US3020861A - Sewing machines - Google Patents

Description

Feb. 13, 1962 E. QUINN 3,020,861

SEWING MACHINES Original Filed Nov. 13, 1956 11 Sheets-Sheet 1 Invenfor Eciwa r d Qu 27m By 72 wAzfornez Feb. 13, 1962 E. QUINN 3,020,861

SEWING MACHINES Original Filed Nov. 15, 1956 11 Sheets-Sheet 2 In 0011 for Edward Qu znn By'hiJAfzOrney Feb. 13, 1962 E. QUINN 3,020,861

SEWING MACHINES :llllLjM m Int/en for Feb. 13, 1962 QUINN 3,020,861

SEWING MACHINES Original Filed Nov. 13, 1956 11 Sheets-Sheet 4 1/7,? w- /25 *v Inventor Edwcz rcZ Quinn By izzJAizarney E. QUINN SEWING MACHINES Feb. 13, 1962 ll Sheets-Sheet 5 Original Filed Nov. 13, 1956 In venfor Edward Quinn Feb. 13, 1962 E. QUINN SEWING MACHINES ll Sheets-Sheet 6 Original Filed Nov. 13, 1956 In venfor EcZwa rd Quz 7m By hz JAifor-p y Feb. 13, 1962 E. QUINN 3,020,861

SEWING MACHINES Original Filed Nov. 15, 1956 ll Sheets-Sheet 7 Feb. 13, 1962 E. QUINN 3,020,861

SEWING MACHINES Original Filed Nov. 13, 1956 11 Sheets-Sheet 8 Invenfor Feb. 13, 1962- E. QUINN SEWING MACHINES l1 Sheets-Sheet 9 Original Filed Nov. 13, 1956 Invenfor 5y izzLrAf/orwey Edwa rd Quinn Feb. 13, 1962 Original Filed Nov. 13, 1956 11 Sheets-Sheet 1O 5% J J 1/; J5 F 1/5 7 56 1% iii Invent-"0r Edward Quinn Feb. 13, 1962 E. QUINN 3,020,861

SEWING MACHINES Original Filed Nov. 13, 1956 11 Sheets-Sheet 11 Invenfor Edward Quinn By hzLrA zfo rrz/ey United States Patent Ofiice 3,020,861 Patented Feb. 13, 1962 3,020,861 SEWING MACHINES Edward Quinn, Peabody, Mass., assignor to United Shoe Machinery Corporation, Boston, Mass., a corporation of New Jersey Original application Nov. 13, 1956, Ser. No. 621,796, now Patent No. 2,954,748, dated Oct. 4, 1960. Divided and this application Jan. 30, 1959, Ser. No. 790,244

20 Claims. (Cl. 112-34) This invention relates generally to improvements in sewing machines, and more particularly to cooperatively associated thread control and lubricating devices especially advantageous in sewing machines employing eyepointed needles. The present invention has already been disclosed in an application for United States Letters Patent Serial No. 621,796, filed November 13, 1956 in my name, now Patent No. 2,954,748, granted October 4, 1960, and of which application the present one is a division.

When a conventional sewing machine is employed for inserting a seam having abrupt curvature or change in direction, the reliability of operation of the machine is often impaired to such a point that the seam lacks the uniformity required for commercial acceptance. The machine malfunctions to which this invention is directed, are caused by failure of the beak of the looper or shuttle to enter each needle loop with certainty because the needle thread is displaced from its looper engaging position as the work piece is excessively re-oriented about the needle without interrupting the sewing operation. Missed stitches resulting from failure of the looper beak to enter needle loops are encountered with objectionable frequency in sewing together the parts of a slip-lasted shoe, particularly when the wrapper strip of the shoe is directed by a guide such as that of the parent application which causes the strip to impress upon the needle abnormally high compressive forces not present in normal sewing operations. Although the guide of the parent application has a tendency to render conventional sewing instrumentalities less reliable in their operation, its use is still desirable to minimize distortion during sewing and to improve the lasted condition of the wrapper strip about the platform in the completed shoe.

In operating upon slip-lasted shoes a number of other factors render conventional sewing machines unreliable and missed stitches more objectionable than, for example, in sewing cloth presented to the machine in fiat condition. One such factor is the need for relative slippage between the shoe parts at the sewing point to give the parts a shoe form which is retained by the seam. Since the parts of a shoe are generally of materials which resist deformation to a much greater degree than cloth, additional forces are applied to the needle and tend to interfere with accurate presentation of needle loops to the looper beak. In shoe sewing operations it is also common practice to coat the thread with preservative or water-proofing compounds which also alter the looping characteristics of the thread and tend to be deposited upon thread-contacting surfaces of the machine, modifying critical shapes and thereby presenting more problems rarely encountered in sewing cloth work pieces. If the seam connecting the parts of a slip-lasted shoe is of the chainstitch type, it is readily appreciated that a missed stitch further causes the shoe to lose its shape.

It is accordingly an object of the present invention to provide an improved sewing machine in which needle loops are entered with certainty by the beak of the looper. It is a more particular object to assure entry of the looper beak into the needle loop while inserting a chain stitch seam in a work piece being compressed longitudinally about the needle and/ or being turned about the needle without stopping the progress of the seam.

It is another object to provide a sewing machine which in its operation subjects'the thread to a minimum of abrasion. Another object is to provide a machine in which the thread although subjected to a minimum of abrasion does not receive a supply of lubricant at a point where it can be transferred to work contacting portions of the machine. Still another object is to provide a machine in which the leading end of the thread, at the beginning of a seam, may readily be locked in place by the first formed stitch. Still another object is to provide devices for achieving uniformity of operation and minimum abrasion to the thread in sewing machines of different types and to achieve superior operating characteristics at a minimum cost. 7

The foregoing and other objects of the present invention are achieved in an illustrative machine including a work-supporting block of novel design constituting a feature of the invention. The block is formed with a needle reinforcing bore positioned in alinement with the needle of the machine and with a thread control notch which communicates with the bore. In cooperation with outer surfaces of the block the notch causes each needle loop to be presented to the looper in uniformly precise position regardless of forces acting upon the needle and upon the thread. In order to obtain the required accuracyin presenting the needle loops, the slot is necessarily limited in its width and thus is subject to clogging by deposits from the thread. It has been found, however, that the application by anovel lubricating device of a sinall quantity of solvent to the thread assists greatly in maintaining the narrow slot free of accumulations of materials carried by thread. The lubricating device is constructed, according to another feature of my invention, to apply small quantities of lubricant or solvent to the looperof the inachine so that the lubricant or solvent is thereafter transferred during each sewing cycle to a relatively short length of thread being moved through the loop orienting notch, the work and the eye of the needle. The substance picked up by the thread from the looper is accordingly effective not only where necessary for keeping the thread control instrumentalities of the machine free of accumulations but also to minimize abrasive action upon the thread in the work and in the needle eye without any possibility of throwing off from the thread, onto the work supporting surfaces of the machine, quantities of the lubricant which could cause staining of the work.

The foregoing and other features of the invention, including a groove formed in the upper surface of the work supporting block for locating the leading end of the thread at the start of the seam so that it is locked inplace by the first stitch, and a thread storage indentation which cooperates with the loop orienting groove, will be more readily understood from the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a view in left side elevation of portionsof a slip-lasted shoe sewing machine, embodying features of the present invention;

FIG. 2 is a view in front elevation of the parts surrounding the sewing point in the machine illustrated in FIG. 1, certain cover parts having been broken away and shown in section; v i

FIG. 3 is a sectional detail view taken in left sideelevation of a portion of a work clamp, a wrapper strip overfeeding device, and some of the mechanisms for actuating them shown in stopped positio ns'of the machine;

FIG. 4 is a sectional plan view of the clamp and overfeeding actuating mechanisms shown in FIG. 3, taken along the line of IVIV of thatfigure;

FIG. 5 is a detail plan v iew onanenlarged scale showing an eccentric connection on'a sewing shaft in the overfeed mechanism;

FIG. 6 is a detail view in left side elevation of the overfeed actuating mechanism for the wrapper strip, looking from the left side of the machine with the parts shown in positions somewhat advanced from those of FIG. 3;

FIG. 7 is a perspective detail view of a right-angle link in the overfeed mechanism;

FIG. 8 is a detail view in left side elevation and partly in section of a driving eccentric and an actuating finger connected to the overfeed device, shown in positions still further advanced from FIG. 6;

FIG. 9 is a detail view showing work clamping and feeding devices together with the Wrapper strip overfeeding device;

FIG. 10 is a sectional detail view taken along the line XX of FIG. 9;

FIG. 11 is a sectional detail view taken along the line XI-XI of FIG. 9, indicating the position of a wrapper strip as it is being fed to the sewing point in the machine;

FIG. 12 is a perspective detail view of the wrapper strip overfeeding device;

FIG. 13 is a detail view on a reduced scale, taken in front elevation, showing a set of control connections for rendering the wrapper strip overfeeding device inoperative when the machine is brought to rest at the end of a seam;

FIG. 14 is a detail view in left side elevation showing the manner of operation of the overfeeding device;

FIG. 15 is a similar view on an enlarged scale illustrating the manner in which the overfeeding device opcrates;

FIG. 16 is a sectional detail view taken along the line XVI-XVI of FIG. 15;

FIG. 17 is a similar view of the parts shown in FIG. 15, illustrating the manner in which a wrapper strip is compressed lengthwise during the operation of the machine;

FIG. 18 is a sectional detail view in left side elevation of the overfeed actuating mechanism, shown in a position advanced slightly beyond that indicated by the position of the eccentric in FIG. 8, the overfeed device being illustrated at the beginning of its overfeeding movement;

FIG. 19 is a similar detail view of the driving eccentric for the overfeed device, shown in the same position as in FIG. 18;

FIG. 20 is a plan view of the parts shown in FIG. 18;

FIG. 21 is a detail view in front elevation and partly in section of a portion of the overfeed mechanism, as viewed along the line XXI-XXI of FIG. 20;

FIG. 22 is a view of a set of shoe parts in the process of being sewn together;

FIG. 23 is a detail plan view of a set of convexly curved shoe parts along their toe portions, illustrating the action of the overfeed mechanism;

FIG. 24 is a detail plan view of a portion of the overfeed actuating mechanism shown in FIG. 18;

FIG. 25 is a detail view similar to that of FIG. 23 with the overfeed mechanism acting along a concavely curved shank portion of a shoe;

FIG. 26 is a detail view on an enlarged scale and in left side elevation of some of the work clamping and stitchforming devices in the machine, including a lubricator for the loop taker looking from the left of the machine;

FIG. 27 is a detail view in front elevation partly broken away and in section showing the operation of a thread end locating groove for retaining the leading end of thread at a position where it will be gripped by the first completed stitch in a seam;

FIG. 28 is a plan view of a work feeding and a nonwork feeding presser foot in the machine;

FIG. 29 is a plan view of a feeding and a nonfeeding work support which cooperate with the presser feet of FIG. 26 to form feeding and non-feeding work clamps;

FIG. 30 is a sectional detail view in left side elevation of the parts shown in FIG. 27;

FIG. 31 is a sectional detail view in front elevation of the loop taker and the feeding and nonfeeding work clamps, illustrating the manner of operation of the improved thread locating groove shown in FIG. 27

FIG. 32 is a detail plan view of the nonfeeding work support;

FIG. 33 is a sectional view in front elevation of the same parts illustrated in FIG. 31, showing the operation of a thread locating notch after the needle has penetrated the work during formation of the first stitch in a seam;

FIG. 34 is a similar view showing the manner of operation of a thread storage indentation in a needle guide as the needle starts to retract from the work;

FIG. 35 is a similar view of the same parts showing how the loop is forced through the needle eye into a path of the loop taker at a position in a sewing cycle later than that illustrated in FIG. 34;

FIG. 36 is a side detail view of the shoe parts showing the position of the thread end at the beginning of a seam;

FIG. 37 is a view in left side elevation and on a reduced scale of a portion of the machine, illustrating a looper lubricating device;

FIG. 38 is a sectional detail view in front elevation with certain parts removed to expose the looper lubricating device;

FIG. 39 is a detail plan view of the looper lubricating device;

FIG. 40 is a detail view in front elevation of the looper lubricating device; and

FIG. 41 is a sectional plan view of the parts for supporting the looper lubricating device, as viewed from the line XLI-XLI in FIG. 38.

The machine illustrated in the drawings is a straight eye-pointed needle chain-stitch sewing machine of the Wilcox and Gibbs type, similar to that disclosed in a prior application for United States Letters Patent Serial No. 503,904, filed April 26, 1955, now Patent No. 2,905,- 118, granted September 22, 1959, in my name. The machine has a main sewing head frame 2, within which is mounted a vertically reciprocating needle bar 4 at the lower end of which the needle, indicated at 6, is clamped. Cooperating with the needle is a looper or loop taker 8 acting with other stitch-forming devices corresponding to those described in the prior application to form a chain stitch seam. To form the stitches the looper has a loop entering beak 10, which moves in a circular path across the needle. After taking the loop off the needle the loop taker withholds the loop as the needle withdraws from the work and, during the next penetrating stroke of the needle, the withheld loop is enchained with that carried by the needle through the work.

The illustrative machine is intended to operate upon superposed marginal portions of a shoe upper 12, a sock lining 14, and a platform wrapper strip 16 (see FIGS. 15 and 17). During assemblying and stitching operations of a slip-lasted shoe, the parts are flexed and caused to diverge through different angular displacements about the line of the seam inserted by the machine( Flexure of the upper and sock lining is accomplished manually by the operator who directs the parts, one with each hand, in advance of the point of operation of the needle in the machine. In order to direct the platform wrapper strip 16 it is guided automatically through a wrapper strip advancing pilot, including an overfeed member acting with an orbital feeding movement. The strip advancing member comprises a finger or claw 18, best shown in FIGS. 14 and 16. The claw 18 is guided for movement toward and from the point of operation of the stitch-forming devices with a strip advancing movement greater than the length of feed imparted to the shoe parts by the feeding clamp to bulge the strip in such a way that it is compressed lengthwise by the work-clamping devices and stitched in this relation to the upper and sock lining of the shoe being assembled.

As in the machine of the prior application, the work clamping and feeding devices consist of a feed clamp connected to a carrier for actuating it while gripping the work and a nonfeeding work clamp connected directly to the frame 2 of the machine. Referring to FIGS. 1, 26, 2.7 and it may be seen that the nonfeeding work clamp comprises a work support or table 29 clamped for vertical adjustment by a screw 22 to a rearwardly projecting portion of the frame 2 and a presser foot 24 attached by a clamp screw 26 (FIG. 2) to the upper end of a vertically sliding bar 28 (FIG. 1).

The work feeding clamp comprises a work feeding support or table 30 secured for vertical adjustment by a screw 32 to a carrier 34 pivoted for swinging movement on a bolt 36 passing loosely through it into a portion of the frame 2. Cooperating with the feeding work support is a feeding presser foot 38 secured by a screw 40 to a block 42 at the upper end of a vertically sliding bar 44 and arranged to act on the work throughout an area centered about the point of needle operation. The bar 44 slides in bearings in the carrier 34 and is pressed downwardly to grip the work by a compression spring 46 surrounding the bar 44 and acting between a bearing on the carrier and a block 48 secured to the bar 44, the feeding foot '38 being actuated in timed relation to the movements of the nonfeeding presser foot 24, alternately to clamp the work with a yielding pressure, first by the nonfeeding foot and then by the feeding foot. The mechanism for actuating the presser feet alternately to clamp the work and to release it is more fully described in my prior application and includes, briefly, a pair of links 50 and 52, a link 54 connecting a central joint between the links 50 and 52 with a pivot in the lower arm of a lever 56 and a connecting rod 58 extending between the upper arm of the lever 56 and an eccentric 60 (see FIG. 3) on a main sewing shaft 62, the connecting rod 58 having formed at its forward end a strap surrounding one portion of the eccentric 60. The arrangement of the work feeding clamp is such that the presser foot 38 clamps the work along the line of work feed beyond the location of the nonfeeding presser foot 24 to hold the wrapper strip While being compressed by the non-feeding foot.

To impart a work feeding movement to the feeding clamp, comprising the work support 30 and the presser foot 38, mechanism is provided similar to that disclosed in the prior patent application. This mechanism includes a right angle arm 64 (FIG. 4) secured to the upper end of the carrier 34, to which is pivotally connected a link 66, in turn pivotally connected between a feed adjusting link 68 and a connecting rod 70 (see FIG. 6), the lower end of which rod is formed with a strap surrounding the portion of the eccentric 68 not occupied by the connecting rod 58.

The work feeding clamp actuating mechanism causes the presser foot to have imparted to it a.4-motion feeding movement, as illustrated by the broken outlines a, "12, and c, and the solid outline of the work feeding presser foot 38, which represents the fed position thereof in FIG. 17. Thus, the presser foot 38 after the work is fed moves to the position a to release the work, back feeds to the position b, and then clamps the Work at a new location at the position 0. During the back feeding and feeding movements of the feeding foot 38 the feeding work support 30 moves forwardly and rearwardly but no vertical movement is imparted thereto. The work feeding clamp comprises the work support 30 and the presser foot 38 has forked work-engaging ends located in surrounding relation to the work-engaging surface of the nonfeeding clamp (see FIGS. 27 and 28), the forked ends of the feeding support 30 being relatively narrow and moving within grooves of the nonfeeding work support 20. The nonfeeding presser foot 24 has a needle guiding bore which surrounds the point of operation of the needle to grip the work against a portion of the nonfeeding work support 20, which is formed as a block interrupted by a circular needle guiding bore alined with the needle guiding bore of the presser foot 24..

To insure that the wrapper strip will bulge uniformly and always in the same manner sothat it will be compressed lengthwise by the work clamping devices to the same extent throughout the seam inserted, the strip passes along a ramp 72 (FIG. 9) before reaching the nonfeeding work support 20, the ramp having a surface inclined at an angle of 45 and formed by a right-angle flange on a plate 73. The ramp along which the strip passes is disposed at an obtuse angle with respect to the work-engaging surface of the work support, the arrangement being such that the bulge in the strip takes place between the wrapper strip advancing claw 18 and the feeding presser foot 38, the wrapper strip being clamped by the feeding presser foot 38 against the feeding work support 30 at this time. As the nonfeeding presser foot 24 engages the bulge, indicated at 74 (FIG. 15), in the wrapper strip, it is flattened into the position shown in FIG. 17 and compressed in a lengthwise direction during the neXt succeeding work penetrating stroke of the needle, the thread carried through the work assisting in retaining the wrapper strip in flattened condition and preventing release of the lengthwise compression imparted to the wrapper strip during the clamping action of the nonfeeding foot.

Bulging the wrapper strip away from the nonfeeding work support 20, as shown in FIG. 15 causes the upper and sock lining of the shoe also to be raised somewhat in advance of the point of the needle operation, the parts beyond the point of needle operation being secured by the feeding foot 38 as well as by the completed stitches against displacement from each other. As the nonfeeding foot 24 descends from the position of FIG. 15, the clamping action of the foot 24 in flattening the bulge 74 of the wrapper strip transfers the compressing strains along the strip in the direction of work feed toward the sewing point.

The claw 18 in overfeeding the Wrapper strip 16 is given an orbital motion in a triangular path, both feeding and back feeding in accurate timed relationship with movements of the work-feeding foot 38. Referring more particularly to FIGS. 15 and 17, and starting with the solid line position of the claw 18, the work-feeding foot 38 also assumes its solid line work-clamping position of FIG. 17. After the feeding foot 38 disengages from the Work by moving vertically to the broken line position a (FIG. 17), the claw also is back fed horizontally to its broken line position a to disengage the wrapper strip. The claw then is back fed While out of engage ment with the work and eventually to the broken line position b (FIG. 17) while descending into a strip reengaging position. During these disengaging, back feeding, and re-engaging movements of the claw, the wrapper strip is retained in a position against lateral displacement, out of line with the point of needle operation.

For actuating the claw 18 through its feeding and back feeding movements, it is supported by an integral arm 76 from which it projects with an offset to the left (see FIGS. 4 and 12). The arm 76 has a lower flattened portion provided with a vertical slot through which a clamping screw 78 passes into threaded engagement with an angular fixture 80 to which it is secured for vertical adjustment. The fixture 80 is clamped to a horizontal arm of a lever 82 (FIG. 2) by a screw 83 passing through the arm of the lever into a grooved end of the fixture. The lever 82 has an integral downwardly extending rod portion 84 (FIG. 6) formed at its upper end with an offset hub surrounding the upper end of a vertical spindle 86 (FIG. 4) to which it is pinned. The central portion of the spindle is rotatable in a block 88 formed with a flange clamped to a plate 90 (see FIGS. 2 and 4), by a screw 92 passing through the flange of the block 88 and into threaded engagement with the plate 90. The plate 90 in turn has at its upper end a vertical slot through which a screw 94 passes into threaded engagement with the lower end of an angle bar 96 secured at its enlarged upper end by a screw 98 passing through a horizontal slot in a pivot plate 100.

The four interconnected members between the claw 18 and the pivot plate 100 described above all act as a single unit with a swinging motion about a pivot formed by a shoulder screw 102 passing loosely through a horizontal arm of a right-angle link 104 (FIG. 7) and into threaded engagement with the pivot plate 100. In swinging about the shoulder screw 102 the claw 18 moves toward and from the ramp 72, along the surface of which the wrapper strip passes in its course to the sewing point of the machine.

The claw 18 is held yieldingly against the wrapper strip on the 45 surface of the ramp 72 through the action of a tension spring 108 (see FIG. 2) stretched between a pin 110 on the block 88 and a clip 112 secured by a screw 114 to a lever 116, the purpose of which will be described hereinafter. The action of the spring 108 swings the claw 18 downwardly toward the 45 surface on the ramp about the shoulder screw 102 as a center. To prevent vertical displacement of the spindle 86 from the block 88, the lower end of the spindle below the block has secured to it a collar 118 (FIGS. 6 and 12).

To disengage the claw 18 from the wrapper strip on the ramp at the end of the feeding movement of the claw the pivot plate 100 has secured to its central portion a block 120 (see FIGS. 3, 4, and 12). The block 120 has a vertical groove within which is fitted a downwardly extending finger 122 and a screw 124 passing through a slot in the finger and into the block 120 secures the finger thereto. At its lower end the finger is formed with an inclined cam surface arranged to be engaged by a lateral projection 127 from a rectangular plate 126 secured to the connecting rod 68 (see FIGS. and 8). During the rising movement of the connecting rod 68 the projection 127 having an inclined surface engages the inclined surface on the finger 122 and lifts the entire assemblage of parts, including the claw 18, from the wrapper strip at the same time in which the work feeding foot 38 is raised from engagement with the work.

The feeding and back feeding movements of the claw 18 are impressed upon it through shaft driven mechanism including connections with the work feeding devices and the feed carrier 34. These connections include a link 128 pivoted at one end by a screw 130 to the upper end of the feed carrier 34 and at the other end by a screw 132 to the right-angle link 104. The screw 132 passes loosely through the link 128, through a vertical slot 134 in the link 104 and into a clamp nut 136 (FIG. 4) slidingly mounted in a vertical groove in the link 104. To prevent displacement of the screw, it has a shoulder seating with a gripping action against the link 104. Movement of the screw 132 by the link 128 causes the link 104 to swing about a screw 138 passing loosely through the upper end of the link 104 and into engagement with a fixed plate 140 secured to the frame 2 of the machine (FIG. 3). In swinging rearwardly about the screw 138 the link 104 carries with it the shoulder screw 102, moving the assemblage, shown in FIG. 12, of the parts 100, 96, 90, 88, 86, 82, 80 and 76 rearwardly, while the claw 18 is retained yieldingly in engagement with the wrapper strip on the ramp bracket 73, imparting a feeding movement to it. To impart a back feeding movement to the claw 18, the link 104 is swung forwardly about the screw 138 while the claw is raised from engagement with the wrapper strip.

In order to prevent disengagement of the strip from the advancing claw 18, and to enable the claw to move laterally to follow the curvature of the strip, the lower end of the rod 84 (see FIGS. 2 and 6) is confined at opposite sides within a guideway of a block 142 made fast to an adjusting lever 144, shown more clearly in FIGS. 1 to 4, inclusive, 6, 18, 20, 21, and 24. The adjusting lever 144 is operable during sewing, and has a downwardly 8 extending threaded stud 145 at its rearward end (FIG. 6) passing loosely through a horizontal central portion of an angular plate 146. The plate 146 is secured by screws 148 (FIG. 1) to a right-angle bracket 150 secured by a screw 152 to the frame 2 of the machine.

The adjusting lever 144 is held in place on the bracket 146 by a nut 154 (FIG. 6) engaging the threaded stud 145 on the adjusting lever 144. Projecting forwardly from the plate 146 is a fixed arm carrying an arcuate sector 156 formed along its upper edge with a series of notches engaging the under surface of the adjusting lever 144 to retain it releasably in adjusted position. The arrangement of the stud on the adjusting lever, to which the nut 154 is threaded, is such, that at the end of the strip advancing movement of the claw 18, the rod 84 comes into vertical alinement with the stud. Thus, at the end of the strip advancing movement of the claw, the claw always reaches the same lateral position regardless of the position of the lever 144. The lateral position of the claw, however, is changed during its back feeding movement when the angular position of the adjusting lever 144 is shifted, the claw swinging about the vertical spindle 86 as a center during its lateral movement.

During normal operation of the machine when no lateral movement is to be impressed upon the claw 18, the lever 144 is moved and held in a central position on the sector 156 both by frictional engagement with the notches on the sector and by engagement of the sides of the lever by a pair of slotted stops 158 clamped to the front face of the sector 156 by screws 160 passing through the slots in the stops and into threaded holes in the sector 156. The lengths of the stops 158 and the spacing of the screws are such, that when the screws are loosened the stops are movable to positions in contact with the lever 144 where they hold the lever securely between them (FIGS, 2 and 4). To enable sewing about a convexly curved portion of a wrapper strip the left hand stop 158 is shifted on its clamp screw away from the adjusting lever to a position indicated in FIG. 24, leaving the adjusting lever free to be moved toward the left. When moved toward the left the adjusting lever causes the strip advancing claw 18 to be actuated partially from the left to the right during sewing, from the broken line position of FIG. 23 to the solid line position rather than straight forwardly and rearwardly. In this way a convexly curved portion of the strip extending from the left toward the sewing point in the machine is continually engaged by the strip advancing claw as the claw moves with the strip toward the sewing point without permitting escape of the strip. To enable sewing about a concavely curved portion of a wrapper strip (FIG. 25) the claw is caused to be actuated partially from the right to the left in feeding the wrapper strip. This is accomplished by shifting the adjusting lever to the right of it central position, the stop 158 at the right having been adjusted on its screw 1.60 to accommodate the shift of the adjusting lever. If the stops 158 are secured in proper adjusted positions a shift of the lever 144 may be conveniently accomplished while the machine is running just in advance of the approach of the convexly or concavely curved portions of the strip.

As a further means to prevent lateral displacement of the claw 18 from the wrapper strip during disengagement and back feeding movement of the claw 18 while the adjusting lever 144 is maintained in its central position, according to this feature of the invention, the wrapper strip as it moves along the ramp 72 in advance of the claw 18 passes through a frictional device. The frictional device comprises a thin yielding plate 162 shown more clearly in FIGS. 9, 10, 15 and 16. The yielding plate 162 has an upturned free end facing toward the oncoming wrapper strip as it approaches the stitching point. It is also formed with a sharpened lower edge corner 164 extending in the direction of strip movement to impart a widthwise directional force to the strip with a sled runner action. To enhance the widthwise directional action of the sharp corner 164 on the strip, there is formed integrally with the surface of the ramp plate 73, along which the strip passes in advance of the yielding plate 162, a rib 166 arranged to raise the marginal portion of the wrapper strip above the level of the remainder of the ramp. The rib forms a lengthwise reverse fold 168 (see FIG. 16) about the sharpened corner 164 of the plate 162. An upper left hand corner 170 (FIG. 11) of the rib also may be sharpened to improve the strip guiding action. By this construction the directional action on the strip is varied with the stiffness of the strip, so that the greater the stiffness the stronger the directional action is and the less likelihood there is for lateral displacement of the strip.

The yielding plate 162 together with the rib 166 also acts as a frictional device to impart a slight resistance to movement of the strip toward the sewing point in the machine and as the work feeding devices operate the overfeeding claw applies a widthwise force to the strip in a direction to bring it into line with the sewing point in the machine. In so doing the right edge, indicated at 172, of the strip (FIGS. 11 and 16) is pressed uniformly against one side of the supporting arm 76 of the claw 18. The side of the arm 76 is located in alinement with an edge gage 174 adjustably secured to the work-engaging surface of the work support at one side of the point of operation of the needle. The widthwise force of the wrapper strip, thus induced by the overfeeding and lengthwise compressing action of the claw 18 and by the frictional resistance of the yielding plate 162 on the wrapper strip, holds the strip from displacement from both the arm 76 and the edge gage 174, except for abruptly curving portions of the strip.

It has been found that if the sharpened corner 164 of the plate 162 is made exactly parallel to the movement of the wrapper strip along the arm 76 and the edge gage 174 there is a tendency for the arm during the back feeding movement of the claW 18 to raise the edge of the strip and curl it to an undesirable extent, so that the guiding action of the arm on the strip is lost. Accordingly, instead of mounting the plate 162 with its sharpened corner 164 extending exactly parallel to the wrapper strip movement it is inclined by a small angle, indicated at 176 in FIG. 11, diverging from the arm 76 in the direction of feeding movement. For most purposes, a diverging angle 176 of two or three degrees has been found effective to relieve the pressure of the strip edge against the arm 76 sufficiently to prevent curling or displacement of the strip edge against the arm. Not only does the diverging angle 176 prevent curling of the strip edge on the arm 76 but in case of rearward slippage of the strip during back feeding movement of the claw 18, a slight pressure, as a result of the inclination of the edge 164 is imparted to the strip to maintain it firmly in contact with the arm 76. Thus, rearward slippage of the strip, which occurs where the feeding movement of the claw 18 is greater than can be accommodated by lengthwise compression of the strip, will not cause displacement of the strip from the arm. Under these conditions any excessive amount of overfeed does not accumulate but is compensated for by rearward movement of the strip beneath the yielding plate 162.

To mount the yielding plate 162 above the ramp 72 it is formd with a vertically slotted tab through the slot of which passes a screw 178 (FIGS. 9 and engaging threads in a vertical flange of a cover 180 for protecting the directional overfeecling devices. Loosening the screw 1178 enables the position of the plate to be adjusted in accordance with the thickness and stiifness of the wrapper strip operated upon. The cover 180 is constructed with an integral slotted lug engaged by a clamp screw 182 (see FIG. 2) received within a threaded opening in a frame bracket 184 (FIGS. land 2) of the machine.

When it is necessary to shift the adjusting lever 144 during operation of the machine to accommodate the curvature of the wrapper strip the action of the frictional device is relaxed. For this purpose it may be necessary to loosen the screw 178 and raise the plate 162 so that it does not press so strongly on a wrapper strip or the plate may be removed entirely.

The feature of the invention relating to the needle reinforcing block is partially disclosed in my prior application above referred to. The reinforcing block is best shown in FIGS. 31 to 35, inclusive, of the present drawings, and, as in the machine of the prior application, is an integral part of the nonfeeding work support 20. The block is formed with a needle guiding and loop positioning bore 188 alined with the path of the needle and provides a guiding clearance for the needle equal to the thickness of the sewing thread. At the side of the needle with the completed stitches the block has an outlet slot 190 (FIG. 32) entering the bore and having a width narrower than the diameter of the needle.

To deflect the loop of thread carried through the work by the needle and to hold it in a position separated angularly about the needle from the outlet slot where the beak 10 of the looper 8 will enter uniformly and with certainty regardless of any rotation of the work about the axis of the needle or other variable factors, the inner wall of the bore 188 has a notch 192 (see FIG. 31) displaced toward the looper about the axis of the needle in an angular direction from the outlet slot 190 by approximately After the needle reaches the lower end of its work penetrating stroke it begins to retract and to open out the loop carried thereby into the notch. In this way the notch guides the loop toward the looper path and holds it in a position where the looper beak will enter with certainty.

The loop deflecting notch 192 intersects not only the wall of the bore in the reinforcing block but also an outer surface 194 at the under side of the block nearest the looper 8. Accordingly, the notch engages the thread in the loop above the path of the looper beak, while leaving the space below the surface 194 open for rotation of the looper. The beak 10 on the looper passes closely Within a right angularly shaped recess formed by the intersection of the surface 194 and a projection 196 on the block 20 extending downwardly toward the looper from one edge of the needle confining bore 188 (see P16. 34). The downward projection 196 on the block serves to engage the supply side of the loop of thread carried by the needle through the work and to force it into the path of the looper beak 10, through the needle eye as the needle retracts from the work as shown more clearly in FIG. 35.

With the use of certain types of stiff or resilient sewing thread, especially those containing synthetic fibers the pressure on the thread at the supply side of the needle produced by close proximity of the projection 196 produces such a sharp bend or kink in the thread at the eye of the needle that excessive friction of thread in the needle eye results. This kink is formed while the needle is penetrating the work and the heat of the needle from friction with the work causes the kink to remain, as illustrated at 197, and to resist further easy passage of the thread through the needle eye. To assist in forcing the kink 197 in the thread out of the eye of the needle the surface of the projection 196 along which the needle passes is provided with a thread storage indentation 198, in which a limited amount of thread is displaced from contact with the needle, closer to the eye of the needle than the deflecting notch 192 while the needle is rising from its maximum work penetrating position. With the use of the thread storage indentation 198 in the projection 196 the abrupt bend in the thread at the supply side of the needle is avoided, as illustrated in FIG. 34, and the thread is pushed easily through the needle eye (FIG. 35). During the retraction of the needle from the position of FIG. 34 and while a needle loop is being opened up for the beak it of the looper the thread within the storage indentation is gradually forced through theneedle eye from the notch into the path of the looper beak without encountering any substantial frictional resistance during its passage through the needle eye.

In order to insure that the first stitch of a new seam will be formed and tightened in a satisfactory manner it has been found desirable to provide means for locating each leading end 200 (FIGS. 2 and 31) of the thread supported loosely in the machine as new work is introduced. To this end thread locating means is provided in the block, forming the nonfeeding work support 20 to retain the leading end 200 at a position along the seam line in advance of the point of needle operation, where it will be gripped by the first completed stitch in the seam. For this purpose the block portion of the nonfeeding work support 20 has cut into its work-engaging surface a thread locating groove 202 extending at right angles to the line of the seam inserted, when viewed from above. The groove 202 is disposed at a position along the seam line slightly in advance of the point of needle operation (see FIG. 32). If the thread end 200 is held in the groove by the operator and the edge of the work pressed against the thread, then during the first stroke of the needle in a new seam a loop of thread is carried across the end 200 while the work is being fed a stitch length and the next succeeding stroke of the needle will carry a second loop through the work beyond the leading end 200, thus gripping the leading end against the work by the first completed stitch, as illustrated more clearly in FIG. 36. As the sewing progresses the leading thread end 200 is drawn from the groove 202 and continues with the work as it is fed, thereby forming a secure fastening for the leading thread end.

In order to improve the durability of the seams inserted by the present machine they are frequently formed with thread impregnated or coated with substances having adhesive properties. The addition of such substances to the thread not only alters its normal looping characteristics but tends to deposit and build up upon thread-engaging surfaces of the machine. It is common practice for the operator of conventional machines to apply a lubricant or a solvent manually to the looper from time to time. However, since the groove 202, the indentation 198 and the notch 192, in order to be effective are necessarily limited in Width, an occasional dousing with lubricant or solvent is often inadequate and may result in blocking of these narrow passages particularly when operating with heavily coated thread.

Accordingly as has been stated, an improved automatic lubricator has been provided for the looper in the illustrated machine, which automatic lubricator furnishes an adequate supply of lubricant to the beak of the looper and any surplus is thereafter wiped by the passage of the thread loops from the beak and distributed over the other thread-engaging surfaces thereof. The improved automatic lubricator thus acts as a cleaner for the looper and is connected with a thread cutter provided in the machine to apply lubricant to the looper beak each time the thread cutter is actuated.

As in the prior application the thread cutter comprises a blade similar to that indicated at 204 (see FIG. 39) secured to a supporting arm 206. The blade 204 has a sharpened edge arranged to engage the inner side of a needle loop just after it is entered by the looper 8.

The lubricator for the looper comprises a compressible pad 208 of lubricant absorbent material mounted on a resilient arm 209 secured to the arm 206 for the thread cutter in such a position that it is movable toward and from the path of the looper beak 10. The position of the looper beak 10 when the machine is brought to rest enables it to form an indentation of sufficient depth in the absorbent material of the pad that a surplus quantity of lubricant is squeezed onto the beak. Because of the construction of the thread cutter knife blade 204, and for the reason that the knife blade enters into the path of the looper beak, it is essential that the machine be stopped with the looper beak in a position to be engaged by the lubricator. Thus, the looper beak is stopped at a position remote from the point where it first engages a loop of thread carried by the needle and lubricant is squeezed onto the looper beak whenever the cutter is actuated to sever the thread at the end of a seam.

To prevent squeezing movement of the pad against the looper except when the looper beak is in stopped position where it will engage the pad squarely, means are provided, similar to that disclosed in my prior application, for preventing accidental operation of the thread cutter, comprising a triple lockout, one division of which consists of a set of connections actuated by the needle bar 4. This set of connections is in the form of an arm 210, shown in FIG. 1, having at its lower end a cam surface engaging a roll 212 on a handle lever 214 fulcrumed on a fixed pin 215 and connected for actuating the thread cutter. The arm 210 is locked against movement at all times except when .the needle bar 4 is in its highest position, as more fully described in inventors prior application, above identified. The handle lever 214 also carries a rod 216 extending downwardly to a position to engage a thread cutter arm 218 (FIG. 38). The arm 218 is secured to a horizontal shaft 220 (FIG. 41) having at its left end an enlargement to which is riveted the thread cutter arm 206, the arm 218 being held raised normally by a compression spring 222 engaging a lug 224 on the machine frame. Only when the needle bar 4 is in its highest position is it possible by these connections to depress the handle lever 214 and to actuate the thread cutter and looper lubricator.

The second and third lubricator and thread cutter lockouts act to prevent depression of the handle lever 214 by movement of an arm on a lock lever 226 into the path of the rod 216, and another arm of the lock lever 226 beneath the cutter actuating arm 218, as more fully described in my prior application. A horizontal arm of the lock lever 226 is pivotally connected to the upper end of a link 228 actuated downwardly in starting the machine in operation. By these connections the lubricator and thread cutter may be actuated only after the machine is stopped in a predetermined position and before the machine is started in operation upon a new shoe or other work piece.

As in the machine of the prior application, the illustrated machine is provided with means for releasing the work from clamping engagement by the presser feet 24 and 38 after the machine is brought to rest and for raising the presser feet for conveniently introducing a new work piece. Means for raising the presser feet includes a vertical slide 230, best shown in FIGS. 13 and 14, movable in a guideway 232 secured to the front side of the machine frame. The slide 230 is actuated through a link 234 pivotally connected between the upper end of the slide and a bell crank 236 rotatable on the frame of the machine. The bell crank 236 is connected through a link 238 with an arm 240 on a rotatable shaft 242 also carrying an arm 244 pivotally connected to a treadle actuated link 246. When it is desired to raise the presser feet from clamping engagement with the work, the treadle rod 246 is moved downwardly in the direction of the arrow in FIG. 13. At the same time that the presser feet are raised, the wrapper strip advancing claw 18 is raised from engagement with the wrapper strip on the ramp 72 to enable easy presentation of a new wrapper strip to the sewing point of the machine.

To raise the claw 18, the angle bar 96 of the claw assemblage (see FIG. 12) has its lower end beveled and is engaged by a wedge-shaped block 248 (see FIG. 14). The block 248 has a vertical slot through which passes a clamp screw 250 engaging threads in a horizontal block 252 secured to the slide 230, the arrangement being such that when the slide 230 is rm'sed, the wedge surface of the block 248 engages the beveled end of the bar 96 and swings the claw assemblage against the force of the spring 108 about the shoulder screw 102. When the treadle 1 13 rod 246 is moved upwardly the wedge block 248 is lowered and disengaged from the angle bar 96, permitting the spring 108 to draw the claw 18 yieldingly into feeding engagement with a wrapper strip on the ramp 72.

Although a work supporting block, according to the present invention, is valuable in combination with a sliplasted shoe sewing machine having a wrapper strip feeding device which impresses disturbing forces upon the needle and thread and thereby affects the reliability of the operation of the machine, it will be realized that subcombinations of the illustrated machine may advantageously be employed to improve the operation of sewing machines in which similar malfunctions are caused bythe characteristics of the work being performed. Furthermore, although a lubricating device is desirable in combination with my improved work supporting black for inserting seams with coated or treated thread it may be dispensed with when the possibility of accumulating foreign substances on the thread contacting surfaces is substantially reduced.

The nature and scope of the invention having been indicated, and particular embodiments having been described, what is claimed is:

1. A sewing machine for connecting together the parts of a slip lasted shoe including a wrapper strip, comprising an eye-pointed needle, a work supporting block having a needle reinforcing bore in the path of the needle and into which the needle enters after penetrating the shoe parts, looper means to which loops of needle thread are presented after being carried through the work by the needle, over-feeding strip advancing means ahead of and operating in time relationship with the needle for bulging the strip away from the work supporting block about the point of needle operation, presser foot means timed with the needle and with the strip advancing means for clamping the strip and the other shoe parts against the block thereby longitudinally compressing the strip, needle loop orienting means including a notch adjacent the looper means and communicating with the needle reinforcing bore to present each needle loop with certainty in looper means engaging position, thread storage means including an indentation for forcing kinks in the thread out of the needle eye during initial withdrawal of the needle after penetrating the shoe parts, lubricating means including a pad of compressible material positioned in touching engagement with the looper means during each sewing cycle, and means for moving the pad into squeezing engagement with the looper means when the machine is stopped for depositing upon the looper means a surplus quantity of lubricant, whereby the thread passing through the eye of the needle and moving through the shoe parts is protected against abrasion and the needle loop orienting notch and the thread storage indentation are maintained free of accumulations of foreign substances.

2. A sewing machine comprising a vertically reciprocated eye-pointed needle, a rotary looper provided with a loop entering beak movable across .the path of the needle, a work clamp including a work supporting block having a horizontal work engaging surface and a presser foot acting upon the work about the point of needle operation, thread locating means including a groove cut into the work engaging surface of the work supporting block at right angles to the line of the seam to be inserted, for retaining the leading end of the thread in the seam at a position along the seam line in advance of the point of needle operation, needle reinforcing means including a vertical needle confining bore formed in the work supporting block, in alignment with the needle, means for causing each loop of thread carried by the needle through the work to be forced through the needle eye beyond the diameter of the bore into the path of the looper, including a projection extending downwardly from the work supporting block in parallel relation with the bore, and loop deflecting means including a notch intersecting the wall of the bore and an outer surface of the block at the 14 side with the looper whereby the thread end is gripped by the first completed stitch of the seam and each needle loop is entered with certainty by the beak of the looper.

3. A sewing machine comprising stitch-forming and work-feeding devices including a straight eye-pointed needle and a looper having a loop entering beak movable across the path of the needle, a work supporting block located between the work and the looper and formed with a needle confining bore for reinforcing the needle, a projection from one edge of the bore extending from the needle confining bore toward the looper for causing each loop of thread carried by the needle through the work to be forced through the needle eye beyond the diameter of the bore into the path of the looper, and a loop deflecting notch intersecting the wall of the bore and an outer surface of the block at the side with the looper to guide the loop toward the looper and to hold it in a position where the looper will enter with certainty.

4. A sewing machine comprising stitch-forming and work-feeding devices including a straight eye-pointed needle and a looper having a loop entering beak movable across the path of the needle, a work supporting block located between the work and the looper and formed with a needle confining bore for reinforcing the needle, a projection from one edge of the bore extending from the needle confining block toward the looper for causing each loop of thread carried by the needle through the work to be forced through the needle eye beyond the diameter of the bore into the path of the looper, a loop deflecting notch intersecting the wall of the bore and an outer surface of the block at the side with the looper to guide the loop toward the looper and to hold it in a position where the looper will enter with certainty, and a thread storage indentation in the projection at the supply thread side of the needle and closer to the eye of the needle in its maximum work penetrating position than the deflecting notch, which indentation is adapted to receive a limited amount of thread displaced from contact with the needle to force kinks in the thread out of the needle eye.

5. A sewing machine comprising stitch-forming and Work-feeding devices including a straight eye-pointed needle and a looper having a loop entering beak movable across the path of the needle, a work supporting block located between the work and the looper and formed with a needle confining bore for reinforcing the needle, a projection from one edge of the bore extending from the needle confining block toward the looper for causing each loop of thread carried by the needle through the work to be forced through the needle eye beyond the diameter of the bore into the path of the looper, a loop deflecting notch intersecting the wall of the bore and an outer surface of the block at the side with the looper to guide the loop toward the looper and to hold it in a position where the looper will enter with certainty, and

a thread storage indentation in the projection at the supply thread side of the needle and closer to the eye of the needle in its maximum work penetrating position than the deflecting notch, which indentation is adapted to receive a limited amount of thread displaced from contact with the needle to force kinks in the thread out of the needle eye, the position of said loop deflecting notch being disposed about the axis of the bore toward'the line along which the seam is to be inserted by an angle of approximately 6. A sewing machine comprising stitch-forming and work-feeding devices including a straight eye-pointed needle and a looper having a loop entering beak movable across the path of the needle, a block located between the work and the looper and formed with a needle confining bore for reinforcing the needle, a projection from one edge of the bore extending from the needle confining block toward the looper for causing each loop of thread carried by the needle through the work to be forced through the needle eye beyond the diameter of the bore into the path of the looper, a loop deflecting notch intersecting the wall of the bore and an outer surface of the block at the side with the looper to guide the loop toward the looper and to hold it in a position where the looper will enter with certainty, a thread storage indentation in the projection at the supply thread side of the needle and closer to the eye of the needle in its maximum work penetrating position than the deflecting notch, which indentation is adapted to receive a limited amount of thread is displaced from contact with the needle to force kinks in the thread out of the needle eye, and an open axial slot entering the bore in the needle confining block and facing in the direction of work feed to free the thread running between the loop taker and the work, said slot being narrower than the diameter of the needle.

7. A sewing machine comprising an eye-pointed needle, a rotary looper provided with a loop entering beak movable across the path of the needle, a work supporting block located between the work and the looper, means for reinforcing the needle including a needle confining bore formed in the work supporting block, loop guiding means including a notch intersecting the wall of the bore and an outer surface on the block at the side with the looper whereby each loop of needle thread is held in position to be entered with certainty by the beak of the looper, and means for lubricating and cleaning the looper to insure free passage of the thread loops over the looper, including a compressible pad of lubricant absorbent material movable toward and from the path of the looper to engage the looper at a point remote from the notch in the Work supporting block and means for preventing squeezing engagement of the pad against the looper except when the looper beak is stopped at a position past the notch.

8. A work supporting block for use in a chain stitch sewing machine having an eye-pointed needle and a thread-enchaining looper, comprising needle re-inforcing means including a needle re-inforcing bore in alinement with the needle, means for orienting the leading end of the thread in a position to be gripped by the first completed stitch including a thread-receiving slot formed in the work contacting surface of the block in advance of the needle re-inforcing bore and extending angularly from the line of the seam, thread controlling means including a projection having a surface extending in close parallel relationship with the thread supply side of the needle in the deepest work-penetrating position of the needle, thread storage means including an indentation in the surface of the projection wherein a quantity of thread is stored at the supply side of the eye as the needle is withdrawn from the work, loop orienting means including a loop deflecting notch at the side of the needle with the looper, and a wall immediately outside the path of the looper, the wall and the slot together defining a loop receiving position in which each needle loop is entered with certainty by the looper.

9. A work-supporting block for use in a chain stitch sewing machine having an eye-pointed needle and a thread enchaining looper, comprising needle reinforcing means including a needle reinforcing bore in alinement with the needle, outlet means for already enchained loops including a slot narrower than the diameter of the needle, the outlet slot radiating from the bore in line with the seam, thread-controlling means including a projection having a surface extending in close parallel relationship with the thread supply side of the needle in the deepest workpenetrating position of the needle, thread storage means including an indentation in the surface of the projection substantially at right angles to the outlet slot wherein a quantity of thread is stored at the supply side of the eye as the needle is withdrawn from the work, the loop orienting means including a loop deflecting notch extending from the bore at the side of the needle With the looper and 16 a wall immediately outside the path of the looper, the wall and the slot together defining a loop receiving position in which each needle loop is entered with certainty by the looper.

10. A work supporting block for use in a chain stitch sewing machine having an eye-pointed needle and a rotary thread enchaining looper formed with a loop entering beak at one side of the needle, comprising needle reinforcing means including a needle reinforcing bore in alinement with the needle, means for orienting the leading end of the thread in a position to be gripped by the first completed stitch including a thread receiving slot formed in the work supporting surface of the block in advance of the needle reinforcing bore and extending angularly from the line of the seam, and a loop orienting means including a loop deflecting notch in communication with the needle reinforcing bore at the looper side of the needle and a wall immediately outside the path of the looper, the wall and the slot together defining a loop receiving position in which each needle loop is entered with certainty by the looper.

11. A shoe sewing machine comprising an eye-pointed needle, a rotary looper provided with a loop entering beak, a work clamp comprising a work supporting block and a presser foot acting on the work about the point of a needle operation, and thread locating means on the work supporting block for retaining the leading end of thread in a seam at a position along the line of the seam to be inserted in advance of the point of needle operation whereby the thread end is gripped by the first completed stitch in the seam.

12. A shoe sewing machine comprising an eye-pointed needle, a rotary looper provided with a loop entering beak, a Work clamp comprising a work supporting block and a presser foot acting on the work about the point of needle operation, and thread locating means including a groove cut into the work-engaging surface of the work supporting block at right angles to the line of the seam to be inserted for retaining the leading end of the thread in the seam at a position along the seam line in advance of the point of needle operation to insure that the thread end will be gripped by the first completed stitch in the seam.

13. A sewing machine for inserting chain stitch seams in work pieces subject to abrupt changes in the direction of feed, comprising a rotary thread enchaining looper, a straight eye-pointed needle, a stationary work supporting block below the needle, needle re-inforcing means including a bore in the block in alinement with the needle, loop orienting means including a loop deflecting notch extending from the bore to an outer surface of the block immediately above the path of the looper, and means for applying to the looper a thin film of lubricant for each revolution of the looper including a compressible pad of lubricant absorbent material and means for advancing the pad into squeezing engagement with the looper when the machine is stopped with the looper out of its loop engaging position.

14. A sewing machine for connecting together the parts of a slip lasted shoe including a wrapper strip, comprising an eye-pointed needle, a work supporting block having a needle reinforcing bore in the path of the needle and into which the needle enters after penetrating the shoe parts, looper means to which loops of needle thread are presented after being carried through the work by the needle, overfeeding strip advancing means ahead of and operating in time relationship with the needle for bulging the strip away from the work supporting block about the point of needle operation, presser foot means timed with the needle and with the strip advancing means for clamping the strip and the other shoe parts against the block thereby longitudinally compressing the strip, and needle loop orienting means including a notch adjacent the looper means and in communication with the needle 17 reinforcing bore to present each needle loop with certainty in position to be engaged by the looper means.

15. A sewing machine comprising an eye-pointed needle, a rotary looper provided with a needle loop entering beak movable in the path of the needle, a looper lubricator and cleaner comprising a compressible pad of lubricant absorbent material, and means for moving the pad toward and from the path of the looper at a position removed from the point where the looper first engages a loop of thread carried by the needle to cause the beak of the looper to form a depression of sufiicient depth in the absorbent material that a surplus quantity of the lubricant is squeezed onto the beak.

16. A sewing machine comprising a needle, a rotary looper provided with a needle loop entering beak, looper lubricator and cleaner means including a compressible pad of lubricant absorbent material, means for moving the pad toward and from the path of the looper at a position removed from the point where the looper first engages a loop of thread carried by the needle to cause the beak of the looper to form a depression of sufficient depth in the absorbent material that a surplus quantity of the lubricant is squeezed onto the beak, and means for preventing squeezing engagement of the pad against the looper except when the looper beak is stopped at a predetermined position.

17. A sewing machine comprising a needle, a rotary looper provided with a needle loop entering beak, a thread cutting knife, an arm for operating the knife mounted for movement in a direction to swing the knife into the path of the looper beak, and a compressible pad of lubricant absorbent material mounted on the knife supporting arm to cause the beak of the looper to form a depression of suflicient depth in the absorbent material that a surplus quantity of lubricant is squeezed out of the pad onto the beak whenever the knife is actuated to cut the thread.

18. A sewing machine comprising a needle, a rotary looper provided with a needle loop entering beak, a thread cutting knife, an arm for supporting the knife mounted for movement in a direction to swing the knife within the path of the looper beak, a resilient member secured to the arm, and a compressible pad of lubricant absorbent material mounted on the resilient member at a position where whenever the knife is actuated it contacts the beak within its path and where it is contacted by the looper beak during sewing without substantial depression of the pad.

19. A sewing machine for connecting together the parts of a slip lasted shoe including a wrapper strip, comprising an eye-pointed needle, a work supporting block having a needle reinforcing bore in the path of the needle and into which the needle enters after penetrating the shoe parts, looper means to which loops of needle thread are presented after being carried through the work by the needle, overfeeding strip advancing means ahead of and operated in time relationship with the needle for bulging the strip away from the work supporting block about the point of needle operation, presser foot means timed with the needle and with the strip advancing means for clamping the strip and the other shoe parts against the block thereby longitudinally compressing the strip, a projection on the block having a surface in close parallel relation with the thread supply side of the needle, and needle loop orienting means including a notch adjacent the looper means and in communication with the needle reinforcing bore to present each needle loop with certainty in looper means engaging position.

20. A sewing machine comprising an eye-pointed needle, a rotary looper provided with a loop entering beak movable across the path of the needle, a work supporting block between the work and the looper, the work supporting block having a needle confining bore, thread controlling means formed in the block comprising an indentation in communication with the bore and into which thread is stored for forcing kinks in the thread out of the needle eye during initial withdrawal of the needle after penetrating the work, and a notch intersecting the wall of the bore for directing a loop of needle thread into the path of the looper, the indentation and the notch being narrower than the diameter of the bore but wider than the thickness of the thread, and means for applying to the looper a lubricating and cleaning agent including a compressible pad of absorbent material positioned for touching engagement with the looper during each sewing cycle and movable into squeezing engagement with the looper at the end of a seam for depositing a surplus quantity of lubricating and cleaning agent whereby the agent picked up by the thread in moving over the looper and thereby carried to the narrow indentation and notch is effective to prevent the accumulation in the indentation and notch of foreign substances capable of rendering the machine inoperative.

References Cited in the file of this patent UNITED STATES PATENTS 1,080,877 Ashworth Dec. 9, 1913 1,111,907 Kiewicz Sept. 29, 1914 1,388,943 Gatchell Aug. 30, 1921 1,952,772 Newhall Mar. 27, 1934 1,999,251 Moranville Apr. 30, 1935 2,149,237 Barrett Feb. 28, 1939 2,192,166 Ashworth Mar. 5, 1940 2,442,222 Uccellini May 25, 1948 2,564,678 Dilger Aug. 21, 1951

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