Sheet Metal Patents (Class 285/183)
  • Patent number: 11858069
    Abstract: The invention relates to an elongate profile extending in a longitudinal direction and having a first end and a second end, wherein between the first end and the second end the profile has at least one cutting line forming a cutting pattern for at least one profile section to be removed from the profile, wherein after removal of the at least one profile section from the profile the first end of the profile is bendable towards the second end of the profile and/or vice versa.
    Type: Grant
    Filed: October 30, 2018
    Date of Patent: January 2, 2024
    Assignee: CUTWORK B.V.
    Inventor: Antonin Yuji Maeno
  • Patent number: 11592041
    Abstract: A fairing, in the form of a contoured restriction, submerged on a fluid channel surface of a fluid channel through which liquid flows, re-distributes velocity fields and flow geometries upstream and in some embodiments downstream of a discontinuity, thereby preventing flow separation, reducing cavitation potential and increasing flow capacity. Such discontinuities include, but are not limited to: joints, for example elbow joints, T-joints and Y-joints; valve-trims; entrance regions to centrifugal pumps; and entrance regions to rotary valves, steps, reductions, expansions and ledges. The fairing may be fitted into the channel or integrally fabricated with the channel.
    Type: Grant
    Filed: October 28, 2020
    Date of Patent: February 28, 2023
    Assignee: Artisan Industries, Inc.
    Inventors: Peter J. Tavilla, David Hudson, Thomas Gibbons, Ute Meissner
  • Patent number: 11286951
    Abstract: A diffuser pipe is disclosed having a tubular body including a first portion extending in a generally radial direction, a second portion extending in a generally axial direction and terminating at a pipe outlet, and a bend portion fluidly linking the first portion and the second portion. The pipe outlet is scalloped.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: March 29, 2022
    Assignee: PRATT & WHITNEY CANADA CORP.
    Inventor: Hien Duong
  • Patent number: 10428994
    Abstract: An auto-fill two-layer two-half wear resistant elbow of a concrete pump truck consists of an outer-layer protection elbow, an inner-layer heterogeneous wear resistant combined elbow and a wear resistant connecting flange. A filling space is provided between the outer-layer protection elbow and the inner-layer heterogeneous wear resistant combined elbow. The wear resistant elbow is designed as a two-layer two-half unique structure including a protection layer and a wear resistant layer. Upon using the wear resistant elbow for the first time, the concrete grout fills the reserved slit via the heterogenous combined elbow and enters the reserved filling space, allowing the outer-layer protection elbow and the inner-layer heterogeneous wear resistant combined elbow to be fixed as a whole.
    Type: Grant
    Filed: January 28, 2016
    Date of Patent: October 1, 2019
    Inventor: Zhaohui Zhou
  • Patent number: 10132524
    Abstract: An apparatus and system and method for mixing airflow and draining condensate in a duct exposed to sub-freezing air are disclosed. An example mixing duct apparatus includes a recirculation duct and a pack duct having a first end and a second end. The first end of the pack duct is coupled to a side of the recirculation duct. The pack duct has a lip that extends into an airflow passage defined by the recirculation duct. This lip defines a flow channel for condensate in the recirculation duct to flow beneath sub-freezing air entering the recirculation duct from the pack duct to decrease ice build-up in the pack duct.
    Type: Grant
    Filed: June 23, 2015
    Date of Patent: November 20, 2018
    Assignee: The Boeing Company
    Inventors: Scott P. Ellsworth, Sonny K. Nguyen, David W. Olson
  • Patent number: 8517058
    Abstract: Segmented ductwork fittings shaped to minimize waste and labor while retaining the performance characteristics of traditional radius fittings. Lean Duct fittings utilize both curved sections and straight tubular sections at an angle to one another to provide a predetermined change in the direction or location of fluid flow through the finished duct system.
    Type: Grant
    Filed: November 1, 2011
    Date of Patent: August 27, 2013
    Inventor: Leslie Edward Santeler
  • Patent number: 8336923
    Abstract: A dryer duct elbow for attachment between a dryer vent and flexible ducting, or between flexible ducting and a wall vent, may include a first larger end, containing threading and a groove containing an O-ring, and a second tapered end, having circumferential threading and a groove containing an O-ring. Either end is capable of rotational sealing engagement with the flexible ducting, or with frictional engagement with the dryer or wall vents. The dryer duct elbow is formed of two halves which are connected together at the edges to form one elbow.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: December 25, 2012
    Assignee: Imperial Sheet Metal, Ltd.
    Inventor: Mathieu Vautour
  • Patent number: 8251406
    Abstract: A discharge elbow provided with guide vanes includes an elbow of rectangular cross section and magnification f of 1<f?5, one or more guide vanes disposed in the elbow, wherein the guide vane or the guide vanes are made of a curved plate and a pair of flat plates connected to the curved plate. One of the flat plates is located in front of the curved plate and the other is located to the rear of the curved plate. M-number of sub-channels similar to one another are formed in the elbow based on particular formulas, wherein the inner sidewall of the elbow is deformed into a curved plate coaxial with the curved plate of the adjacent guide vane to deform n=1 sub-channel into a coaxial bend channel provided with a uniform breadth equal to the inlet breadth b1 of the sub-channel.
    Type: Grant
    Filed: May 7, 2010
    Date of Patent: August 28, 2012
    Assignee: Kawano Giken Co., Ltd.
    Inventor: Michihiko Kawano
  • Patent number: 8056932
    Abstract: The invention relates to a corner accessory for placing at the junction between at least two ducts that extend in different directions, the accessory comprising two distinct flaps, one of which includes a projecting element and the other of which includes a circular opening receiving said projecting element to allow said flaps to pivot about a pivot axis, the circular edge of said opening opening out locally to a straight slot that extends radially relative to the circular edge of said opening and that opens out into a free edge of said flap. According to the invention, said projecting element is a cylindrical wall presenting firstly an outside diameter equal, ignoring clearance, to the inside diameter of said circular opening so that during pivoting of one flap relative to the other, the outside face of said cylindrical wall slides over the edge face of the circular edge of said opening, and presenting secondly a height that varies around its circumference.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: November 15, 2011
    Assignee: Legrand France
    Inventor: Thierry Wents
  • Patent number: 7393021
    Abstract: A duct system generally comprises a flexible duct; a fitting having an end including either an in-turned circumferential lip or a plurality of circumferentially arranged tabs; a collar having a first end and a second end, the first end being adapted to be secured to the flexible duct, and the second end being adapted to be secured to the end of the fitting, such that, if the second end of the fitting includes an in-turned circumferential lip, the second end of the collar includes a plurality of circumferentially arranged tabs adapted to engage the in-turned circumferential lip, and if the end of the fitting includes a plurality of circumferentially arranged tabs, the second end of the collar includes an in-turned circumferential lip adapted to engage the plurality of circumferentially arranged tabs; and at least one gasket for forming a seal between the fitting and the collar.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: July 1, 2008
    Inventor: Serge Lukjan
  • Patent number: 7360799
    Abstract: A half elbow used with a second similar half elbow clads insulation or other structures about a bend. Each half elbow is formed of separate segments of thin sheet material fastened together. Each segment includes first and second edges adapted to be fastened to corresponding second and first edges of adjacent segments. The segments are fastened together and shaped so that they form a curving contour between outside edges and inside edges of the segments. The outside edges of the segments together form an outside seam and the inside edges of the segments together form an inside seam. Two outside seams of two half elbows can be joined together along with two inside seams of the two half elbows to entirely surround and cover a bend.
    Type: Grant
    Filed: August 17, 2004
    Date of Patent: April 22, 2008
    Inventor: Todd C. Price
  • Patent number: 7210505
    Abstract: An elbow for a dryer exhaust vent conduit. The elbow can have two nestable channel sections, each channel section having a generally C-shaped cross-section, which may be substantially semi-circular. Each channel section has a connection mechanism along at least one side such that the two channel sections are joinable to form a substantially tubular conduit which has a smooth interior surface, reducing friction losses to the airflow speed of the dryer exhaust. Each channel section can be curved in a large radius arc to provide a turn to the elbow, which may extend around a quarter circle to provide a 90° turn to the dryer exhaust vent conduit. Snap fit locking tabs may lock the two channel sections together. Ends of the elbow may fit into or outside adjoining conduit pipes. The channel sections can be nested for ease of transport and storage and can be easily assembled on site.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: May 1, 2007
    Inventor: Richard J. Harpenau
  • Patent number: 6588802
    Abstract: A two-part clamp-connected chimney flue tee. The tee includes an elongated main section which is detachably connected to a transversely extending bull, or snout section. The main section has flue pipe connection ends and an oval cut-out portion in its sidewall, generally midway between the connection ends. The periphery of the cut-out includes an outwardly flaring flange, for mating with a corresponding contoured end of the bull section. Hooks are mounted on the inner sidewall of the main section, on opposing sides of the cut-out. Lever-actuated clamps, having a U-shaped locking member, are mounted on opposing inner portions of the sidewalls of the contoured end of the bull section. In mating the two sections, the bull section is press-fitted over the flange surrounding the cut-out. A locking member on one side of the contoured end is engaged with a respective hook. Then, the lever on the clamp is snapped toward the adjacent sidewall, into a locked position.
    Type: Grant
    Filed: June 22, 2001
    Date of Patent: July 8, 2003
    Inventor: Fred G. Schukal
  • Patent number: 6474697
    Abstract: An exhaust elbow (1) is provided with a single exhaust outlet (2) with an outlet mounting flange (3) and at least two exhaust inlets (4, 5, 6) with an inlet mounting flange (7) for fastening on the engine block of a motor vehicle. The exhaust guiding of the exhaust elbow (1) between the inlet mounting flange (7) and the outlet mounting flange (3) is formed by a single-walled sheet metal hood (8) forming a collection line. The sheet metal hood (8) surrounds all exhaust inlets (4, 5, 6) together, without individual pipes being formed. Such a simple sheet metal elbow can be manufactured at a low cost and with low weight and nevertheless has sufficient ability to function, is dimensionally stable and can be used in a versatile manner.
    Type: Grant
    Filed: July 13, 2001
    Date of Patent: November 5, 2002
    Assignee: J. Eberspächer GmbH & Co. KG
    Inventors: Thomas Nording, Thomas Hauber, Tassilo Adam, Uwe Gräss
  • Patent number: 6471251
    Abstract: A spirally corrugated pipe elbow according to the present invention is constructed in such a manner that after a bend forming portion of a pipe body P having a given length and including a spirally corrugated pipe wall 1, with a partial portion a of the pipe wall 1 existing in the peripheral direction of the pipe body P left uncut, is cut and removed from the pipe body P in the form of a cut portion having a substantially V-like shape when it is viewed from the side surface side thereof, the thus obtained two cut surfaces are then bent and contacted with each other with the uncut pipe wall portion a set on the large diameter side, and the thus contacted portions t are connected together in a watertight manner using connecting material m. Accordingly, it is possible to provide an elbow having a structure free from the above water leakage and a method capable of manufacturing such elbow easily and quickly.
    Type: Grant
    Filed: September 27, 2000
    Date of Patent: October 29, 2002
    Assignee: Totaku Industries, Inc.
    Inventors: Tatsushi Yoshida, Kimihiro Egoshi
  • Patent number: 6431611
    Abstract: An air duct fitting comprising a rectangular cross section duct segment having a central axis, a round cross section duct segment having a central axis, and a transition rectangle-to-round segment, the rectangular cross section duct segment having a lateral round opening with a central axis transverse to the rectangular duct segment central axis, the round cross section duct segment central axis being laterally offset from and parallel to the rectangular duct segment central axis. The transition segment is removably interfitted with the rectangular cross section duct segment, whereby the rectangular cross section duct segment round opening can be oriented in either of two opposite directions, one in a plane in general alignment with the round cross section duct segment central axis and the other in a plane laterally offset from the round cross section duct segment central axis.
    Type: Grant
    Filed: June 3, 1999
    Date of Patent: August 13, 2002
    Assignee: Builder's Best, Inc.
    Inventor: John L. Andersen
  • Patent number: 6230418
    Abstract: System for installation of a complete, safe, compact, and efficient dryer exhaust. Provides access to internal areas of conduit for dryer lint build-up removal. Allows dryer placement in tight confines: laundry closets, pantry areas, first floor apartments. System may be used to route dryer exhaust conduit inside of dwelling walls.
    Type: Grant
    Filed: April 26, 2000
    Date of Patent: May 15, 2001
    Inventor: Dennis R. Gomulinski
  • Patent number: 6185837
    Abstract: A vent system has a rotatable connection between flexible conduits, which carry heated air from the dryer to an external location, such as the atmosphere. The vent system consists of a swivel coupler rotatably connecting a pair of flexible exhaust conduits, one of which is readily attachable to a dryer exhaust outlet, which discharges exhaust air from the dryer, and the other of which is readily attachable to an outlet pipe, which carries exhaust air from the flexible exhaust conduit through a wall and to the atmosphere. Each flexible exhaust conduit, which is laterally flexible and axially extensible, includes a segmented elbow allowing bending up to approximately a right angle in one direction. The swivel coupler includes a rotatable joint wherein an annular extension on one half of the connector travels in an annular indentation in the other half so as to enable rotation therebetween.
    Type: Grant
    Filed: April 1, 1999
    Date of Patent: February 13, 2001
    Assignee: Builder's Best, Inc.
    Inventor: W. Gregory Tuggle
  • Patent number: 5957506
    Abstract: A sheet-metal elbow is coupled by direct attachment to a flat sheet-metal air inlet panel of an air distribution boot or register box by roll-formed flange portions that are mated in interlocking, overlapping engagement with each other. The air inlet panel includes an outwardly flared coupling flange bordering an air inlet opening. The neck of the sheet-metal elbow includes a folded coupling flange that is dimensioned for interfitting, overlapping engagement with the outwardly flared elbow coupling flange. The coupling flanges are clasped together by a hydraulic ram that drives an expandable mandrel into a V-shaped die cavity. The tightly clasped, overlapping flange portions permit smooth, continuous rotation of the elbow through 360.degree. with respect to the register box for alignment with a branch conduit. The interlocked flanges also provide a strong mechanical union that is virtually leak-free under normal ventilation air flow conditions.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: September 28, 1999
    Assignee: M & M Manufacturing Co., Inc.
    Inventor: Michael D. Stepp
  • Patent number: 5941231
    Abstract: A gas combustion apparatus including a housing having a top wall and a side wall, the top wall and the side wall defining vertical and horizontal openings, respectively, and the housing defining a combustion chamber having an exhaust opening; a burner mounted in the combustion chamber; and a vent assembly for venting exhaust gases generated by the burner to either the vertical or the horizontal opening, the vent assembly including two substantially identical vent conduits, each of the vent conduits having a central axis, a first end defined by a first continuous edge lying in a plane perpendicular to the central axis, and a second end defined by a second continuous edge lying in a plane at a forty-five degree angle to the central axis, the second ends of the vent conduits being connected together with the central axes of the conduits aligned to conduct exhaust gases between the exhaust opening and one of the vertical opening and the horizontal opening, and the second ends of the conduits being connected toget
    Type: Grant
    Filed: October 7, 1997
    Date of Patent: August 24, 1999
    Assignee: AOS Holding Company
    Inventors: Michael K. Garrett, Mark R. Bolduc
  • Patent number: 5405174
    Abstract: A kit for producing a non-straight connector for fluid pipe element comprises loose sleeve couplings and at least one flat blank which has been given such a shape and such dimensions that, after forming thereof and interconnecting its opposite ends, it is connectable with the sleeve couplings by means of a peripheral joint, thereby forming an intermediate segment.
    Type: Grant
    Filed: April 9, 1993
    Date of Patent: April 11, 1995
    Assignee: Lindab AB
    Inventors: Carl-Gustaf Sonden, Kenneth Lennartsson
  • Patent number: 5375891
    Abstract: An adaptor for connecting industry standard eavestrough downspouts to drainage extensions of a similar or dissimilar cross section and allowing the extension to be pivoted vertically. Such an adaptor is shown with portions having two different cross sections, one capable of fitting outside several industry standard drainage extensions and having a hinge between the two portions. A mating Velcro.TM. loop-and-hook pair is installed on the drainage extension's outer end and at an appropriate place up the downspout. Thus, a downspout with a round, or squared, or rectangular cross section can be connected to an extension with any of these cross sections, making a total of nine permutations and more if minor bending or fitting of further sizes and shapes of downspouts or extensions is undertaken. In the preferred embodiment, the extension can thereafter be raised to a vertical position and separably fastened there.
    Type: Grant
    Filed: December 14, 1992
    Date of Patent: December 27, 1994
    Assignee: Metro Eavestroughing Ltd.
    Inventors: Jean Sicotte, Denis Sicotte
  • Patent number: 5288111
    Abstract: A 90.degree. elbow for pneumatic transport pipes includes a tubular asymmetric cross-sectional expansion at the entrance side, a baffle plate along the outer elbow side and a tubular asymmetric cross-sectional contraction at the exit side of the elbow. The baffle plate is arranged at an angle between about 55.degree. and 65.degree. relative to the incoming flow direction of bulk material. The inner elbow side is defined by a quadrantal pipe shell, with the remaining area being complemented by segments to provide a closed cross section.
    Type: Grant
    Filed: April 6, 1992
    Date of Patent: February 22, 1994
    Assignee: Waeschle Maschinenfabrik GmbH
    Inventors: Robert Storf, Klaus-Peter Lang
  • Patent number: 5199190
    Abstract: A venting assembly preferably for a clothes dryer to provide a universal dryer venting assembly directed to a dryer vent and flexible vent tube assembly, has an elbow with swivel fittings at the inlet and outlet. The inlet and outlet connections include snap or collar connections for attachment to the appliance or vent tubing assembly.
    Type: Grant
    Filed: November 19, 1990
    Date of Patent: April 6, 1993
    Assignee: Champion Furnace Pipe Company
    Inventors: James J. Mayer, James L. Ratton
  • Patent number: 5145217
    Abstract: A dryer duct assembly employs two universal elbow components and at least one flexible component. The flexible component has ends capable of connecting to another flexible component or to a universal component without the use of other devices such as hose clamps to secure connection. Each elbow has ends capable of attaching either to the wall opening or the dryer, in addition to attaching to the flexible component in the same manner as the flexible components may attach to each other. The elbow has an outer portion resembling the outer portion of a quarter-toroid, and a square type inner portion. The outer portion is made of a pair of mirror image hemi portions connected at adjacent flanges. The inner portion has an L-shaped plate with flow-through orifices in each leg of the L.
    Type: Grant
    Filed: December 4, 1990
    Date of Patent: September 8, 1992
    Assignee: Builder's Pride, Inc.
    Inventors: Charles B. Anderson, Charles R. Kenrick
  • Patent number: 5121948
    Abstract: Disclosed is a metal dryer exhaust duct assembly using a pair of flexible corrugated metal ducts capable of linear extension and capable of reorientation of the duct ends, a pair of elbow connectors, one for attachment to a dryer exhaust outlet and the other for attachment to a wall inlet. Each duct has a swivel connection to its respective elbow connector, using a sleeve which interfits with the elbow connector by a peripheral projection and recess arrangement. Each duct can also be interfit with another such duct. The two ducts can be attached respectively to an dryer and a wall spaced from each other, and are vertically self supporting, whereby when the dryer is moved adjacent the wall, a person can readily telescopically interconnect the ends of the ducts over the top of the dryer. One or more pieces of the duct may be used to span the distance between the dryer and the wall outlet.
    Type: Grant
    Filed: December 4, 1990
    Date of Patent: June 16, 1992
    Assignee: Builder's Pride, Inc.
    Inventors: Charles B. Anderson, Charles R. Kenrick
  • Patent number: 4694547
    Abstract: An improved one-piece metal jacket for insulated pipe elbows, bends and/or turns having a central metal spine spaced apart along which a plurality of opposed pairs of metal fingers extend sufficiently to overlap, longitudinally and traversely forming a weatherproof covering and fasteners to hold the fingers in place.
    Type: Grant
    Filed: February 6, 1986
    Date of Patent: September 22, 1987
    Inventor: Edison L. Broussard
  • Patent number: 4440337
    Abstract: A method of producing similar deep-drawn parts for double-walled structural parts having uniformly spaced walls and edge welding. During every deep-drawing procedure, a respective planar outer plate, which is placed upon the lower part of the tool, as is a filler plate, as well as a preformed or preshaped inner plate, which is placed over the tool punch, are shaped in common, whereby the preformed inner plate and the outer plate receive their final form or shape, and the filler plate is deformed into a preshaped inner plate for a subsequent deep-drawing procedure. The tool for carrying out this method is characterized in that the smallest spacing between the tool punch and the lower part of the tool corresponds to the entire thickness of the two inner plates and one outer plate.
    Type: Grant
    Filed: October 8, 1981
    Date of Patent: April 3, 1984
    Assignee: Klockner-Humboldt-Deutz Aktiengesellschaft
    Inventor: Rolf Eckert
  • Patent number: 4294474
    Abstract: A prefabricated chimney-shaft constructed from an outer sheath surrounding an inner sheath, in which the end portions of the inner and the outer sheaths are interconnected by perpendicularly positioned tie members having bent-over rims joining the sheaths, such that at one end the rims project a longitudinal distance out of the outer sheath, and at the other end the tie member and rims are recessed a longitudinal distance from the end of the outer sheath.
    Type: Grant
    Filed: September 25, 1978
    Date of Patent: October 13, 1981
    Inventor: Josephus J. D. Harm
  • Patent number: 4288111
    Abstract: A first section of cylindrical sheet metal duct has a end roll-formed to define an outwardly formed flange, a central cylindrical flange whose axis is parallel to the cylindrical wall of the duct and which is radially outwardly offset from the cylindrical wall, and an inwardly formed end flange. This configuration defines a male section and the end of a mating section of cylindrical duct is formed to define a female section having an outwardly formed flange extending from the cylindrical wall and a cylindrical end flange whose axis is parallel to the cylindrical wall and radially outwardly offset from the cylindrical wall with a diameter slightly greater than the diameter of the corresponding cylindrically offset flange of the male section such that the male section can extend into and be seatably received by the female section.
    Type: Grant
    Filed: January 21, 1980
    Date of Patent: September 8, 1981
    Assignee: Enterprise Construction Services, Inc.
    Inventor: Roger A. Feutz
  • Patent number: 4193759
    Abstract: A rotary kiln has at one end circumferentially spaced apart outlet openings into each of which extends a sleeve establishing communication between the interior of the kiln and a planetary cooling tube. Encircling the inner end of each sleeve is a refractory collar that is flush with the surface of the kiln's lining. Between each tube and the edge of the associated outlet is a thermally insulative packing.
    Type: Grant
    Filed: January 3, 1978
    Date of Patent: March 18, 1980
    Assignee: Polysius AG
    Inventors: Jurgen Wurr, Antonius Vering, Bodo Ermer
  • Patent number: 4054985
    Abstract: A protective cover for an insulated pipe bend. A corrugated band-form material is spirally wound into a tube and the adjoining tube edges are secured, such as by lapping, to form a non-slipping joint. The corrugated tube thus provided can be readily shaped to conform to an existing tube bend. The corrugated tube is cut lengthwise into two or more parts which are then placed over the insulated pipe bend. The cut edges are re-joined to form the protective cover.
    Type: Grant
    Filed: June 3, 1976
    Date of Patent: October 25, 1977
    Assignee: Isolerings Aktiebolaget Isenta
    Inventor: Sven Goran Aleniusson
  • Patent number: 4009894
    Abstract: Disclosed is a fitting having an attachment configuration for end-to-panel securing of the fitting to an insulated duct. The fitting is provided with a standing flange spaced from the end margin of the fitting a distance substantially equal to the thickness of the insulated duct wall adjacent the opening therein and limiting the depth of insertion of the fitting into the opening. An outwardly extending tab or flange is located on one portion of the end margin of the fitting and is adapted to back the adjacent duct wall. A separate member, L-shaped in cross-section, is attached to an opposite portion of the end wall margin after insertion of the fitting, one leg of the L-shaped member backing the adjacent duct wall.
    Type: Grant
    Filed: January 16, 1976
    Date of Patent: March 1, 1977
    Assignee: Mutz Corporation
    Inventors: Ralph L. Marquette, James E. Jones
  • Patent number: 3988030
    Abstract: This invention relates to a slip-joint coupling between a sheet metal duct fitting and the metal frame bordering a rectangular opening in a so-called "duct board" consisting of a fiberglass mat overlayed with a sheet of silvered paper backing adhesively attached to one face of the latter, such coupling comprising outturned flanges along both side margins and the leading edge of the fitting plus an inturned flange on the trailing edge of the latter, all of which cooperate with a three-sided frame having outwardly opening channels on each side and across one end to receive the duct board together with relatively narrower inwardly opening channels on one face for slidably receiving the outturned flanges of the fitting. With the fitting and frame in assembled relation, the inturned flange is bent down to complete the fourth side of the frame, lock the assembly within the duct opening and complete the air seal along the fourth side of the latter.
    Type: Grant
    Filed: May 12, 1975
    Date of Patent: October 26, 1976
    Inventor: Jack L. Twedell