US2229982A - Nonmetallic gear wheel blank and method of making same - Google Patents

Description

Jan. 28,1941. c W.MANS'UR 'Y'ETAL 2229,982

NONMETALLII'C EAR WHEEL BLAmk AND METHOD OF MAKING SAME Filed Aug. 19, 1938 lliiln Inventors:

Grady H. Salter,

The T Attorney.

Clarence \N. Mansur,

Patented Jan. 28, 1941 STA NONMETALLIC GEAR EL BLANK AND METHOD OF G SAME Clarence W. Man'sur, Maiden, and Grady H.

Salter, Lynn, Masa, assignors to General Electric Company, a corporation of New York Application August 19, 1938, Serial No. 225,750

, 2 Claims.

- an artificial resin such as a phenolic condensation product which is convertible to -an-infusible insoluble state by the application of heat and pressure. a

' An object of our invention is to provide an improved construction of gear wheels or gear wheel blanks of this type wherein the rim and web are molded directly to the hub without the use of a preformed element, such'as a preformed rim or web. Another object of our invention is to provide an improved and economical method of manufacturing such a gear wheel or gear wheel blank which permits the use of a lower grade of fabric in the web than is used in the rim yet produces a strong satisfactory product in which the parts are firmly bonded together in the finished structure which is free from-any tendency to develop cracksin the web.

For the consideration of what we believe to be novel and our invention, attention is directed to the following description and the claims appended thereto.

In the drawing, Fig. 1 isa face view of a strip of woven nonmetallic material,v such as cotton duck, and illustrates. an initial step in carrying out our invention; Fig. 2 is a perspective view showing the manner in which a strip, as shown in Fig. 1,, is spirally wound edgewise to form a member to be used as the rim of the gear wheel or gear wheel blank; Fig. 3 is a face view of a strip of woven nonmetallic material, such as cotton duck, and illustrates another step in carrying out our invention; Fig. 4 is a perspective view showing the manner, in which a' strip, as shown in Fig. 2, is wound circumferentially into an'annulus or ring to be used as the web of the gearwheel or gear wheel blank; Fig. 5 shows the parts of a mold with the members, shown in Figs. 2 and 4, together with a hub, assembled therein prior to molding; Fig. 6 is a sectional View of a part of the completed gear wheel blank;

and Fig. l is a perspective .view of the completed blank made in accordance tion.

In carrying out our invention, we first provide a strip of woven fabric I, such as a suitable grade of cotton duck having projections, 2, on one edge, the fabric being treated with an adhesive, for example an artificial resin such as phenolic condensation product and being of suflicient width to form the rim-of a gear wheel blank. The strip may be formed by taking a pieceof with our invenmaterial twice the width of the rim and perforating it longitudinally along an irregular line at the center of the strip, as shown at 2'. The strip is also slit along itsouter edges for a short distance toward the center line, as indicated at 4. These slits 'need, not be uniform in length. Preferably, also, the center perforated line is not completely perforated. Theparts which are not perforated are indicated diagrammatically at 5 and occur at spaced intervals along the center line. The strip is then bent lengthwise on itself to form a strip of double thickness, the strip being provided with the projections 2. The strip is then wound edgewise after the manner shown in Fig. 2 thereby providing a ring member 3 to be used as the rim of the gear wheel blank. The projections 2 are shown as being rounded but they" may be of any other suitable shape. The strip may be treated with the adhesive either before or after it is formed. Preferably, we treat a width of cotton duck, and cut it into strips of the width, shown in Fig. 1. before proceeding as outlined above.

Theweb of the gear is formed by taking a strip of woven fabric B-of suitable width to form the web, which-fabric may be of a lower or cheaper grade than 'the fabric used in. making the rim, is treated with an adhesive, for example, an artiiicial resin, such as a phenolic condensation product. The strip 6 may be formed taking a piece of material of appropriate width and slitting it at spaced intervals from the edges toward the center line of the strip, the slits I being formed in staggered relation, as shown in Fig. 3. As in the case of the rim, the strip may be treated before or after it is formed. We then'wind the strip 6 circumferentially into an annulus or ring 8, as shown in Fig. 4, to provide a structure of suitable thickness to form the web of the gear wheel blankin the finished structure; the inner diameter being of a width to receive the hub.

The members, shown in Figs. 2 and 4, are placed in asuitable mold, as indicated at 9, which may form part of a hydraulic press and are subjected to heat and pressure to consolidate the structure and cure the adhesive. The method of molding material of this type to form gear wheel blanks is well known in the art and does not require a detailed description. The structure is molded under sufficient pressure and at the required temperature to effect the desired consolidation of the structure and the curing of the adhesive. After molding, the structure is removed from the mold. A cross section of the product is shown in Fig. 6 while Fig. '7 shows the finished blank in permaterial at the periphery of the 'web member to flow into the spaces and among the projections of the rim member. Because of the fact that the web structure contains the, series of slits in the fabric,- as described above, a complete and homogeneous consolidation in the press takes place and a uniform molding is, obtained. The s1its,

moreover, permit the stresses and strains developed in the pressing operation to be more uniformly distributed and result in a gear wheel or gear wheel blank which is completely free from any tendency to develop cracks in the web, especially along the web portions adjacent the inner periphery of the rim. The particular web structure also facilitates the embedding therein under pressure of the hub, which may be a metallic hub. It will, therefore, be apparent that the particular web structure containing the slits at spaced intervals is an important feature of our invention.

It .will be seen that the present invention provides'a method and a construction wherein an improved gear wheel or gear wheel blank is obtained without the use of any preforms. Also our invention enables the use of a cheaper fabric for the web portion because the resulting structure is completely consolidated and is a homogeneous ring first formed.

product, which is strong and free from cracking stresses and strains which have a tendency to develop ingear wheels of this type which do not utilize the particular web structure described.

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

l. A gear wheel blank formed from a rim comprising a strip of woven fabric wound edgewise on itself and-united with an adhesive, the inner edge of the strip having spaced projections and the outer edge of the strip having slits at spaced intervals, a web formed from a strip of .woven fabric wound circumferentially in annular -'form and united with an adhesive, the edges of the strip having spaced slits cut from the edge to the central line of the strip, a hub in the "center 01 the wound web and united thereto, the rim and webwbeing intimately united to each other.

- 2. The method of manufacturing a nonmetallic gear wheel blank which comprises winding edgewise a strip of woven fabric having projections along one edge and slits along the other edge to form a ring with the projections on the inside.

' circumferentially winding in annular form a strip of woven fabric having staggered spaced slits cut from each edge toward the center line of the strip, placing a hub in the central opening of the circumferentially wound strip and molding under heat and pressure the hub and the circumferentially wound strip inthe central portion of the cinnamon w. MANSUR. GRADY n. SALTER.

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