US2179655A

US2179655A - Drive belt for textile spindles

Info

Publication number: US2179655A
Application number: US255264A
Authority: US
Inventors: Roger W Cutler
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-02-08
Filing date: 1939-02-08
Publication date: 1939-11-14
Anticipated expiration: 1956-11-14

Description

939- R. w. CUTLER 2.179.655

DRIVE BELT FOR TEXTILE SPINDLE'S v Filed Feb. 8, 1939 'z z v vzmmmms inch, and parallel to each other to-within 0.0001 "inch Patented Nov. 14, 1939 UNITED STATES PATENT OFFICE muvn BELT ron. 'rax'rrrn srmnuzs Roger w. Cutler, Boston, Mass. I Application February 8, 1939, Serial No. 255,264

13 Claims. (01.14 231) This invention pertains to endless drive belts or "tapes for spinning or twisting spindles, the

present application being a continuation-in-part -of my copending application for Letters Patent,

Serial No. 190,497, filed February 14, 1938.

Such belts or tapes are commonly made of textile "narrow-ware" material consisting of yarns intercrossed by weaving or braiding to form a flat textile tape having selvage edges. In making the endless spinning belts or tapes" a piece of the textile tape of the proper length is cut off and its ends are overlapped, usually with a lap of from 1 to 2 inches and then these lapped ends are united, for example, by sewing.

As the spindle whorl about which the endless belt or tape" passes is of small diameter, for example ,1 inch, and as the spindle is driven at an exceedingly high angular velocity, for instance from 3,000 to 20,000 revolutions per minute, it follows that the material of the tape is subjected to an enormous number of sharp flexings during even a single day'srun. Tape thickness as herein referred to is the thickness of the selvaged textile material as measured in substantial accordance with the directions given for measuring cloth thickness found on page 12 of the United States Government publication designated CCC-T-191a, April 23, 1937, Federal Standard Stock Catalog. section IV (part 5), Federal Specification for Textiles: General Specifications, Test Methods, reading as follows:

3. Thickness.-

3a. Unless otherwise specified, thicknessshall be measured with the gage and procedure given below.

/ 78b. The gage shall be of the dead-weight type equipped with a dial graduated to read directly to 0.001 inch. The presser foot. shall be circular- "with a diameter of 0.375 inch, plus or minus 0.001 inch. Thepresser foot and moving parts connected therewith shall be weighted so as to apply a total load-of 6 ounces, plusor minus 0.1 ounce (equivalent to a pressure of 324, pounds per sq re inch) to the specimen. The presser foot 9. d anvil surfaces shall be plane to within 0.0001

30. The specimen shall be placed upon the anvil oi the gage, smooth, but without tension The presser foot shall be lowered upon the specimen gradually (without impact), allowed to rest upon it for 10 seconds, and the reading of ,the

dial observed. Similar measurements shall be made at not less than five diflerent places uniformly distributed over the surface of the material, exclusive of the area within one-tenth the width of cloth of either selvage when possible (narrow tapes are measured along the center line) or within 3 yards of either end of a roll or piece. 5 The results of the five or more measurements shall be averaged to obtain the average thickness.

It has heretofore been common to use tape of a thickness exceeding 0.050 inch.

Thin tape made of the cheap short-fiber cot- 10.

ton usually employed in making spinning tapes, tends to stretch and is not strong enough to carry the load for a practical period of time without breaking-it being a prerequisite to the commercial acceptability of spinning tape that it have 'of the cheaper 'grades of yarn, to wit, yarn spunfrom carded short-staple cotton, that is to say, cotton from'% inch to H inch staple length. To obtain requisite strength when using such material, it was necessary to weave it close and firm, such tape, in inch width usually running about 45 yards per pound. Tape 01' a thickness of 0.050

inch and upwards is relatively stiff and inflexible,

and when such a tape is formed into a spinning belt or tape and driven at the requisite linear velocity, it offers subs antial resistance to the bending stress which i suddenly applied as the tape makes contact with the curved periphery of the small spindle whorl. This resistance to sudden bend is partially due to the inertia of the constituent particles of the tape and partially due to the resistance to stretching and compression of the material at its outer and inner surfaces, respectively. This stifiness of the tape absorbs a substantial amount of power, and the reluctance of the tape instantly to follow the curved periphery of the whorl cuts down the actual arc of contact between the tape and whorl and thus decreases the effective grip of the belt, with resultant further loss of effective drive power through slippage. When the ends of the tape are proximately 90% ,of such spinning tapes fail at the junction of the tape proper with this twoply portion. Y

The parts of spinning frames require frequent lubrication and it is common for oil to drop onto the spinning belts or tapes, but the textile material of which such tapes are usually made is inJuriously affected by lubricating oil. Moreover, the hygroscopic character of textile fiber tends to cause ordinary spinning tapes to change in length in accordance with changes in the atmospheric moisture of the spinning room so that even though the tapes may be properly tensioned under one condition, they may become too loose for effective driving when the moisture conditions change.

In accordance with the present invention the endless drive belt or tape" consists of a single ply of selvaged textile narrow-ware material (except that its end portions may be folded or overlapped in forming the Joint) and is thin as compared with the tape heretofore generally used in making such spinning belts; that is to say, it is between 0.020 and 0.038 inch in thickness, preferably. from 0.027 to 0.031 inch thick. This thin tape is pliable and hugs the spindle whorl so closely as to avoid slippage thereby greatly increasing spindle speed and yam'production as compared with prior thicker tapes, for example tapes 0.050 inch thick. Moreover, the great pliability of this thin tape as compared with that of the thinnest practical spinningtape known to have been in commercial use prior to the present invention results in a power saving of '7 to 9 per cent or more. However, in this connection it should be noted that mere reduction in thickness is not sumcient in itself, forif tape of the usual short-fiber cotton were so decreased in thickness, a belt made therefrom would stretch and break much too quickly to be acceptable to the trade.

Accurate thickness measurement of such a ma- ,terial as textile tape requires great skill and the use of high precision instruments. It is very useful to define the tape of the present invention upon a yards per pound" basis, since by measuring a long length, accuracy maybe obtained-even by the unskilled and by the use of usual measur-- ing and weighing devices. Thus, reference is herein made to the number 01' yards per pound, a factor which is a very good index of pliability) as well as to thickness, in indicating the novel characteristics of the improved tape. In this connection it is to be noted that thickness and yards per pound are not necessarily equivalent definitions nor in inverse proportion and that one cannot be converted into the other by any simple formula. This is in part due to the fact that the take-up of the warp varies with the number of picks offilling per inch. For example, in the width, 24/3 warps and wefts, woven 66 ends and 28 picks, give '72 yards per pound of 0.0334" 'thickness, while the same yarns woven 63 ends and 18 picks, gives 96 yards per pound of 0.0337" thickness. Thus although the thickness varies but 0.0003", the yardage varies from 72 to 96 per pound.

'I am aware that others, since my own conception of and experiments with thin tape, have independently made experimental tests of thin spinning tape measuring 100 or more yards per pound for the purpose of showing that power is saved by the use of thin spinning tape, and that such independent tests confirm my own tests in showing a very substantial saving in power,

for instance 14%.

However, even though the power saving resultant from the use of very thin tapes (having a breaking strength of approximately 100 pounds in the inch width) theoretically might Justify the cost of replacing tapes frequently, there is a great reluctance on the part of practical mill men to adopt tape having a substantially shorter life than that of the tapes customarily employed, to wit, from nine to eighteen months. Thus the present invention further contemplates the provision of a thin and flexible tape of a strength and durability acceptable to the user, to wit, a tape which will not appreciably stretch under the conditions of use and which will carry the power load imposed upon it for a period approximating the expected life of usual commercial spinning tape, for example from nine to eighteen months, that is to say, for a period of from 2,000 to 4,000 hours ofactuaLuse. To this end, in accordance with the present invention the tape is made of a strong, stretch-resistant yarn prepared from long fiber or filaments. Combed cotton yarn made from 1 inch staple, Upper Nile Supersak Egyptian cotton or its equivalent is desirable in order to obtain the desired strength and flexibility. Further to reduce stretch of the thin flexible belt, it isadvantageous to use mercerized yarn or tape. As an instance of desirable yarn strength, a yarn of 24/4 cotton-count should have a breaking strength'of single strand Buter break of approximately five and one-half pounds,

- and the woven material in inch width should 200 pounds or more.

have a tensile breaking strength of approximately The invention further contemplates the emendless band, as to ensure high flexibility at the Joint. I

In the accompanying drawing:

Fig. 1 is a perspective view, to small scale, .of a spinning belt or tape made in accordance with the present invention;

Fig. 2 is a fragmentary elevation, partly in vertical section, illustrating a spinning spindle of ordinary type, furnished with a driving "tape or fiatbelt;

Fig. 3 is a longitudinal section, to much larger scale, substantially on the line 3-3 of Fig. 1;

Fig. 4 is a diagrammatic transverse section of a piece of tape, suitable for use in making a spinhint:1 belt having the characteristics herein set Fig. 5 is a view similar to Fig. 4, showing thesigned to embrace the whorl 2 of a spinning spindie 3 in the customary way. Several narrowware" fabrics suitable for use in the manufacture of the novel spinning belt or tape of the present invention are indicated by way of example as follows, with the understanding that according to customary usage in the textile arts the number of ends" referred to in a given fabric construction means the number of warp or longitudinally extending yarns in the entire width of the fabric; picks per inch" means the number of weft, filling or transversely extending yarns in each linear inch of the fabric; an expression such as "24/4 means that four No. 24 yarns (numbered in accordance with the Cotton yarn system of numbering) have been twisted together to make a single thread or ply-yarn; while the term "count means the size of the yarn in accordance with the Cotton yarn system of numbering, wherein thenumber of hanks, each of 840 yards in one pound of the yarn, is the number or count of that particular yarn.

For instance, a inch width of the belt, the textile fabric may be woven with fifty ends of 24/4 cotton-count yarn of a soft twist with thirty picks per inch of 24/4 filling, the woven material being approximately 0.031 inch thick and running from 70 to '15 yards per pound. As a second example, sixty-seven warp ends of 24/3 yarn with 32 picks of 24/3 filling per inch may be used or, as a further example, eighty-three warp ends of /2 yarn may be woven with thirty-six picks per inch of 20/2 iilling,-the resultant material running from 75 to 85 yards per pound. As a further specific example of a very desirable and preferred construction, the warp and filling yarns may both be 24/4 cotton-count. spun from cotton of a minimum staple length of 1 inch and of the quality of Upper Nile Supersak, the yarn having a breaking strength of 5% pounds; the tape being woven with fifty-three warp ends and with twenty-eight picks of filling per inch and having a breaking tensile strength of approximately 280 pounds and an average thickness of approximately 0.031 inch and measuring approximately 70 yards per pound.

The above const ctions relate to a tape of inch'width, but it i to be understood that tapes of other widths will be made in corresponding proportions in accordance with the following basic formula as to increase or decrease in the number of warp ends employed in making fabrics-of corresponding constructions. This basic formula is as follows:

. width of ta then add or subtract the percent figure incre se or decrease to the number of warp threads.

Obtain the percent increase or decrease in Formula I 1. Obtain yards of warp yarn" needed for 10 linear yards of fabric of given width. A. 100 yards'times. sley times number of plies in warp yarn. 3. Add to result 10%; for contraction. C. Sum equals total linear yards warp yarn required. [The sley" refers to the number of threads per inch in the warp; the picks refer to the number of threads per inch in the filling] ,2. Obtain yards of filling yarn needed for 100 linear yards of fabric of given width. A. 100 yards times picks times number of plies in filling yarn times width in inches.

13. Add to result 4% to 5% for contraction. 0. Sum equals total linear yards filling yarn required. 3. Add total warp and total filling yarn (total yarn yardage in linear yards of fabric). 5 4. Divide this total by the yards per pound of the single yarn. Result: number of pounds of yarn for 100 linear yards of fabric. 5. Divide No, i by the number of pounds foundanswer is yards per pound.

To afford ample strength the yarn should be spun from combed cotton of fine, long staple, for example, peeler cotton of not substantially less than 1% inch staple length. In'this connection it is to be noted that "peeler" does not define any particular staple length but refers to a variety of cotton grown in the Lower Mississippi River region, such cotton being of a good average length and of high quality. Any desired weave pattern may beemployed. It is common to use what is known as a herringbone weave, but a basket weave the tape should obviously be appropriate to the dimensions of the spindlewhorl on which it is to be used. 3 While it is not essential to the broader aspects of the invention, it is preferred so to treat the material of the tape as to make it resistant to oil and/or moisture and to prevent it from rolling over upon itself. Thus, for example, the tape may be coated, or preferably impregnated, with, for instance, one ofthe cellulose derivativeai'or instance, cellulose acetate; a synthetic rubber, for

instance of thepolyme'rized ,chloroprene type;

certain oil and water-resistant isomers of natural rubber appropriate for the purpose; certain synthetic resins; or bituminous or asphaltic materials or derivatives thereof. In fact, any suitable substance which does not materially increase the stiffness of the band when applied thereto and which hasthe desired oil and/or water-repellant or resistant characteristics, is desirable for the purpose. However, it is desirable to employ a coating OrJ'impregnating material which is of a thermoplastic type, normally substantially nonsticky but which, due to the frictional heat generated in operation, may become very slightly tacky so as to grip the spindle whorl without substantial slippage, although the tackiness oi the band should not be such as ,to interfere with the cloning and piecing-up operations.

Synthetic resins such asthose of the 1118111! polymerized vinyl halide group mixed with spa propriate plasticizers; for example tricresyl phos-- phate, (among others, those commonly known hinder the trade names Thiokol, Duprene, Korolac,

Koroseal, etc.) are-very desirable as the coating or impregnant materials'as these substances possess in high degree the desired resiliency, resistant to oil and moisture, and th rmoplastic character. y A further novel'and hi y desirable property of synthetic resins of the lass just referred to is that when used for coa ing or impregnating a drive belt or tape for spinning'or twisting spindies, the tapes do not become charged with static in use.

Ordinarily the impregnation or coating of the tape by means of such substances as those-above suggested adds but little to its thickness, but, if desired, when the tape is to be impregnated, or coated, it may initially be made slightly less in thickness than the finished tape to allow for the increase due to impregnating or coating it. Thus, the completed and impregnated tape I (Fig. 5) and the coated tape I (Fig. 6) is shown as approximately 0.031 inch in thickness as compared with the untreated tape l of Fig. 4 which is 0.030 inch thick. As already'noted, the impregnant or coating substance should be of such character as not substantially to increase the stiffness of the tape.-

As an alternative to such impregnation or coating, as above described, or as a preliminary thereto, the tape may be made of mercerized cotton, the mercerlzation being carried out either on the yarn before weaving, or on the woven tape. Either complete or partial mercerization of the material of the tape shrinks it so that thereafter it is substantially non-stretching. Thus the spinning belt or.tape," even though thin and flexible, substantially retains its initial length during a long period of use. Not onlydoes mercerization, whether complete or partial, substantially eliminate subsequent stretch, but it also has some eifect in resisting the injurious action'of oil and moisture. While long staple cotton is desirable as a -material for use in making the tape, it is contemplated that other substances may be employed. Thus, for instance, the tape may be made in whole or in part of long filament syntheticyarn, for example, a cellulose derivative or a synthetic resin yarn; or it may include long fiber elements of'inorganic origin, for example, glass or metal.

In fact, recent developments in the production of spun glass filaments and fabrics woven therefrom show such enormous strength andability to endure oft-repeated flexure, that it may be employed, particularly if impregnated as above sug- ,gested, in making spinning tapes of the minimum thickness above suggested with highly satisfactory results.

In making a belt from the selected material, a piece is cut to the desired length and the ends of this length of material are preferably cut on the bias,-as here illustrated, to V-points as shown at! and 5 in Fig. 1.

These v-points are then doubled over so as to overlap the body of the tape and, if desired, temporarily secured by means of a layer 6 of an oil and waterproof adhesive, for example, such a synthetic rubber as above described. After having lapped these ends 4 and 5 over onto the body of the tape so as to form anchorage portions of double thickness, the lapped ends are permanent- 1y, united to the body of the tape by appropriate fastening means, for example, rows of stitches I. The length of material thus prepared is now ready to have its ends united, andthis is preferably done by the use of a metal-wire belt fastener 8 of a type well known for use inuniting the ends of power belts, such vi'astener'comprising a series of interleaved members 9 and III which are provided with prongs designed t'o'be driven into the folded-overend portions, respectively, of the materiaL and which also comprise loop portions which are so overlapped as to receive a pintle member i i, which may be of metal, rawhide 2,17aess or any other suitable material, thus forming a hinge joint between the folded and thickened ends of the hand. These thickened ends, as will be noted, are substantially double the thickness of the impregnated tape l from which the belt is made, and thus these thickened ends are substantially 0.062 inch thick, which is approximately the minimum to form a secure anchorage for a metallic fastener I of the type described.

It has been observed that at the high linear speeds (27 to 30 miles per hour) at which such belts run, the air tends to lift the extreme end of the tape where it is overlapped to form the joint and thus to increase resistance, but by making the ends of the tape with a V-point, as herein disclosed, this eflect is greatly minimized. Moreover, since by the use of the V-point the area of added thickness at the end of the belt gradually diminishes in width, and 'thus in transverse stiifness, the formation of a sharp bend (which, as above noted, tends to occur at the Junction of the body of the band with its double-over portion). is to a large extent eliminated, and thus there is farless danger of breakage of the belt adjacent to the extreme end of the doubled-over portion than is common.

While in accordance with the present invention a hinge-type metallic fastener 8 is preferred as a means for uniting the ends of the length of the very flexible tape, it is contemplated as within the broad purview of the invention that the thin and flexible tape, such as herein shown, may, if desired, be united substantially as usual by lapping and seaming, but preferably with the overlapped ends cut to V-points, since the advantages of the very flexible tape are in large measure obtained even though the overlap form ,of Joint is stiffer than the joint provided by a fastener such as shown in Fig. 3.

It has been proven by extended experiment that by the use'of the novel spinning tape hereinabove described, for example tape of the order of 0.031 inch thick and running 55 or more yards per pound, it is possible to minimize slippage and thus to increase spindle "speed and to make a substantial saving in power consumption as compared with the tapes heretofore customarily emplayed, and suchimproved operation and saving in power far more than compensates for the increased cost of the thin, strong tape as compared with thick tapes, for instance, tapes of 0.050 inch made from short stapleiiber. In order that the thin tape may notunduly stretch during use, it is preferred to preshrink it as above described, either in the yarn or after fabrication, and it has been discovered that by mercerization of the material of the tape the tendency of the'band to stretch while in useis very muchlessened as compared with/f usual cotton tapes so that a thin and flexible bel made of mercerized tape maintains its initial length and tension even better than the thicke and stiffer cotton tapes of prior use. A further and very important advantage resulting from the present invention is that the, resin-impregnated tape dces not become chargedv gather Bil 1.1m endless textile spinning or twisting belt comprising a single ply or flexible selvaged tape composed of interwoven or interbraided yarns predominantly of cotton, said tape having a thick- 'ing of selvaged tape composed of interbraided or interwoven yarns predominantly of cotton, said tape having a thickness of the order 0! 0.030 inch, and a tensile strength of at least 100 pounds and running from '70 to 100 yards per pound in the inch width and other widths in proportion.

3. An endless textile spinning or twisting belt comprising a.single ply or flexible selvaged tape composed of interwoven or interbraidedyarns oil-cotton spun from fiber of a staple length or at least 1% inches, said tape having a thickness of between 0.024 and 0.031 inch, and a minimum length or 70 yards per pound in the inch width and other widths in proportion, and means fiexibly. uniting the ends oi the tape.

4. An endless textile spinning or twisting belt or acceptable durability for driving spinning and twisting spindles, said belt throughout the major portion, at least, of its length consisting of asingle ply oi selvaged textile tape made of interwoven or interbraided yarns, characterized in that the tape used in making the belt is made from yarns spun from cotton or at least one inch staple length, the belt being 01' a thickness less than 0.037 and more than 0.020 inch and running at least 55 yards per pound in the 5; inch, width and other widths in proportion, and having a tensile strength of at least 180 pounds.

5. Power belting of commercially acceptable strength and durability for driving spinning or twisting spindles and which, in use, forms a flexible endless drive belt, said belting consisting of selvaged single-ply'textile tape made from interwoven yarns, characterized in that the tape is or cotton yarn spun from fiber of at least one inch in staple length, the material of the tape being preshrunken bymercerizatlon, and being or a thickness less than 0.03! and more than 0.020 inch, and running at least55 yards per pound in the inch width and other widths in proportion.

0. Flexible single-ply belting of commercially acceptable strength and durability for driving spinning or twisting spindles and which, in use,

i'orms an endless drive belt, said belting consisting or selvaged textile tape made from interwoven or interbraided yarns, characterized in that the tape has a minimum breaking strength, in

inch width, of at-least 100 pounds, and is or a thickness approximating 0.029 inch, and further characterized in that the tape which forms the belt consists of yarn made from fibers or filaments predominantly or cotton or 1% inches or more in staple length.

7. Flexible power belting designed for driving spinning or twisting spindles consisting at a single ply of flexible, selvaged textile tape, the belting being of acceptable durability for driving spinning or twisting spindles and having a minimum breaking strength of 100 pounds and running more than 55 yards to the pound in the inch width and other widths in proportion, the belting being of a thickness less than 0.037 inch, the belting being substantially non-stretching under the conditions of use, the warp yarns at least being made from fibers or-filaments predominantly of cotton 0! at least one inch in staple length, said ibelting being adapted to be converted into an P endless spinning or twisting belt by severing to proper length and uniting the ends or such length. 8. An endless textile spinning or twisting belt of acceptable strength and durability for driving spinning or twisting spindles, said belt through-" out the major portion, at least, of its length consisting of a single ply of selvaged textile tape made irom interwoven or interbraided yarns, characterized in that the tape which forms the belt is or a thickness from 0.020 to 0.036 inch, and that in the inch width the tape runs more than 55 yards per pound with other-widths in proportion, and further characterized in that the tape which forms the belt consists of yarn spun from combed cotton of at least 1% inches staple length.

9. An endless spinning or twisting belt of acceptable strength and durability for driving spinning or twisting spindles, said belt throughout the major portion at least of its length consisting of a single ply or selvaged textile tape made from interwoven or interbraided yarns, characterized in that the tape which iorms the belt is or a thickness of from 0.020 to 0.036 inch, and that in the inch width it runs at least 60 yards per pound with other widths in proportion, and further characterized in that the tape which forms the belt consists of yarn spun from fibers or filaments predominantly oi? cotton oi! more than 1% inches staple length.

10. Power belting of acceptable durability for driving spinning or twisting spindles when formed into an endless drive belt which, throughout the major portion at least of its length, consists of a single ply or the belting material, said belting material being made from interwoven warp and weft yarns, the warp yarns at least being spun from combed cotton of 1% inches or more staple length, the belting being of a thickness of from 0.020 to 0.036 inch and, in the inch width, having a minimum breaking strength of 180 pounds and running more than 55 yards per pound with other widths in proportion.

11. An endless textile spinning or twisting belt of acceptable durability for driving spinning or twisting spindles, said belt, except adjacent to the point where its ends are joined, consisting of a single ply or selvaged textile tape made from inother widths in proportion, and further charac-- terized in that the tape which forms the belt is substantially'non-stretching under conditions of use and comprises yarn-spun from combed cotton of at least one inch staple length, thereby to impart the requisite strength, and has combined therewith a material which tends to prevent electrical accumulation or lint uponits surface.

12. Flexible power belting designed for driving, spinning or twisting spindles consisting of a single ply oi flexible, selvaged textile tape, the belting being of acceptable durability for driving, spinning or twisting spindles and having a minimum breaking strength or 100 pounds and running more than yards to the pound in the inch .width, and other widths in proportion, the belting being or a thickness less than 0.037 inch and being substantially non-stretching under the conditions of use, the warp yarns at least being made from fibres or filaments predominantly 01 cotton 7 of at least one inch in staple length, said belting having combined therewith a flexible synthetic resin or such a nature as substantially to prevent the belt from becoming charged with static eiectricity when in use, the belting being adapted to be converted into an endless spinning or twisting belt by severing to proper length and uniting the ends of such length.

13. Flexible power belting designed for driving, spinning or twisting spindles consisting of a single ply of flexible, selvaged textile tape, the belting being of acceptable durability for driving, spinning or twisting spindles and having a minimum breaking strength 0! 100 pounds and running more than 55 yards to the point in the inch width, and other widths in proportion, the belting being 01' a thickness less than 0.037 inch and being substantially non-stretching under the conditions of use, the warp and weft yarns at least being made from fibres or filaments predominantly of cotton 0! at least one inch in staple length, said belting being impregnated with resin adapted to be converted into an endless drive belt for spinning or twisting spindles wherein the resin substantially prevents the belt from becoming charged with static .electricit ROGER W. CUTLER.

or the vinyl halide group and