Abstract
A fastening member for joining together adjacent duct sections includes a head and a shank extending from the head, the shank having an unthreaded space adjacent to the head and a threaded portion extending from the unthreaded space, the threaded portion threadedly engaging a hole of an inserted corner plate positioned in flange of a first duct section. When the fastening member is fully inserted, the inserted corner plate positioned in the flange of the first duct section is retained within the unthreaded space.
Claims
1. A system of fastening first and second duct sections, comprising: first and second inserted corner plates positioned at respective ends of the first and second duct sections, the inserted corner plates having holes extending therethrough between opposite surfaces thereof, respectively, positioned to be aligned when the first and second duct sections are positioned for assembly; and a screw having a head and a shank extending therefrom having an unthreaded space adjacent to the head and a threaded portion extending from the unthreaded space to a tip of the shank, the threaded portion being configured to threadedly engage the holes of the inserted corner plates, respectively; wherein the unthreaded space of the screw has a length between an endmost thread of the threaded portion and the head about equal to a thickness between the opposite surfaces of the inserted corner plate of the first duct section such that the space will be located in the hole thereof when the screw is fully received therein; wherein the holes in the inserted corner plates are shaped so as to threadably receive the threads of the screw without cutting threads; and wherein the holes in the inserted corner plates are devoid of threads.
2. The system of claim 1 wherein: the holes in the inserted corner plates are at least one of a teardrop shape, a diamond shape with contoured corners at two opposing corners of the opening, an eye shape, a rectangular shape, or a half-diamond shape on one end and a curved shape on an opposite end.
3. A system of joining first and second duct sections, comprising: first and second inserted corner plates positioned at respective ends of the first and second duct sections, the inserted corner plates having holes extending therethrough between opposite surfaces thereof, respectively, positioned to be aligned when the first and second duct sections are positioned for assembly; and a screw having a head and a shank extending therefrom having an unthreaded space adjacent to the head and a threaded portion extending from the unthreaded space to a tip of the shank, the threaded portion being configured to threadedly engage the holes of the inserted corner plates, respectively; wherein the unthreaded space of the screw has a length between an endmost thread of the threaded portion and the head about equal to a thickness between the opposite surfaces of the inserted corner plate of the first duct section such that the space will be located in the hole thereof when the screw is fully received therein; wherein the endmost thread is configured to bear against one of the opposite surfaces when the screw is fully received in the hole of the corner plate of the first duct section, to hold the screw in a substantially perpendicular orientation to at least one of the opposite surfaces thereof and prevent threaded re-engagement of the screw with the hole therethrough while allowing rotation of the screw; wherein the holes in the inserted corner plates are shaped so as to threadably receive the threads of the screw without cutting threads; and wherein the holes in the inserted corner plates are devoid of threads.
4. The system of claim 3, wherein: the holes in the inserted corner plates are at least one of a teardrop shape, a diamond shape with contoured corners at two opposing corners of the opening, an eye shape, a rectangular shape, or a half-diamond shape on one end and a curved shape on an opposite end.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a cross sectional view of a prior art flanged duct connection showing a clip in an initial position for connecting mating duct section flanges.
(2) FIG. 1A is another cross sectional view of the prior art duct connection showing the clip in a partially installed position.
(3) FIG. 1B is still another cross sectional view of the prior art connection showing the clip in its fully engaged position.
(4) FIG. 2 is an end view of a prior art duct flange showing a prior art adhesive tape gasket adhered thereon.
(5) FIG. 3 is a side view of a prior art roll of gasket tape.
(6) FIG. 3A is an end view of the role of gasket tape showing non-stick tape each winding of the gasket.
(7) FIG. 4 is a perspective view of a prior art flanged duct section end having generic corner plates in place with adhesive tape gasket applied to the duct section flange and a portion of the inserted corner plate along with an overlap of the adhesive tape gasket.
(8) FIG. 5 depicts a common drift pin or tapered punch.
(9) FIG. 6 is a sectional view of a prior art pair of duct section flanges with corner plates inserted and a drift pin in close proximity.
(10) FIG. 6A is another sectional view of the prior art duct section flanges showing the drift pin partially inserted through the duct section flange and inserted corner plates.
(11) FIG. 6B is another sectional view of the prior art duct section flanges illustrating completed alignment of the flanged duct section ends with a clamp in place.
(12) FIG. 6C is another sectional view of the prior art duct section flanges showing the drift pin removed and a carriage bolt, washer and nut in place through the mated duct section flanges and inserted corner plates.
(13) FIG. 6D is another sectional view of the prior art duct section flanges shown finally assembled without the clamp.
(14) FIGS. 7A, 7C, 7E, 7G, and 7I are end views of representative duct flange corner plates usable with the invention, illustrating various optional shape holes for receiving screws of the invention.
(15) FIGS. 7, 7B, 7D, 7F, and 7H are end views, and FIG. 7J is a perspective view, of additional representative corner plates usable with the invention, illustrating another optional shape hole for receiving screws of the invention.
(16) FIG. 7K is a perspective view of a plain generic duct flange corner plate with one opening for receiving a screw of the invention.
(17) FIG. 8 is an end view of a duct section flange with a bead of semi fluid gasket caulking applied to a surface thereof.
(18) FIG. 9 is a perspective view of an end of a duct section with a bead of gasket caulk on the connection area of the duct section flange, and large sheet metal screws positioned for insertion through openings provided in each of the four inserted corner plates along with self-drilling screws shown at spaced intervals along each duct section flange.
(19) FIG. 10 is a sectional view showing two duct section flanges and a caulking bead on one flange in spaced apart relation with a large piloted sheet metal screw having an unthreaded space adjacent to a head of the screw, the flanges and screw shown in predetermined axial alignment with holes through the inserted corner plates and duct flanges.
(20) FIG. 10A is another sectional view of the two duct section flanges shown with the large screw fully received in the hole through a first of the corner plates and projecting toward the mating duct flange and corner plate.
(21) FIG. 10-1 is a sectional view of the two duct flanges with the screw tilted relative to an alignment axis through aligned inserted corner plates of the flanges and partially threadedly engaged with the hole of a first of the inserted corner plates, and showing a thread pitch of about one sheet metal thickness (thickness of corner plate) between the adjacent threads of the screw.
(22) FIG. 10-2 is an enlarged side view of an unthreaded space between the head of the screw and an endmost thread of a threaded portion of the screw, showing an extent of the endmost thread in parallel relation to an opposing surface of the head and extension of the endmost thread into a groove between the endmost thread and the next adjacent thread.
(23) FIG. 10B is a sectional view of the duct section flanges with inserted corner plate of a first of the flanges with the screw fully received in the hole therethrough, positioned in spaced apart aligned relation to the corner plate of a second of the flanges with a tip of the screw inserted into the hole therethrough.
(24) FIG. 10C is another sectional view of the duct section flanges, showing the screw partially threadedly engaged with the hole through the corner plate of the second of the flanges.
(25) FIG. 10D is another sectional view of the duct section flanges, showing the screw fully threadedly engaged with the hole through the corner plate of the second of the flanges compressing a semi-fluid gasket between the flange to flange connection, illustrating complete assembly of the flanges.
(26) FIG. 10E is a sectional view of alternative duct section flanges and associated flat style inserted corner plates, showing the screw fully received in the hole of the corner plate of a first of the flanges, and fully threadedly engaged with the hole through the corner plate of the second of the flanges compressing a semi-fluid gasket between the flanges, illustrating complete assembly of the flanges.
(27) FIG. 10F is a sectional view of assembled duct section flange with the large screw holding a hanger bracket between both flanges with a threaded support rod shown in place and connected to the hanger bracket.
(28) FIG. 10G is a perspective view of the hanger bracket showing illustrating a manner of connection to the support rod.
(29) FIG. 10H is a side view of a cable hanger bracket.
(30) FIG. 10I is an assembly drawing of the cable hanger bracket disposed between two duct section flange assemblies for clamping therebetween.
(31) FIG. 10J is an assembly drawing of an alternative cable hanger bracket disposed between two duct section flange assemblies for clamping therebetween.
(32) FIG. 10K is a side view of the alternative cable hanger bracket, a cable support and a cable clamp.
(33) FIG. 10M is a side view of the screw in aligned relation to a duct section flange and inserted corner plate.
(34) FIG. 10M-1 is a sectional view CC showing the endmost thread of a threaded portion of the screw.
(35) FIG. 10M-2 is a section DD showing the hole through the inserted corner plate and an area of locking interference of the endmost thread and an edge of the hole.
(36) FIG. 11 is a fragmentary perspective view of mating duct section end corners with inserted corner plates of two flanged duct sections, positioned for assembly and showing a single screw through the hole through one of the inserted corner plates.
(37) FIG. 11A is another fragmentary perspective view of the mating duct section end corners with inserted corner plates of two flanged duct sections, showing three screws through holes of one of the inserted corner plates.
(38) FIG. 12 is a fragmentary perspective view of two mating duct section flanges with inserted corner plates in spaced apart alignment for assembly with a caulk bead in place there between and a combination of a single screw and triple screw connection, along with Tek screws and pre-made holes at spaced locations along the flanges.
(39) FIG. 13 is a sectional view of a prior art generic slide on duct section flange connection for rectangular, round, oval or other duct sections with slide on flanges positioned on un-flanged ends of duct sections, assembled with a carriage bolt.
(40) FIG. 13A is a side view of an inserted corner plate of the connection of FIG. 13.
(41) FIG. 13B is an end view of the corner plate.
(42) FIG. 14 is an end view of a prior art slide on flange separately located with semi fluid sealant caulk gasket material in location for sealing duct sections at the ends.
(43) FIG. 15 is a sectional view of a slide on flange connection according to the invention, for sealing rectangular, round, oval or other duct sections for rectangular and other style duct ends.
(44) FIG. 15A is a side view of the slide on flange.
(45) FIG. 15B is an end view of the slide on flange.
(46) FIG. 16 is a side view of an inserted corner duct flange connection clamping a center loaded hanger bracket.
(47) FIG. 16A is a side view of an inserted corner duct flange connection clamping an alternative hanger bracket.
(48) FIG. 17 is a sectional view of an inserted corner duct flange connection clamping a hanger bracket and showing connection with a hanger rod and a space between the flanges.
(49) FIG. 17A is an enlarged sectional view of the connection through the hanger bracket, showing the flanges brought together by bending the corner plates and flanges with an added screw through the flanges alongside the hanger bracket to close the space.
(50) FIG. 17B is a side view that shows the corner plate and a section of a duct section bent at an area by an adjacent screw in order to bring the flanges into sealed contact.
(51) FIG. 18 is a side view of a spaced apart, aligned relationship of duct sections with end connection flanges having inserted corner plates with the large screw and a gasket applied to one of the duct section flanges.
(52) FIG. 19 is an enlarged sectional view showing only the top duct section flanges in spaced apart, aligned relation.
(53) FIG. 20 is a fragmentary sectional view of a duct section flange and drill tip screw, showing use of the corner plate hole as a drill guide.
(54) FIG. 20A is a fragmentary sectional view of a duct section flange and a hollow ended drill tip screw, showing use of the corner plate hole as a drill guide.
(55) FIG. 20B is a fragmentary sectional view showing a piloted screw end with a spade drill tip, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(56) FIG. 20C is a fragmentary sectional view showing a piloted screw end with a cylindrical drill tip, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(57) FIG. 21 is a fragmentary sectional view showing a cylindrical pilot tip screw, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(58) FIG. 21A is a fragmentary sectional view showing a threaded tapered pilot tip screw, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(59) FIG. 21B is a fragmentary sectional view showing a conical pilot tip screw, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(60) FIG. 22 is a fragmentary sectional view showing another conical pilot tip screw, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(61) FIG. 22A is a fragmentary sectional view showing another threaded tapered pilot tip screw, fully received in the hole of a first inserted corner plate and inserted into the hole of a second inserted corner plate.
(62) FIG. 23 is a fragmentary sectional view of a preferred embodiment screw in tilted and threaded engagement with a hole through a corner plate.
(63) FIG. 23A is an end view showing a representative prior art oval shape hole through a corner plate.
(64) FIGS. 23B, 23C, 23D, 23E, 23F, 23H, and 23I show various functional shape holes through inserted corner plates that allow threaded engagement with a screw without formed or cut threads in the plate.
(65) FIGS. 23B, 23C, 23E, 23F, 23G, 23H, and 23I show additional various functional shape holes that can act as a guide for a drill bit or self-drilling screw during the drilling process for unpunched duct section flanges.
(66) FIG. 24 is a sectional view showing a prior art fastener with thread pitch or spacing between adjacent threads about equal to the thickness of two corner plates, shown fastening together inserted corner plates of two duct sections, assembled.
(67) FIG. 24A is a side view of the prior art fastener shown in FIG. 24 in tilted initial threaded engagement with the inserted corner plates.
(68) FIG. 25 is an end view of one preferred embodiment of a corner plate.
(69) FIG. 26 is a side view of an inserted corner duct flange connection clamping an alternative cable type bracket.
(70) FIG. 26A is an end view of a serrated washer surface of a screw of the alternative cable type bracket and illustrating a manner of wrapping the cable about the screw.
(71) FIG. 27 is an end view of a duct section assembly and alternative cable hangers.
(72) FIG. 28 is an end view of a duct section assembly and an alternative cable hanging arrangement.
(73) FIG. 29 is a side view of an embodiment of a screw of the invention, showing an endmost thread of the screw.
(74) FIG. 30 is a fragmentary end view of a duct section assembly including inserted corner plates incorporating elements for connection to hanger brackets.
(75) FIG. 31 is a sectional view of the duct section assembly of FIG. 30 including inserted corner plates incorporating elements for connection to hanger brackets, and showing a hanger bracket in connection therewith.
(76) FIG. 32 is a sectional view of the duct section assembly of FIG. 30 including inserted corner plates incorporating elements for connection to hanger brackets, and showing an alternative hanger bracket in connection therewith.
(77) FIG. 33 is a top view of a sheet metal nut having a representative teardrop shape hole therein, for use the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
(78) Referring to the drawings wherein like numerals refer to like parts, FIG. 1 illustrates a typical prior art duct flange connection as currently practiced showing a clip 18, a gasket 17 and duct section end flanges 14. FIG. 1A teaches applying the clip 18 by rotating it into position over and around the flanges 14 as illustrated by the arrow. FIG. 1B shows the clip 18 in a final holding position about the flanges 14.
(79) FIG. 2 gives the information needed to place the gasket tape 17 properly on the duct section flanges 14. FIG. 3 and FIG. 3A illustrate the typical adhesive tape 17 used for duct joining and shows the non-stick paper backing 20 provided with the tape 17. As the tape 17 is unwound and applied the paper 20 must be crumpled together or otherwise disposed of.
(80) FIG. 4 shows the tape 17 applied to the end of a duct section flange 14 with a lap 39 where the end of the tape 17 starts and stops. Inserted corner plates 21 are shown in place in the duct section end flange 14. FIG. 5 shows a common drift pin 24 or tapered punch. FIG. 6 shows preparatory alignment of integral duct section flanges 14 or slide on duct section flanges 66 through the use of drift pin 24 through aligned holes through the corner plates 21. FIG. 6A shows the beginning of the insertion process of drift pin 24 into the holes through corner plates 21 of the duct section flange with gasket 17 separate and apart from the mating duct flange 14. It should be understood that if gasket 17 were to inadvertently contact and adhere to the opposing duct flange 14 while flanges 14 are misaligned, it would be difficult and time consuming to remove and correct and often requires disassembly and scraping or peeling of the gasket for removal and replacement with a new gasket and re-alignment. FIG. 6B shows drift pin 24 fully aligned and engaged with corner plates 21 with gasket 17 clamped against the mating duct section flange 14 by clamps 280.
(81) FIG. 6C illustrates after removal of drift pin 24, the insertion of carriage bolt 25 through the holes of the corner plates 21 with washer 27 and nut 26 securely fastened about and through corner plates 21. FIG. 6D shows a completed assembly of the duct section flanges and corner plates 21 with adhesive tape gasket 17 properly adhered and carriage bolt 25 tightened.
(82) FIGS. 7A, 7C, 7E, 7G, and 7I show corner plates 21 of different styles variously including holes 283 therethrough. FIGS. 7, 7B, 7D, 7F, 7H, and 7J show corner plates 28 of those same styles with the addition of holes 281 for use in the system and method of the invention. FIG. 7K shows the addition of corner plate 37 for use with slide on duct section flanges and a single hole 282.
(83) FIG. 8 is a view of a duct section flange 14 with a fluid caulk gasket applied thereto by the use of a hand caulking tube 23. FIG. 9 is a view of a flanged duct section end 34 with inserted corner plates 28 in place with caulk gasket 22 applied on the entire duct section flange 14. Screws 35 of the invention are shown in alignment with holes 281 provided in corner plates 28. Additional screws, which can include, but are not limited to, self-drilling Tek screws represented by screw 38 are shown in spaced relationship along duct section flange channel 14 in centered alignment along each side of the duct section flange end 14 for additionally fastening together duct section flange 14 with a mating duct section flange.
(84) FIGS. 10, 10A, 10-1 show duct flanges 14 of representative duct sections 33 and 34 in a spaced apart aligned state for assembly 300, according to the invention. First and second inserted corner plates 28 are representatively disposed and crimped in place in cavities of flanges 14 in the well known manner. A sealant caulking bead 22 is in place on one of the flanges 14 with a representative screw 35, having a head 29′, in coaxial alignment with an alignment axis 350 through holes 351 through inserted corner plates 28 of the flanges 14. FIG. 10A shows the screw 35 fully received in hole 351 of a first of the corner plates 28, with corner plate 28 disposed in an unthreaded space 30 between a head 29 and an endmost thread 301 of a threaded portion 32 of the screw 35 according to the invention. Duct section flanges 14 remain in spaced apart relation.
(85) FIG. 10-1 shows screw 35 tilted with a center axis 355 thereof at a representative approach angle relative to alignment axis 350 through aligned holes 351 of inserted corner plates 28, with screw 35 threadedly engaged with hole 351 of a first inserted corner plate 28. It can be observed that the pitch of threaded portion 32 between adjacent threads is about equal to the thickness of corner plate 28 as measured between opposite surfaces thereof about hole 351, which is desired and advantageous as noted as it enables the threaded engagement without requiring the forced cutting of threads in plate 28 or significant deformation thereof. A preferred angle of tilt will generally correspond to a pitch angle or lead of the threads of threaded portion 32 about the major diameter of the screw, so that the threaded portion 32 of screw 35 can threadedly engage hole 351 of the first corner plate 28 and rotatably pass therethrough with minimum resistance and applied torque, which is advantageous for conserving energy when screw 35 is driven by a battery operated device or by hand.
(86) FIG. 10-2 gives a close up of the space 30 adjacent head 29 of screw 35 showing an extension 356 of the endmost thread 301 of threaded portion 32 extending into a groove 354 between endmost thread 301 and a next adjacent thread 352 of threaded portion 32, as a representative configuration of endmost thread 301 for preventing or obstructing re-engagement of threaded portion 32 of screw 35 with hole 351 of the first corner plate 28, once the screw 35 is fully received in hole 351, as shown in FIG. 10A and subsequently in FIGS. 10B-10E. As can be observed in FIGS. 10A-10E space 30 between endmost thread 301 and the screw head 29 is of a predetermined extent about equal to the thickness of corner plate 28 as measured between opposite surfaces thereof about or adjacent to hole 351, such that when screw 35 is fully received in hole 351, the head 29 and endmost thread 301 will abut plate 28, and cooperate to hold screw 35 in a substantially perpendicular orientation relative to the corner plate, which locates axis 355 through screw 35 substantially coaxial with alignment axis 350 through hole 351 through the first corner plate 28, and also hole 351 through the second corner plate 28 when the corner plates are aligned for assembling the associated duct sections 33, 34.
(87) In the substantially perpendicular orientation shown when screw 35 is fully received in hole 351 of the first corner plate 28, endmost thread 301 is configured to bear or exert a force against the adjacent opposing surface of the corner plate, such that screw 35 will essentially self hold or lock in this position. This bearing force should be sufficiently robust to hold this orientation in opposition to forces and loads anticipated to be exerted laterally and the like, resulting from manipulations and handling of the associated duct sections as they are brought into alignment, e.g., by manual movements. As a result, the screws 35 provide a useful alignment tool.
(88) As a related note, endmost thread 301 and head 29 of screw 35 are configured to transition the screw from the tilted orientation of FIG. 10-1 to the substantially perpendicular alignment orientation of the fully received position shown in the other FIGS, e.g., by an automatic action, e.g., a pivoting movement about extension 356, as the screw reaches the fully received position wherein corner plate 35 enters space 30. At this time, threaded portion 32 threadedly disengages from hole 351, but endmost thread 301 is now in abutting contact or engagement with the opposing edge of the corner plate and bears thereagainst in the above described manner. Further in this regard, screw 35 now threadedly disengaged, can rotate in hole 351 relative to the corner plate without moving axially, and the configuration of endmost thread 301, the perpendicular orientation, and lack of a cut thread or deformation of the corner plate for threaded engagement, combine to prevent threaded re-engagement of threaded portion 32 with the corner plate when relatively rotated, including in the direction for re-engagement.
(89) FIG. 10B provides a view of screw 35 with a pilot 31 on the tip of screw 35 located in hole 351 of the second corner plate 28 with duct section flanges 14 in aligned and spaced apart relationship with each other with semi-liquid caulk gasket 22 protected from improper engagement with the mating duct section flange 14. FIG. 10C depicts screw 35 in initial engagement with the mating duct section flange 14 with one or more threads of threaded portion 32 threadedly engaged with hole 351 of the mating inserted corner plate 28 while maintaining axial alignment with hole 351. As this occurs, corner plates 28 are held in cavities 33, 34 by the crimped configuration of flanges 14.
(90) FIG. 10D shows full threaded engagement of screw 35 with the second corner plate 28, to clamp duct section flanges 14 into full engagement. As screw 35 threadedly engages hole 351 of the second corner plate 28, it will forceably cut a thread therein, or deform the adjacent portion or region of that corner plate as denoted by representative bend 82 to pass through the hole 351, which deformation is accommodated by the large adjacent clearance hole through the associated flange 14. At the same time, the semi-liquid caulk gasket is compressed between the flanges as denoted by protrusion 17A from the joint.
(91) FIG. 10E shows alternative flat inserted corner plates 41 retained on the flanges of duct sections 33, 34 by crimped flange edges 141 and screw 35 secured in holes 351 through corner plates 41, again creating a bend 82 in the second corner plate 41 as just described.
(92) FIG. 10F shows duct sections 14 incorporating a hanger bracket 42 of the invention fastened between the duct section flanges with screw 35 engaged in the above described manner with corner plates 28 retained on the flanges of duct sections 33, 34 again by crimping. Also referring to FIG. 10G, duct section support threaded rod 43—being a portion of a duct support assembly 44—is shown in position 51 for being readily engaged with lifted duct section assembly position 50 for final positioning in location 52. Nuts 45 and 46 are shown for final positioning and fastening. FIG. 10G is an isometric view of the hanger 42 and is also shown with hanging slots 52 and 53 along with clearance opening 54 for allowance of screw 35 to pass therethrough.
(93) FIG. 10H shows an alternate usage of hanger bracket 42 through the use of cable 47 and cable clamp 48.
(94) FIG. 10I shows screw 35 for fastening the duct section flanges 28 and hanger bracket 42.
(95) FIG. 10K provides and shows yet another alternative to hanging flanged duct sections with cable 47 and clamp 48 through the positioning of cable support hanger bracket 49 fastened between duct section flanges 28 with screw 35.
(96) FIG. 10M gives a view of a duct flange 14 having an inserted corner plate 28 with screw 35 in spaced apart axial alignment with section views CC and DD shown in place. FIG. 10M-1 is sectional view CC showing the endmost thread 301 of the threaded portion 32 along with the side 322 of threaded portion 32. FIG. 10M-2 is section DD showing opening 281 in corner plate 28 with locking interference area 301A created by endmost thread 301.
(97) FIG. 11 shows a partial view of aligned flanged duct sections 33, 34 with corner plate 37 shown with only one screw 35 in position for fastening to the mating duct section flange assembly 34 according to the invention, where the duct assembly will only use one screw 35 in each inserted corner plate 37 for fastening flanged duct sections 33, 34 without hanger brackets 42, 49. Slide on duct section flanges are also anticipated for use with this method of attaching duct sections together.
(98) FIG. 11A provides a partial view of aligned duct sections 33, 34 shown with three screws 35 in place to show an embodiment for use on large duct sections and for use with duct hanger brackets 42, 49. Corner plate 40 is shown with holes 351 for use with corner plate 40, 28, 37 having bent edges for retention in duct the flanges of duct sections 33, 34.
(99) FIG. 12 identifies area 55 with corner plates 28, 37 for use with one screw 35 and area 56 with corner plates 28, 40 for use with three screws 35 according to the invention. The duct section flanges also have openings 39 or dimples spacedly placed along the center of duct section flange 14 for positioning self drilling Tek screws 38 or other screws.
(100) FIGS. 13, 13A, and 13B are views of prior art slide on duct section flanges 57, using corner plates 58, 97 in a similar manner to integral duct section flanges 14 with inserted corner plates 37. Both systems use carriage bolt fastener 25 with a washer 27 and a nut 26 to connect duct sections.
(101) FIG. 14 is a drawing of a prior art slide on duct section flange 57 with space 62 for accepting the corner plate 37.
(102) FIGS. 15, 15A, and 15B show the large screw 35 and corner plates 37, 98 in a fully connected relationship of slide on flanges 57 being connected to duct sections 60 through the use of screws 38. Caulk gaskets 17A and 61A provide sealed relationship of the assembly at the ends of duct sections 60.
(103) FIG. 16 shows corner plate retention improvement 141 as a crimp or bend in the outer edge of duct section flange 14, as suspended via duct section hanging bracket 421 with downwardly depending leg 422. FIG. 16A provides a duct section hanger bracket 423 of a simplified style.
(104) FIGS. 17 and 17A show a spaced apart relationship of mating duct sections 33, 34 resulting from hanger bracket placement therebetween creating space 1. Pilot cone area 451 is shown in a final fastened position in the outermost corner plate hole. FIG. 17B shows the corner plate 28 and a section of duct section 14 bent at an area 2 by adjacent screw 35 in order to bring duct section flanges 33, 34 into sealed contact 1A.
(105) FIG. 18 is a view of duct end sections 33, 34 spaced apart by space 1 and in aligned relationship with gasket 22 in place for final sealing during fastening duct section flanges 14 together in sealed relationship. FIG. 19 provides an enlarged view of two duct section flanges 14 in aligned and spaced apart by space 1, with gasket 22 attached to one flange for fastening and sealing through the use of screw 35 without the need for drift pin 24 alignment and clamp 28.
(106) FIGS. 20, 20A show duct section flange 14 with inserted corner plates 28 being used to guide drill screws 31F, 31G for drilling, spacing and fastening duct sections 33 together in mating connection.
(107) FIGS. 20B, 20C show alternate drill screw styles 31D and 31E.
(108) FIGS. 21, 22, and 22A show screw 35 with alternate ends 31A, 31C and 31B as a threaded cone, cone end, and simple cylinder as alignment pilots. FIG. 22 shows the screw 35 threadedly engaged in corner plates 28 having pilot cone 31 and pilot threaded cone 31A as examples.
(109) FIG. 23 teaches single thread engagement 357 with one thickness of corner plate 28 with axis 355 of screw 35 tilted relative to the alignment axis 350 for threading therethrough. FIG. 23A shows a prior art hole for threading through corner plates, FIGS. 23B,C,D,E,F,G,H and FIG. 231 show alternative hole shapes for threading the screw through the corner plate without cutting threads. FIGS. 23B,E,C,F and FIG. 23G are preferred embodiments since they provide guiding when using a drill bit or self-drilling screw 233 as shown in FIG. 23J to pass through the integral duct flange 333 if it has no pre-existing opening. The use of hole 281 with combinations of edges 235 and contours 234 for forming hole shapes 232 that accommodate screw 35 for threadably passing there-through without the need to forcibly cut threads. Suitable shape holes can include, but are not limited to, square, obround, rectangle, rhombus, rounded rhombus, partially round in combination with square or rhombus or even trapezoidal through the use of the edges.
(110) FIG. 24 shows a prior art fastener having thread spacing about equal to the thickness of two corner plates 28 combined.
(111) FIG. 24A shows the prior art screw of FIG. 24 tilted 355 to accommodate two corner plates 28.
(112) FIG. 25 provides a view of the preferred embodiment corner plate 41 with holes 281 that will accommodate screws 35 or drill screws or bits as a drill guide.
(113) FIG. 26 shows a duct flange assembly with inserted corner plates clamping an alternative cable type bracket via a contoured locking washer 135.
(114) FIG. 26A is an end view of a serrated washer surface of a screw of the alternative cable type bracket and illustrating a manner of wrapping the cable about the screw.
(115) FIG. 27 is an end view of a duct section assembly and alternative cable hangers.
(116) FIG. 28 is an end view of a duct section assembly and an alternative cable hanging arrangement.
(117) FIG. 29 is a side view of an embodiment of a screw 35 of the invention, showing an alternative configuration of an endmost thread 1001 of a threaded portion 32 adjacent unthreaded space 30 of the screw.
(118) FIG. 30 is a fragmentary end view of a duct section assembly including inserted corner plates 1002 having corner apertures 1003 incorporating elements, such as bolt 1005, for connection to hanger brackets 1004.
(119) FIG. 31 is a sectional view of the duct section assembly of FIG. 30 including inserted corner plates incorporating elements for connection to hanger brackets, and showing a hanger bracket in connection therewith.
(120) FIG. 32 is a sectional view of the duct section assembly of FIG. 30 including inserted corner plates incorporating elements for connection to a hanger bracket, and showing an alternative hanger bracket in connection therewith.
(121) FIG. 33 shows a sheet metal nut 1006 of the invention, having a teardrop shape hole 281 therethrough. Nut 1006 can be placed against a second one of the inserted corner plates 28 of an assembly such as those discussed above, with hole 281 aligned with the aligned holes 351 through that and the first corner plate 28, such that the screw 35 can be threadedly engaged with hole 281 to retain or support the second corner plate 28. Nut 1006 is advantageous to back up and provide additional holding strength for the fastened connection, and also to replace direct threaded engagement with the second corner plate 28 in the event hole 351 thereof is stripped, damaged, or otherwise not usable or adequate for holding the corner plates together.
(122) In light of all the foregoing, it should thus be apparent to those skilled in the art that there has been shown and described a SYSTEM AND METHOD FOR JOINING AND HANGING DUCTS. However, it should also be apparent that, within the principles and scope of the invention, many changes are possible and contemplated, including in the details, materials, and arrangements of parts which have been described and illustrated to explain the nature of the invention. Thus, while the foregoing description and discussion addresses certain preferred embodiments or elements of the invention, it should further be understood that concepts of the invention, as based upon the foregoing description and discussion, may be readily incorporated into or employed in other embodiments and constructions without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown, and all changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.
