GB2360562A

GB2360562A - Duct piece with integral connector flange

Info

Publication number: GB2360562A
Application number: GB0016588A
Authority: GB
Inventors: Owen Michael Ferry
Original assignee: DUCTFORM VENTILATION
Current assignee: DUCTFORM VENTILATION
Priority date: 2000-07-07
Filing date: 2000-07-07
Publication date: 2001-09-26
Anticipated expiration: 2020-07-07
Also published as: GB0016588D0; GB2360562B

Abstract

A duct piece comprises a connector flange at at least one longitudinal end, the connector flange being formed integrally with the duct piece, and connectable directly to a second duct piece. The duct piece may be formed of a plurality of generally planar blank components, at least some of the blank components including portions which together form the integral flange in the assembled duct piece.

Description

1 2360562 1 Ductwork 2 3 The present invention relates to ductwork,

particularly 4 but not exclusively, to metal ductwork for carrying air 5 for applications such as warm air heating, cool air 6 supply and smoke and dirty air removal. 7 8 Methods of manufacturing ductwork of the type mentioned 9 above have evolved over a number of years. The 10 manufacturing processes that are used are essentially 11 derived from industry standards which specify 12 fabrications recommended for joints, shape stiffening, 13 etc. In the United Kingdom, the most commonly applied 14 industry standard is the latest May 1998 DW 144 of the Heating and Ventilation Contractors Association. 16 17 Ducting installations may have complex configurations 18 involving straight sections, branches, bends, offsets, 19 transitions (changes of cross section) etc. A variety 20 of different types of duct pieces may be required for a 21 given installation. The various duct pieces are 22 connected together to form a continuous duct of the 2 1 required configuration. Duct pieces other than 2 straight sections are generally referred to as 3 "transforming parts".

4 Ductwork can take many different shapes with 6 differently shaped cross sections. The most common 7 cross section is rectangular (including square). This 8 type of cross section can be employed to form any 9 required straight or transforming duct parts. Examples of typical ductwork transforming pieces are shown in 11 Figs. 1A to 1M of the attached drawings.

12 13 Ductwork pieces are typically fabricated from sheet 14 metal which is cut to predetermined shapes to form blanks which are folded, pressed, joined etc. to form 16 the required configuration of the duct piece.

17 18 The standard method of fabricating and assembling duct 19 pieces requires each duct piece to be formed with a straight neck portion at each end of the duct piece.

21 The neck portion is typically 50 mm in length and is 22 formed integrally with the duct piece as part of the 23 blanks from which the pieces are fabricated. In order 24 to connect transforming parts together, a separate flange frame connector is fixed to each neck portion, 26 whereby adjacent duct pieces may be connected, e.g. by 27 bolting through adjacent flanges or welding etc.

28 29 This method provides a reliable means for connecting together ductwork, but the requirement for neck 31 portions on the duct pieces and for separate flange 3 1 connectors makes it expensive to fabricate and assemble 2 in terms of time, materials and labour. 3 4 It is an object of the present invention to provide 5 improved ductwork pieces and processes for 6 manufacturing ductwork. 7 8 In accordance with a first aspect of the invention, 9 there is provided a duct piece having a connector 10 flange formed integrally therewith at at least one 11 longitudinal end thereof. 12 13 Preferably, the integrally formed flange is connected 14 directly to the wall panels of the duct. Such a is connection means that there is no need to include a 16 straight neck piece at each of the ends of the duct 17 piece. 18 19 Preferably, the duct piece is formed from a plurality 20 of generally planar blank components, at least some of 21 said blank components including portions which together 22 form said integral flange in the assembled duct piece. 23 24 Preferably, the duct piece comprises a transforming 25 duct piece (as defined herein). The transforming piece 26 may comprise, but is not limited to, any of the types 27 of duct piece illustrated in the drawings attached 28 hereto. 29 30 In accordance with a second aspect of the invention, 31 there is provided a method of forming a duct piece, 32 comprising the step of forming a plurality of generally 4 1 planar blank components having predetermined shapes, at 2 least some of which include portions adapted to form an 3 integral connector flange when the components are 4 assembled to form a duct piece.

6 Preferably, the integral flange is provided on a 7 transforming duct piece.

8 9 In accordance with a third aspect of the invention, 10 there is provided computer controlled manufacturing 11 apparatus programmed for the purpose of producing blank 12 duct components and/or duct pieces in accordance with 13 the first and second aspects of the invention. 14 is In accordance with a fourth aspect of the invention, 16 there is provided a computer program adapted to control 17 the operation of computer controlled manufacturing 18 apparatus for the purpose of producing blank duct 19 components and/or duct pieces in accordance with the 20 first and second aspects of the invention.

21 22 Embodiments of the present invention will now be 23 described, by way of example only, with reference to 24 the accompanying drawings in which:

26 Figs.1A-M show plan views of a variety of conventional 27 duct pieces formed using standard manufacturing methods 28 and Figs.2A-M show plan views of corresponding duct 29 pieces made in accordance with the present invention; 31 Fig.3A shows component blanks used to produce parts for 32 a rectangular to round duct piece made in accordance 1 with the standard manufacturing technique, Fig. 3B 2 shows corresponding blanks used to produce parts for a 3 similar duct piece made in accordance with the present 4 invention and Fig. 3C shows the completed duct piece; 6 Fig. 4A shows component blanks for the standard method 7 of making a radius bend duct piece, Fig. 4B shows 8 corresponding blanks for making a similar duct piece in 9 accordance with the present invention and Fig. 4C shows the completed duct piece; 11 12 Fig. SA shows component blanks for the standard method 13 of making an angled offset duct piece, Fig. 5B shows 14 corresponding blanks for making a similar duct piece in is accordance with the present invention and Fig. SC shows 16 the completed duct piece; 17 18 Fig. 6A shows component blanks for the standard method 19 of making a mitred offset duct piece, Fig. 6B shows corresponding blanks for making a similar duct piece in 21 accordance with the present invention and Fig. 6C shows 22 the completed duct piece; 23 24 Fig. 7A shows component blanks for the standard method of making a bellmouth duct piece, Fig. 7B shows 26 corresponding blanks for making a similar duct piece in 27 accordance with the present invention and Fig. 7C shows 28 the completed duct piece; 29 Fig. 8A shows component blanks for the standard method 31 of making a shoe branch duct piece of circular cross 32 section, Fig. 8B shows corresponding blanks for making 6 1 a similar duct piece in accordance with the present 2 invention and Fig. 8C shows the completed duct piece; 3 4 Fig. 9A shows component blanks for the standard method 5 of making a shoe branch duct piece of rectangular cross 6 section, Fig. 9B shows corresponding blanks for making 7 a similar duct piece in accordance with the present 8 invention and Fig. 9C shows the completed duct piece; 9 10 Fig. 10A shows component blanks for the standard method 11 of making a breeches duct piece, Fig. 10B shows 12 corresponding blanks for making a similar duct piece in 13 accordance with the present invention and 10C shows the 14 completed duct piece; is 16 Fig. 11A shows component blanks for the standard method 17 of making a concentric reducer duct piece, Fig. 11B 18 shows corresponding blanks for making a similar duct 19 piece in accordance with the present invention and Fig.

11C shows the completed duct piece; 21 22 Fig. 12A shows component blanks for the standard method 23 of making an eccentric reducer duct piece, Fig. 12B 24 shows corresponding blanks for making a similar duct piece in accordance with the present invention and Fig.

26 12C shows the completed duct piece; 27 28 Fig. 13A shows component blanks for the standard method 29 of making an offset taper duct piece and Fig. 13B shows corresponding blanks for making a similar duct piece in 31 accordance with the present invention and Fig. 13C 32 shows the completed duct piece; 7 2 Fig. 14A shows a template for the standard method of 3 making a rectangular to oval duct piece, Fig. 14B shows 4 corresponding blanks for making this duct piece in 5 accordance with the present invention and Fig. 14C 6 shows the completed duct piece; and 7 8 Fig. 15A shows component blanks for the standard method 9 of making a Y duct piece, Fig. 15B shows corresponding 10 blanks for making a similar duct piece in accordance 11 with the present invention and Fig. 15C shows the 12 completed duct piece. 13 14 Embodiments of improved duct pieces and methods of 15 manufacturing ductwork in accordance with the present 16 invention will now be described. 17 18 Figs. 1A to 1M illustrate a variety of conventional 19 duct transforming pieces, each of which can be seen to 20 include a straight neck portion 10 and a separate 21 flange connector 12 at at least one end of the piece. 22 By comparison Figs. 2A to 2M illustrate corresponding 23 pieces formed in accordance with the present invention, 24 which completely or partially eliminate the need for 25 neck portions and which include flanges 16 formed 26 integrally with the remainder of the duct piece (i.e. 27 the material which forms the flanges 16 is formed 28 integrally with the sheet metal blanks from which the 29 pieces are fabricated) 30 31 In order to fabricate a duct piece having a 32 predetermined configuration, a duct piece design is 8 1 worked up using either traditional drawing methods or 2 computer aided design (CAD) to define the shapes of 3 planar blank components which can be cut from sheet 4 material and shaped and assembled to form the required duct piece. The blanks can be cut using physical 6 templates or, preferably, using computer controlled 7 cutting apparatus programmed to define the required 8 shapes of the blanks.

9 Figs. 3-15A show the shapes of the conventional sheet 11 metal blanks employed in fabricating some of the duct 12 pieces illustrated in Figs. 1A to 1M. Figs. 3B-15B 13 illustrate the shapes of corresponding sheet metal 14 blanks employed in fabricating the corresponding duct pieces of Figs. 2A to 2M, in accordance with the 16 present invention. Figs. 3C-15C show the shape of the 17 corresponding duct pieces.

18 19 The blanks of Figs. 3A-15A include portions 20 which, when the blanks are assembled, form the neck portions 21 10 of the conventional duct pieces. In the blanks of 22 Figs. 3B-15B, these portions are omitted and replaced 23 by portions 30 which, when the blanks are assembled, 24 form the integral flanges 16 of the improved duct pieces in accordance with the present invention. The 26 portions 30 will generally be smaller than the portions 27 20 (the integral flanges 16 typically being about 25 - 28 35 mm in width and the conventional neck portions 10 29 typically being about 50 mm in length). Accordingly, there is a reduction in the amount of material required 31 to form the blanks in accordance with the invention.

9 1 Also, the need for separate flange components is 2 eliminated.

3 4 In Figs. 4a and 4b, the neck portion 42 shown in blank 5 44 has been replaced by a flange forming section 43 in 6 blank 49 of the radius bend duct piece. Similarly, 7 Fig. 4c shows the completed duct piece. 8 9 In Figs. 5a and 5b, the neck portion 52 shown in blank 54 has been replaced by a flange forming section 53 in 11 blank 59 of the angled offset duct piece. Fig. Sc shows 12 the completed duct piece.

13 14 In Figs. 7a and 7b, the neck portion 73 shown in blank 72 has been replaced by a flange forming section 75 in 16 blank 74 of the bellmouth duct piece. Fig. 7c shows the 17 completed duct piece.

18 19 In Figs. 8a and 8b, the neck portion 81 shown in the blank 82 has been replaced by a flange forming section 21 89 in blank 86 and the neck piece 85 has been replaced 22 by a flange forming section 83 in blank 88 of the 23 bellmouth duct piece. Fig. 8c shows the completed duct 24 piece. 25 26 In Figs. 9a and 9b, the neck portion 93 shown in the 27 blank 92 has been replaced by a flange forming section 28 95 in blank 98 of the shoe branch from rectangular 29 section duct piece. Correspondingly, blank 96 is 30 thinner than blank 94. Fig. 9c shows the completed duct 31 piece. 32 1 In Figs. 10a and lob, the neck portions 101 shown in 2 the blank 102 have been replaced by a flange forming 3 section 112 in blank 108 and the neck pieces 103 and 4 111 in blank 104 have been replaced by a flange forming sections 113 and 115 in blank 109 of the breeches duct 6 piece. Fig. 10c shows the completed duct piece.

7 8 In Figs. lla and lib, the neck portion 128 shown in the 9 blank 120 has been replaced by a flange forming section 121 in blank 124 and the neck pieces 122 and 127 in 11 blanks 125 have been replaced by a flange forming 12 section 117 and 119 in blanks 124 of the concentric 13 reducer duct piece. Fig. llc shows the completed duct 14 piece.

is 16 In Figs. 12a and 12b, the neck portions 132 shown in 17 the blank 130 has been replaced by a flange forming 18 section 131 in blank 137 of the eccentric reducer duct 19 piece. Fig. 12c shows the completed duct piece.

21 In Figs. 13a and 13b, the neck portions 141 and 143 22 shown in the blanks 140 has been replaced by a flange 23 forming section 141a in blank 148 and the neck pieces 24 145 shown in the blanks 142 has been replaced by a flange forming sections 145a and 146a in blanks 146 of 26 the offset taper duct piece. Fig. 13c shows the 27 completed duct piece. 28 29 In Figs. 14a and 14b, the neck portion 152 shown in the 30 blanks 150 has been replaced by a flange forming 31 section 156 in blanks 154. Fig. 14c shows the completed 32 duct piece.

1 In Figs. 15a and 15b, comparison of sections 162 and 2 164 of Fig. 15a with blanks 168 and 170 respectively of 3 15b clearly show that less material is used in the 4 blanks made in accordance with the present invention. 5 The neck portions 165 shown in the blanks 166 have been 6 replaced by a flange forming section 175 in blanks 172. 7 8 The sheet metal blanks are assembled together to form 9 the duct piece by conventional techniques such as snap 10 locking the pieces together or by use of a technique 11 called snap or lock form or by spot welding/metal 12 clinching the pieces together. 13 14 In accordance with the present invention, the integral is flanges 16 are formed by inserting the duct piece into 16 a machine which bends or rolls the portions 30 of the 17 duct piece to the required angle (usually substantially 18 900) with respect to the surface of the remainder of 19 the blank. 20 21 It will be appreciated that the portions 16 can be bent 22 to the required angle either before the duct piece is 23 assembled from its component blanks or afterwards. 24 25 As can be seen from Figs 2A-2M the angle between the 26 flange and the duct piece may require to be adjusted on 27 some faces depending on the shape of the duct piece, 28 as, for example, in the cases of Figs. 2B (angled 29 offset), 2C (mitred offset) and 21 (offset taper). 30 31 In each of these cases, if all of the flange portions 32 16 are initially bent to an angle of 900 with respect 12 1 to the surf ace of the remainder of the respective 2 blank, the flange portions of the top and bottom 3 surfaces (as seen in the drawings) require to be bent 4 further in order that all of the flange portions are substantially co-planar. Such final adjustment of the 6 flange portions may be performed manually, by eye, 7 after assembly of the duct piece or at the point of 8 installation, thereby reducing the time and labour 9 involved in conventional machining, flattening, dressing etc.

11 12 The following tables provide information on the typical 13 time savings which may be achieved through use of the 14 present invention in comparison to a prior art method is of duct formation. The process steps and the number of 16 times each step is repeated are provided.

17 18 ANGLED OFFSET - Prior Art 19 20

Manufacturing Step Time Processes Total Time 1 Form Snaplock 11 secs 4 times 44 secs pocket along edge of a duct piece panel 2 Fold edge of 4 secs 4 times 16 secs straight section for edger.

3 Add lomm tail along 7 secs 4 times 28 secs edge of the panel 4 Add Button shaped 9 secs 4 times 36 secs indentation in 1Omm tail of duct piece panel to fit with snaplock pocket.

Turn out integrated 10 secs 8 times 80 secs flange on the duct piece Bend panels to 10 secs 4 times 40 secs prescribed angle 113 13 7 Chap up flange with 22 secs 4 times 88 secs a hammer to square off flange 8 Fit Corners of the 4 secs 8 times 32 secs duct piece 9 Crimp Corners of the 8 secs 8 times 64 secs duct piece Crimp Corners of the 4 secs 8 times 32 secs duct piece 1 2 TOTAL PROCESSES 56 TOTAL TIME 7 MINS 40 SECS 3 4 ANGLED OFFSET Present Invention 6 7 Manufacturing Step Time Processes Total Time 1 Form Snaplock 11 secs 4 times 44 secs pocket along edge of a duct piece panel 2 Add Button shaped 11 secs 4 times 44 secs indentation in lomm tail of duct piece panel to fit with snaplock pocket.

3 Turn out integrated 10 secs 8 times 80 secs flange on the duct piece 4 Chap up flange with 13 secs 4 times 52 secs a hammer to square off flange Square off flanges 2 secs 4 times 8 secs 6 Fit Corners of the 4 secs 8 times 32 secs duct piece 7 Crimp Corners of the 7 secs 8 times 56 secs duct piece 8 Dress Corners of 4 secs 8 times 32 secs the duct piece 8 9 TOTAL PROCESSES 48 TOTAL TIME 5 MINS 48 SECS 11 12 14 2 ECCENTRIC REDUCER - Prior Art 3

Manufacturing Time Processes Total Step Time 1 Form Snaplock 7 secs 4 times 28 secs pocket along seam of duct piece 2 Fold edge of 3 secs 4 times 12 secs straight section for edger.

3 Add 1Omm tail 10 4 times 40 secs along edge of the secs panel 4 Add Button shaped 8 secs 4 times 32 secs indentation in lomm tail of flange to fit with snaplock pockets.

Turn out 20 2 times 40 secs integrated flange secs on the small side of the duct piece 6 Turn out 11 6 times 66 secs integrated flange secs on the long side of the duct piece 7 Fold duct piece 14 4 times 56 secs secs 8 Chap Up duct is 4 times 60 secs piece secs 9 Fit Corners of 4 secs 8 times 32 secs duct piece rimp Corners of 6 secs 8 times 48 secs duct piece 4 TOTAL PROCESSES 48 TOTAL TIME 6 MINS 54 SECS 6 is 2 3 4 ECCENTRIC REDUCER - Present Invention 6 Manufacturing Time Processes Total Step Time 1 Form Snaplock 7 secs 4 times 28 secs pocket along seam of duct piece 2 Add Button shaped 7 secs 4 times 28 secs indentation in lomm tail of flange to fit with snaplock pockets.

3 Chap Down edges 3 secs 4 times 12 secs of integrated flange 4 Turn out 20 2 times 40 secs integrated flange secs on the small side of the duct piece panel Turn out 11 6 times 66 secs integrated flange secs on the small side of the duct piece panel 6 Chap Up duct 10 4 times 40 secs piece secs 7 Fit Corners to 4 secs 8 times 32 secs duct piece 8 Crimp Corners of 6 secs 8 times 48 secs duct piece 7 8 TOTAL PROCESSES 40 TOTAL TIME 4 MINS 54 SECS 9 Duct pieces made in accordance with the present 11 invention require fewer process steps and therefore 12 take less time to make. In addition, the absence of 13 the straight section in the present invention means 16 1 that it is easier and therefore quicker to chap up the 2 flange to square it off.

3 4 The following table illustrates the improvement in efficiency of manufacture of duct pieces using the 6 present invention in comparison with the above prior 7 art method of manufacturing ductwork.

8 9 Prior Prior Present Present Time Art: art: Inventio Invention Saved Method Total n: Time: Total Time Method (mins:se Method (mins:s Steps c) Steps ec) Rectangular 5: 28 44 5:14 44 4.3 to Round Radius 6:02 46 5:45 42 4.7 Bend Angled 7:40 56 5:48 42 28.7 Offset Mitred 8:04 52 6:40 50 17.4 Offset Bellmouth 7:50 so 6:20 42 19.1 Shoe Branch 3:36 22 3:04 20 14.8 Circular Duct Shoe Branch 3:28 21 3:12 23 7.7 Rectangular Duct Breeches 14:55 77 11:35 69 22.3 Piece Concentric 14:24 88 6:44 40 53.2 Reducer Eccentric 6:54 48 4:54 40 29.0 Reducer Off Set 16:46 90 6:08 so 59.4 Taper Square to 5:28 65 5:14 44 4.3 Round Y Piece 8:48 75 7:52 65 10.6 11 12 17 1 It will be appreciated that the present invention, by 2 providing a flange which is integrated into and part of 3 the rest of the duct piece and removing the straight 4 neck section, is cheaper and quicker to manufacture than conventional duct pieces.

6 7 The invention also includes computer controlled machine 8 tools programmed for the purpose of producing blank 9 duct components and/or duct pieces in accordance with the invention, and computer programs therefor.

11 12 Improvements and modifications may be incorporated 13 without departing from the scope of the invention.

14 is 16 17 18 19 2 0 P25738-Specl.doc 21

Claims

CLAIMS ig

2 3 1 A duct piece having a connector f lange at at 4 least one longitudinal end thereof, said connector flange being formed integrally with the ductpiece 6 wherein the integral flange is connectable directly 7 to a second duct piece.

8 9
2. A duct piece as claimed in Claim 1, wherein the duct piece is formed from a plurality of generally 11 planar blank components, at least some of said blank 12 components including portions which together form 13 said integral flange in the assembled duct piece.

14
3. A duct piece as claimed in any preceding claim, 16 wherein, the duct piece comprises a transforming duct 17 piece which may comprise, but is not limited to, any 18 of the types of duct piece illustrated in the 19 drawings attached hereto.

21
4. A duct piece as hereinbefore described with 22 reference to the accompanying drawings.

23 24
5. A method of forming a duct piece, comprising the step of forming a plurality of generally planar blank 26 components having predetermined shapes, said blanks 27 having a first section and a second section, wherein 28 at least part of said second section of said blank is 29 adapted to form an integral connector flange when the components are assembled to form a duct piece.

31 i Cl 1
6. A method of forming a duct piece as claimed in 2 Claim 5 wherein the at least part of the second 3 section is bent to a predetermined angle with respect 4 to said first section in order to form the integral connector flange.

6 7
7. A method as claimed in Claim 5 or Claim 6 8 wherein, the integral connector flange is provided on 9 a transforming duct piece.

11
8. A method of forming a duct piece as hereinbefore 12 described with reference to the accompanying 13 drawings.

14
9. A computer controlled manufacturing apparatus 16 programmed for the purpose of producing blank duct 17 components and/or duct pieces in accordance with the 18 first and second aspects of the invention.

19
10. A computer program adapted to control the 21 operation of computer controlled manufacturing 22 apparatus for the purpose of producing blank duct 23 components and/or duct pieces in accordance with the 24 first and second aspects of the invention.

2P Amendments to the claims have been riled as follows 2 3 1. A transforming metal sheet duct piece for 4 connecting together rectangular section metal duct pieces, the transforming metal sheet duct piece 6 formed from at least one planar sheet metal blank 7 component, the transforming duct piece having an 8 opening at at least one longitudinal end thereof and 9 at least one side wall, the opening defining a plane, such that the at least one side wall meets the plane -11 of the opening non-orthogonally, the transforming 12 metal sheet duct piece having at least one connector 13 flange at the at least one longitudinal end thereof,

14 said connector flange being formed integrally from is the sheet metal blank and being connected directly to 16 said at least one side wall of the ductpiece such 17 that the connector flange has a connector section 18 that is directly connectable to a second ductpiece, 19 the connector section being substantially coplanar with the opening.

21 22 2. A transforming metal sheet duct piece 23 substantially as hereinbefore described with 24 reference to Figures 2, 3B, 4B, 5B, 6B, 7B, 8B, 9B, 25 10B, 11B, 12B, 13B, 14B or 15B. 26 27 3. A method of forming a transforming metal sheet 28 duct piece, comprising the step of forming a 29 plurality of generally planar blank components having predetermined shapes, said blanks having a first 31 section and a second section, wherein at least part 2, S 1 of said second section of said blank is adapted to 2 form an integral connector flange when the components 3 are assembled to form a transforming duct piece as 4 defined in Claim 1.

6 4. A method of forming a transforming metal sheet 7 duct piece as claimed in Claim 3 wherein the at least 8 part of the second section is bent to a predetermined 9 angle with respect to said first section in order to form the integral connector flange.

11 12 5. A method of forming a transforming metal sheet 13 duct piece substantially as hereinbefore described 14 with reference to Figures 2, 3B, 4B, 5B, 6B, 7B, 8B, is 9B, 10B, 11B, 12B, 13B, 14B and 15B.

16 17 6. A computer controlled manufacturing apparatus 18 programmed to perform the method of claim 3.

19