US2672139A

US2672139A - Elastic surgical stocking

Info

Publication number: US2672139A
Application number: US140626A
Authority: US
Inventors: Caspar Frank Albert
Original assignee: PAK PARACHUTE Co Ltd
Current assignee: PAK PARACHUTE Co Ltd
Priority date: 1949-07-27
Filing date: 1950-01-26
Publication date: 1954-03-16
Anticipated expiration: 1971-03-16

Description

March 1954 F. A. cAsPAR 2,672,139 ELASTIGE SURGICAL STOCKING Filed Jan. 26, 1950 2 Sheets-Sheet 1 lnyentor FKA NK ALFEKT CAS 194K F. A. CASFAR ELASTIC SURGICAL STOCKING March 16, 1954 2 Sheets-Sheet 2 Filed Jan. 26, 1950 544401 4364?! GAS A6 8 M m Attorney Patented Mar. 16, 1954 ELASTIC SURGICAL STOCKING Frank Albert Caspar, Redruth, England, assignor to Pak Parachute Company Limited, Redruth, England, a British company Application January 26, 1950, Serial No. 140,626

Claims priority, application Great Britain July 27, 1949 6 Claims. (Cl. 128-165) The invention relates to elastic surgical stockings which are employed in the treatment of varicose veins and other disorders.

The essential requirements of such an elastic stocking are that it should produce an even pressure over the leg when in position, that it should not interfere with circulation of air over the skin, and that its ccefiicient of friction over the skin should be low. A further desirable quality is that the seams should not be of excessive thickness.

Previous constructions of elastic stockings have not attained these requirements entirely, since they have included in their construction an amount of rubber which contacted the skin and created excessive friction and prevented equalisation of pressure over the leg. Also the amount of rubber in contact with the skin reduced circulation of air. The seams in previous constructions have also been excessively thick and lacking in elasticity.

The main object of the present invention is to provide a stocking having the above mentioned essential requirements. A further object of the present invention is to provide a simple method of making a stocking. A still further object of the invention is to provide a simple method of making an elastic surgical stocking from two pieces of elastic material. A still further object of the invention is to provide a novel way of hemming and joining the two-way stretch material in a surgical stocking to provide a seam of substantially the same thickness and elasticity as the material.

In the drawings:

Fig. 1 shows a piece of an example of two-way stretch lace net in an unstretched condition to an enlarged scale.

Fig. 2 shows an enlarged view of the same piece of material having tension applied across the warp threads,

Fig. 3 shows diagrammatically in elevation and cross-section the formation of a hem or seam, the weft threads being omitted for simplicity,

Fig. 4 shows a cross-section on line 4-4 of Figure 3,

Figs. 5 and 6 show the shapes of the pieces of material to make the surgical stocking, and

Figs. 7 and 8 show two elevations of the completed stocking, as viewed from the side and from the rear, respectively.

I An example of the material employed is shown more particularly in Figures '1 and 2 and comprises elastic warp threads in with the weft threads spun in position on the warp. The warp threads are elastic strands covered by silk, synpair containing one thetic substitutes for silk and/or cotton, and the weft threads are yarn of silk, synthetic substitutes for silk, and/or cotton. It will be noted that in the unstretched position each weft thread encircles each warp thread once. It will also be noted that there are two sets of weft threads, those marked Ha which follow a general direction downwardly to the left and those marked i In which follow a general direction downwardly to the right, and that weft threads pass between adjacent warp threads in crossed pairs l2, each thread i la and one thread I I b. Two-way stretch action is illustrated more particularly by Figure 2 where a tension has been applied to the material at right angles to the warp threads Iii. It will be noted that the warp threads have assumed a wave formation due to the staggered arrangement of the cross pairs l2 of weft thread on opposite sides of each warp thread. As a result of the wave formation of the warp threads, it will be appreciated that they have increased in length and therefore are in elastic tension along their length. It will be seen that this tension results from the application of a tension at right angles to the warp and also that the elasticity of warp threads IE) allows the material to stretch in directions along the warp threads and at right angles to the warp threads. It will also be obvious that tension applied to the material in one direction will produce a corresponding increase in tension and/or reduction in length in a direction at right angles thereto. The fact that the weft threads are twisted or wound around each warp thread of the above described net material ensures that the material will not run or unravel when it is cut as hereinafter set forth.

Surgical stockings made from this material will have all the desired characteristics. Relatively low friction with the skin is a result of all the material coming into contact with the skin, being only of silk or synthetic substitutes therefor, or cotton. Ewenness of pressure results from a combination of the two-way stretch and elasticity such, for example, as the calf around which the stocking is normally tensioned, causing contraction of the material along the leg (movement being facilitated by the relatively low friction) and. consequent contraction and tensioning of the stocking around the ankle. Circulation of air over the skin is impeded only to a very small degree, since the material is in fact a net.

In order to make a surgical stocking very simply to individual measurements from sheet twoway stretch lace net, two pieces of the material to suit the individuals measurements are cut out as shown in Figures 5 and 6. The leg 01' first piece shown in Figure 5 is formed with a major part having a wide upper portion I 5 to surround the calf of the leg and a narrow portion [5 to surround the ankle and a narrow extension IE to cover the top of the foot. The first piece is further formed so that portions of the end edge of the narrow portion iii are contiguous to the side edges of the extension [6. The foot or second piece is shown in Figure 6 and comprises a lower tapering portion H to cover the sole of the foot and two extensions [8 at one end enclosing a U-shaped recess E9. The first and second pieces of Figs. 5 and 6, respectively, are formed so that the side edges and 2| of the respective pieces extend substantially at right angles to the directions of the elastic warp threads of the material from which the pieces are cut or formed.

In the construction of the stocking from these two parts, the side edges 20 of the calf and ankle portions l4 and iii are connected together by stitching to form the complete leg portion. The end edges of the extension !8 are connected together by stitching so that the recess 59 forms a hole through which the heel projects. The side edges 2| of the foot piece are then secured by stitching to the side edges of the extension 15 and the contiguous end edge portions of the major part, indicated by the reference numerals 22, to form the foot of the stocking. The toe and the heel are left open as is usual in surgical stockings, since these are the places which would receive the heaviest wear.

For securing the parts together by stitching, the method as illustrated in Figures 3 and 4 isvadapted with the object of allowing the seam to stretch along its length whilst at the same time not forming an objectionably thick portion. The edges of the material shown are turned back on themselves or reverted for a short distance, the ends 24 of the warp threads I!) settling between the actual warp threads. The folded or reverted edges are placed in close edge-to-edge proximity to one another and are then stitched together by a fiat-lock or similar sewing machine which automatically lays a thread 25 across the gap in a zig-zag manner and secures the thread 25 at each side of the gap by means of stitching 26 extending in a direction parallel to the gap. The stitching 2B is arranged to be of such spacing so that each stitch embraces one warp thread and the turned-back end 24 of one adjacent warp thread. Thus, when the stocking is stretched along a seam, the thread 25 will open up or be extensible in the direction along the seam and the threads 25 will compress or squeeze their enclosed elastic warp threads. In the case where a seam actually runs parallel to the elastic warp threads, the stitching 26 will run in between adjacent warp threads, and the parts of the threads 25 on one side of the gap locked by stitching 26 will embrace at least four warp threads so that again stretching the seam along the warp will cause stitching 26 to compress the enclosed warp threads.

The strength of such a seam is due to sewing together on a bight (the turned back thread 24) the bight making it impossible for the thread to pull out of the seam. The settling of the turned back portion 24 of the threads between the actual threads ensure that the seam is actually very little thicker than the material of the stocking. The elastic net described in actual practice has spaces between the elastic warp threads. at least as large as the diameter of the warp threads so that the turned-back ends 24 may settle easily between the warp threads.

The upper edge of the stocking and the edges of the heel and two holes are hemmed by folding back or reverting the edge of the material in the same manner as illustrated in Figure 4 for joining and sewing along with the flatlock or like machine so that the hem so formed is extendable in the same manner that a seam is extendable.

It will be appreciated that the surgical stockings described are made to individual measurement and i all cases the size of the completed stocking is such that it is slightly smaller than the leg it is to fit. The degree of tightness of each stocking may be adjusted by pulling the stocking further up the leg and over the calf, and the increased tension is transmitted almost equally to all parts of the stocking.

I claim:

1. An elastic surgical stocking of the class described; comprising a first piece cut from a sheet of two-way stretch lace net material and including a major part shaped to provide a calf and ankle covering portion and an extension at one end of said major part formed to provide an upper part of a foot covering portion, the end edge of said major part at the end of the latter adjacent said extension having portions contiguous to the side edges of said extension, a second piece also out from said sheet and shaped to provide a lower part of the foot covering portion, and stitching securing together the side edges of said major part of the first piece to provide a rear seam and securing the side edges of said second piece to the side edges of said extension and the contiguous end edge portions of said major part of the first piece to provide seams at the opposite sides of the foot covering portion, said stitching being extensible along the lengths of the respective seams.

2. An elastic surgical stocking according to claim 1; wherein said stitching includes zig-zag threads secured across the adjacent edges joined by said stitching.

3. An elastic surgical stocking according to claim 1; wherein said second piece has spaced apart longitudinal extensions at one end thereof defining a U-shaped extension therebetween, stitching securing together the end edges of said extensions of the second piece, and said second piece being secured to said first piece with the stitched together end edges of said extensions of the second piece in alignment with, and forming a continuation of, said rear seam so that said recess provides a heel-hole.

4. An elastic surgical stocking according to claim 1; wherein said two-way stretch lace net material includes elastic warp threads and two sets of weft threads oppositely inclined with respect to said warp threads, each of the weft threads encircling each warp thread that it passes.

5. An elastic surgical stocking according to claim 4; wherein said first and second pieces are cut from said sheet so that the side edges of said pieces are substantially at right angles to said elastic warp threads.

6. An elastic surgical stocking according to claim 5; whereing the side edges of said first and second pieces along which seams are formed are reverted with the turned back portions of said warp threads being positioned between adjacent warp threads; and wherein said stitching includes zig-zag threads extending between and overlying the turned back portions of the secured together edges, and threads extending parallel to each of the secured together edges and through said zig-zag threads, said threads parallel to the secured together edges passing alternately above and below said turned back portions of the warp threads and the adjacent warp threads to secure said zig-zag threads to the secured together edges.

FRANK ALBERT CASPAR.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Picot Oct. 25, 1892 Cartledge Dec. 27, 1898 Ware Aug. 26, 1902 Price Mar. 23, 1928 Prazak Jan. 12, 1937 I-Iinchlift Aug. 8, 1939 Brown July 31, 1945 FOREIGN PATENTS Country Date Great Britain 1904 Switzerland Aug. 1, 1929