US3283366A

US3283366A - Apparatus for removing a fibrous web from a rotatable surface

Info

Publication number: US3283366A
Application number: US478027A
Authority: US
Inventors: Kalwaites Frank
Original assignee: Johnson and Johnson
Current assignee: Johnson and Johnson
Priority date: 1965-08-02
Filing date: 1965-08-02
Publication date: 1966-11-08
Anticipated expiration: 1983-11-08

Description

Nov. 8, 1966 F. KALWAITES 3,283,366

APPARATUS FOR REMOVING A FIBRCUS WEB FROM A ROTATABLE SURFACE Filed Aug. 2, 1965 4 Sheets-Sheet 1 24 1} /2 i 1 E 4/ 5:2 q

INVENTOR FPAA/K 62; 1144/75:

mmT/W i ATTORNEY F. KALWAITES Nov. 8, 1966 APPARATUS FOR REMOVING A FIBRCUS WEB FROM A ROTATABLE SURFACE Filed Aug. 2, 1965 4 Sheets-Sheet 2 T'lqflh lNVENTOR Few/r K44 1444/72-5 flit m ATTORNEY 1956 F. KALWAITES 3,

APPARATUS FOR REMOVING A FIBROUS WEB FROM A ROTATABLE SURFACE Filed Aug. 2, 1965 4 Sheets-Sheet 5 Q" P f I III/III ,2 y m 7 INVENTOR.

AM flfanmvas BY A ATTORNEY F. KALWAITES Nov. 8, 1966 APPARATUS FOR REMOVING A FIBROUS WEB FROM A RO'I'A'I'ABLE SURFACE Filed Aug. 2, 1965 4 Sheets-Sheet 4 INVENTOR FRANK. KALWAITES BY flXivLlY-b ATTORNEY United States Patent M 3,283,366 APPARATUS FOR REMOVING A FIBROUS WEB FROM A ROTATABLE SURFACE Frank Kalwaites, Somerville, NJ., assignor to Johnson & Johnson, a corporation of New Jersey Filed Aug. 2, 1965, Ser. No. 478,027 6 Claims. (Cl. 19-106) This patent application is a continuation-in-part of my co-pending patent application Serial Number 324,602, filed November 13, 1963, now abandoned, which in turn was a continuation-in-part of my patent application Serial Number 279,949, filed May 13, 1963, now abandoned.

The present invention relates to apparatus and methods for removing fibrous webs from rotating surfaces and more particularly is concerned with apparatus and methods for removing fibrous webs from the rotating dotting cylinder of a textile carding machine.

In the processing of textile-length fibers whereby they are converted from naturally-occurring or syntheticallyprepared, intermatted fibrous masses into relatively uniform fibrous textile materials, such as slivers, rovings and webs which have a generally predominant fiber orientation in the long direction thereof, the individual fibers are initially separated and formed into a fibrous web by means of a textile carding machine. This fibrous web, in which the individual fibers are relatively aligned generally in the long direction of the web, is dotted or removed from the rotating dotfing cylinder of the card usually by a rapidly reciprocating dofiing comb for further processing or handling, as desired or required. This rapidly reciprocating dofiing comb, having a periodic toand-fro movement, is physically limited in its maximum speed and in the number of reciprocations it can make and in most cases is the limiting factor on the speed of the rotating dofling cylinder which, having a rotational movement, normally could have a greater surface linear speed, if it were not so limited by the dofiing comb. Thus, the dofiing comb limits the speed of the textile carding machine and is considered the limiting factor on its capacity or throughput.

Additionally, it has been determined that the reciprocating action of the teeth of the doffing comb, as they rapidly pass to-and-fro through the fibrous Web, strike, rub and brush against the individual fibers, change the predominant fiber orientation thereof, and perform their dotfing function in a generally ineflicient manner.

It is therefore a principal purpose of the present invention to provide apparatus and methods capable of: (1) dofiing or removing fibrous materials from a rotating surface such as the dofiing cylinder of a textile carding machine without limiting its speed, capacity or throughput; and (2) performing such dofiing or fiber-removing function in an efiicient manner without materially changing the predominant fiber orientation of the fibrous Web.

It has been discovered that such a principal purpose may be accomplished by providing a first rotatable surface which is capable of carrying a fibrous web, positioning a second rotatable surface also capable of carrying a fibrous web immediately adjacent to but spaced from said first-mentioned rotatable surface whereby a V-shaped throat having arcuate surfaces leading to a narrowopening is formed between the two rotatable surfaces, and then positioning a stationary but adjustable flexible nip blade in tangential pressing contact with the second rotatable surface and extending away from that second rotatable surface on both sides of the point of tangency therewith, with one relatively short free end of the nip blade extending up into the narrow V-shaped throat formed by the two rotatable surfaces. As a result, the fibrous Web which is carried by the first rotatable surface can be removed 3,283,366 Patented Nov. 8, 1966 ICC therefrom to be carried around the free end of the nip blade into contact with the second rotatable surface to be pressed against such second rotatable surface by the nip blade substantially only at the point of tangency and then to be carried forwardly by the second rotatable surface and delivered for further processing and handling, as desired or required.

Now, inasmuch as only rotating surfaces are involved in such an arrangement and since there is no limiting reciprocat-ing to-and-fro periodic movement, much higher speeds are obtainable whereby increased capacity or throughput is realized. Also, there is no rapid reciprocation of comb teeth to-and-fro through the fibrous web whereby increased doffing efficiency is realized and the predominant fiber orientation is not materially changed.

The fibrous web .or layer which is processed to form the products of this invention may contain natural or synthetic, vegetable, animal or mineral fibers such as cotton, silk, wool, vicuna, mohair, alpaca, flax, ramie, jute, etc.; synthetic or man-made fibers such as the cellulosic fibers, notably cuprammonium, viscose or regenerated cellulose fibers; cross-linked cellulosic fibers such as Corval and Topel; cellulose ester fibers such as cellulose acetate (Celanese) and cellulose tri-acetate (Arnel); the saponified cellulose ester fibers such as Fortisan and Fortisan-36; the polyamide fibers such as nylon 420, nylon 6 (polycaprolactam), nylon 66 (hexamethylene diamine-adipic acid), nylon 610 (hexamethylene diaminesebacic acid), nylon 11 (ll-amino undecanoic acid-Rilsan); protein fibers such as Vicara; halogenated hydrocarbon fibers such as Tefion (polytetrafluoroethylene); hydrocarbon fibers such as polyethylene, polypropylene, polybutadiene and polyisobutylene; polyester fibers such as Kodel and Dacron; vinyl fibers such as Vinyon and saran; dinitrile fibers such as Darvan; nitrile fibers such as Zefran; acrylic fibers such as Dynel, Verel, Orlon, Acrilan, Creslan, etc.; mineral fibers such as glass, metal; etc.

The average lengths of the fibers in the starting fibrous web are of textile length and may vary from about inch or /2 inch up to about 2 /2 inches or more in length,-

depending upon the particular properties and characteristics required or desired in the resulting fibrous web.

If desired, the fibrous layer may have added thereto, by a subsequent processing step, from about 1 or 2 percent by weight up to about percent by Weight but preferably less than about 50 percent by Weight, of fibers other than those of textile length. These other fibers may be of short papermaking length, which extend from about inch in length down to about of an inch or less in length, which shorter fibers normally are not used in conventional methods of producing fibrous webs.

Illustrative of these short papermaking fibers are the natural cellulosic fibers such as woodpulp and wood fibers, cotton linters, cotton hull shaving fibers, mineral fibers such as asbestos, glass, rock wool, etc., or any of the hereinbefore-amentioned natural or synthetic fibers in lengths less than about inch and down to about of an inch or less.

The denier of the individual synthetic fibers referred to above is preferably in the range of the approximate thickness of the natural fibers mentioned and consequently deniers in the range of from about 1 to about 5 are preferred. Where greater opacity or greate covering power is desired, special fiber deniers of down to about or even about /2 may be employed. Where desired, deniers of up to about 5.5, 6, 8, 10, 15, or higher, may be used. The minimum and maximum denier are naturally dictated by the desires or requirements for producing a particular fibrous web, by the machines and methods for producing the same, and so forth.

The weight of the fibrous web or layer of starting material on the dofling cylinder may be varied within relatively wide limits above a predetermined minimum value, depending upon the requirements ofthe intermediate or the final products. A single, thin web of fibers, such as produced by a card and as presented by the dotting cylinder, may have a weight of from about 30 to about 250 or more grains per square yard and may be used in the application of the principles of the present invention. Within the more commercial aspects of the present invention, however, web weights on the doffing cylinder of from about 50 grains per square yard to about 175 grains per square yard are contemplated.

The invention will be more fully understood from the description which follows taken in conjunction with the accompanying drawings in which there are illustrated preferred designs of machines and modes of operation embodying the invention. It is to be understood, however, that the invention is not to be considered limited to the constructions disclosed except as determined by the scope of the appended claims. In the drawings:

, FIGURE 1 is a simplified, fragmentary, schematic view in elevation showing one embodiment of the general principles of operation of the present invention;

FIGURE 2 is an enlarged view of a portion of FIG- URE l, drawn to a much larger scale showing in greater detail certain elements of the present invention;

FIGURE 3 is a simplified, fragmentary, schematic view in elevation showing another embodiment of the general principles of operation of the present invention;

FIGURE 4 is a simplified, fragmentary, schematic view .in elevation showing still another embodiment of the genenal principles of operation of the present'invention; and

FIGURES is a simplified, fragmentary, schematic view in elevation showing a further embodiment of the. general principles of operation of the present invention; and

FIGURE dis a simplified, fragmentary, 'schematic'view in elevation showing a further embodiment of the general principles of operation of the present invention.

In the embodiment of the invention illustrated in FIG- URE 1 ofthe drawing, a conventional textile card is used and comprises a conventional rotatable main'card cylinder (not shown) which is. used to provide for the normal carding of the fibers fed thereto leading generally to a thin sheet of individualized fibers very sparsely spread over the main card cylinder surface in an amount weighing merely a few. grains per square yard. These substantially individualized fibers are then presented to and transferred to a slower moving doffing cylinder rotating on a shaft mounted in bearings secured to the card frame 12.

The dofling cylinder 10 is convent-ional and may be covered with conventional fillets which are continuous stn'ps of narrow card clothing, 1 /2 or 2 inches wide, and long enough to helically wrap around and entirely cover the cylindrical surface of the doffing cylinder. The conventional bent wires penetrate the heavy fabric foundation of the fillet card clothing and protrude therefrom in the usual 'way whereby dolfing and stripping functions are possible. If desired, however, the dofiing cylinder may be covered with conventional metallic card clothing which consists of a steel band with teeth punched-or otherwise formed in one side and usually a thick rib on the other side. This steel band is wound helically around the surface of the cylinder, on edge, so that each coil fits closely against the preceding coil, thus producing a cylindrical surface entirely coveredwith fine saw-tooth points whereby dofiing and stripping functions are possible.

Immediately adjacent the dofling cylinder 10, and approximately at the position where the fibrous web W formed thereon is conventionally removed by the usual reciprocating doffing comb, there is located a cylindrical, rotatable dofiing roll 14 rotating on a shaft 18 also mount- .ed in the card frame 12. This doffing roll 14 has about the same length as the dofiing cylinder 10 but has a much 4. smaller diameter which is in the range of from about 1% inches to about 10 inches, or even larger, but preferably is in the range of from about 3 inches to about 6 inches. Under normal circumstances, it rotates with the same surface linear speed as that of the dofiing cylinder 10.

The dotting roll 14 is so positioned with respect tothe dofiing cylinder 10 and is so spaced therefrom that a V- shaped throat is formed between two rotatable surfaces leading to a relatively narrow opening. This opening or clearance is sufficient to permit rotation of the doffing cylinder 10 without rubbing against the dofiing roll 14. The clearance between the doffing cylinder 10 and the dofiing roll 14 will depend upon many factors such as the type of fibers being processed, the weight of the web being handled, the relative speeds involved, etc. In most cases, this clearance isof the order of from about 4 inch up to about inch, with a preferred range of from about inch up to about A inch.

The. dofling roll 14 is relatively smooth-faced, as cornpared to the dofling cylinder 10 which is covered with fillet or metallic card clothing. The doffing roll 14 is given a very slightly roughened or textured surface, preferably by means of flutes, fine knurling, engraving, etching, or sandblasting. In many instances, a textured surface having very small cavities, such as prevails in the case of nat ural or synthetic rubber, leather or like-leather surfaces is suitable. In other instances flutes running along the axis of the rolls are preferred, for example from about 10 to 16 flutes per circumferential inch with the flutes having a depth of from about 0.02 to 0.05 inch have been found suitable. on a slight spiral to the longitudinaLaxis of the roll to provide for smooth riding of thenip blade 20 and prevent chattering of the blade. The fluted rolls have been found very desirable when dofling cotton fibers as the seed and trash material normally found with cotton will ride in the flutes and still allow-good contact between the roll surface and the nip blade. Dofling rolls which have smooth or slick surfaces are not generally suited for the application of the basic principles of the present invention.

A relatively flat flexible nip blade 20 is adjustably positioned on a pivot 24 and is capable of being placed in pressing tangential contact with the dofiing roll 14. Any suitable pressure-applying means, such as a helical spring 26, may be employed to cause the nip blade 20 to exert the desired pressure on the doffing roll 14. If desired, the flexible nip blade 20 may merely be placed in pressing contact with the dofiing roll 14 and lockedin that position. As shown in FIGURE 1, both-sides of the nip blade 20 extend tangentially'away from the surface of the dofiing roll 14, with the relatively short free end 28: ex-

tending forwardly up into the V-shaped throat formed by' the dofiing cylinder 10 and dofiing roll 14. The point of tangency of the nip blade 20 and the doffing roll114 is so located that the free end 28 of the nip .blade 20 is of relatively short length, and is only about A; of an inch up to about of an inch in length. As a result'of this extension of the free end 28, a relatively short entrance opening is formed between the short free end 28 and the surface of the doffing roll 14. The purpose of this small opening will be discussed hereinafter. T

The other end or the base portion 22 of the nip blade 20 also extends tangentially away from the surface of the doffing roll 14 and provides an exit opening of rapidly increasing size. The purpose of this exit opening of rapidly increasing size will also be discussed hereinafter.

Consideration of FIGURE 1 will reveal that the fibrous web W is carried forwardly on the surface of the dofiing cylinder 10 and is directed around the extending free end 28 of the nip blade 20 into the small opening or entrance formed by the free end 28 and the doffing roll 14. The fibrous web W is then pressed by the nip blade 20 against the doffing roll 14 for a very short length lo.

cated substantially at the point of tangency. Then, due to the exit opening of rapidly increasing size, the pressure It'is desired that the flutes be positioned V on the fibrous Web W is quickly released whereby it does not build up to accumulate or drag on the dotting roll 14 but is rapidly carried forwardly by any advancing means, such as a pair of rotatably driven nip rolls 30 and 32 mounted on

shafts

34 and 36 rotatably mounted in bearings in the card frame. The fibrous web W is then advanced for further process or handling, as desired or required.

FIGURE 2 is an enlarged view of the area of the dotfing roll 14 immediately adjacent to its point of tangency with nip blade 20. This figure illustrates the action on the fibrous web W by the nip blade 20 and the dofiing roll 14. The relatively short area of pressing contact is to be noted particularly whereby the possibility of frictional drag on the fibrous web is drastically reduced, thus decreasing the possibility of jamming and fiber accumulation on-the dofling roll 14. If the area of pressing contact becomes too large or too long, fiber accumulation and machine stoppages will occur.

Also illustrated in FIGURE 2 is (1) the common tangent line which passes tangentially between the .doffing cylinder and the dofiing roll 14 and (2) the common center line passing through the centers of the doffin-g cylinder 10 and the dotfing roll 14. These lines are, of course, at right angles to each other. The nip blade 20 is so inclined that its angular relationship with respect to the common tangent line is in the range of from 10 to about 35, with the preferred range extending from about to about 30. This angle is represented by the angle a in FIGURE 2, and, due to the geometric relationship involved, is also the angle between the common center line and a radius of the dofiing roll 14 which goes to the point of tangency of the dofling roll 14 and the nip blade 20.

In FIGURE 3 there is illustrated another embodiment of the present invention wherein corresponding parts are given reference numerals 30 higher than their counterparts in FIGURE 1. The basic difference in the two embodiments is the use of a curved or arcuate nip blade 50 in this embodiment, as compared to the relatively planar or flat nip blade used in the embodiment of FIGURE 1. The use of such a curved nip blade 50 which is convexly shaped with respect to the rotating surface of the dofiing roll 44 permits a wider entrance opening with a shorter free end 58 as well as an exit opening with an' even more rapid increase in size for the same length of the base portion 52 of the nip blade 50. Naturally, the length of the area of tangency is also decreased which is highly desirable.

In the embodiment of the invention illustrated in FIG- URES l and 3, relatively smooth-faced dolfing rolls 14 and 44 have been illustrated but it is not essential that the doffing rolls be relatively smooth-faced. As shown in FIGURE 4 wherein corresponding parts are given reference numerals 60 higher than their counterparts in FIGURE 1, a dofiing cylinder 7 0 cooperates with a rotatable dofling roll 74 which is mounted on a shaft 78 secured in bearings in the card frame 72. As illustrated in FIGURE 4, the dofiing roll 74 is provided with a peripheral surface having wire teeth 75 extending thereon. Such wire teeth may be either conventional fillets or metallic card clothing, as desired. Plush or pile fabric surfaces may also be used.

The dofiing roll 74 is illustrated adjacent to and spaced from'the dofiing roll 70 in very much the same relationship which exists between dofiing roll 14 and doffing cylinder 10. FIGURE 4 also illustrates another variation of the embodiment disclosed in FIGURES 1 and 3 in that the direction of rotation of the dofling roll 74 is opposite to the direction of rotation of the dofling roll 70. Additionally, it is also to be noted that the flexible nip blade 80, which is mounted on pivot 84 and is provided with a helical spring 86, a free end 88 and a base portion 82, is located on the opposite side of the point of closest adjacency of the dotling roll 74 and the dofling cylinder 70. As such, there is also provided an oppositely di- 6 rected V-shaped throat having arcuate sides leading to a narrow opening or clearance, as previously described.

The operation of the apparatus illustrated in FIGURE 4 is generally similar in principle to the forms of apparatus illustrated in FIGURES 1 and 3. Specifically, the fibrous web W" is carried forwardly on the surface of the dofiing cylinder 70, passes through the narrow opening or clearance, and is then directed under the short free end 88 of the nip blade 80. The fibrous web W is then pressed against the dofling roll 74 by the flexible nip blade substantially only at the point of tangency and is then carried forwardly on the surface of the dofi'ing roll 74 to be drawn forwardly by a pair of rotatable nip rolls and 92 mounted on

shaft

94 and 96 secured in hearings in the card frame 72. The web W" is then forwarded for further processing or handling, as desired or required.

It is not essential that the two rotatable surfaces used in the application of the principles of the present invention be a doffing cylinder and a dofiing roll. In FIGURE 5, there is illustrated a further embodiment of the present invention wherein a conventional main cylinder 98 and a conventional dofling cylinder 100 are employed, along with a doffing roll 104 and its associated nip blade 112.

The operation of the apparatus illustrated in FIGURE 5 is basically similar in principle to that of the other forms of apparatus illustrated in FIGURES l, 3 and 4. Specifically, a fibrous web W is carried forwardly on the peripheral surface of the main cylinder 98 and is carded by the card flats (not shown). The fibrous web passes downwardly between the nip or throat formed by the surfaces of the main cylinder 98 and the dofling cylinder 100 and is then directed under the short free end of a flexible nip blade 102 positioned in light-pressing, tangential contact with the peripheral surface of the dofling cylinder 100 in very much the same fashion as the nip blade 22 in FIGURES 1 and 2 is positioned with respect to dofiing roll 14 and doffing cylinder 10 therein.

The fibrous web is then lightly pressed against the dot]?- ing cylinder 100 by the flexible nip blade 142 substantially only at the point of tangency and is then carried forwardly on the peripheral surface of the doffing cylinder 100 and removed therefrom subsequently by dofling roll 104 and associated nip blade 112, or by any other desired doffing means, such as a dofiing comb, for example. The fibrous web may then be forwarded for further processing or handling, as desired or required;

An adjustable nip blade assembly 144 is employed to properly position the nip blade 142 and comprises a rotatable andadjustable base 146 provided with an adjustable screw mounting 148, The nip blade 142 is secured to the base 146 by any desired securing means.

In FIGURE 6 there is illustrated another embodiment of the present invention. A conventional dofling cylinder covered with conventional clothing either fillet or metallic is provided and rotates in the direction of the arrow shown. Mounted on a frame 161 immediately adjacent the dofi'ing cylinder is the dofiing roll 162. The dofiing roll is mounted for rotation on the shaft 163 mounted in the frame and rotates in the direction of the arrow shown. The doffing roll has flutes 164 on its outer surface. There are approximately 16 flutes per circumferential inch of the roll and the flutes have a depth of about 0.035 inch. The flutes run in the longitudinal direction of the roll on a slight spiral of about 1%,- inches.

A flexible nip blade 165 is adjustably positioned on pivot 166 mounted from the frame 161 and is capable of being placed in pressing tangential contact with the doffing roll. The nip blade is bent slightly at A to insure a line contact on the doffing roll and removes the blade from interfering with the fibrous web as it leaves the dofiing roll. Both sides of the nip blade 165 extend tangentially away from the surface of the doffingroll 162 with the free end 167 extending forwardly up into the V-shaped throat formed by the doffing cylinder and doff ing roll. The other end or base portion .168 extends tangentially away to the bend A. The base portion with the bend provides an exit opening of rapidly increasing .size.

The fibrous web F is carried forwardly on the-surface of the dofiing cylinder and is directed around the extending free end of the nip blade. The web is pressed by the nip blade against the dofiiing roll for a very short length cleaner roll rotates in the directionof the arrow shown- The cleaner roll is preferably felt-covered and is used to remove any fibers which may become wrapped about the -dofling roll.

Mounted behind the cleaner roll in light contact with the dofiing roll is the brushf 174. The brush is mounted on a stationary shaft 175 mounted in the frame.

The brush is used to keep the dofiing roll clean, that is, free of loose fibers.

The invention will be further illustrated in greater detail by the :following specific examples. It should be understood, however, that although these examples may .describe in particular detail some of the more specific features of the invention, they are given primarily for purposes of illustration and the invention in its broader aspects is not to be construed as limited thereto.

Example I The starting fibrous material, as positioned on the dofiing cylinder of a textile card, is a 45" wide card web of viscose rayon staple'fibers, Weighing about 75 grains per square yard and containing fibers having a substantially uniform average length of about F7 and a denier of about 1 /2. The peripheral surface linear velocity of .the dofiing cylinder is about 20 yards per minute. 'The dofiing cylinder is covered with metallic card clothing in FIGURE 1, and then passes between the nip blade and the dotting roll which also has a peripheral surface linear speed of about 20 yards per minute. A helical spring positioned on the nip blade pivot exerts a slight pres- .sure against the. nip blade whereby the fibrous web is .pressed against the surface of the dofiing roll only at the point of tangency.

The dolfing roll is steel and is relatively smooth-faced, as compared to the dotting cylinder which, as noted above, is covered with metallic card clothing. The doff- -ing roll has a slightly roughened or textured surface created by sand-blasting. The finish is referred to as a satin finish.

Immediately after such pressing action by the nip blade which takes place substantially only at the point of tangency, the fibrous web exits into a rapidly diverging opening and is relatively free to be drawn forwardly by a pair of rotatable nip rolls.

Examination of the fibrous web after it has passed .through the rotatable niprolls indicates that the predominant fibrous orientation has not been materially changed.

Examples 11 and III The procedures set forth in Example I are carried out substantially as set forth therein with'the exception that the speeds of the dofling cylinder and the doffing roll are both increased to (a) 30 yards per minutes and (b) 40 yards per minute.

The fiber transfer takes place with continued high efliciency and without disturbing the predominant fibrous orientation of the web to any substantial degree.

p 0 Example IV Examples V, VI and VII The procedures set forth in Example I are carried out substantially as set forth therein With the exception that the surface of the dofiing roll is slightly roughened or textured by means of (a) fine knurling, (b) fine engraved lines, and (c) relatively fine etching. The results are comparable to those set forth in Example 1.

Although the present invention has been described with particular reference to a doffing cylinder and a doffing roll which rotate with susbtantially the same peripheral surface linear speed, it is to be appreciated that the peripheral surface linear speed of the doffing roll need not neces' sarily be the same as that of the dofiing cylinder. For example, if the peripheral surface linear speed of the dofling roll is increased, so that it is greater than that of the dofiing cylinder, drafting of the fibers results whereby their par-allelization and alignment is improved in the long direction. In order to obtain such drafting of-the fibers, the ratio of the peripheral surface linear speed of the dofi'ing'roll to the peripheral surface linear speed of the dofiing cylinder should be greater than 1:1 and may be up to about 10:1, with preferred ranges being from about 1% :1 up to about 2 /2:1.

Example VIII Example IX The procedures of Example I are carried out substan tially as set forth therein except that a nip blade assembly as illustrated in FIGURE 5 is used to transfer the fibrous web from'the main cylinder to the doffing cylinder prior to its removal therefrom by the doffing roll. The problems of a vanishing Web are eliminated and'the operation is successful.

Example X The procedures of Example I are carried out substantially as set forth therein except that the peripheral sur-,

face linear velocity of the dofling roll is decreased to. (a) 15; (b) 10; and (c) 7 yards per minute. The device is operative and the results are comparable except that a heavier, more compacted and less oriented web is ob-- tained.

In the drawings, no driving means such as motors, pulleys, belts, gears, sprockets, and the like have been illustrated for the doffing cylinder, the doffing roll, or the pair of nip rolls. It must be understood that this has been I done because such driving means are conventional and well known in the art. Additionally, their omission from the drawings makes the individual figures thereof less complicated and easier to read and to understand.

Although several specific examples of the inventive concept have been described, the same should not be.

construed. as limited thereby nor to the specific features mentioned therein but to include various other equivalent features as set forth in the claims appended hereto. It is understood that any suitable changes, modifications and variations may be made Without departing from the spirit and scopcof the invention.

What is claimed is:

1. Apparatus for removing a fibrous web from a rotatable surface carrying the same which comprises:

a rotatable surface capable of carrying a fibrous web;

a rotatable roll capable of carrying a fibrous web and located immediately adjacent said first-mentioned rotatable surface whereby a V-shaped throat is formed between the rotatable surface and the rtatable roll; and

a stationary flexible nip blade in tangential contact with said rotatable roll and immediately extending away from said rotatable roll on both sides of the point of tangency therewith, one free end of said nip blade extending into the throat formed by the rotatable surface and the rotatable roll, whereby the fibrous web carried by the first rotatable surface is removed therefrom, carried around the free end of said nip blade into contact with the rotatable roll to be pressed thereagainst by the nip blade at the point of tangency and carried forwardly by the rotatable roll.

2. Apparatus defined in claim 1 wherein the stationary nip blade is arcuate and convex with respect to the rotatable roll.

3. Apparatus defined in claim 1 wherein the rotatable roll has an engraved finish.

4. Apparatus defined in claim 1 wherein the rotatable roll is fluted.

5. Apparatus for removing a fibrous web from a retatable surface carrying the same which comprises:

a rotatable surface capable of carrying a fibrous web;

a rotatable roll having flutes disposed longitudinally along the surface of the roll and on a slight spiral capable of carrying a fibrous web and said rotatable roll located immediately adjacent said first-mentioned rotatable surface whereby a V-shaped throat is formed between the rotatable surface and the rotatable roll; and

a stationary flexible nip blade in tangential contact with said rotatable roll and immediately extending away from said rotatable roll on both sides of the point of tangency therewith, one free end of said nip blade extending into the throat formed by the rotatable surface and the rotatable roll, whereby the fibrous web carried by the rotatable surface is removed therefrom, carried around the free end of said nip blade into contact with the rotatable roll to be pressed thereagainst by the nip blade at the point of tangency and carried forwardly by the rotatable roll.

6. Apparatus for removing a fibrous web from a rotatable surface carrying the same which comprises:

a rotatable surface capable of carrying a fibrous web;

a rotatable roll having from about 10 to 16 flutes per circumferential inch disposed longitudinally along the surface of the roll and at a slight spiral to the longitudinal axis of said roll capable of carrying a fibrous web and said rotatable roll located immediately adjacent said first-mentioned rotatable surface whereby a V-shaped throat is formed between the rotatable surface and the rotatable roll; and

References Cited by the Examiner UNITED STATES PATENTS 6/1932 Laurency 19-106 FOREIGN PATENTS Ad. 44,595 12/1934 France.

3,444 of 1862 Great Britain.

MERVIN STEIN, Primary Examiner.

DONALD W. PARKER, Examiner.

D. NEWTON, Assistant Examiner.

Claims

1. APPARATUS FOR REMOVING A FIBROUS WEB FROM A ROTATABLE SURFACE CARRYING THE SAME WHICH COMPRISES: A ROTATABLE SURFACE CAPABLE OF CARRYING A FIBROUS WEB; A ROTATABLE ROLL CAPABLE OF CARRYING A FIBROUS WEB AND LOCATED IMMEDIATELY ADJACENT SAID FIRST-MENTIONED ROTATABLE SURFACE WHEREBY A V-SHAPED THROAT IS FORMED BETWEEN THE ROTATABLE SURFACE AND THE ROTATABLE ROLL; AND A STATIONARY FLEXIBLE NIP BLADE IN TANGENTIAL CONTACT WITH SAID ROTATABLE ROLL AND IMMEDIATELY EXTENDING AWAY FROM SAID ROTATABLE ROLL ON BOTH SIDES OF THE POINT OF TANGENCY THEREWITH, ONE FREE END OF SAID NIP BLADE EXTENDING INTO THE THROAT FORMED BY THE ROTATABLE SURFACE AND THE ROTATABLE ROLL, WHEREBY THE FIBROUS WEB CARRIED BY THE FIRST ROTATABLE SURFACE IS REMOVED THEREFROM, CARRIED AROUND THE FREE END OF SAID NIP BLADE INTO CONTACT WITH THE ROTATABLE ROLL TO BE PRESSED THEREAGAINST BY THE NIP BLADE AT THE POINT OF TANGENCY AND CARRIED FORWARDLY BY THE ROTATABLE ROLL.