US 2652974 A
Description (OCR text may contain errors)
Sept. 22, 1953 M, G, FETTEL 2,652,974
ELECTRIC FAN Filed May l5, 1950 fr INVENTOR. lwwf/Af a Ffa Patented Sept. 22, 1953 UNITED STATES PATENT OFFICE ELECTRIC FAN Martin G. Fettel, Cleveland, Ohio Application May 15, 1950, Serial No. 162,070
6 claims. (ol. 23o-254) This invention relates to electric fans and more particularly to an improved fan of the type designed to continuously rotate on a fixed base to direct air currents radially through all degrees of a circle.
It is among the objects of my invention to provide a simple, inexpensive and sturdy fan construction of the foregoing character which shall be automatically rotated about its supporting axis at predetermined speeds by reaction forces set up by the rotation of the fan blades.
It is another object of the invention to provide, in a continuously rotating fan, means for controlling and varying the speed of rotation of the fan within predetermined limits.
A still further object of the invention is to provide, in a unitary fan construction, means whereby the reactive forces set up by the rotation of the fan blades may be utilized to control the speed of rotation of the fan thereby eliminating the necessity of using mechanical means for controlling rotatory speed.
These and other objects and advantageous features of the invention not at this time more particularly pointed out will become more apparent as the nature of the invention is better understood from the following detailed description taken in conjunction with the accompanying drawing, wherein. like reference characters denote corresponding parts, and wherein:
Figure 1 is a fragmentary sectional View of a fan embodying the present invention,
Figure 2 is a fragmentary side elevational View partly in section taken along the line 2 2 of Fig ure .1, and
Figure 3 is a view similar to Figure 2 illustratn ing the fan disposed at an angle to a vertical plane through the supporting bracket therefor.
With reference to the accompanying drawing there is illustrated a fan constructed in accordance with the teachings of the present invention including a hollow stationary base 0 which is preferably circular in plan view but may be square or irregularly shaped, if desired. The inner wall surface of the base I6 has secured thereto at spaced points about the periphery thereof, angular members II to which a bottom closure plate I2 may be secured by means of bolts I3. Projecting upwardly from the central portion of the base I6 is a tubular supporting housing lil suitably provided with anti-friction bearings l and I6 adjacent each end thereof. Journalled in the bearings I5 and I6 is a spindle Il :which projects downwardly below the housing Hi and is provided With a tubular insulating collar I8. The outer surface of the collar I8 is provided with spaced circular contact rings i3 and I9a having wiping, continuous contact with contact members 23 and 2| of fittings 20a and 2Ia, respectively, which in turn are secured to the ends of lead in wires 22 and 23. The fittings 26a and 2Ia are suitably supported by and insulated from a bracket member 24 suspended from the inner wall of the base I0.
Mounted on the upper end of the spindle Il' for rotation therewith is a substantially U-shaped bracket member 25. The point of securement of the base portion of the bracket member 25 to the end of the spindle is olf-center so that a gyratory movement may be effected between the bracket and the axis of the spindle as the bracket is rotated thereabout. The ends of the bracket 25 are suitably apertured to receive outwardly extending trunnions 26 and 2l carried on the housing of a motor 28. A fan 29 is suitably mounted on the outer end of the drive shaft of the motor 2B and a fan guard 30 surrounding the fan is supported on the housing of the motor 28. Current is conveyed to the motor 28 from the rings I9 through conductors 3|.
The fan 29, fan guard 30 and motor 28 are pivotly supported in bracket 25 in such a manner that the center of gravity of the assembly is forward of the point of support. Therefore, the weight of these elements is such that they are urged in a counterclockwise direction about their pivotal support when viewed as in Figures 2 and 3. In opposition to this downward movement there is provided a clock spring 33, the convolutions of which encircle the trunnion 2'I with the inner end of the spring being anchored to the trunnion as at 3ft. The free end 35 of the spring 33 is adapted to engage any one of a plurality of spaced lugs 36 formed in a clip secured to the side of the U-shaped bracket member 25. Placing the end 35 of the spring 33 behind one of the lugs 36 puts the spring under tension which in turn applies torque to the trunnion 2l thereby rotating the motor assembly about its pivot point and positioning the fan at an angle to a vertical plane through the axis of the supporting spindle I l. The amount of torque applied and the resultant angulation of the fan may be varied by the selection of the particular lug 36 with which the spring portion 35 is caused to engage.
When the fan parts are in the position shown in Figure 2 and the fan is in a position substantially parallel to the axis of the spindle Il the fan may be used as a fixed direction fan as reactive forces developed are not suilicient to ef= fect rotation of the fan about its supporting axis.
When the current is applied and the fan is in operation the back pressure created, acting through the bracket causes the motor, fan and all other rotating parts to revolve about the axis of the spindle l? in which case the centrifugal action or force acting upon the motor and i an assembly pivots the same downwardly against the pressure of the spring S3 to such an angular position that a uniform speed of rotation is obtained. The resultant angular position differs in accordance with the particular lug 36 with which spring 33 is caused to engage and therefore the speed of rotation of the fan differs with each position. However, in each case speed control is obtained by automatically adjusting the angular relationship between the plane in which the fan blades rotate and the plane through the center of the spindle, this being accomplished by a readjustment of parts as the various forces present during operation establish a condition of equilibrium.
From the foregoing it is believed that the construction and operation of my fan will be readily apparent to one skilled in the art, however, it is pointed out that it is merely necessary to turn on the current to start the fan in which case all other action is automatic except when it is desired to change the rotative speed oi the ian which is accomplished by manually adjusting the spring 33 to one of the designated positions.
Having thus described my invention, what I desire to obtain by Letters Patent is defined in the appended claims:
l. An electric fan comprising a base, a bracket member mounted for free rotational movement on said base, a plurality of spaced lugs projecting from one side of said bracket, a motor and a fan driven thereby mounted in said bracket, the axis of said motor and fan being oiset with respect to the axis of rotation of said bracket whereby upon actuation of said fan reactive forces are created to effect rotation oi the bracket and the fan carried thereby, said motor being pivotly mounted in said supporting bracket for movement about an axis traversing the axis of rotation oi the bracket, and a clock spring encircling the pivotal mounting of the motor supporting bracket having the inner end thereof secured thereto and the outer end free to engage one of said lugs whereby the rotational speed of the fan may be controlled through spring tension applied to said pivotal mounting.
2. An electric ian comprising a base, a vertically disposed spindle mounted in said base, an ofiset bracket mounted on one end of said spindle, a motor and ian driven thereby carrying trunnions journaled in said bracket for pivotal movement whereby upon rotation of said fan the bracket carrying the same is caused to rotate about the axis of the spindle and the fan to pivct within the bracket toward a vertical plane, a clock spring encircling one of said trunnions having the inner end thereof secured to the trunnion and means on said bracket for receiving the outer free end or said spring in one of a plurality of selected positions whereby the rotational speed of the fan may be controlled through spring tension applied to said trunnion.
3. An electric fan comprising a base, a vertically disposed spindle mounted in said base, a bracket mounted on the upper end of said spindle, a ian and a motor for driving the same carrying trunnions journaled in said bracket so that the center of gravity of the fan and motor assembly is forward of the point of pivotal support, the
axis of said motor and fan being offset with respect to the axis of rotation of the spindle Whereby upon actuation of said fan reactive forces are set up effecting the rotation of the bracket and ian carried thereby, a clock spring encircling one of said trunnions having the inner end secured to the trunnion and means on said bracket for securing the outer end oi the spring in one of a plurality of selected positions to pivot the fan within the bracket into a plane disposed at an angle to a plane through the axis of the spindle against the reaction forces and thereby assure rotative movement of the bracket and ian carried thereby.
4. An electric fan comprising a base, a vertically disposed spindle mounted in said base, a motor and fan driven thereby carrying trunnions journaled in a bracket mounted on the upper end of said spindle, a clock spring encircling one of said trunnions having the inner end secured to the trunnion, means for selectively securing the outer end of said spring to the bracket at spaced points, said spring adapted to apply variable spring pressure upon the pivot axis o said motor in opposition to the downward rotation of the motor, the axis of said motor and fan being offset with respect to the axis of rotation of said spindle whereby upon actuation of said motor and fan external forces are created to actuate said spindle, said spindle adapted to rotate at variable predetermined speeds in response to variations in pressure applied by said clock spring.
5. An electric ian comprising a base, a vertically disposed spindle mounted in said base and carrying an offset bracket on the upper end thereof, a fan and motor for driving the same carrying trunnions journaled in said bracket whereby upon actuation of said ian reaction forces are created to effect rotation of the spindle and the fan and motor carried thereby, and means for varying the angulation of the ian with respect to the axis of the spindle with a resultant variation in the rotative speed of the spindle said means including a clock spring encircling one of said trunnions and having the inner end secured to the trunnion and spaced lugs on said bracket for receiving the free end o said spring in one of a plurality of positions.
6. An electric fan comprising a base, a bracket member supported in an off center position with respect to said base, a ian and motor for driving the saine carrying trunnions journaled in said bracket member with the center of gravity thereof forward of the pivotal support a clock spring encircling one of said trunnions having the inner end secured to said trunnion and means on said bracket for securing the free end of said spring in one of a plurality of positions adapted to vary the angulation of the fan with respect to a transverse medial plane through said bracket member and thereby control the rotative speed of the bracket and the fan carried thereby.
M'AR'I'IN G. FETTEL.
References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 421,014 Polk Feb. 11, 1890 2,027,662 Young Jan. 14, 1936 FOREIGN PATENTS Number Country Date 520,760 Great Britain May 2, 1940