US2641004A - Method for producing knitted shoe uppers of shrinkable yarn - Google Patents

Description

' D; v. WHiTlNG ETAL 2,641,004 METHOD FOR DUCING KNITTED SHOE UPPEFBSI SHRINKABLE YARN ed Dec. ,26, 1950 June 9, 1953 3nnentors DAV/D V. WH/T/A/G JOHN .5 U/VV4/V (Itlomeg ing the same. In any case, the result sought is a generally conventional soft sock form that has a substantially whole bottom or sole.

The sock thus produced is made considerably larger in size than the size to which the same is to be shrunk, but is not necessarily made in the full range of sizes in which shoes are made. At present, it is contemplated that four basic sock sizes will provide uppers which are usable over the complete range of stock shoe sizes. The last [6 over which the sock I is shrunk controls the size of the upper that is produced.

The considerably larger sock is pulled over last l6. However, before this is done, an insole I1 is positioned against the bottom of the last substantially as shown. The sock is then adjusted and centered on the last and the extension portion I3 is pulled, with reasonable tautness, to make the sock conform to the contours of the last. The excess of material above the last is bunched and tied in the manner suggested in the drawing. The opening I5 may be spanned by synthetic threads or bunched or gathered in the manner of portion it.

The lasted sock is then subjected to a shrinking step which is suggested in Fig. 3 wherein a closed receptacle I 8 encloses the sock and retains the same for a period of time in an atmosphere of heat. A steam inlet l9 supplies dry or wet steam, as desired, to the receptacle and the heat thereof is effective to shrink the sock tightly around the last, the fibers hardening in the process from their initial soft condition to a hard yet elastic condition. Other heating methods may be used, the same being chemical reaction, open flame, hot or boiling water, etc. In any case, the intent is to activate the synthetic fibers to cause them to retract or relax and, thereby, draw the knitted fabric upper tightly around the form of the last. The time of the heating step may vary according to proportion of the initial size of the sock and the shrunk size and according to the medium employed to effect shrinking. A minute or so is sufficient when steam is used and the shrinking is moderate. Longer time is used where greater shrinking is involved. By employing a heat medium that is of higher temperature, as between 212 and 250 F., the fibers set and retain the set form unless subjected to higher temperatures. under normal conditions.

The degree of shrink in any direction may be controlled as desired by knitting a sock in which The latter is unlikely, of course,

inside of the sock or from the outside thereof,

as desired.

After a few minutesfive or ten-or when the lasted sock is cool enough to handle, the extension portion [3 is removed. As shown in Fig. l, the last [6 may be provided with a guide groove 20 along which a cutter effects severance of portion l3 from the ultimate upper II. If desired, the last may terminate along the line of groove 20, in which case, the top of the last will serve to guide a severing cutter.

The upper thus provided may then be relasted or left on last I6 and the heel and sole 4| is applied in the usual manner by pasting, cementing, or nailing, as the case may be.

The shoe is now complete except for providing a finish for the contour edge of the upper. As shown in Fig. 4, said edge may be seared with a heated tool to fuse the fibers of the yarn along the severance line to coagulate the same and form a finishing bead 2|. This may be done before or after removal of the shoe from the last. Fig. 5 shows another edge-finishing method, the same entailin the application of a binding 22 by stitching, cementing or pasting the same in place. Since binding-applying machines are available, the latter edge-finishing step can be effectively accomplished.

As shown in Fig. 2, if open-toed uppers are desired, the sock is knitted with an open extension 23 at the toe, similar to but smaller than extension I3. In other respects, the shoe is processed as above described except that said extension 23 is severed from the upper as guided by a groove 24 provided in the last. The edge thus formed at the upper toe is bound as suggested in Figs. 4 and 5.

Another way of achieving a finished edge along the upper edge of the upper is shown in Figs. 3, 6 and '7. In this case the sock extension l3 may be materially reduced in length with the result that considerable material is conserved. As shown, the extension 25 is relatively short, being only long enough to enable folding the upper around a tightly applied binding cord or tape 26. This is expedited by providing the last I6 with a downwardly facing shoulder 2! as in Fig.6 or with a groove 28 as in Fig. 7, said shoulder or groove, as the case may be, retaining the cord along a desired top line. Now, the slack and soft materlal of the sock may be tucked in behind the cord to form a double fold 29 that spaces the cord from the last substantially as shown. The body of the sock, being much larger than last [6, is loosely draped thereover as shown in Fig. 3. Of course, the size of the sock, relative to the size of the last, is such that the initially slack sock body will shrink tightly over the last, and the size of the opening in upper l I such that the same is conformed to groove 28 by cord 26. If desired, tacks 36 or other suitable temporary means may be employed to center and align the loose sock on the last. The lasted sock is shrunk onto the last as hereinbef ore set forth.

The sock shrinks to the line of the top line as defined by cord 26 and after the last is removed, it is only a matter of trimming away the extension 25, as along a line 3|, to leave the upper with a properly finished top line. In Fig. 6, it will be seen that the finishing bead thus formed does not encroach on the shoe opening. While the bead of Fig. 7 does, the encroachment can be kept small by reducing the thickness of the cord.

From the method above disclosed, it will be seen that the shoe provided has an upper I l and a substantially complete bottom I2, which are integrally formed of a knitted fabric. It will be evident that such a shoe will be form-retaining and, thus, will resist deforming. The thermo-set fabric is stable under all normal conditions, imparting to the shoe strength desirable in such items. The various knitting methods enable incorporation of beauty-enhancing designs in the fabric at no additional cost, a great latitude of employment of open work, etc., being available to the designer.

Although the present invention has been described with respect to certain preferred methods, and steps thereof, it' will be realized that variations may be practiced without departing from the spirit and scope of the invention. Accordingly, we desire to reserve to ourselves such modifications that may fall within the scope of the appended claims.

Having thus described the invention, what we claim and desire to be secured by Letters Patent is:

l. The method of making a shoe upper which consists in providing a knitted soc}: that has a substantially complete bottom and an upper in tegral therewith, said bottom and upper being formed of pliable and soft synthetic thermo=setting resin yarn that has the property of shrinking when subjected to heat, mounting the sock on a last that is substantially smaller than the initial size of the body of the sock upper and bottom, confining the upper portion of said upper along a line around the upper portion of the last in a manner to leave the portion of the sock upper below said line and the sock bottom in slack con dition, applying heat to the sock to cause the slack portions of the same to shrink tightly onto the last below said line of confinement to change the sock from its initial soft and pliable larger condition to a smaller but stiffer pliable and References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,386,654 Pope W Aug. 9, 1921 1,910,251 Joha May 23, 1938 2,007,262 Tetlow July 9, 1935 2,314,098 McDonald Mar. 6, 1943 2,335,210 Guinzburg Nov. 23, 1943 2,435,797 Reed -1 Feb. 10, 1943 2,440,393 Clark Apr. 27, 1948 2,457,630 Beetson Dec. 28, 1940 FOREIGN PATENTS Number Country Date 12,786 Great Britain Nov. 26, 1908

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