US2899715A

US2899715A - meyer

Info

Publication number: US2899715A
Authority: US
Publication date: 1959-08-18
Anticipated expiration: 1976-08-18

Description

8, 1959 D. A. MEYER TEXTILE RUB APRON Filed Feb. 2a. 1956 OINVENTOR. DANIEL' A. M

% ATTORNEY v EYER 2,899,715 Patented Aug. 18, 1959- TEXTILE RUB APRON Daniel A. Meyer, Dayton, Ohio, assignor to The Dayton Rubber Company, a corporation of Ohio Application February 28, 1956, Serial No. 568,205

9 Claims. (Cl. 19-153) The present invention relates to textile aprons and particularly to rub aprons which are employed in carding or condensing machines wherein a ribbon or strip of loosely associated, generally aligned fibers such as slivers or rovings are condensed or compacted preparatory to being-spun into yarn.

In conventional textile machinery of the type employing aprons according to this invention, there are normally provided pairs of spaced rollers about which the aprons in the form of closed bands are positioned whereby the aprons become elongated and present flat broadside surfaces. The rollers and the aprons thereon are so positioned that the broadside surface of one apron will be in closely spaced parallel relation to a comparable surface of a second apron; Opposite rotary motion is imparted to the rollers about which the respective aprons operate so that the opposed, closely spaced broadside surfaces of the two aprons will travel in the same linear direction. The space between the opposed broadside surfaces is such that if a roving or sliver is placed between these broadside surfaces it will be conveyed endwise across the distance between the spaced rollers about which the aprons are operating and will at the same time be confined on its top and bottom by the apron surfaces.

In addition to the endwise travel thus provided the fibrous strands, it is necessary in accordance with the requirements of the condensing and rubbing operation that a transverse motion likewise be imparted to the aprons whereby the loose strands may be rolled and condensed to provide the desired yarn of circular cross section. In order to provide this oscillating transverse motion of the rub aprons, it is the common practice to equip the condensing machinery with eccentric devices capable of providing transversely oscillating motion to the rollers about which one or both of the opposed apron surfaces are operating.

In view of the bi-directional operation of the aprons as outlined above, and the necessity for positioning the aprons to establish a rubbing contact with the fiber strand therebetween, the rubbing or fiber-contacting broadside surfaces of the apron are subjected to considerable friction and abrasive wear. In order to obtain a uniform rubbing and condensation of the fibrous strand, it is of course necessary that a substantially uniform rubbing surface be provided; and, toward this end, the surface of the apron is normally ground to a smooth finish. While such surface is thus found suitable for preferred condensation of the fibrous strands, it is an unfortunate and disadvantageous consequence of such smoothly ground surfaces that, if satisfactory contact is to be made with the fibers to provide the desired rubbing, the opposed rubbing surfaces must be brought so close together as to come in contact with each other whereupon the frictional and wearing efiects resulting from the bi-directional motion of such surfaces are greatly enhanced. At the same time an undesirable degree of smoothness or slicking up may result.

' A necessary adjunct of this necessity for close contact between the companion surfaces of two or more rub aprons operating upon the same fibrous strand is the generation of heat resulting from the friction between the surfaces and the strands. This heat is unsatisfactory in that it increases the deterioration of the material of which the aprons are formed; and in many cases, particularly with regard to fibers of synthetic materials now popularly employed in the textile industry, it has an adverse effect on the yarn being produced.

While certain beginnings have been undertaken in they prior art to provide the necessary rubbing action without at the same time requiring the close contiguity of the opposed surfaces of a pair of aprons, such beginnings have proven unsatisfactory in that at least parts of the aprons were still subjected to the same wearing causes. Providing the rubbing surface with ribs or other projections, for example, proved additionally unsatisfactory in that the depressions or voids between the ribs resulted in such surface irregularities as to completely destroy the ability of the aprons to provide a uniform rubbing action and a uniformly condensed fiber. Since none of these expedients for relieving the frictional wearing effects proved successful, the art has accepted the same and has, for the sake of a uniformly condensed yarn, resorted to a smoothly ground substantially uniform rub apron surface, despite the attendant disadvantages as mentioned above.

It is accordingly an object of the present invention to provide an improved textile apron capable of operating satisfactorily without excessive frictional wear.

it is a further object of the present invention to provide a textile rub apron capable ofsatisfactorily condensing a loose strand of fibrous material without having its rubbing surface in direct contact with such surface of, a-

It is still another object of the present invention to provide a rub apron capable of achieving the above objectives while at the same time providing a uniform rubbing action resulting in a uniformly condensed fibrous strand.

Applicant has discovered that the foregoing and other ob ects which will be apparent from a reading of the following disclosure all resulting in a greatly improved textile apron may be achieved by providing the working or rubbing surface thereof with a resilient, elastomeric material having embedded therein a plurality of finely divided frangible granular particles.

The resilient material forming the base or matrix of the rubbing face of the apron is preferably of an elastomeric nature such as the vulcanizable natural rubber and synthetic rubber compositions including the butadieneacrylic nitrile copolymers, the polychloroprenes, the butadiene-styrene copolymers, the polysulphides and the like. In general, the oil-resistant elastomers such as polychloroprene and butadiene-acrylic nitrile copolymers are preferred.

The particles to be dispersed throughout the resilient matrix are preferably of a silica-containing or siliceous material having a hardness ranging from approximately seven to approximately eight on the Mohs scale of hardness such that they are classifiable as frangible. Where such particles of a frangible nature are employed and when, as is the custom in the manufacture of rub aprons for textile machinery, the facing or rubbing sur are placed in operation, the particles in or near the rubbing surface will be broken and removed therefrom leaving a plurality of small cavities opening thereon. Since the particles employed according to this invention are of a frangible nature, it follows that substantially all of the particles exposed to the working surface will be broken and removed before the apron is placed in operation. It also follows that the form and shape of the particles employed are of utmost importance to the improved results obtainable by the present invention insofar as the shape of the cavities which remain to influence the working characteristics of the apron is entirely dependent upon the shape of the particles which occupied such cavities before the particles themselves were broken and the fragments thereof removed. In this regard applicant has discovered that improved condensing of loose fiber strands may be obtained if the particles incorporated in the facing layer and the cavities resulting from the evacuation of such particles from the layer are orbiculate or substantially spherical or spheroidal. It will be understood of course that, as the surface is worn away, those cavities which open thereon will also diminish in volume and will assume the shape of spheroidal segments rather than complete spheroids.

While frangible silica or silicate particles of generally spherical or spheroidal configuration such as glass beads, sand granules and the like have been found capable of producing improved results according to this invention, it has been found further that especially improved and particularly satisfactory results may be achieved if the particle incorporated in the facing surface of the apron is a hollow particle such that upon the fragmentation thereof a plurality of shell-like particles resembling those of a broken eggshell will result. Although, as stated above, all of the particles of the broken fragments which are actually exposed to the surface will be removed from such surface before the apron is placed in operation, it has been found that the hollow particles capable of providing such shell-like fragments having acurved cross section do result in an improved rubbing apron. It is theorized that those particles near the rubbing surface but not actually exposed thereto may be broken in the grinding process or during the operation of the apron and that the small individual shell-like fragments of curved cross section themselves impart a peculiar property to the facing surface which renders it capable of improved rubbing action. A further advantage of this type of particle is the greater frangibility of the hollow shell-like particle so that the particles are more readily disrupted prior to as well as during use to leave the desired cavities in the surface. Thus, as the apron wears, the surface structure will be maintained.

'One specific particle that has been found especially satisfactory for use in this regard is a unicellular thinwalled hollow substantially spherical particle formed by the fusion and expansion of finely ground clay. Such hollow spherical particles of fused and expanded clay are obtained in the manner set forth in the Patent No. 2,676,892, dated April 27, 1954, which issued to I. D. McLaughlin. According to this patent, the particles are manufactured by feeding a finely ground and screened clay into the top of a vertical furnace through which it falls and, while so doing, passes through a gas-air flame whereupon it becomes heated to a temperature above 2700 F. causing it to become fused and expanded into a hollow ceramic particle and whereafter it cools during the remainder of its fall.

The invention thus generally described may be more clearly understood in connection with the following detailed description of one preferred embodiment thereof in connection with the appended drawings.

In the drawings:

Figure 1 is a view in perspective of a rub apron according to the present invention and Qi 1 I out which the same operates in a conventional carding or condensing machine.

Figure 2 is a view in perspective partially broken away and in partial cross section of a preferred particle for incorporation in the matrix composition of an apron of the type shown in Figure 1.

Figure 3 is an enlarged cross-sectional view of one preferred form of textile rubbing apron according to the present invention.

Referring now to Figure 1, the rub apron designated generally by the numeral 10 is shown to be in the form of an endless band which is stretched or elongated and positioned about the rollers 11 and

11a having shafts

12 and 12a which may be rotatably mounted. In order that the apron may be caused to travel as a result of the rotation of the rollers 11 and 11a, the inner surface 13 thereof is provided with suitable friction material such as rubber or synthetic rubber. At the same time, in order that the apron will continue to operate and will not stretch, the same is preferably reinforced at or near the base 13 by a non-extensible material such as cord or fabric. It will be observed that the rollers 11 and 11a are provided with a groove 14 or other guiding means located near the margin of the apron to be placed therearound to register with projecting lugs or bosses such as 15 affixed to the base 13 of the apron. It will be understood that as the rollers are placed in rotation and the apron turns thereabout, the latter will be guided by virtue of the registry of its projections 15 with the roller groove 14. Other expedients for guiding the apron around the rollers are well known to the art and any such may be substituted for that shown in Figure 1 without departing from the spirit of this invention. In addition to the guiding effect of the projections 15 and the grooves 14 on the rollers to register therewith, such projections and grooves or other guiding means also result in imparting to the apron any transversely oscillating motion which is imparted to the rollers 11 and 11:: by the condensing or rubbing machinery. By virtue of the above-described inter-relationship between the rollers 11 and 11a and the apron 10, a bi-directional motion is imparted to the apron and particularly to the rubbing surface 16 thereof which spans the distance between the rollers 11 and 11a and which is so positioned that it will operate in closely spaced parallel relation to a similar rubbing surface of a second apron operating about a like pair of rollers. The bi-directional action referred to involves, as stated above, a linear travel between the spaced rollers 11 and 11a and a transverse motion corresponding to the axial oscillation of the rollers. The linear motion provides for the travel through and across the rubbing surface 16 while the oscillatory motion provides for the condensing and rolling of the loose fibrous strands into condensed and substantially uniform fibrous strands of circular cross section.

Referring now to Figures 2 and 3, it will be seen that the apron referred to above in connection with Figure 1 comprises a base 17 composed of one or morelayers 18 of inextensible material such as fabric which may be impregnated or coated with a friction material such as rubber, synthetic rubber or like elastomeric composition. As explained above, the function of this base is to provide dimensional stability to the apron so that it will not become enlarged and lose its desired contact with the rotating rollers 11 and 11a of Figure 1. The base 17 at the marginal portions of the apron is shown to be reinforced by additional layers 19 of inex'tensible material preferably rubberized fabric to receive the anchoring or fastening means forv the rivets or guide buttons such as shown at 15 in Figure .1. In the preferred embodiment shown in Figure 3 the guide buttons 20 are shown to be affixed to the apron by means of rivets 21, the heads of which are recessed below the rubbing surface 22 so as not to interfere.

with the continuity thereof. It will be observed furterial to be worked upon.

portion of the apron.

ther that the rivets pass through the marginal portion of the apron at points where it is reinforced by the additional marginal fabric reinforcing strips 19. As stated above, the guide buttons 20 are provided at points spaced along the circumference of the apron in a position to register with a groove or similar guide means provided on the rollers so that the apron will be guided over the rollers and will react positively to any transverse or axial oscillation thereof. The components thus far described in connection with Figure 3 are those which are conventionally employed in the rub apron art and form no part of the present invention. For the improvement provided hereby attention is directed to the facing material 23 positioned outwardly of the base 17 to provide that portion of the apron which actually performs the rubbing operation.

-As explained above, this facing material is preferably of a resilient nature and the various rubbers including natural rubber and the synthetic rubbers such as the polychloroprenes, the butadiene-acrylic nitrile copolymers, the butadiene-styrene copolymers, the polysulphides and the like have been found suitable for this purpose. One particular rubber or elastomeric composition found especially desirable for use in rub aprons of the type described is an oil-resistant synthetic rubber compound consisting of the following ingredients in the indicated proportions by weight:

Parts by weight Chloroprene polymer (neoprene) 100 During or immediately following the preparation of the rubber-like compound set forth above on a mixing mill or in an internal mixer, the particles of the type considered in the present disclosure may be added in proportions of from 20 to 150 parts by weight based upon 100 parts by weight of the synthetic rubber copolymer. The particles are dispersed through and admixed with the elastomeric matrix material on the conventional mixing equipment employed in the rubber and plastics industry.

A preferred particle for incorporation in the elastomeric matrix material of the facing or rubbing layer of an apron according to the present invention is shown in Figure 2' to be in the form of a hollow ceramic sphere of fused and expanded finely ground clay. The hollow interior 24b of the particle is surrounded by the frangible thin wall 24a of siliceous material which may be readily broken into curved fragments. For the greatest improvement in aprons according to this invention the particles should range in size from 0.001 inch in diameter to 0.090 inch in diameter, the exact size and amount of particles to be employed depending upon the size and characteristics of the textile ma- It has been found, for example, that an apron performing with optimum results on cotton fibers will not be quite as satisfactory on wool or rayon fibers and vice versa.

Textile rub aprons according to this invention are preferably built upon a cylindrical mandrel having an outside circumference corresponding to the desired inside circumference of the apron. The fabric layers 18 having been first impregnated or skim coated with a rubber or elastomeric composition are wound upon the mandrel to form the inextensible, roller-contacting base During the building up of this base the additional edge-reinforcing fabric strips such as 19 are also wound upon the mandrel. Upon the base so constructed is wound the facing layer 23 of the above-described matrix material having admixed therewith and dispersed therein the particles according to the teachings hereof. While this facing layer may be made of several continuously wound layers of relatively thin material, it has been found desirable, because of the presence of the frangible particles therein, to employ just one Winding of the facing material which is of a thickness corresponding to the thickness of the facing layer desired in the finished apron. All of the layers will of course be suitably cemented and spliced in any of several manners well known and understood by the artisan.

Where vulcanizable materials are employed for the facing layer and/or in association with the materials forming the base of the apron, the apron, once constructed, is subjected to vulcanizing conditions of heat and pressure. A convenient means of so doing is to wrap the apron While still on the mandrel with a narrow fabric tape known as a crosswrap which is usually wetted and wound under tension so that it will apply pressure to the vulcanizable material. The cross wrapped apron is then placed in a steam or water vulcanizer where it is subjected to vulcanizing temperatures. In the case of the preferred compound set forth above, the apron is vulcanized in hot water under a pressure of pounds per square inch at a temperature of 275 F. for three and one-half hours where the apron is between one-eighth and one-quarter of an inch thick. Once the apron is vulcanized and allowed to cool, the crosswrap is removed and the facing or rubbing surface is ground with a traversing grinding wheel to provide a smooth cylindrical surface.

It is during this grinding of the rubbing face of the apron' that the particles exposed or becoming exposed thereto are broken into fragments which are removed by blowing, wiping or simply revolving the apron at a rapid rate. Because of the peculiar nature of the particles employed according to this invention, a novel assortment of cavities varying in size as well as in shape is provided on the rubbing surface; and these various shapes and sizes are believed to be primarily responsible for the improved rubbing properties of the apron. For example, even though only a small part of a particle is exposed to the surface and the grinding thereof, the particle will be broken into fragments which may be easily removed from the cavity previously filled by the particle. The result of such prompt breakage is a cavity of the shape designated by number 27 in Figure 3. While this cavity is open to the facing surface 22, it is nonetheless substantially spherical; and its opening upon the surface is in the form of a circle of a diameter considerably less than the interior diameter of the cavity and is surrounded by the resilient fin or lip 28. If the grinding of the surface is continued the lip 28 will of course be removed and a small crater such as 25 or a semi-spherical cavity such as 26 will remain. Since the particles are uniformly distributed throughout the entire thickness of the facing layer or at least near the intended surface thereof, the particles will be exposed in varying degrees to whatever surface is finally established by the grinding and a plurality of cavities according to each of the above descriptions will open upon such surface.

Although the precise manner in which the aprons according to this invention operate to provide the improved results is not definitely known, it has been found that such aprons will provide a satisfactory rubbing and condensation of loose fibrous strands Without having to be positioned so closely to companion aprons as to create undesirable friction between the rubbing surfaces thereof. Consequently, the aprons do not become heated, do not develop slick or smooth spots and do not become prematurely worn or unusable.

It should be understgod that the specific examples and embodiments of the present invention as described above have been employed for the purpose of illustration only and do notlimit the scope of the invention as defined and set forth in the following claims.

I claim:

1. An apron for textile processing units comprising an inner roller-contacting surface and an outer facing layer composed of an elastomeric matrix material having a plurality of rounded frangible siliceous particles dispersed therein, the rubbing surface of said facing layer being substantially free of such particles and having a plurality of voids in the form of at least segments of said particles opening thereon and conforming to the cavities remaining in said surface after the removal of said particles there from.

. 2. An apron for textile processing units comprising an inner roller-contacting surface and an outer facing com- I posed of an elastomeric matrix material having a plurality of substantially spherical fused siliceous particles dispersed therein, the rubbing surface of said facing being substantially free of such particles and having a plurality of voids in the form of at least segments of said particles opening thereon and conforming to the cavities remaining in said surface upon the removal of said particles therefrom.

3. A textile processing apron comprising an outer facing layer composed of an elastomeric matrix material having a plurality of hollow frangible siliceous particles dispersed therein, the rubbing surface of said facing layer being substantially free of such particles and having a plurality of voids in the form of at least segments of said particles opening thereon and conforming to the cavities remaining in said surface after the removal of said particles therefrom.

4. A textile processing apron comprising an outer facing layer composed of an elastomeric matrix material having a plurality of hollow fused siliceous particles dispersed therein, the rubbing surface of said facing layer being substantially free of such particles and having a plurality of voids in the form of at least segments of said particles opening thereon and conforming to the cavities remaining in said surface after the removal of said particles therefrom.

g 5. A textile processing apron having an outer facing layer comprising an elastomeric matrix material having a plurality of thin-walled h'ollow frangible particles diS= persed therein; the surface of said layer being substam tially free of such particles and having a plurality of voids in the form of at least segments of said particles opening thereon and conforming to the cavities remaining in said surface after the removal of said particles therefrom v I 6 A textile rub apron comprising a substantially inextensible roller-contacting surface and an outer fibercontacting and rubbing surface composed of a layer of an oil-resistant synthetic rubber composition having a plurality of cellular particles offused and expanded finely ground clay dispersed therein, said rubbing surface being substantially free of such particles and having a plurality of voids in the form of at least segments of said particles opening thereon and conforming in shape to the cavities remaining in said rubbing surface after the removal.

of said particles therefrom.

7. A textile rub apron according to claim 6 wherein said oil-resistant synthetic rubber composition is a compound of a chloroprene polymer. l

8. A textile rub apron according to claim 7 wherein said particles are present in the proportion of from 20 to 150 parts by weight to parts by weight of the chloroprene polymer.

9. A textile rub apron according to claim 8 wherein said particles range in outside diameter from 0.001 inch to 0.090 inch.

References Cited in the file of this patent UNITED STATES PATENTS 2,569,546 Treue Oct. 2, 1951 2,621,375 Bacon et al. Dec. 16,1952

2,676,892 McLaughlin Apr. 27, 1954 2,685,109 Balkin et al. Aug. 3, 1954 2,766,800 Rockolf Oct. 16, 1956 FOREIGN PATENTS 764,663 France Mar. 12, 1934