CA1036380A - Tubular knit seamless stocking - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A tubular knit seamless stocking has boot, heel, instep and toe portions formed of non-elastomeric yarn, incorporating, substantially throughout, at least one elastomeric stretchable retractive yarn having the major portion thereof inlaid coursewise of, and locked in, said portions.
The toe portion is formed primarily of non-elastomeric yarn and is free from elastomeric stretchable retractive yarn. The non-elastomeric yarn may be stretch or torque yarn of s and z twist. The heel and toe portions each include a shaped pocket knit of non-elastomeric yarn including partial courses successively varying in length, the cut ends of yarn of each partial course being knit in tuck-float relationship with a stitch loop of an adjacent course to prevent pulling out. The toe portion further includes a toe inspection opening including a welt of doubled stretchable elastic fabric incorporating elastomeric stretchable retractive yarn and having transferred stitches providing the doubled fabric welt. It may have a run resistant tab portion extending beyond the transferred stitches.

Description

~0363E~0 This invention is concerned with tubular knit seamless therapeutic stockings and more particularly to the foot construction thereof. This application is a division of Canadian patent application Serial No. 215,338 filed December 5, 1974.
The foot construction of therapeutic stockings is beset with a number of problems arising, for example, from the necessity of maintain-ing the stocking in pos tion, while achieving comfortable fit and the desired pressure distribution, and usually of providing an inspection toe opening as well, and of doing this at reasonable cost.
Therapeutic stockings knitted on machines with reciprocating cylinders usually contain non-elastic heel and toe pockets. The knitting of these heel and toe pockets is very time consuming and therefore more costly. Multifeed tube type hosiery machines are more efficient and less costly to operate but they are not constructed to provide reciprocated heel and toe pockets. It is therefore necessary to devise other means to produce shaped, form-fitting heel and toe pockets.
It is a major object of this invention to provide a therapeutic stocking having a novel foot construction which satisfies the desired criteria and to do so more efficiently.
Accordingly, the tubular knit seamless stocking of the invention has a toe portion including a shaped toe pocket knit including partial courses successively varying in length, the yarn in each successive partial course being cut at opposite ends, and the yarn of each partial course being knit in tuck-float relationship with at least one stitch loop of an -immediately adjacent course to prevent pulling out of the cut ends of yarn, and including a toe inspection opening adjacent the shaped toe pocket, the toe inspection opening including a welt of doubled stretchable elastic fabric incorporating elastomeric stretchable retractive yarn, at least one course of the welt having transferred stitches providing the doubled fabric welt.

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^, ' , . ' ~03~3~30 Special features can be provid0d through the utilization of vary-ing stitch densities and by supplying different amounts of elastomeric and non-elastomeric stretch yarn throughout the stocking or other leg and foot garment to provide the desired amount of support in each particular leg and foot section.
Therapeutic stockings can provide specific amounts of compression on the human leg when worn by patients. This compression is produced by combining the specific stitch density in each stocking section with specific amounts of non-elastomeric stretch yarn with elastomeric inlay yarn. It differs in the upper thigh, lower thigh, knee, calf, ankle, the graduated instep, and the foot portions.
The toe portion is preferably formed of fine stretch non-elastomeric doubled yarn of s and z twist and free from elastomeric stretchable retractive yarn.
For the purpose of fully describing the invention, reference is now made to the following detailed description of a preferred embodi- `
ment thereof, together with the accompanying drawings.
In the drawings, ;;~ , Fig. 1 is a diagrammatic side view of a therapeutic stocking having incorporated therein the toe construction of the invention; `~
Figs. 2 through 5 illustrate fabric structures used in various portions of the stocking of Fig. l;
Fig. 6 is a sectional detail vi`ew of a portion of the stocking of Fig. l; and Figs. 7 through 9 illustrate cam ring layouts for manufacturing the stocking of Fig. 1.
Referring first to Fig. 1, a tubular knit seamless therapeutic stocking is shown generally to include a boot and foot portion 11 and 12, a heel portion 14, a stitch graduated instep portion 13 and a toe portion 18.

; ~; : - . , .. : " ` ": ' 1036~80 As shown in Fig, 2, boot and foot portion ll and 12 and stitch graduated instep portion 13 are formed primarily of fine non-elastomeric stretch yarn, such as 70/l nylon torque yarn or the like, of s twist 22 and z twist 24 alternately knitted in every course of said portion. In order to provide the desired retractive force, there is also incorporated substantially throughout the boot and instep portions elastomeric stretchable and retractive yarn 26 such as 280 denier nylon covered spandex defining the relaxed shape of said boot and instep portions and having the major portion thereof inlaid coursewise of, and, interlaced to lock in, said knitted boot and instep portions at frequent intervals in every course in which it occurs. ~ ;
The stretchable and retractive yarn 26 is provided in sufficient courses of the said boot and instep portions, herein shown as in every two courses, so that when said portions are in a stretched condition around the corresponding part of the human form of different diameters, it exerts the desired compressive force.
Elasticized, shaped or form fitted heel and toe pockets consisting of extra partial courses are particularly useful in stockings of tubular ~ -construction such as hospital, surgical, and support stockings, A typical example of a heel structure is shown in United States Patent No. 3,241,340 dated March 22, 1966 to Herbert Knohl. The flexing and stretching of these garments in actual use makes the trimmed ends of the necessary partial courses of stretch yarn particularly vulnerable to withdrawal from the last knitted stitches, resulting in runs in the margin area of the heel and toe pockets, It is advisable, therefore, to provide several safety stitches at the terminal points of the partial courses to prevent these runs. This can be accomplished by knitting several tuck stitches or combinations of tuck and float stitches at the terminal points of the partial courses of heel and toe pockets. Typical examples are shown in United States Patent Nos. 3,603,116 dated September 7, 1971 to Francesco Turini and 3,181,314 dated May 4, 1965 to John J. Millar. The terminal points of the partial courses can be :,'''' ~ ~ .

arranged to occur in a straight line or in a contoured manner depending mainly on the type of needle controls built into the hosiery machine used As shown in Figure 3, heel portion 14 is also formed primarily of fine stretch torque yarn, of s twist 22 and z twist 24 alternately knitted in every course of said portion. It also incorporates, substantially throughout heel portion 14, elastomeric stretchable and retractive yarn 26, such as 280 denier nylon-covered spandex, defining the relaxed shape of said heel portion and having the major portion thereof inlaid coursewise of and interlaced to lock in said knitted heel portion at frequent intervals in every course in which it occurs. The stretchable and retractive yarn is again provided in sufficient courses, herein shown as in every two courses, so that when heel portion 14 is in a stretched condition around the heel, it exerts the desired compressive force.
Heel portion 14 includes a shaped heel pocket 15 which, in addition to non-elastomeric, stretch nylon yarns 22 and 24 and elastomeric yarns 26, is knit of fine non-elastomeric stretch 70/2 doubled s and z nylon superloft yarn 28 in partial courses successively varying in length. The yarn 28 of each successive partial course is cut at opposite ends and is knit in tuck-float relationship with at least one stitch loop of an immediately adjacent course, to prevent pulling out of the cut ends of yarn, this being disclosed, for example in Patent Nos. 3,241,340 dated March 22, 1966 to Herbert Knohl and 3,603,116 dated September 7, 1971. Also, adjacent courses of elastomeric yarn 26 are separated in the convex heel pocket 15 by two partial courses of yarn 28 forming less than a complete circumferential round of the stocking.
The heel transition area 16 shown in Figure I is that area within which the cut ends of the partial courses terminate. Elastomeric yarn 26 is preferably present in greater amount in the rounds closely adjacent said pocket, as disclosed in Patent No. 3,241,340.
As shown in Fig. 4 the toe portion 18 is formed primarily of fine stretch non-elastomeric yarn 23, such as 40/2 doubled s and z nylon superloft :
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:10363t30 yarn knitted in every course of said portion but, unlike tlle knitted structure thereabove, is free from elastomeric stretchable retractive yarn, the line of demarcation therebetween appearing at 17 in Fig. 1. In the toe portion then, the stretch yarn 23 is relied upon primarily for coverage, when said toe portion is in a stretched condition around the corresponding part of the human foot. Toe portion 18 includes a shaped toe pocket 19 knit entirely of non-elastomeric but stretch 40/2 doubled s and z nylon superloft yarn 28 which, in addition to nylon yarn 23, is in partial courses successively varying in length. The yarn 28 in each successive partial course is cut at opposite ends and is knit in tuck-float relationship with at least one stitch loop of an immediately adjacent course, to prevent pulling out of the cut -ends of yarn, as with heel pocket 15.
Toe portion 18 terminates in a toe inspection opening adjacent shaped toe pocket 19 either above or below it, said toe inspection opening being defined by a welt 21, shown in detail in Figs. 5 and 6 of doubled stretchable elastic fabric incorporating elastomeric stretchable retractive yarn 28, in addition to stretch yarn 23. The elastomeric yarn is knit in a 1:3 knit-float construction as in Fig.5 and should be either a high stretch covered elastomer or bare spandex so as to form a very tight, controlled opening. One course of said welt has transferred stitches at 30 providing said doubled fabric welt with its looped end 32. A run resistant tab portion 34 is provided extending beyond said transferred stitches 30.
The above-described seamless therapeutic stocking is made on a continuously rotating cylinder knitting machine, specifically, the Zodiac 4F, manufactured by Billi S.p.a. Firenze Costruzione Macchine Tessili, of Italy, such machine being previously known and used in United States and having been described in an English Language training manuai which has been available in the United States since at least as early as September, 1973.
Using this machine, with a 4-inch 401-needle cylinder and equipped witn an elastomeric thread furnishing device, such as described in United . ;
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~036380 States Patent No. 3,209,558 dated October 5, 1965 to James T, Cargill, knitting is begun at the top of the stocking in the usual manner with two knitting feeds, one of s twist non-elastomeric stretch 70/1 nylon torque yarn and the other of z twist non-elastomeric stretch 70/1 nylon torque yarn, and one inlay feed of elastomeric yarn such as 280 denier nylon covered spandex. The fourth available feeding station is not in use. The stitch size is controlled throughout the garment from the usual stitch control system incorporated in the machine and the elastomeric yarn is metered into the machine at a predetermined rate throughout the leg, instep, and foot portions. The fourth feed is activated in the heel pocket area to knit the partial courses including the terminal safety stitches. The cam ring layout, Figure 7, shows a typical needle selecting system for a heel structure of this type. The cam segment AD in the needle butt race can be altered to permit completely independent movement of cam segments AD and AE to produce knitted tuck or float structures particularly at the terminal points of the partial courses used to form the heel pocket. Needle selection for each feed is accomplished in the usual manner from the pattern drums in the lower portion of the selector jacks or in the center section from the slide system - acting on the selector jacks. The selection is transmitted to the intermediate jacks and from there to the needle butts. The heel portion is further rendered more desirable by the adaptation of the fashioning of the instep area described in United States Patent No. 3,443,404 dated May 13, 1969 to Herbert Knohl.
The partial courses of the heel area are eliminated in the foot section which is knitted in the same manner as the leg portion of the stocking with two knitting feeds and one inlay feed. A reinforcing yarn or an absorbent yarn can be provided in the foot area by using this yarn as extra courses or as superimposed or plated stocking sections under the foot area.
At this point, all of the elastomeric yarns are taken out of , .. .

~ ' ' , ` ' ' ' ' lV3f~380 action and stretch nylon yarn such as 40/2 nylon superloft yarn introduced on all feeding stations. The toe pocket described can be knitted on 4, 6, 8 or even 12 feed hosiery machines provided they are equipped with special needle controls on all knitting feeds, On a 4-feed machine, one can knit with all feeds knitting over the toe area and with only one knitting feed under the foot or toe area. Three of the feeds knitting over the toe area produce partial courses while the one feed under the toe area produces knitted courses on all needles in the cylinder. Automatic trimming devices cut the loose ends of the partial courses to a prescribed length and by repeating this procedure for a number of rounds of the needle cylinder, a rounded toe pocket is formed on the knitting machine.
The toe fabric consists of three sections.
a. Ring Toe I - 4 feeds all nylon knitting on all needles (Area 36 of toe portion 18).
b. Toe Fashioning - l feed knits on all needles 360 = 401 needles 1 feed knits on 205 needles at 42.
1 feed knits on 170 needles at 44.
1 feed knits on 134 needles at 46.
c. Ring Toe II - 4 feeds all stretch nylon knitting on all needles ~`
~Area 38 of toe portion 18).
The needle movement of the toe pocket shown in the cam ring layout Fig. 8 is as follows:
Feed number 3 knits on every needle each revolution of the cylinder while feeds number 1, 2 and 4 knit only partial courses on selected needle groups in the cylinder. Each partial course starts and ends with a series of tuck and float stitches (2 - 6) to lock the terminal ends of the partial courses into the fabric and avoid runs and failures when the garment is in use.
While it is feasible to introduce the partial courses on the same , ' ,~, , ~ . .
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10363~0 needles, it is generally preferred to introduce partial courses at different needle groups in order to obtain a better, more wrinkle-free appearance of the toe pocket and avoid faulty trimmer action due to bunching of the terminal ends during the mechanical trimming operation.
The needle selection for the partial courses is initiated from slides R to X in the pattern drum control area and slide E in the slide control area.
Feed number 3 obtains its needle selection from cam segments AE
and AD in the needle butt race. The needles in feed number 4 are activated from slides U to X in the pattern drum section of the selector jacks. The selection is transmitted to segment M of the intermediate jack race. The segment AA is withdrawn slightly to produce one cam elevation at tuck height and another elevation at clear height. The cam segments AE and AD in the needle race are withdrawn on feeds number 1 and 4.
The needles in feed number 4 are activiated from slides U to X in the pattern drum section of the selector jacks. The selection is transmitted to segment AA of the intermediate jack race. Segment AA is withdrawn slightly to elevate the needles in the main panel of partial courses to clear height and the needles in the terminal areas on both sides of the main panel to tuck height. The float needles between the tuck needles are not selected.
Feed number 4 produces the shortest length of partial courses in the toe area.
The needles in feed number 1 are activated from slides U to X in the pattern drum section of the selector jacks as well as slide E in the selector jack slide section. The needle selection made in feed number 4 is transferred through intermediate jack cam segment AB which is partially withdrawn.
The needles selected by pattern drum slides U to X and the needles selected by selector slide E are raised to clear height by intermediate jack segment AB. Some of the needles in the terminal areas are raised to ~uck ., :
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height through the use of intermediate jacks with extra short butts, Non- `
selected jacks in the terminal area produce the float. Feed number 1 produces the intermediate length of partial courses in the toe area.
The needles in feed number 2 are activated from slides R to X of the pattern drum section of the selector jacks. This selection is transmitted to segment AA of the intermediate jack race. This segment has been altered and the selected intermediate jacks are raising the needles to clear height.
Needle selecting segment AD is activated, but partially retracted to provide the tuck stitches on long butt needles in the terminal areas of the partial courses and the non-selected needles between the tuck stitches produce the float stitches. Feed number 2 produces the largest area covered by the partial courses in the toe area.
In a 4-feed machine, the radius of the toe fabric depends on the number of extra courses chosen for the toe pocket. The ratio of courses is ~` 4 above the toes and 1 below the toes while on 8-feed machines, the ratio could be 8 to 1, Functional automatic toe pockets can be formed with either ; system.
; The ring toe (I ~ II) areas 36 and 38 represent approximately 24 courses and the shaped toe area therebetween about 50 revolutions of the ~ 20 cylinder. At this point, the machine is programmed to produce the elasticized ~ -- toe welt section of the stocking, The final operation of the machine calls ; for the knitting of an automatic elasticized welt including a makeup, transfer, and a number of anti-run courses.
; The make-up and transfer are knitted in the usual manner by dividing the needles and producing a knit-float relationship between adjacent needle groups and placing the transfer bits in the position of the floating needles (odd needles). This deposits a knitting yarn on the transfer bits which is held until the welt fabric has been knitted. This make-up procedure is -produced on one feed only and is in action for one complete cylinder revolution. The remaining three feeds knit on all needles.
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' '.'`,:",' ' " ,, , : ,'~ ' ' The transfer is produced in a similar manner after the ~elt fabric ~as been knitted. The needles are divided again but this time the odd needles are raised to knitting position while the even needles are left in float positions. On the rise to knitting position, the odd needles advance through the openings provided in the transfer bits and take the loops deposited on the bits during the make-up operation.
The make-up and transfer operations are conventional.
The elasticized welt fabric knitted between the make-up and transfer operations differs slightly from previous descriptions, its cam ring layout being shown in Fig. 9. The welt fabric shown in Fig. 5 is knitted on four feeds with one of the feeds containing, in addition to the conventional knitting yarn, an elastic yarn incorporated in the fabric in a 1:3 knit-and-float selection.
The run-resistant welt tab 34 after the transfer can be knitted in various ways. It has been found that the procedure using three feeds produces the best results.
Feed #1: All needles knitting ~ -Feed #2: Knit-tuck on alternating needles and knit-float with bare spandex todd) Feed #3: Inactive Feed #4: Tuck-knit on alternating needles (even).
The degree of run resistance is affected materially by the stitch size drawn on each feed as well as the stitch type chosen. A run-resistant tab knitted with a density to produce about 9 inches of total stretch performs very well in the toe tab.
While the inspection toe opening has been shown to be located under the foot, it can obviously be placed above the base of the toes.
While the usual procedure calls for the knitting of the stocking 1~)36380 from the thigh to the toe, it is equally appropriate to start the stocking at the automatic inspection toe opening and knit from toe to thigh. In this case, a run-resistant toe tab prior to the elastic welt becomes unnecessary, but the machine will have to be modified to knit with a higher stitch density at the beginning of the stocking, the ankle and foot area, and a lower stitch density at the thigh area. The final courses in the upper thigh area should contain several courses of an anti-ravel yarn or anti-ravel stitch formations to permit the usual processing.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A tubular knit seamless stocking having a toe portion including a shaped toe pocket knit including partial courses successively varying in length, the yarn in each successive partial course being cut at opposite ends, and the yarn of each partial course being knit in tuck-float relationship with at least one stitch loop of an immediately adjacent course to prevent pulling out of the cut ends of yarn, and including a toe inspection opening adjacent the shaped toe pocket, the toe inspection opening including a welt of doubled stretchable elastic fabric incorporating elastomeric stretchable retractive yarn, at least one course of the welt having transferred stitches providing the doubled fabric welt.

2. A tubular knit seamless stocking as claimed in Claim 1 wherein the toe portion is formed primarily of fine stretch doubled non-elastomeric yarn of s and z twist and free from elastomeric stretchable retractive yarn.