Patent Document

TECHNICAL FIELD 
   This application claims the benefit of U.S. Provisional Patent Ser. No. 60/492,931, filed Aug. 6, 2003, hereby incorporated by reference. The invention is generally directed to an apparatus and method for forming an adjustable duct member, and particularly to automatically rotating certain duct sections relative to other sections to form a finished adjustable duct member without the need for manual adjustment. 

   BACKGROUND OF THE INVENTION 
   In general, duct work is commonly used in forced air heating and air conditioning systems for buildings and the like. To facilitate installation of a duct work system, various types of duct members have been developed, including adjustable duct members such as elbow ducts. Elbow ducts typically have a plurality of sections which are independently adjustable relative to one another to form the duct member into a variety of configurations. The adjustability of the elbow allows flexibility in connecting duct systems in a desired manner. Each of the sections of the elbow duct member are coupled to adjacent sections by means of a connective fitting, which allows relative rotation between the sections. In the manufacture of such duct members, the duct is originally manufactured in a straight tubular construction, with the individual sections or gores of the adjustable duct member not being rotated relative to one another. Subsequent to manufacture, and for commercial sale, a worker is required to manually rotate the independent sections or gores of the duct member relative to one another to form the duct into the elbow configuration. With automatic elbow machines capable of producing thousands of elbows per day, such a process is labor intensive, and requires a constant repetitive motion, which can result in repetitive motion injuries such as carpal tunnel syndrome. It would therefore be desirable to provide in conjunction with the automated manufacture of a duct member, the ability to form the duct member into a final configuration for commercial sale, without requiring the foregoing manual operation. 
   SUMMARY OF THE INVENTION 
   Based upon the foregoing, the present invention is directed at an apparatus and method for forming a duct member, wherein the duct member has a plurality of adjustable sections which are rotatable relative to one another. In the manufacture of the duct member, the apparatus causes relative rotation between individual sections during the manufacturing process, to form a completed duct member in an automated process. These and other advantages are provided by a rotating head assembly for an automatic adjustable duct machine comprising: a rotating head body; a slide block having a cutting wheel and a beading wheel thereon, wherein the slide block is moveable within the head body to selectively extend one of the cutting wheel and the beading wheel radially outward from the rotating head body; and a plurality of engagement members extendable radially outward of the rotating body in an engagement position and retractable radially inward to a disengagement position. Other objectives and advantages of the invention will become apparent from the following description, taken in conjunction with the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of a workpiece for use in the apparatus of the present invention in making an adjustable duct member in accordance with the present invention; 
       FIGS. 2–8  are side elevational views of different intermediate stages of making an adjustable duct member in accordance with the present invention; 
       FIG. 9  is a side elevational view of a finished adjustable duct member as removed from the apparatus of the present invention; 
       FIG. 10  is a side elevational view of a prior art finished adjustable elbow as removed from a prior art automatic elbow machine; 
       FIG. 11  is a plan view of an apparatus for forming an adjustable duct member in accordance with the present invention; 
       FIG. 12  is a side view of the apparatus as shown in  FIG. 11 ; 
       FIG. 13  is a top view of the apparatus as shown in  FIG. 11 ; 
       FIG. 14  shows a partial sectional view of the upper plate and die assembly of the apparatus as shown in  FIG. 11 ; 
       FIG. 15  shows a partial sectional view of the roller assembly of the cutting and forming assembly as shown in  FIG. 16 ; 
       FIG. 16  shows a partial sectional view of the cutting and forming head assembly including the interior tube gripping means of the apparatus as shown in  FIG. 11 ; 
       FIG. 17  shows a sectional view of the cutting and forming head assembly showing the hydraulic system for actuating the interior tube gripping means; 
       FIG. 18  shows a sectional view of the cutting and forming head assembly showing the biasing system for retracting the interior tube gripping means; and 
       FIG. 19  is a perspective view of the clamp assembly associated with the base plate as shown in  FIG. 12 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Turning now to  FIGS. 1–9 , the invention is directed at producing an adjustable duct member such as shown in  FIG. 9 , wherein the adjustable duct member  20 , shown herein as a ninety degree adjustable elbow, from a workpiece  30  or blank as shown in  FIG. 1 , with intermediate steps shown in  FIGS. 2–8 , discussed in detail below. Referring to  FIG. 9 , the final automatically produced duct member  20  comprises a plurality of sections or gores  22 ,  24 ,  26 , and  28 . The gores  22 ,  24 ,  26 , and  28  are rotatably connected to their adjacent members by adjustable seams  23 ,  25 , and  27  also referred to as coupling beads. Seams  23 ,  25 , and  27  are formed at a 15 degree angle such that rotation of adjacent gores can result in an angle between zero (as initially formed) and thirty degrees (when rotated one hundred eighty degrees). As shown, the adjacent gores  22 ,  24 ,  26 , and  28  are at an angle of thirty degrees with their adjacent members to form a ninety degree adjustable elbow  20 . The duct member  20  further comprises an inlet opening  21  and an outlet opening  29 , being adapted to be coupled between other members in a duct system associated with the air handling system. 
   As shown in  FIG. 1 , the duct member  20  maybe produced from a flat blank of material which is rolled such that opposed seams of the blank slightly overlap and are coupled to one another to form the tubular blank workpiece configuration  30 . Coupling at the overlapping seams may be provided in any suitable manner, such as by riveting  32  or the like. As an example, the tubular configuration  30  of the formed blank of material may provide a starting work piece  30  which may then be operated on by the apparatus and methods of the invention. The work piece  30  is designed to have a predetermined configuration and dimensional characteristics for use in the apparatus and methods of the invention, but any suitable particular dimensional characteristics of the work piece can be accommodated. The apparatus and methods of the invention will take the work piece as shown in  FIG. 1  and produce adjustable seams or beads  23 ,  25 , and  27  in the work piece as depicted in  FIGS. 2–8  to form the duct member  20  in the final preferred form as shown in  FIG. 9 . In contrast, existing automatic elbow machines will produce a final article X as shown in  FIG. 10  and requiring manual rotation A, B, C of each gore by an operator to form a 90 degree elbow. 
   Turning now to  FIGS. 11–13 , an embodiment of the apparatus according to the present invention is shown in more detail. The apparatus generally designated  50  includes a housing or frame construction  52  which supports various components of the apparatus. Housing or frame  52  includes an upper surface  54  which is preferably defined by a floating support plate  56  which is adjustably mounted to the frame  52 . The upper support plate  56  is angled at a predetermined angle relative to horizontal or ultimately to the plane of one of the inlet or outlet openings  21 ,  29  associated with the work piece  30 , which is supported on a base plate provided as a part of an operating nest arrangement to be more fully described hereafter. Providing plate  56  with some adjustability allows an operator to adjust this predetermined angle to produce a predetermined component as desired. The plate  56  may be held in position by a plurality of support fasteners  58  or other suitable devices. The upper surface  54  of the apparatus  50  may include a work station or nest generally designated  60  which is formed as a recess adapted to accept the work piece  30  discussed in previous figures to perform the operations for cutting and forming the adjustable seams between gores of the work piece. 
   The nest  60  can include a die supported on the upper surface, which in the first embodiment may be comprised of first and second semicircular members  64  and  66  which are positioned on opposed sides of the nest  60 . The die members  64  and  66  are positioned immediately adjacent the nest  60  in operation, but may be moved into a non-operational position away from the nest  60  when desired in a manufacturing cycle. Therefore, each of the die members  64  and  66  may be supported in association with a slidable plate  68  and  70  which is supported in sliding engagement with support blocks  72  and  74  in a channel or slot  76 . The support block  74  may be adjusted relative to the plates  68  and  70  for smooth slidable operation of the plates within slot  76 . Each of the plates  68  and  70  may be moveable toward and away from the nest  60  by means of a hydraulic ram  77  or other suitable mechanism. Within the nest  60 , a cutting and forming system  80  is provided in the recessed portion of the nest  60 . Between the die members  64  and  66  and the cutting and forming system  80 , a circular channel  82  is formed by the recess of the nest  60 , the channel  82  being dimensioned to accept the work piece  30  (shown in  FIG. 1 ), with the work piece  30  extending into the channel  82  to a predetermined depth. Associated with the nest  60  is a base plate  88  at the bottom of channel  82  on which the work piece is supported within the nest  60  at the predetermined position. The base plate  88 , also referred to as the tube holding plate, includes a means (not shown) for clamping the work piece  30  to the base plate  88  to help prevent the work piece from rotating during cutting and forming operations and to couple the work piece  30  to the base plate  88  when the base plate  88  is rotated as discussed in detail below. Referring to  FIG. 19 , the base plate  88  has a clamp assembly  200  mounted thereto comprising a base ring  202  having an upwardly turned tubular extension  204  along and interior diameter thereof. The interior diameter of extension  204  provides clearance for support block  142  which will be discussed in detail below. The outer diameter of extension  204  is of a predetermined size such that either the inlet end  21  or outlet end  29  of work piece  30  fits over the extension  204  and is positioned a predetermined depth by contact with the top surface  206  of base ring  202 . Clamp assembly  200  also comprises a clamp ring  208  mounted and affixed to the top surface  206  of base ring  202 . Clamp ring  208  has an interior diameter larger than the outer diameter of extension  204  such that the channel  82  is formed allowing clearance for the insertion of one of either the inlet end  21  or outlet end  29  of work piece  30 . The clamp ring  208  comprises one or more clamp members  210  which are hydraulically or electrically actuated by one or more corresponding pistons  212 . The clamp members  210  are generally oriented perpendicular to extension  204  and parallel to the top surface  206  of base ring  202 . The clamp members  210  are generally shown herein as cylindrical members having a gripping irregular surface  211  on one end thereof. The piston  212  is connected to a piston ring  214  which moves upward and downward within clamp ring  208 . The piston ring  214  has an angled surface  216  along and interior diameter surface thereof. The angled surface  216  engages an angled surface  218  on clamp member  210 , on an end opposite the gripping irregular surface  211 , such that upward movement of piston ring  214  forces the clamp member  210  inward against the wall of work piece  30 , and against extension  204 . The work piece  30  is securely held in place by the gripping irregular surface  211  as cutting and forming operations are perform thereon as will be discussed in detail below. The gripping pressure can be increased by adding additional pistons/gripping members. Although a specific clamping means is shown and described, the invention is not limited to a particular clamping system. The clamping means may be of any known clamping apparatus, however, it is preferred that the clamping means disclosed in U.S. Pat. No. 6,378,184, hereby incorporated by reference, are utilized. Referring again to  FIGS. 11–13 , the base plate  88  is formed in association with a moveable platen  84  which is operated on by a pair of hydraulic rams or other suitable mechanism to selectively move platen  84  upwardly or downwardly with respect to the housing and other components of the apparatus  50 . The moveable platen  84  preferably carries at its upper end the base plate  88 , with a drive plate  90  at the bottom end thereof. The central portion  92  of platen  84  is a cylindrical portion extending between plates  88  and  90 . The plates  88  and  90  each have apertures coinciding with the cylindrical portion  92  to define a hollow interior through which a drive shaft arrangement  94  is positioned. The drive shaft system  94  is coupled to be driven by a hydraulic motor  96  supported in association with housing  52 . The platen assembly  84  is moveable about the drive shaft assembly  94  upwardly and downwardly to selectively position a work piece  30  relative to the die members  64  and  66  and the cutting and forming system  80 . 
   The apparatus  50  also preferably includes a control system generally designated  110 , which may be any suitable system such as a microprocessor or PLC based system, to selectively perform the various operations and steps to produce the duct member  20  according to the methods of the invention. Preferably, control system  110  can be designed to automatically perform various operations in a manufacturing sequence to produce a particular type of duct member  20 . Each different type of duct member will effectively have a process sequence recipe that can be simply recalled using the control system  110 , with subsequent automated performance of each step in the manufacture of the duct member  20 . In this way, an unskilled operator can simply recall a particular recipe for the type of duct member to be produced, alleviating the necessity for a skilled operator and simplifying the manufacturing process. 
   Turning now to  FIG. 14 , the top plate assembly and associated die members and are shown in more detail. The die members  64  and  66  as previously described are designed to cooperate with one another to form when positioned adjacent the work piece a stationary form into which material of the work piece is pushed by the cutting and forming system  80 . Preferably the die members  64  and  66  are formed to include a recess, which will cooperate with a portion of the forming system  80  to generate an outwardly directed bead in the work piece of substantial depth. It is pointed out that, die members  64  and  66  also perform a clamping function in addition to the forming function of the die. This enables both cut sections to be properly secured during and after the cutting and forming operation. Below the forming section of the die, a separate plate  132  may be provided with an outwardly extending knife edge  134  which is designed in cooperation with the cutting and forming assembly to cut the work piece at the desired position. The cutting plate, or ring  132 , is fixably attached to the die members  64  and  66 . Providing the knife as a separate member  132  facilitates maintenance of the apparatus, as it is possible for the knife or knife edge to become damaged, simplifying replacement of the plate  132  without impact on the forming section of the die formed by die member  64  and  66 . The particular shape of the forming portion or knife portion of the die may be modified to produce a desired coupling bead configuration other than that shown in the preferred embodiment. 
     FIGS. 15 and 16  refer to a first embodiment of the cutting and forming assembly  80  of the invention. In  FIG. 11 , the cutting and forming assembly may comprise a head portion  140  including a supporting block  142  carrying a rotating working head  144  shown in section. The drive shaft  94  driven by motor  96  is positioned to extend through the support block  142  and is coupled to the working head  144  for selective rotation thereof. The working head  144  includes a moveable slide block  146  mounted within a slot  147 , having a cutting wheel  148  at one end thereof and a beading wheel  149  on the other end. The slide block  146  is moved back and forth to provide cutting and beading steps successively, with each of the wheels  148  and  149  being successively exposed to perform these operations as the head  144  rotates. The back and forth motion of the slide block  146  within slot  147  is created by an eccentric drive shaft  151  mounted in the center of the working head  144 . The eccentric shaft  151  includes an eccentric drive head  145 . An off-center pin  150  associated with the eccentric drive head  145  is engaged in a slot in the bottom of the slide block  146  which moves the slide block  146  within slot  147  so as to selectively expose one of the wheels  148  or  149  as the head  144  rotates. To cut and preform the workpiece, the slide block  144  is initially centered within slot  147 , and the cutting wheel  148  is then moved out into engagement with the interior of the work piece, and cooperates with the knife edge on the stationary die member as previously described to cut the work piece. To couple the cut portions, the slide block  146  moves to expose the beading wheel  149  after the cut pieces of the tube are positioned in overlapping relationship. In cooperation with the stationary die member, the bead coupling is formed. 
   The head portion  140  further comprises a means  160  for engaging the interior of the workpiece such that the cut portion of the workpiece is able to be rotated one hundred eighty degrees with respect to the remaining workpiece as described in detail below. As shown, means  160  comprises a plurality of fingers  162  extendable radially outward from the head  140 . The fingers  162  are shown to be activated by hydraulic pressure through internal hydraulic line  164 . If necessary, the gripping pressure can be increased by adding additional fingers/gripping members  162 . When the pressure is released, a biaser  166  shown herein as a spring, forces each finger  162  radially inward to a position disengaged from the interior of the workpiece.  FIGS. 17 and 18  show cross-sections of the head highlighting the hydraulic passages which activate the fingers  162  and the biaser  166  connections which retract the fingers  162 , respectively. 
   The method of the present invention is now discussed in detail with reference to  FIGS. 1–9  showing the stages of production of the workpiece and the apparatus  50  as shown in  FIGS. 11–17 . The starting work piece  30  ( FIG. 1 ) is placed into the channel  82  of the nest  60  of apparatus  50 . The bottom of work piece  30  is secured by the clamping means of the tube holding plate to prevent unintentional rotation of the work piece  30 . The cutting and forming assembly  80  performs the first cut and preform to the work piece  30  as previously described in association with the dies  64 ,  66 , forming a first gore  22  or upper tube and the remaining work piece  30 A or lower tube ( FIG. 2 ). (At this point the dies  64 ,  66  may need to be slightly retracted). The tube holding plate will lift the lower tube  30 A slightly into upper tube  22 . The fingers  162  on the head are hydraulically actuated to engage the inside of the upper tube  22  to provide a means of holding the upper tube  22 . The head then rotates the upper tube  22  one hundred eighty degrees (it is also contemplated that the head  140  may remain stationary and that the tube holding plate may rotate the lower tube  30 A by one hundred eighty degrees) and then the fingers  162  are disengaged as previously described. The tube holding plate then elevates the lower tube  30 A into the upper tube  22  a sufficient amount to form a coupling bead. (At this point the dies are again extended if previously retracted) The cutting and forming assembly  80  then forms the coupling bead  23 . At this point ( FIG. 3 ), the longitudinal axis of the first gore  22  is approximately thirty degrees transverse to the remaining work piece  30 A. The tube holding plate then rotates the work piece  30  one hundred eighty degrees and elevates the work piece  30  to a second cutting position ( FIG. 4 ). 
   The cutting and forming assembly  80  performs the second cut and preform to the work piece  30 , forming a second gore  24  below the first gore  22 , and above the remaining work piece  30 B or lower tube ( FIG. 5 ). The tube holding plate will lift the lower tube  30 B slightly into second gore  24 . The fingers  162  on the head  140  are hydraulically actuated to engage the inside of the second gore  24  to provide a means of holding the second gore  24 . The head  140  then rotates the second gore  24  (and the attached upper gore  22 ) one hundred eighty degrees and the fingers  162  are disengaged. The tube holding plate then elevates the lower tube  30 B into the second gore  24  a sufficient amount to form an adjustable seam. The cutting and forming assembly  80  then forms the adjustable seam  25 . At this point ( FIG. 6 ), the longitudinal axis of the second gore  24  is approximately thirty degrees transverse to the longitudinal axis of the remaining tube  30  B and approximately thirty degrees transverse to the longitudinal axis of the first gore  22 . The tube holding plate then rotates the work piece  30  by one hundred eighty degrees to a third cutting position ( FIG. 7 ). 
   The cutting and forming assembly  80  performs the third cut and preform to the work piece  30  forming a third gore  26  and a fourth gore  28  or lower tube ( FIG. 8 ). The tube holding plate will lift the fourth gore  28  slightly into the third gore  26 . The fingers  162  on the head  140  are hydraulically actuated to engage the inside of the third gore  26  to provide a means of holding the third gore  26 . The head  140  then rotates the third gore  26  (and the attached first and second gores  22 ,  24 ) one hundred eighty degrees. The tube holding plate then elevates the fourth gore  28  into the third gore  26  a sufficient amount to form an adjustable seam. The cutting and forming assembly  80  then forms the adjustable seam  27 . At this point ( FIG. 9 ), the longitudinal axis of the third gore  26  is approximately thirty degrees transverse to the longitudinal axis of the fourth gore  28  and approximately thirty degrees transverse to the longitudinal axis of the second gore  24  such that the work piece  30  has now been converted into a ninety degree elbow  20  without requiring any manual rotation of the gores  22 ,  24 ,  26 ,  28 . The finished duct member  20  is then removed from the apparatus  50  and the process is repeated. 
   Although the present invention has been shown to produce a duct member in the form of a standard, four-gore, ninety degree elbow, any duct member having adjustable gores formed at any angle is contemplated. Embodiments of this invention can be directly applied in other forming machines such as those described in U.S. Pat. No. 6,378,184 and U.S. Pat. No. 6,105,227, hereby incorporated by reference. While the above description has been presented with specific relation to a particular embodiment of the invention and methods of producing a specific adjustable duct member, it is to be understood that the claimed invention is not to be limited as such and that certain changes may be made without departing from the scope of the invention with the above description intended to be interpreted as illustrative and not limiting.

Technology Category: 4