US2568913A - Detachable fan hub and blades structure - Google Patents

Description

Sept. 25, 1951 D DETACHABLE FAN HUB AND BLADES STRUCTURE .Filed May 5, 1949 ml 2 Y N IA/ m a? K n Patented Sept. 25,1951

j UNITED srArss .PATENT OFFICE I 'DETACI-IAB-LE FAN HUB AND BLADES STRUCTURE- Khattar Ead, Brooklyn, N. YQ Application May'3, 1949, Serial No. 91,055

My invention relates to air circulating fans, the principal object thereof being to provide a fan having resilient blades and being adapted to be attached easily, quickly, and without the use of any tools as well as without the application of any considerable amount of skill to a piece of lineshafting, to the armature of an electric motor, or the like, to ventilate and circulate air in any place where machines are located and are driven by shafting. The invention applies particularly to power driven sewing machines located in garment workrooms which are frequently poorly ventilated.

Another object of the present invention is the provision of a device of the character described which consists entirely of soft, bendable material, thus eliminating the danger of injury or damage by the rotating, unprotected fan, which could occur if the fan were made partially or entirely of metal or of any other-hard material.

Still another object of the present invention is the provision of a device of the character described which will adjust the pitch of the fan blades automatically to an angle to the axis of rotation of the fan in accordance with the speed of rotation, so as to attain always an efiicient pitch and a substantial flow of air irrespective of the number of revolutions per minute carried out by the axis.

A further object of the present invention is the provision of a device of the character described which will fit shafts of various diameters, so that only one size of fan has to be manufactured for a large number of shaft sizes.

Still a further object of the present invention is the provision of a device of the character described which is comparatively light in weight, and of a very simple construction, so that it can be manufactured and sold at a very reasonable price.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claims, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

In the accompanying drawings the preferred forms of the invention have been shown.

In said drawings:

Figure 1 is a side elevation, partially shown in vertical section, of a preferred embodiment of my invention; and

2Claims. (cilia-1913):... 1.

Fig. 2 is a front view of the same.

Similar reference characters refer to similar parts throughout the several views.

In the drawing the numeral I denotes a cylindrical body of bendable material having an open longitudinal section 4 which extends over its entire length. Two or more fan blades 2 of bendable material radiate from the center portion of the body I, and are made as a unit therewith as shown, or are secured thereto by vulcanizing or in any other suitable manner. The material of which the parts I and 2 are made is either rubber or resilient plastic material or any other bendable and preferably soft substance. Thus one and the same body I can be attached to shafts of different diameters or even to shafts which are square, triangular, rectangular, polygonal or otherwise shaped in cross-section. The end portions of the body I have at their outer side annular grooves 3, which are engaged by straps 5 having buckles 6 at one end and perforations in the opposite end I, or by endless rubber bands or straps (not shown), or the like, for securing the body I to a shaft 8.

While the grooves 3 and the straps 5 can be close to the blades 2, so that the body I may be comparatively short, I have found that a comparatively long body I of rubber or other elastic material with the straps at its ends will result in an automatic adjustment of the pitch of the fan blades in accordance with the speed of rotation of the shaft 8. If the latter rotates at a low speed, the center portion of the elastic body I rests firmly on the periphery of the shaft 8, while-upon an increase of the speed-the centrifugal forces will create a tension which widens the diameter of the center portion of body I thus decreasing the angle of the fan blades to the axis of rotation.

Since certain changes may be made in the above article and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which as a matter of language might be said to fall therebetween.

Having thus fully described my said invention, what I claim as new and desire to secure by Letters Patent in the United States is:

1. A detachable fan hub and blades structure comprising a cylindrical longitudinal body of resilient material having an open longitudinal section which extends over its entire length and being provided at its outer side with annular grooves, fan blades made as a unit with said body radiating from a portion thereof which is located between said grooves, and straps engaging said grooves and being adapted for securing said body-to-a shaft.

2. A device of the character described comprising a longitudinal cylindrical body of bend-v able material having an open longitudinal section which extends over its entire length and provided with annular grooves at the outer sides of its end portions, bendable portions-shaped as fan blades radiating from the portioning said body, and straps engaging said grooves and being adapted for firmly securing said body to 4 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 335,640 Simmons Feb. 9, 1886 750,904 Smith Feb. 2, 1904 8291. e ew 190'! 1,360,516 Franseen Nov, 30, 1920 2,035,081 Lower Mar. 24, 1936 2,040,504 Siegel May 12, 1936 2,144,326, Callaghan Jan. 17, 1939 2,144,860 Thorp Jan. 24, 1939 2,212,072 Newnham Aug. 20; 1940 2390,299 Gutkin Dec. 4, 1945 2,461,965 lgal ikow Feb. 15, 1949

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