US1646242A - Nonmetallic gear - Google Patents

Description

1 1927. Oct E. J. GUAY ET AL NONMETALLIC GEAR Filed Jan. 1926 #0 0 W r n. t

e e t vi A sectional view of a portion of a finished Patented Oct. 18, 1927.

UNITED STATES 1,646,242 PATENT OFFICE.

EMILE J. GUAY, OF SWAMPSCOTT, AND CLARENCE W. MANSUR, F MALDEN, MASSA- CHUSETTS, ASSIGNOBS T0 GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

NONMETALLIC GEAR.

Our invention has for its object to improve the construction of gears and gear material of the above-mentioned type and also to reduce the losses due to wastage of valuable materials.

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

In the drawing which is illustrative of our invention, Fig. 1 is a side view of a rim or a rim member of a gear blank; Flg. 2 1s a sectional view showing how the fabric ribbon is pleated in a plane perpendicularto the axis of the blank; Fig. 3 is aside View on a somewhat enlarged scale also showing the arrangement of the pleats; Fig.4: is a cross section of a rim member; Fig. 5 is a gear, and Fig. 6 shows a'folded over ribbon to compensate for variations in thickness of the inner and outer edges of the rim members.

so a

In carrying out our invention, we employ a relatively narrow ribbon 7 for forming a.

large portion of the rim. The ribbon may be woven as such, or it may be made by cutting a Wide sheet into strips. The latter method has some advantages over the former due to the fact that it is more nearly uniform in thickness due to the absence of tlIu; such a ribbon is wound on edge to form an annulus it will be found that the inner edge will be crim'pedwhile the outer edge is tight. This is due to the fact that whereasthe diameters of the inner and outer. edges are different theamount of fabric or numbers of threads at said ed es is the same. To compensate for this ifi'erence of diameter we closely pleat the ribbon, the depth of the threads which form the selvage edge. 40

pleats being governed by the diameter of.

the blank and the width of the ribbon; To attain the best results the pleats are deeper at the inner edge than at the outer, the amount being governed by the difference of diameter of the two, edges. If the pleats 9, 1926. Serial No. 80,216.

are made uniform the desired result may be obtained by having the pleats overlap at the inner edge. The ribbon may be coated with a binder such as a phenolic condensation product, either before or after pleating, but

as a general thing it is preferable to first coat the ribbon and then pleat it, since by so doing an excess of binder is avoided, it being remembered that the strength and elasticity of the finished product is due to the woven fabric and not to the binder. The

ribbon after being coated with the binder,

and dried in any suitable way, is closely pleated, as indicated at 8 in Fig. 2. In this figure the portions of the pleats are, purposely separated so that the arrangement can be clearly seen. It will be noted that'by thispleating each layer of the ribbon as ap-- plied to the rim member comprises three thicknesses of fabric. The ribbon should be closely pleated so as to avoid the formation of pockets containing binder alone as. distinguished from fibers and a binder in the finished product. After the ribbon is pleated it is wound edgewise around a drum or equivalent support to form a helix such as indicated in Fig. 1, the plane of each turn of the helix and hence .of the pl'eatsthemselves being perpendicular to the axis thereof. This perpendicular arrangement is important because when the teeth are cut in the blank the edges of the numerous la ers,

as distinguished from the side face 0 the fabric, will be presented to the teeth of the companion meshing gear. For gears intended for relatively heavy duty, it is preferable to make the pleats slightly deeper at the inner edge than at the outer edge, as indicated by the dotted lines 9 in Fig. 3, or if the pleats be uniform to overlap them at the inner edge. The purpose of this is to avoid as far as possible open spaces or pockets between adjacent pleats in the same turn of thehelix. If there are such spaces or pockets the will be filled with binder in the heating an pressing operations and for some classes of gears this is not particularly objectionable but for heavy duty gears it is desirable to have fibers of the fabric as uniformly arranged as possible and to avoid even very The helix should be so woundthat the bends dueto the spreading of the fibers of which the fabric is composed when'subjected to the heavy pressure usedin the final operation.

of the pleats in the difi'erent'layers, turns, or-laminations do not register, i. e., a pear in the same axial plane, but should e .in stag ered or overlapping relation- In other wor s, the bends in-one turn'of the helix should be opposite the first surface of the adjacent turns of pleated ribbon. To accomplish this, the pitch of the pleats should be suchthat a given number of pleats will cover a little more or a little less than the complete circumference of the drum used in the forming operation. The non-register ing arrangement of the pleats is indicated in Fig. 1 where the full lines 10' indicate the bends in the pleats of one layer or turn, and the dotted lines 12 the bends inanother I layer.

It will be evident in using a ribbon of, uniform widthand thickness that when Wound .into'a helix thesame number of fibers will be present at the inner as well as the outer diameter of the ring or turn of the helix and because the diameter at the periphery is greater than at the inner surface or bore of the ring or turn the material in the region ofthe bore will be slightly thicker, measured -axia-lly, than in the region of the periphery.

In some gears this does not make any difl'erence but in others it does. Where it is de- "sired to make a rim" of uniform thickness anddensity of fibers, inserts maybe em vployed and preferab1y* made from woven 1 fabric, although other materials having suit able characteristics may be used. In Fig.

- tween rim members, between parts of a memthe members.

= pieces of woven ber, or they may be applied to the sides of The helically wound rim member may be applied directly to a metal center or to a center composed of textile binder-treated material. Thelatter may be composed of fabric, or moldable materials,-or a combination of both. In Fig. 5

15 shown a center or webx15 composed of binder-treated wovenfabric made in the formof disks, se ments or' other forms. Preferably, someo the disks 16 -will extend from between thev rings or rim members to the hub thus tying them to the hub elements while'others .will serve to -cover the sidefaces of therim members andialso-to tie them to,

the web and hub. The web maybe keyed directly to thesupporting shaft or a metal hub such as 17 may be employed.

We have found that bodies made of pleated fabric and held under compression by a suitable binder'are' muchharder to split inthe plane of the laminations than "when made of plain flatpieces piled fiatwise. 'We attribute this chiefly to the fact that the adjacent surfaces considered as a whole are not so smooth and uniform as is, the case with plain, flat pieces, and hence the binder tions. There is also a certain interlocking of the laminations which further resists-the tendency to split. A' blank constructed as described has the great advantage that the more securely unites or bonds the laminathreads or fibers, either thejwarp orwoof in the rim are substantially parallel to-each [other and. in planes perpendicular to the axis and hence a largepercenta ge of them extend radially'of the finished-teeth from the root to the pointthereof. i

It '.will be evident by utilizing ribbons as distinguished from disks, segments or other out forms, that a "cry great saving is effected in the high grade, expensive materials emareused for anchoring purposes or as fillers, any tr1mm1ngs or scraps resulting-from the cutting operatlons may be utilized in the 'webor hub portion of the'blank.

ployed. -When woven fabric disks or pieces After the parts have been prepared as re-i I viously described, they are sub ected to eat to soften the binderand then to ressure to compress the fibers,'the final actlon of heat and pressure causing the binder to harden and retain thefibers in their compressed state thereby forming a uniformly ri 'id structure. In this particular we may 01- low the established practice. -In forming gearblanks it ispreferable to employ molds of a single piece of ribbon but in somencases .it will be satisfactory to use several such iameter. I y 'Insteadof makmgfthe center portion, i. e. the hub andv web of woven fabric we may ieces, especially when the gear is of large make it of a moldablecomposition compris- .ing textile material fibersand a hinder or othenucomp'ositionin fact which Will of an aiford a firm supportfor. the rim and which will readily unite therewith when subjected shaped to conform to the finished blanks. f Preferably each rim member or unit is made to the temperaturesand. pressures used in forming said IlIIl. "Where-such a composition center is provided it maybe covered on.

both sides withv sheets of fabric which not only increases the strength of the blank but im roves .its appearance.

at we claim as new and desire to secure by Letters Patent of the United States 1. Ablank of the; character described. hav

ing at least a portion of its rim comprising woven fabric arranged in layers, said fabric being pleated, the pleats increasing in depth from the periphery inwardly, inserts which compensate for difference in thickness of different parts of the rim due to the form of the pleats, and a binder which holds the fabric in a compressed state.

2. A blank of the character described comprisin a hub portion, fabric disks which extend from the hub portion to the periphcry of the blank, bodies of fabric located between the disks and forming with them the rim, each of said bodies comprising layers of fabric which are pleated over their entire surface, the pleats contacting with one another, the side pleats also contacting with the disks, and a'binder which holds the disks and bodies in a rigid structure.

3. A blank of the character described comprising rings which form the major portion of the rim and which are composedof relatively narrow strips of woven and pleated fabric, said strips standing e'dgewise with respect to the web of the blank with the pleats perpendicular to the axis and in firm contact with one another, a woven fabric disk located between the rings and extending into the web to form an anchor, other.

anchoring, disks which form the side faces of the blank including the web, and extend to the hub thereof, a fabric filling for the space defined by the outside disks, rim and hub, and a'binder which unites the various parts over their entire surface and holds the fibers thereof in a compressed state to form a rigid structure.

In witness whereof, we have hereunto set our hands this 7th day of January, 1926.

EMILE J. GUAY. CLARENCE w. mason.

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