US2905122A - Methods of sewing slip-lasted shoes - Google Patents

Description

Sept. 22, 1959 E. QUINN METHODS OF SEWING SLIP-LASTED SHOES Original Filed July 29, 1954 2 Sheets-Sheet 1 Inventor Edward Qumn Sept. 22, 1959 E. QUINN 2,905,122

' METHODS OF SEWING SLIP-LASTED SHOES I Original Filed July 29, 1954 2 Sheets-Sheet 2 United States atent METHODS OF SEWING SLIP-LASTED SHOES Edward Quinn, Saugus, Mass, assignor to United Shoe .Machinery Corporation, 'Flemington, N.J., and Boston,

Mass, a corporation of New Jersey Original application July 29, 1954, Serial No. 446,619, now Patent No. 2,807,224, dated September 24, 1957.

1522112122 and this application June 27, 1956, Serial No.

5 Claims. (Cl. 112-262) This invention relates to improvements in methods for operating on the margins of relatively thin, flexible sheet material of variable widths, such as is employed in a platform cover or wrapper strip, and other parts for a shoe of the slip-lasted or California type.

The methods of the present invention may be per formed on a shoe sewing machine generally similar to that disclosed in United States Letters Patent No. 2,722,- 182, granted November 1, 1955, in the names of N. S. Ferland and the present inventor jointly, and No. 2,742,- 005, granted April 17, 1956 in the name of the present inventor. My methods are more conveniently performed on a machine disclosed in a parent application Serial No. 446,619, filed July 29, 1954, Patent No. 2,807,224, granted September 24, 1957, in the name of the present inventor and of which the present application is a division. In the machine of the prior patents, above identified, a relatively thin, unchanneled blank of flexible woven material, shaped to correspond with the sole of a shoe, isfbrought into edge register with a flat upper blank cut to an accurate pattern designed to form a shoe. The sole and upper blanks are flexed and caused to slide on each other as they are being pressed together to bring their edges into register by hand manipulation while being presented to the machine and, prior to the machine of thepatents, it was necessary in making a platform shoe first to sew the sole and upper blanks and thereafter to attach a variable width platform cover strip of similar relatively thin, flexible material with a second seam along their edges. The second seam preferably was not coincident with the first one, but was spaced inwardly from the edges further than the first one. The second seam, accordingly, took a wider margin of material beyond the seam than'the first one and added little to the strength of the. completed shoe. To avoid the necessity of insertinga second seam in the machine of the prior patents, the three parts, including the sole and upper blanks and the platform cover strip, are attached by'a single seam with their edges in accurate narrow-margin register. For this reason a gage is employed in the latter machine against which all the edges of the parts are pressed firmly, the'coverstrip being guided automatically so that full attention may be given by an operator to proper manual presentation of the sole and upperlblanks to the machine. For leading a cover istrip automatically into a seam connecting the sole and upper blanks of a platform shoe, the machine of Patent No. 2,722,182 is provided with a pilot having a strip engaging roll rotatably mounted on aha-axis inclined with respect to the direction of feeding movement imparted to the Work, a directional force being applied to the strip as it is pulled toward. thesewing point and'forming an acute angle with respect .to the direction of feed. Because of the angle, there is a slight widthwise slippage of the strip along the pilot roll during feeding movementycausing some frictional resistance and imparting appreciable stretching force to the strip. Duringbrdinary sewing operations the frictional resistance aridstretching force are not objectionable. However, under some circumstances it is desirable to insert reinice forcing stitches over the edges of the parts crossed or throughout an area subject to special stress during wear. If reinforcing stitches are inserted by conventional methods considerable time is lost in handling the shoe and in trimming threads. If an attempt is made to insert reinforcing stitches by reversal of the direction of feed in a machine employing a pilot roll similar to that disclosed in Patent No. 2,722,182, the cover strip becomes crumpled, and the progress of the reverse stitching is blocked, the stiffness of the strip frequently being insuificient to project it in a reverse direction past the pilot roll.

The objects of the present invention are to provide a single seam method of sewing slip-lasted shoes with effective reinforcement for the edges of shoe parts, across which the seam connecting them passes and in other areas subject to special stress, to enable the direction of work j reinforcing stitches inserted by the machine.

feed in a platform cover strip sewing machine to be reversed conveniently without crumpling the strip or blocking the reverse feeding movement when reinforcing stitches are inserted, and in other respects to improve the construction of a reinforced platform shoe so sewn.

To the ends indicated, one feature of the present invention consists in sewing a slip-lasted shoe with a seam locally reinforced along those portions which cross the edges of the parts operated upon or in other areas of special stress with reversely inserted stitches formed by uniformly tensioned threads continuing without breaks between the main and reinforcing portions of the seam. The shoe which is produced by this method of sewing is characterized by greatly improved durability and resist ance to excessive strain and does not require trimming of thread ends along the reinforced areas. The methods of my invention may be practiced to advantage on, although they are not necessarily limited to use with the machine disclosed in Patent No. 2,807,224. In that machine a feeding mechanism is provided with a manually controlled lever for selectively reversing the direction of work feed, and the lever is so connected to the cover strip pilot that the strip is released simultaneously from gripping engagement with the pilot roll whenever the feed is reversed. In this way the frictional resistance on the strip offered by the pilot is avoided, and thestrip is enabled to pass freely therethrough during insertion of the reverse stitching. No corresponding difficulty is met in bringing the edges of the. shoe parts into register, the section of the parts operated upon being already stitched in proper edge register.

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

Fig. 1 is a view in front elevation, partly broken away and in section of a post type shoe sewing machine particularly adapted to facilitate the practice of the present invention;

Fig. 2 is a detail view in right side elevation of a feed direction control lever in the machine of Fig. 1;

Fig. 3 is a view in left side elevation on a reduced scale of the machine shown in Fig. 1;

Fig. 4 is a sectional view on an enlarged scale taken along the line IV1V of Fig. 3, showing the parts sur surrounding the sewing point in the machine showingthe operation of the feeding devices and pilot during reversal of the direction of work feed; and

Fig. :7 is a plan view of portions of a shoe showing The apparatus illustrated in the drawings is a lot:

stitch sewing machine of the double clamp and feed type with a straight eye-pointed needle, and a post-type Work support adapted for operation upon marginal portions of a slip-lasted shoe composed of flexible material out to carefully designed patterns in flat blank form to provide a configuration of a shoe shape without the use of a last, when the edges of the blank shoe parts are brought into registering relationship. During operation of the machine the parts are flexed by the operator pro-.

gressively just in advance of the sewing point to bring their edges into register, and the areas along their margins are clamped about the point of needle operation.

Referring to Fig. 7 of the drawings, the parts of a shoe intended to be operated upon by the machine 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, and the forepart piece at 3.

In sewing a slip-lasted shoe constructed with a single seam connecting the upper, sock lining, and cover strip, i is common practice to attach one cover strip piece, as for instance the forepart piece 3, 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 sewing the shoe, it is applied to a last, and a 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. After the cover pieces have been wrapped about the edge of the platform sole, the greatest strain usually comes on those stitches of the connecting seam at the joints between the two cover pieces. Other areas of the seam in different styles of shoe may also be subjected to substantial strain during wear. It is, accordingly, desirable to reinforce the seam connecting the over lapping end edges of the cover pieces or elsewhere in a shoe construction by inserting overlapping coincident stitches. In Fig. 7 the main stitches of a connecting seam are illustrated at 10, and the local reinforcing stitches at 12, which stitches coincide with those previously inserted and extend in opposite directions across the end edges of the cover pieces 6 and 8.

To enable the overlapping reinforcing stitches 12 to be inserted most conveniently with the best results, the machine employed in the method comprising the present invention is equipped with a feed mechanism having a manually operated control lever 14- (see Figs. 1 and 2) carrying a handle 16 arranged to be operated selectively to cause the shoe parts to be fed in a forward or reverse direction in a manner similar to the corresponding parts in the machine disclosed in United States Letters Patent No. 2,671,421, granted March 9, 1954, on application of W. Heimann. 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 at once after inserting the reinforcing stitches without loss of time, and the edges of the shoe parts are united by a single seam with three coincident continuous thread portions crossing the edges of the parts sewed between the main and reinforcing stitches.

For guiding the cover strip pieces 6 and 8, they are directed automatically for unidirectional movement into the sewing point of the machine by being engaged ina strip pilot included in a guide corresponding in construction and mode of operation to that disclosed in Patent No. 2,722,182. The pilot of the machine in that patent has a roll corresponding to that indicated at 18, rotatably mounted on a fixed axis 20 (see Fig. 6) inclined at an angle with respect to the direction of work feed to grip,

and to press the edges of the cover strip pieceswidthwise 4. gage 22 (see Fig. 4) mounted on the frame of the machine directly opposite the sewing point.

To cause the pilot roll 18 to be effective in gripping the wrapper strip for unidirectional movement, the strip is pressed against the periphery for approximately of arc and is drawn toward the sewing point by the feeding action of the machine. To press the strip against the pilot roll, a second roll 24 is rotatably supported on a spring pressed carrier 26 mounted for pivotal movement toward and from the pilot roll on a pin 28 secured to a bracket 30. The bracket 30 also forms a mounting for the axis 20 of the pilot roll and is adjustably clamped: to an angle plate, 321 (Fig. 3) fixed? to. the forward side of a work support post 34. forming a part ofthe machine frame. As the stitch-forming and work-feeding devices of the machine operate, the shoe upper and sock lining parts are manipulated and flexed by the operator to provide a general configuration of a shoe to bring their edges into register and the cover strip 6, 8 is led automatically against the edge gage 22 without attention on the part of the operator aside from initially presenting the edges of the pieces to the sewing point in the machine.

The arrangement of the strip pilot and edge gage are such that they will cause crumpling of the platform cover strip as an attempt is made to reverse the direction in which the strip moves.

The stitch-forming and feeding devices of the machine are the same as disclosed in the prior patents referred to. Briefly, these devices include the straight eye-pointed needle, indicated at 36, a loop taker in the form of a thread case carrying shuttle 38 mounted for rotation on a vertical shaft 40 carried by the work support post 34 (see Fig. l). The needle 36 is secured to the lower end of a reciprocating needle bar 42 slidingly mounted in a carrier 44 movable in the direction of feed toward and away from the operator seated in the front of the machine. Co-operating with the needle in feeding the work is a feeding presser foot 46 having a vertical opening 48 (see Fig. 4) through which the needle passes. The feeding foot is secured to a bar 50 also slidingly mounted for vertical movement in the carrier 44. The feeding foot is mounted to engage the shoe parts in small areas surrounding the needle. The feeding foot also is actuated to clamp the parts against a work-supporting feed dog 52, moving the clamped areas of the work with the feed dog and needle in the direction of feed while the needle is confined within a bore of the feed dog.

To enable unobstructed reversal of the direction of work feed in time to avoid crumpling of the platform cover strip during reversal, the machine includes means connected with a cover strip pilot for simultaneously discontinuing automatic direction of the cover strip during the shift to reverse feeding. To discontinue automatic direction of the strip, it is released from gripping engagement with the pilot roll when the feed control lever 14 is operated. Operation of the feed control lever is efiected selectively by the operator from a forward feed position shown in full lines in Fig. 2 to the broken line position of that figure. For convenience in resuming stitching in the original normal forward direction after reversal, while guiding the shoe parts so that sewing in the original direction may be continued from the point of termination before the first reversal in direction, the control lever is engaged by one end of a spring 54 stretched between it and a fixed portion of the machine frame. When the control lever is released by the operator it quickly returns to its normal forward feed position re-engaging the strip in the guide.

The means for connecting the manually operated feed control lever 14 to the cover strip pilot comprises a cam formed by a surface 55 (Fig. 2) on the upper end of an arm 56 provided at its lower end with a split socket surrounding the shank of the handle 16 on the feed control lever. Passing across the split in the socket is a clamp screw 58. When, the feed control lever is raised to reverse the direction of machine feed the cam at the upper end of the arm 56 engages a follower 60 formed on an arm integrally connected with a rockshaft 62 supported in bearings 64 and 66 rigid with the machine frame. Also secured to the rockshaft 62 is a downwardly extending finger 68 entering the hook of a hook-shaped fixture 70 secured to a bar 72 mounted on the pressing roll carrier 26. As the cam on the arm 56 engages the follower 60, the shaft 62 is rocked, swinging the finger 68 against the fixture 70 and actuating the carrier 26 to release the strip from gripping engagement with the pilot roll 18 and the pressing roll 24. The positions of the parts when thus actuated are shown most clearly in Fig. 6. In these positions the cover strip is free to slide between the rolls 18 and 24 in any direction, so that during reverse feed of the machine no restriction or limitation to movement occurs. As soon as the feed control lever is returned to its forward feeding position the cover strip is again gripped between the pilot and pressing rolls to resume application of the effective engagement of the cover strip with the edge gage as the sewing progresses.

To insure that the stitches inserted while the direction of feed is reversed will coincide with those inserted while the feed is in a forward direction, the movement of the feed control lever 16 is adjusted to give the same feeding movement to the shoe parts in either direction. To this end the control lever has its movements limited by a pair of slotted plates 74 (see Figs. 1 and 2) adjustably secured to the machine frame above and below the feed reversing lever. The slots in the plates have passing through them clamp screws 76 which, when loosened, permit the desired adjustments to be made. For a better understanding of the construction and mode of operation of the machine reference may be had to the parent application.

Although maximum benefits are derived by applying the methods of my invention to reinforcing single-seam slip-lasted shoes in the area where the platform sole and heel wrappers overlap, many minor variations will be obvious to those of ordinary skill in the art from the foregoing disclosure. It will also be appreciated that my invention need not necessarily be practiced on the specific machine described herein for purposes of illustration. Accordingly, it is not intended to limit the scope of the invention to the specific sequence of steps already described, but rather to rely upon the definitions of the appended claims.

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

1. The method of sewing slip-lasted shoes with a single continuous seam crossing the edges of certain parts, which consists in providing sole and upper blanks and a platform cover strip, flexing the sole and upper blanks in advance of the sewing point manually to bring their edges into register thereby giving the blanks a threedimensional shoe form, directing the cover strip into the sewing point, and reversing the direction of sewing after the seam crosses the edges of the parts to insert overlapping reinforcing stitches crossing the edges with continuous thread between the main and reinforcing stitches.

2. The method of sewing slip-lasted shoes with a single continuous seam crossing the edges of certain parts, which consists in providing sole and upper blanks and a platform cover strip, flexing the sole and upper blanks in advance of the sewing point manually to bring their edges into register thereby giving the blanks a three-dimensional shoe form, directing the cover strip automatically into the sewing point, reversing the direction of work feed after the seam crosses the edges of the parts to insert overlapping reinforcing stitches crossing the edges, discontinuing the automatic direction of the cover strip while the stitching is reversed, and thereafter simultaneously resuming the automatic direction of the strip and the feed in the first-mentioned direction to form three coincident portions of the same seam across the edges of the parts with continuous thread between the main and reinforcing stitches.

3. The method of sewing slip-lasted shoes with a single continuous seam crossing the edges of certain parts, which consists in providing sole and upper blanks and a platform cover strip, flexing the sole and upper blanks in advance of the sewing point manually to bring their edges into register thereby giving the blanks a threedimensional shoe form, directing the cover strip automatically into the sewing point, reversing the direction of work feed after the seam crosses the edges of the parts to insert overlapping reinforcing stitches crossing the edges, and discontinuing the automatic direction of the cover strip while the work feed is reversed.

4. The method of sewing, with a single locally reinforced seam, a slip-lasted shoe including sole and upper blanks and a platform cover strip on a machine including an automatic strip guide adapted upon engagement to direct the strip intothe sewing point and upon disengagement to permit movement of the strip away from the sewing point, which method comprises the steps of presenting the blanks and the strip to the machine to form a seam connecting the blanks and the strip, in which presentation the blanks are positioned in register at the needle and the strip is engaged in the guide, manually flexing the sole and upper blanks in advance of the needle to continue bringing their edges into register as the seam progresses thereby giving the blanks a three-dimensional shoe form, reversing the direction of feed, releasing the strip from the guide as the direction of feed is reversed to avoid crumpling of the strip during the reverse feed, inserting reinforcing stitches during reverse feed in an area subject to special stress during wear, resuming feed in the original direction, inserting stitches in the shoe parts upon resumption of feed in the original direction, and re-engaging the strip in the guide after the resumption of feed in the original direction whereby the area subject to special stress receives three overlapping portions of the same seam formed with continuous thread.

5. The method of sewing, with a single continuous seam crossing the edges of certain parts, a slip-lasted shoe including sole and upper blanks and a platform cover strip on a machine including an automatic strip guide adapted upon engagement to direct the strip into the sewing point and upon disengagement to permit movement of the strip away from the sewing point which method comprises the steps of presenting the blanks and the strip to the machine to form a seam connecting the blanks and the strip in which presentation the blanks are positioned in register at the needle and the strip is engaged in the guide, manually flexing the sole and upper blanks in advance of the needle to continue bringing their edges into register as the seam progresses thereby giving the blanks a three-dimensional shoe form, reversing the direction of feed after crossing the edge of a part, releasing the strip from the guide simultaneously with the reversal of feed direction, inserting a few coincident reinforcing stitches crossing the edge of the part during feed in the reverse direction, resuming feed in the original direction and inserting a third set of coincident stitches across the edge of the part upon resumption of feed in the original direction, and simultaneously with the resumption of feed in the original direction re-engaging the strip in the guide whereby three overlapping and coincident portions of the same seam formed with continuous thread are inserted across the edge of the part.

References Cited in the file of this patent UNITED STATES PATENTS 315,916 Cram Apr. 14, 1885 2,341,675 Walsh Feb. 15, 1944 Gleason Jan. 15, 1946

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