US 2275572 A
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Description (OCR text may contain errors)
March 10, 11%42. w a SOMERs 2,275,5Y2
PREFABRICATED CGNDUIT Filed May 2, 1939 4 sheets-sneak 1 Mi'llkna-smew's,
March 10,1942. w. s. SOMERS 2,275,572
PREFABRIGATED CONDUIT Filed May 2, 1959 4 Sheets-Sheet 2 qyigy.
March 10, 1942. w. SOMERS 2,275,572.
PREFABRI CATED CONDUIT Filed May 2, 1959 4 Sheets-Sheet 4 (34 1920. V MW 54 17/121 8. Sent-8B,
Patented Mar. 10, .1942
,UNITED STATES PATENT OFFICE 2,275,572 PREFABRICATED CONDUIT William S. Somers, Columbus, Ohio Application May 2, 1939, Serial No. 271,416
This invention relates. to the sheet metal art and is particularly directed to the formation of sheet metal conduits for the transfer of heating and cooling mediums employed in air conditioning systems for buildings. Prior to this invention, when air conditioning systems were being installed, it was necessary for a sheet metal worker to cut, form and fit certain of. the required conduits at the time and place of installation. These operations usually require a considerable amount of time and greatly increase the final cost of the system. 7
The primary object of the present invention resides in the provision of sheet metal duct forming means which may be completely constructed at the factory in stock sizes, shippedv in a knockclown condition, and assembled at the location of the installation without alteration.
A further object rests in providing improved conduit sections and coupling members therefor which are simple to manufacture and can be quickly and easily assembled to produce substantially air-tight ducts.
Another object is the provision of a conduit forming section which can be manufactured in a plurality of standard sizes from combinations of which a large number of conduits of different sizes may be produced, the number of sizes being further increased by performing slight alterations consisting of straight cutting operations on the standard sections.
A still further object resides in the formation of conduit forming sections which may be stacked or nested to conserve space during shipping and storage prior to use.
It is also an object to form a sectional conduit, having completely closed longitudinally extending corners and means for connecting the sections. without the use of tools, screws or other equipment.
Other objects will be apparent from the following description and the accompanying drawings. in which the invention has been illustrated in detail.
Fig. 1 is a perspective view of a. portion of a duct formed in accordance with the present invention;
Fig. 2 is a vertical transverse sectional View taken through the duct shown in Fig. 1;
Fig. 3 is a similar view illustrating how the size of the duct may be reduced by a simple cutting operation;
Fig. 4. is a detail sectional View taken through the joint between the flanges of a pair of conduit forming members;
Fig. 5 is a similar view of a slightly modified form;
Fig. 5a, is a similar View of a further modified form;
Fig. 6 is a vertical longitudinal sectional View taken through the joint between a pair of duct sections, the plane of this figure being indicated by the line VI-VI of Fig. 1;
Fig. '7 is a similar View of a slightly modified form of connecting member;
Fig. 7a is a similar view of a further modified form of connecting member;
Fig. 8 is a plan view of a portion of a duct having a reducer positioned therein;
Fig. 9 is a similar View showing a reducer having one straight side;
Fig. 10 is a similar View showing an increaser provided with a plurality of take-off fittings;
Fig. 11 is a horizontal sectional view taken through the conduit at the point where a takeoff is connected thereto;
Fig. 12 is a detail sectional view taken on the plane indicated by the line XII-XII of Fig. 8;
Fig. 13 is a plan view of a portion of a large size conduit constructed of sections embodying a modified form of the invention;
Fig. 14 is a transverse sectional view on the plane indicated by the line XIVXIV of Fig. 13;
Fig. 15 is a perspective View of the complemental ends of a pair of coupling bars in a separated condition;
Fig. 16 is a plan view of a trunk conduit provided with a plurality of reducing sections, the latter members having take-off fittings connected therewith;
Fig. 17 is a horizontal. sectional View taken through an increaser or reducer and a take-cit fitting connected therewith;
Fig. 18 is a transverse vertical sectional view of a modified form of conduit;
Figs. 19 and 20 are transverse sectional views taken through the seams between the conduit sections showing different methods by which the sections may be locked in assembled relation.
Referring more particularly to the drawings, the numeral l designates a conduit formed from sections 2. constructed in accordance with the present invention. Each section 2 is formed to include a pair of channel-shaped members 3' arranged with the open sides toward one another. The members 3 include vertical side walls 4 and horizontal walls 5 and 6. When one of the channel members is turned to position the open side toward that of the. other channel, the wall 6 is brought into registration with the wall 5 of the second member. The free edge of the wall 6 is folded upon itself a plurality of times, as indicated at l, to form a longitudinally extending groove at the outer edge of the flange. The folded portion is offset by bending the flange as at 8 to position the channel in alignment with the flange 6. The outer edge of the flange 5 is plain and unfolded in order that it may be inserted in the groove in flange 6 when the members are assembled. The channel members are held in their assembled relation by a coupling member 9 which is formed from a plurality of bars It and II of different lengths. The bars H are disposed at the sides of the conduit and connect the side walls 4 of the sections.
As illustrated in Fig. 6, the bars It and H are formed of inner and outer strips [2 and I3 welded or otherwise joined along their longitudinal axis. The side portions of the strip I3 are oifset as at M to space them from the outer edge portions of the strip l2. This construction provides the barwith longitudinally extending channels at the side edges for the reception of the ends of the conduit sections. The edges of the strip l2 are turned under as at 55 to provide inwardly directed shoulders which engage spring tongues it formed at the ends of the channel members 3. The seam produced by the formation of the groove in the flanges 6 is relieved at the ends of the members 3 to accommodate'the bars it). Prior to fastening the bars H) and III to the conduit section, these members are connected at their ends to form an endless collar or coupling, after which they are applied to an end of the assembled channel members.
The bars H are provided With angularly directed tongues lia'at their ends which, when the bars are assembled into collar forming position, enter the ends of the bars and a spring lug lib formed on the tongue snaps into an opening la in the bar It] as shown in Fig. 12. When this occurs, the bars will be securely held in assembled relation. They may be disassembled when desired by raising the portion of the bar immediately in front of the lug lib to permit it to be released from the shoulder provided by the edge of the opening.
The application of the collar is facilitated by starting one corner of one end of the duct section in the groove of the collar and following around the duct one side at a time. After the end of the duct has been started intothe groove, the collar may be permanently attached to the section by pushing the members together until the spring tongues on the members 3 snap behind the shoulders formed in the groove. Usually when the duct is being assembled, the channelshaped members are connected to form a section, then a collar is applied to one end of each section. When the sections are assembled to form the duct, the plain ends of the sections are slipped into the grooves of the collars on the other sections.
In certain instances, the members 3 are formed as shown in Fig. 3 wherein the flange is short, thus positioning the seams at the longitudinal corners of the conduit. When this type of duct forming section is employed, the bars from which the collars are formed may be attached directly to the ends of the members and shipped therewith; After assembly, the edges ofthe flanges 5 are inserted inthechannels of the seams on flanges ti and the sections pushed together and the'bars l0 and H will be fastened by snap locks formed at the ends thereof.
In Figs. 8, 9 and 10, there has been illustrated different types of fittings formed from conduit sections constructed in accordance with the invention. These fittings embody one or more expanding or reducing sections [1 which correspond to the channel members 3 except that the depth of the channel varies from one end to the other. When two of the sections are placed together as shown in Fig. 8, a center increaser or reducer is produced. The edges of the flanges of the sections I! correspond with those on the channel members 3 and one of the latter members may be combinedwith one of the former to produce a straight side increaser or reducer. As illustrated, the degree of variation in depth of the members I! may be changed according to the change in size of the conduit.
In Fig. 10, a center increaser has a plurality of take-off connections secured to its larger end. Any desirable take-ofi fitting may be used at this point but for purposes of illustration, a top takeoff fitting I8 is provided at one side while a side take-off fitting i9 is connected at the other side. Between these fittings, a straight duct l continues on from the increaser.
Fig. 11 shows the connections between a takeoff fitting, an increaser and a straight duct I leading from the increaser. The side wall of the straight duct section has a U-shaped strip 20 connected at its edge. This strip receives the forward edge of the inner side wall of the takeoff fitting and prevents the escape of air through the space between these members. The other edges of the take-off fitting are connected with the end of the increaser by the usual collar formed from the bars I0. In this type of connection, the straight duct section is joined with the collar only at the top and bottom.
In Fig. 13, an extra large conduit provided with a center increaser has been illustrated. This large conduit is constructed from parts corre sponding to those employed in making the conduit I but these parts are separated by substantially flat sheets 2| positioned between the flanges of the channel members 3.
As illustrated in Fig. 14, the plates 2| have one plain side edge and one provided with a longitudinally extending groove identical with that formed on the flange 6 of the channel member 3. The plain edge of the plate 2! is positioned in the groove provided at the edge of the-member 3. This produces a Wide duct from the standard parts used in the conventional ducts merely by the addition of the flat plates 2!. To strengthen this large duct longitudinally, the folded edge of the flange 6 has an upwardly directed rib 22 pr0- vided at the edge of the groove by continuing the metal upwardly and terminating'it in a downward extension. This type of seam has been illustrated in Figs. 5 and 14.
The collar members used with this type of duct are also strengthened by the addition of avertical rib 23 illustrated in Figs. '7 and 14. This rib may be formed from separate strips attached to the bars H] or it may be formed by doubling the strip 12 in the middle and then flattening the side portions to provide flanges. This rib maybe provided at its ends with openings 24 through which wires or other securing devices may be passed to anchor the conduit to an overhead support. When the collarsectionsare provided with the longitudinally extending reenforcingrib, the openings for the reception of the spring means on the side bars are positioned at either side-of the longitudinal center of the bars. Otherwise,
these collars are identical in construction with the standard collar illustrated in Figs. 6 and 15. The bar shown in Fig. 7 has the lower plate formed from an unfolded strip of material while the upper bar is bent downwardly at its longi tudinal center to provide the spacing at the side edges of the strips. By this provision, the inner surface is devoid of shoulders which would interfere with the flow of air through the conduit.
In Fig. a, the conduit section having the groove formed at its edge has all the material disposed at one surface of the flange. In other words, when the material is folded upon itself to form the groove, the flange is not bent as in the preferred form but is permitted to remain fiat until the first fold at the edge 'of the groove is formed. The free edge of the opposite flange is ofiset as at 25 to provide the conduit formed by the joining of these two sections with a smooth inner wall which will. cause no interference with the air passing therethrough.
In Fig. 7a, a connecting bar for the ends of the conduit section has been provided from a single strip of sheet metal. In this form of connecting member, the strip is doubled as at 26 and the por tions folded under or rebent as at 21 to form the inner flanges 28 of the connecting bar. The flanges 28 are spaced from the body of the bar formed by folding the bar at 26 to provide grooves for the ends of the conduit sections connected therewith. The body of the bar is formed with perforations adjacent the edges of the groove to receive the spring tongues formed on the conduit sections. If desired, this type of bar may be welded along the folded portion at 2'! to make the bar more rigid.
. In Fig. 16, the trunk conduit 29 is provided with'a plurality of reducers 36. At its widest portion, the trunk line is provided with a top take-off connection3l leading to one side of the conduit. Each reducer has an angular take-off fitting 32 or 33 secured thereto. As shown in Fig. 1'7, the take-on fittings have one end provided with a peripheral flange through which screws extend to hold the fitting with the side wall of the reducer. The flanges are spaced slightly from the end of the take-off fitting to permit this end to enter the reducer through an opening formed in the side wall.
In Fig. 18, a conduit has been illustrated in which there has been formed a pair of duplicate sections 34 which are spaced by plain fiat plates 35. The sections 34 are channel shaped and have the free edges of each flange provided with grooves formed in the same manner as the groove on the flange 6 of the preferred form of conduit. The edges of the material from which the groove is formed are provided with the reenforcing ribs which serve to strengthen the conduit and to prevent longitudinal flexing.
In Figs. 19 and 20, there has been shown several methods of securing the conduit sections to one another. In Fig. 19, the free edge of one fiange has the usual groove formed therewith. One wall of. the groove has an opening 35 formed therein through which a tongue 31 provided on the flange of the other section extends. This tongue is bent back to provide a hook which will lock the sections in assembled condition.
In Fig. 20, the plain flange has a rearwardly directed spring tongue 38 thereon to engage the edge of the opening formed in the wall of the groove on the other flange. These methods of securing the conduit sections together are employed when it is desired to make the conduit 1. In a sheet metal duct of the type having a plurality of tubular sections, means for connecting the ends of the sections comprising a coupling formed of a plurality of bars, each of which has a longitudinally extending groove in each side edge, cooperative means provided on said bars for detachably connecting the ends thereof to.
form an endless collar, and inwardly directed shoulders formed on said bars within said grooves.
2'. In a sheet metal duct of the type having a pair of tubular sections, coupling means for connecting said sections comprising a plurality of bars each of which is formed from a pair of strips joined along thelongitudinal axes thereof, the side edges of the strips being spaced to provide a groove at each longitudinal edge of said'bar, certain of said bars being provided with a socket at each end, and tongue means formed at the ends of the other bars for reception by the sockets in the first bar.
3. In a sheet metal duct of the type having a pair of tubular sections, coupling means for connecting said sections comprising a plurality of barseach of which is formed from a pair of strips joined along the longitudinal axes thereof, the side edges of the strips being spaced to provide a groove at each longitudinal edge of said bar, certain of said bars being provided with a socket at each end, shoulder means formed on the last-mentioned bars at one side of each socket, tongue means formed at the ends of the other bars for reception by the sockets in the first bars, and lug means projecting from said tongue means for engagement with said shoulders to resist separation of said bars.
4. In combination with a sheet metal duct of the type having a pair of tubular sections, coupling means for connecting said sections comprising a plurality of bars each of which is formed from a pair of strips adapted to be det-achably connected at their ends to form a collar, one of said strips having the longitudinal side portions offset with respect to the central portion of said strip, said central portion being secured to the central portion of the second strip, the side edges of said second strip being folded under upon said strip, the offsetting of the side portions of said first strip providing the bar with a groove at each side, the folded portions of said second bar providing inwardly directed shoulders in said grooves.
5. In a sheet metal duct of the type having a pair of tubular sections, each section being composed of a pair of oppositely arranged channellike members having interfitting longitudinal edges, coupling means for connecting the sections and preventing separation of the members of eachsection comprising a plurality of bars, each of which has a longitudinally extending groove at each longitudinal edge for the reception of an end edge of one of said tubular sections, means disposed in said grooves for holding the section edges therein to prevent the release of said sections from said bars, and interlocking means formed on the complemental ends of said bars, connection of the ends of the bars providing an endless collar and preventing separation of the channel members of said sections.
6. In a sheet metal duct of the type having a pair of tubular sections, coupling means for connecting said sections comprising a plurality of bars each of which is formed from a pair of strips joined along the longitudinal axes thereof, the side edges of the strips being spacedto provide a groove at each longitudinal edge of said bar, and cooperative means provided on said bars for detachably connecting the ends thereof to for an endless collar. V
7. 'Ina sheet metal duct of the type having-a pair of duplicative' separable sections provided with means on the adjoining longitudinal edges thereof to effect their connection to form a conduit, means detachably secured to the ends of said sections to prevent separation thereof, said means comprising a plurality of bars each of which is formed from a pair of strips joined along the longitudinal axes thereof, the side edges of said strips being spaced to provide a groove at each longitudinal edge of said bar, and cooperative means provided on said bars vfor detachably connecting the ends thereof to form an endless collar.
8. In a sheet metal duct system, a pair of oppositely disposed duplicative separable conduit sections having ends of unequal width, interfitting means provided on the adjoining longitudinal edges of said sections, a-plurality of separate conduit members disposed in registration with the wider ends of' said sections and means for preventing separation of said sections and connecting said conduits thereto, said means comprising a plurality of bars each of which is formed from a pair of strips joined along the longitudinal axes thereof, the side edges of said strips being spaced to provide a groove at each longitudinal edge of said bar, said grooves being formed-forthe reception of edges of said sections and said conduit members, means in said grooves for engaging the edges positioned therein to prevent the accidental release thereof, and cooperative means provided on said bars for detachably connecting the ends thereof to form an endless collar, said collar preventing separation of said duplicative sections.
9. In a sheet metal duct system, a pair of oppositely disposed duplicative separable conduit sections having ends of unequal width, interfitting means provided on the adjoining longitudinal edges of said sections, a plurality of separate conduit members positioned with their inlet ends in side by side relation and disposed in registration with the Wider ends of said sections, U-shaped strip means engaging the adjacent forward edges of said conduit members, and means for preventing separation of said sections and connecting said conduits thereto, said means comprising a plurality of bars each of which is formed from a pair of strips joined along the longitudinal axes thereof, the side edges of said strips being spaced to provide a groove at each longitudinal edge of said bar, said grooves being formed for the reception of edges of said sections and said conduit members, means in said grooves for engaging the edges positioned therein to prevent the accidental release thereof, and cooperative means provided on said bars for detachably connecting the ends thereof to form an endless collar, said collar preventing separation of said duplicative sections.
1 WILLIAM S. SOMERS.