US2155611A - Fan - Google Patents

Description

April 1939- c. E. MEYERHOEFER 2,155,611

FAN

Filed Aug. 12, 1957 2 Sheets-Sheet 1 INVENTOR I ATTORN EYS A ril 25, 1939. c; E. MEYERHOEFER ,1

FAN

Filed Aug. 12, 1937 2 Sheets-Sheet 2 INVENTOR ('ai'l E MIqer/we er M. KMM

ATTORNEYS Patented Apr. 25, 1939 UNITED ST TES PATENT orrice assiznor N. Y... a

Application August 12, 1931, Serial No. 15am 7 Claims.

This invention relates to a structurally and functionally improved fan as well as an improved method of providing the same.

In its more specific aspects it is an object of the invention to furnish a fan which will preferably be driven by an electric motor, and the body of which fan will be constructed of yielding material so that no injury can result to persons who contact the blades of the fans even when the latter is in motion.

A further object of the invention is that o! furnishing a fan which, with minimum R. P. M. and size will deliver a maximum volume of air.

A- still further object-is that .of constructing a fan which under all normal conditions of operation, will maintain a proper and predetermined configuration, such that even under varying speeds and under long periods of continuing use, the fan will operate with high eficiency.

An additional object is that of providing a unit of this character which will embody relatively few parts, each simple and rugged in construction and capable of manufacture and assembly by an improved method to furnish an article which may be sold at a nominal figure, and which will operate over long periods of time with freedom from all difilculties. However, the method of manufacturing herein taught, will be such that it may be practiced by relatively unskilled labor, and largely by automatic machinery, thus permitting of still further reduction in manufacturing costs.

With these and other objects in mind, reference is had to the attached sheets oi drawings, illustrating one practical embodiment of the invention, and in which:

Fig. 1 is a face view of a blade assembly;

Fig. 2 is an edge view thereof;

Fig. 3 is a view similar to Fig. l, but showing the parts after they have been shaped or formed;

Fig. 4 is an edge view of the unit as illustrated in Fig. 3;

Fig. 5 is a front view of a complete fan;

Fig. 6 is a fragmentary transverse sectional view taken along the line t-b and in the direction of the arrows as indicated in Fig. 5;

Fig. '7 is a rear view of the hub with a portion of the cover plate broken away to disclose underlying construction;

Fig. 8 is a view similar to Fig. 5 but showing the specific relation of certain portions of the blades with respect to the mounting member, therefor; and

Fig. 9 is a side view of the mounting member with certain of its portions broken away to disclose underlying construction and with certain of the blade portions shown in section.

In these several views, the numeral Ill indicates a body of material which is preferably resilcc lent. To this end the body may be formed of rubber or any other iunctionally equivalent substance. While any desired configuration may be imparted to the body, it is preferred that it include a pair of blade sections it and It. The base of each of these sections merges into a central or perforated collar portion. Moreover, one of the edges, and preferably the trailing edge of each blade is extended adjacent its base to provide a projecting portion i8 extending generally parallel to the edge or collar portion l3, and separated therefrom by an arcuate slot i5. Adlacent the base or the forward edge of each blade a notch 66 may be provided.

After a dy such as that just described, is furnished, there is applied thereto a pair of arouate strips ll, these being secured in position in any desired manner; as for example, by rivets it. At this time it will be noted that strips ii are not initially concentrically disposed with respect to collar 7 However, a further step of manufacture is now resorted to which includes bending strips l'l so that they are longitudinally curved throughout a more or less constant radius. Under suchcurvature they assume the positions shown in Figs. 3 and d, and under these circumstances extend more or less concentrically with respect to the edges of collar portion 53.

A fan hub is furnished preferably by die casting. This hub may include a cup shaped nose 09 from which a socket portion to extends. The edges of this body have extending irom them lugs 2 i, and a cover 22 is furnished which has a diameter substantially equivalent to that oi the cup and is provided with bayonet slots 23 for cooperation with the lugs. Moreover the cover is furnished with an opening through which socket 2d extends. At this time it will additionally be noted that cup 09 may have an opening 24 through which access may be had to a set screw 25 intended for locking the assembly against movement with respect to a driving shaft 26,.

A plurality of spirally extending slots (in the present instance four in number) are formed in the nose portion it. These slots are identified by the numeral 21 and have entrance portions extending perpendicular to the edge of cup I9; their bodies extending thence inwardly towards the apex or base of such cup.

Accordingly with a pair of elements as shown in Figs. 3 and 4, an operator may simply thread the blades into the entrance portions or these slots and thence inwardly. Collar It, of course, encircles socket 2t, and strips i1 lie between this collar and the inner face of the cup IS. The blade is thus properly rigidified and braced within the cup. 0f course, due to the provision of strip I1 and the particular disposition of the rivets M or their equivalents, the centrifugal force generated, will not result in an undue stretching-and conof slots 21 and also overlie the outer face of the cup member as also shown in the last mentioned figures.

Thus it is apparent that adjacent its eiiective base portion the blade is substantially rigid. In

other words, immediately adjacent the outer face of the cup member no movement of the blade bodies can occur. Incident to the interior bracing which exists, the blade under all normal conditions of operation is substantially rigid throughout its entire operative service. Of course, iffthe blade should forcibly contact a solid element, it

would flex. Accordingly a person placing their finger in the path of travel of the fan would not be injured.

It is additionally to be noted, as particularly illbstrated in Fig. 9, that as the cover plate 22 is moved to seated position, its edge will contact the blade throughout a zone adjacent the trailing edge of the latter so that:

A. The blade will be further supportedat this point, and

B. Incident to the inherent resiliency of the blade, the cover will constantly be urged outwardly so that it will not become accidently displaced with reference to the cup. I

Of course, incident tothe projecting portions l4 and the similar portions which define the outer edges of notches i 6, a slight compressive strain 'will be exerted upon the blade such that it will constantly tend to maintain its proper and normal condition.

From the foregoing it will be understood that among others, the several objects of the invention as specifically afore noted, are achieved. 0bviously, numerous changes in construction and rearrangements of the parts might be resorted to and the steps of the method might be altered without departing from the spirit of the invention as defined by the claims.

I claim:

1. A fan assembly including in combination a cup shaped member formed with spirally extending slots, a body of resilient material comprising a pair of blade portions and a central portion integral with and connecting said blade portions, said blade portions being threaded into said slots and said central portion being disposed within said member, and projections forming a part of said blade portions and overlying and in contact with the outer-surface of said member.

2. A fan assembly including in combination a cup shaped member formed with spirally extending slots, a body of resilient material comprising blade portions and a central portion, said blade portions being threaded into said slots, and separate rigidiiying strips secured to the faces of said blades and having a curvature substantially equal to that of said slots, said strips maintaining at least the blade portions adjacent which they are disposed in a curved condition.

3. A fan assembly including in combination a cup shaped member formed with spirally extending slots, a body of resilient material comprisagainst accidental ing blade portions ani a central portion, said I blade portions being threaded into said slots, proface of said member, and a cover plate for said member and yieldingly engaged by certain of said projections whereby said cover is maintained displacement with respect to said member.

4. A fan including, in combination, a blade formed of resilient and flexible material, and tending normally to return to a flat condition, said blade including a bodyfiand a narrow strip of substantially non-resilient material applied to one of and carried by the faces of said body, said strip having its inner edge substantially in line with the inner edge of said bladeand being curved longitudinally and in a direction transverse to its side faces, said strip maintaining said blade body in a condition of transverse curvature.

5. A fan including, in combination, a. blade formed of resilient and flexible material, and tending normally to return to a flat condition, said blade including a body, and a strip of substantially non-resilient material applied to one of the faces of said body, said strip being curved longitudinally of its body and in a direction transverse to its side faces, said strip maintaining said blade body in a condition of transverse curvature, and a mounting member for said blade and including a body formed with a slit, said blade extending through said slit and beyond said body, said strip being disposed within said mounting body and being engageable with the inner surface thereof to prevent a withdrawal of said blade through said slit.

6. As an article of manufacture a fan blade assembly including a normally flat sheet of resilient and flexible material, blade bodies forming a part of said sheet, a hubportion also forming a part of said sheet and connecting the inner ends of said blades-to each other, said bodies being formed with arcuately extending slits partially defining the outer edgescf said hub portion and the inner edges of said blades, and relatively narrow strips of substantially rigid material applied to said blade bodies, at points beyond said slits, said strips being curved to partially encircle said hub portion and being moreover curved from end to end and in a direction transverse to their side faces whereby to impart to said blades a similar curvature transversely of their bodies.

7. A fan including in combination a pair of blade assemblies each formed of a single sheet of resilient and flexible material and comprising'a pair of blades connected by an integral central portion, said assemblies being disposed with their central portions overlying each other, a hub formed with a plurality of curved slits, such central portions being disposed within said hub and the blades of the different assemblies being disposed one within each of said slits and adjacent each other, and relatively narrow strips of substantially rigid material applied to the base portions of said blades and short of the central portions of said assemblies, said strips having a CARL E. MEYERHOEF'ER.

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