US 3485443 A
Description (OCR text may contain errors)
FAN SCROLL Filed Dec. 12, 1968 INVENTOR. WALTE R EAR HART United States Patent O 3,485,443 FAN SCROLL Walter Earhart, La Crosse, Wis., assgnor to The Trane Company, La Crosse, Wis., a corporation of Wisconsin Filed Dec. 12, 1968, Ser. No. 783,367 Int. Cl. F0411 39/12; F04d 17/08, 29/42 U.S. Cl. 230-233 8 Claims ABSTRACT OF THE DISCLOSURE A fan scroll for unit ventilators and similar apparatus combines the function of sound attenuation with structural support through the use of a self-supporting, substantially rigid, sound attenuating material, such as resin-bonded glass fibers.
BACKGROUND OF THE INVENTION Field of the invention This invention relates to fluid moving fans, and more particularly, to a novel fan scroll assembly for use with centrifugal and cross-flow fans.
Description of the prior art In room heating, Ventilating, and cooling equipment installed in classrooms, hospitals, apartment buildings and similar structures, the use of centrifugal or cross-flow fans is common to circulate the air throughout the room being conditioned. Since air movement using this type of fan creates undesirable sound levels, it has been the practice to employ some type of sound deadening material in the fan structures. This sound deadening material or insulation is normally placed around or combined with the fan scroll which surrounds the fan rotor. In the past, this sound deadening material has not been associated with SUMMARY OF THE INVENTION The instant invention provides a fan scroll assembly comprising a scroll portion composed of a self-supporting, substantially rigid, sound attenuating material, the scroll portion being the major structural member of the scroll assembly; the fan assembly further comprises a pair of end plates having intake ports therein and fastening means for securing the end plates against opposing sides of the scroll. The scroll is preferably made from glass fibers bonded together by a suitable resin and contains ra fluid imperforate layer, for example, a sheet of polyethylene which is located intermediate the inner and outer surfaces of the fan scroll.
BRIEF DESCRIPTION OF THE DRAWINGS FIGURE l is an exploded perspective view of the fan scroll assembly of the instant invention.
FIGURE 2 is a vertical cross sectional view of the fan scroll.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGURE l, fan scroll 1 is molded from a self-supporting, substantially rigid, sound attenuating ice material. End plates 2 and 3 are provided which fit against the side portions of fan scroll 1. Flanges 4 fit around the outer edge of the fan scroll. Fastening rods 5 are inserted through eyelets 6 on each of the end plates 2 and 3. The end plates are secured tightly against the side portions of fan scroll 1 by inserting clips 7 onto the portions of rods 5 which extend through eyelets 6 on end plate 2. Clips 7 are of the spring fastening type; however, threads can be provided on rods 5, and screw type fasteners can be used in place of the spring clips 7.
The end plates 2 and 3 can be stamped steel stock, molded rigid polymeric material, or can be manufactured or molded from the same material of which the fan scroll 1 is composed. Flanges 8 and 9 are provided on end plates 2 and 3 to secure the fan scroll assembly to an installation surface; for example, the fan board of a unit ventilator. Air inlet orifices 10 and 11 are provided in each of the end plates 2 and 3. A rotor assembly connected to a suitable driving means (not shown) can be placed inside scroll 1 when the scroll assembly is installed.
Of course, the scroll shape depicted in FIGURE 1 is not the only configuration in which the instant invention can be utilized. Suitable modifications can be made to the scroll and end plates to enable it to be used in a cross-flow fan or other air handling equipment which requires a housing.
In reference to FIGURE 2, a cross sectional view of the fan scroll is illustrated. In the preferred embodiment the fan scroll is molded from glass fibers, shown as 15, which are bound together by a suitable resin, shown as 16. To reduce friction and also to eliminate airflow through the insulating material, a neoprene coating is applied to surfaces 17 and 18, although for effective operation of the instant invention neither is necessary. As the fan scroll is being molded, a sheet of polymeric material 19 is positioned between the inner and outer surfaces of the scroll. In the preferred embodiment a polyethylene sheet is employed.
Other rigid, self-supporting insulating materials which can be used instead of resin-bonded glass fibers are foamed polyethylene or polystyrene. Requisite-s of the scroll material are that it be able to withstand the temperatures associated with its application in unit ventilators or similar equipment and that it be sufficiently rigid to form the major structural member of the fan scroll assembly.
Other coatings for surfaces 17 and 18 include polychloroprenes, vinyl, polyethylene, paper, oil, or other material which -would inhibit the fiow of fluid through the fan scroll. The sheet-like layer 19 inside the fan scroll can similarly be made from paper, polychloroprene (for example, poly-z-chlorobutadiene), vinyl, foil, or other materials able to withstand the molding temperatures Iand the temperatures of the particular scroll application. Suitable binder resins for the glass fibers are polyesters, epoxys, for example, an amine cured Bisphenol-A-epichlorohydrin, silicone resins, polyamides, acrylics, polyvinylacetate, and polystyrenes, for example, a polymethylstyrene. The materials set forth above are not intended to be exhaustive of those which can be utilized in the instant invention. They are merely intended to be representative.
The utility of this invention is apparent from the foregoing disclosure. Therefore, what is claimed is:
1. A fan scroll assembly comprising `a scroll portion composed of a self-supporting, substantially rigid, sound attenuating material, said scroll portion being the major structural member of said scroll assembly, said fan assembly further comprising a pair of end plates having intake ports therein, and fastening means for securing said end plates against opposing sides of said scroll.
2. The fan scroll assembly of claim 1 wherein the said scroll includes a uid imperforate layer.
3. The fan scroll assembly of claim 2 wherein said fluid imperforate layer comprises a polymeric sheet contained -as an integral part of said scroll and located intermediate the inner and outer surfaces of said scroll.
4. The fan scroll assembly of claim 2 wherein said fluid imperforate layer comprises a resinous coating on at least one of the inner 4and outer surfaces of said scroll.
5. The fan scroll assembly of claim 2 wherein the scroll consists essentially of glass fibers bound together in a substantially rigid form with a resinous binder.
6. The fan scroll assembly of claims 2 and 5 wherein said end plates include bracket means for mounting said fan scroll assembly.
7. The fan scroll assembly of claim 2 wherein the scroll consists essentially of a foamed polymeric material.
8. The fan scroll assembly of claim 3 wherein said scroll contains an additional uid imperforate layer comprising a resinous coating 0n at least one of the 4inner and outer surfaces of said scroll.
References Cited UNITED STATES PATENTS 2,465,625 3/1949 Ave 23o-127 3,018,736 1/1962 c1ay 10s-114 XR 0 3,395,775 8/1968 smith 23o-233 XR ROBERT M. WALKER, Primary Examiner U.S. Cl. X.R.