unit  300 . Conversely, it is also possible to remove the staple cartridge  100  from the cartridge holder  200  after pulling out the cartridge holder  200  while the staple cartridge  100  is mounted to the cartridge holder  200 . 
     Note that the reverse procedures are acceptable when mounting the staple cartridge  100  and cartridge holder  200  to the stapler unit  300 . 
     The staple cartridge  100  is composed of a semi-transparent plastic case and comprises the storage unit  102  that stores the staple band material  101  into which sheets of a plurality of straight staples linked into a band are wrapped into a roll, and the pull-out guide  103  for pulling out the staple band material  101 . 
     The pull-out guide  103  is mounted to the cartridge holder  200  and is equipped with the opening  104  the guide surface on the leading top side being widely cut away to abut the staple feed means  202  on the cartridge holder  200 , the back-feed stopper pawl  105  to arrest so that the staple band material  101  pulled out from the storage unit  102  does not return back into the storage unit  102 , and the leading edge stopper  106  that restricts the leading edge of the staple band material  101  that has been pulled out and that positions the leading edge thereof at the binding position while mounted to the stapler unit  300 . 
     Also, it comprises the feed pawl advancing protrusion  107  that protrudes into the guide surface on the top-side of the leading edge formed on the opening  104  on the pull-out guide  103  and advances the staple feed means  202  when mounting to the cartridge holder  200  to press the leading edge of staples in the staple band material  101  to the edge stopper  106 . 
     Furthermore, to both sides of the staple cartridge  100  are equipped the guide protrusion  108  guided when mounting to the cartridge holder  200  and the stopper pawl  109  stopped when mounting to the cartridge holder cartridge holder  200 . 
     Though not shown in the figures, it is possible to bend open the bottom portion of the staple cartridge  100  from an appropriate position on the back-feed stopper pawl  105  and the edge stopper  106  to the storage unit  102 . By opening, the back-feed stopper pawl  105  is released from stopping the staple band material  101  thereby making it possible to discard all remaining staples when discarding. 
     The cartridge holder  200  is composed of the holder unit  201 , the staple feed means  202 , the magnet  203 , the guide plate  204  comprising a non-magnetic body, the opening  205 , the guide  206 , the abutting hole  207  and the auxiliary table  208 . 
     The holder unit  201  is formed of a plastic material to cover the front half of the staple cartridge  100 . 
     The staple feed means  202  is rockingly supported on the holder unit  201  and is constantly urged to the staple pull-out direction by a leaf spring, which is not shown in the figures. It is interlocked to the nipping action of the binding means by the anvil unit  350  and charged. It comprises a feed pawl for pressing the staple sheet surface of the staple band material  101  with the recovery action caused by the release of the charge to advance the staple band material  101 . 
     The magnet  203  and the guide plate  204  faces the staple to be driven at the binding position when mounted to the stapler unit  300  and the magnetic attraction of the magnet attracts mis-driven staples to discharge them outside from the stapler unit  300 . 
     The opening  205  is for setting the leading edge of the stopper  106  on the staple cartridge  100  and the leading edge of the staple to protrude and be set at the binding position 
     The guide  206  is for guiding the guide protrusion  108  on the staple cartridge  100  and is composed of a cut-out groove and a bottom surface. 
     The abutting hole  207  abuts the stopper pawl  108  on the staple cartridge  100  and it is one of the supplementary stopping means on the staple cartridge  100  until the staple cartridge  100  is locked by the cartridge lock lever  600 . 
     The supplementary table  208  acts as the loading table where the binding media is loaded along with the table  331  on the staple head unit  330 , as shown in  FIG. 1 , when mounted to the stapler unit  300 . 
       FIG. 3  shows the return stopper pawl  105  (the return prevention means) on the staple cartridge  100  abutting the staple linking portion  105   d  on the staple band  101 . This return stopper pawl  105  is positioned so that it avoids the adhesive tape  101   a  that glues the staples on the staple band  101  to each other and are arranged symmetrically left and right so that the staple band  101  can be drawn out parallel, and the return stopper pawl portions (staple stopper portions)  105   a  and  105   b  are formed at the positions abutting the staple linking portion  105   d  on the staple band  101  in positions offset along the width of the staple. In this case, at the maximum, the amount offset on the staple band  101  can be held to within the width dimension of the width of the staple on the staple band  101  separated into two parts. 
     Note that after a 0.2 mm thick plate is press formed to a spring member for the return stopper pawl  105 , the return stopper pawl  105   a  and  105   b  are bent to according to the inclination. Also, the amount of discrepancy of the return stopper pawl  105   a  and  105   b  is 0.2 mm to 0.25 mm as a guide for bending, equivalent to approximately half of the width of the staple at 0.4 mm to 0.5 mm. Furthermore, the shape, angle of their bending or the position of their bending for the return stopper pawl  105   a  and  105   b  is changed appropriately according to the staple band  101  so that there is no variation in their abutting performance. 
     Also, the structure arranges the return stopper pawl  105  to the back side on the staple tape  101   a  and the staple band  101  but because there is no need to avoid the staple tape  101   a , the return stopper pawl  105  can be arranged in symmetrical positions left and right thereof to allow the parallel pull out of the staple band  101 . 
       FIG. 4  and  FIG. 5  show another embodiment of an abutting method of the return stopper pawl for the staple band  101  on the staple cartridge  100 . 
       FIG. 4  shows the 3 portions of the return stopper pawl portions (staple abutting portions)  105   a ,  105   b  and  105   c  on the return stopper pawl  105  (return prevention means) arranged front and back in the direction of staple band  101  draw out and abutting the staple linking portion  105   d  on the staple band  101 . Each of these are formed to have three equal gaps in the width of the staple. In this case, it is possible to arrest the amount of offset of the staple band  101  within three equal parts of the staple band  101  width in the width dimension. 
     Note that the aforementioned embodiment shows two return stopper portions of  105   a  and  105   b  and three portions of  105   a ,  105   b  and  105   c . However, generally, with the return stopper pawl portion of M and the width dimension in the direction of drawing out the staple set to Lmm, it is acceptable to arrange each of the stopper pawls front and back in the direction of staple draw-out with the gap of L/Mmm. 
     Also, it is acceptable to set the appropriate gaps if it is not possible to form stopper pawl portions in equal gaps on opposite surfaces of staples that have enough space. In such case, the amount of offset of the staple band  101  is dependent upon the maximum gap. 
       FIG. 5  shows return stopper pawl (return prevention means)  105 , the return stopper pawl portion (staple abutting portion) composed of the single pawl  105   a  arranged front and back in the direction of draw out of the staple band  101  and abutting the staple linking portion  105   d  on the staple band  101 , being arranged in a position adding half of the staple width to the n part of the staple width. In this case, the amount of offset of the staple band  101  is half of the width of the staple band  101 , if there is no difference in the dimension of the staple width. 
     Note that the gap of the plurality of return stopper pawl portions on the return stopper pawl  105  can be arranged in different gap positions that are not n portions of the staple width. In such case, the amount of offset of the staple band  101  is maximum width of the gap of the plurality of return stopper pawl portions. Also, n is a natural number including 0. 
       FIG. 6  is a timing chart to illustrate the operation of each of the driver, former, anvil and clincher units&#39; processes. The horizontal axis indicates the angle of rotation of the drive cam that drives each unit and the vertical axis shows the amount of displacement of the levers for each unit. The following generally describes the series of actions according to  FIG. 1 . 
     Initially, along with the setting to the stapling position of the binding media a staple execution instruction signal is output to the stapler apparatus from an outside source. 
     The instruction signal starts the rotation of the direct current motor in the electric drive unit, which is not shown in the drawings, first pushing the actuating lever  340  in the downward direction by the anvil drive cam, which is not shown in the drawings, resisting the anvil spring  380 . 
     Following the displacement of the actuating lever  340 , the anvil unit  350  moves downward to start nipping the binding media. 
     Note that, interlocked to the nipping of the anvil unit  350 , the clincher unit  360  interlocked by the interlock lever  370  and the clincher spring  400  follows the anvil unit  350 . 
     In describing the operation of the anvil unit  360 , beginning from the idling position A 0 , rocking stops at a nipped position according to the thickness (the number of sheets) of the binding media set at the binding position, between the position A 1  where, for example, 100 pages of binding media are nipped to the position A 2  where 0 pages are nipped of binding media. 
     After nipping the binding media by the anvil unit  360 , only the actuating lever  340  continues displacement resisting the paper thickness absorbing springs  390 . The anvil unit  360  maintains a displaced state to the position equivalent to the position A 3  by applying an over-stroke to the position A 2  to enable the secure nipping even if there are 0 pages of binding media, in consideration of variations in parts and their assembly, to complete the nipping operation of the binding media using the anvil unit  360 . 
     Before operating to the position A 3  to complete the nipping operation of the binding media using the anvil unit  360 , the driver drive cam CA 40 , shown in  FIG. 4  displaces the driver  332 , which is not shown in the drawing, upward, and the former  333  following this displacement is pressed upward. 
     The driver  332  begins moving from the position D 1  when the clincher unit  360  is beyond the position A 1 , at position D 2 , the former  333  presses the staple drawing to the driving position and starts forming the staple into a U-shape. In the continuing stroke, by pushing both leading edges of bent staples formed into that shape against the sides of the bending block  335  to guide it, both leading edges of the staple are secured front, back left and right by the non-magnetic materials of the guide plate  204  walls composed of the former  333 , the bending block  335  and the cartridge holder  200 . 
     Then, the leading edges that touch the formed staple of the driver  332  are pressed into the oblique surfaces of the bending block  335 . The leading edge portion of the driver  332  touches the formed staple at the position D 3  with the bending block  335  retracted from the area of movement of the leading edge of the driver  332 . The leading edge of the formed staple pressed by the driver  332  delayed from the position A 3  where the anvil  350  nips the binding media reaches the position D 4  that touches the surface of the sheet of the binding media to start driving the formed staple into the binding media by the driver  332 . 
     After the driver  332  starts driving the staple, at the same time that the abutting portion that was abutting the former  333  on the driver  332  is released from abutting, by the level protrusion on the sheath  334  at the slightly delayed position D 5 , the former  333  is released from abutting with the driver  332  at the position D 6  just prior to the leading edge of the former  333  touching the surface of the sheets in the binding media and the former  333  stops and the former guides the bend staple driven by the driver  332 . 
     Continuing on, the formed staple is driven by the driver  332 , and after the formed staple crown touches the surface of the sheets in the binding media at the position D 7 , the driver  332  is further driven by the driver drive cam at the position D 8 , but because the driver  332  cannot press the formed staples in, the driver  332  comprising a leaf spring, itself is elastically deformed the amount of the over-stroke to absorb the difference of the mounting position to securely drive the formed staple. 
     The clincher unit  360  is rocked by the clincher drive unit  602  pressed downward by the clincher drive cam CA 10  shown in  FIG. 11  from position C 1  immediately after the position D 8  where the formed staple is driven by the driver  332 , pressing the clincher  354  to complete the clinching operation at the position C 2  by bending the leading edges of the staples that have penetrated the binding media. 
     After the clinching operation is completed, first, the recovery operation is started for the driver  332  at the position D 11 . The former  333  part way is re-interlocked and returned to the position D 0  which is equivalent to the initial position passing through the positions of D 12  and D 13 . 
     The anvil unit  350  recovery operation is started slightly delayed to the recovery operation of the driver  332  and is returned to the position A 7  which is equivalent to the initial position passing through the position A 6 . 
     Finally, the anvil unit  360  recovery operation is started slightly delayed to the recovery operation of the driver  350  and is returned to the position C 4  which is equivalent to the initial position to complete the series of the staple operation.