US2853807A - Slip lasted shoe the parts of which are united by a single locally reinforced seam - Google Patents

Description

'Sept .30,1958 E QUINN 2,853,807

SLIP LASTED SHOE THE': PARTS OF WHICH ARE UNITED BY A SINGLE LOCALLY REINFORCED SEAM Original Filed July 29. 1954 .6706]? for Edward Quinn United States 7 2,853,807 Patented Sept. 30, 1958 SLIP LASTED SHOE THE PARTS OF WHICH ARE UNITED BY A SINGLE LOCALLY REINFORCED SEAM Edward Quinn, Saugus, Mass., assignor to United Shoe Machinery Corporation, Flemington, N. 3., a corporation of New Jersey Original application July 29, 1954, Serial No. 446,619. Divided and this application August 6, 1956, Serial No. 602,158

1 Claim. (Cl. 36-195) United States Letters Patent Serial No. 446,619, filed July 29, 1954, now Patent No. 2,807,224, granted September 24, 1957, of which this application is a division. In addition to the shoe construction, the parent application discloses a novel sewing machine particularly suitable for operating on slip-lasted shoes and a method of reinforcing seams of such shoes in areas subject to special stress. The method of the parent'application is the basis of a divisional application Serial No. 594,244, filed June 27, 1956. x

Since the size,-fit and durability of a slip-lasted shoe are determined entirely by the shape of the upper and sole blanks and the accuracy of the seam outline which connects them together, the desirability of reinforcing the seam'to prevent loosening or thread breakage in areas of special stress will be, immediately apparent. However, slip-lasted-construction is employed generally inlowerpriced shoes in which the cost of an extra seam reinforcing operation, performed after the insertion of the main seam, may be prohibitive. conventionally, slip-lasted shoes are machine sewn by a two-seam method. This method comprises first sewing together the sock lining which is an unchanneled blank in the form of a shoe sole and generally of relatively thin, woven material, and the upper blank by a first seam. The upper is manipulated by hand just ahead of the point of needle operation to bring the edges of the two parts into register, thus giving the upper the configuration of a shoe without using a last. The first seam is'directed' in close parallel relation with the edge of the sole and upper blanks. Thereafter, the platform cover strip which is generally of variable width is attached by a second seam which is usually not coincident with the first. A common practice is to insert the second seam parallel to and inside the first. Accordingly, any stress during wear is almost entirely on the' second-seam which also'determines the size and fit of the finished shoe.

A shoe having a single seam which connects the sock lining, upper blank, and platform cover is generally sewn on a machine particularly arranged for the purpose. Such a machine is disclosed in United States Letters Patent No. 2,722,182, granted November 1, 1955, upon an application filed in the names of Edward Quinn and Napoleon S. Ferland. In such a machine the sole and upper blanks are guided manually by the operator in much the same manner as is employed when inserting the first seam of a two-seam construction, but the machine is provided with a guide for automatically directing the platform cover strip into the sewing point in suitable edge register with the other parts to permit attachment by the single seam.

After the shoe parts have been sewn together, either by two scams or by a single scam, the shoe is applied to a last, and a platform sole is spotted on the lining. The cover is then wrapped around the edge of the platform sole, and the outsole is thereafter attached to the platform by a conventional means such as cement. When the platform sole includes a wedge-type heel it may be advantageous to employ a two-piece cover strip including a relatively narrow forepart piece and a wider heel piece. Itis customary to overlap the end portions of the two cover strip parts. When the cover strip is later wrapped about the platform, particular stress is placed on the stitches in the overlapped area. Other portions of the seam about the toe or heel may also be subject to special stress during wear of theshoe. Since the stitches are generally inserted with a small gage needle using relatively fine thread, the advantagesof reinforcing the scam in such areas of special stress will be readily apparent.

It is a general object of my invention to improve the construction and durability of slip-lasted shoes. Another object is to provide reinforcement of the size-determining seam of a slip-lasted shoe in an area subject to special stress. Still another object is to provide the desired reinforcement in such a shoe without adding a separate operation or significantly increasingits cost of manufacture.

In the achievement of the foregoing objects an important feature of my invention resides in a shoe construction having reinforcing stitches inserted with a continuous thread. This feature'not only provides a shoe having a stronger seam, but also simplifies the sewing operation. Another feature of my invention, which may substantially improve the over-all strength and durability of a slip-lasted shoe, consists in the use therein of a triplestitched reinforced portion of scam, the stitches of which are coincident. This feature is particularly important in shoes of certain materials which are sewn with short stitches. By making the reinforcing stitches coincident with those of the main scam the shoe parts are not objectionably perforated and weakened along the reinforced portions of the seam.

The foregoing and additional objects, features, and advantages of my invention will be more apparent from the following detailed description of an illustrative embodiment thereof, taken in connection with the accompanying drawings, in which:

Fig. 1 is a fragmentary view of pertinent parts of a slip-lasted shoe employing a connecting seam which is reinforced at points of special stress in accordance with my invention;

Fig. 2 is a diagrammatic representation of-one of the reinforced sections of the seam of Fig. 1; and

Fig. 3 is a detail view in side elevation taken from the left of a machine, on which the shoe of the present invention may conveniently be sewn.

Referring to Fig. l of the drawing, the parts of the shoe shown therein include an upper blank 2, a sole or sock lining blank 4, and a two-piece cover strip, the heel piece of which is indicated at 6, andthe forepart piece at 8. The upper, sock lining, and cover strip are connected by a single main seam 10. Reinforcing stitches in the seam are indicated at 12 in an area in which the forepart piece 8 and the heel piece 6 overlap.

In sewing a slip-lasted shoe constructed with a single seam connecting the upper, sock lining, and cover strip it is common practice to attach one cover strip piece, as for instance, the forepart piece 8, while sewing the toe portion of a shoe, and then while entering the shank of the shoe to introduce-the heel strip piece 6 to the sewing point in the machine. The sewing operation is then continued around the shoe until the last attached cover piece is brought into overlapping relationship with the cover piece first attached to the shoe. After the shoe has been sewn it is applied to a last, and-the platform sole is spotted on the sock lining. The cover pieces are wrapped around the edge of the platform sole to give the shoe an accurate configuration. Afterthe cover pieces have been wrapped about the edge of'theplatform sole those stitches of the connecting seam at the joints between the two cover pieces are subjected to greater stress than the remaining stitches. For this reason it is desirable to reinforce the seam connecting the overlapping end edges of the cover pieces or elsewhere in the shoe construction by inserting coincident reinforcing stitches.

The manner in which the reinforcing stitches are inserted according to this invention enables them to be formed without break in the thread. In Fig. 2, which shows diagrammatically a reinforced portion of the seam, the upper line of stitches represents the continuation of the main seam inserted while feeding the work in the direction of the arrows from right to left before reinforcement is effected. At the completion of the last stitch of the main seam 10 at the right of the upper line the direction of feed is reversed, as indicated by the other arrows, for inserting the additional reinforcing stitches 12 shown in the second line. After the stitch at the left end of the second line is completed, feeding is resumed in the original direction to provide additional reinforcing stitches -12 of the third line, and the seam is continued out of the reinforced portion. It will be understood that the three portions of the seam comprising stitches inserted as a continuation of the main seam, as a reversal, and as a resumption, although shown for clarity in spaced relation, are coincident, and the two additional overlapping portions 12 have holes in common with those of the main seam, through which common holes the thread of the three portions of the seam enters the shoe parts, as represented by vertical lines 14. Coincidence of the stitches is conveniently obtained by a novel feed control device in the machine of prior application Serial No. 446,619.

The machine referred to above, shown fragmentarily in Fig. 3, is of the lock stitch type and includes conventional stitch-forming and feeding devices. Briefly, these devices include a fixed work support 16, an eyepointed needle 18, a work-feeding presser foot 20, and a work-clamping presser foot 22. A feed dog 23 cooperates with the work-feeding presser foot to feed the shoe parts which are retained during part of the sewing cycle by the work-clamping presser foot 22 against the support 16.

To enable the overlapping reinforcing stitches 12 to be inserted most conveniently with the best results, the machine of Fig. 3 is equipped with a feed mechanism arranged to be operated selectively to cause the shoe parts to be fed in a forward or reverse direction. By reason of the manner in which the reinforcing stitches are inserted it is unnecessary to remove the shoe from the machine or to trim any threads between the main and reinforcing portions of the seam. Thus, the sewing operation may be resumed directlyafter inserting the reinforcing stitches without loss of time, and the edges of the shoe parts are united by a single continuous seam with three coincident portions, each reinforcing portion crossing the edges of the parts sewn.

p The cover strip pieces 6 and... 8 are, advantageously directed by a cover strip pilot mounted in advance of the sewing point on the machine. The cover strip pilot corresponds to that disclosed in Patent No. 2,722,182 and includes a bracket 24 secured to the support 15, a pilot roll 26 rotatable on an axis 28 afiixed on the bracket 24, and a roll 30 rotatably supported on a spring-pressed carrier 32. By spring pressure the carrier 32 bings the roll 30 into clamping engagement with the platform cover and presses the latter against the periphery of the pilot roll 26 The bracket 32 is pivoted through control means more fully described in application Serial No. 466,619 for engaging and releasing the platform cover strip. In the release position as shown in Fig. 3 of the present drawings the feeding direction of the machine may be reversed, that is, feeding may be from left to right without crumpling the cover strip. When the roll 30 is permitted to engage the platform cover strip the two rolls which rotate about axes obliquely oriented or inclined at an angle with respect to the direction of feed automatically direct the strip into line with the sewing point. Thus, the machine of prior application, Serial No. 446,619 is particularly suitable for sewing the parts of a slip-lasted shoe with a single seam reinforced in areas of special stress.

Since the shoe of the invention may be sewn on ma, chines other than that above described, it is not intended that the above description be construed as a limitation of the invention. It will also be appreciated that from the foregoing disclosure persons of ordinary skill in the art may derive some of the bfinefits of myinvention in slip-lasted shoes embodying minor; variations. For ex-. ample, in a shoe of the two-seam construction reinforce..- ment in stress areas of the size-determining seam may be accomplished in accordance with my invention, and will result ina substantially stronger shoe which will retain its shape through a longer life during wear. Accordingly, it is not intended to limit the invention to the particular arrangement illustrated and described, but rather to rely upon the definitions of the appended claim.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

A slip-lasted shoe having sole and upper blanks and a cover strip wrapped about the edge of the sole blank with the ends in overlapping relationandunited to the sole and upper blanks by a single continuous seam ex-v tending about the entire contour of the sole blank crossing the edges at the ends of the cover strip, the overlap? ping end edges being reinforced by three coincident portions of the same seam.

References Cited in the file of this patent UNITED STATES PATENTS 315,916 Cram Apr. 14, 1885 2,341,675 Walsh Feb. 15, 1944 2,348,952 Braun May 16, 1944 2,359,896 Chandler Oct. 10, 1944 2,386,809 Maling Oct. 16, 1945 2,411,682 Gallo Nov. 26, 1946 2,526,925 Atlas Oct. 24, 1950

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