Abstract:
Apparatus for removing fasteners ( 13; 63; 113; 163 ) from documents ( 12; 62; 112; 162 ) with a perforator ( 5; 55; 105; 155; 205 ) for perforating documents ( 12; 62; 112; 162 ) in the area of the fastener to be removed, wherein the means for separating from the set of documents ( 12; 62; 112; 162 ) the fastener to be removed ( 13; 63; 113; 163 ) are constructed as a perforator for perforating the set of documents closely along the fastener to be removed. Also disclosed is a method for removing fasteners ( 13; 63; 113; 163 ), wherein the fastener ( 13; 63; 113; 163 ) is separated from the documents ( 12; 62; 112; 162 ) simply and fast in a single operation by perforating the set of documents ( 12; 62; 112; 162 ) closely along the fastener to be removed ( 13; 63; 113; 163 ).

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     This invention relates to an apparatus and a method for removing fasteners from sets of documents. 
     Such an apparatus and such a method are known from U.S. Pat. No. 4,090,690. 
     It is noted that fasteners to be removed occur in a large variety, as in the form of staples with a bridge part and two bent legs, eyelets, metal plates which are bent over a corner of a document, and split pins which, in fitted condition, have a button resting against the set of documents. 
     The apparatus and method according to U.S. Pat. No. 4,090,690 constitute an improvement over the destaplers known heretofore, especially for rapidly removing large numbers of staples, because the laborious hooking of the fastener and then pulling it away relative to the documents have been replaced by a single operation, whereby at least a portion of the staple is pressed into the set of documents. 
     However, a drawback of this known destapler is that a staple, after it has been pressed into the set of documents, must still be separated from the documents. A further drawback of this known destapler, and the method to be practiced with it, is that the staples cannot be pressed through sets of documents of a thickness more than twice the wire thickness of the staple. Further, in many cases, the fastener tilts during compression, so that the maximum thickness of a set of documents through which a staple can be pressed is limited to a set of documents having a compressed thickness less than a single time the wire thickness of a fastener. 
     SUMMARY OF THE INVENTION 
     The object of the invention to provide a solution to the problem of removing fasteners very fast and reliably from sets of documents. 
     According to the present invention, this object is realized by providing an apparatus for removing fasteners from sets of documents, which comprises a perforator for perforating a set of documents closely along at least a portion of a fastener to be removed. A further embodiment of the invention for realizing this object is formed by a method for removing fasteners from sets of documents, wherein the set of documents is perforated along at least a portion of the fastener to be removed. 
     By perforating the set of documents from which the fastener is to be removed, a passage right through the set of documents is created in a simple and reliable manner, so that the fastener can be simply removed. The perforation provided in the set of documents when removing the staple may be of a very minor size and does not constitute any essentially greater damage of the documents than the weakening of the documents and the creases and dog-ears formed in the conventional removal of fasteners. Generally, next to the perforation, sufficient space is left for fastening the documents to each other again, if desired. In general, it is advantageous if the perforation extends as closely as possible alongside the staple. Perforating directly alongside the staple is most ideal, but it is also possible to select distances between the position of this fastener to be removed and the most proximal edge portion of the perforation to be less than 1, 2, 3 mm or slightly more. 
     Hereinafter, further objects, embodiments, effects and advantages of the invention are described and explained on the basis of a presently most preferred exemplary embodiment and a few variants, with reference to the drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of a destapler according to the invention; 
     FIG. 2 is a cut-off, perspective representation of a punch-die plate combination for use in an apparatus according to FIG. 1; 
     FIG. 3 is a sectional side elevation of the punch-die plate combination according to FIG. 2; 
     FIG. 4 is a cut-off top plan view of a punch of a destapler according to a further exemplary embodiment in a condition of use above a staple in a set of documents; 
     FIG. 5 is a sectional side elevation along the line V-V in FIG. 4; 
     FIG. 6 is a sectional side elevation along the line VI-VI in FIG. 4, albeit that the punch is shown in a condition pressed through the set of documents; 
     FIG. 7 is a sectional cut-off side elevation of a destapler according to a still further exemplary embodiment in a condition of use just before the perforation of a set of documents; 
     FIG. 8 is an elevation similar to FIG. 7, in a condition of use in which the set of documents has just been perforated; 
     FIG. 9 is a sectional cut-off side elevation transverse to the elevation according to FIG. 8; 
     FIG. 10 is a sectional cut-off side elevation of a destapler according to a yet further exemplary embodiment in a condition of use just before the perforation of a set of documents; 
     FIG. 11 is a schematic representation of a sensor for detecting the position and the orientation of a staple; and 
     FIG. 12 is a cutaway side elevation of a destapler with automatic positioning of the destapling perforator. 
    
    
     DETAILED DESCRIPTION 
     The following description is based on examples intended for removing staples consisting of wire material forming a bridge part and bent legs, projecting from that bridge part. However, it will be clear to those skilled in the art that adapted embodiments can also be used for removing other types of permanent fasteners provided through documents or embracing them. 
     FIG. 1 shows, by way of example, a stapler based on a commercially available stapler of the make Rapid, type “2”, manufactured by Isaberg AB of Hestra, Sweden, with an underframe  1 , a reciprocable supporting arm  2  which can be pivoted back and forth relative to the underframe  1  about an axis  3 . Naturally, as a basic structure, any other stapler or a specially constructed stapling machine having a sufficiently stable construction can be used. 
     In a manner which is known and therefore not further described here, the supporting arm  2  is provided with a mechanism  4  for providing staples through sets of documents. 
     The apparatus further comprises a perforator  5  with a die or punch  6  and a die plate  7 . The supporting arm  2  further carries a punch member  6  of perforator  5  and the underframe  1  carries the die plate member of the perforator  5 . 
     The mechanism  4  for providing staples has an operating knob  8  which is mounted on a transmission slide  9 . In conventional use, upon depression of the operating knob  8 , the slide  9  is moved down and a staple is shifted off a row of staples and pressed into a set of documents which is held between the supporting arm  2  and the underframe  1 . To block the transmission slide  9  in its upper position, the mechanism  4  for providing staples comprises a blocking pawl  10  which is operable by a sliding knob  11 . When the sliding knob  11  is in the “STAPLE” position, the transmission slide  9  is released, allowing it to reciprocate in a conventional manner for providing staples. When the sliding knob  11  is in the “DESTAPLE” position, the transmission slide  9  is blocked, allowing the operating knob  8  to be pressed upon for perforating (piercing) paper in the area of a staple without the stapling mechanism  4  dispensing and placing a new staple. 
     The construction and the operation of the perforator is described in more detail with reference to FIGS. 2 and 3, which represent the embodiment of perforator  5  that is presently preferred most. 
     In FIG. 3, the perforator  5  is represented with a set of documents  12 , fastened to each other by a staple  13 , placed between the punch  6  and the die plate  7 . The punch  6  forms a projection for perforating the set of documents  12  and, as the set of documents is being perforated, for engaging, through the perforation provided, the staple  13  to be removed, which is thereby pressed, ahead of the punch  6 , through the Set of documents  12 . 
     More particularly, starting from the situation shown in FIG. 3, first the punch  6  is moved down, causing the set of documents  12  to be perforated and portions of the documents in which the staple  13  is provided to be cut loose from surrounding material. In the process, the staple  13  and any adjacent material of the set of documents  12  are temporarily received in a recess  14  in the punch  6 , while a schematically indicated resilient element  15  engages the staple and thereby exerts a pressure force on the staple  13  in the direction of movement of the punch  6 . As soon as the perforation of the set of documents  12  is complete and the staple  13  has been cut loose completely from the documents  12 , the staple  13  is ejected by the resilient element  15  through an opening  16  in the die plate  7  and a portion  17  of the subjacent underframe  1 . 
     It is also possible to make the recess  14  in the punch  6  considerably less deep, for instance just deep enough to keep the staple  13  in front of the punch  6 . In that case, during the perforation of the set of documents  12 , the staple is pressed ahead of the punch  6 , which requires a higher punching force but enables a simple construction of the punch and limits the risk of the staple getting stuck in the recess in the punch. 
     The die plate  7  has an elongate opening for receiving and passing a staple to be removed. This provides the advantage that the staple can be punched loose and separated in a single movement. It is also possible, however, to have a punch run against a counterplate and, for instance, to eject the staple by moving the punch together with the set of documents away from the counterplate. 
     The opening  16  in the die plate  7 , located opposite the punch  6 , further facilitates accurate positioning of the staple  13 , in that the opening  16  in the die plate  7  further functions as a positioning recess into which falls the staple portion remote from the punch, projecting from the set of documents  12 . When positioning the set of documents  12 , it is thus clearly felt whether or not the staple  13  is properly positioned. Furthermore, arresting the staple in the opening  16  facilitates keeping the staple  13  exactly in its position opposite the punch  6  during punching. 
     For an accurate positioning of the staple  13 , it is further advantageous that the opening  16  in the die plate  7  is shaped to correspond with the cross section of the punch  6 . If the portion of the staple  13  remote from the punch  6 , projecting outside the documents  12 , falls into the opening  16 , the staple is thus reliably positioned in the punching path of the punch  6  at all times. 
     FIGS. 4-6 represent an alternative embodiment of a perforator  55  for a destapler according to the invention, each time in combination with a set of documents  62  and a staple  63  to be removed therefrom. The perforator  55  has a punch  56  and a die plate  57  with an opening  66 . The punch  56  has an end face  68  which forms a profile in the form of a channel-shaped recess, traversing the end face, for receiving a portion of a staple  63 . A central portion  69  of the opening  66  of the die plate  57  corresponds to the shape of the cross section of the punch  56 . Peripheral portions  70  of the opening  66  of the die plate  57  on opposite sides of the central portion  69  are open when the punch  66  is in a position projecting into the die plate  57 . Other profiles, such as a serration or a pair of projecting parts, may also be used to keep the staple opposite the end face during removal. 
     In the use of such a perforator  55 , the perforation is provided by the punch  56  between arms  71  of the staple  63 . Each time the punch  56  has been pressed through the set of documents  62 , the punch  56  engages a bridge portion  72  of the staple  63 . This stage of the process of removing a staple is shown in FIG.  6 . Finally, the punch  56  presses the staple  63  out of the set of documents  62 , causing the arms  71  to bend slightly to a position transverse to the plane in which the set of documents  62  extends. The channel-shaped recess extending transversely across the end face of the punch  56  here ensures that the bridge portion  72  of the staple  63 , as it is being pressed away, remains opposite the punch  56  and does not slide laterally off the end face of the punch  56 . A particular advantage of this perforator is that it does not need to be oriented relative to the staple to be removed, at least when the opening in the die plate allows the passage of staples regardless of the orientation in the plane of the set of documents. 
     Since the central portion  69  of the opening  66  in the die plate  67  is wider than the peripheral portions  70  of that opening  66 , a punch  56  can be used which is wider than the staple  63 , while the staple  63 , owing to the narrow peripheral portion  70 , is accurately centered, especially in its transverse direction, relative to the punch  56 , and the punch  56  reliably engages centrally of the staple  63 . Further, the narrow design of the outer portions  70  of the opening  66  limits bulging of the documents. 
     FIGS. 7-9 represent another alternative embodiment of the perforator  105 . This perforator  105  is provided with knives  123  for cutting through a set of documents  112  along a staple  113  to be removed. By cutting along a staple  113  to be removed, and removing the cut-loose staple  113  from the set of documents  112 , the amount of material that is removed from the documents  112  is kept very low. If cutting is limited to a single cut along the staple, the amount of cut-loose material can even be limited to substantially zero. 
     According to the present example, however, two knives  123  are used, which are suspended to cut on opposite sides along a staple  113  to be removed. Thus, the staple  113  can be cut loose highly reliably. 
     The knives  123  are suspended so as to converge in a cutting direction (arrow  124 ), causing them, during cutting, to push towards the staple  113  and slide along the staple  113 . As a result, cutting proceeds very closely along the staple  113  and cuts are obtained which, practically speaking, communicate with the holes provided in the set of documents  112  when the staple  113  was applied, so that the staple  113  is cut loose completely, or substantially completely, from the set of documents  112 . 
     The knives  123  have fixed ends  125  which are suspended so as to be movable relative to each other, transversely to the cutting direction  124  and the cutting edges  126 . To that end, a knife holder member  127  which is reciprocable along with the knives  123  in the cutting direction  124 , is provided with a slot  128 , transverse to the cutting direction, in which slot guide slides  129  carrying the fixed ends  125  of the knives  123  can be reciprocated. Due to the displaceability of the fixed ends, the angle between the knives  123  can be gradually reduced during the movement in the cutting direction  124 , so that, even when perforating thicker packs of documents  112 , the distance between the cuts on the side of the packs of documents  112  proximal to the knives  123  is limited, and tearing of the documents between the cuts is prevented. 
     The guide slides  129  are further guided in slots  130  in a fixed portion  131  of the knife holder. These slots  130  converge in the shape of a V in the cutting direction  124 , so that during the performance of a perforation stroke, an imposed movement of the fixed ends  125  of the knives is obtained, with the mutual distance between them decreasing according as the knives  123  move further in the cutting direction  124 . As a result, the knives  123  always move substantially in the direction in which they project, so that tearing of documents is prevented. 
     For limiting damage to the set of documents  112 , it is further advantageous that the knives  123  are of flexible design, so that they can adjust to the documents  112 . This further provides the advantage that the knives  123 , from the fixed ends  125 , can be pressed obliquely against a side of a staple  113 , but alongside the staple  113  can extend virtually parallel to the legs of the staple. This enables reliably making cuts that extend very closely along the staple throughout their height. 
     As appears from FIG. 9, the cutting edges  126  each have a central portion  132  and outer portions  133 , the central portion  132  projecting relative to the outer portions  133  in the cutting direction  124 . Such a design of the cutting edge  126  limits the cutting forces. In combination with the position of the knives  123  projecting obliquely towards the staple  113 , this design of the cutting edge  126  further makes it possible for the central portion  132  of the cutting edge  126  to cut inside the space enclosed by the staple  113 , while the outer portions  133  of the cutting edge  126  are guided by the legs of the staple  113 , extending through the documents  112 . 
     Optionally, it is possible to further use the central portion  132  of the cutting edge  126 , while engaging the bridge portion  124  of the staple  113 , to press the staple from the documents  112 . However, for displacing the staple  113 , it is preferred to use stop surfaces  135  facing in the cutting direction  124  for carrying along a staple  113  to be removed. This prevents contact between the cutting edge  126  and the typically steel staple  113 , so that the cutting edge  126  remains sharp longer. 
     According to the example shown, the stop surfaces  135  of the knives  123  engage the portions of the staple  113  that are proximal to the knives  123  prior to cutting. It is also possible, however, to arrange for such stop surfaces carried by the knives to engage another portion of the staple, such as the bridge portion. 
     In the perforator  105  according to this example, too, the documents  112  are supported in the area of the staple  113  by a die plate  107  with an opening  116 , through which opening  116  the staple  113  passes after being separated from the documents  112 . 
     FIG. 10 shows a still further exemplary embodiment of the perforator  155  for perforating a set of documents to remove a staple therefrom. The perforator  155  has two punches  156  of a cross section slightly greater than the cross section of the wire material of which the staples to be removed consist. Located opposite the punch dies  156  is a die plate  157  with an opening  166 , in which the dies  156  fit with a very minor lateral clearance, and through which fit portions of the staple  163 . The punch dies  156  are represented in solid lines in a position immediately prior to the cutting of the staple and the perforation of the set of documents  162 . Broken lines indicate the punch dies  156  in an extreme projecting position. To remove a staple  163 , the punch dies  156  are displaced from the starting position in the cutting direction towards the extreme projecting position. This causes the staple to be cut first adjacent two corner points between portions extending through the set of documents and portions extending along the set of documents. Then, two cut-loose portions of the staple  163 , including the portions extending through the set of documents, are pressed away, ahead of the punch dies  156 , out of the set of documents  162 , while the punch dies  156  perforate the set of documents  162 . These cut-loose portions leave the set of documents  162  through-the opening  166  in the die plate  157 . 
     Since the punch dies  156  have a slightly greater diameter than the wire of the staple  163 , the portions of the staple  163  extending through the set of documents  162  are reliably cut loose and propelled. 
     To accurately position the punch dies  156  relative to the staple to be cut, on the side of the documents  162  where the punch dies  156  are located in the initial position, a template  186  with a recess  187  is pressed against the set  162 . The staple then falls into the recess  187 , so that the position of the staple  163  with respect to the punch dies  156  is defined. The end faces of the punch dies  156  are provided with a profile ensuring that the out-off portions of the staple are held in front of those end faces during the press-away operation. That profile may be designed, for instance, as a concave surface. 
     The residual portion of the staple  163  on the side of the template  186  can be removed in various ways, for instance by a blower or a stiff brush. 
     FIGS. 11 and 12 show an apparatus according to an embodiment of the invention which is presently preferred most as to its general construction. This apparatus comprises a sensor  235  for detecting the position of a staple to be removed, and transport means for displacing a set of documents and the perforator  205  relative to each other, such that the perforator  205  is aligned with the detected position of the staple in the set of documents for providing the perforation in the area of the priorly detected position of the staple. 
     The transport means formed by a transport path  236 , along which are arranged driven and mutually coupled rollers  260  and carriages  241 ,  242  which are mobile along rails  243 ,  244 , transversely to the transport path  236 . 
     Prior to the removal of a staple, the set of documents is scanned for detecting the position of the staple to be removed. Then the documents are displaced along transport path  236  and the perforator  205  is displaced transversely to the transport path until they are displaced relative to each other, such that the perforator is disposed opposite the staple to be removed. The documents can now be reliably perforated in the area of the staple for removing the staple. 
     The drive unit  245  for driving the transport rollers  237 ,  238 ,  239 ,  240  is connected to a control unit  247  via a line  246 . Further, the sensor  235  is connected to the control unit  247  via a line  248 . 
     The position of the staple is determined on the basis of the displacement of the documents along the transport path  236  prior to the detection of the staple and on the basis of the position in the direction transverse to the transport path, where the staple is detected. Then the document is displaced over a fixed distance along the transport path  236  and the carriages  241 ,  242  are displaced along the rails  243 ,  244  into a position corresponding to the position of the staple in transverse direction relative to the transport path  236 . 
     The upper carriage  241  is coupled to a toothed belt  249  which passes over gears in end parts  250  on opposite sides of the rail  243 . The lower carriage  242  is clamped with some friction in the rail  244 . For displacing the carriages  241 ,  242  equally, first the punch  206  of the perforator  205  is set in a position in which it projects into the opening  216  in the die plate  207 . To that end, the entire rail  249 , including the end parts  250 , is moved down relative to the frame  251  of the apparatus. The drive for this can be designed in a manner known per se, for instance with electromagnets which may or may not be enhanced by levers or the like, and is therefore not further described. With the punch  206  in this position, the carriage  241  is displaced and the carriage  242  is carried along. 
     For operating the perforator  205 , the control unit  247  is coupled via a line  252  to the drive (not shown) of the perforator, which drive is mounted on the frame  251 . To control the position of the carriages  241 ,  242  in transverse direction, the control unit  247  is coupled via a line  253  to the drive (not shown) of the toothed belt  249 . 
     To avoid friction during the displacement of the carriage  242 , it may optionally be provided with friction members engaging the rail  244 , which can be set out of operation. 
     It is possible that the position of the staple is such that the set of documents is already disposed between the punch  206  and the die plate  207  before the staple has reached the sensor  235  and the perforator  205  can be set in the proper position in transverse direction. For such situations, it may be provided that the documents are first transported back automatically to clear the area of the perforator  205  and then, after the perforator  205  is set in the desired position in transverse direction, to transport the documents along the transport path  236 , such that the staple is brought opposite the perforator  205 . Renewed detection of the staple as it passes the sensor  235  again may then be utilized for the accurate control of the transport of the documents. If the documents are introduced with the staple in a leading portion, return transport of the documents will generally not be necessary. 
     The perforator  205  is additionally suspended for pivotal motion about an axis  254  in the cutting direction  224 . During the scanning of the set of documents, further the orientation of the staple to be removed is detected and subsequently the perforator  205  is moved relative to the set of documents into an orientation corresponding to the orientation of the staple. To that end, the punch  206  and the die plate  207  are suspended for pivotal motion about said axis  254 , and the punch is mounted in a rotatably suspended carrier  227  which is coupled by a toothed belt  255  to a gear on an output shaft of a stepping motor  256 . The stepping motor is connected to the control unit  247  via a line  257 . 
     The sensor  235  for detecting the position of the staple is designed as a conductivity sensor. By scanning at which points a set of documents transmits a voltage, it can be determined in a simple manner where the typically metal staple is located. 
     The depicted sensor  235  comprises a number of detectors  258  in the form of scanning wheels, distributed in a direction transverse to the direction of transport of the documents. The scanning wheels  258  are represented schematically in FIG. 11, and for clarity only two of them are designated by reference numerals. The voltage is applied to the upper scanning wheels  256 . Failure of the voltage on lower scanning wheels marks the arrival of a leading edge of a set of documents at the location of the sensor  235 . Thereupon, voltage on one or a few of the lower wheels  258  indicates that a staple is located between those wheels. By monitoring which of the lower wheels  258  are subject to a voltage, and registering the position of the documents in the direction of the transport path, the position and the orientation of the staple or staples can be accurately determined. 
     Then, as regards the position of the staple in the direction of transport, it is sufficient to transport the documents over a fixed distance to the perforator  205  to bring the staple exactly to the location of the perforator  205 . 
     Within the framework of the proposed concept, naturally many variations are conceivable. Thus, the perforator may, for instance, be mounted in a fixed position with respect to a conveyor, while the documents are displaceable over the conveyor in the x- and y-directions. Such conveyors are described in U.S. Pat. Nos. 5,222,585 and 5,415,266. 
     For determining the position of the staple, too, various alternative sensors are possible, based on principles for metal detection, known per se, such as a combination of a magnetizer for magnetizing the staple and a sensor sensitive to magnetism, or a combination of an antenna for generating an electromagnetic field and facilities for detecting energy locally absorbed from the field generated. Also various mechanical sensors can be used, such as a ridge for engagement of a staple butting against that ridge, or a thickness sensor. Further, the detection can be carried out in an optical manner, as by the detection of a dispersion characteristic of a metal staple and/or reflection of light of one or more wavelengths, while the light source may be a laser unit producing a line-shaped or planar light beam which is moved along the documents. Such scanners are known per se. Another example of a suitable sensor for determining the position of the staple is a pressure-sensitive film which is pressed against the set of documents by a flat support. Such a film is commercially offered by, for instance, Tekscan, South Boston, Mass., United States.