US3260078A

US3260078A - Padders or foulards

Info

Publication number: US3260078A
Application number: US260754A
Authority: US
Inventors: Leslie L Balassa
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-02-25
Filing date: 1963-02-25
Publication date: 1966-07-12
Anticipated expiration: 1983-07-12

Description

July 12, 1966 L. L. BALASSA 3,260,078

PADDERS OR FOULARDS Filed Feb. 25, 1963 INVEN LESLIE L. B SSA ATTORNE Y5 United States Patent 3,260,078 PADDERS OR FOULARDS Leslie L. Balassa, Creighton Lane, Scarborough, N.Y. Filed Feb. 25, 1963, Ser. No. 260,754 9 Claims. (Cl. 68202) The present invention relates to improvements in devices formed by at least one pair of rollers and used for the wet processing of fabrics and other web materials and particularly relates to padders or wringers used in the continuous preparation of wet processing of fabrics and other web materials.

In these operations the entire lot of fabric to be processed is run through the liquid bath, such as a dye bath, and through squeeze rollers for removing the excess liquid such as dye liquor, and providing uniform finishing results. Heretofore, it has been believed essential that to secure uniform dyeing and finishing results, the rolls must engage along their entire length to apply even pressure to the entire width of the fabric.

With devices of this type, it has been customary in the art to provide control positions at the two ends of the rolls for adjusting the compressive pressure of the rolls. During operation, this arrangement did not provide satisfactory results since the pressure applied by the rolls was not uniform over their entire length of the rolls due to the deflection or bending of the squeeze rolls under operatving pressures to form a generally concave surface. Due

to the deflection of the rolls, the pressure exerted by the squeeze rolls on the material passing between them was considerably greater at the end portions of the rolls than at the center portion. In an effort to compensate for the roll deflection, rolls have been built with crowns so that the rolls had a larger diameter at their center and tapered inwardly to the intended diameter at both ends of the rolls. This roll construction compensated for the deflection of the rolls at certain pressure ranges, but it did not eliminate roll deflection, which applied uneven pressure to the material passing between the rolls, such as when padders were used in the processing of fabrics of considerable thickness.

Another prior art construction attempted to obtain even pressure along the entire length of the squeeze rolls by applying the roll compressing force through auxiliary rolls over the entire length of the rolls. This construction allowed the use of uniform diameter rolls since the compressive force was distributed along the entire length of the rolls. Padders equipped with such secondary devices gave uniform dyeing results when used with light weight to medium weight woven fabrics. However, in the dyeing or processing of heavy, thick, spongy or folded fabrics even the rolls which had a force applied along their entire length, applied an uneven pressure to the 'edges of these fabrics, resulting in an uneven dyeing with the fabric usually being considerably lighter in shade at the edges than in the center of the fabric. Attempts to overcome this defect of the padders by coating the squeeze rolls with thick layers of soft rubber were generally unsuccessful, particularly in the case of the thick, spongy or folded fabric, or tubular knit fabric. Under the combined effects of the temperature of the pad liquor, the chemicals used in the liquor and the roll pressure, the soft rubber of the roll covers gradually hardens. The hardening of the rubber is usually uneven with the most pronounced degree of hardening occurring at the points of greatest pressure, i.e., at the points where the edges and folds of most of the fabrics run. The gradual hardening of the rubber has added to the edge dyeing difficulties present even in the fresh soft rubber roll coverings.

3,260,073 Patented July 12, 1966 The squeeze rolls of all padders are several inches longer than the width of the fabrics which they are designed to process. Generally they are longer by three to five inches or more at either end of the rolls. This excess length at each end of the rolls, which is considered essential for the proper operation of the padder, is unsupported by the fabric when the rolls are pressed together during operation. The edges of the fabric have to absorb the excess pressure.

In the padders equipped with soft rubber-covered rolls, the excess pressure applied to the edges of the fabrics is only partly relieved by the fabric edges being pressed deeper into the soft rubber covering and allowing the two pressure rolls to come into direct contact along their length not squeezing the material being processed. The compressed soft rubber exerts greater pressure on the fabric where the fabric edges are driven into it.

It is well known in the art that fabrics and webs which are folded during wet processing, cannot be processed satisfactorily and uniformly in conventional padder type equipment even when the rolls are covered with soft rubber. During a dyeing operation, the material along the folds of the fabric being processed has invariably a lighter shade when it is being dyed in the padder or has a lower moisture content when the padders are used as squeeze rolls or has a lower percentage of finishing materials when the padders are used in finishing operations. There is a difference in the behavior of the fabric as it is passed between the padder rolls in the flat condition as compared to its folded condition. The material of the outer surface along both sides of each fold line is under tension, while the material of the inner surface adjacent both sides of each fold line is under compression. It takes a substantially lower pressure applied to the folds than to the flat portion of the fabric to equal the results obtained in the flat portion remote from the fold lines of the fabric. Consequently, when using conventional padder rolls, no matter how soft the covering of the rolls was made, and without regard to the painstaking care exercised in maintaining a uniform pressure over the entire width of the material being processed, including the folded edges, the processed materials showed marked differences in result from the roll operation at the edges from that of the rest of the fabric or web.

In accordance with the present invention, the previous deficiencies and defects have been overcome and uniform results are obtained in wet processing fabrics and webs of considerable thickness by eliminating the cantilever effect between the edge of the fabric or web and the unsupported portions of the squeeze or pressure rolls. This is accomplished by providing suitable support for the squeeze rolls between the edges of the fabric and the corresponding end of the rolls.

If the presssure applied to the folded edges is carefully adjusted and controlled to be of a determined amount less than the pressure applied to the rest of the material, a uniform treatment of the material, including its folds, is obtained. A possible explanation of these results is that the pressure applied externally by the rolls to the folds plus the factor of compression of the material Within the folds is equal or nearly equal to the pressure applied to the flat parts of the material. This would indicate that to obtain uniform results, the fold must receive a substantially lower pressure from the padder rolls than the rest of the material. The correctness of this analysis was tested in a series of experiments, some of which are shown in the examples below.

Due to the complex nature of the above-mentioned compression factor, it is diflicult to assign to it a reliable mathematical formula. The compression factor is affected and in many respects controlled by many variables such as the thickness of the web or fabric; the structure of the fabric, including the twist of the threads; the type of weave and/or knitting; the nature of the material (i.e. cotton, rayon, nylon, etc); the nature, composition and temperature of the finishing material or solution-applied; the speed with which the material, i.e. the web passes through and between the padder rolls; and the relative hardness of the padder rolls.

In view of the complexity of the compression factor and the unavailability of a mathematical formula for it, the proper ratio of pressure to be applied by the compression rolls at the folded edges of the material as compared to the rest of the web, had to be determined empirically from fabric to fabric. Preferably the ratio of the pressure applied to the flat part of the web to that of the folded edges had to be between the range of 100140 and 100:85 to give uniform processing results as demonstrated in the examples below.

In accordance with the present invention, adjustable localized pressure is applied to the rolls opposite to the compressive pressure to reduce the pressure applied by the rolls to the edges of a folded piece of fabric being passed through the rolls.

Another object of the present invention is to apply a different pressure to the edges of the folded fabric passing through the rollers than to the remainder of the fabric width.

A still further object is to provide a differential in pressure applied to the edges of a variety of widths of fabric in a simple, facile manner without impairing the operability or eihciency of the roller operation.

Further objects of this invention will be apparent from the following description and the following drawings wherein:

FIGURE 1 is a diagramatic end view of a padder in operation in accordance with the present invention;

FIGURE 2 is a partial front view in section of a portion of the pressure rolls in accordance with the present invention at the edge of the folded fabric being processed;

FIGURE 3 is a partial front view in section of pressure rollers showing the present invention;

FIGURE 4 is a partial front view in section of the pressure rollers showing a further embodiment of the present invention; and

FIGURE 5 is a partial front view in section of the rolls showing a further embodiment.

Referring to the drawings, FIGURE 1 shows one type of padder having a generally shallow, single dip padder box, with two

rotary rollers

12 and 14 which are adapted to rotate about

shafts

16 and 18, respectively.

Shafts

16 and 18 revolve in

corresponding bearings

20 and 22, respectively. Bearings 22 are stationary and mounted in frame 21. Bearings 20 are pivotally mounted to frame 21 about pivot mounting 24 in arm 26. While the desired compressive force could be applied to

rollers

12 and 14 in any of the conventional ways, the compressive force is applied at the ends of shaft 16 by suitable means, illustratively shown in FIGURE 1, by a screw arrangement 28 pivotally attached to the end of arm 26 opposite to pivot mounting 24.

In the case [of a padder for dyeing of fabrics, the fabric indicated by numerals 30 is caused to enter the dye liquor 32 contained in padder box 34. Fabric 30 passes about

rollers

36 and 38 to insure complete submersion in dye liquor 32 and thence between

rollers

14 and 12. The fabric could be passed through succeeding dye baths if desired, or if no further bath or treatment is necessary, the fabric could be wound on a take-up roll, or to a drying unit, all of which are not shown.

FIGURE 2 shows one embodiment of how the desired pressure differential between the edge fold 40 and the flat portion 42 of the fabric 30 which is being treated may be obtained.

Rollers

12 and 14 have a resilient

outer covering

44 and 46, respectively, which is preferably soft rubber. interposed between each edge 40 of the folded web 30 and its corresponding end of

rolls

10 and 12 is a spacer 48, such as a ring annulus or a belt, which is of a predetermined thickness greater than edge fold 40, so that spacer 48 depresses the soft rubber coverings 44 and 4-6 to reduce the pressure at and adjacent to edge folds 40. As illustrated in FIGURE 2, spacer 43 is in the form of a ring. In this form it can be slidably mounted about and properly positioned on the desired roll, shown as roll 14, in an easy manner. Preferably spacer 48 can have a width from one-half inch to over two inches. Good results are obtained with a two inch wide ring. Before

rolls

12 and 14 are compressed, spacers 48 are positioned about roll 14 to be contiguous to each of the edge folds 40 of fabric 30. The desired compressive force is applied to

rolls

12 and 14 through means 28. Spacer 48 is of sufficient thickness and rigidity to depress

rubber coverings

44 and 46 of

rolls

12 and 14, sufliciently to-reduce the pressure applied to the fabric edge 40. During operation,

rubber coverings

44 and 46 are depressed to reduce the compressive force applied to fold edges 40 to provide uniform processing results over the entire width of fabric 30. Spacer 48 exerts a localized counter force to the compressive force applied by rollls 12 and .14.

Spacer 48 could be in a form of an endless belt having the desired thickness width and rigidity, and passing between

rolls

12 and 14 juxtapositioned to edge fold 40 of fabric 30. The belt can be positioned and supported in any convenient manner, such as by a bar, roll, wheels or idler pulleys, and the rotation of

rolls

12 and 14 would drive the belt.

Advantageously, spacers 48 are positioned as close to the edges 40 of the fabric 30 being processed as is practioable within the limits of the guiding mechanism controlling the passage of the material through the padder. Spacers 48 should be run within 4;" (one-eighth of an inch) of the edge of the fabric, and if the distance between spacer 48 and the edge 40 of the fabric 30 is increased, the thickness of spacers 48 is increased at least by 50 percent for each additional /8" increment.

While spacer 48 is shown in FIGURE 2 as rectangular, it could have other cross-sectional geometric configurations, such as triangular, elliptical or circular. When a padder having horizontal rolls is used, good results are obtained when spacer 48 is wedge-shaped, such as a generally triangulair cross-section. The wedge-shaped sp-acer has a gradual taper and is mounted to have its thickest portion closest to the edge of the fabric being processed.

Another embodiment of the present invention is shown in FIGURE 4, which embodiment is effective in reducing the pressure at edges 52 of a relatively thick fabric 54, such as knitted fabrics.

Rolls

56 and 58 have a

soft rubber coating

60 and 62, respectively, thereabout. Roll 53 has one or more hollow channels 64 of about one inch width each and of sufficient depth to be about equal to the thickness of fold 52 of web or fabric 54 being processed. Channels 64 are customarily in the steel shell of the rolls.

Rubber coatings

60 and 62 are relatively thin.

Channels 64 are circumferentially placed on the rolls at locations where the edge fold of the fabric being processed will be aligned therewith. When compressive pres sure is applied to

rolls

56 and 58, the excess pressure on the edge folds 52 forces rubber coating 62 into channel 64, thereby relieving the excess pressure applied to edge folds 52.

Where paddens are used for processing a variety of widths of material, a channel has to be provided for the edges of each width of material. The flat portion of fabric 54 is not forced into channels 64 which it overlies because of the relatively small width of the channel and no excess pressure is applied by the rolls.

Advantageously, each roll could have channels ialigned for relieving the pressure exerted in the edge fold-s to reduce the depth of the individual channel.

A further embodiment is shown in FIGURE 3. Here one of the rolls, 70, has a plurality of circumferentially disposed annular rings 72 fixedly mounted circumferentially about roll 70 forming part of its rubber coating. Annular rings 72 are positioned to correspond with the edges of the fabric to be processed. Rings 72 are preferably formed from fiber cord or wire reinforced rubber of substantially the same hardness as the rubber covering on the rest of the roll. Each of rings 72 has a space or reservoir 74 therein. Steel roll 70 carries a port or conduit 76 communicating with each space 74 in a corresponding ring 72. Conduit 76 is provided with a hydrau- =lic or pneumatic pressure system, such as a pump, by which the pressure within space 74 of ring 72 can be regulated to suit the fabric 78 being processed and the treatment desired. Through the close control of the pressure applied within rings 72, the pressure ratio. applied by

rolls

70 and 84 to the fabric 78 may be varied from below atmospheric pressure to above the pressure (applied by the padder. In operation rings 72, which are aligned with the edges 80- of fabric 78 being processed, are expanded by pressurized fluid introduced into spaces 74 of rings 72 via conduit 76. When expanded, ring 72 depresses coating 82 on roll 84 adjacent its correspondi-ng edge 80 of fabric 78 as indicated at 85, thereby reducing the pressure applied to edge 80 by

rolls

70 and 84. The greater the pressure, the greater the protuberance of ring 72, so that the depress-ion of coating 82 can be closely controlled.

By the use of parallel pairs of rings 72 disposed longitudinally along roll 70 and aligned with the edge folds of various standard widths of fabrics and with provisions for individual pressure control for each ring, a single set of padder rolls may serve for the processing of a wide variety of fabrics of differing Widths.

When padders are used in processing a variety of fabrics with differing widths, a set of pressurized rings 72 has to be provided for the edges of each width of fabric. Advantageously, during operation of such a multi-ring padder, rings 72 underlying the flat portions of fabric 78 are pressurized to equal the pressure of the padder rolls. The operating rings, i.e. those which correspond with the edges 80 of the fabric 78 being processed, have a greater pressure applied via conduits 76 than the pressure applied by

rolls

70 and 84, and ring 72 expands and depresses coating 82 at 85, which reduces the pressure applied to edges 80, so that edges 80 pick up the same or nearly the same quantity of pad liquor as the more centrally located parts of fabric 70. The optimum ring pressure, which results in a uniform treatment of the fabric being processed, has to be determined empirically for the different fabrics, treatments, materials and conditions during operation and is within the skill of the art.

It may be desirable when particularly sensitive fabrics are'being treated and have a particularly thick end fold to combine the use of a spacer 48, such as a ring or a belt, to depress the covering over a channel 64 or instead of applying pressure within space 74, apply a suction source to depress the covering of ring 72 and provide the minimum resistance and pressure at the folds of the fabric although the rest of the fabric may be exposed to substantial pressure.

Another embodiment is shown in FIGURE 5. Roll 94 has one or more hollow channels 96 of about one 7 inch width and a depth equal to or greater than the edge channel 96. Roll 94 has a conduit 104 which communicates with channel 96 and has a pressure system, such as shown in FIGURE 3, by which the pressure within channel 96 can be regulated to suit the fabric being processed. The pressure within channel 96 can be reduced below the roll pressure by a selected amount to provide even color distribution.

Using a series of parallel spaced ribs 102, a roll can be .used to process a variety of widths of fabrics. The ribs 102 adjacent the edges of the fabric are radially contracted by a reduction in pressure by a selected amount within its corresponding channel 96 to obtain the desired results. The other channels 96 underlying the flat portions of the fabric being processed have a pressure ap plied which equals the pressure of the rolls.

The padder rolls may be placed in any desired angular position to each other. They may be disposed vertically, horizontally or any other angular relationship to each other. The basic vertical padder is shown in FIG- URE 1.

It should be noted that wherever steel shell is mentioned, it is understood to refer to any metal suitable for the purpose with suflicient structural strength to resist deflection or deformation under pressure. Wherever a rubber covering is mentioned, it is understood to refer to any suitable elastomeric material of either natural or synthetic origin and having suflicient resistance to deformation under operating pressures and temperatures and having a satisfactory chemical resistance with respect to the process and material being used.

Detailed test data on the apparatus of the present invention are presented below.

In the examples below, the following equipment was used and in the tables, the reference numerals refer to the numeral adjacent equipment below and indicate that this piece of equipment was used.

Padder I-Vertioal type.Two rubber-covered rolls slanted at an angle, with the upper roll about 45 in front of the bottomroll.

Specifications Length of rolls 60". Diameter of rolls 14". Covering of rolls Soft rubber, 60 Shore Durometer 1" thick.

Liquor box:

(a) shallow, single dip.

(b) shallow, double dip.

Maximum pressure 10 tons. Cloth speed Variable25-1S0 yards per minute. Paddcr HHoriz0ntal type-Two rolls in horizontal arrangement.

Specifications The same as in Padder I above, with the exception of- Liquor box:

(a) shallow through between rolls (b) deep through over rolls Auxiliary Equipment:

The following auxiliary equipment was used in conjunction With the padders in the examples:

same as (3) except The shade differentials were determined by visual observation, in north light. In each case the center of the fabric was accepted as the basis for comparison to which the edge was compared. The center was considered to be within 3" on either side of the geometric center, while the edge was taken within one inch of the edge or selvage of the fabric. The tests were made on parts of each run at least 20 yards from point of start, i.e. when padder reached intended speed.

In Table A data are presented on the use of rings and belts of different hardness (auxiliary equipment 1, 2, 3, and 4 above) and thickness. As is demonstrated in Table A, the vuse of auxiliary equipment 1-4 of suificient thickness and propenly positioned in close proximity to the fabric edge prov-ides uniform and even dyeings.

Table A Material processed: Cotton suiting-Dobby weave 36, 2 yards/lb.

Pad liquor:

Procion Blue I-IB1.5% fiber reactive dye. Pad liquor prepared and pad steam process carried out in accordance with the dye manufacturers directions (Imperial Chemical Industries, Ltd., Method 1,

1961). Equipment: Padder 1(a). Roll pressure: 8 tons. Material speed: 100 yards/min. Pad liquor pickup: 60%.

1 Not used.

The auxiliary equipments were positioned about 4;" from the edge of the fabric. The rings, auxiliaries 1 and 2 were fitted on the bottom roll.

The tests show that using a spacer placed adjacent the side edges of the fabric gives better results than using no auxiliary equipment. Also, the tests show that a belt or ring of the same hardness and thickness gives about the same results.

The data presented in Table B demonstrates the effect of the position of the belt on the roll and its thickness in relation to the edge told of the material being processed.

Table B Material processed:

Cotton girapery fabric, Dobby Weave, bleached, 50 9/18 x 18, 19 oz. per yar Pad liquorand method:

Same as used in Examples of Table A; Equipment: Padder 1(a); Roll pressure: tons. Material speed: 100 yards per minute. Pad liquor pickup: 65 Auxiliary: N0. 3, Rubber belt, 4 wide.

Table C Material processed:

Same as used in Examples of Table B; Pad liquor and method:

Same as used in Examples of Table 13; Equipment: Padder 1(a); Roll pressure: Varied from 3 to tons; Material speed: 100 yards per minute; Pad liquor pickup: variable, depending on roll pressure; Auxiliary: N0. 3 Belt, 4 wide.

Auxiliary s Distance from Edge, inch Auxiliarys Thickness, mm.

Depth of Shade of Edge (Center considered Roll Pressure, Tons Examples 1 Not used.

The results of the examples of Table C demonstrate that increasing the compressive pressures applied to the rolls, thicker auxiliary equipment must be used to secured satisfactory results.

Data are presented in Table D on the effect that variations of speed of the material being processed has on the uniform results of the process along the width of the fabric.

Table D Material processed: Same as in Table B;

Pad liquor and method: Same as in Table B; Equipment: Padder I00);

Roll pressure: 5 tons;

Material speed: to 150 yards per minute;

Pad liquor pickup: to

Auxiliary: No. 3, Belt, 4 wide, distance from edge }4.

Material Thickness Depth of Shade Examples Speed, of Belt, of Edge (Cen- Yd./Min. mm. ter considered 1 Auxiliary not used.

The results of Examples 3851 of Table D show that the higher the speed, the thinner the added spacer need be to obtain uniform shading results.

Data is presented in Table E demonstrating the eitect of application of pressure by annular pressure rings on the uniform dyeing of circular-knit tubular fabrics.

9 Table E Material processed:

Cotton, circular jersey, 2 yards 2 per lb. bleached, processing width 36 from fold to fold; Pad liquor and method:

Same as in Examples of Table B; Equipment: Padder II(a); Roll pressure: 4 tons; Material speed: yards per minute; Channel pressure: Variable; Pad liquor pickup: to

Auxiliary: No. 5, Annular pressure rings, each about 1' wide positioned 18" either side of center on both rolls. The rings have an outer surface of the same quality and hardness as the rolls covering.

The results of the examples of Table E demonstrate that at a certain reduced pressure applied to annular channels to control the depression of the flexible ribs adjacent the fabric edge, gives uniform dyeing throughout the entire width of the fabric. Increasing the pressure gives unsatisfactory results.

The annular pressure channels tested in Examples 52-5 6 were also tested in resin finishing of rayon circular knit tubular fabrics. 30

Table F Weight Increase Channel Examples pressure,

p.s.i. Center, Edge Fold,

Percent Percent r 167 5.2 as 135 5.4 4.3 115 5.0 4.9 5. 0 5. 2

In Examples 57-60 the differential pickup between center and the end folds was determined by weighing fabric cuts from center and from edge folds, one inch either side of fold and including the fold.

The results of Examples 57-60 demonstrate that when a selected localized pressure is applied counter to the 55 roll pressure adjacent the edges of the fabric being processed by annular pressure rings, optimum and uniform results are obtained. With the equipment shown, pressure of about 100 p.s.i. would give best results.

The data of Table G demonstrates the relationship of 60 material speed and annular ring pressure to the edge fold dyeing of circular knit tubular fabrics.

The results show increasing the material speed required higher pressures to give uniform dyeing results over the width of the fabric.

The data of Table H demonstrates the effect of using a wedge-shaped auxiliary in combination with pressurized annular rings on horizontal padder rolls.

Table H Material processed: Same as in Examples of Table E;

Pad liquor and method: Same as in Examples of Table E;

Equipment: Same as in Examples of Table E;

Auxiliary: No. 3 Wedge-shaped belt, 4" wide, thickest part running within 54" of edge of told and within 34," of the pressurized annular ring measured from the outside, i.e. closest to the end of rolls. Belt 4 mm. thick at thickest part;

Roll pressure and material speed: Same as in Examples of Table E.

Channel Pressure, Depth of Shade of Examples p.s.i. Edge Fold (Center considered 100) As has been demonstrated above, applying a selected localized opposing force to the rolls of a padder apparatus adjacent the edges of the fabric being processed, provides uniform processing results to the fabric, which were unattainable with previous padders. Thus, the apparatus of the present invention results in the edges of a folded fabric being dyed substantially the same shade as the flat center portion.

While both rolls were shown covered by a resilient material, only one roll could be so covered.

It will be apparent to those skilled in the art that various changes may be made in the construction of the present invention without departing from the spirit and scope of this invention, which is defined by the appended claims.

What is claimed is:

1. In a padder for finishing operations to a strip of fabric comprising a pair of parallel contiguous rolls adapted to revolve in opposite directions, means for applying a compressive force to said rolls, one of said .rolls having a resilient covering thereabout, the other of said rolls having a pair of spaced apart circumferential channels therein about its outer periphery, each of said channels being aligned with a corresponding axial edge of said fabric, a resilient band covering a corresponding one of said channels and adapted to be expanded or contracted in response to the pressure within said channel, a resilient cover of substantially the same thickness as said bands mounted about the remaining 0 surface of said other roll, means forming fluid-tight seal between said band and said corresponding channel, a fluid pressure system carried by said other roll and communicating with said channels, means for controlling the pressure applied to said channels by said system to vary the relative radial position of the outer surface of said bands to the outer surface of the cover of said other roll during operation.

2. In a padder for finishing operations to a strip of fabric comprising a pair of parallel contiguous rolls adapted to revolve in opposite directions, means for applying a compressive force to said rolls, a pair of spaced apart circumferential depressions in one of said rolls aligned with a corresponding axial edge of said fabric, said depressions having a depth at least equal to the thickness of the corresponding axial edge of said fabric, said one roll having a resilient covering thereabout.

3. In a padder for finishing operations to a strip of fabric comprising a pair of parallel contiguous rolls adapted to revolve in opposite directions, means for applying a compressive force to said rolls, one of said rolls having a resilient covering thereabout, a plurality of flexible ribs circumferentially mounted about said other roll in predetermined spaced arrangement, said ribs having a hollow annular channel in said roll below said ribs, the outer peripheral surfaces of said ribs being movable relative to the peripheral surface of said one roll, :a plurality of pressure conduits carried by said other roll, each conduit communicating with a corresponding hollow annular channel, a fluid pressure source communicating with said conduits, and means for selecting the pressure of the fluid in each hollow annular channel for selectably positioning the peripheral surface of each rib with respect to the peripheral surface of said one roll.

4. In a padder for finishing operations to a fabric, comprising a pair of contiguous rolls adapted to revolve in opposite directions, wherein means .are provided for applying a compressive force to said rolls, at least one of the said rolls including a resilient cover adapted to normally compress the edges of the fabric passing between said rolls, the improvement comprising means for causing deformation of said resilient cover adjacent an axial edge of said fabric thereby substantially reducing only the pressure applied to said fabric edge to a value such that the pressure applied by said roll-s to said edge is substantially equal to the pressure applied by said rolls to the remainder of said fabric passing between said rolls.

5. In a padder for finishing operations to a fabric, comprising a pair of contiguous rolls adapted to revolve in opposite directions, wherein means are provided for applying a compressive force to said rolls, said rolls including a resilient cover adapted to normally compress the edges of the fabric passing between said rolls, the improvement comprising an annulus of material firmer than said resilient cover for causing deformation of said resilient cover adjacent an axial ege of said fabric, thereby sufiiciently reducing only the pressure applied to said fabric edge to a value such that the pressure applied by said rolls to said edge is substantially equal to the pressure applied by said rolls to the remainder of said fabric, said annulus being adapted to be mounted about said resilient cover adjacent an axial edge of said fabric and having an inner diameter substantially equal to the outer dimeter of said resilient cover and said annulus having a thickness adjacent said fabric edge greater than the thickness of said fabric edge.

6. In a padder for finishing operations to a fabric, comprising a pair of rolls adapted to revolve in opposite directions and contacting each other along a common generatrix, wherein means are provided for applying a compressive force to said rolls, said rolls including a resilient cover adapted to normally compress the edges of the fabric passing between said rolls, the improvement comprising a spacer passing between said rolls adjacent to a longitudinal edge of said fabric for causing deformation of said resilient cover adjacent said edge, thereby substantially reducing only the pressure applied to said fabric edge to a value such that the pressure applied by said rolls to said edge is substantially equal to pressure applied by said rolls to the remainder of said fabric, said spacer being more rigid than said resilient cover and having a thickness adjacent said fabric edge greater than the thickness of said fabric edge.

7. In a device according to claim 5, wherein the annulus comprises a ring slidably mounted about said resilient cover.

8. In a device according to claim 6, wherein the spacer comprises an endless belt passing between said rolls.

9. In a device according to claim 5, wherein the annulus is of a sufiicient thickness to deform said resilient cover so that the pressure applied by said rolls to said fabric edge is between about 40% and about of the pressure applied by said rolls to the flat portion of said fabric.

References Cited by the Examiner UNITED STATES PATENTS 206,489 7/1878 Sargent 6822 315,910 4/1885 Charlesworth 68202 X 1,182,426 5/ 1916 Sargent. 1,556,700 10/1925 Lee 68267 X 2,080,048 5/1937 Kauifman 68267 X 2,147,853 2/1939 Mokrohajsky 68267 2,262,009 11/1941 Kreeft 68202 3,010,148 11/1961 Dasher 155 X IRVING BUNEVICH, Primary Examiner.

Claims

4. IN A PADDER FOR FINISHING OPERATIONS TO A FABRIC, COMPRISING A PAIR OF CONTIGUOUS ROLLS ADAPTED TO REVOLVE IN OPPOSITE DIRECTIONS, WHEREIN MEANS ARE PROVIDED FOR APPLYING A COMPRESSIVE FORCE TO SAID ROLLS, AT LEAST ONE OF THE SAID ROLLS INCLUDING A RESILIENT COVER ADAPTED TO NORMALLY COMPRESS THE EDGES OF THE FABRIC PASSING BETWEEN SAID ROLLS, THE IMPROVEMENT COMPRISING MEANS FOR CAUSING DEFORMATION OF SAID RESILIENT COVER ADJACENT AN AXIAL EDGE OF SAID FABRIC THEREBY SUBSTANTIALLY REDUCING ONLY THE PRESSURE APPLIED TO SAID FABRIC EDGE TO A VALUE SUCH THAT THE PRESSURE APPLIED BY SAID ROLLS TO SAID EDGE IS SUBSTANTIALLY EQUAL TO THE PRESSURE APPLIED BY SAID ROLLS TO THE REMAINDER OF SAID FABRIC PASSING BETWEEN SAID ROLLS.