US 3181778 A
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R. A. MAYNE May 4, 1965 BLOWER WHEEL 2 Sheets-Sheet 1 Filed March 13, 1961 mmvron W4.
R. A. MAYNE May 4, 1965 BLOWER WHEEL 2 Sheets-Sheet 2 Filed March 13, 1961 HR 4 m2 ways United States Patent 3,181,778 BLOWER WHEEL Robert A. Mayne, deceased, late of Oakwood, Ohio, by Ruth D. Mayne, executrix, Oakwood, Ohio (42 W. Forrer Road, Dayton 19, Ohio) Filed Mar. 13, 1961, Ser. No. 95,456 1 Claim. (Cl. 230--134) This invention relates to a blower wheel and more particularly to a center support for a blower wheel and to the method for assembling the center support in the blower wheel, however, the invention is not necessarily so limited.
This application is a eontinuation-in-part of the Robert A. Mayne application Serial No. 836,767, filed August 28, 1959, for Blower Wheel and Method of Making Same, which application has ripened into United States Letters Patent Number 3,055,085.
The blower wheel to which this invention relates is of the type wherein a plurality of parallel elongate blade elements are supported in a cylindrical array. Ordinarily, the cylindrical array of blades is mounted for rotation on a center support or spider. For effective operation, the center support must firmly engage the blades of the blower wheel, such that rotational torque transmitted to the center support will be delivered to the blower wheel without slippage.
A simple and economical technique for establishing the requisite connection between the center support and the blower wheel is described in copending application Serial No. 385,526, filed October 12, 1953, by Robert A. Mayne and Arthur F. Leis, for a Blower Rotor and Method of Making Same, which application has ripened into United States Letters Patent 3,021,591. In this copending application, techniques are described for expanding a center support disc radially outwardly to engage the blades of a blower wheel. Firm engagement between the center support disc and the blades results from a misfit between the center support disc and the blower wheel, such that the blades of the blower wheel are stressed outwardly and remain under tension. This type of construction gives fully acceptable performance in small sizes of blower wheels. In large sizes, however, centrifugal forces become significant, such that the tension forces established by the misfit between the center disc and the blower wheel yield when the blower wheel is rotated, permitting the center disc to slip in the blower wheel. This leads to faulty operation of the blower wheel.
An object of the present invention is to provide an improved blower wheel construction wherein a center support for the blower wheel is positively interlocked with the blades of the blower wheel, such that slippage therebetween is precluded.
Another object of this invention is to provide an improved center support for a blower wheel having a portion which misfits the blower Wheel soas to place blades of the blower wheel under tension and having a portion which positively engages blades of the blower wheel to prevent slippage of the center support within the blower wheel.
Another object of this invention is to provide a new and improved method for assembling a center support within a blower wheel.
Other objects and advantages reside in the construction of parts, the combination thereof, the method of manufacture and the mode of operation, as will become more apparent from the following description.
In the drawings,
FIGURE 1 is a fragmentary plan view of the blower Wheel of this invention.
FIGURE 2 is a fragmentary, sectional view, taken substantially along the line 2-2 of FIGURE 1.
FIGURE 3 is an enlarged, detail view of the area bounded by the arcuate line 3 in FIGURE 2.
FIGURE 4 discloses a fragmentary view of a modification.
FIGURE 5 is a fragmentary cross sectional view, taken substantially on the line 55 of FIGURE 4.
FIGURE 6 discloses a fragmentary view of another modification.
FIGURE 7 is a fragmentary, cross sectional view, taken substantially on the section line 77 of FIGURE 6.
FIGURE 8 discloses the modification shown in FIG- URE 6 after the center support has been locked to the blower blades.
FIGURE 9 is a fragmentary, sectional view, taken substantially on the section line 99 of FIGURE 8.
FIGURE 10 discloses a fragmentary view of another modification drawn to a larger scale than that used in FIGURES 6 to 9.
FIGURE 11 discloses the modification shown in F1"- URE 10 after the blower blades have been locked in position.
FIGURE 12 is a fragmentary, cross sectional view, taken substantially on the section line 1212 of FIG- URE 10.
FIGURE 13 is a fragmentary, cross sectional view, taken substantially on the section line 13-13 of FIG- URE 11.
Referring to the drawings in detail, FIGURE 1 illustrates a blower wheel comprising a plurality of inwardly projecting arcuate blades or louvers 10 supported in spaced parallel positions in a cylindrical array between beaded end ribs 12. As one example, this blower wheel may be constructed from interleaved stamped sheet metal blade sections in the manner disclosed in the Robert A. Mayne application 543,867, filed October 31, 1955, for a Blower Wheel and Method of Making Same, now Patent No. 2,982,468.
The blower wheel is mounted upon a center support or spider 14 which comprises parallel oppositely dished discs 18 and 20 mounted upon a central hub 16. These discs as clearly seen in FIGURES 1 to 3 are unlike or dissimilar. The discs 18 and 20 are provided with annular outwardly projecting flange portions 22 and 24, respectively, which telescope over the hub 16 and are welded or othewise fixedly secured to the hub 16. The discs 18 and 20 are so located on the hub 16 that their outer peripheries are in abutment and'preferably under slight contact pressure. With this construction, the discs 18 and Z0 brace one another to provide a sturdy structure.
A plurality of arcuate hooks 26 are formed in the outer periphery of the disc 18. One hook 26 is formed for each blade 10 in the blower wheel. As best seen in FIGURE 3, each of the blades 10 is provided with a circular aperture 28 for receipt of a hook 26. To position the hooks 26 in the apertures 28, the center support 14 is slid axially into the blower wheel with the hooks 26 located midway between the blades 10. When the hooks 26 are aligned with the apertures 28, the center support 14 is rotated in the clockwise direction, as viewed in FIG- URE 1, to project the books 26 into the apertures 28. Clearance for movement of the hooks 26 through the blades 10 is afforded by arcuate cut-away portions 30 formed in the disc 18 under the hooks 26. The innermost margins of the blades 16 project into these cutaway portions.
With the construction thus far described, the center support 14 may be loosely interlocked with the blades 10 of the blower wheel, but will easily separate therefrom upon application of a counterclockwise bias thereto. The disc 29 is utilized to take up this looseness and positively interlock the arcuate hooks 26 with the blades 10. The disc 26 has a circular outer periphery, the normal di- Patented May 4, 1965 ameter of which is reduced through the formation of an annular arched protuberance 32 in the disc near its outer periphery. The diameter of the disc 2% after formation of the protuberance 32 is such that this disc will fit loosely in the blower wheel with its outer periphery just making contact with the innermost margins of the blades 10. After the center support 14 has been positioned in the blower wheel with the arcuate hooks 26 on the disc 13 projected into the apertures 28 in the blades 10, the protuberance 32 is pressed out of the disc 20. In this operation, the outer marginal portions of the discs 18 and 29 are pressed together, the protuberance 32 collapsing under the pressure applied.
Collapse of the protuberance 32 in the disc 20 necessarily results in an increase in the diameter of the disc 20. As the disc 20 increases in diameter, the blades 1t) are forced radially outwardly, bringing the innermost boundary of the apertures 28 into compressive engagement with the arcuate underside or bight 27 of the hooks 26. This action positively interlocks the blades with the hooks 26. Thus, the bight in each hook is so formed that the end of the hook turns radially inwardly. When the disc is expanded to force the blades it) outwardly into the bight 27, the inwardly turned ends of the hooks 26 become effective to trap the blades 10 in the hooks 26.
After the protuberance 32 has been pressed out of the disc 20, the assembly of the center support within the blower wheel is complete. Thus, only two operations are required to positively interlock the center support with the blower wheel. First, the central support is slid axially into the blower wheel and rotated in a clockwise direction, as viewed in FIGURE 1, then the protuberance 32 is pressed out to complete the assembly. In regard to this assembly, it may be said that the preexpanded disc 20 functions to maintain a normally snug contact between the center support and the blades 19, while the hooks 26 on the disc 18 function to secure the blades 10 against separation from the disc 243 under the strain of the centrifugal forces to which they are subjected. The portion of each blade between the expanded disc and the hook of the other disc is positively clamped in position.
In the modification disclosed in FIGURES 4 and 5,
a single center disc 46 has been used that is provided with a radially disposed incision 42, the width of which has been greatly eXaggerated for the purpose of clarity. The center disc is provided with a hook-shaped portion 44 entering an aperture 28 in the blade 19. The portion of the disc located on the side of the incision 42 opposite the hook-shaped portion is deflected into a V-shaped portion 50 into the shape shown in dot-dash lines in FIG- URE 5. By straightening out this portion 59 into a substantially radial position, as illustrated by 56a, the outer margin 52 of the portion 50 abuts the inner margin of the blade 10, so as to clamp the portion of the blade located between the aperture 28 and the inner margin between the hook-shaped portion 44 and the outer margin 52 of the portion 50.
By deforming the portion of the disc adjacent the incision 42 on the side opposite the hook-shaped portions 44, the margins of the disc underlying the hook-shaped portions are shrunk to permit the insertion of the hookshaped portions 44 into the apertures 28 of the blades 19 and then, upon straightening the deformed portions, the margins 52 of the disc underlying the hook-shaped portions 44 are extended into contact with the inner margins of the blades 16.
In the modification shown in FIGURES 6 to 9, a single center disc 60 is again used in supporting the blades 62 of a blower wheel. In this modification, a plurality of tongues 64 underlie the inner margins of the blades and are formed by radial incisions 66 and 68. Each of the tongues 64 is provided with concavo-convex ribs 69. The ribs 69 retract the outer margins of the tongues 64. There is one tongue mounted inwardly from each blade 62.
Hook-shaped portions 70 extend radially between the tongues 64. Each hook-shaped portion 7 0 terminates in a hook 72 that is projected through a slot 74 in the adjacent blade 62. After the hooks 72 have been projected through the slots 74, the ribs 69 are squashed or flattened to expand the tongues radially outwardly, so as to be seated in a small notch 76 in the inner margin of each blade. As the ribs are flattened, the tongues 64 clamp the margins of the blades against the hooks 72 to firmly hold the blades in position. The stem 73 of each book adjacent the blade fits the adjacent portion of the blades to brace the same. Furthermore, the outer edge of the tongues 64 are bevelled or inclined, so as to wedge the inner margin of the blades against the stems 73.
In the modification shown in FIGURES 10 to 13 inclusive, a center disc 80 is provided with a concavoconvex bead or rib 82 located adjacent the margin thereof and extending throughout the entire periphery of the disc. The disc is provided with outwardly directed hooks 84, each having a radially extending neck portion 86. The hooks are adapted to project through slots 88 in blades 90. The margins 92, extending between the adjacent hooks 84 of the center disc, are adapted to be pushed into notches 94 in the inner margins of the blades upon the bead 82 being flattened.
When the head 82 is flattened between die members and 102, as shown in phantom, the hooks 84 are restrained from outward radial movement. This func tion is accomplished by stops 104 integral with die member 100. In order to take up the radial expansion produced by flattening of the head 82, a forming tool 166 engages the neck portion 86 of each hook 84, simultaneously as the head 82 is flattened, to form a head or rib 108 therein, as clearly shown in FIGURE 13. This tool 106 is supported with a stiff spring 107 that permits the tool 106 to yield and thereby compensate for shortness in the neck portion 86. This prevents subjecting the metal in the neck portion to unnecessary stretching while at the same time taking up slack in the neck portion.
Upon flattening of the bead 82, the inner margins of the blades are forced outwardly by the expanded margin of the center disc. As a consequence, the lower portion 110 of each blade is clamped between the associated hook 84 and the margin 92 of the disc. In this modification, the bead 82 is flattened or eliminated simultaneously with the formation of a rib 108. In effect, the bead 82 is transferred from the main body of the center disc to the neck portions 86 in the hooks 84.
It will occur to those skilled in the art that numerous variations may be made in the design of this center support structure, without departing from the scope and spirit of the present invention. As one example, it is an obvious expedient to engage only a portion of the blades 10 with the center support where the structural requirements for the blower wheel admit of such construction.
Although the preferred embodiment of the device has been described, it will be understood that within the purview of this invention various changes may be made in the form, details, proportion and arrangement of parts, the combination thereof and mode of operation, which generally stated consist in a device capable of carrying out the objects set forth, as disclosed and defined in the appended claim.
The invention having been thus described, it is claimed:
In a blower wheel, the combination including a hollow cylindrical body member having a plurality of spaced axially disposed blades, said blades each having an aperture, a center support comprising a hub, means for attaching the blades in fixed relation to the hub, said means including two unlike discs, one of said discs being fixedly mounted on said hub, said one disc having a generally circular outer margin engageable with the innermost margin of said blades, the second of said disc being fixedly mounted on said hub adjacent said first disc, said second disc having interlock hook portions on the outer periphery thereof projecting radially outwardly beyond the margin of said first disc interengageable with the apertures in said blades, the interlocked hook portions of the second disc and the outer margin of the first disc positively clamping the intermediate portions of the blades.
References Cited by the Examiner UNITED STATES PATENTS 6 Osborne. Wilken. Zink. Austin et a1. Merz. Mayne et al 29156.8 Mayne 29-1568 Mayne et a1.
FOREIGN PATENTS Italy.
JOSEPH H. BRANSON, JR., Primary Exqminer.
LAURENCE V. EFNER, Examiner.