Patent Publication Number: US-6981398-B2

Title: Seam closing apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/412,723, filed on Sep. 23, 2002, herein incorporated by reference in its entirety. 

   FIELD OF THE INVENTION 
   This invention relates in general to a seam closing apparatus, and deals more particularly with a seam closing apparatus, which is capable of closing seams in ductwork via one pair of closing rollers. 
   BACKGROUND OF THE INVENTION 
   Rectangular or box-shaped ducts are extensively utilized in heating and ventilating systems to distribute heated or cooled air throughout a structure. These ducts are commonly formed from differing gauges of sheet metal in sections of predetermined lengths, which are then connected to one another to form a continuous duct for distributing air. 
   Typically, each section of duct is formed by bending two pieces of sheet metal of the desired length at a 90° angle. One edge of each piece is formed to include a longitudinally extending groove, forming thereby the female portion of the seam, while the other longitudinal edge of each piece is bent over along its length to form thereby the male portion of the seam. The two pieces are then assembled by inserting the male portion of each piece into the female portion, leaving an edge extending beyond the joint from the female portion. This extended edge must then be bent over to lock the seam. One industry standard example of such a seam is a ‘Pittsburgh’ lock or seam. 
   A seam closing tool is utilized to complete the sealing process by bending over the extended edge of the female portion. Known seams, such as the Pittsburgh seam, include an extended edge which extends approximately perpendicularly to its final, sealed position. Consequently, the seam closing tool must employ a plurality of rollers to gradually bend, or form, the extended edge over to its final sealed position, each of the plurality of rollers bending the extended edge over to a greater degree until the final sealing position is attained. It is also known to utilize either a manual or pneumatically actuated hammer to bend or form over the extended edge of the female portion. 
   While these known sealing systems are successful to a degree, they suffer from several logistical problems. Firstly, the multi-roller seam closing tool cannot completely seal the entire length of a given seam at those locations adjacent the end of the seam. This inability to completely seam the length of the seam is due to the graduated sealing angles inherent in each of the plurality of rollers of the seam closing tool. That is, it is the last of the rollers which has the most severe sealing angle and accomplishes the final sealing operation of the seam closing tool, however the last roller is preceded by all of the other rollers and, therefore, will not be permitted to reach or affect the last few feet or inches of the seam. Hammering will thus be necessary to finish the complete seal of the seam. 
   Similarly, the manual or pneumatic hammering of the seam in its entirety is highly labor intensive and quite loud, oftentimes requiring ear protection for the operators who assemble the finished duct work. Moreover, the time and effort extended on hammering the extended edge of the female portion over to seal the seam, can substantially increase the time and expense of any duct fabrication and installation job, typically by as much as 50% or more. 
   With the forgoing problems and concerns in mind, it is the general object of the present invention to provide a seam closing apparatus which overcomes the above-described drawbacks while maximizing effectiveness and flexibility in the assembling process. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a seam closing apparatus. 
   It is another object of the present invention to provide a seam closing apparatus that can be utilized along the entire length of a duct seam. 
   It is another object of the present invention to provide a seam closing apparatus that utilizes only a single pair of driven rollers. 
   It is another object of the present invention to provide a seam closing apparatus that requires no hammering to completely seal a duct seam. 
   It is another object of the present invention to provide a seam closing apparatus that can assuredly track the length of a duct seam. 
   It is another object of the present invention to provide a duct fastseam that is capable of maintaining the duct in a substantially square condition even when the fastseam has yet to be completely sealed. 
   It is another object of the present invention to provide a seam closing apparatus that can be operated quietly and by a single person. 
   These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional view of a known duct seam. 
       FIG. 2  is a cross-sectional view of the male and female ends of a duct fastseam. 
       FIG. 3  is a partial cross-sectional view of a seam closing apparatus, according to one embodiment of the present invention. 
       FIG. 4  is a partial cross-sectional view of the seam closing apparatus shown in  FIG. 3  as it operates upon a duct seam. 
       FIG. 5  is a partial cross-sectional view of the seam closing apparatus as it engages the seam of a duct. 
       FIG. 6  is a partial cross-sectional view of the operation end of the seam closing apparatus shown in  FIG. 3 . 
       FIG. 7  is a cross-sectional view of the operation end of the seam closing apparatus taken along lines A—A. 
       FIG. 8  is a cross-sectional view of the operation end of the seam closing apparatus taken along lines B—B. 
       FIG. 9  is a planar view of a seam closing apparatus, according to another embodiment of the present invention. 
       FIG. 10  illustrates the seam closing apparatus of  FIG. 9  as it is first applied to a seam of a duct. 
       FIG. 11  illustrates the seam closing apparatus of  FIG. 9  as it is operated to seal the outwardly extending sealing portion of the seam. 
       FIG. 12  is a partial cross-sectional view of the seam closing apparatus of  FIG. 9  as it engages the seam of a duct. 
       FIG. 13  is a partial cross-sectional view of the operation end of the seam closing apparatus shown in  FIG. 9 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  illustrates a cross-sectional view of a known duct seam  10 , commonly referred to in the field as a ‘Pittsburgh’ seam. As shown in  FIG. 1 , the seam  10  includes a female portion  12  which is formed by repetitively bending, or roll forming, the duct material, typically sheet metal or the like, so as to form three substantially parallel folds  14 . The folds  14  serve to define a female groove  16 , wherein one of the folds  14  preliminarily extends beyond the duct edge to establish a sealing portion  18 . 
   The seam  10  further includes a longitudinal section of the duct wall  20  which is bent at a substantially right angle to form a male portion  22 . As will be appreciated, the male portion  22  is sized for tight fitting within the female groove  16  of the female portion  12  when fully assembled. 
   In operation, the male portion  22  of the seam  10  is initially fitted into the female groove  16  when the sealing portion  18  remains in its unsealed position, as represented by the dashed lines in  FIG. 1 . 
   Once the male portion  22  has been inserted into the female groove  16 , the sealing portion  18  must then be hammered or otherwise bent down, in the direction of the arrow A, against the duct wall  20  in order to complete the sealing of the seam  10 . The hammering over of the sealing portion  18  is typically accomplished either manually, or with the use of a pneumatic hammer or the like. It will be readily appreciated that the hammering of the male portion  22  and the sealing portion  18  is highly time consuming and oftentimes noisy to the point of being injurious to the ears of the operators who are assembling the seam  10 . 
   A known, multi-roller seam closing tool may also be utilized to close the seam  10 . As shown in  FIG. 1 , the sealing portion  18  must be bent, or formed, from its approximately perpendicular position (shown in dashed lines) to its sealed position and, therefore, a multitude of rollers are required to incrementally bend or form the sealing portion. As discussed previously, the utilization of such a multi-roller seam closing tool is unsatisfactory as manual or power-assisted hammering must still be employed to seal the last few feet or inches of the seam. 
   In contrast,  FIG. 2  illustrates the male and female portions of a fastseam  100  which is currently the subject matter of a co-pending application. As shown in  FIG. 2 , the fastseam  100  includes a male portion  124  inserted within a groove  106  of a female portion  102 . The female portion  102  further includes a sealing portion  120 , which will be bent in the direction of arrow B in order to seal the fastseam  100 . 
   Turning to  FIG. 3 , a partial cross-sectional view of a seam closing apparatus  200  is shown, according to one embodiment of the present invention. As shown in  FIG. 3 , the seam closing apparatus  200  includes a housing  202 , a power supply cord  204 , which may be either electrical or pneumatic in design, and an actuation trigger  206 . An operation end  208  is generally shown in  FIG. 3  and includes a pivot handle  210 , a drive roller  212  and a idler roller  214 . Owing partially to the configuration of the sealing portion  120  of the fastseam  100 , shown in  FIG. 2 , the seam closing apparatus  200  is capable of completely closing the fastseam  100  along its entire length without necessitating a hammering step or the like. 
     FIG. 4  illustrates the seam closing apparatus  200  as it is applied to the fastseam  100  of a length of duct  216 . As shown in  FIG. 2 , when pressure is applied to the pivot handle  210  in the general direction of the arrow P, the idler roller  214  will swing upwards in the general direction of the arrow S, thus capturing the fastseam  100  between the drive roller  212  and the idler roller  214 . The drive roller  212  will thereby flatten the partially angled sealing portion  120  under force of the engagement of the idler roller  214  and the operator&#39;s downward pressure of the housing  202 . 
   Once the seam closing tool  200  has engaged the fastseam  100 , the operator will then actuate the trigger  206  and cause thereby the drive roller  212  to rotate in the counterclockwise direction (as seen in  FIG. 4 ), propelling the seam closing tool  200  in the direction of arrow D while flattening the sealing portion  120  to its completely sealed position. It will be readily appreciated that the pivot handle  210  may be continuously biased in the direction of arrow P by the operator during operation or, alternatively, a latch may be formed so as to hold the pivot handle  210  in its engaging position. 
   It is therefore an important aspect of the present invention that the seam closing tool  200  utilizes only a single, driven roller  212  to bend or form the sealing portion  120  to its completely sealed position. Moreover, by employing only a single driven roller  212  which is not preceded by a plurality of additional, incremental rollers, the seam closing apparatus  200  of the present invention will permit the driven roller  212  to transverse and seal the entirety of the fastseam  100  without requiring the additional time, expense and audible discomfort of a hammering operation. 
     FIG. 5  illustrates an end view of the seam closing apparatus  200  as it is engaged with the fastseam  100 . As shown in  FIG. 5 , the idler roller  214  includes an annular groove  218  which serves to receive the lower bend  220  (also shown in  FIG. 2 ) of the fastseam  100 , thereby ensuring a secure lock upon, and tracking of, the fastseam  100  as the seam closing apparatus  200  is driven down the length of the fastseam  100 . 
   It should also be noted that the driven roller  212  includes an angled profile  222  such that, as shown in the cross-sectional view of  FIG. 5 , the circumference of the driven roller  212  is smaller in the area adjacent the seam closing apparatus  200  than it is at the exterior side  224  of the driven roller  212 . In this manner, the eccentrically formed driven roller  212  ensures a tight seal of the sealing portion  120  against the duct wall  216 . 
     FIG. 6  illustrates a partial cross-sectional side view of the operation end  208  of the seam closing apparatus  200 .  FIG. 7  illustrates the section A—A taken through the operation end  208 , while  FIG. 8  illustrates the section B—B taken through the operation end  208 . 
   While the seam closing apparatus  200  has been described as including a pivot handle  210  and a displaceable idler roller  214 , the present invention is not limited in this regard. Alternative embodiments of the present invention are envisioned to include a seam closing apparatus having no pivot handle  210 , having instead only an idler roller which is fixed in position with respect to the driven roller  212 . In this embodiment, an operator need only depress the driven roller  212  onto the sealing portion  120  until the groove  218  of the idler roller is capable of latching onto the lower bend  220  of the fastseam  100 . 
   Turning to  FIG. 9 , a side plan view of a seam closing apparatus  300  is shown, according to another embodiment of the present invention. As shown in  FIG. 9 , the seam closing apparatus  300  includes a housing  302 , a power supply cord  304 , which may be either electrical or pneumatic in design, and an actuation trigger  306 . An operation end  308  is generally shown in  FIG. 9  and includes a drive roller  310 , a idler roller  312  and a raised abutment surface  314 . Owing partially to the configuration of the sealing portion  120  of the fastseam  100 , shown in  FIG. 2 , the seam closing apparatus  300  is capable of completely closing the fastseam  100  along its entire length without necessitating a hammering step or the like. 
     FIG. 10  illustrates the seam closing apparatus  300  as it is first applied to the fastseam  100  of a length of duct  216 . As shown in  FIG. 10 , the seam closing apparatus  300  is applied to the fastseam  100  in a vertical orientation, bringing the drive roller  312  into contact with the sealing portion  120  of the fastseam  100 . As will be discussed in more detail later, the idler roller  312  includes a groove formed thereon to accommodate the bottom edge of the fastseam  100 . 
   Once engaged with the fastseam  100 , pressure is applied to the fastseam  100  by rotating the seam closing apparatus  300  in the general direction of the arrow X, as shown in  FIG. 11 . Actuation of the trigger  306  then causes drive roller  310  to rotate, thus flattening the partially angled sealing portion  120  captured between the drive roller  310  and the idler roller  312 . 
   The drive roller  310  will rotate in the clockwise direction (as seen in  FIGS. 10 and 11 ), propelling the seam closing tool  300  in the direction of arrow Z while flattening the sealing portion  120  to its completely sealed position. It will be readily appreciated that fastseams of varying dimensions may be accommodated via an appropriate rotation of the housing  302 . 
   It is therefore an important aspect of the present invention that the seam closing tool  300  also utilizes only a single, driven roller  310  to bend or form the sealing portion  120  to its completely sealed position. Moreover, by employing only a single driven roller  310  (which is not preceded by a plurality of additional, incremental rollers) the seam closing apparatus  300  of the present invention will permit the driven roller  310  to transverse and seal the entirety of the fastseam  100  without requiring the additional time, expense and audible discomfort of a hammering operation. 
     FIG. 12  illustrates a partial cross-section end view of the seam closing apparatus  300  as it is engaged with the fastseam  100 . As shown in  FIG. 12 , the idler roller  312  includes an annular groove  318  which serves to receive the lower bend  220  (also shown in  FIG. 2 ) of the fastseam  100 , thereby ensuring a secure lock upon, and tracking of, the fastseam  100  as the seam closing apparatus  300  is driven down the length of the fastseam  100 . 
   It should also be noted that the driven roller  310  includes an angled profile  322  such that, as shown in the cross-sectional view of  FIG. 12 , the circumference of the driven roller  310  is smaller in the area adjacent the seam closing apparatus  300  than it is at the exterior side  324  of the driven roller  310 . In this manner, the eccentrically formed driven roller  310  ensures a tight seal of the sealing portion  120  against the duct wall  216 . 
     FIG. 13  illustrates the a cross-sectional view of the operation end  308 , including internal gearing comprised of bevel and spur gears for increased power transmission and quiet operation, contained therein. In accordance with another embodiment of the present invention, and as shown in  FIG. 13 , the internal gearing of the seam closing apparatus  300  may be arranged such that the idler roller  312  may also be driven by the (unillustrated) motor contained within the housing  302 . That is, with particular respect to  FIGS. 9–12 , the idler roller  312  may itself be driven along with the drive roller  310 , thus reducing fatigue and increasing closing and travel speed down the length of the fastseam  100 . 
   As will be appreciated by consideration of the embodiments illustrated in  FIGS. 3–13 , the present invention provides a seam closing apparatus for ducts having a heretofore unknown ease of use and flexibility. Moreover, as is best seen in  FIGS. 5 and 12 , the present invention rotatably mounts the drive roller and the idler roller upon differing planar surfaces of the operation end of the seam closing apparatus. As each of these planar surfaces are discontinuous from one another, they provide the appropriate orientation, in a step-like fashion, to accommodate and align the outwardly extending sealing portion and the lower fold of the fastseam. 
   The seam closing apparatus of the present invention also advantageously promotes a quicker initial assembly of the ductwork without requiring labor intensive and oftentimes painfully loud hammering operations. Another inherent benefit of the present invention resides in the ability of the seam closing apparatus to transverse the entire length of a given duct seam. These benefits, coupled with the inherent benefits of the fastseam illustrated herein, provide a level of comfort and ease of assembly not previously realized with prior art seam closing systems. 
   While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all equivalent embodiments.