US2377316A

US2377316A - Long draft apron

Info

Publication number: US2377316A
Application number: US523408A
Authority: US
Inventors: Bruce R Billmeyer
Original assignee: Armstrong Cork Co
Current assignee: Armstrong World Industries Inc
Priority date: 1944-02-22
Filing date: 1944-02-22
Publication date: 1945-06-05
Anticipated expiration: 1962-06-05

Description

June 5, 1945. Q BlLLMEYER 2,377,316

LONG DRAFT APRON Filed Feb. 22, 1944 Patented June 5, 1945 none mun mos Bruce R. Blllineyer, Lancaster, Pm, assignor to Armstrong Cork Company. Lancaster, Pa., a corporation of Pennsylvania Application February 22, 1944, Serial No. 523,408

7 Claims.

This application is a continuation in part of my copending application, Serial No. 404,781, filed July 31, 1941, and relates to a. long draft apron including a layer formed of a plurality of convolutions of twine, a strengthening and reinforcing fabric layer disposed exteriorly of said twine layer and a wear-resistant facing of synthetic rubber. The term "twine is used herein to denote strings, threads, cords, twists, small ropes, spun yarns, or the like of cotton, flax, silk, wool, nylon, glass fibers, rayon, or some other fibrous substance capable of being wound in tubular form.

The chief object of my invention is to produce a long draft apron which possesses the features of flexibility, frictional surface characteristics reapron whch is substantially inextensible radially and which possesses a seamless, oil-resistant wearing surface including synthetic rubber.

This invention relates to a long draft apron for use in fiber drawing which comprises an inner,

tubular, wear, resistant body, a tubular body of twine placed thereon,a strengthening and reinforcing fabric layer disposed exteriorly of said twine body, and a wear-resistant facing, said members being securely attached to one another.

The attached drawing illustrates a preferred embodiment of my invention, in which Figure 1 is a view in elevation of my long draft apron, partially broken away to disclose the foundation;

Figure 2 is a diagrammatic view of the Casa- V blancas system of long drafting including the long draft apron of my invention;

Figure 3 is a diagrammatic view illustrating a method of forming the tubular twine foundation; and

Figures 4 and 5 are views in elevation similar to Figure 1, illustrating modified forms of my invention.

Referring to the drawing, there is shown in Figure l a long draft apron designated generally at 2. The apron 2 comprises a base foundation 3 of tubular form, a strengthening and reinforclog layer 4 of fabrc thereover. a wear-resistant disposed over and integrally united with the other members of the apron. Preferably. a joining coating I is disposed exteriorly of the fabric 4 to secure the facing thereto, although. if desired, the inner surface of the facing may be rendered tacky or adhesive by the application of solvent to secure the facing to the fabric.

The foundation 3, preferably, is composed of a single length of twine in wound helically to form a tube. If desired, a plurality of pieces of twine may be wound in one layer'to form a multiple threaded tube; in such case, the true pitch or distance between consecutive convolutions of the same piece of twine is greater than the distance between corresponding points in any two successive convolutions. The convolutions may be placed in abutting relationship although, if desired, they may be spaced apart a distance not greater than the thickness of the twine; such abutting or slightly spaced apart relationship of the convolutions'is designated herein by the term "substantially abutting." The twine may be composed of any natural or synthetic fiber of suitable strength for the purpose intended and cotton, silk, wool, rayon, flax, nylon, or glass fibers are examples of satisfactory materials for my purpose. A typical example of satisfactory twine for this purpose is a cotton cord, size #16. four-ply, ten twists to the inch.

In Figure 3, I have illustrated diagrammatically a method of making the foundation. There is shown a lathe 9 of usual type adapted to receive a mandrel ll about which the twine 3a is wound or wrapped. A twine holder ll contains a roll of twine which passes therefrom through an eyelet l! to the mandrel Ill. The holder II is mounted on a carriage ll actuated by a lead screw it connected by suitable gearing (not shown) with the lathe actuating mechanism. The twine holder I I is movable longitudinally of the mandrel II and, preferably, is moved forward-a distance equal to the thickness or diameter of the twine being wound as each convolution is wound so that the adjacent convoluticns abut or are under some degree of tension. Even slight tension embeds the twine Ia to some extent in the inner layer 5.

In the manufacture of the foundation, the mandrel I! is coated with a layer of any suitable mold lubricant such as "Aquarex D" or a suitable soap solution to facilitate removal oi the finished tube or apron. The wear-resistant layer or coating 5 is then applied to the mandrel III. An end of the twine la is then secured to the mandrel and the lathe 9 and holder li actuated to wind the twine helically about the mandrel it. Only slight tension need be placed on the twine to ensure satisfactory winding about, the mandrel. The'convolutions are wound in abutting or, preferably, slightly spaced relationship to form the helical tube. The maximum space between con- Jolutions should be no greater than the thickness of the twine for best results and the convolutions are embedded to some extent in layer 5. The convolutlons are wound with a slight inclination in either direction, toward the right as shown in Figure 3, so that the angles formed by the convolutions with a line drawn axially through the tube fall within the range of 80-90, and preferably, the inclination is as close to 90" as possible. It is desirable that such angles be kept at a maximum to ensure that the foundation of the apron is substantially inextensible radially.

The joining coating 8 is then formed from the inner layer by the application of solvent thereto and brushed over the twine, or a separate coating is applied to the wound tube dependent upon whether the convolutions are spaced apart or are abutting. The strengthening and reinforcing fabric layer 4 is then disposed about the tube. Preferably, such fabric layer 4 is composed of a fabric strip helically wound of opposite hand to the convolutions of twine forming the helical tube although it will be understood it may be a single sheet disposed about the foundation 3' or a fabric tube drawn thereover. Preferably, an adhesive coating or layer 8 is then brushed on the fabric and the assembly is in condition to receive the facing I. It will be understood in stead of a coating brushed on the fabric, the inner surface of the facing I may be softened by the application of solvent to render it tacky and this in effect forms an adhesive coating disposed between the facing and the fabric reinforcement.

Preferably, facing I is composed of an extruded. seamless tube of tough, oil and wear-resistant synthetic rubber. It will be understood, of course, any of layers or coatings 5, 6, and 8 may be dispensed with or, if desired, may be omitted. The tubular facing I is inflated and disposed over the assembly formed as described above and the combination is wrapped with wet fabrictape in order to obtain proper engagement of the wearing surface with the base. It is then vulcanized by placing the article in an open steam vulcanizer and applying steam for a period sufficient to cure the mass and to integrally unite the facing, tubular foundation, fabric reinforcement, and coatings; for example, minutes at 300 F. will be generally satisfactory to obtain the required degree of vulcanization when synthetic rubbers. such as "Hycar 0. R.," "Neoprene, or Thiokol are employed. The article is then removed from the mandrel and the surface is ground or buffed to a desired diameter. to desired length for use as long draft aprons,

The wear-resistant tubular facing 6 may be formed of a suitable synthetic rubber composition as shown in the following formula:

Parts by weight Hycar O. R 100.0 Anti-oxidant 1.5 Softeners 21.5 Stearic acid 1.5 Accelerator 1.5 Reinforcing pigment 80.0 Zinc oxide 5.0 sulfur 1.5

This mixture is suitably milled. Thereafter, it is fed to an extrusion machine of the screw type well known to those in the art and a hollow tubular body of desired size is produced adapted to serve as the wearing surface of the long draft apron. If desired, this composition may be calendered to form a thin sheet which is disposed about The tubing is then severed the wound tube and vulcanized to form a satisfactory seamless wearing surface.

The layers or coatings 5, Ii, and 8 may, be formed of the above composition in sheet or tubular form or dissolved in a suitable solvent, such as methyl ethyl ketone, cyclohexanone, chlorobenzene, chlorotoluene, butyl acetate, or amyl acetate. I have found a coating including 0.8 pound of Hycar" to each gallon of solvent is of satisfactory consistency to bebrushed in application.

In the above composition "Hycar" is a synthetic rubber of the type known as a polymerized butadiene acrylic nitrile copolymer. Other synthetic rubbers may, of course, be employed in forming the wearing surface and layers or coatings, such as Thiokol (olefine polysulfide), Neoprene (polymerized chloroprene), Koroseal (plasticized polyvinyl chloride), or similar copolymers'contalning a high content of chloride, such as polyvinyl chloride-acetate copolymers or the like. Any of the materials of this character which possesses high resistance to oil, extreme flexibility and the characteristics of being extremely resistant to cracking upon continued flexing over long periods of time may be substituted. Rubber may be used in some instances where the service does not require a high degree of oil resistance. The method employed in forming the aprons may be varied depending upon the type of synthetic rubber employed; for example, Koroseal does not require vulcanization and aprons having wearing surfaces thereof need not be vulcanized.

In the above described composition, any suitable anti-oxidants may be used and "Neozone A,.' Agerite Resin D," Aminox," are examples of satisfactory materials. As softeners, I may use tricresyl phosphate, paraflin, dibutyl phthalate, pine tar, cumar, triacetin or the like. ators are well known in the art and mercaptobenzothiazole, tetramethylthiuramdisulfide. diphenylguanidine, zinc butylxanthate, or combinations thereof, for example, may be used. The

reinforcing pigments and fillers included in this composition may include any of various grades of carbon black, 'whitings, clays or the like such as 'I'hermax, P-33, Gastex, Kalite," Kalvan," etc. Zinc oxide is used in the composition primarily as an activator for the accelerators. Stearic acid is used as a plasticizer and aids in vulcanization. Sulfur, of course, is the vulcanizing agent. The ingredients and the amounts used may be varied as desired depending upon the properties required in the completed apron.

In Figure 2, I have illustrated diagrammatically the so-called Casablancas system of long drafting including my apron; it will be understood, of course, my aprons may be used satisfactorily in other long drafting systems such as that known as the Saco-Lowell Roth system. The Casablan cas system comprises a series of positively driven bottom rolls l5, l6, and I1 and a plurality of top rolls IE, IS, and I1; rolls l5 and II are rotated by frictional contact with the bottom.

rolls l5 and H. The top rolls are weighted to apply pressure to the fibers. Aprons l8 and II are provided, apron I8 extending around bottom roll l6 and a guide bar l9 while apron l8 encircles idler roll l6 and a guide bar I9, being rotated by friction developed between the contacting surfaces of the aprons i8 and I8. In this system, there is generally a short draft between the rolls [1, I1, and the r011s'l6, l6 while rolls I5, ii are usually rotated with a surface speed 6 to 30 times that of the rolls I1, I1.

In Figure 4, I have illustrated a modified form Accelerof my invention in which the convolutions of twine forming the helical tube are spaced. In Figure 5, I have illustrated a modified form generally similar to that shown in Figure 1 except that coating 6 disposed between the twine tube 3 and the fabric reinforcement l is omitted.

My invention comprises a long draft apron ineluding a wearing surface which is seamless. tough, flexible, oil resistant and which may be ground to a smooth, true surface of uniform dimensions. The foundation is substantially inextensible radially so that the apron cannot stretch thus materially increasing its life in service. The

apron is economical, simply made, and'does not require large capital expenditure or'investment in stocks necessary for manufacture.

While I have described and illustrated a preferred embodiment of my invention, it will be understood my invention is not so limited since it may be otherwise embodied within the scope of the following claims.

I claim:

l. A long draft apron for use in fiber drawing comprising a tubular body of twine disposed in the form of a helix, a strengthening and reinforcing fabric layer disposed exteriorly of said body, and a wear-resistant facing secured thereto.

2. A long draft apron according to claim 1 in which said facing includes as an essential ingredient a synthetic rubber chosen from the group consisting of a polymerized butadiene acrylic nitrile copolymer, 8. plasticize'd polyvinyl chloride. a plasticized polyvinyl chloride-acetate copolymer, an olefin polysulfide, and a polymerized chloroprene.

3.- A long draft apron foruse in fiber drawing CERTIFICATE OF CORRECT ION.

Patent No. 2,577,5 6.

comprising a tubular body composed of a plurality of convolutions of twine disposed insubstantially abutting relationship and extending in the same direction, a strengthening and reinforcing fabric layer disposed exteriorly of said body composed of a helically wound fabric strip of opposit hand to said convolutions, and a wear-resistant, seamless facing of synthetic rubber secured to said body.

4. A long draft apron for use in fiber drawing which comprises an inner, tubular, wear-resistant layer, a tubular body of twine thereover, a strengthening and reinforcing fabric layer dis posed exteriorly of said twine body, and a wearresistant facing, said elements being securely attached to one another.

5. A long draft apron according to claim 4 in which the tubular body of twine comprises spaced convolutions disposed on the form of a helix.

6. A long draft apron for use in fiber drawing which comprises an inner. tubular, wear-resistant layer, a tubular body of twine comprising spaced convolutions disposed in the form of a helix placed over said inner layer, a strengthening and reinforcing fabric layer disposed exteriorly of said twine body and secured to the twine convolutions and the inner, wear-resistant body where it appears between the spaced convolutions by an adhesive layer, and a wear-resistant facing. said elements being securely attached to one another. 7. A long draft apron according to claim 6 in which an adhesive layer is disposed over said strengthening and reinforcing fabric layer and secures the wear-resistant facing thereto.

BRUCE R. BILLNIEYER.

June 5. 9%-

BHUGE R. BILLMEYER.

It is hereby certified'that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, sec-' 0nd column, line 19,c1aim 5, for "on" read -in---- and that the said Lettors Patent should be read with this correction therein that the same may conform ,to the record of the 'case in the Patent Office.

Signed and sealed this 11th day of September, A. D. 19

(Seal) Leslie Frazer First Assistant Commissioner of Patents.

of my invention in which the convolutions of twine forming the helical tube are spaced. In Figure 5, I have illustrated a modified form generally similar to that shown in Figure 1 except that coating 6 disposed between the twine tube 3 and the fabric reinforcement l is omitted.