US2849781A - Method and machine for shrinking knitted fabrics - Google Patents

Description

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K. I. J. ROSEN Sept. 2, 1958 METHOD AND umcams ma snamxmc; KNITTED memes Filed Feb. 12, 1954 9 I IIIIIIIIIIIIIIIII III/III III Sept. 2 1958 1. J. ROSEN us'mon AND'IIACHINE oa sanmxmc xnrmib flames Filed Feb..12, 1954 2 Sheets-Sheet 2 United lVIETHOD AND MACHINE FOR SHRINKING KNITTED FABRICS Karl Isac Joel Rosn, Ulricehamn, Sweden, assignor to Sven Audersson, Ljungskile, Sweden The present invention relates to a method and a machine for shrinking knitted fabric. At the present time there is on the market one such method, the so-called Redman process, according to which the fabric, while moist, is stretched vigorously in the breadth, so that the meshes are shortened on the length. This method, however, suifers from several drawbacks. There is hardly any unshinkability, as a comparatively great shrinkage remains owing to the strong stretch. Besides, the apparatus used will be very expensive.

It is already known according to the U. S. Patent No. 2,262,268 to shrink woven fabric in the length by steaming it and thereafter allowing it to pass between smooth elastic webs running on rollers rotating at diiferent speed.

Such a process, however, is not suitable as far as the shrinkage of knitted fabric is concerned, as the threads, unlike those of the woven fabric, do not form warps and wefts which are substantially at right angles to one another.

According to the present invention the smooth elastic webs have been replaced by endless stainless helical springs provided in grooves in the rollers, which springs, as they are unwound from the end of one of the rollers, are led via pulleys to the opposite end of the other roller (see Fig. 1). Instead of steaming the knitted fabric before it is led between the elastic webs, all the rollers with the endless springs are enclosed in a steam and heating chamber, so that the knitted fabric is exposed to the action of steam and strong heat during the whole shrinking process. The steam is generated in two open shallow water containers which are filled automatically, the bottoms of said containers being provided with electric radiators. The containers are enclosed in the heating chamber close to the fabric delivery rollers. Owing to the structure of the steel springs a firm but gentle grip on the knitted fabric is attained throughout the present process, the knitted fabric being, during the whole shrinking process, Which is bi-directional, exposed to steam and heat, and according to the present process the meshes of the fabric can move more freely than when they are exposed to the action of smooth rubber webs.

The shrinkage of the breadth is brought about due to the fact that the longitudinally spaced rollers over which the knitted fabric passes in succession and the peripheries thereof are driven at progressively lower speeds in the direction of travel of the knitted fabric through the machine and also have their respective grooves located progressively closer together. That is to say, the flights of the endless springs converge from each side toward the center in the direction of motion of a web of knitted material through the machine between the upper and lower sets of springs, this bringing about a shrinkage in the material in the direction transverse to its direction of run through the machine.

The invention is illustrated by an embodiment in the drawing in which Fig. 1 is a vertical sectional view of the machine housing and with the rollers and springs of the machine shown in elevation, Fig. 2 is a diagrammatical tates Patent side view of the rollers and the endless springs, and Fig. 3 is a side view of the rollers with driving chain.

In the drawing the reference numerals 1-7 designate rollers of equal diameter mounted in a frame 8, the two upper rollers 1, 2 and the two lower rollers 6, 7 respectively are placed opposite each other, while the other rollers 3, 4, 5 are placed in staggered relation between the upper and the lower pairs of rollers. The rollers 1-7 are driven by an endless chain 9 by means of chain wheels 11-17 connected with the rollers 17. The chain wheels 11 and 12 for driving the two upper rollers 1, 2 have equal diameters as have also the chain wheels 16, 17 for driving the lower rollers 6, 7, but the diameters of the latter chain wheels are greater than those of the upper rollers, while the diameters of the chain wheels 13, 14 and 15 for driving the interjacent rollers 3, 4 and 5, respectively increase gradually from the top downwards, so that the velocity of the rollers decreases gradually from the top downwards. The rollers 1, 3, 5, 6 on one half of the machine are driven in the opposite direction of those on the other half.

The rollers are provided with peripheral wedge-shaped grooves 18, the grooves being closer as the diameters of the chain wheels of the rollers increase.

As indicated in Fig. 2, one set 19 of endless helical springs forming one web are placed in the grooves 18 of the rollers 1, 3, 4, 5 and 6 and these are driven in the direction indicated by the arrow. A second set 20 of endless helical springs forming a second web are placed in the grooves 18 of the rollers 2, 3, 4, 5 and 7 and these are driven in the direction indicated by the arrow with the result that the adjacent runs of the webs formed respectively by the two sets 19, 20 of springs move in the same direction between the feeding set of rollers 1, 2 and over the intermediate rollers 3, 4 and 5 and between the trailing or delivery set of rollers 6, 7. The web of material to be shrunk (not shown) enters at the rollers 1, 2 between the pair of spring webs formed by the two sets of springs 19, 20, travels between these webs and the intermediate rollers 3, 4 and 5, at progressively lower speeds as the springs contract, and leaves between the rollers 6, 7. Pulleys 21' are provided to guide the sets of springs as they pass from their lower rollers 45, 7 back to their upper rollers 1 and 2. The upper and lower rollers such as rollers 2 and 7 are each provided with means 22' for urging the same in the direction of their companion rollers 1 and 6. As shown in Fig. l, the rollers and springs and driving chains are enclosed within a casing 25 and the rollers are driven by a motor 26 located outside the casing. In the lower part of casing 25 is a trough 27 supplied with water from an external source 28, and an electrical heater unit 29 beneath furnishes the necessary heat to convert the water into steam.

Owing to the different velocity of the rollers the helical springs will be stretched during the motion towards the upper rollers, but when they disengage the rollers at the points 21, 22, 23, 24, they are contracted again and shrink the knitted fabric in the longitudinal direction.

Owing to the fact that the helical springs of each set converge toward the center of the set or web in the direction of travel of the web of material to be shrunk between the webs the knitted fabric will also be shrunk in the transverse direction, thereby to establish alternate grooves and ridges running in the direction of travel of the fabric between the webs. Thus the knitted fabric will take on a corrugated characteristic, which adds to its appearance.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

1. In an apparatus for shrinking a web of knitted fabric, a pair of sets of endless helical springs having adjacent runs disposed in web feeding relation and between which the fabric web is passed for shrinking, the endless springs of each set forming said adjacent runs converging toward the center in the direction of travel of the fabric web therebetween, and means for driving the web entering ends of said sets of endless springs faster than the ends at which the fabric web is discharged whereby said adjacent runs of the endless springs of each set contract to thereby condense the fabric web in the longitudinal direction and simultaneously condense the fabric web in the transverse direction.

2. An apparatus as defined in claim 1 for shrinking a web of knitted fabric wherein said endless springs of each set are mounted on rollers, each said roller being provided with a groove individual to each endless spring.

3. In an apparatus for shrinking a web of knitted fabric, a pair of sets of endless helical springs having adjacent runs disposed in web feeding relation and between which runs the fabric web is passed for shrinking, the endless springs of each set forming said adjacent runs converging toward the center in the direction of travel of the fabric web therebetween, a plurality of rollers for mounting the endless springs of each set, said rollers being arranged along the direction of travel of the fabric web and in contact with said adjacent runs of each set of endless springs, and means for driving said rollers at progressively slower speeds in the'direction of travel of said fabric web thereby to effect a corresponding progressive contraction of said adjacent runs of said sets of converging endless springs and thereby to condense said fabric web simultaneously in the longitudinal and transverse directions thereof.

4. Apparatus as defined in claim 3 for shrinking aknitted fabric web wherein each of said rollers is provided with a series of grooves individual to the endless springs of each set, the grooves on the rollers located at the position where said fabric web enters between adjacent runs of said sets of endless springs being located farther apart than the grooves on the rollers located at the position where said fabric web leaves the adjacent runs'of said sets of endless springs thereby to effect said convergence of the endless springs of each set.

a web of knitted fabric and which further includes a housing in which said sets of endless helical springs are contained, and means for generating steam in said housing.

6. In an apparatus for shrinking a web of knitted fabric, a pair of webs of endless helical springs having adjacent runs disposed in web feeding relation and between which runs the fabric web is passed for shrinking, the helical springs of each web being spaced apart and extending longitudinally in the direction of travel of thefabric web, a plurality of rollers for mounting the endless springs of each web, said rollers being arranged along the direction of travel of the fabric web and being in contact with thesaid adjacent runs of each Web of endless springs, and'means for driving the said rollers at progressively slower speeds in the direction of travel of the said fabric webs thereby to effect a corresponding progressive contraction of the said adjacent runs of the said webs of endless springs and thereby to condense the said fabric web.

7. A method of shrinking knitted fabrics characterized in that the knitted fabric is introduced between and carried through two longitudinally moving webs of helical springs extending in the direction of movement thereof, said spring webs being progressively contracted in the direction of movement thereof and of said knitted fabric and said spring webs likewise becoming progressivelynarrow by convergence of the springs forming the same in the direction of movement thereof and of said knitted fabric, whereby said fabric iscompressed simultaneously in' the longitudinal and transverse directions thereof respectively as it is carried through said spring webs.

References Cited in the file of this patent UNITED STATES PATENTS 1,982,720 Woodhead Dec. 4,- 1934 1,988,376 De Smet Jan. 15, 1935 2,171,551 Hannig Sept. 5, 1939 2,262,268 Chatfield NOV. 11, 1941' FOREIGN PATENTS 704,813 Germany Apr. 7, 1941

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