Patent Publication Number: US-7222402-B1

Title: Box spring stapler apparatus

Description:
This application is a continuation of U.S. application Ser. No. 11/143,403, filed Jun. 2, 2005, which is a continuation of U.S. application Ser. No. 10/306,231, filed Nov. 27, 2002, now U.S. Pat. No. 6,935,546, which claims the benefit of U.S. Provisional Application Ser. No. 60/334,196, filed Nov. 29, 2001, both of which are expressly incorporated by reference herein. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a fastener apparatus for securing a module to a frame. More particularly the present invention relates to a fastener apparatus such as, for example, a stapler apparatus for assembly of a box spring or the like, automatically. 
     Conventional foundations or box springs which are used to support mattresses include a wood frame which supports a plurality of spring modules located at spaced apart positions on the wood frame. Some of these modules are coupled to a wire grid which forms the top surface of the box spring. Other spring modules are formed from a heavy gauge continuous wire which is bent to form vertically extending spring elements. Therefore, the term “module” as used herein is intended to cover any type of conventional support module configured to be coupled to a frame, such as a spring module used in box spring construction. 
     Bottom ends of the spring modules are typically stapled directly to the wood frame of the box spring. During conventional assembly of the box spring, a worker must manually staple each of the plurality of modules to the wood frame using an industrial stapler. Therefore, the manufacturing process is limited to the capability of the individual hired to staple the box spring to the modules. 
     U.S. Pat. No. 5,904,789, which is expressly incorporated by reference herein, discloses an apparatus designed to automate the module fastening process. The apparatus of the &#39;789 patent invention includes a vision guided fastening apparatus which automatically locates the modules on the frame and then guides a fastener tool, such as a stapler, into proper position to secure the modules to the frame automatically. The &#39;789 patent apparatus is designed to accommodate different size box springs, such as twin, full, queen, and king sizes. In addition, the apparatus is programmable to secure any type of module to the wood frame. 
     As discussed below, the present invention provides a fastener apparatus which does not require the vision guidance system of the &#39;789 patent. The apparatus of the present invention includes a mechanical guide coupled to the stapler or other fastening tool. The mechanical guide guides the fastening tool into proper alignment with a target during the fastening process. 
     In an illustrated embodiment of the present invention, an apparatus is provided for securing a plurality of modules to a frame. The apparatus comprises a base for supporting a frame and a plurality of modules, a support, and a drive mechanism coupled to at least one of the support and the base. The drive mechanism is configured to provide relative movement between the support and the base. A tool is coupled to the support. The tool is configured to secure each module to the frame. The apparatus also includes a mechanical guide coupled to the tool. The mechanical guide is configured to engage the module to guide the tool to a target fastening location on the module. 
     The illustrated drive mechanism includes a controller configured to guide movement of the support relative to the base and the frame and modules located on the base, thereby moving the tool to secure each of the modules to the frame. The controller includes a memory for storing a plurality of standard positions for each of the modules on the frame and means for guiding the tool to the plurality of stored standard positions. 
     The illustrated mechanical guide includes a support coupled to the tool and first and second guide wings pivotably coupled to the support. The guide wings are each configured to engage the module as the tool moves toward the module to guide the tool to the target fastening location. In the illustrated embodiment, each of the guide wings includes first and second ramp surfaces configured to engage the module. 
     Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the presently perceived best mode of carrying out the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description particularly refers to the accompanying figures in which: 
         FIG. 1  is a block diagram illustrating components of a module fastening apparatus of the present invention; 
         FIG. 2  is a perspective view illustrating one embodiment of a box spring including a wood frame and, a plurality of spring modules located on the wood frame, and illustrating a stapler having a mechanical guide of the present invention movable to fasten the modules to the wood frame; 
         FIG. 3  is an end elevational view illustrating the stapler and mechanical guide advancing downward/toward a target on a portion of a module to secure a portion of the module to the frame; 
         FIG. 4  is a sectional view taken through the stapler of  FIG. 3  illustrating the mechanical guide in detail; 
         FIG. 5  is an end elevational view similar to  FIG. 3  showing further movement of the stapler as the mechanical guide approaches opposite side portions of the module; 
         FIG. 6  is an end elevational view similar to  FIGS. 3 and 5  illustrating engagement of the mechanical guide with opposite side portions of the module; and 
         FIG. 7  is an end elevational view illustrating pivotable movement of portions of the mechanical guide relative to the stapler to guide the stapler into proper position to secure the module to the frame at the target. 
     
    
    
     DETAILED DESCRIPTION OF DRAWINGS 
     Referring now to the drawings, the present invention is related to fastener apparatus for securing modules to a frame. The illustrated embodiment is a box spring stapler apparatus. A related apparatus is disclosed in U.S. Pat. No. 5,904,789 which is expressly incorporated herein by reference. The &#39;789 patent discloses an apparatus and method using a vision guidance system for finding targets during the formation of box spring foundation units or other structures in which modules are coupled to frames. The prior system is very flexible and universal and provides vision targeting usable to form all types of box spring foundation units or other structures in which modules are fastened to frames. 
     Some box spring foundation units use a three dimensional wire weldment as the spring system for the box spring. One such unit is the Semi-Flex® box spring assembly illustrated in  FIG. 2 . A spring unit  10  includes a continuous wire having a top portion  12  and a plurality of troughs or spring modules  14 . Each spring module  14  has first and second vertically extending side portions  16  and  18  and a horizontal bottom portion  20  located between the first and second vertically extending side portions  16  and  18 . Bottom portion  20  abuts a section  22  of a wood frame  21 . Several of the wires extend across the width of the box spring at spaced apart locations as shown in  FIG. 2 . Spring modules  14  are aligned with each of the wood frame sections  22  of the bottom frame  21  of the box spring. 
     As illustrated in  FIG. 1 , the present invention provides a base  24  for supporting frame  21  and plurality of spring units  10 . A support  26  is located above the base  24 . Support  26  holds a fastening tool  30  for securing the modules  14  to the frame sections  22 . A mechanical guide  32  is coupled to the tool  30  in order to mechanically position the tool  30  in a proper fastening position relative to each module  14 . A drive mechanism  28  is coupled to one of the base  24  and support  26  to provide relative movement between the base  24  and the support  26 . If needed, a bottom gantry (not shown) having an alignment tool  25  is provided below the base  24  to position the spring units  10  relative to the frame sections  22  as shown in the &#39;789 patent. In one illustrated embodiment, cable drive mechanisms are used to move the support relative to the base. See, for example, the cable drive mechanism illustrated in the &#39;789 patent. In other words, either the mechanical guide  32  or the alignment tool  25  may perform the step of moving the module  14  and/or the tool  30  to compensate for misalignment of the module  14  relative to at least one of the frame section  22  and/or the fastening tool  30  before the module  14  is secured to the frame section  22  as discussed below in more detail. 
     The spring unit  10  is constructed such that a stapler head  30  can approach the target at the bottom portion  20  of modules  14  in a direction perpendicular to the base  24  supporting the frame  21 . Spring unit  10  has three features which simplify the stapling task. First, the dimensional tolerances of the target are very good. Second, the target can be approached perpendicular to the base  24 . Third, a large access area is available. 
     As discussed above, the present invention provides a mechanical guide  32  coupled to the tool or stapler head  30 . Mechanical guide  32  is used to steer the stapler head  30  to a target on bottom portion  20  of module  14  without the use of the vision guidance system of the &#39;789 patent. The mechanical guide  32  therefore provides a lower cost guidance system. In addition, since the vision guidance system targets acquisition time is eliminated, the hit speed of the stapler  30  is increased. It is understood that the mechanical guide  32  may also be used with a vision guidance system. In this embodiment, the vision guidance is less exact in guiding the stapler  30  directly to the target as in the &#39;789 patent, but could provide vision guidance to an initial position adjacent each module. 
       FIG. 3  illustrates position of stapler head  30  and mechanical guide  32  when the stapler head  30  moved into position between first and second vertically extending side portions  16  and  18  of spring module  14 . As best shown in  FIG. 4 , mechanical guide  32  illustratively includes a support  34  attached to a nose  36  of stapler head  30 . The guide  32  also includes first and second guide wings  38  and  40  which are pivotably coupled to support  34  about a pivot axis  42  by pivot connectors  44  and  46 . Each of the guide wings  38  and  40  illustratively includes a V-shaped notched portion  37  and  41 , respectively. Notched portion  37  of guide wing  38  is defined by ramp surfaces  50  and  52 . Notched portion  41  of guide wing  40  is defined by ramp surfaces  51  and  53 . In the illustrated embodiment, a wheel or roller bearing  54  is rotatably coupled to each guide wing  38  and  40  about pivot axes  56  and  58 , respectively. It is understood that the wheels  54  may be omitted or replaced by low friction skids or other similar structure. 
     As stapler head  30  is moved downwardly in the direction of arrow  60  in  FIG. 3 , the stapler head  30  and guide  32  move to the position shown in  FIG. 5 . In  FIG. 5 , the wings  38  and  40  begin to approach vertically extending side portions  16  and  18 , respectively. Ramp surfaces  50  and  52  of guide wing  38  and ramp surfaces  51  and  53  of guide wing  40  are configured to engage the wire and guide the stapler head  30  to a center position to align stapler head  30  with the target on bottom portion  20  as the stapler head  30  is moved downwardly. Depending upon the initial alignment of stapler head  30 , various portions of ramp surfaces  50  and  52  or  51  and  53  engage the side portions  16  and  18 , respectively. Because stapler head  30  is pivotably mounted to a support assembly as disclosed in the &#39;789 patent, stapler head  30  can move as the wings  38  and  40  engage the downwardly extending portions  16  and  18 . 
       FIG. 6  illustrates the position of the stapler head  30  and the mechanical guide  32  when stapler head  30  is moved further in the direction of arrow  60  so that the rollers  54  engage the first and second side portions  16  and  18 . When in the position of  FIG. 6 , the stapler head  30  is aligned with the target  20  since the stapler head  30  is centered between the side portions  16 ,  18 . Rollers  54  reduce contact friction between the mechanical guide  32  and the wire forming side portions  16  and  18  to facilitate targeting. 
     As shown in  FIG. 7 , guide wings  38  and  40  pivot upwardly in the direction of arrows  70  and  72 , respectively, as the stapler head  30  continues downward movement in the direction of arrow  60  and engages the target on bottom section  20 . Left and right guide wings  38  and  40  are illustratively spring loaded by springs  41  located on opposite sides of support  34  so that the normal positioning of the guide  32  is the generally horizontal position shown in  FIGS. 3 ,  5 , and  6 . Each spring  41  includes a first arm portion  43 , a second arm portion  45 , and a central coil portion  47 . Central coil portion  47  extends along pivot axis  42 . First arm  43  applies a downwardly directed force to guide wing  38 . Second arm  45  applies a downwardly directed force to guide wing  40 . Therefore, guide wings  38  and  40  are biased downwardly against stops  39  located on opposite sides of the support  34 . 
     If one roller  54  contacts the wire element before the opposite side roller  54 , the stapler head  30  is moved in an opposite direction from the contacted side. This movement continues until the roller  54  on the opposite side wing intersects the opposite side portion of the wire element. The spring forces applied by springs  41  to the guide wings  38  and  40  are great enough so that the guide wings  38  and  40  do not pivot upwardly until both guide wings  38  and  40  have engaged the side portions  16  and  18 . Once both rollers  54  have contacted both side portions  16  and  18 , the wings  38  and  40  begin to pivot upwardly about pivot axis  42 . This provides forces needed to move the stapler head  30  to a point midway between the first and second portions  16  and  18 , thereby targeting the stapler head  30  in a center of the bottom portion  20  of the wire element located on wood frame  22 . This insures proper positioning of staples  80  shown in  FIG. 2 , or proper positioning of other suitable fasteners such as nails, glue, or the like. 
     In the illustrated embodiment of the present invention, a controller is a Cartesian robot structure made up of a work table having an X-axis and a Y-axis, an industry standard stapler (or other fastener), a stapler Z-axis drive system, a drive mechanism and a driver/controller system for each axis of motion. The stapler does not require the T-axis and U-axis drive motors disclosed in &#39;789 patent. In addition, a stapler rotation motor is not required. Illustratively, the stapler is fixed in one rotary position relative to the target bottom portion  20  of the wire elements where the staples  80  are installed. The support  26  is illustratively held in a vertical position by four springs, one on each side of an upper portion of a mounting system. The springs allow movement of the support  26  as the guide  32  engages the vertically extending side portions  16  and  18  of the wire module  14 . Therefore, as discussed above, the system of the present invention does not require vision guidance system to align the tool  30  with the target. 
     In operation, the standard position of each of the spring modules  14  relative to the frame  21  is programmed into the control system. The driver/controller moves the stapler head  30  to the pre-programmed standard positions and then moves the stapler head  30  downwardly to insert a stapler  80  or other fastener at the target locations to secure the bottom portions  20  to frame sections  22 . As discussed above, vision guidance (generally shown as sensor  31  in  FIG. 1 ) may be used to determine that the modules are in the standard positions and make sure that the tool  30  is initially aligned with the module  14 . In another embodiment, magnetic sensors are used to locate the upper portion of the wire. The magnetic sensors are located adjacent the guide  32  and provide active feedback to the controller to move the stapler head  30  and guide  32  to the standard position over a module  14 . However, the mechanical guide  32  provides final alignment of the stapler head  30  with the target bottom portion  20  during the stapling process as discussed above. 
     Although the present invention has been described in detail with respect to a box spring stapler apparatus, it is understood that other types of modules may be fastened in accordance with the present invention. In addition, various fastening tools may be used with the mechanical guide of the present invention other than the disclosed stapler. These tools include, for example, a nailer, a glue dispenser, or other fastening device. 
     It is understood that the mechanical guide  32  may also have a different structure to accomplish the alignment of the tool  30  with the fastening target. For example, in another embodiment, guide  32  is made from a flexible material that bends as it contacts the side portions  16  and  18  of the module  14 . This flexible guide has the same shape as shown in  FIG. 4 , and is made from a flat piece of flexible material mounted to support  34 . The material is illustratively a plastic material having good wear capability and flexibility. The material may also be metal with anti-friction pads located where the rollers  54  are located in  FIG. 4 . Rollers  54  are optional, but may be used if desired. This embodiment eliminates the hinged guide wings and related pivots and springs. The guide  32  is an integral one-piece guide made of flat, springy material with the same “V” shape on the ends. 
     Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of the present invention as described and defined in the following claims.