Abstract: A seam for ductwork has a male end portion integrally formed at a distal end of a duct wall and a female end portion integrally formed at another distal end of the duct wall. The female end portion includes a first fold and a second fold, which define a female groove for accommodating the male portion. A distal end of the second fold is bent transverse to the female groove prior to the male portion being inserted into the female groove.

Abstract: An exhaust system for a plasma cutting machine which uses an outside air supply to provide needed airflow to a cutting table thereof is disclosed. Airflow into the cutting table may be controlled and directed to select zones of the cutting table.

Abstract: A duct reinforcing rod and fabrication apparatus for use with a conduit and a threaded element dimensioned to fit within the conduit includes a positioning device to position the conduit at an insertion position and an insertion device for inserting the threaded element a predetermined distance into the conduit. A deformation device is also employed to deform the conduit such that the deformation occurs at two locations on the conduit, the two locations being longitudinally spaced from one another along a length of the conduit.

Abstract: A seam for ductwork has a male end portion integrally formed at a distal end of a duct wall and a female end portion integrally formed at another distal end of the duct wall. The female end portion includes a first fold and a second fold, which define a female groove for accommodating the male portion. A distal end of the second fold is bent transverse to the female groove prior to the male portion being inserted into the female groove.

Abstract: A seam for ductwork has a male end portion integrally formed at a distal end of a duct wall and a female end portion integrally formed at another distal end of the duct wall. The female end portion includes a first fold and a second fold which define a female groove for accommodating the male portion. A distal end of the second fold is bent transverse to the female groove prior to the male portion being inserted into the female groove.

Abstract: An integral transverse flange for a duct includes a first upturned portion extending substantially perpendicularly from a duct wall of the duct. The flange further includes a second portion bent rearwardly from the first upturned portion, and a third return portion turned toward the duct wall and rounded back toward the first upturned portion from the second portion. A fourth L-shaped portion extends from the third return portion, the L-shaped portion having a first arm arranged adjacent to and in close relation with the second portion and a second arm arranged adjacent to and in close relation with the first upturned portion. A bead is formed in the first upturned portion.

Abstract: A seam closing apparatus for use in sealing a duct seam having an outwardly extending sealing portion and a lower fold includes a handle portion having a power actuation trigger and a first roller for engaging the outwardly extending sealing portion of the duct seam. A second roller is also provided for engaging the lower fold of the duct seam. Operation of the power actuation trigger causes the first roller to rotate in a first direction, thereby flattening the outwardly extending sealing portion of the duct seam.

Abstract: A roller assembly for processing a substantially planar workpiece includes a first pinch rod and a second pinch rod mounted in opposition to the first pinch rod, the workpiece passing between the first pinch rod and the second pinch rod during operation. A radius rod is also mounted adjacent to the first pinch rod and the second pinch rod, the radius rod being selectively displaceable with respect to the first and second pinch rods to contact the workpiece after the workpiece has passed between the first and second pinch rods, the radius rod conferring a predetermined radius of curvature to the workpiece. The roller assembly further includes a roller mounted onto one of said first pinch rod, the second pinch rod or the radius rod, the roller being selectively positionable along one of the first pinch rod, the second pinch rod and the radius rod.

Abstract: A seam for ductwork has a male end portion integrally formed at a distal end of a duct wall and a female end portion integrally formed at another distal end of the duct wall. The female end portion includes a first fold and a second fold which define a female groove for accommodating the male portion. A distal end of the second fold is bent transverse to the female groove prior to the male portion being inserted into the female groove.

Abstract: A seam closing apparatus for use in sealing a duct seam having an outwardly extending sealing portion and a lower fold includes a handle portion having a power actuation trigger and a first roller for engaging the outwardly extending sealing portion of the duct seam. A second roller is also provided for engaging the lower fold of the duct seam. Operation of the power actuation trigger causes the first roller to rotate in a first direction, thereby flattening the outwardly extending sealing portion of the duct seam.

Abstract: A cornerless slip-on flange system for duct connections. The system utilizes flange pieces to form a frame at the end of a duct section without the use of connectors at the corners of the flanges, the frames of two sections being used to join the two ducts sections together. The flange pieces each have a male end and a female end with the male end of one flange piece being inserted into the female end of the adjacent flange piece at each corner to form the frame. The frames can then be installed on the ends of the ducts to be joined and fastened together by inserting suitable fasteners through preformed openings in the flange pieces.

Abstract: Flat metal strip of indeterminate length is apertured in a punch press having a flying die set to define a lengthwise succession of identical workpiece blanks connected by strap-like portions of the strip adjacent to its longitudinal edges. That press, each time it operates, makes two apertures that define respective end edges of a blank. The strip is pulled lengthwise through that press by roller forming apparatus which imparts a predetermined transverse profile to it and propels it through a flying shear press whereby each blank is severed from the rest of the strip. On a conveyor having two stretches bridged by the severed blank and moving faster than the strip the severed blank is carried to a folding press. There a ram rises from between the conveyor stretches, lifting the blank off of the conveyor and clamping it against a folding die.

Abstract: Disclosed is a roller forming machine for converting a flat metal strip into a louver having long, narrow fins that extend lengthwise of the strip and are all bent laterally in one direction oblique to the plane of the strip. The fins are produced by a pair of fin forming rollers which slit the strip and bend out the fins to a larger acute angle to the plane of the strip than is desired in the finished louver. The strip then tends to twist along its length due to asymmetrical residual stresses generated by fin formation. To remove the twist, the strip is passed between cylindrical straightening rollers whereby the fins are bent partway back towards coplanarity with the strip, thus generating new residual stresses which oppose the original ones due to fin forming. One straightening roller is adjustable towards and from the other so that said new residual stresses can be empirically brought into equilibrium with the original ones.