US3081719A - Machines for sewing imitation moccasin seams - Google Patents

Description

March 19, 1963 H. B. FAKE 3,081,719

MACHINES FOR SEWING IMITATION MOCCASIN SEAMS Filed May 7, 1962 3 Sheets-Sheet 1 Harry B. Fake 15y fi/sfltomey H. B. FAKE March 19, 1963 MACHINES FOR SEWING IMITATION MOCCASIN SEAMS Filed May 7, 1962 5 Sheets-Sheet 2 March 19, 1963 H. B. FAKE 3,081,719

7 MACHINES FOR SEWING IMITATION MOCCASIN SEAMS Filed May 7, 1962 3 Sheets-Sheet 3 3,981,719 MACHINES 1 R SEWBN ll ilTATifiN MOtZCASlN SE M" Harry B. Fake, douth Weynsouth, Mass, assignor to United Shoe Machinery Corporation, Remington, Ni,

a corporation of New .lersey Filed May 7, H62, Ser. No. 192,744 7 Claims. (til. 11237) The present invention relates to moccasin type shoe sewing machines and more particularly to improvements in a machine of the type disclosed in United States Letters Patent No. 2,304,964, granted December 15, 1942, on an application filed in the name of Francis R. Speight, for sewing a seam in a shoe upper in such a way that the threads are exposed on the finished surface of the upper but do not extend through the flesh side, so as to produce roughness inside the shoe or to require the use of a lining within the shoe. I

With the machine of the prior patent a moccasin type two-thread lock stitch seam is inserted through the beveled edges of a top piece and a vamp of a shoe upper, both threads being visible on the finished or grain surfaces of the parts and the amount of exposure inside the upper being at a minimum while forming a tight joint between the parts. To do this, the parts are clamped rigidly throughout an extensive area about the sewing point and are forced firmly into an apex defined by angularly dis posed surfaces within a work support extending in the direction of feed. To clamp the parts, a presser having a tip formed by external work engaging surfaces disposed at the same angle as those in the work support acts primarily on portions of the parts at some distance from the apex of the work support to crowd the beveled edges of the parts together at the apex. In this way the thickness of the beveled edges of the parts at the apex is expanded, the beveled edges being compressed by forces directed parallel to the planes of the parts, so that the tension in the threads passing through the beveled edges will not be resisted by the grip of the work support and presser. By reason of the parallel compressing action full advantage also is obtained from the tension in the thread in producing a tight joint.

The presser of the prior machine has intersecting its angularly disposed work engaging surfaces two transverse notches spaced apart the distance between successive stitches, so that a curved hook sewing needle and a curved awl may pass readily through the beveled surfaces on the parts without necessarily penetrating the inner surfaces thereof, the notches providing space for the material displaced by the needle and awl. of transverse notches there is little likelihood also that the stitches will be pulled through the material or will cause other damage to the work.

When it is desired to insert an imitation moccasin type seam in a one-piece shoe upper rather than in a two piece upper, it has been found that the machine of the Speight patent, which causes parallel compression of the work is detrimental to uniform insertion of stitches, especially where the threads do not pass through the inner surface of the upper. Furthermore, it has been found that if an attempt is made to insert such seam without penetrating the inner surface of the upper there is a greater tendency for the stitches to pull through the material, thus rendering the upper unfit for its intended use.

An important object of the present invention, therefore, is to provide an imitation moccasin type shoe sewing machine, which is capable of operating with extreme uniformity and reliability on a one-piece shoe upper without the drawbacks noted above, particularly where the threads in the stitches do not penetrate through or Through the use i Sfidlfilh Patented Mar. 19, 1953 ice are not exposed within the upper. Other objects are to provide a curved awl which is particularly well adapted for machine sewing of a one-piece shoe upper with an imitation moccasin type scam, the stitches of which do not penetrate both sides of the upper nor are otherwise exposed within the inner surface of the upper.

To these ends the features of the invention reside in the use of a curved hook needle sewing machine having a work support provided with work engaging surfaces disposed with relation to each other and extending in the direction of work feed to form an angle substantially greater than in any similar prior machine, the angle within the work support subtending at least while an internal presser acting to hold the work in place has a tip with work engaging surfaces disposed at a substantially smaller angle than that in the work support, thus causing thicknesswise pressure to be concentrated on the upper at the apex of the angle in the work support rather than along areas of the upper at a distance from the apex in the work support. In this way the penetration of the needle and awl alone causes thicknesswise expansion of the work at the apex of the angle in the work support while leaving the upper within the line of the seam free to recede from the apex as a result of compression at the apex.

To assist in accuracy of stitch formation, and uniformity and alignment in the threads in the stitches exposed outside the grain surface of the upper, a feature of the invention resides in the use of an awl having substantially greater width than thickness radially of its curvature and a cutting blade consisting of two oppositely exposed edges extending at an angle to each other and merging with parallel ridges on the awl facing in the line of the seam. Preferably, the exposed edges on the cutting blade are formed in part by two angularly disposed relatively flat triangular faces outside the curvature of the awl, which faces are joined together along a line running from a point at the extreme tip of the awl and between two separate curved surfaces extending along the shank of the awl outside its curvature, said separate curved surfaces being joined to the angularly disposed faces at an appreciable distance from the awl point.

These and other features of the invention as hereinafter described and claimed will be apparent to those skilled in the art from the following detailed specification, taken in connection with the accompanying drawings, in .which:

FIG. 1 is a perspective detail view, partly broken away and in section, looking from the right front of portions in a moccasin type two-thread lock stitch shoe upper sewmg machine embodying the features of the present invention;

FIG. 2 is a View in right side elevation, partly in section on an enlarged scale as seen from the line IIII in FIG. 7 of a work support and a presser for clamping a shoe upper in the machine of FIG. 1;

FIG. 3 is a partial view in right side elevation of a curved awl employed in the machine;

FIG. 4 is an outer view of the end of the awl looking in the direction of the arrow IV in FIG. 3;

FIG. 5 is an inner View of the awl looking in the direction of the arrow V of PEG. 3;

FIG. 6 is an end view of the awl looking at its point;

FIG. 7 is a sectional plan view taken along the line VII-VII of the parts shown in FIG. 2;

FIG. 8 is a perspective view showing the outer side of an ornamental seam inserted by the machine; and

FIG. 9 is a similar view showing the inside surface of a shoe upper after being sewn by the machine.

Heretofore, where an imitation moccasin type seam is to be inserted without causing the threads to be exposed inside a shoe upper, hand sewing methods have been resorted to, no reliable machine having been developed for this form of seam, up until the present.

The illustrated machine is similar in many respects to that of the Speight patent above referred to and has a curved hook needle 2, a curved work feeding awl 4, a horn 6 having a presser 8 secured thereto, a work support 10, and a rotary hook 212 for carrying loops of needle thread 1'4 about a locking thread 16. To stiffen the needle it is provided with a needle guide 17 cooperating with a guard 18 acting to prevent entanglement of the thread with the needle guide. The awl is actuated from beneath the work to form a perforation for the needle acting from above the work to follow the awl as it leaves the work. When the awl withdraws from the Work it is back fed the length of a stitch and again penetrates the work. Thereafter, the awl and work move in the direction of feed together to a position with the awl perforation in line with the needle ready for its next work penetrating stroke as in the machine of United States Patent No. 1,169,909, granted February 1, 1916, in the name of Fred Ashworth.

In the machine of the Speight patent the work support has work engaging surfaces disposed with relation to each other and extending in the direction of work feed to form an angle of 60 with each other and an internal presser cooperating with the work support has external work engaging surfaces similarly disposed and extending in the direction of work feed. The Speight machine is intended to operate upon the parts of a two-piece moccasin type upper prepared by beveling a top piece and vamp along their complementary edges, so that they may be sewn together with stitches penetrating the bevel faces of the parts as close as possible to shoulders formed at the inner edges of the parts. In performing such an operation it is essential to have the parts throughout substantial areas surrounding the sewing point compressed firmly against each other, especiatlly when operating upon soft, thick work, thus preventing the stitches from being pulled through the material during insertion of a seam or separation of the joint between the beveled edges after insertion of the seam. For this reason the work support and presser of the prior patent are formed to compress and clamp the material of the parts firmly throughout a large area about the apexes formed by their work engaging surfaces and especially along the margins of those surfaces, thus tending to squeeze the beveled edges firmly together at the apexes and into the paths of operation of the needle and awl. In this way the tendency for the parts to separate or be displaced one from another is strongly resisted. To provide space for expansion of the material in a thicknesswise direction the work support of the patent is composed of two separate blocks secured together with a number of replaceable spacing plates between them, the edges of the plates facing the needle and awl being set back at the apex of the angle from the angularly disposed faces of the block, so that the work pieces under compression may expand into the crevice-like space thus provided.

Unlike the machine of the prior Speight patent, the present machine being intended only for operation on single piece uppers, has no problem of separation or displacement of parts operated upon, so that it is desirable to press the work most intensely in a thicknesswise direction along a line connecting the apexes of the angles formed by the Work engaging surfaces of the presser 8 and the work support 10. The remainder of the work outside a narrow bend along these apexes is given limited freedom to flex and expand thicknesswise as much as required in the presentation of the work to the machine, thus facilitating formation of a smooth uniform seam with evenly spaced stitches. To these ends the work engaging surfaces of the present work support form between them an angle of at least 90, while those of the internal presser are disposed at an angle substantially less than that between the surfaces of the work support.

As illustrated, the work support it? has its work engaging surfaces displaced by an angle of 100. The difference between the angles of the work support and presser tends to concentrate pressure on the upper at the apexes of the angles between their surfaces, the work engaging surfaces of the presser 8 being separated by an angle of only leaving a difference from the angle of the work support of at least 20. Also, to retain a reliable and predetermined configuration in the upper, indicated at 19, in FIG. 2, no set back spaces or spacing plates are utilized between the blocks forming the work support. Accordingly, there is no opportunity immediately along the apex of the angle between the work engaging surfaces of the work support for the work to expand or to be compressed heavily during clamping, the outer surface of the clamped upper forming the bend engaging firmly the configuration of the work support throughout the apex of the internal angle. However, such confinement of the work does not prevent ex ansion along the surfaces of the work support and presser in other directions not inconsistent with uniformity and proper location of stitch formation.

As in the machine of the Speight patent the present work support has lower and upper openings 20 and 22 through which the needle and awl pass While penetrating the work. Because the angle between the work engaging surfaces of the work support is greater in the present machine than in the prior one, the areas of intersection between these openings and the work engaging surfaces of the work support are greater than the corresponding needle and awl openings in the work support of the prior machine. Accordingly, there is relatively greater space provided for expansion of the work through these openings than in the prior machine, so that in spite of greater pressure exerted by the presser at its tip on the work the material of the upper has a greater opportunity to bulge, as shown in FIG. 2, into the needle and awl openings, the other portions of the upper between the presser and the work support being left relatively free to adjust themselves without any tendency to form wrinkles or pleats in their surfaces.

Because the needle and awl do tend to displace material during their penetrating strokes the pressure in the present machine retains the transverse needle and awl receiving notches 24- and 26, as in the machine of the prior patent. The awl is so located with respect to the work support and presser that the flat cut formed by it extends through the work piece clear of the outer surfaces. Thus, the material of the upper displaced by the needle and awl during their passage through the work may enter these notches without causing the inner surface or" the upper to be penetrated or the thread of the stitches to be exposed inside the upper.

Another feature of the present invention which contributes materially in producing a uniform seam with smoothly alined threads exposed on the outer surfaces of the upper resides in the use of a curved awl having substantially greater width than thickness radially of its curvature and a cutting blade extending entirely across its width to split from the main body of the upper 19 during penetration a shallow bridge 28 running parallel to the length of the apex of the bend, under which the point of interengagernent between the needle and locking threads in the seam are completely covered, thus providing substantial tolerance for variations in the location and setting of the stitches. Furthermore, the cutting edge on the awl insures sharp corners into which the threads in the stitches are drawn as they are tightened.

Preferably, the cutting blade is sharpened with two oppositely disposed edges 39 and 32 (FIGS. 3 to 6, inclusive) extending at an angle to each other and merging with parallel ridges 34 and 36 facing the line of the seam along opposite sides of the awl. The parallel ridges tend to open up cuts formed by the cutting edges, so that the threads may properly be located within them. The angularly disposed cutting edges 30 and 32 of the awl are formed in part by two angularly disposed relatively flat faces 38 and 49, best shown in FIG. 4. The angularly disposed faces are joined together in an extreme penetrating point 42 at the tip of the awl, joining arched surfaces 44 and 46 along the shank of the awl outside its curvature.

In order to prevent overstressing the bridge 28 formed by the awl during each penetrating stroke so that the bridge may not be partially torn or otherwise displaced, there is formed inside the curvature of the awl beginning at its point a second set of angularly disposed faces 48 and 50 smaller than the faces 38 and 48 (see FIGS. 4 and 5). The smaller faces 48 and 50 extend from the point and merge with a rounded inside face 52. To prevent the awl from cutting too deeply into the material of the upper along the compressed bend between the apexes of the work support and presser and thus drive the material of the upper into the awl receiving notch 26 the point of the awl, the cutting edges and ridges are spaced twice as far, radially of the awl curvature, from the outer surface of the awl as from the inner rounded face 52, as shown in FIG. 3. T o avoid further displacing the upper into the notch 24 during the penetrating stroke of the awl, the faces 33 and 41} are joined together in a relatively sharp elongated plow line 54 (FIG. 4), which prevents deflection of the awl from its proper curvature while entering and passing through the material of the upper. Thus, the plow line 54 and the faces 38 and 40 reduce the tendency for the awl to increase its radius of curvature as the result of reaction to work penetration.

To assist still further in formation of an acceptable seam simulating closely that of a true moccasin scam, the width of the awl 4 between its parallel ridges 34 and 36 is made several times the diameter of the needle 2 and the sizes of the needle and locking threads 14 and 16 are of a gage commensurate with that of the needle. When the point of interengagement between the needle and locking threads is drawn beneath the bridge 28 into a centralized position and tightened the thicknesses of the threads at the points of interengagement produce distinct raised areas 56 with wrinkled depressions 58 between them as in a characteristic hand sewn moccasin seam. In so doing each thread is brought into parallel relationship with itself inside each slit. Thus, the appearance of the seam is greatly enhanced by a row of enlargements, one beneath the central exposed area of each bridge and a desired ornamental result is readily obtained, the tension on the thread and other characteristics of the machine adjustments enabling the distinctive characteristics of the ap pearance to be increased in a desirable manner.

The inner surface of the upper shows no portion of the seam inserted but slight depressions 6% may appear as in FIG. 9 opposite the side of the material from the raised areas.

To enable the work to be guided conveniently in the machine, an adjustable mirror 62 is secured to the machine frame behind the sewing point at the side of the work support first engaged by the upper. If the upper is marked with the shape of the seam to be inserted the reflection of the work renders it more convenient to follow it accu rately.

The nature and scope of the invention having been indicated and an embodiment of the invention having been particularly described, what is claimed is 1. A machine for inserting :a two-thread. lock stitch moccasin type scam, the threads of which enter and emerge from the same side of a single piece of material without penetrating through the other side, said machine having a work support provided with work engaging surfaces disposed with relation to each other and extending in the direction of work feed to form an angle of at least and stitch forming devices including a curved hook needle movable across the angle of said surfaces, in combination with an internal presser having a tip with work engaging surfaces disposed at an angle substantially less than that between the work engaging surfaces of the work support to concentrate thicknesseswise pressure on the work piece along a line connecting the apexes of the angles between the work engaging surfaces of the work support and the presser.

2. A two-thread lock stitch machine for sewing a moccasin type seam, as in claim 1, in which there is provided a curved work feeding awl having substantially greater width than thickness radially of its curvature and a cutting blade extending entirely across its width to split, from the main body of the work piece during penetration, a shallow bridge by which the point of interenga-gement between the threads in the seam is covered.

3. A two-thread lock stitch machine for sewing a moccasin type seam, as in claim 2, in which the cutting blade of the awl consists of two oppositely disposed edges extending at an angle to each other and merging with parallel ridges facing in the line of the seam along opposite sides of the awl.

4. A two-thread lock stitch machine for sewing a moccasin type seam, as in claim 3, in which the angularly disposed cutting edges of the awl are formed in part by two triangular faces joined together in a point at the extreme tip of the awl and joining an arched surface along the shank of the awl outside its curvature.

5. A curved work penetrating awl for use in a twothread lock stitch moccasin seam sewing machine, having substantially greater width than thickness radially of the awl curvature and a cutting blade consisting of two oppositely disposed edges extending at an angle to each other and merging with parallel ridges of the awl facing in the line of the seam.

6. A curved work penetrating awl for a two-thread lock stitch moccasin type seam sewing machine, as in claim 5, in which two angularly disposed triangular flat faces outside the curvature of the awl are joined together along a line running from a point at the extreme tip of the a-wl and between two separate curved surfaces extending along the shank of the awl outside of its curvature and said outside surfaces being joined to the angularly disposed faces.

7. A curved work penetrating awl for a two-thread lock stitch moccasin type sewing machine, as in claim 5, in which the awl has an inner rounded face, and the cutting edges of the awl and the ridges are spaced twice as far radially of the awl curvature from the outer surfaces of the awl as from the inner rounded face.

References Cited in the file of this patent UNITED STATES PATENTS 1,521,853 Augustine Jan. 6, 1925 2,304,964 Speight Dec. 15, 1942 2,399,159 Ashworth Apr. 30, 1946 2,408,738 Crawford Oct. 8, 1946

Claims (1)

1. A MACHINE FOR INSERTING A TWO-THREAD LOCK STITCH MOCCASIN TYPE SEAM, THE THREADS OF WHICH ENTER AND EMERGE FROM THE SAME SIDE OF A SINGLE PIECE OF MATERIAL WITHOUT PENETRATING THROUGH THE OTHER SIDE, SAID MACHINE HAVING A WORK SUPPORT PROVIDED WITH WORK ENGAGING SURFACES DISPOSED WITH RELATION TO EACH OTHER AND EXTENDING IN THE DIRECTION OF WORK FEED TO FORM AN ANGLE OF AT LEAST 90* AND STITCH FORMING DEVICES INCLUDING A CURVED HOOK NEEDLE MOVABLE ACROSS THE ANGLE OF SAID SURFACES, IN COMBINATION WITH AN INTERNAL PRESSER HAVING A TIP WITH WORK ENGAGING SURFACES DISPOSED AT AN ANGLE SUBSTANTIALLY LESS THAN THAT BETWEEN THE WORK ENGAGING SURFACES OF THE WORK SUPPORT TO CONCENTRATE THICKNESSESWISE PRESSURE ON THE WORK PIECE ALONG A LINE CONNECTING THE APEXES OF THE ANGLES BETWEEN THE WORK ENGAGING SURFACES OF THE WORK SUPPORT AND THE PRESSER.

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