Abstract:
A finishing apparatus for ductwork having a duct body with at least one open end. The finishing apparatus includes an operation platform for selectively supporting the ductwork and a first wrapping mechanism integrated with the operation platform, the first wrapping mechanism including a first dispenser for dispensing a first film. The finishing apparatus further includes a first cutting mechanism integrated with the first wrapping mechanism. In operation, the first wrapping mechanism selectively dispenses the first film adjacent to and against the open end of the ductwork as the ductwork is moved a predetermined distance down the operation platform. The first cutting mechanism selectively cutting the first film after the ductwork has moved the predetermined distance down the operation platform.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application Ser. No. 61/528,344, filed on Aug. 29, 2011, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to ventilation equipment and, more particularly, to packaging and storage of ventilation duct sections. 
     BACKGROUND OF THE INVENTION 
     Ventilation ducts are manufactured as open-ended sections or segments of sheet metal tubing in profiles of various shapes. Typically the ends of the duct sections have flanges. The duct sections frequently are stored in warehouses before being shipped to a final install destination. During warehouse storage, and in transit on open trucks or railcars, it is possible for debris or pests to enter the open ends of the duct sections. 
     To prevent entry of debris or pests, the open ends of duct sections can be covered. Cling wrap or similar film (“duct wrap”) is often used for this purpose. Manual application of duct wrap is labor intensive and also is surprisingly hard to accomplish without tearing or gapping the duct wrap in a manner that would render the whole exercise pointless. 
     Accordingly, it is desirable to have a machine or apparatus that will provide for easier attachment of duct wrap onto manufactured ventilation ducts. 
     SUMMARY OF THE INVENTION 
     According to the present invention, a duct wrap dispenser is provided for attaching duct wrap onto the open ends of a ventilation duct section. The duct wrap dispenser includes a roller conveyer for supporting each duct section in a vertical posture, and also includes a frame surrounding and extending above the roller conveyor. The roller conveyor supports a lower wrapping tool that includes two pivotal roller assemblies, vacuum tubes, and a lower cut-off knife. The frame supports an upper wrapping tool that includes an upper wrap supply, vacuum tubes, an upper applicator, and an upper cut-off knife. The vacuum tubes hold the duct wrap in position to receive and contact each duct section as it moves along the roller conveyor. The applicators press the duct wrap against the open ends of the duct section, ensuring adhesion of the duct wrap to the duct section. The cut-off knives sever the duct wrap after the duct section has moved through the wrapping tools and has been fully wrapped. 
     These and other objects, features and advantages of the present invention will become apparent in light of the detailed description of the best mode embodiment thereof, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows in perspective the exit side of a duct wrap dispenser including a conveyor housing a lower wrapping tool and a standing frame supporting an upper wrapping tool, according to an embodiment of the present invention. 
         FIG. 2  shows a hinged sub frame portion of the conveyor shown in  FIG. 1 , swung up to render a slid-in core support accessible for loading a roll of duct wrap film. 
         FIG. 3  shows the swing-up sub-frame in its normal retracted position, ready for use with the duct wrap film routed across the lower wrapping tool. 
         FIGS. 4 through 6  show the lower wrapping tool including a pivot assembly with foot operated levers for moving a sponge applicator from a recessed position to a deployed position for adhering the duct wrap film to the leading side of a duct section. 
         FIGS. 7 through 9  show the lower wrapping tool, with the applicator pivoting to its deployed position for pressing the duct wrap onto the leading surface of the duct section. 
         FIGS. 10 through 12  show another embodiment of the lower wrapping tool including a broom applicator in place of a sponge. 
         FIGS. 13 through 15  show the duct section exiting the lower wrapping tool across a slicing apparatus that includes vacuum tubes and a cut-off knife housed between the vacuum tubes. 
         FIG. 16  shows the cut-off knife severing the duct wrap after the trailing surface of the duct section. 
         FIG. 17  shows the cut-off knife extended upward between the vacuum tubes. 
         FIG. 18  shows a schematic of a wavy knife blade used in the cut-off knife. 
         FIG. 19  shows in detail a pull pin for adjusting a height of the standing frame shown in  FIG. 1 . 
         FIG. 20 through 22  show entry and exit views of an upper wrapping tool mounted on the standing frame, including an upper wrap supply, an applicator roller, and an upper slicing apparatus. 
         FIG. 23  shows a swing in core support used in the upper wrap supply. 
         FIG. 24  shows the duct section entering the upper wrapping tool. 
         FIG. 25  shows the duct section exiting the upper wrapping tool. 
         FIG. 26  shows the upper slicing apparatus severing the duct wrap after the trailing surface of the duct section. 
         FIGS. 27-29  show further steps in applying duct wrap to the duct section. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       FIG. 1  shows a duct wrap dispenser  100 , according to one embodiment of the present invention. The duct wrap dispenser includes a roller conveyor  102  and a standing frame  104  mounted to the roller conveyer, and is shown from the exit end of the roller conveyor. A small duct section or segment  10  is shown at the entry end of the duct wrap dispenser, ready to move through the dispenser. 
     In the disclosed embodiments of the invention, the rollers  106  of the conveyor  102  are non-powered, and the duct section  10  is pushed by an operator along the conveyor. Alternatively, powered rollers could be used. By incorporating a programmable logic controller (PLC) and position sensors such as photo eyes or finger switches, a completely automated embodiment of the invention could be provided, as will be apparent to those of ordinary skill after reviewing the following detailed description. 
     The roller conveyor  102  includes a plurality of rollers  106  mounted on fixed axles, as well as a lower wrapping tool  108  mounted between the conveyor frame rails  110  at a middle region of the conveyor. Proceeding from the entry end of the dispenser  100 , the lower wrapping tool  108  includes a swing-up hinged sub frame  112 , then a pivot assembly  114 , and finally a slicing apparatus  116  that includes two or more vacuum tubes  118 , with a cut-off knife housed between the first and second vacuum tubes. 
     Referring to  FIG. 2 , the hinged sub-frame  112  includes a duct wrap supply  120  for the lower wrapping tool  108 , and a roller  122  that is normally disposed above the duct wrap supply. In case the lower wrapping tool runs out of duct wrap, the hinged sub-frame is mounted to the conveyor frame rails  110  on spring centered hex axles  124 . These axles permit the hinged sub-frame to swing up from the conveyor rails to an extended position where the lower wrap supply is accessible for reloading with a full roll of duct wrap film. The lower wrap supply is shown to include a slide-in support rod  126  for the roll of duct wrap, however, other supports are within the scope of the invention as further discussed with reference to  FIG. 23 . 
     When the duct wrap film is loaded onto the lower wrap supply  120  in the hinged sub-frame  112 , it is pulled across the pivot assembly  114  and the slicing apparatus  116  toward the exit end of the conveyor, as shown in  FIG. 3 . Generally, the rollers  106  have polished metal surfaces to which the duct wrap does not adhere. However, in the pivot assembly one roller  128  is coated with rubber or equivalent material that will adhere to the duct wrap. The duct wrap contacts this rubber covered roller, which helps to hold the duct wrap in position after it is sliced as further discussed below. 
       FIGS. 4 through 6  specifically show the pivot assembly  114 , which is disposed at the exit side of the hinged sub-frame  112 . The pivot assembly includes the normally-upwards rubber covered roller  128  to which the duct wrap lightly adheres. The pivot assembly also includes a normally-recessed applicator  130  at the exit side of the rubber roller. As shown in  FIGS. 4 through 6 , the applicator may be formed from a sponge material sufficiently soft to generally conform to an outer surface of the duct section  10 , when the applicator is in a deployed position above the conveyor rollers  106 . Foamed polymers also could be used for the applicator sponge. 
     As mentioned, the pivot assembly  114  is movable from a normal or retracted position to a deployed position. In the embodiment shown in  FIG. 4 , the pivot assembly includes a pedal  132  with which an operator can pivot the assembly to bring the applicator  130  from its normal retracted position to its deployed position above the rollers  106  of the conveyor  102 . Alternatively, the pivot assembly can be automatically actuated by the duct section  10  triggering a photo eye, finger switch, or the like. 
     In any case, as shown in  FIGS. 7 through 9  the pivot assembly  114  can be pivoted from its normal retracted position where the applicator  130  is recessed below the conveyor rollers  106  to a deployed position where the applicator is exposed above the conveyor  102  to press duct wrap against the leading surface of a duct section  10 . In some embodiments, the pivot assembly is biased to its normal retracted position by a spring or the like (not shown). 
       FIGS. 10 through 12  show another embodiment of the pivot assembly  114 , in which a soft brush is used for the applicator  130 . 
     Referring to  FIG. 13 , after passing over the pivot assembly  114 , the duct section  10  carries the duct wrap across the slicing apparatus  116  disposed at the exit end of the lower wrapping tool  108 . The slicing apparatus includes at least two vacuum tubes  118  as discussed above. Each of the vacuum tubes includes a plurality of upward-opening holes through which vacuum can be applied to slidingly hold the duct wrap film against the tubes. The slicing apparatus also includes a thin and wavy knife blade  134  that is disposed between and extends along the first and second vacuum tubes. The knife blade is retractably operable, for example by a pneumatic cylinder  136 , to quickly slice through duct wrap held by the vacuum tubes. At least during the slicing operation, the vacuum tubes hold down the duct wrap so that the knife blade can slice diagonally upward through the duct wrap. 
     During operation of the disclosed embodiment, the vacuum tubes  118  provide continuous suction on the duct wrap, via arrays of vacuum nozzles  138  that are spaced apart along the tubes. The suction holds the duct wrap down against the tubes while permitting the duct wrap to slide across the tubes as the duct section  10  exits the lower wrapping tool  108 . Beyond the vacuum tubes, the duct section rolls to the exit end of the roller conveyor  100 . 
     The lower cut-off knife  134  is disposed after the first tube in the group of lower vacuum tubes  118 . As the trailing surface of the duct section  10  clears the vacuum tubes, the duct wrap extending from the duct section back to the lower duct wrap supply  120  is severed by the cut-off knife disposed between the vacuum tubes. In the disclosed embodiment, the cut-off knife is manually triggered. Alternatively, the pneumatic piston  136  may be automatically triggered by a photo eye, by a finger switch, or the like. 
       FIGS. 14 and 15  show the duct section  10  moved across the slicing apparatus  116  with the duct wrap extending from the trailing surface of the duct section, across the slicing apparatus, to the wrap supply  120 . In particular,  FIG. 15  shows the vacuum tubes  118  sucking down the duct wrap.  FIG. 16  shows an upward slicing motion of the knife blade  134  through the duct wrap, which is still held down by the vacuum tubes.  FIG. 17  shows the severed duct wrap, with the knife blade still extended above the vacuum tubes. 
     As shown in  FIG. 18 , the knife blade  134  has a wavy edge  140 , and has two diagonal cam slots  142  formed in it. In the disclosed embodiment the blade is driven by a pneumatic cylinder and piston  136 . The piston is connected directly to the blade, and the cylinder is hingedly connected to the conveyor frame. The blade is mounted to the frame on pins that slide within the cam slots. Thus, as the piston is extended, the blade slices sideways and upward to sever the duct wrap. As the piston is retracted, the blade retracts sideways and downward, out of the path of the next duct segment. 
     Referring back to  FIG. 1 , the standing frame  102  extends upward from and surrounds the roller conveyor frame. The standing frame includes telescoping legs  144 , so that an upper bar or frame head  146  can be positioned to various heights by removing and replacing pull pins  148  from holes in the legs. The frame head height can be selected to match nominal lengths of duct segments, for example, four (4), five (5) or six (6) feet. One of the pull pins is shown in  FIG. 19 . 
     Referring to  FIGS. 1 and 20 , the frame head  146  supports the upper wrapping tool  150  generally in registry with the lower wrapping tool  108 . The upper wrapping tool includes an upper wrap supply  152  generally similar to the lower wrap supply  120 , an upper applicator  154 , a group of at least two vacuum tubes  118  substantially similar to the lower vacuum tubes, and a slicing apparatus  116  substantially similar to the lower slicing apparatus.  FIG. 20  shows in side perspective view the pneumatic cylinder  136 , knife  134 , and pivotal connections of the upper slicing apparatus as well as the vacuum tubes.  FIG. 21  shows the upper slicing apparatus in bottom perspective view to reveal the suction holes  138  of the vacuum tubes, which hold the duct wrap up so that the upper knife can slice through the duct wrap. 
     In the disclosed embodiment, the upper wrap supply  152  includes swing-in supports  156  (as shown in  FIG. 23 ) for a roll of duct wrap. When the roll of duct wrap is loaded onto the swing-in supports, the duct wrap hangs downward from the upper wrap supply across the entry side of the upper applicator  154 .  FIG. 22  shows a correct amount of duct wrap film hanging down ready for a duct section to be pushed under the soft rubber roller that composes the upper applicator. The duct wrap adheres somewhat to the rubber coating on the upper applicator roller. The duct wrap adheres more to the duct segment  10  than to the upper applicator. The roller applies light pressure against the upward open end of the duct section, causing the duct wrap to adhere to the duct section as shown in  FIG. 24 . 
       FIG. 24  also shows that, after the duct section  10  passes under the upper applicator  154 , the duct section drags the duct wrap across the upper slicing apparatus  116 . Suction from the vacuum nozzle  138  holds the duct wrap up against the slicing apparatus in a sliding manner, as shown in  FIG. 25 . Once the trailing surface of the duct section has passed the slicing apparatus, the upper knife pneumatic piston  136  is actuated to drive the knife  134  diagonally downward, severing the duct wrap as shown in  FIG. 26 . After the duct wrap has been severed, the end still attached to the upper wrap supply  152  drops away from the first upper vacuum tube and once again hangs down between the wrap supply and the upper applicator  154 . 
     After exiting the slicing apparatus  116 , the duct section  10  stands free at the exit end of the roller conveyor. The duct wrap then can be manually applied to surfaces, such as the side surfaces, that were not handled by the duct wrap dispenser. It will be appreciated that further modifications may be made to provide mechanical application of the duct wrap to the side surfaces of duct sections.  FIGS. 27 and 28  show steps of applying duct wrap that result in a fully-wrapped duct as shown in  FIG. 29 . 
     Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and the scope of the invention. 
     For example, as shown and described, the invention is usable to concurrently wrap both ends of a duct section; each wrapping tool also can be used individually. The disclosed embodiment is scaled for 24-inch duct widths, however, the invention may be adapted at least for use with 36 inch or 48 inch duct widths. Also, the duct wrap film may be made in a variety of colors and thicknesses by any of numerous manufacturers, and may be more or less adhesive depending on its composition.