US2656974A - Window fan support - Google Patents

Description

Oct. 27, 1953 A. w. HOLSTEIN wINDow FAN SUPPORT Filed July 18, 1952 Patented Oct. 27, 1953 WINDOW FAN surnom Alvin W; Holstein, St. Louis, Mo., assignor` to` Knapp-Monarch Company, St. Louis, Mo., a

corporation ofDelaware Application July 18; 1952S`eria1N0- 29526.85 comme.V (o1. esos- 259i The present` invention relates to an improved support arrangement for an electric fan, particularly an electric fan of the soecalled windowA type.

Electric fans intended for domestic use must be silent in operation, otherwise the` occupants of the room ventilated are annoyed by the hum and other sounds issuing from the fan. Such.

sounds tend to bel amplified and. rendered more annoying when. they are communicated` to the various structures supporting the fan, and: for

this reason it isrhighly desirable to'. isolate the motor and fanA blades-which inherently execute vibrator-y motion' by reason of. the magnetic and: mechanical effectsl within theA motor-from the other portions off theiunit.

Vibration mounts tol isolate the motor` and ian blades from the` remainder of the fan, have not proven entirely satisfactory because; it is necessary to provide a support that does not ac. cent the motions executed by the motor andv fan blades themselves. Even if such motions are relatively silent, if their amplitude becomes un duly great, there isdanger of the` blades striking the. wire guard` or other stationary portions or the. mechanism and, in addition, the user of the fan, does not regard this as normal operas tion and is unsatisfied; On the other hand, if the vibration isolating mount is madeless elastic sothat themotor and fan blades are less free to move, the purpose of the vibration isolating device is defeated and` the vibrations are, communicated to the noise-creating wire guard and otherparts of the unit.

These difiioulties are overcome to a great` extent by the present invention by providing an improvedlmounting structure or support arrangement for the electric fantmotor andblades which supports the motor in the plane transverse to the motor shaft and passing through the center of gravity of the unit. With this support, it is possible to use a relatively elastic vibrationisolating structurev since. the motor and. blades do not then execute excessiveV movements. and the user is not annoyed by, what appears to be improper operation.

It is, therefore, af general object ofthe present invention to provide an improved vibration isolating support ioran electric fan.

A further object ofI the present invention is tof provide` an. improved vibration isolating support for an electric fan which supports the motor and fan blades in amanner that achieves highly effectivel vibration,` isolation and yet at the same timerdoesnot entail excessive movementsof the motor and blades.

Stillanother object ofthe present invention. is4 to' provide an improved vibration isolatingrsup` port` for an electric fan which supports. theA ian4 from the wire guard and in a planeA passing through the center of gravity of the motor and blades and perpendicular tothe-axis of the motor shaft.

t is also an object ofA the` present invention to achieve the foregoing obg'ects in a structure that is simple in construction, reliable in operation, gives rise to easy maintenance; and` isin, expensive to manufacture;

The novel features whichI believerto be char@ acteristic of my invention are set forth with` par ticularity in the4 appended-'f claims. My invention itself, however? bothas to its organization and method of operation, will best be `understood, by reference to the following description taken in connection with the accompanying drawings,

f in which:I

Figure 1 is a flront elevational View or a window fan constructediin accordance with` the present invention;

Figure 2 is a crossesectional view through axis 2-2, Figure 1;

Figure" 3 is a` fragmentary cross-sectional. view through axis .3L-3, Figure 2;

Figuren is aisomewhat enlarged fragmentary View through axis 4 4, Figure` 3; and.

Figure- 5Y is a somewhat enlarged; fragmentary view through axis 5"-5, f Figure. 3L

Referring now-tol Figures 1. and 2, the fan strucf ture consists of a Wire guardv indicated generally at l0. Thisguardis deiinedfby a series ofV radial struts or ribs I2; to which are welded:` the spiral wire M to forma spider web type coniiguration. Four ofthe ribs lf2" form outboard: eyelets 12a to receive mounting screws or bolts to support the structure. The inner margin ofthe guard t0 is defined bya circular wire lawhichis of somewhat heavier. construction than the wire lli` and is welded to the ribs i121. guard is defined by` the circular wire i8 somewhat heavier than Wire M: which is likewisewelded to the ribs I `2. It will bei observed that the ribs i2:4 extend rearwardly adjacent their outer margins so that thelfan blade2i) isprotected from both the front and the side.

At their inner margins the ribs I2 extend axially and'rearwardlyfin relation to the guard. These portions are indicated at If2b, Figures 2, 3,. and 4; At their rearward :terminus these ribs are welded to a circular Wire 22 which is seen in Figures 4 and 3. A strap` 244 ofV split sleeve conformation is secured by welding, orlotherwise, tothe axially extending portions; [2h of; the ribs` |2in theispace The outer margin of the;

between the marginal ring 22 and the radially extending portions of the ribs I2 =to define a cylindrical surface upon which the resilient members 34 seat.

A pair of wire rings 26 encircle the sleeve 24 as shown in Figures 3 and 4. These rings are split and receive the ear-brackets 26a at their split portions. As shown in Figure 2, these brackets extend across both rings 26, being secured thereto by welding or similar means. At their downturned portions, as shown in Figure 3, the brackets 26a have holes which receive the bolts 2B. Nut 30 on this bolt provides an adjustable tightening of the rings 26.

Four rearwardly extending brackets 32 are secured to the outer edges of the rings 26 by welding or similar means. 'Ihese brackets are formed of wire and in part extend rearwardly as shown in Figure 4 and in part extend inwardly as at 32a, Figure 4. Eyelets 32D are formed by these brackets at their radially inward extremes yas shown in Figures 1 and 3.

Four resilient inserts of rubber or the like, indicated at 34, Figure 3, are sandwiched between the sleeve 24 and the rings 26. As shown in Figure 4, these resilient inserts have flange portions 34a which cage the rings 26 to anchor the rings against axial movement. It will be noted that the members or inserts 34 define ia plane passing through their centers of gravity which is perpendicular to the axis of shaft 40. This plane is the plane of the cross-section of Figure 3.

The fan driving motor 36, Figure 2, is secured tothe eyelets 32h by the studs 36a, each of which receives a mounting nut 38. As shown in Figure 2, the body of the motor 36 extends within the confines of the sleeve 24 and the shaft Mi extends into the guard Il). A fan blade indicated generally at 20 is mounted on the free end of shaft B and hence within the connes of the guard l0.

The axial extent of the brackets 32 is of such amount as ito position the center of gravity of the motor 36 and blade 20 in the plane deiined by ithe sleeve 24 and perpendicular to the axis 0f shaft 40. This is the plane of the crosssection of Figure 3.

By reason of the foregoing construction, vibration motions of the motor 36 and blade 20 in the radial direction of shaft 40 act only to compress or relax the inserts 34 and do not tend to cause any twisting deilections of these inserts. I have discovered that the radial movements of the motor are the ones principally responsible for the annoying noise produced by the structure. However, since these motions in the above described structure produce only compressive effects on the rubber inserts, it is possible to use a rubber or other elastic material which is quite flexible and resilient and therefore highly effective for purposes of vibration isolation. Yet, the movements of the motor and blade, so long as they are conned to the twisting movements in directions perpendicular to shaft 4i), are not undesirable and in fact can be tolerated without annoyance.

The vibration isolating structure above described does not have the same flexibility with reference to twisting motions of the motor 36 and blade 20 as it has in relation to shifting moition radially of shaft dii., This is due Ito the presence of the overhanging portions 34a, Figure 4, of the inserts 34 and to the inherent characteristics of the structure. Thus the motor 36 and the blade 20 are rather rigidly mounted in relation to twisting movements and there is no opportunity for such movements to reach excessive magnitude. However, I have discovered that such twisting movements are not the movements that give rise to annoying noise and that the fan operation is relatively silent despite the rather rigid anchorage of the motor and fan blade with respect to such movements.

While I have shown and described a speciiic embodiment of the present invention, it will, of course, be understood that various modifications and alternative constructions can be made without departing from the true spirit and scope thereof. I therefore intend by the appended claims to cover all modifications and all alternative constructions falling within their true spirit and scope.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A support arrangement for an electric fan comprising in combination; a guard screen dening an axis and having a central motor-receiving opening, the screen further having radially directed ribs with axially extending portions at the margin of said opening; a sleeve encircling the axially extending portions of said ribs; elastic members interposed between the sleeve and said axial portions of said ribs, the centers of the elastic members defining a plane perpendicular to said axis; axially extending brackets secured to said sleeve and at their free ends extending radially inwardly to denne motorsupporting elements; a motor secured to said elements and within the confines of said opening; a fan blade on said motor and within the confines of the guard, the center of gravity of the blade and motor being in substantially the same plane as said plane defined by the elastic meinbers.

2. A support arrangement for an electric fan comprising in combination, a guard screen defined by generally circumferential coplanar members encircling an axis, the screen having a central motor-receiving opening and radially extending ribs with axially extending portions at the margin of said opening; brackets extending in part substantially parallel to the axially extending portions of the ribs and in part extending radially inwardly to define motor-supporting elements; resilient elements interposed between the axially extending ,portions of the ribs and the axially extending parts of the brackets, the resilient elements deiining a plane parallel to the plane of the screen; a motor secured to the brackets within the confines of said opening; a fan blade on the motor, the center of gravity of the motor and blade being substantially in said last plane.

3. A support arrangement for an electric fan comprising in combination, a guard screen defined by generally circumferential coplanar members encircling an axis, the screen having a central motor-receiving opening; means extending parallel to said axis at the margin of said opening and secured to said screen; brackets in part overlaying said means and in part extending radially inwardly to denne motor-supporting elements; resilient elements interposed between said means and the part of the brackets overlaying said means, the resilient elements defining a plane parallel to the plane of the screen; a motor secured to the brackets within the connes of said opening; a fan blade on the motor and within the guard, the center of gravity of the motor and blade being substantially in said last plane.

4. A support arrangement for an electric fan comprising in combination, a guard screen dening an axis and having central motor-receiving opening, the screen further having radially directed ribs with axially extending portions at the margins of said opening; split sleeve encircling the axially extending portions of said ribs; elastic members interposed between the sleeve and the axial portions of said ribs, the centers of the elastic members defining a plane perpendicular to said axis; adjustable means to tighten the sleeve about the elastic members; axially extending brackets secured to said sleeve and at their free ends extending radially inwardly to dene motor-supporting elements; a motor secured to said elements and within the confines of said opening a fan blade on the motor and within the connes of the guard, the center of gravity of the fan blade and motor being substantially in the plane dened by the elastic members.

5. `A support arrangement for an electric fan comprising in combination; a guard screen defining an axis and having a central motor-receiving opening, the screen further having radially directed ribs with axially extending portions at the margins of said opening; a rst sleeve afllxed to said radially extending portions of the ribs; a split sleeve encircling said rst sleeve; elastic members interposed between said sleeves and having overhanging portions centering said split sleeve, the centers of said elastic members defining a plane perpendicular to said axis; axially extending brackets secured tosaid last sleeve and at their free ends extending radially 1nwardly to dene motor-supporting elements; a-

motor secured to said elements and within the confines of said opening; and a fan blade on the motor, the center of gravity of the blade and motor being in substantially the same plane as said plane dened by the elastic members.

ALVIN W. HOLSTEIN.

No references cited.

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