US2882139A - Process of manufacture of buffing elements - Google Patents

Description

April 14, 1959 A. s. ROCK 2,832,139

PROCESS OF MANUFACTURE OF BUFFING ELEMENTS Filed Feb. 12, 1957 v 2 Sheets-Sheet 1 April 14, 1959 A. s. ROCK PROCESS OF MANUFACTURE 0 BUFFING ELEMENTS Filed Feb. 12, 1957 Z'Sheets-Sheet 2 I laavezzi'ofl United States Patent PROCESS OF MANUFACTURE OF BUFFING ELEMENTS Albin S. Rock, East Bridgewater, Mass, assignor to F. L.

& I. C. Codman Company, Rockland, Mass., a corporation of Massachusetts Application February 12, 1957, Serial No. 639,800

1 Claim. (Cl. 51-293) This invention relates to a process for manufacturing bufling elements. It is based on the conception that if an annulus of bufiing material of a certain type is supported by a suitable type of metal center itself capable of being expeditiously and cheaply dismantled without damage to the annulus, then the material salvaged from two such annuli after they have been worn down in depth may be utilized in a further step to produce a single full-sized section substantially identical with the originals.

A well-known type of bufiing element, the so-called rufiied bufi, is made from an effectively continuous ring comprising a strip of' bias fabric wound on itself in the form of a cylinder and comprising a multiplicity of plies. Such a ring is folded on itself along a center line with concomitant compaction of the material adjacent that line, and usually, although in lesser degree, throughout the width of the ring to provide two flat annuli side by side, having pleatings or rufiiings produced incident to its transformation in form. This duplex annulus is mounted on a supporting center of one kind or another.

Such a device is in a sense a bufling wheel and might be used alone, but since it has a relatively narrow face, it usually in practice will be what is termed a section, adapted to be assembled with other sections to form a buffing wheel or cylinder having an external cylindrical working face of comparatively great width.

Such an element wears rapidly in use. In production work a large fraction of the radial depth of the bufiing wheel is worn away in a period measured in hours. If the user has such a use for it, it may be shifted to another job with different demands for a further period of use and wear, but in general, even if so extended, its useful life is short. It cannot be worn away right down to the center. the center in a permanent manner, whether the center is made of fiber board of various kinds or is an expendable metal center and the section is considered as a single use or expendable device. It may have some salvage value, but the parts are not recovered except with considerable labor and in a deteriorated condition unfitting them for new uses comparable to the old.

In accordance with the invention a bufiiing element is utilized having a sheet metal supporting center, an example of which is herein shown and described, the complete assembled bufling element being of such nature that, after predetermined wear, it may be returned to the manufacturer where, because of its construction, it may be dismembered and at least the bufiing material re covered in such unimpaired condition and in such form as to provide material for the making of a buff element substantially identical with the original. The metal center may be considered expendable, although as will appear, salvage and reuse of at least a part thereof may be economically practicable.

The invention will be well understood by reference The bufling material is usually mounted on r 2,882,139 Patented Apr. 14, 19 59 2 to the following drawings, showing by way of example a preferred illustrative embodiment of the invention wherein:

Fig. 1 is a side elevation showing one face of a bufling element including a center which face, merely for differentiation, is here called the obverse face;

Fig. 2 is a fragmentary side elevation showing the opposite or reverse face;

Fig. 3 is an enlarged section on line 3-3 of Fig. 1;

Fig. 4 is a schematic view showing an early step in the manufacture of the element illustrated in Fig. 3;

Fig. 5 illustrates a further stage;

Fig. 6 is a fragmentary section showing a portion of an element asshown in Fig. 3 after the butting material has been worn away for a considerable depth;

Fig. 7 shows the bufiing material as recovered from a worn element as shown in Fig. 6 after dismantling;

Fig. 8 shows two units as illustrated in Fig. 7, joined to provide a cylindrical ring or band, ready for incorporation in a buffing element essentially like that shown in Fig. 3; and

Fig. 9 is a fragmentary view looking radially inwardly of a portion of the outer periphery of the members of the center, slightly separated axially.

Referring now to Figs. 1, 2 and 3 of the drawings, I here show a center, denoted as a whole by the reference letter C, supporting an annulus of bufling material denoted generally by the letter A. The center may be compared to a wheel in that it has a central portion or nave, an intermediate body portion B corresponding to the spokes (or the web of a disc wheel) and a peripheral or rim portion R which supports the annulus A which, in a way, corresponds to the non-metallic tire of a wheel. The buffing material A in the completed element is a generally flat annulus with an internal radius a, an external radius b (that of the completed section) and a depth (b-a) marked 0 on Fig. 1. In the form illustrated in Fig. 3, as it is originally made and supplied to the trade, the annulus consists of two annuli set side by side, each having a number of plies or strata and integrally joined at the inner circumference.

Thus, in accordance with the known practices of the art, a cylindrical band or ring (like a napkin ring) may be formed of a strip of bias fabric having a width 20 wound in a multiplicity of turns to form a ring. This ring is marked A(r) in Fig. 4, the letter r being suggestive of the word ring. The ring A(r) has a radius not only greater than a but, when the buff is to be rufiied at its outer periphery, substantially greater than b. The sides of the ring are folded outwardly along its center line and at the same time the material is compacted circumferentially into pleats or rufiiings so that the radius of the inner circumference of the resulting annuli is reduced to the dimension a, and that of the outer circumference to the dimension b. Such a pro ceeding is not new, but it is emphasized that the material in the present instance is not subjected to any treatment, other than the folding or crumpling, which would be inconsistent with its recovery, substantially undeteriorated, as hereinafter described. Thus, in contrast with many buffs, it is not impregnated with plastic or stiffening material along its inner periphery to consolidate that portion in a solid mass, nor are fasteners used which might aflect the integrity of the material or which could be withdrawn only at prohibitive labor cost and with probable further impairment of that integrity.

In contrast with such practices the annuli when brought to the form shown in Fig. 5 are mechanically held at their inner circumferences and effectively secured by the center C, formed by separate parts which are closed thereon in the manner of clamping jaws, but which may be dismantled readily after use, to release the annuli after they have been worn down to a lesser radius, say one equal to one-half of dimension 0, but otherwise, except for the pleating which may readily be extended and flattened out. practically like. new.

There will next be described the preferred form of sheet metal center C, herein illustrated. It comprises two generally circular parts, obverse 20 and reverse. 22. The reverse section 22 herein comprises the nave portion N with a drawn out sleeve 24 to receive in a supporting shaft the body portion B. having openings at intervals defining between them. the spoke-like members 26, herein eight in number, which are herein stiffened by impressed radial ribs 28. throughout their length and which merge into a short. cylindrical portion 30 which in cooperation with parts. of the obverse. section 20 defines theQbot tom of" an outwardly opening channel to receive the interior circumference of. theannulus-A of. bufling materiah, there. being an. outwardly extending flange. 32, one" of the, flanges ofthe aforesaid channel, at the outer endyof' the part30. The flange 32 at its. outer: margin is. provided with inturnedi spurs 34, preferably parallel to theaxis of rotation.

The obverse member 20 is herein open-centered and comprises a flange 36 forming the opposite side of. the channel and having spurs 38 extending inwardly therefrom, a short cylindrical portion 40 at. the inner side of the flange 36, from which extend ears 42v lying in a cylindrical surface and being adapted to pass through the openings between the spokes 26, being received against the interior of cylindrical part 30 of. the reverse member, and to have their ends bent over on the radial flange 32 of the reverse member as seen in Figs. 2, 3 and'6.

In Fig. 4 the two members of the center are shown separated, positioned centrally within the band A(r). The band A(r) is transformed into the duplex annulus as shown in Fig. 5, the interior radius of which corresponds substantially to the radius, a, of the bottom of the channel which is formed by the cooperation of the two center members as shown in Fig. 5. The two members are then brought together axially tightly to embrace and clamp the annulus and are locked together by turning over the cars 42 on the flange 32 as seen in Figs. 2 and 3. The spurs 34 and 38 enter into the body of buffing material A. These spurs are out of line in the respective twoelementsso as not to interfere with each other. They are preferably triangular in form as seen inFig, 9v and they areof a length to extend at least substantially to and conveniently slightly beyond the center circumference which rufflngs however are in a sense free from one another. In practice the spurs appear to find their way into the interstices of the rufllngs without a laceration of the material itself, except to a negligible amount. Atthe same time, after clamping together of the center forming members 20 and 22, the material is firmly held in its upset or ruffled form by the clamping engagement therewith of two gripping jaws which secure a mechanical interlock to the annulus by means of the spurs, preventing displacement of the bufling material under the stresses occurring in use. It is pointed out that the spurs have,v no rearwardly presented shoulders which on dismantling of the section might catch and lacerate the material, in separating the center forming members from the buffingannuli.

The, two members ofthe center may be separated and the section dismantled by unbending the cars 42 and separating the two members 20 and 22 axially. It would of'course be tedious to pry up the ends of these cars manually with a screwdriver in an individual case, but under production conditions" it is easy, by means Qf a suitable appliance, to exert inward or centripetal force thereon to straighten them out.

The economic advantage of the construction is availed of by the following additional steps of the novel method. The bufi section as originally manufactured may conveniently be marked on its side to indicate a depth equal to about one-half of 0 (some allowance for trimming is provided for in practice). When the annuli are worn down to that mark as indicated in Fig. 6, the user retires the bull from use and returns such. worn down sections to the manufacturer. The center is dismantled and the folded section of reduced depth withdrawn. Temporary means for securing the plies together during handling may be utilized. The duplex annulus as recoveredv from the worn down butt is shown separated in Fig. 7, and is marked A2, the 2 indicating that it is in a second stage as compared to its original state, as illustrated in Fig.-. 5,, for example. The duplex annulus .of Fig. 7 hasa depthequal. to one-half of c and an. interior radius equal to a. It. may be unfolded a'ndthe pleatings or ruflling's extendedto form a cylindrical ring of a width 0 and a radiusv greaterv than b and equal to that of the ring A(r) in Fig. 4. Two such salvaged rings may be set side by side as seen in Fig.8 and joined by an auxiliary ply or narrow band.50 as seen in Fig. 8, thus providing a band with. a width 2c. and a radius greater than I), essentially equivalent to the band A(r) as diagrammed in Fig. 4. Thus the ring shown in Fig. 8 may have the two parts at either side of its center line folded together, outwardly and upwardly in the figure, and the assembly may be circumferentially compacted in the same way as the band A(r) in Fig. 4 and grasped by members 20 and 22 of a center, to provide a new bufling element substantially duplicating that illustrated in Fig. 3. This may be worn down through half its depth. The process then cannot be repeated because we would recover only bands having a widthv of one-fourth of c which could not be utilized in the manner shown. in Fig. 8. The user purchases and wears out two buds of a given size and at a moderate cost, less than that of a new buff, gets another as good as new to wear out.

By way of precaution, to insure the integrity of the element under the conditions. of use, the sheet metal may conveniently be made a. little heavier than that which has hitherto been used in expendable sections. Thus, by way of .example merely and without limitation, in the case. of. a section of' 14 inch diameter, sheet metal .042 inch thickhas. been. used. 1 The economy resulting from the salvage and. reuse of. a. reconstituted section equivalent to. the original. is. such, as to. permit this even the center. is.v scrapped when first removecL. However, the obverse-section 2.0 obviously is recoveredunimpaired. Thereverse section. mayrequire a closer inspection and possibly a reshaping of the. ears 42,.although the metal is such that it would stand several bendings without appreciable weakening. Under particular conditions of course a slight additionallabor. charge could be justified, since the parts are to be used only twice. In any instance the manufacturer will receive back two centers for each reissued bufling element and the dismantling, justified alone by the salvage of. the valuable. buffing material, will also at least supply him. with a marketable supply of clean segregated scrap. Probably it would be pre ferred in any event to use. new centers for original elements asinEig. 5, unless perhaps under emergency conditions in time of war.

As. seeninFigs. 1 and 9 theflauge 22. of. the reverse member may have radial corrugations 44.. The inwardly facing. crests press. into the base of' the adjacent annulus and interlock the same. When. a. number of sections are assembled. to form a wheel of relatively gre-atwidth of face, these corrugationsv provide exteriorly passageways to permit air entering throughout the space between the spokes 26 to pass out betweenthe' sections and keep them cool. The" outwardly facing crests of the corrugaaasanse tions bear on the flat faces of the turned over ears 42 of an adjacent section which ears are in such number as to occupy substantially all the circumterence between the spokes and provide an even bearing for the corruga tions and also serve as spacing elements cooperating therewith, slightly to increase the airway.

As seen in Fig. 9 the inward indentations of the corugations are opposite the roots of the spurs 38 and extend into the bases thereof, stiffeningthe spurs.

Certain features of the metallic center herein described are claimed in application Serial No. 677,053, filed August 8, 1957, that application being a continuation in part of the present application.

I am aware that the process described may be practiced by utilizing elements of physical constructions other than those described, if they have the general relationship and form required to permit the substantially unimpaired recovery of the worn down annuli of bufling material, and the specific disclosure is to be considered in all respects as illustrative and not restrictive, as is in fact clear in several matters from the description itself. Refer ence is to be had to the appended claim to indicate those principles of the invention exemplified by the particular embodiment described and which I desire to secure by Letters Patent.

I claim:

The process which comprises detaching and spreading out into the form of a cylindrical band the fabric from each of two used buffing sections of known type wherein a wide cylindrical band of plied fabric is folded outwardly about its center line and secured in folded position by mechanical gripping jaws clampingly engaging the same in -a radially shallow zone adjacent the fold line, which sections have been worn away to approximately half their radial depth, joining one circumferential edge of each to a circumferential edge of the other by means not substantially increasing the thickness adjacent the line of juncture, folding them outwardly along their line of juncture into side-by-side relationship and securing the joined circumferential portions to a supporting center, thereby to produce a single full-sized section charged throughout its circumference and to a substantial radial depth with bufiing compound.

References Cited in the file of this patent UNITED STATES PATENTS

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