US598216A - Xventilating w wheel or fan - Google Patents

Description

(No Model.) 2 Sfi eet$Sheet 2.

W. H. A. DAVIDSON. VENTILATING WHEEL 0 FAN.

No. 598,216 Patented Feb. 1,1898.

' 1 mn'uulllullll mlmlllunin? FIE-m Nrrnrans I WILLIAM H. A. DAVIDSON, OF CAMBRIDGE, MASSACHUSETTS.

VENTILATiNG WHEEL OR FAN.

SPECIFICATION forming part of Letters Ilatent No. 598,216, dated February 1, 1898.

Application filed July 1, 1895. Serial No. 554,624. (No model.) i

To all whom it may concern.-

Be it known that 1, WILLIAM H. A. DAVID- SON, a citizen of the United States, and a resi- I-Ieretofore ventilating wheels or fans have been constructed with blades of divers shapes set radially and at an angle to and across the axis of the shaft which constituted their cen 'ter of rotation. In such fans only the forward or cutting edge of the blade was effective to gather in the air, while the configuration of the blade-surface tended to disperse the volume of air passed through the fan in directions at various angles to the axis of rotation of the fan, and where the air was to be forced through ducts or confined channels placed in the rear of the fan such diverging currents tended to create friction and resistance to the effective work of the fan.

I have in practical tests of my invention segment of a prolate spheroid when arranged in the fan as last above stated are better and more efficiently adapted to concentrate and deliver the current of air through the fan in right lines, or nearly so, parallel with the axis of the fan, and with a minimum of frictional resistance where the air is to be forced through ducts.

I have secured the best results by constructing the blade in the form of a segment of a prolate spheroid or in the form of a spoonbowl, from which its extreme ends have been cut oif in such manner as to provide a blade with an inner concave face and an outer convex face and by arranging such blades in the wheel or fan in manner following: I first socure upon the shaft or hub spokes, each of which projects from said shaft with its longitudinal axis at the point of junction with the shaft or hub, eccentric to the axis of the latter; Upon each said spoke I secure, preferably adj ustably, an arm which projects from the rear side of said spoke with reference to the direction of rotation. Upon said rearward-projecting arms I secure blades of the character above described, with their surfaces at approximately right angles tothe longitudinal axis of said spokes and angularly inclined to the vertical plane of the axis of rotation. Said blades are arranged to extend forward of the spokes and are set with their cutting edges nearest the periphery of the wheel and their delivery edges nearest the center of the wheel.

The fan is mounted in a frame or bearings and driven in the ordinary way. It may be used in connection with an air-duct or not,

as may be desired.

Within considerable limits the outline of the edges of the blade may be varied, (I have shown two variations,) provided the essential curvatures, such as are found in a spoon-bowl,

are retained.

In the accompanying drawings, illustrating myinvention, Figure 1 is a front elevation of a fan embodying my invention. Fig. 2 is a side elevation of the same. Fig. 3 is a rear View of the same,looking in the direction of the arrows from line 00 w of Fig. 2.. Figs. 4E and 9 show the mode of attaching and securing the blade, a portion of the blade being broken away and the arm and clamping-nut being shown in section. Fig. 5 shows a plan, a side, and a sectional view of the split clamping-nut. Figs. 6, 7, and S are respectively front, side, and rear views, differing from Figs. 1, 2, and 3 only in the shape of the outer edge of the blades. Fig. 10 is a section on line 2 z of Fig. 9.

Similar letters of reference indicate like parts where they occur in the drawings.

A represents the blade, which may, as shown in Figs. 1, 2, 3, and 4, have the spoon-shaped outline, or, as shown in Figs. 6, 7, 8, and 9, while still preserving the curvatures of a spoon-bowl, may at the same time have its opposite sides or edges more nearly parallel, and in either case is provided with a stem or shank or secured upon an arm a, the lower end of which is threaded and adapted to be engaged by an internally-threaded split clamp-nut n, provided with rectangular tapered sides adapted to fit into the correspondingly-tapered rectangular orifice in the spoke b and to be drawn thereinto bindingly by the action of the check-nut against the under side of said spoke b, to rigidly secure the blade in position with its surfaces at approximately forty-five degrees to and at the longitudinal axis of the arm and angularly inclined to the vertical plane of the axis of the fan. The spokes b are located upon the side of the hub or shaft of a wheel or fan eccentrically to the axis of the same and extend outward in a radial direction from said hub or shaft. The spokes b may, if desired, form an integral part of the hub or shaft.

. The shaft 3 may be mounted on bearings or in a frame in the usual way and operated in the ordinary manner. The blade may be adj usted at any desired angle to the axis of the shaft and thereby adapted to varying conditions and exigencies of work.

I claim as my invention and desire to secure by Letters Patent- 1. The combination with the fan-shaft of spokes projecting therefrom, substantially spoon-shaped. blades secured to arms projecting from the rear side of said spokes with reference to the direction of rotation, with their surfaces at approximately right angles to the longitudinal axis of the spokes and inclined to the vertical plane of the axis of rotation, the said blades extending forward of the spokes and so set that their cutting edges are nearest the periphery and their delivery edges nearest the center of the wheel.

2. In a ventilating wheel or fan spokes located on the side of the shaft of rotation and projecting in a radial direction therefrom with the longitudinal axis of said spokes at their junction with said shaft eccentric to the axis of the latter, arms adjustably secured upon said spokes and projecting from the rear side thereof with reference to the direction of rotation, and substantially spoon-shaped blades secured to said arms and extending forward of said spokes with their surfaces at approximately right angles to the longitudinal axis of said spokes and angularly inclined to the vertical plane of the axis of rotation and so set that their cutting edges are nearest the periphery and their delivery edges nearest the center of the wheel.

3. In a ventilating wheel or fan spokes I) each located upon the side of the shaft of rotation and projecting in a radial direction therefrom with their longitudinal axis at the point of junction with said shaft eccentric to the axis of the latter, combined with blades arranged upon the rear side of said spokes with reference to the direction of rotation,

with their surfaces at approximately right angles to the longitudinal axis of said spokes and inclined to the vertical plane of the axis of rotation, the said blades extending forward of the spokes and so set that their cutting edges are nearest the periphery and their delivery edgesnearest the center of the wheel.

4. The combination with a shaft and hub, of spokes b secured on the side of said hub and projecting in a radial direction therefrom, with the longitudinal axis of said spokes at the point of union with the hub eccentric to the axis of the latter, and blades A adj ustably secured and centrally supported upon the rear side of said spokes with reference to the direction of rotation with their surfaces at approximately right angles to the longitudinal axis of the spokes and inclined to the vertical plane of the axis of rotation, the said blades extending forward of the spokes and so set that their cutting edges are nearest the periphery and their delivery edges nearest the center of the wheel.

5. In a ventilating wheel or fan, the blades A provided with a threaded stem or shank, the annular split clamping-nut c and checknut n, all combined with each other and with the spokes I) provided with a rectangulartapered orifice, and arranged and adapted to serve as specified.

In testimony whereof I have hereunto set my hand, in presence of two witnesses, this 29th day of June, 1895.

WILLIAM H. A. DAVIDSON.

Witnesses:

HENRY MARSH, J11, E. A. GOLDING.

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