Patent Publication Number: US-6991146-B2

Title: Stapler having detached base

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Patent Application No. 60/367,101, filed Mar. 25, 2002, the disclosure of which is hereby incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention relates generally to staplers for attaching a plurality of sheets of paper, or the like, to each other or to a surface, and particularly to a hand-operated stapler having a detached base. 
   BACKGROUND OF THE INVENTION 
   Staplers using wire staples for attaching sheets of paper and other similar materials together are common in corporate, institutional, and educational environments. Manually operated and electrically powered staplers are well known and in widespread use. Exemplary manual staplers are shown in U.S. Pat. Nos. 2,973,519 to Jopp, 4,491,261 to Mitsuhashi, 4,496,091 to Yasuda, 4,506,819 to Rand and 4,927,067 to Leszczak, the disclosures of which are hereby incorporated herein by reference. These staplers are typical of those well known in the art in that they have an anvil-supporting base and a staple-driving stapling assembly mechanically coupled to the base by a fixed hinge. The stapling assembly is typical of those well known in the art in that they include a magazine pivotally mounted to the base for holding a bar of U-shaped staples interconnected in a readily separable manner, and an upper body including a staple ejector for driving successive staples out of the magazine, through sheets of paper, etc. and against the anvil on the base to crimp the legs of the staple and fasten the sheets. 
   These and other conventional staplers having a mechanically coupled base and stapling assembly share a disadvantage in that they define a throat between the base and stapling assembly that has a fixed depth. The throat depth limits the distance from the edge of a sheet at which at staple may be placed. In other words, because of the fixed hinge attaching the base and stapling assembly, the anvil and staple ejector can reach inwardly only a limited distance from an edge of a sheet, i.e. to the point at which the edge of the sheet reaches an inner portion of the throat near the fixed hinge. 
   This limitation is undesirable in some stapling situations, e.g. where there is a desire to perform “saddle stitching” staples in the center of the width of an 11 inch high by 17 inch wide sheet of paper to permit a fold producing a booklet measuring approximately 8-½ inches wide by 11 inches high. Similarly, such conventional staplers are inadequate on large-scale projects, e.g. on posterboard or other relatively large scale projects such as student&#39;s art displays, on bulletin boards, on corporate or promotional displays, etc., where large-sized sheets are used. The use of large-sized sheets prohibits stapling at certain locations interior to the edges of the sheets using conventional staplers, and limits stapling to portions of the sheets near the edges. 
   What is needed is a stapler capable of stapling sheets at any desired location, including interior locations of relatively large-scale sheets. 
   SUMMARY OF THE INVENTION 
   The present invention provides a stapler having a staple-driving stapling assembly and a detached anvil-supporting base that are magnetically couplable. The magnetic coupling feature eliminates throat depth limitations caused by the fixed hinge of mechanically coupled staplers of the prior art, and allows for staple placement at any desired location on any size of sheet. Additionally, the stapling assembly may be used apart from the anvil-supporting base to drive staples into a bulletin board, etc. when crimping of the staples is not required. 
   In accordance with the present invention, a stapler with a detached base includes a base supporting an anvil and a first magnetic element, and a stapling assembly for ejecting staples from a magazine port. The stapling assembly supports a second magnetic element positioned for magnetic coupling to the base to align the anvil with the magazine port. 
   Optionally, the base and/or the stapling assembly includes an alignment guide visually indicating an approximate location where a staple will be placed if driven by the stapling assembly. 
   In certain embodiments, the base and the stapling assembly are provided with friction pads positioned to cooperatively limit movement of any sheets therebetween while driving a staple from the stapling assembly and against the anvil of the base. 
   In a particular alternative embodiment, the base is provided with an annular magnet, the anvil being positioned interior to the annular magnet, and the anvil defining a plurality of radially extending crimping surfaces such that the base and stapling assembly may be magnetically coupled and operated to clinch staples in various relative rotational positions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a stapler in accordance with an exemplary embodiment of the present invention, showing the stapling assembly magnetically coupled to the base; 
       FIG. 2  is a bottom view of the stapler of  FIG. 1 ; 
       FIG. 3  is sectional view of the stapler of  FIG. 1 , taken along line  3 — 3  of  FIG. 2 ; 
       FIG. 4  is a sectional view of the stapler of  FIG. 1 , taken along line  4 — 4  of  FIG. 3 ; 
       FIG. 5  is a plan view of the stapling assembly of  FIG. 1 , showing the stapling assembly in an open position; 
       FIG. 6  is a bottom view of the stapling assembly of  FIG. 1 ; 
       FIG. 7  is a top view of the base of  FIG. 1 ; 
       FIG. 8  is a perspective view of an exemplary base in accordance with an alternative embodiment of the present invention; 
       FIG. 9  is a perspective view of an exemplary base in accordance with another alternative embodiment of the present invention; 
       FIG. 10  is a perspective view of an exemplary base in accordance with yet another alternative embodiment of the present invention; and 
       FIG. 11  is a perspective view of an exemplary base in accordance with still another alternative embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
     FIGS. 1–7  show a stapler with detached base in accordance with the present invention. As shown in  FIGS. 1 and 3 , the stapler  10  includes a base  12  and a stapling assembly  50 . 
   As best shown in  FIG. 7 , the base  12  supports an anvil  14  defining crimping surfaces  14   a ,  14   b  for crimping staples driven by the stapling assembly  50 , as is well known in the art. In accordance with the present invention, the base  12  also supports a first magnetic element. As used herein, the term “magnetic element” includes a member capable of attracting another body by magnetism, as well as a member capable of being attracted to another body by magnetism. For example, a magnetic element may include a natural lodestone or a mass of iron, steel, or alloy that has been artificially magnetized, such as a neodymium magnet. Additionally, a magnetic element may include a mass of iron that is attractable by magnetism. 
   In the embodiment shown in  FIGS. 1–7 , the first magnetic element  16  includes first and second permanent magnets  16   a ,  16   b , such as neodymium magnets, supported on the base  12  in a spaced relationship, as best shown in  FIGS. 4 and 7 . The use of multiple discrete magnets spaced from one another assists in ensuring proper alignment with the stapling assembly, as discussed in greater detail below. As shown in  FIGS. 6 and 7 , the magnets  16   a ,  16   b  are positioned on the base  12  along a line extending transversely to a longitudinal axis of a magazine  52  of the stapling assembly  50  when the stapling assembly  50  is coupled to the base  12 , as will be discussed further below. Alternatively (not shown), the magnets  16   a ,  16   b  are positioned on the base along a line extending substantially parallel to the longitudinal axis of the magazine. 
   In a preferred embodiment, the magnets  16   a ,  16  are positioned so that each exposes an opposite magnetic pole for coupling to the stapling assembly. For example, as shown in  FIG. 7 , magnet  16   a  is positioned on the base to expose its north pole while magnet  16   b  is positioned on the base  12  to expose its south pole. In this manner, coupling of the base and the stapling assembly in a predetermined relationship is ensured, as discussed in greater detail below. 
   The stapling assembly  50  is configured for ejecting staples from a magazine port, as is well known in the art. Accordingly, the stapling assembly  50  may be of a type generally known in the art. For example, as shown in  FIGS. 3–6 , the stapling assembly  50  includes a magazine  52  for receiving a bar of staples  54  interconnected in a readily separable manner, and a selectively actuatable ejector  56  for driving successive staples out of the magazine  52  through a magazine port  58 . In addition, the stapling assembly  50  may include a handle  60  pivotally mounted to the magazine  52  by pins  62 , such that pivotal motion of the handle  60  relative to the magazine  52  actuates the ejector  56  to eject a staple, at which point the handle, magazine and ejector are spring biased to return to their original position. The handle  60  may include a lower handle body  60   a  supporting the magazine  52  and an upper handle body  60   b  pivotally connected to the lower handle body  60   a . The upper handle body  60   b  supports the ejector  56 . This and other suitable arrangements are well known in the art and any suitable arrangement may be used that provides the above-described functionality. Accordingly, the stapling assembly  50  of the present invention functions to receive, store and drive staples like a conventional stapling assembly. 
   However, in accordance with the present invention, the stapling assembly  50  includes a magnetic element magnetically couplable with the magnetic element  16  on the base  12 , as best shown in  FIGS. 4 and 6 . For example, the magnetic element  64  on the stapling assembly  50  may comprise a magnet, or a member capable of being attracted to a magnet by magnetism. In embodiments in which magnets are disposed on both the stapling assembly  50  and the base  12 , each magnet on the stapling assembly  50  is arranged to expose an opposite pole of a corresponding magnet on the base  12 . The magnetic element on the stapling assembly  50  is positioned on the stapling assembly  50  for magnetically coupling the base  12  to the stapling assembly  50  to align the anvil  14  with the magazine port  58 . 
   In the embodiment shown in  FIGS. 1–7 , the magnetic element  64  of the stapling assembly  50  includes third and fourth permanent magnets  64   a ,  64   b , such as neodymium magnets, supported on the stapling assembly  50  in a spaced relationship corresponding to the spaced relationship of the first and second magnets  16   a ,  16   b  on the base  12 . As shown in  FIG. 6 , the magnets  16   a ,  16   b  and  64   a ,  64   b  are positioned along a line extending transversely to a longitudinal axis of the magazine  52 . 
   In a preferred embodiment, as best shown in  FIG. 4 , the base  12  further includes spring members  22   a ,  22   b  biasing the first magnets  16   a ,  16   b , respectively, from a first position in which a contact surface  18  of the first magnets  16   a ,  16   b  is substantially aligned with a plane  20  of the anvil  14  (not shown), to a second position in which the contact surface  18  is spaced from the plane, as shown in  FIG. 4 . The spring members  22   a ,  22   b  comprise, for example, a pair a coil springs as shown. However, it is understood that any biasing means that will urge the magnets  16   a ,  16   b  upward, e.g. a “living spring,” leaf spring, resilient material, etc. may be used as spring members  22   a ,  22   b . In this manner, the magnets  16   a ,  16   b  are resiliently displaceable from the plane  20  of the anvil  14 , to provide clearance for a crimped staple ejected from the stapling assembly  50 , as discussed in detail below. 
   Preferably, as best shown in  FIGS. 3 ,  4 ,  6  and  7 , the base  12  includes a first friction pad  28  and the stapling assembly  50  includes a second friction pad  66 . The pads are constructed of a material having a relatively high coefficient of friction, such as rubber or Krayton. The first and second friction pads  28 ,  66  are positioned to cooperatively hold sheets positioned therebetween to limit movement of the sheets relative to the base  12  and/or stapling assembly  50  while driving a staple from the stapling assembly  50  and against the anvil  14  of the base  12 . Each friction pad may include one or more discrete pads. 
   In accordance with the present invention, the base may have various alternative configurations, as discussed below with reference to  FIGS. 8–11 . In the alternative embodiments shown in  FIGS. 8 and 9 , the base  12  is configured with a cantilevered beam for supporting the magnetic element in a similar resiliently displaceable manner. This eliminates the need for spring members  22   a ,  22   b  of  FIGS. 1–7 . For example,  FIG. 8  shows cantilevered beam(s)  24   a ,  24   b , each of which is integrally formed with the base  12 , e.g. by an injection molding or machining process, for supporting magnets  16   a ,  16   b . The cantilevered beams  24   a ,  24   b  are separated from a portion of the base  12  by slits  25  to allow the cantilevered beams  24   a ,  24   b  to flex relative to the base  12 . 
   In the embodiment shown in  FIG. 8 , the contact surface  18  of the magnets  16   a ,  16   b  are resiliently displaceable to a position in which the magnets&#39; contact surface  18  is substantially aligned with the plane  20  of the anvil  14 , similarly to the embodiment discussed above with reference to  FIGS. 1–7 . This is particularly advantageous when the magnetic element is positioned relatively close to the anvil, as shown in  FIGS. 1 and 8 . Accordingly, positive abutting contact between the magnetic elements on the base and the stapling assembly can be maintained throughout the stapling process, while the cantilevered beam resiliently deflects in a pivoting motion. 
   In the alternative embodiment shown in  FIG. 9 , the cantilevered beam  24  is provided in the form of a mesa  26  separated from a portion of the base  12  by slits  25 . The mesa  26  supports the contact surface  18  of the magnets  16   a ,  16   b  in a position spaced above the plane  20  of the anvil  14 . Such a cantilevered beam  24  is particularly advantageous when the magnetic element is positioned relatively far from the anvil, as shown in  FIG. 9 . Accordingly, positive abutting contact between the magnetic elements on the base and the stapling assembly can be maintained throughout the stapling process, while the cantilevered beam  24 , which is integral with the base, resiliently deflects in a pivoting motion to allow the stapling assembly&#39;s magazine  52  to move toward the anvil  14 . 
   In the alternative embodiment shown in  FIG. 10 , the base  12  defines a fixed mesa  26 . The mesa  26  supports the contact surface  18  of the magnets  16   a ,  16   b  in a position spaced above the plane  20  of the anvil  14 . There is no cantilevered beam supporting the magnets  16   a ,  16   b  on the base  12 . In this embodiment, in which the magnetic element is positioned relatively far from the anvil, positive contact between the magnetic elements on the base and the stapling assembly is not maintained throughout the stapling process. Rather, the magnetic elements allow a small separation during stapling to allow the magazine  52  to pivot at the mesa  26  toward the anvil  14 . 
   In another alternative embodiment shown in  FIG. 11 , the magnetic element  16  mounted on the base  12  (or the stapling assembly  50 ) comprises an annular magnet, and the anvil  14  is positioned interior to the annular magnet  16  on the base  12 . The anvil  14  is configured to define a plurality of radially extending crimping surfaces  14   a ,  14   b ,  14   c ,  14   d ,  14   e ,  14   f , etc. In this manner, the base  12  and stapling assembly  50  may be magnetically coupled at various relative rotational positions and yet a staple driven from the stapling assembly  50  can be crimped by corresponding crimping surfaces of the anvil  14 . 
   In certain embodiments, the stapler includes an alignment guide visually indicating a location where a staple will be placed if driven by the stapling assembly  50 . The alignment guide may have any suitable form. Longitudinal and lateral alignment guides may be provided. For example, a stripe  30  may be painted on or molded into the base  12  or stapling assembly  50 , as shown in  FIGS. 8 and 10 . The stripe may be aligned with the crimping surfaces  14   a ,  14   b  of the anvil  14 . Alternatively, the alignment guide may include ears, tabs, etc.  32 , as shown in  FIG. 9 . In another embodiment, at least a portion of the base and/or stapling assembly is constructed of a transparent material to see the anvil, magazine, or alignment guides (not shown). Preferably, the alignment guide is plainly visible when looking downward on the top of the stapling assembly  50 . 
   A stapler  10  according to the present invention may be prepared for use by positioning sheets to be stapled, of any size, over the base  12 . The stapling assembly  50 , having a bar of staples loaded in its magazine, may then be positioned over the sheets in the approximate location of the base. The magnetic elements of the base  12  and stapling assembly  50  will then cause the base and stapling assembly to magnetically couple with the anvil  14  of the base  12  in alignment with the magazine port  58  of the stapling assembly  50 . If desired, the stapler  10  may be repositioned relative to the sheets by sliding the stapling assembly relative to the sheets. The base  12  moves correspondingly to preserve the proper alignment due to the magnetic coupling of the base and stapling assembly. When the stapler  10  is positioned in the desired location, the ejector  56  of the stapling assembly  50  is actuated, e.g. by forcibly urging an upper handle member of the stapling assembly toward the base  12 . This causes the ejector to drive a staple from the bar of staples in the magazine  52 . The staple exits through the magazine port  58  and passes through the sheets and into the anvil, at which time the legs of the staple are crimped by the crimping surfaces of the anvil to fasten the sheets. During this stapling process, the friction pads, if any, are urged toward the sheets and toward one another to grip and hold the sheets during the stapling process. Additionally, the magnetic elements on the base and/or stapling assembly, if applicable, are resiliently deflected. However, as the stapling assembly  50  returns to a rest position, e.g. by spring biasing as known in the art, the cantilevered beams, and/or spring elements return to their rest positions, causing the sheets to at least partially disengage from the friction pads and to separate the base and anvil and the stapling assembly to provide clearance for the crimped staple fastening the sheets and facilitate movement or removal of the stapler  10  relative to the sheets without tearing the sheets. 
   Having thus described particular embodiments of the invention, various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications and improvements as are made obvious by this disclosure are intended to be part of this description though not expressly stated herein, and are intended to be within the spirit and scope of the invention. Accordingly, the foregoing description is by way of example only, and not limiting. The invention is limited only as defined in the following claims and equivalents thereto.