US2585265A

US2585265A - Fan blade structure

Info

Publication number: US2585265A
Authority: US
Inventors: George L Moeller
Original assignee: Knapp Monarch Co
Current assignee: Knapp Monarch Co
Priority date: 1945-04-10
Filing date: 1945-04-10
Publication date: 1952-02-12
Anticipated expiration: 1969-02-12

Description

Feb. 12, 1952 G. MOELLER FAN BLADE STRUCTURE Filed April 10, 1945 I INVENTOR. 61 60 541 Aha/lei:

Patented Feb. 12, 1952 UNITED STATES OFFICE 2,585,255 BLADE STRUCTURE George L. Mueller, St. Louis, Mo., assig nor, by inesne assignments, ie "Knapp-Monarch St. Lbuis, M0., -"a' corporation of Delaware Application April :10, 1945, Serial No. 537,571

2 Claims. (Cl. 170 -1595) 1 My present invention relates to a fan blade strilctureof simple and light construction.

One object of the invention is to providea fan blade structure formed of 'a non-metallic material such as paper base material, or laminated harm to anyone happening to come in contact blade Ill.

with the blade while it is rotating.

Still another object is to provide a fan blade which can be cut from a sheet of thermo-plastic material and then heated and formed to the desired shape to produce pitch for air delivery, or

cut from a semi-cured material which becomes completely cured and takes a set upon the application thereto of pressure and/ or heat.

With these and other objects in view, my invention consists in the construction and arrangement and combination of the various parts thereof whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of a fan blade structure embodyfiig my invention;

Figure 2 is a front elevation thereof showing in dotted lines the original fiat shape of the fan blades;

Figure 3 is a rear view of the structure;

Figure 4 is an enlarged sectional view on the line 44 of Figure 1; and

Figure 5 is a bottom plan view of the hub and center plate of Figure 4 before the fan blades are connected thereto.

0n the accompanying drawings I have used the reference numeral H] to indicate a fan blade. Four of the blades are shown and they are connected together at the center by a disk-like portion l2, the four blades l0 and the portion [2 being all formed of a single sheet of material and in the initially fiat shape shown by dotted lines Illa in Figures 1 and 2.

The disk-like portion I2 is reinforced by a metal plate M of disk-like character formed on a hub [6. The hub 16 is adapted to be secured to a shaft l8 of an electric motor or the like as by a set screw 20. The plate M has a central extension 22 formed with a pair of beads 24 which fit a similarly shaped center hole 26 of the disk-like portion 12 of the tem blades. The disk like 'portion is also provided with perforations 28 through which studs 30 of the plate 14 extend, and for assembly purposes these are riveted as at '32 over a metal disk 3 The central portion I 2 hf the tan blades is thereby confined between th'e disks l4 and 3 1 which suitably reinforce the blades and provide a :good mechanical connection to a shaft for rotating the fan structure.

I lit will be noted thatadjacent the peripheryof the disk It corrugations are formed the material of the fan blades ID for the purpose of reinforcing the blades at the transition point from the hub plate I 4 to the main body of each The method involved in forming the fan structure is as follows: First, the blades l0 and the center disk portion l2 are cut from a single sheet of non-metallic material such as a thermo-plastic or a laminated phenolic plastic to the shape shown by dotted lines in Figures 1 and 2. The blades are then heated in order to make them plastic and while heated they are formed in a press to the proper angle or pitch for air delivery upon rotation, these angles being best shown in Figure 2. The blade structure is then permitted to cool so that the blades set in the shape to which they were formed in the press and retain such shape under ordinary moisture and temperature conditions.

In the case of a blade which is made of semicured material the blade becomes completely cured and takes its set when it is finally formed in the press, the curing resulting from the pressure produced by the press. At the same time, heat may be applied in addition to the pressure to completely cure the material.

After the blades are formed as just described they are assembled relative to the hub 16 in the manner already described to form a completed fan blade structure which can be mounted on a shaft of a fan motor or the like.

The resulting structure is light in weight and thus safer to operate. It is inexpensive to manufacture both from the material and labor standpoint. The material is readily cut in a die and formed in a press after the material is heated to make it plastic. The subsequent operations of assembling the hub and the disk 34 are simple to perform, and balancing the structure may be quickly and conveniently done by trimming off the heavy blades until proper balance is secured.

Some changes may be made in the construction and arrangement of the parts of my fan structure and the steps of the method can be varied without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof.

I claim as my invention:

1. In a fan blade structure, a plurality of blades integral with a central disc portion, said blades and disc portion being of non-metallic material, said blades being shaped to provide pitch for air delivery resulting from rotation of the structure, and a metallic hub for said fan blades having a plate-like portion, said central disc portion of said fan blade structure being connected to said plate-like portion, each blade at its innermost portion adjacent said disc portion being arcuate shaped in radial cross-section, and said inner-most portion having reinforcin corrugations extending radially outward from the periphery of said central disc portion.

2. A fan blade structure comprising a sheet of non-metallic material shaped to provide a plurality of blades connected together by a cupped central disk-like portion, a metallic reinforcing disk therefor, said blades being permanently formed to produce pitch for air delivery resulting from rotation of the structure, and a metallic hub for said structure having a plate-like portion provided with studs extending through said disk-like portion and said reinforcing disk and 5 to the main portion of the blade, said corrugations being entirely opposite the cupped side of the plane of said plate-like portion of said hub. GEORGE L. MOELLER.

1 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,773,349 Bothezat Aug. 19, 1930 2,016,568 Zinser Oct. 8, 1935 2,033,345 Lee Mar. 10, 1936 2,095,162 Wood Oct. 5, 1937 2,100,891 Zinser Nov. 30, 1937 2,202,042 Blount May 28, 1940 2,234,319 Preston Mar. 11, 1941 2,251,887 Larsh Aug. 5, 1941 2,251,888 Leflar Aug. 5, 1941 2,346,552 Brotz Apr. 11, 1944 2,370,652 Frisbie Mar. 6, 1945 2,378,049 Upson June 12, 1945 FOREIGN PATENTS Number Country Date 212,488 Great Britain Mar. 13, 1924