US1226076A

US1226076A - Revolving fan.

Info

Publication number: US1226076A
Application number: US78815A
Authority: US
Inventors: Oliver S Jennings
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1915-01-06
Filing date: 1915-01-06
Publication date: 1917-05-15
Anticipated expiration: 1934-05-15

Description

0. S. JENNINGS.

REVOLV ING FAN. APPLICATION FILED JAN. 6| I915.

Patented May 15, 1917.

2 SHEETS-SHEET I.

ATTORNEY 0. 3. JENNINGS. REVOLVING FAN.

APPLICATION FILED JAN- 6,1915.

Patented May15, 1917 2 SHEETS-SHEET 2.

INVENTOR "rinrrnn l ia itdihl OLIVER S. JENNINGS, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A. CORPORATION OF PENN- SYLVANIA.

REVOLVING FAN.

Specification of Letters Patent.

Patented May 15, 191?.

To (MU/17mmitmay concern:

Be it known that I, OLIVER S. JENNINGS, a citizen of the United States, and a resident of \Vilkinsbrnrg, in the county of AL legheny and State of Pennsylvania, have invented a new andfuseful Improvement in Revolving Fans, of which the fo-llowingis a specification.

My invention relates to rotary electric fans, and it has special reference to gyratory fans that are adapted to turn on an axis of rotation while Simultaneously and automatically turnil'lg around an axis of revolution.

One object oi. my invention is to provide a simple, inexpensive and rugged fan structure of theabove-indicated character which shall be auton'iatically driven around its axis of revolution at predetermined speeds by the reaction forces set up by the rotation of the fan blades.

Another object. of my invention is to provide convenient means for quickly chang ing the speed of revolution of the fan struc ture.

A further object of my invention is to provide means for maintaining the several fan structures constituting my device at equal angular relations with respect to the support which carries the fan structures.

Figure 1 isa side elevational view of a fan structure embodying my invention and Fig. 2 is a plan view of the structure shown in Fig. 1.

The device shownin the drawings comprises a bracket 1 rotatably supported, in any convenient manner, upon a hanger 2 and having outwardly and oppositely extending arms 3 and +L. Secured to the outer ends of the arms 3 and 4 are bearing members 5 and 6 whichare adapted to pivotally support, by means of pivot screws 7, a pair of trunnions 8 and 9 in which fan motors 10 and 11 are horizontally pivoted. Thumb screwslQ and 13 are provided to secure the fan motors 10 and 11 in adjusted tilted positions around their horizontal pivots. The armature shafts 14 and 15 of the fan motors 10 and 11 carry sets of fan blades 16' and 17. The details of the rotatable supportingmeans for the bracket 1. and of the fan motors with their fan blades form no part of my present invention, and will therefore not. be further described.

As shown in Fig. 1, the bearing members 5 and 6 are slightly inclined from the vertical, the angle of inclination being about five degrees in the structure shown. This inclination is sufficient to cause the fan motors to rotate about these inclined pivots by then own weight when the bracket 1 is at rest, and the direction of such inclination causes the

end brackets

18 and 19 of the fan motors 10 and 11 to approach the bracket arms 3 and 4, respectively. The trunnions 8 and 9, which carry the fan motors 10 and 11, are connected by a rod 20, one end of which is pivotally attached, at 21, to the trunnion 9, while the other end is pivotally attached, at 22, to a projection 23 formed on the trunnion 8. The points of attachment of the opposite ends of the rod 20 are so disposed that they are equidistant from the inclined pivots 7, and the fan motors are caused to move in unison and in the same direction around the inclined pivots 7 Stops 24 are formed on, or attached to, the bearing members 5 and 6 in order to limit the outward pivotal movement of the fan mo tors which is caused by the starting torque of the motors, when they are tilted downward at starting, and also to limit the effect of centrifugal force while the supporting bracket is rotating. These forces may, unless prevented by the stops,"or otherwise, rotate the fan motors far enough outward to bring the thrust axes of the fans up to or beyond the axis of rotation of the bracket, and the revolution of the bracket may thereby be interrupted or reversed. The starting torque of the motors may even throw the motors outward far enough to set the supporting bracket in rotation in the Wrong direction.

In order to assist centrifugal force in turning the fan motors outwardly around their pivots, Iprovide a spring 25 that is maintained in tension between a projection 26 formed on the bracket arm 3 and a screwthreaded hook 2'? which extends through an opening in. a projection 28 formed on the trunnion S. The tension of the spring 25 may be quickly and easily variedby means of a nut 29 disposed upon the screwthreaded portion of the hook 27 on the side of the projection 28 opposite to the spring. As shown in Fig. 2, the force of the spring is exerted along a line that passes the motor pivot 7 on the side opposite to the motor, and, tl'ierefore, the effect of, the spring is to arms. In this position, the axes of rotation erate to turn the fan motors outward around their respective inclined pivots in opposition to the force of gravity. Inthus turning the fan motor, centrifugal force is assisted by assist the rotation of the fan motor 10 in a counter clockwise d1rect1on,as lndicatcd in Fig. 2. This rotation s transmitted, to the fan motor 9 by means of the rod QOwhich,

as stated above, Causes the fan motors to pivotally move in unison. Instead of the spring 2-5, helical springs may be placed around the bearing members 5 and (5, one

end of each spring being in engagementwith the adjacent trunnionsupport and thus assisting theaction' of centrifugal force. In

this arrangement, each spring may be provided with means foradjustlng the torsion of its coils and thereby varying the pressure "which it exertsiqion the fan trunnion.

i The fan motors 10 and 11 may be supplied with electric energy in any convenient manner (not shown) which maybe controlled by means of a switch button 30.

Then the motors are horizontal, the supporting structure is at rest and the device is adjusted to revolve at relatively high speeds; the fan motors will, as stated, above, assume positions in which their rear brackets approach the adjacent bracket of the two sets of fan blades, that is to say,

the. axes of the armature shafts of the motors, lie on opposites'ides ofthe axis of rev,-

olutionof the bracket 2. In" this position,

the tension of thespringio, and the outwardpivotal movementof each fan-motor is continuousuntil the centrifugal force, to-

I gether with the tension of the spring, a re ex 'actly balanced by. the component of the thrust of the fan blades that tends to rotate the fan motor ina clockwise direction around its pivot, plus the weight of the motor multiplied by the sine of the angle to which its pivot is inclined. The proportions of the parts and the tension of the spring are so adjusted that, when the axes of the fan motors are horizontal, these opposing forcesbalance each other when the. motors aresin approximately the position shown in Fig. 2. The moment. arm. through which the motor thrust acts in driving the bracket around the axis of the hanger 2 is deter- .mined by the sum of the perpendicular distances from this axis to the projected axes of rotation of the fan motors. This combined distance is designated D in Fig. 2 and varies with the retarding force and downward tilt of the fans. The speed of rotation of the bracket may be varied by ma-- position of equilibrium will therefore be reached while the bracket is rotating at relatively low speed. The speed of rotation of the bracket may likewise be increased within wide limits by lessening the tension of the spring In practice, I have found that the speed of rotation of the bracket may readily be varied between 5 and QOrevolutions per minute.

The forces discussed above are complicated when the fan motors are tilted about the bracket is diminished by the cosine of the angle through which the axis of the fan motor is tilted; At the'same time, the horizontal component of the torque that drives the blades is added to or subtracted from the turning moment exerted upon the bracket, andis proportional to the sine of the angle of tilt. The direction in which the motor torque afi'ects the turning moment exerted upon the bracket depends upon the direction in which the fan blades revolve. I prefer that the torque of the motors shall assist the rotation of the supporting bracket, though the device may be adjusted to 0perate with the torque opposing the rotation of the bracket. Under these operating con:

ditions, rotating force acting to. move each fan motor outwardly around its inclined pivot is made up of the centrifugal force impressed upon the motor, plus the tension of the spring, and plus (or'minus) the torque of the motor multiplied by the sine of the angle through which the fan is tilted. When this compound force is balanced by themotor-turning component of the fan thrust, plus the weight moment of the motor multi plied by the sine of the angle of inclination of the pivot, the fan motor will be in stable equilibrium with reference to its pivot.

The downward tilting of the fan motors also causes variations in the relative positions of the parts of the device during its operation. If the motors are tilted through an angle of about 30, and the fan blades rotate in such a direction, that the torque of the motors assists in rotating the bracket, the torque effect of the motors is just sufficient to rotate the bracket with the fan motors in their position of stable, equilibrium, and

the axes of the fanmotors will then pass through the axis of rotation of the bracket, the distance D, Fig. 2, being reduced to zero. When the fan motors are tilted still further, the torqueeflect is greater than the retarding moment required to be overcome in rotating the bracket, and this excess torque causes the fan motors to rotate farther outward until the backward thrust effect balances; the excess torque effect. The axes of the motors are then on opposite sides of the axis of rotation of the bracket from their positions shown in Fig. 2.

It will be evident that revolving fans constructed in accordance with the principles discussed above are adapted to revolve ata variety of speeds, which may be readily selected and varied bysimple manipulation of the nut 29 which controls the tension of the spring 25, since this tension is the only variable factor of the forces which cause the structure to revolve when the fan motors are disposed at a given inclination. It will also be evident that the fan motors are caused to move in unison by means of the rod 20, which maintains the fan motors in equal an gular relations to the bracket, and that the driving forces impressed upon the structure are always regulated in accordance with the resistance to turning offered by the structure.

Numerousstructural modifications may be effected in my device without departing from the principles of my invention, and it is therefore to be understood that my invention comprehends all such changes and modifications as fall within the scope of the appended claims.

I claim as my invention:

1. The combination witha rotatable supporting member provided with an inclined pivot member, of a rotatable fan pivotally mounted upon the said pivot member, where by the said fan tends torotate under the influence of gravity around the said pivot.

2. The combination with a rotatable supporting member provided with an inclined pivot for supporting a rotatable fan, of means for opposing the tendency of the said fan to rotate under the influence of gravity around the said pivot.

3. The combination with a rotatable supporting member provided with an inclined pivot for supporting a rotatable fan, of a spring adapted to oppose the tendency of the 'said fan to rotate under the influence of gravity arounclthe said pivot.

l. The combination with a rotatable supporting member provided with an inclined pivot member, of a rotatable fan pivotally supported by the said pivot member and adapted to be pivotally moved thereon by centrifugal force during the rotation of the said supporting member, and a stop associated with the said supportingmember for limiting the degree of such ment ofthe said fan.

5. The combination with a rotatable supporting member provided with an inclined pivot member, of a rotatable fan pivotally mounted upon the said pivot member and adapted to be pivotally moved in one direction under the influence of gravity and also adapted to be pivotally moved in the opposite direction by centrifugal force during the rotation of the said supporting member.

6. The combination with a rotatable sup porting member provided with an inclined pivot member, ofa rotatable fan pivotally mounted upon the said pivot member and adapted to be pivotally moved in one direction under the influence of gravity and also adapted to be pivotally moved in the oppositc direction bycentrifugal force during the rotation of the said supporting member, and means for assisting the action of centrifugal force in pivotally moving the said fan.

pivotal move- 7. The combination with a rotatable supporting member provided with an inclined pivot member, of a rotatable fan pivotally mounted upon the said pivot member and adapted to be pivotally moved in one direction under the influence of gravity and also adapted to be pivotally moved in the opposite direction by centrifugal force during the rotation of the said supporting member, and a spring for assisting the action of centrifugal force in pivotally moving the said fan.

8. The combination with a rotatable sup porting member provided with an inclined pivot member, of a rotatable fan pivotally mounted upon the said pivot member and adapted to be pivotally moved in onedirection under the influence of gravity and also adapted to be pivotally moved in the opposite direction by centrifugal force during the rotation of the said supportin member, a spring for assisting the action 0 centrifugal force in pivotally moving the said fan, and means for varying the eifect of the said spring.

9. The combination with a rotatable supporting member provided with an inclined pivot member, of a rotatable fan pivotally mounted upon the said pivot member and adapted to be pivotally moved in one direction under the influence of gravity and also adapted to be pivotally moved inthe opposite direction by centrifugal force during the rotation of the said supporting member, and a tension spring secured at one end to the said supporting member and at the other end to the said fan, the said fan and the line along which the tension of the said spring is exerted being disposed on opposite. sides of the said pivot member.

10. The combination with a rotatable supporting member provided with an inclined pivot member, of a rotatable fan pivotally mounted upon the said pivot member and adapted to be pivotally movedin one direction under the influence of gravity andalso adapted to be pivotally moved in'the opposite direction by centrifugaliorce during the rotation of the said supporting member, a spring secured at one end to the said supporting member and at the other, end to the said "fan, and means for manually varying the tensionnof the said spring.

11. The combinationvvith arotat'able supporting member, of two fan's pivotally supported on the said member, and a rod pivoted at itsends to the saidians."

12. The combination With a rotatable supporting member of tWO fanspivotally supported'on the said member, and a rod pivotally secured, at its ends, to the said fans, the points ofattachment of the ends of the said rod to the said fans being substantially equidistant from the respective pivotal axes of the said fans. a i p 13. The combination with a rotatable supportingmember, of two'fans pivotally supported on the said member, and a rod pivotally secured, at-its endsg to the said fans,

Copies of this patentmay be obtained for equidistant from the respective pivotal axes of the 'said'fans and being so dispo'sedivith t relation to the'said pivoted axes that the said fans are permitted to move pivotally in the same direction. g

14. The combination with arotatable supporting member provided With an inclined pivot member, of a rotatable fan pivotally supported by the i said pivot member and adapted to be pivotally moved thereon by the reaction of the said fan and by centrifuif'orce during the rotation of the said supporting member, and a stop associated with the said supporting member for limiting the degree of such pivotal movement of the said fan.

In testimony whereof, I have hereunto subscribed my name this 30th day of Dec. 1914.

Witnesses:

, R. D. BROWN, B. B; I-IiNns.

five cents each, by addressing the Commissioner of Patents. Washington; I). B.

OLIVER S. JENNINGS.