Patent Publication Number: US-9895739-B2

Title: Apparatus for making border wire

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 13/851,331 filed Mar. 27, 2013 which claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/617,275 filed Mar. 29, 2012 entitled “Method of Making Border Wire and Apparatus For Practicing Method”. Each application is fully incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to bedding products and the method and apparatus for making a rectangular border wire or frame used in a bedding or seating product. 
     BACKGROUND 
     In the bedding industry, bedding foundations and spring cores used for mattresses have at least one border wire. The border wire may assume a rectangular shape, including a square. 
     The border wires of spring cores used for mattresses and sometimes furniture, including seating products, are usually made from wire having a circular cross-section. However, applicant&#39;s U.S. patent application Ser. No. 12/821,754, published on Dec. 29, 2011 as Publication No. 2011/0314613, and fully incorporated by reference herein, discloses a spring core having a border wire having a rectangular cross-section. 
     In addition, a bedding foundation or box spring may have a rectangular border wire having a circular cross-section. However, applicant&#39;s U.S. Pat. Nos. 8,327,475 and 8,332,974, each being fully incorporated by reference herein, disclose a bedding foundation having a border wire having a rectangular cross-section. 
     Straightening wire having a rectangular cross-section requires a different apparatus than straightening wire having a circular cross-section. The apparatus used to straighten wire having a circular cross-section requires adjustment to the machinery be made manually. The apparatus used to straighten wire having a rectangular cross-section may use servo motors to manipulate the wire electronically. Applicant&#39;s U.S. patent application Ser. No. 13/179,039, fully incorporated by reference herein, discloses an apparatus used to straighten wire having a rectangular cross-section. The use of servo motors enables wire having a rectangular cross-section to be straightened quickly and easily without manual mechanical adjustments. The set-up time is much less with the apparatus disclosed in applicant&#39;s U.S. patent application Ser. No. 13/179,039. 
     Thus, a need exists in the art for an automated method of making a border wire made of wire having a rectangular cross-section. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention, a method of making a border wire for a bedding product comprises providing a source of wire having a circular cross-section, unwinding it from its roll and straightening it. The next step comprises passing the wire having a circular cross-section through a metal forming machine to create a wire having a rectangular cross-section. The next step comprises accumulating the wire having a rectangular cross-section in an accumulator. The wire having a rectangular cross-section is then passed through a three-axis straightener. A predetermined length of wire having a rectangular cross-section is measured. The next step comprises cutting the wire having a rectangular cross-section to a predetermined length to obtain a piece of wire having a rectangular cross-section. The piece of wire having a rectangular cross-section is then bent using four bending assemblies into a rectangular configuration. Opposed ends of the piece of wire having a rectangular cross-section are welded together to create a rectangular border wire. 
     According to another aspect of the invention, an apparatus for making a rectangular border wire having a rectangular cross-section comprises a wire holder adapted to hold a roll of wire having a circular cross-section. The apparatus further comprises a wire payoff and a two-plane straightener downstream of the wire payoff. The apparatus further comprises a metal forming machine downstream of the two-plane straightener which changes the cross-sectional shape of the wire along with an accumulator downstream of the metal forming machine. A three-axis straightener is located downstream of the accumulator, and a feed assembly is provided downstream of the three-axis straightener. A bender section comprising multiple bender assemblies driven by servo motors is located downstream of the cutter; and a welder is located proximate the bender section. The apparatus may further comprise an ejector. 
     The present straightening method allows the wire straightening to be completed quickly and, in most cases, without the use of mechanical tools. The adjustments may be repeatable and more precise than heretofore. Stored data allows for quick changes and repeatable set-ups between wire gauges and heats. Border wires having rectangular cross-sections may be made more quickly than conventional border wires having round cross-sections using the present method and apparatus. The amount of scrap metal is reduced using the present invention. Contact and non-contact detection systems may automatically detect the position and orientation of the wire. These systems may include at least one of the following: laser systems; vision systems; object detection systems using insensitive probes; magnetic field detection systems; ultrasonic field detection systems; and, sonar measuring systems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. In the figures, corresponding or like numbers or characters indicate corresponding or like structures. 
         FIG. 1  is a perspective view of one embodiment of the apparatus of the present invention. 
         FIG. 1A  is a side elevational view of the apparatus of  FIG. 1 , the path of wire travel being partially shown. 
         FIG. 1B  is a side elevational view of a portion of the apparatus of  FIG. 1 , the bending of wire being shown. 
         FIG. 2  is an enlarged perspective view of a portion of the apparatus of  FIG. 1 . 
         FIG. 2A  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 2 . 
         FIG. 2B  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 2 . 
         FIG. 2C  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 2 . 
         FIG. 3  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 2 . 
         FIG. 3A  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 3 . 
         FIG. 3B  is a cross-sectional view of the portion of the apparatus shown in  FIG. 3A . 
         FIG. 3C  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 3 . 
         FIG. 3D  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 3 . 
         FIG. 3E  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 3 . 
         FIG. 4  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 2 . 
         FIG. 5  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 4 . 
         FIG. 5A  is an enlarged perspective view of the portion of the apparatus shown in  FIG. 5 . 
         FIG. 5B  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 5 . 
         FIG. 6  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 3 . 
         FIG. 6A  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 6 . 
         FIG. 6B  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 6 . 
         FIG. 6C  is an enlarged perspective view of a portion of the apparatus shown in  FIG. 6 . 
         FIG. 7  is a rear perspective view of a portion of the apparatus of  FIG. 1 . 
         FIG. 8  shows a flow chart of the operation of the apparatus. 
     
    
    
     DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS 
     Referring to the figures, and particularly to  FIG. 1 , an apparatus for making a border wire having a rectangular cross-section is generally indicated by the numeral  10 . The apparatus  10  comprises a wire payoff  12  for unwinding wire having a round cross-section  13  from a spool  14  of wire (shown in  FIG. 1A ). 
     Downstream of the wire payoff  12  is a two-plane wire straightener  16 . 
     Downstream of the two-plane wire straightener  16  is a metal forming machine  18  which changes the cross-sectional configuration of the wire  13  from a round cross-section to a rectangular cross-section. This type of metal forming machine  18  is known in the industry as a Turks Head. One suitable Turks Head is available from the FENN division of SPX Precision Components based in Newington, Conn. The wire having the rectangular cross-section is denoted by the number  19  in the drawings. 
     A wire accumulator  20  is located at one end of the apparatus  10  downstream of the metal forming machine  18 . The wire accumulator  20  has a plurality of spaced rollers  21  around which the wire having the rectangular cross section  19  passes. 
     A three-axis straightener  22 , such as the one disclosed in U.S. patent application Ser. No. 13/179,039, fully incorporated by reference herein, is located downstream of the wire accumulator  20 . The details of the three-axis straightener  22  are shown in  FIGS. 2A and 2B . 
     A feed assembly  24 , including feed rollers  43  driven by a servo motor  42 , is located downstream of the three-axis straightener  22 . The feed assembly  24 , or feeder, measures a predetermined length of wire which passes therethrough before being cut. The details of the feed assembly  24  are shown in  FIGS. 2A, 2B and 2C . 
     A bender section  26 , comprising four bending assemblies  28   a - 28   d , is located downstream of the feed assembly  24 . Upper bending assemblies  28   a  and  28   b  are located above lower bending assemblies  28   c  and  28   d , respectively. As best shown in  FIG. 7 , each bending assembly  28   a - 28   d  is driven by a servo motor  82 , which may be independently programmed. 
     A welder unit  100  is located between the lower bending assemblies  28   c  and  28   d . The details of the welder unit  100  are shown in  FIGS. 6, 6A, 6B and 6C . 
     Lastly, a catwalk  27  is part of the apparatus and has a ladder  25  at one end to enable a person to walk up to the catwalk  27 . 
     The drawings, and, in particular,  FIGS. 1A and 1B , illustrate the method of making a border wire  30  having a rectangular cross-section. As shown in  FIG. 1A , a spool of wire  14  having a circular cross-section is unwound using the wire payoff  12 . The unwound wire  13  is passed through the two-plane wire straightener  16  and then though the metal forming machine  18 , which changes the cross-sectional configuration of the wire  13  from a round cross-section to a rectangular cross-section. The wire  19  having a rectangular cross-section is then accumulated in wire accumulator  20 . The wire  19  passes around the rollers  21  of the wire accumulator  20 . Wire accumulator  20  allows enough wire to build up or accumulate therein so that during the border feed process, the metal forming machine  18 , or Turks Head, is seldom, if ever, required to stop operating during production. A lower portion of wire accumulator  20  may move vertically during operation to adjust the amount of wire in the wire accumulator  20 . In practice, the wire  19  may pass around the wire accumulator  20  twice to create two loops around the outside of rollers  21 . 
     The wire  19 , having a rectangular cross-section, is then pulled through the three-axis straightener  22  by the feed assembly  24 . The feed assembly  24  measures the desired length of wire  19  and cuts it to length to obtain a piece of wire  36  shown in  FIG. 1B . 
     The piece of wire  36  having a rectangular cross-section is supported by a support  38 , which may be adjusted in length. The piece of wire  36  is then bent from a straight piece into a rectangular configuration by multiple bender assemblies  28   a - 28   d  in the bender section  26 . Upper bending assemblies  28   a  and  28   b  bend the piece of wire  36  into a generally inverted U-shape. Each upper bending assembly  28   a ,  28   b  bends the piece of wire  36  into a 90 degree or right angle. Then, each lower bending assembly  28   c ,  28   d , bends the piece of wire  36  into a 90 degree or right angle. Lastly, opposed ends of the piece of wire  36  are welded together using the welding unit  100  to complete the rectangle of the border wire  30 , as shown in  FIG. 1B . 
       FIG. 2  illustrates an enlarged portion of the apparatus  10 . A wire guide  40  extends outwardly from a portion of the support  38 . The wire guide  40  guides the finished border wires  30  onto a movable member (not shown) for transport. More specifically, the wire guide  40  extends forwardly from one of two holders  112  (the holder  112  on the left of  FIG. 3 ). Each holder  112  has a movable stop pin  114  driven by a cylinder, referenced in the flow chart of  FIG. 8 . The welded, completed border wire  30  is held in place for a moment using the stop pins  114  to allow the weld to cool before the border wire  30  is moved down the wire guide  40  to a product rack (not shown). 
       FIG. 2A  illustrates an enlarged view of the three-axis straightener  22  and the feed assembly  24 . The feed assembly  24  is driven by a servo motor  42 , which causes rotation of rollers or pullers  43  inside encasement  44 , best shown in  FIG. 2C . A piston  46  raises a rod  48  causing a cutter  50  to cut the wire  19  at the desired location. See  FIGS. 2B and 2C . 
       FIG. 3  illustrates a closer view of a portion of the wire support  38 . The wire support  38  comprises a stationary horizontal member  102  and a plurality of support member assemblies  52 , one of which is illustrated in  FIG. 3A . As shown in  FIGS. 3 and 3D , accordion-like or scissors-like adjusters  54  enable the support member assemblies  52  outside the upper bending assemblies  28   a ,  28   b  to move closer together or further apart. As best shown in  FIG. 3D , each adjuster  54  connects a plurality of support member assemblies  52 , the guides  53  of the support member assemblies  52  moving along rails  55  of the stationary horizontal member  102  of wire support  38 . 
     As illustrated in the drawings and described below, rotation of an upper drive rod  84  by a servo motor  104  (seen in  FIG. 3 ) causes movement of the two upper bending assemblies  28   a ,  28   b  during the set-up procedure. Because at least one of the support member assemblies  52  is connected to each of the upper bending assemblies  28   a ,  28   b , movement of the upper bending assemblies  28   a ,  28   b  causes movement of the accordion-like or scissors-like adjusters  54  to accommodate different wire lengths. Upper bending assembly  28   a  is connected to one of the support member assemblies  52  and, therefore, one of the accordion-like or scissors-like adjusters  54  (the one on the left as shown in the drawings). Similarly, upper bending assembly  28   b  is connected to one of the support member assemblies  52  and, therefore, one of the accordion-like or scissors-like adjusters  54  (the one on the right as shown in the drawings). Because the upper drive rod  84  has threads going in opposite directions (left and right hand threads), rotation of the upper drive rod  84  causes the upper bending assemblies  28   a ,  28   b  along with the attached adjusters  54  to move in opposite directions (apart or together), depending on the size of border wire desired to be produced. 
       FIG. 3A  illustrates a support member assembly  52  having a cylinder  56 , which moves a rod  58  in order to drop the wire  19  from inside a passage  60 . The passage  60  is defined between two blocks  62 ,  64 . Block  62  is stationary, and block  64  is movable. As shown by arrow  66  in  FIGS. 3A and 3B , a movable section  68  of the support member assembly  52  pivots about a pivot axis  70  when the rod  58  is pulled upwardly by the cylinder  56 . When the movable section  68  of support member assembly  52  is pivoted about axis  70  to a raised position in multiple support member assemblies  52 , the piece of wire  36  having a rectangular cross-section drops downwardly, as shown by arrow  72  of  FIG. 3B . Of course, the movable section  68  of support member assembly  52  may be pivoted about axis  70  to a lowered position in multiple support member assemblies  52 , in order to lock the piece of wire  36  having a rectangular cross-section in place. 
       FIGS. 3C, 3D and 3E  illustrate bending assembly  28   a . Each of the bending assemblies has the same parts, but they are oriented differently. Bending assembly  28   a  comprises a stationary radial die  74  and a movable bender subassembly  76 , including a roller  78  which moves in the direction of arrows  80  (counterclockwise). The bender subassembly  76  is driven by a servo motor  82 . After the piece of wire  36  is clamped in place with clamp  79 , the roller  78  engages the piece of wire  36  and bends it 90 degrees around stationary radial die  74 .  FIG. 3D  also illustrates several of the support member assemblies  52 , the piece of wire  36  being shown in phantom. 
     The wire  19  goes through the feeder  24  that feeds the programmed amount of wire for a select product code. At this point, the wire will be cut using cutter  50  just after the wire  19  is clamped at the upper bending assemblies  28   a ,  28   b . As the wire goes through the feeder  24 , it is fed through the guides that help insure it follows the correct path and goes through each of the two upper bending assemblies  28   a ,  28   b . Once the correct length is reached and the wire is through both of the upper bending assemblies  28   a ,  28   b , it is clamped and then cut using cutter  50 . The bending heads  78  then bend the wire around the radial dies  74 ; bending continues on so that the wire is fed into the lower bending assemblies  28   c ,  28   d . As the upper dies complete their bend of the wire, the wire is clamped into the lower bending dies and then bent again so that the wire has taken the “border” shape of the product code required. After the lower bending assemblies  28   c ,  28   d  have completed bending the wire, the ends of the wire are placed into the welding unit or welding head. Once in the welding head, the weld clamps close to hold the wire, and “squeeze” cylinders fire to force the two ends together while simultaneously firing current through the wire and forming a “butt weld” at the junction of the two ends. During this process, the upper dies release the wire, and “pushers” fire to push the wire out of the path of the next oncoming wire, so the process may repeat. Once welded, the weld ejects fire to also push the now finished product out of the way of the next incoming wire from the upper bending assemblies. The finished product slides forward to two stop pins, which hold the product until the next product is complete, allowing the weld to cool slightly before releasing it to slide down the wire guide  40  to a product rack (not shown). 
       FIG. 3C  shows bending assembly  28   a  movable on a rotatable threaded upper drive rod  84  driven by a servo motor  104  (shown in  FIG. 1B ). The drive rod  84  also passes through an upper block  88  of bending assembly  28   b  in the same fashion. A guide rail  86  passes through bottom blocks  90  of bending assembly  28   a , as shown in  FIG. 3C . The same is true for bending assembly  28   b . Thus, rotation of upper drive rod  84  moves the bending assemblies  28   a ,  28   b  closer together or further apart depending upon the direction of rotation of the drive rod  84 . 
       FIG. 1B  shows bending assemblies  28   c ,  28   d  movable on a rotatable threaded drive rod  92  driven by a servo motor  94  in the same manner. In the same manner shown in  FIG. 3B  with respect to upper bending assembly  28   a , drive rod  92  passes through an upper block  93  of each lower bending assembly  28   c ,  28   d  in the same fashion. Similarly, a guide rail  96  passes through bottom blocks  98  of each lower bending assembly  28   c ,  28   d , as shown in  FIG. 4 . Thus, rotation of drive rod  92  moves the lower bending assemblies  28   c ,  28   d  closer together or further apart depending upon the direction of rotation of the drive rod  92 . Because the lower drive rod  92 , like upper drive rod  84 , has threads going in opposite directions (left and right hand threads), rotation of the lower drive rod  92  causes the lower bending assemblies  28   c ,  28   d  to move in opposite directions (apart or together), depending on the size of border wire desired to be produced. 
       FIG. 4  illustrates the bottom bending assemblies  28   c  and  28   d  along with the welding unit  100 .  FIGS. 5, 5A and 5B  illustrate enlarged views of the bending assembly  28   c.    
       FIGS. 6, 6A, 6B and 6C  illustrate enlarged views of the welding unit  100 .  FIG. 6A  illustrates one of two weld eject cylinders  116  referenced in the flow chart of  FIG. 8 . The weld eject cylinders  116  pivot V-shaped members  118  to move the completed border wire  30  forwardly to cool before being passed along wire guide  40 . 
       FIG. 7  illustrates a servo motor  106  which, when activated, may raise or lower the lower bending assemblies  28   c ,  28   d  and the welding unit  100 . The servo motor  106  drives a drive train, which causes rotation of two vertical drive rods  108  (only one being shown in  FIG. 7 ). Rotation of vertical drive rods  108  moves the lower drive assembly  110  up or down depending upon the direction of rotation. 
     While the invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broadest aspects is not limited to the specific details shown and described. The various features disclosed herein may be used in any combination necessary or desired for a particular application. Consequently, departures may be made from the details described herein without departing from the spirit and scope of the claims which follow.