US2337700A - Rotary fan - Google Patents

Description

Dec. 28, 1943. P. WAREHAM ROTARY FAN Filed Aug. 12, 1942 INVENTOR.

Pmcr W 37 Patented Dec. 28, 1943 ROTARY FAN Percy Wareham, Royal Oak, Mich assig-nor of one-half to James M. Toy, Detroit, Mich.

Application August 12, 1942, Serial No. 454,623

6 Claims.

This invention relates to rotary fans, the ob- Ject being to provide a new' and improved fan structure comprising a plate having blades on one side of the plate arcuate in form in cross section and of a half-cone shape from the center toward the periphery and blades on the opposite side of the fan inclined to the plane of rotation and extending at an angle to the plane of the plate and discharging air picked up in revolution into the arcuate blades to discharge peripherally therefrom in the plane of rotation of the fan.

It is further a feature and object of the invention to form the fan of a sheet metal plate and to provide the aforesaid arcuate blades by attaching the same to the plate surface and to form the blades extending outwardly from the opposite sides of the plate by punching the plate to form the angularly disposed blades in such relationship that the angularly disposed blades in revolution of the fan pick up air and discharge the same to the arcuate blades on the opposite side of the fan plate. Thus the arcuate blades discharge not only the air flowing thereinto by reasons of the angularly disposed blades but also air picked up by the arcuate blades in the plane of revolution thereof.

It is also a feature and object of the invention to provide a fan structured formed of comparatively thin sheet metal plate of circular form and the arcuate and angularly disposed blades extending on a tangent from a small circle at the center of revolution to the periphery of the circular plate forming the base or body of the fan.

These and other objects and novel features of the invention are hereinafter more fully described and claimed and the preferred form of construction of a'rotary fan embodying my invention is shown in the accompanying drawing in whicha Fig. 1 is a plan view of the discharge face of the fan.

Fig. 2 is a section of the fan taken on line 2--2 of Fig. l and showing one manner of mounting the fan to an element for rotation thereof.

Fig. 3 is a fragmentary view showing a portion of the plate and the relationship of the arcuate and angularly disposed blades in perspective.

In the preferred form of construction my improved fan comprises a sheet metal plate l of circular form having a central aperture to receive a driving shaft 6 and the angularly disposed blades 3 may be formed by punching the plate I to provide blades of less width at the inner ends than at the peripheral ends as will be understood from Figs. 1 and 3 and providing openings 4 through the plate I. The blades 3 are disposed preferably at an angle of approximately thirty-three and one-third degrees to the plane of the plate and, being of less width at the center than at the periphery, the volume of air picked up per revolution of the blades 3 is greater at the periphery than at the center due to the triangular form of the blades and to the fact that the distance travelled by the outer periphery of the angular blades per unit of time is greater than at the inner end thereof.

The arcuate blades 5 are preferably formed of sheet metal having a fiat base portion So attached to the plate at the rear of the opening 4 in the direction of travel and extending rearwardly therefrom and forwardly curved to form an arcuate portion of the form of a half-cone having its innermost point adjacent the center of the fan plate and providing a blade that is of increased capacity for pickup and delivery of air from the center toward the periphery corresponding in this respect to the capacity of the angularly disposed blades 3 on the opposite side of the plate I. By this arrangement and form of blades air picked up by the blades 3 passes through the respective aperture 4 of the plate and discharges into the respective arcuate blade 5 to discharge radially of the fan plate as indicated by the arrows in Fig. 3.

The fact that a lesser volume of air per unit of time is discharged into the blades 5 adjacent the axis of rotation of the fan plate and an increasing volume per unit of time at points successively greater in distance from the center of rotation provides a construction in which the larger volume of air discharging at the outer end of each of the arcuate blades 5 tends to cause a reduced pressure at the inner end of the arcuate blade resulting in a suction effect toward the said inner end and preventing discharge of air by the inner end of the blade 3 outwardly of the plate surface.

This arrangement of arcuate blades of a conelike form and angular blades of a triangular form therefore provides for discharge of greater volume of air per revolution peripherally of the fan than would be the case with plane faced blades on opposite sides of the fan plate as the air entering the arcuate blade 5 is caused to rotate as it enters the arcuate blade and is discharged in the form of a rotating spiral of least density at the inner end of the arcuate blade, the density increasing from the inner end of the blade toward the periphery of the fan due to the gradually increasing volume of air discharging to the arcuate blade from the companion inclined blades 3. It is this character and relationship of blades that in my opinion provides a greater volume of delivery of air radially from the fan per revolution than is produced by the usual fan having radial blades as my improved fan structure tends to provide an area of least pressure at the center of the face of the fan resulting in an increased flow of air from atmosphere to the center of rotation of the fan and where it is desired to provide a draft of air about the occupants.

In such use the fan may be mounted on a vertical shaft 1 of a motor 8 supported by a frame element 9 as indicated in Fig. 2. While an electric motor is the preferred means for rotat- I ing the fan other means may be employed as the invention herein disclosed is not confined to use of any specific driving mechanism as the features of the invention reside in the fan structure per se.

While I have described and shown a fan embodying my invention as being made of sheet material such as metal it is to be understood that it may be made of any approved material in any desired manner and that various other changes may be made in the fan structure without departing from the spirit and scope of the appended claims.

Having thus fully described my invention, its utility and mode of operation, what I claim and desire to secure by Letters Patent of the United States is 1. A rotary fan comprising a flat sheet metal plate rotatable on an axis at a right angle to its plane and having a series of apertures therein extending from near the center toward the periphery of the plate, a fan blade having an edge attached to the rear edge of each aperture and inclined to the plane of the plate and extending from the rear of each aperture and-forwardly thereof in the direction of rotation of the plate, a second fan blade on the opposite surface of the plate at each aperture having an edge attached to and extending rearwardly of the rear edge of the respective aperture and thence forwardly on a curve providing an arrangement whereby air picked up by the inclined blades on one side of the plate is discharged into the curved blades on opposite sides of the plate and discharged thereby radially of the fan.

2. A rotary fan comprising a comparatively thin plate rotatable on an axis at a right angle to its plane having a series of equi-dlstantly spaced apertures therein extending from near the center toward the periphery of the plate, a fan blade on one side of the plate at the rear of each aperture and extending forwardly at an angle to the plate in the direction of rotation of the plate, said blades each being of greater width adjacent the periphery than at the inner ends, a second blade at the rear of each aperture and on the opposite side of the plate from that occupied by the first named blades, said last named blades each being of the form of a half-cone with the smaller end adjacent the center of the plate into which air picked up by the first named blades in rotation of the plate is discharged radially of the plate.

3. A rotary fan comprising a plate attachable at its center to a rotatable element at a right. angle thereto and having apertures substantially radially disposed and equi-distantly spaced about the center, a blade struck outwardly to one side of the plate and extending from each aperture on one side of the plate at an angle thereto, and a curved blade having a straight edge attached to the plate at the edge of the aperture from which the first named blade extends, said curved blade extending outwardly from its respective aperture on the opposite side of the plate from which the first named blades extend and having an open side into which air picked up by the companion angularly disposed blade blows and is discharged thereby radially of the fan.

4. A rotary fan comprising a plate attachable at its center to a rotatable element extending at a right angle thereto and having equi-distantly spaced V shaped apertures extending from adjacent the periphery toward the center, the rear edge of the apertures each being tangent to acircle having its center at the center of the rotation of the plate, a pair of blades extending outwardly from opposite sides of the plate adjacent the rear edge of each aperture, the blades on one side of the plate being inclined to the plate and extending forwardly in the direction of rotation, and the companion blades on the opposite side of the plate each being of the form of a half-cone with the smaller end toward the center of the plate and into the open side of which air is discharged by the first named inclined blades and from the larger end of which air is discharged radially of the plate.

5. A rotary fan comprising a plate of circular form adapted at its center for attachment to a rotatable element extending at a right angle thereto, a series of blades struck outwardly from the surface of the plate and extending at an angle thereto on one side thereof and providing V shaped openings therein, a second series of blades on the opposite side of the plate each consisting of a sheet of material attached at one edge to the edge of the opening from which the first named blades extend and being curved in form, the free edges of both blades extending forwardly in the direction of rotation of the plate.

6. A rotary fan comprising a sheet metal plate of circular form adapted for attachment at its center to a rotatable element extending at a right angle thereto, a series of blades formed by portions of the plate struck outwardly from one face thereof to provide a free edge inclined to the plate surface from the rear of the opening forwardly in the direction of rotation of the plate, a second series of blades formed of sheet metal having a base portion attached to the opposite face of the plate at the base of the inclined blades and extending rearwardly and thence forwardlyto form a curved surface providing a blade having substantially the form of a half-cone, the small end of which is toward the center of the plate, both the said blades being of greatest width at their outer ends and providing a means for causing the air picked up by the angularly disposed blades in the rotation of the plate to discharge radially of the plate in increasing volume from the inner end of the armate blade toward the outer end.

PERCY WAREHAM.

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