Nov. 26, 1968 R. HULL. ET AL 3,412,928 
DUAL PASSAGE FAN Filed Aug. 26, 1966 2 Sheets-Sheet l I s RICHARD LL BILLY L' BRISTOL BYCHARLEZ L'.HINTERBERGER ATTORNEYS Nov. :26, 1968 H ET AL 3,412,928 
DUAL PASSAGE FAN Filed Aug. 26, 1966 2 Sheets-Sheet 2 INVENTORS L2 I ICH RD L. u L 
 fiakzasishaiaw ATTi RNEY United States Patent 3,412,928 DUAL PASSAGE FAN Richard L. Hull, Davenport, Iowa, Billy L. Bristol, Silvrs, 
Ill., and Charles L. Hinterberger, Bettendorf, Iowa, assigners to Arnetelr, Inc., New York, N.Y., a corporation of Delaware Filed Aug. 26, 1966, Ser. No. 575,317 3 Claims. (Cl. 230-117) ABSTRACT OF THE DISCLOSURE A split tubular fan casing for housing a motor and shaft and one or two fan wheels, wherein the casing includes a half-barrel section and mating half-barrel and half-conical end sections connected thereto. 
 The present invention relates to a fan casing and more particularly to a fabricated tubular fan casing formed from a reinforced plastic. 
 As is known in the art, the tubular fan casing or split duct fan is provided with a walled aperture therethrough with the fan motor being mounted in the aperture. The fan wheels are mounted at either or both ends of the tubular casing to move the gases through the casing on either side of the aperture. This form of fan casing is particularly adapted to prevent the deterioration of a fan motor when destructive or corrosive fumes or fluids are being moved through the fan casing. 
 When a two-stage fan unit is used, i.e., the fan wheels are located at both ends of the fan casing, it is generally necessary to have a different shaped fan casing than when only single-stage operation is desired. This increases the inventory of fan casings required and also the cost for making fan casings for either oneor two-stage operation. Further, some fluids being passed through the fan casing are so corrosive that the fan casing becomes damaged in a short time and must be replaced. 
 It is, therefore, an object of the present invention to provide a tubular fan casing which can be readily fabricated from standardized components for either oneor two-stage operation. 
 It is another object of the invention to provide a fabricated tubular fan casing made of a reinforced plastic. 
 According to the present invention, one component of the fan casing is a half-barrel section which is a half of the fan casing divided longitudinally. For one-stage operation, a half conical end portion is secured to the corresponding end portion of the half-barrel section to form the end of the casing in which the fan wheel is to be mounted. The remainder of the casing is formed by a portion of a half-barrel section which is attached to the half conical end portion and the half-barrel section. A motor casing is formed and mounted within the fan casing so as to be 90 to the longitudinal axis of the fan casing and to span the entire fan casing. 
 The motor casing is provided with a slot or opening on one or both ends to permit access to the motor and to facilitate removal of the motor from the motor casing. The slot or slots are provided with a cover which is fastened in place when the fan is in operation. 
 The mating surfaces of the half-barrel section, half conical end portion and portion of a half-barrel section are provided with flanges so that these components may be either bolted or bonded together. 
 When two-stage operation is desired, a pair of half conical end portions is attached to the corresponding end portions of a half-barrel section. A pair of center panels is then attached between the half conical end portions and to the half-barrel section to complete the fan casing. 
The components of the fan casing, as described above, 
 3,412,928 Patented Nov. 26, 1968 are molded from a reinforced plastic; in assembly the components are then bonded or bolted together. 
 These and other objects, features and advantages of the invention will become apparent from the following detailed description and accompanying drawings which are merely exemplary. 
In the drawings: 
 FIG. 1 is a side elevational view of the fan casing according to the present invention, with a portion of the casing wall removed; 
 FIG. 2 is a view similar to that of FIG. 1, but with the casing rotated degrees; 
 FIG. 3 is an exploded perspective view of the fan casing of FIGS. 1 and 2; 
 FIG. 4 is a view similar to FIG. 1, but of a fan casing fabricated for two-stage operation; 
 FIG. 5 is a perspective view of the center panels employed in the fan casing of FIG. 4; and 
 FIG. 6 is an overall perspective view of the motor casing employed in the two-stage fan casing of FIG. 4. 
 As may be seen in FIG. 1, the fan casing is indicated generally at 10, and includes inlet end 11 and outlet end 12. The fluid drawn into the casing passes through passages 13 and 14, and then converges at the outlet 12. 
 The fan casing comprises the half-barrel section 15 having end flanges 16 and 17 and longitudinal flanges 18 and 19. The half-barrel section 15 has conical end portions at 20 and 21. Attached to one end portion of half-barrel section 27 is a half conical end section 22 having  end flanges  23 and 24 and longitudinal flanges 25. The end flange 24 has an arcuate portion 26 therein. 
 The remainder of the fan casing comprises a portion of the half-barrel section 27 which has end portion 28 with end flanges 29 and 30. End flanges 30 are provided on the other end of the portion 27, together with  longitudinal flanges  31 and 32. 
 The longitudinal slot 33 is formed in the portion 27 and registers with the arcuate portion 26. A walled aperture, or motor casing 34, is inserted into the sot 33 and extends through the fan casing. A tubular extension 35 extends from one side of the motor casing 34. A motor indicated at 36 is then mounted on a standard motor plate 37 within the motor casing, as shown in FIG. 1. The drive shaft of the motor indicated at 38 extends upwardly through the extension 35 and has a fan wheel 39 mounted on its end. The fan wheel 39 is mounted within that end of the fan casing which is formed by the half conical end portion. 
 For two-stage operation, i.e., with fan wheels at both ends of the fan casing, the fan casing is fabricated as illustrated in FIGS. 4 through 6. Similar to that described above, the two-stage fan casing is formed of the half-barrel section 15, to which is attached the half conical end portion 22, and a second conical end portion 40, which is similar to the end portion 22, is attached to the other end portion 21 of the half-barrel section 15. The second half conical end portion 40 similarly has  end flanges  41 and 42 and  longitudinal flanges  43 and 44. An arcuate portion 45 is also formed in the end flange 42. 
 Two  center panels  46 and 47 are then secured to the half-barrel section 15 between the half  conical end portions  22 and 40. The center panels similarly have   end flanges   48, 49 and 50, 51, together with  longitudinal flanges  52 and 53. The  adjoining edges  54 and 55 of the center panels register with the  arcuate portions  26 and 45 to define a longitudinally extending slot 56. 
 As shown in FIG. 6, a motor casing 57, having opposed  tubular extensions  58 and 59, is then mounted within the slot 56 and extends across the fan casing. 
 For two-stage operation, the motor 36 has its drive shaft 38 extending from both ends, with a second fan wheel 60 being mounted on the lower end. 
 As may be seen in FIG. 3, the motor casing extension 35 is provided with a slot 61 in which is inserted the drive shaft of the motor. A slot cover plate 62 is bonded to the inner surface of the half conical end portion 22 to project over the slot 61 when the motor casing is assembled within the fan casing. 
 The components of the fan casing, as described above, all molded from a reinforced plastic. Such reinforced plastics include fiberglass in bisphenol-furnarate polyester resin such as shown in US. Patent No. 2,634,251 and sold under the trademark Atlac 382 by Atlas Chemical Industries, Inc. The contacting flanges of the several components may be provided with bolt holes so that the flanges may be secured by bolts, or the flanges may be bonded by the same resin used in molding the fan casing components. 
 In order to fabricate a fan casing for single-stage operation, the following procedure has been devised. A halfbarrel section similar to section 15, is molded with respective end and  longitudinal flanges  16, 17, 18 and 19. A portion of a half-section similar to section 27 is molded with end flanges 29 and 30 and with  longitudinal flanges  31 and 32. The motor casing, or tunnel, is then molded to the sections as illustrated in FIG. 3 to form the tubular motor casing along with the drive shaft slot. The half-barrel section and the portion of the half-barrel section are then bonded together along   flanges   31, 32, 18 and 19 with the motor casing being assembled to register with correspondingly shaped openings in the half-barrel section and in the portion of the half-barrel section as shown in FIGS. land 2. 
 A half conical end section similar to section 22 is molded with  end flanges  23 and 24 and longitudinal flanges 25. This half conical end section is then assembled with removable fasteners, such as nuts and bolts, to the half-barrel section flanges and portion of the half-barrel section flanges, as shown in FIGS. 1 and 2. 
 A slot cover plate 62 is molded and then assembled over the slot in the motor casing, the end of cover plate 62 being bonded to the half conical end section 22. The cover plate is held in position tightly over the slot by a stud and nut which project into the interior of the motor casing. 
 Steel motor plate assembly 37 is then bonded to the interior surface of the motor casing as shown in FIG. 1. 
 A pair of directional vanes is molded and then bonded in position on the outer surface of the motor casing near the exhaust end of the fan casing. 
 All bonding of the several components is accomplished using the same resin and reinforcing material as employed in molding the several components. 
 For fabricating a two-stage fan casing, the procedure is the same, except that half conical end portions are used on both ends of the assembled barrel halves. 
 Thus, it can be seen that the present invention provides a fabricated tubular fan casing which is made from reinforced plastic and which is readily adapted for either oneor two-stage fan operation. 
 It is to be understood that details of construction can be varied without departing from the spirit of the invention, except as defined in the appended claims. 
What is claimed is: 
 1. A fabricated molded tubular fan casing of reinforced plastic particularly adapted for the mounting of a fan therein, and comprising a first molded half-barrel section having conical end portions with flanges on said end portions and along the edges of said section, a second molded half-barrel section of less length than said first half-barrel section, a molded half-conical end portion having flanges on both ends thereof and along its longi' tudinal edges and attached to said second half-barrel section, the flanges on said barrel sections being attached, there being an arcuate portion in said half-conical end portion at the larger diameter end thereof, a longitudinally extending slot in said second half-barrel section registering with said arcuate portion in said half-conical end portion a molded motor casing arranged within said slot and extending transversely across said fan casing, said motor casing conforming to the contour of said slot and having a smooth outer surface and the inner surface of said fan casing being smooth and streamlined in a longitudinal direction to permit the smooth flow of air through the fan casing and around said motor casing. 
 2. A fabricated tubular fan casing as claimed in claim 1 wherein said second half-barrel section comprises a second half conical end portion having flanges on both ends thereof and along its longitudinal edges and secured to the corresponding end portion of said second halfbarrel section, there being a second arcuate portion in said second half conical end portion at the larger diameter end thereof, and a pair of central panels having flanges on both ends and along the outer longitudinal edges attached to said second half-barrel section and between said half conical end portions along the corresponding flanges, the adjacent edges of said center panels being spaced and registering with said arcuate portion in said half conical end portions to define said longitudinal slot. 
 3. A process for fabricating a fan casing from reinforced plastic, comprising the steps of molding a halfbarrel section and a portion of a half-barrel section having flanges for bolting on the ends and flanges for bonding along the longitudinal edges from a resinous reinforced plastic, bonding together the half-barrel section and the portion of the half-barrel section along their longitudinal flanges with a resin the same as the resin in the halfbarrel section and portion, molding a motor casing from a reinforced plastic and mounting the motor casing transversely within the assembled half-barrel section and portion of a half-barrel section, mounting a half conical end portion having end and longitudinal flanges upon said portion of the half-barrel section, and detachably connecting said half conical end portion flanges to the corresponding flanges of the half-barrel section and portion of a half-barrel section. 
References Cited UNITED STATES PATENTS ROBERT M. WALKER, Primary Examiner.