US2750103A - Blower wheel - Google Patents

Description

June 12, 1956 H. D. FRANKE 2,750,103

BLOWER WHEEL.

Filed April 27, 1953 ll! VEHTOR Harry D. Wanke,

B: M Q AH-orne United States Patent O BLOWER WHEEL Harry D. Franke, Columbus, Ind., assignor to Vernco Corporation, Columbus, Ind., a corporation of Indiana Application April 27, 1953, Serial No. 351,429

4 Claims. (Cl. 230-134) This invention relates to a blower wheel or what may be termed a fan, and the invention resides particularly in the unique structure of forming the fan in the absence of having to use cast parts, having to weld any parts, or do any brazing whatsoever.

Briefly, the invention resides in forming a length of tubing around which are positioned a plurality of pairs of fan blades joined together by webs in each pair, and having flanges turned from the webs around and into the tube with a core pressed inwardly to carry those flanges compressively inside of the tube to fix the fan blades in the desired circumferential location around the tube.

One of the advantages of the invention, in addition to the great saving in cost of production, is the lending of the structure to an extremely light weight since the entire structure may be made out of one of the light metals, such as aluminum, aluminum alloys, magnesium, or magnesium alloys, and the like. It is believed that these and many other advantages of the invention will become apparent to those versed in the art in the following description of one particular form of the invention as illustrated in the accompany drawing, in which Fig. 1 is a view in rear elevation of a structure embodying the invention;

Fig. 2 is a central diametrical section on the line 2-2 in Fig. 1;

Fig. 3 is a fragmentary section on the same line, showing a modified form of hub; and

Fig. 4 is a view in plan of a blank from which a unit of fan blades is formed.

A length of tubing 10 is selected from the desired metal, such for example as an aluminum alloy which is extremely hard and elastic. The internal diameter of this length of tube 10 will vary depending upon the size of the wheel to be formed, and correspondingly with the size of the hub used.

Around this tube 10, on the outside thereof, there is mounted a plurality of fan blades 11.

Referring to Fig. 4, the metal selected from which the blades 11 are to be made, such as aluminum which may be soft or any alloy or other metal as may be desired, is blanked out to have a generally rectangular central section defined by the lines AB, BC, CD, and DA. This rectangular area extends from the blank generally designated by the numeral 12, to one side thereof, herein shown as the right side, from a straight edge EH, the area extending from that line EH by the lengths of the lines PB and GC.

From the outer transverse edge IE, the left edge is extended from I to K, and then diagonally inwardly and toward the line AB to a point such as L, and likewise from the lower or other transverse edge MH, the left band edge is carried inwardly to a point such as N and then diagonally to the point at the line DC. This leaves a rectangular portion ALOD of the central panel extending between the diagonal lines KL and NO, this rectangular portion being substantially equal in area to the other rectangular portion FBCG extending from the edge EH.

Patented June 12, 1956 With the blank thus formed, the portion JKLFE is formed into one blade 11 with a curvature such as is indicated in Fig. l, and the portion HMNOG is formed into a blade 1112 with the same curvature as indicated in Fig. 1. Thus the two blades 11 and 11a are formed integrally with the intervening web LFGO therebetween, and this web is formed arcuately to have the same radius of curvature between the blades 11 and 11a as the curvature of the outside of the tube 10. The blades 11 and 11a extend from that web IFGO along the dash lines LF and 0G. The tabs or flanges ALOD and FBCG are bent substantially at right angles to the web, the bend lines being along the lines L0 and FG. I

With the blank 12 thus formed, it is placed on the outside of the tube 10, and subsequent blank 12 are positioned around the outside of the tube 10, depending upon the number of fan blades desired. In the form herein shown, three of these blanks 12 are employed so as to give six blades 11. By any suitable fixture means (not shown), these pairs of blades 11-11a are positioned in equal circumferential spacing around the tube 10, and there held. Then a central plug or core 13 is forced inwardly of the tube 10 to carry the flanges or tabs FBCG, designated by the numeral 14, inwardly of the tube 13 to cause the tab to be forced around the end of thetube and back inside thereof with the plug 13 compressively urging the end portion 14 of the tab at least at its side edges against the wall of the tube with considerable pressure.

The plug 13 is selected, when there are to be six blades assembled on the tube 10, to have three flat sides 15, 16, and 17. These sides 15, 16, and 17 are equally spaced around the core 13, and may be had by employing a length of hexagonal bar stock. In any event, the size of the plug 13 is such that it has to be forced into the tube 10 to carry the tabs 14 inwardly thereof and hold them with considerable pressure against the inner face or of the tube 10. Since the tube 10 has a high degree of tensile strength, and is elastic in nature, that pressure will be maintained without unduly distorting the tube 10.

As indicated in Fig. 2, the plug 13 is inserted from one end, herein shown as from the right side, and extends slightly more than halfway through the length of the tube 10. A second plug 18 is forced into the tube 10 from the left hand end to carry the tabs 19, ALOD, around and into the tube and into compressive engagement with the inside thereof, this plug 18 likewise being identical to the contour of the plug 13 so as to maintain those tabs 19 in position. Both the plugs 13 and 18 are thus positioned within the tube with a pressed fit, and the blades 11 are thus fixed circumferentially around the tube 10, and no further anchoring means is required.

Referring to Fig. 3, a modified form of hub 24 is employed wherein the hub 24 is a one piece hub, and preferably has a round nose 25 extending from the tube 10 on that side toward which air will be flowing to be delivered outwardly from the blades 11. In like manner, this plug 24 is forced into the tube 10 to hold the tabs 14 and 19 compressively against the inner side of the tube 10 so as to fix the blades in position.

The hub 13 is provided with a central bore 26 to receive a driving shaft (not shown), and there is a tapped hole through the web LFGO designated by the numeral 27, this tapped hole extending on through the tube 10, and in axial alignment with a tapped hole 29 through the plug 13 so that a set screw (not shown) may be screw-threadedly entered through the web 20 and brought to bear against the shaft entered within the bore 26, this means not only engaging the fan assembly with the shaft, but also further aiding in preventing any possibility of cir cumferential movement of the plug 13 and the fan assemblies circumferentially around the tube 10.

It is to be understood that the tabs 14 and 19 are wrapped very tightly around the opposite ends of the tube 10-when-the endportionsthereof-are'carried inside of the tube so that there is a tight engagement of the web 20 against the outside of the tube 10, .a tight engagement across 'the ends of the tube "1'0, and aftight engagement against the inside of-the'tube '10.

Obviously, the shapes of theblades lljmaybe'variedin accordance with the requirements of the blower'wheel, andthey 'are not necessarily limited to the shape shown in the accompanying drawing and 'as-illustrated and describedin-referenceto'the blank-in Fig. 4. The invention doesnotreside'in the exact-shapes-oftheblades '11 but in themounting of the blades for driving operation.

Therefore, while I have shown the invention in the one particular form'and described it-moreor lessminutely in reference-to the accompanyingdrawing, '-I do-notintencl to be limited to that precise formbeyond the limitations which may be imposed-"by the following claims.

"-I-claim:

-1. A blower wheel assembly'cornprising a tubular hub member open at eachend; a pair of fan blades having inner, hub directed ends; a web integral with and interconnecting said-blades at saidinner ends and'lying freely longitudinally along the outside of said hub member; a tab at eachend of said web extending integrally-therefrom across the end wall thickness-of said hub member and back there within, lying by a length-longitudinally along the inside surface of said hub wall; and aplug-within said hub member of a diameter compressibly urging and retaining said tab lengths against said wall surface, one tab end opposing 'the other 'tab end, said tabs intervening throughout their lengths between said hub surface and said plug, and said plug being longitudinally retained in said plug member solely by said tab compressive engagement.

2. The structure of claim 1 further characterized by said plug being substantially non-elastic transversely, and said tabs being confined to contact vwith said plug to externally longitudinal surfaces thereof.

3. The structure of claim 1 in which said .web is in effect stretched tautly and'longitudina'lly across said member, and the tabs are stretched transversely .across the end of the wall of said hub member and ,pulled inwardly thereof and retained under tension by said plug interengagcment with tabs at both ends of said hub therewithin.

4. The structure of claim 1 in which said plug is in two parts, one part engaging the tabs at one tube end andthe other plug part engaging the tabs at'the opposite Ltube end.

References Cited in the file-0f this patent UNITED STATES PATENTS 489,257 Maris .J,an..-3, 1893 1,325,591 Stecker Dec..2-3, 1919 1,426,954 Brooks Aug. 22, 1922 1,758,062 Replogle May 13, 193.0 2,130,146 McKee .Sept. 13,1938 2,216,747 Klimek Oct. 8, .1940

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