US1433730A - Generator stream lining - Google Patents

Description

W. H- KEIVIPTON, B. J. GUDGE, AND F. P. LAUFFER.

GENERATOR STREAM LINING.

APPLICATION FILED JULY 25.1918.

ELABSJFSQ. Pmmd (m. 31, 1922.

Patented @et. El, IQZZ.

WILLARD H. KEMPTON AND BENJAMIN 3'.

GUDGE, OF WILKINSBURG, AND FRANK P. LAUFJEER, OF IRWIN, PENNSYLVANIA, ASSIGNORS T0 WESTINGHOUSE ELECTRIC 2: MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

GENERATOR STREAM LINING.

Application filed July 25, 1918. Serial No. 246,768.

Vania, and FRANK P. LAUFFER, a citizen ofthe United States, and a resident of Irwin, in the county of Allegheny and State of Penn sylvania, have invented a new and useful Improvement in Generator Stream Linings, of which the following is a specification. Our invention relates to stream-lined cas- 1ng s and more particularly to stream-lined caslngs or tail-pieces for the generators of aircraft wireless installations, and it has for its object the provision of a laminated, mold-- ed body, of hollow stream-line design, which may be readily applied to, or removed from, the casing proper of the generator and which, as a rule, will partially enclose the generator casing.

' In this connection, a still further object which we have in view is the provision of a stream-lined casing of the above described character which shall be unusually light, although strong, and which will not be effected by moisture, oils, or acids and one which is not inflammable. 5

A still further object which we have in mlnd is the provision of a novel means of uilding up the body of the casing, from sheets of suitably-impregnated fibrous material, in such manner that the built-up body, consisting of a plurality of sheets or layers of such material in superimposed relation, may be positioned in a mold and there be suitably treated to harden the impregnating binder and to give proper shape and finish to the resultant stream-lined casing.

We prefer, in practising our invention, to be able to employ fabric sheets, Woven in the usual manner, paper or sheets of cotton batting. For this reason, another object which we wish to accomplish is the development of a suitable pattern for. cutting the sheet material from a flat sheet in such manner that it ma be assembled smoothly and evenly in the desired stream-line shape, either by assembling it about the core ofa mold or about a form of suitable character.

ennsylvania, BEN-- We have found, from practice, that the above mentioned object may be accomplished by cutting the several sheets, constltuting the body of the casing, in such manner that each sheet includes one continuous marginal edge portion or band from one side of which a plurality of tapering pointed streamers project, the bands in the assembled article making up the larger open end of the casing and the streamers being drawn together, edge to edge, to form the tapering end or point of the stream-lining.

Although various methods of holding the assembled streamers, of the successive laminations' of. sheet material, may be devised and employed, we have found that a convenient method is to provide a relatively small, properly shaped wooden block to form a support for the smaller end or point of the casing in order that the several streamers may be tacked, or otherwise secured, to the block and be so held in place throughout the various steps of assemblage and during the positioning of the assembled body upon its core and within a suitable mold.

In the drawings, in which similar refer ence numerals indicate corresponding parts throughout, Fig. 1 .is a side elevation of a generator, such as is employed in aircraft wireless installations, showing our improved stream-lined casing or tail-piece applied; Fig. 2 is a fragmentary plan of a sheet cut to proper shape for use in building the easing; Fig. 3' is aside elevation of the finished casing; Fig. 4 is a fragmentary axial section showing the smaller end of the casing, together with the reinforcing Wooden block and theadjacent portion of a form used in assembling the casing; Fig. 5 is a corresponding view showing a modfied form of construction.

Primarily, our invention resides in the construction of a hollow casing or tail-piece for wireless generators by forming a properly stream-lined,'ho1low, laminated body of a suitable fibrous sheet material impregnated with a binder. Various fibrous sheet mate rials may be employed, such as a closely matted calendered material as paper, a woven fabric, such as duck, or a loosely matted spinnable fibrous sheet material, such as cotton batting. If deemed advisable, various materials may be employed and, in any event, any one of a number of impregnating materials may be used. Impregnating materials suitable for the purpose include Shellac, copal, casein, marine glue or a phenolic condensation product, such as bakelite. As

" a rule we prefer the use of bakelite because of the fact that a laminated body impregnated with bakelite may be rendered hard and impervious to water, oils and acids by the application of heat and pressure and for the further reason that the mere molding of such abody, by the application of heat and pressure, provides an extremely smooth and highly polished surface which materially reduces air friction when the body is employed for stream-linings or like purposes.

In Fig. 1 we have conventionally illustrated a generator 1 having its usual casing, the generator being located partly within our improved stream-line casing or tailpiece 2 and partly in advanceof it, as shown. Preferably, that portion of the generator casing which is seated within the larger end of the tail-piece is reduced in diameter to receive such larger end in order that the exterior surfaces of the two may merge smoothly into each other. Screws 3, rivets or other suitable means may be employed for detachably or permanently securing the tail-piece in place. The tail-piece is hollow in construction andmay preferably be circular in cross section, being open at its larger end and tapering to a point at its smaller end, the degree of this taper increasing in abruptness from somewhat to the rear of the larger end to the point of the casing, itself.

Although various means may be employed for fitting suitably impregnated sheets of fibrous material to bring them to the desired shape and to still keep the wall of the tail piece smooth and of uniform thicknem, we prefer to cut, or otherwise form, the sheets employed in the manner illustrated in Fig. 2. To accomplish this, a form of the desired shape and dimensions may first be made and the circumferences of this form, at spaced intervals from end to end, may be measured.

These circumferences may then be divided into an equal number of parts and the parts so obtained may be laid off upon a plain surface to plot the curved lines 4 of Fig. 2. By this means, a pattern is provided-from which sheets of suitably impregnated fibrous material 5 may. be out. Each of these sheets,.

as shown in Fig. 2, includes an uninterrupted marginal edge portion or band 6 and a plurality of streamers 7 projecting laterally from one side of the band 6. These streamers t 7 taper from the band-portion 6 to the ends' of the-streamers which terminate in points, \the side edges of the streamers being slightly curvedfor a reason which will be later apparent. The number of streamers, for any one pattern, is of course dependent upon the dimensions of the stream-lined casing to be formed but should preferably be as small band portions 6 of the various layers or I laminations of sheet material are drawn tightly about the larger end of a suitable form or core, and the streamers of the several bands are laid against such form or core with their points brought together, at the point of the form, in such'a manner that the edges of each streamer engage smoothly against the edges of adjacent streamers, care 4 being taken that the streamers of each successive layer shall break joints with the streamers of adjacent layers.

In order to facilitate this assembling of the several pre-shaped sheets about the form,

we may provide a small wooden block to which the points of the streamers may be secured and which constitutes a permanent part of the finished structure, and construct the form upon which the body is built up, as well as the core upon which it is molded, in a peculiar manner to detachably receive this block and hold it in place.

Such an arrangement is shown in Fig. 4 in which 8 represents the smaller end of a form,

this end being cut away at right angles to the axis of the form to provide a plain surfacedface 9 having a central and preferably cylindrical projection 10. The wooden block 11 has a plain surfaced face 12 for engagement against the face 9 ofthe form and a recess ,13 to snugly receive the projection 10, so that, when the block is applied to the form, it is detachably held in axial alinement with it. This block corresponds in shape to the shape of the smaller end or point of the stream-lined tail-piece, as indicated in Figs. 1 and 3, save that,at its point, it is formed with a shallow recess or depression 7 14 which facilitate centering of the article in a mold and which also rovides an easy means by which a hole may be bored through the block after the casing is finished the form 8, the first sheet of suitably shapedmaterial is wrapped about the form and the ends of its streamers are brought into pos-ition against the block and secured in place by small tacks 15' or other suitable fastening means. Further layers of sheet material are then successively applied until a body of the desired thickness has been formed, the ends of the streamers of the several layers being each secured to the block, the inner layers being preferably tacked to the larger or base portion of the block and the outer layers to the block at positions nearer its point. The free ends of the band portions 6 of the sev- 10 eral layers may be drawn tightly together about the larger end of the form and secured by cross-stitching 16, as shown in Fig. 3,

but, as a rule, we have found that, if care is taken in assembling the laminated body, there is no necessity for stitching the edges of any band except that of the outermost layer together. Instead of using several sheets a single sheet of suitable length may be wound spirally about the form.

After the body has thus been built up or assembled, it may be lifted from the form and placed upon a correspondingly-shaped core and then, together with its core, placed ,in a suitable mold and there .treated to harden and compact it. This treatment or curing may be done in various ways, depending upon the adhesive or impregnating material employed. For instance, if shellac has been employed asthe impregnating material, the body, while in its mold, will be subjected to heat and pressure to soften the shellac and to compress the several impregnated layers making up the body after which the mold will be cooled while the body is still held under pressure, to harden the shellac.

On the other hand, if a phenolic condensation product is employed as a binder, the article willbe subjected to the combined action of heat and pressure while in its mold, the heat bein continued until such time as the binder shall have reached its hard and substantially insoluble and infusible state. This molding, if the mold surfaces be highly polished or somewhat oiled, will insure not only a smooth but a highly polished surface upon the stream-lined tail-piece so that it will offer but little skin friction to the passage of air during its use.

In some instances, particularly upon small tail-pieces or casings of the character illustrated, it may be difficult to assemble the ends of the Streamers accurately and to mold them carefully enough to obtain a strong and neat point.- Under these circumstances,

a slightly different method may be followed,

such as that illustrated in Fig. 5. As there shown, the wooden block 17, corresponding to the block 11, instead of being pointed is "substantially semispherical in outline and e the ends of the streamers are cut a little short and tacked on so' that their ends do not quite come together at a point. With this arrangement, a suitable quantity of any preferred molding composition 18 may be applied to the point of the built-up body just previous to its being positioned in the mold. Such molding com osition may comprise any suitable inert 'ller, such as asbestos, wood-flour, ground duck or the like, impregnated with a suitable adhesive, as a binder, preferably the same adhesive as that employed in impregnating the sheet material. Obviously, under these circumstances, this added molding composition will be pressed into shape when the article is pressed and heated in the mold, and a strong and finished point for the tail-piece will be provided, as a result.

Although we have illustrated and described a stream-lined tail piece for generators of aircraft wireless installations, together with a method for making it, it will be appreciated that, by practising our inven-. tion, possibly with minor changes, it will be possible to make stream-lined casings of various kinds and suited for various purposes and, furthermore, that the same construction may well be carried out in forming the stream-lined front and endcaps of aircraft bodies. Furthermore, the stream-lined casing need not be of a laminated type. For

instance, it may be formed of papier mach, brought to the'proper shape, dried, treated with bakelite or another suitable binder and then molded or otherwise cured.

We, therefore, reserve the right to make stream-lined structures for various purposes and to make such changes in the' methods employed as may be best suited to the c1rcumstances, providing such changes come within the scope of the appended'claims.

WVe claim as our invention:

1. A stream-lined structure comprising a hollow body open at one end and closed at the other end and tapering from its open to its closed end, the body being formed of superimposed layers of fibrous sheet material im pregnated with a binder.

2. A stream-lined structure comprising a hollow body open at one end and closed at the other end and tapering from its open to its closed end, the body being formed of superimposed layers of fibrous sheet material impregnated with a phenolic condensation product as a binder.

3. A stream-lined structure comprising a hollow body open at one end and closed at the other end and tapering from its open to its closed end, the body being formed of superimposed layers of a cloth impregnated with a phenolic condensation product as a binder.

4. A stream-lined structure comprising a hollow body open at one end and closed at the other end and tapering from its open to its closed end, the body being formed of superimposed layers of duck impregnated with a phenolic condensation product.

5. A stream-lined structure comprisin a hollow body open at one endand close at the other and tapering from its open to its closed end, the body being formed of fibrous sheet material impregnated with a binder, said sheet material being slitted.

6. A stream-lined structure comprising a hollow body open at one end and closed at the other and tapering from its open to its closed end, the body being formed of fibrous sheet material impregnated With a binder, said sheet material being out to provide a band and streamers.

7. A stream-lined structure comprising a hollow body open at one end and closed at the other and tapering from its open to its closed end, the body being formed of fibrous sheet material impregnated with a binder,

said sheet material being cut to provide a band and tapered streamers.

8. A'stream-lined structure comprising a hollow body open at one end and closed at the other and tapering from its open to its closedlend, the body being formed of fibrous sheet material impregnatedwith a

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