US2037440A - Nonmetallic gear, pulley, or the like, and method of producing the same - Google Patents

Description

Patented Apr. 14, 12936- UNITED STATES PATENT OFFICE NONMETALLIC GEAR, PULLEY, OR THE LIKE, AND METHOD OF PRODUCING THE SAME tion of Delaware Application January 17, 1934, Serial No. 706,906

14 Claims.

'Ihis invention relates to an improvement in non-metallic gears, pulleys or the like and more particularly relates to such formed by compression of fabric, felt, paper o-r the like, and a binder. Heretofore gears, pulleys or the like and blanks therefore have been produced by the compression in a mold of elements impregnated with a binder, separate elements being provided for forming the rim and web portions respectively of the gear or pulley, and separate elements or a filling being provided for forming the hub portion in order that the several portions of the gear or pulley would have the proper relative thicknesses.

In such constructions, the rim and web elements have variously comprised fabric, paper, felt and the like impregnated or associated with a binder such as a thermoplastic composition or a thermosetting composition, as a phenolformaldehyde condensation product which becomes insoluble and infusible under Athe influence of heat and pressure. 'I'hus heretofore, for example, the rim elements haveV been of ring or Washer shape or segments thereof, while the web elements have been of disc shape, or the web has been formed from scrap and a filling has been provided for formation of the hub.

In my application Ser. No. 700,542-, filed December 1, 1933, there is described and claimed an improved arrangement whereby the various elements of flexible material to be compressed toform the gear or the like are of such shape as to provide as an integral Whole rim, web and hub forming sections. The form of these elements is such that when they are arranged in apre- .determined fashion there are provided varying radial concentr-ations of material so that when consolidation takes place by the application of pressure and/ or heat, the binder with which they are impregnated or coated will flow and the compression will result in the formation of a gear or other blank having varying thicknesses in a radial direction. In general, the periphery has considerable thickness and inside this there is located a web portion of less thickness. If a hub of the non-metallic material is provided there may be another increase of thickness adjacent the central portion either forming an entirely non-metallic hub, or being adjacent a metallic filler. It is the object of the present invention to provide animproved blank and method of producing the same so as not only to facilitate the process of manufacture, but also provide a somewhat stronger construction. Specifically, in accordance with the invention elements of the type disclosed in my prior application referred to above are integrally connected with each other in a continuous strip which is spiralled ci'rcul-arly within a mold to provide overlapping of the elements. This spiral series of elements is then compressed in conventional fashion to provide the final blank. 'I'he various objects of the present invention will be apparent from the following description read in conjunction with the accom- Fig. 3 is a diagrammatic plan View illustratingV the spiral arrangement of the elements Within a mold; and

Fig. 4 is a sectional view indicating a type of gear or pulley blank formed in accordance with the invention.

There is indicated at 2 -a strip of material as, for example, fabric, paper, felt or the like, either of single thickness or of composite form as, for example, a combination of fabric and paper formed by parallel strips of fabric and paper secured together and forming the rim and web portions respectively, impregnated or coated with a binder which may be of any suitable type as, for example, a thermoplastic or a thermosetting composition, such as a phenol formaldehyde condensation product. It will be understood that this binder may not only be of various suitable types, but may be incorporated or -associated with the flexible material forming the strip in any. suitable fashion so that when compression and/or heating takes place in the molding process it will be substantially uniformly distributed through the material to provide a substantially homogeneous final product.

In accordance with the present invention, cuts 4 are formed in the strip extending from one edge towards the other edge, but not continued all the way through the latter edge, giving rise to an uncut portion along that edge such as indicated at 6. The cuts thus dene structural elements 8 which are integrally joined at 6. By reason of the restricted extent of these portions 6, the various elements may be flexed relatively to each other as indicated in Fig. 2 and as finally indicated in Fig. 3.- A

The strip formed of the various sections integrally united is located spirally within an opening which comprises an outer wall I and an inner post whose specific form depends upon the final product desired. If the gear is to be entirely nonmetallic without having even a metallic liner at the hub portion thereof, then a smooth cylindrical post is provided to define the opening through the blank. If, on the other hand, it is desired to have a metallic liner, then the lower portion of this post is provided by the metallic liner I2 itself, this liner preferably having a serrated outer surface designed to grip the non-metallic body of the blank. To guide the elements located above this liner during the assembly, there is then provided an auxiliary post I4 extending upwardly to the top of the mold.

Whereas in previous arrangements it has been generally necessary to exercise considerable care to insure the proper location of the separate elements, in accordance with the present invention it is only necessary to feed the strip into the mold while either the mold or the feeding means is rotating so that the strip is located within the mold in a spiral form as indicated in Fig. 3. It is only necessary to insure such dimensioning that an overlapping of the successive spirals occurs so as to provide a more or less uniform distribution of material about any circumference Within the inner and outer elements of the mold. Due to lack of perfect uniformity in placing a strip in position, such staggering generally occurs automatically without the exercise of any substantial amount of care.

After the mold is filled by the spiral strip of, for example, the type illustrated, it will be clear that there is a varying radial concentration of material. It will be noted, fo-r example, in the preferred embodiment disclosed herein that there is an overlap of the adjacent elements of the strip at the outer edge of the mold. It will be clear then that adjacent this outer edge there is more than a single thickness of the flexible material provided for each turn of the spiral. On the other hand, it will be evident that halfway between the inner and outer walls of the annular space of the mold there will be very substantially less than an average single thickness of material provided in a single turn of the spiral. There is thus, due to the overlapping and staggered arrangement, a variation in concentration of material between the rim forming portions and the web forming portions. Furthermore, there is again an increase in concentration of the material adjacent the hub. As a result, when compression takes place to finally form the gear or pulley blank there will be provided a thick hub portion I6 surrounding the liner I2, if such liner is provided, a comparatively thin web portion I8, and a thick rim portion 29. By a proper design of the shapes of the elements, and also a proper design of the parts of the mold, there will be secured a substantially uniform density of material in all of the portions of the blank, although the thickness Varies.

In the drawing, there is illustrated a typical arrangement for the production of heavy hub and rim portions and a thin web portion. In such case, the elements take the concavo-convex shape illustrated and the boundaries may be dened by straight cuts arranged at angles as indicated. Instead, of course, the cuts may be smoothly curved instead of being formed angularly as illustrated.

If it is desired to provide, instead of the type of gear or pulley blank shown, some other variation of thickness, then the elements 8 may be cut to correspond and, for example, instead of these elements being connected integrally at one edge of the strip 2, the integral connections may occur somewhere intermediate the edges, cuts being made from both sides inwardly. It will be obvious that these variations may be made by the designer to produce that Varying concentration of material when assembly takes place as will produce the desired product. Preferably, particularly because of convenience in location within the mold, there is provided a continuous strip of elements, a single strip being provided to form the entire spiral stack of elements. Instead, however, only a relatively few of the elements may be connected in a strip, for example, just sufcient to provide one or more turns or even less than a single turn. In any case, the arrangement of the elements is greatly facilitated by reason of their integral connection.

The process of making a gear or pulley blank as described above is also advantageous in that the integral connection adjacent the hub serves to strengthen the final product.

It will be understood that where a blank is referred to it is not to be assumed that such blank may not be a inal product. For example, a satisfactory pulley may be provided solely by molding Without any subsequent turning down of the periphery or machining. Gears may also be provided by the extrusion of all material into properly shaped openings in the outer wall of the mold, which may be partially or completely lled by additional blanks. Such gears, however, are not likely to be as uniform as those provided by cutting teeth in ordinary blanks.

It will be obvious that variations may be made in the invention as indicated above Without departing from the scope thereof as defined in the following claims.

What I claim and desire to protect by Letters Patent is:

1. A strip of non-metallic flexible material including a binder adapted to be consolidated under pressure in the formation of a gear, pulley, or the like, comprising rim and web sections, said strip having cuts extending inwardly from one edge thereof defining a series of elements joined along the opposite edge of the strip and of such form that, when the last named edge is caused to approximately assume a circular form, the elements extend divergently outwardly and by overlap provide varying radial concentrations of material, whereby, upon compression, there may be provided a rim of greater thickness than the web.

2. A strip of non-metallic exible material including a binder adapted to be consolidated under pressure in the formation of a gear, pulley, or the like, comprising rim and web sections, said strip having cuts extending inwardly from one edge thereof defining a series of elements joined along the opposite edge of the strip and of such form that, when the last named edge is caused to approximately assume a circular form, the elements extend divergently outwardly and by overlap provide varying radial concentrations of material, whereby, upon compression, there may be provided a rim of greater thickness than the web, said strip being of such length that, when said last named edge assumes approximately a predetermined circular form, the strip overlaps itself.

3. A strip of non-metallic exible material including a binder adapted to be consolidated under pressure in the formation of a gear, pulley, or the like, comprising rim and web sections, said `strip having cuts extending inwardly from one edge thereof defining a series of elements joined along the opposite edge of the strip and of such form that, when the last named edge is caused to approximately assume a. circular form, the elements extend divergently outwardly and by overlap provide varying radial concentrations of material, whereby, upon compression, there may be provided a rim of greater thickness than the web, portions of adjacent elements of said strip overlapping each other when said last named edge assumes approximately a predetermined circular form.

4. A strip of non-metallic flexible material including a binder adapted to be consolidated under pressure in the formation of a gear, pulley, or the like, comprising rim and web sections, said strip having cuts therein defining a series of elements integrally joined by narrow portions of the material, whereby the elements may be exed relatively to each other into partially overlapping relation and the strip may be circularly arranged for consolidation into a gear or the like.

5. A strip of non-metallic flexible material including a binder adapted to be consolidated under pressure in the formation of a gear, pulley, or the like, comprising rim and web sections, said strip having cuts therein extending from one edge defining a series of elements integrally joined by narrow portions of the material at its opposite edge, whereby the elements may be ilexed relatively to each other into partially overlapped relation and the strip may be spirally arranged for consolidation into a gear or the like.

6. A non-metallic gear, pulley, or the like, comprising a plurality of integrally joined par- .tially overlapped, non-metallic elements and a binder consolidated under pressure, said elements comprising integral rim and web forming sections.

7. A non-metallic gear, pulley, or the like, comprising a plurality of integrally joined partially overlapped, non-metallic elements and a binder consolidated under pressure, said elements comprising integral rim, web, and hub forming sections.

8. A non-metallic gear, pulley, or the like, comprising a plurality of non-metallic elements and a binder consolidated under pressure, said elements being defined by cuts extending inwardly from one edge of a strip of exible material and being joined along the opposite edge of the strip, the associated elements being of such form that when the last named edge is caused to assume a circular form, the elements extend divergently outwardly and by overlap provide varying radial concentrations of material, whereby, upon compression, the rim of the gear or the like has a greater thickness than the web thereof.

9. A non-metallic gear, pulley, or the like, comprising a plurality of non-metallic elements and a binder consolidated under pressure, said elements being dened by cuts extending inwardly from one edge of a strip of exible material and being joined along the opposite edge of the strip, the associated elements being of such form that when the last named edge is caused to assume a circular form, the elements extend divergently outwardly and by overlap provide varying radial concentrations of material, whereby, upon compression, the rim of the gear or the like has a greater thickness than the web thereof, the strip being of such length that, when said last named edge asumes approximately a predetermined circular form, the strip overlaps itself.

10. A non-metallic gear, pulley, or the like, comprising a plurality of non-metallic elements and a binder consolidated under pressure, said elements being defined by cuts extending inwardly from one edge of a strip of flexible material and being joined along the opposite edge of the strip, the associated elements being of such form that when the last named edge is caused to assume a circular form, the elements extend divergently outwardly and by overlap provide varying radial concentrations of material, whereby, upon compression, the rim of the gear or the like has a greater thickness than the web thereof, portions of adjacent elements of said strip overlapping each other when said last named edge assumes approximately a predetermined circular form.

11. A non-metallic gear, pulley, or the like, comprising partially overlapped elements formed by cutting a continuous strip of non-metallic flexible material from one edge and a binder consolidated under pressure.

12. A non-metallic gear, pulley, or the like, comprising a continuous strip of non-metallic flexible material cut on lines extending from one edge of the strip to form elements integrally connected along the opposite edge of the strip and spirally arranged with the elements in partially overlapped relation so as to provide varying radial concentrations of material and a binder consolidated under pressure.

13. The method of making a non-metallic gear, pulley, or the like, which includes cutting a strip of flexible material from one edge to form a plurality of rim and web forming elements integrally connected at the opposite edge of the strip, locating the strip annularly within a mold with the elements respectively in partially overlapped relation and applying compression to the strip so located.

14. The method of making a non-metallic gear, pulley, or the like, which includes cutting

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