US2838229A - Electric fan - Google Patents

Description

ELECTRIC FAN Filed Oct. 30. 195:5

INVENTOR I Aauvnm (Z' BEL4/V6'l 20 1 /5. 4. BY

ATTOR EYS United States Patent ELECTRIC FAN Roland J. Belanger, Bloomfield, N. J. Application October 30, 1953, Serial No. 389,365 3 Claims. (Cl. 230--254) This invention relates to electric fans, and more particularly to such fans which revolve as well as rotate.

It is common to mount a fan unit movably on a base in order to cool a greater area. A typical example is the mounting of pedestal or ceiling fan units for revolution about a support post, and in a known type of fan the revolution of the fan units is obtained by the reaction to the fan draft itself, for which purpose it is necessary merely to mount the fan unit with its axis offset somewhat from the axis of the support post.

The primary object of the present invention is to generally improve fans of the specified character. A more particular object is to provide means to vary the rate of movement or revolution of the fan units. A still more specific object is to provide such means which is automatically responsive to changes in temperature, in such sense that the fans will revolve more rapidly in hot weather, and more slowly in cool weather.

To accomplish the foregoing general objects, and other more specific objects which will hereinafter appear, my invention resides in the electric fan elements, and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by a drawing, in which:

Fig. 1 is a front elevation of a pedestal fan embodying features of my invention;

Fig. 2 is a horizontal section taken approximately in the plane of the line 2-2 of Fig. 1;

Fig. 3 is a vertical section taken approximately in the plane of the line 3-3 of Fig. 2;

Fig. 4 is a fragmentary vertical section taken centrally, as on the line 44 of Fig. 1, but in the plane of the supports arms; and

Fig. 5 is a miniature schematic View showing that the invention may be applied to a ceiling fan.

Referring to the drawing, and more particularly to Fig. 1, the fan here illustrated comprises two fan units 12 and 14 carried on radial arms 16 and 18, which are rotatably carried on an upright support post 20. The post 20 is supported on a base 28. The fan units may be conventional, and each comprises a motor 22, fan blades 24, and a protective screen or cage 26. The fan blades have been simplified for clarity, but in practice there may be four blades instead of two, each so wide as to overlap the next, all in accordance with present-day conventional efiicient silent fan design.

The fans 12 and 14 are oppositely faced or directed. Specifically, the fan 12 is shown blowing toward, and the fan 14 away from the observer. It will thus be apparent that the fan units will revolve about the post 20 without requiring any additional special mechanism for the purpose. Of course, a drive mechanism might be employed as is more commonly the case when a single fan unit is movably mounted, particularly if the movement is to be merely oscillatory instead of rotative, but in using my invention it is important that any such drive, if used, be a non-positive drive, that is, it should include a frictional connection at some point.

Any drive based on reaction to the fan draft itself, as in the fan here illustrated, is non-positive. If the torque tending to revolve the fans is excessive, the offset or length of the radial support arms may be reduced. In the alternative, and as is already known, the fans may be mounted at an angle, for the effective radius of oifset is the perpenricular distance between the fan shaft axis and the post axis.

Referring now to Fig. 3, electric current may be supplied to the fan through a conventional flexible supply cord 30, the free end of which (not shown) may have a conventional male plug for use with a conventional wall outlet. The cord passes into the base 28 through-an insulation grommet 32, and thence to a control switch 34, the handle or toggle lever 36 of which is exposed above the base. This may be a simple on-and-off switch, movable to the position indicated at 36. While shown with an oscillatable lever, a rotatable knob may equally well be employed.

From the switch 34 the current is supplied through conductors 40 to brush holders 42 and 44, stationarily mounted as by means of a bracket 46. The brush holders may be conventional and require no detailed description. The usual construction is to employ carbon brushes and light compression backing springs held in place by thread ed caps. The brushes bear against slip rings 52 and 54, which in turn are insulatedly mounted on the lower end of a pipe or tubular shaft 50. This is hollow so that conductors 56 may pass upwardly therethrough, one of the conductors being connected to the slip ring 52, and the other, to the slip ring 54. Referring now to Fig. 4, the conductors 56 at their upper ends are branched within a junction box 58 and extend outwardly through the support arms 16 and 18, as shown at 60 and 62, thus leading to the individual fan motors which, of course, are operated simultaneously, and electrically in parallel.

As so far described the fan units would revolve without any speed control or braking action. In accordance with the present invention I provide a liquid brake to control the revolution of the fan units, and the said brake contains a liquid the viscosity of which is sensitive to temperature change. More specifically I provide a crank means generally designated 64 (Figs. 2 and 3) and a plurality of dashpots 66 and 68. The dashpots and the crank means are so relatively disposed that the dashpots are efiective in displaced phase, thereby providing a continuous and substantially uniform braking action in any rotative position of the fan units. For this purpose a plurality of cylinders may be provided in superposed alignment, as in the engine block of an ordinary automobile engine, with the dashpot pistons connected to cranks which are angularly displaced relative to one another. However, in the specific case here showna single crank 64 is employed, and the dashpot cylinders 66 and 68 are angularly displaced. With only two dashpots as here shown they are preferably disposed in approximately relation, the dashpots being double-acting.

Considering the arrangement in greater detail, each dashpot comprises a cylinder which is closed at both ends except for the piston rod 70. It is unnecessary to provide a pivoted connecting rod, and instead the entire cylinder may be pivoted at its outer end as shown at 72 for cylinder 66, and at 74 for cylinder 68. Thus the cylinder oscillates as its piston reciprocates,

It will be understood that the fit of the piston in the cylinder is loose enough to permit the piston to pass through the enclosed body of liquid with the desired dashpot or braking action. If desired, the action may be made adjustable in accordance with known practice. One procedure is to provide a passage through the piston, this being adjustable by means of a screw acting as a, valve.

Another and more convenient procedure is to make the adjustment freely accessible on the outside of the cylinder by providing a bypass passage leading from one end of the cylinder to the other, the said passage having an adjusting screw intermediate its ends, with the screw acting as a valve. Such an arrangement is schematically indicated in Fig. 2 by the bypass pipes 76 and 78, with valve screws 80 and 82 respectively. This adjustment determines the ra te of revolution of the fan units at a specific ambient temperature.

The liquid employed is one the viscosity of which is sensitive to temperature change. This is true of most ordinary oils, but if it be desired to increase the degree of response to temperature change a special oil or other liquid may be selected which is particularly sensitive to temperature change. The viscosity decreases at higher temperature, and thus the speed of revolution increases when the weather is hotter, which is the desired result,

Reverting now to Fig. 3, the hollow shaft or tube 50 rotates Within a radial bearing 54, which in turn is supported Within the post 20. The latter is received within a flanged collar 86 secured to or forming a part of the base 28. The base is upwardly convex and is closed at the bottom by means of a removable bottom plate 88.

Referring now to Fig. 4, the upper end of post 20 is provided with a collar 90 which may be used as a thrust bearing to support the weight of the fan units. The bottom surface of the bottom wall 92 of the junction box acts as the mating bearing surface. A ball bearing may be interposed, although not shown. The junction box includes a sleeve portion 94 which is secured to the upper end of the rotatable tube 50. The said sleeve portion 94 may be used as a radial bearing. The junction box 58 is preferably made openable, as by using a top plate 96 secured by means of releasable screws.

Substantially the same arrangement may be used for a ceiling fan. Referring to Fig. 5, the fan units 100, 102 are rotatably secured in offset relation to an upright post 104. The latter depends from an inverted base 106 which may be secured directly to a ceiling at an electric outlet box. The fans point in opposite direction, and the inverted base 106 encloses a liquid brake containing a temperature sensitive variable viscosity liquid, as previously described. Except for the provision of a thrust bearing faced in opposite direction to that shown in Fig.4, and except for shortening of the post 104, this ceiling fan may be substantially the same as the floor fan previously described.

It is believed that the construction and operation of my improved electric fan, as well as the advantages thereof, will be apparent from the foregoing detailed description. When the fans are switched on, they gradually go into revolution around the post. The speed of revolution increases until exactly counterbalanced by the braking action of the dashpots, and then remains uniform. However, in hotter weather the speed of revolution automatically increases, and in cooler weather it automatically decreases. -It will also be apparent that while I have shown my invention in a preferred form, changes may be made in the structure shown, without departing from the scope of the invention, as sought to be defined in the following claims.

assaaas i I claim:

1. An electric fan of the revolving type comprising a support post, a fan unit carried by said post with its axis offset from the post axis in order to cause revolution of the fan unit about the post, slip rings and appropriate wiring from a source of power through said slip rings and to said fan in order to supply electric current to the revolving fan unit, and means to control the rate of revolution of the fan unit, said means including a crank means which revolves with the fans and a plurality of dashpots connected to said crank means, said dashpots and crank means being so relatively disposed that the dashpots are effective in displaced phase, said dashpots containing liquid the viscosity of which is sensitive to temperature change.

2. An electric fan of the revolving type comprising a support post, radial arms rotatably carried thereby, fan units carried by said arms and faced in such direction as to cause revolution of the fan units about the post by reaction of the fan draft, slip rings and appropriate wiring from a source of power through said slip rings and to said fan in order to supply electric current to the revolving fan units, and means to control the rate of revolution of the fan units, said means including a crank means which revolves with the fans and a plurality of dashpots connected to said crank means, said dashpots and crank means so relatively disposed that the dashpots are effective in displaced phase, said dashpots containing a liquid the viscosity of which is sensitive to temperature change.

' units carried by said arms and faced in such direction as to'cause revolution of the fan units about the post by reaction of the fan draft, slip rings and appropriate wiring from a source of power through said slip rings and to said fan in order to supply electric current to the revolving fan units, and means to control the rate of revolution of the fan units, said means including a crank which revolves with the fan units and two dashpots connected to said crank, said two dashpots being disposed in approximately ninety degree angular relation, said dashpots containing a liquid the viscosity of which is sensitive to temperature change, whereby the fan units revolve more rapidly in hot weather and more slowly incool weather.

References Cited in the tile of this patent UNITED STATES PATENTS 823,567 Waters June 19, 1906 1,295,618 Shaw Feb. 25, 1919 1,590,414 Bosserdet June 29, 1926 1,643,262 Steiner Sept. 20, 1927 1,905,502 Reid Apr. 25, 1933 2,027,662 Young Jan. 14, 1936 2,458,098 Primeaux Jan. 4, 1949 2,619,892 Babcock Dec. 2, 1952 2,741,971 Whelle'r Apr. 17, 1956

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