US1909172A - Shoe sewing machine - Google Patents

Description

May 16, 1933. EPPLER 1,909,172

SHOE SEWING MACHINE Original Filed April 11, 1929 3 Sheets-Sheet l May 16, 1933;

A. EPPLER SHOE SEWING MACHINE 3 Sfieets-Sheet Original Filed April 11 1929 May 16, 1933. A. EPPLER SHOE SEWING MACHINE Original Filed April 11, 1929 3'Sheets-Sheet 3 Patented May. 16, 1933 UNITED STATES.

PATENT OFFICE ANDREW EPPLER, OF LYNN, MASSACHUSETTS, ASSIGNOR T0 UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, .A'CORPOR-ATION OF NEW JERSEY SHOE SEWING MACHINE Application filed April 11, 1929, Serial No. 354,201. Renewed July 15, 1932.

i The present invention has relation to sewing machines and more especially to inseam welt shoe sewing. machines of the type pro-- vided with a curved hook needle, adapted to form a chain stitch, and employed to sew the inseams of shoes.

' The invention refers particularly to machines of the said type which are designed to lay the chain in the channel of the insole, through entering the needle into the work fromthe channel side thereof. The placing of the chain in the channel has practical advantages over the more common practice of putting the chain upon the welt, as the doubled thread of the chain is less apt to cut the insole when made of soft material, and the single thread on the welt permits the out seam to be broughtin close to the upper without danger of cutting the inseams in the stitching, and at the same time allows the inseam to be put more nearly under the exact edge of the insole. The inseam thus made can be trimmed more closely,so that the ining its chain laid upon the welt by the use of stitch forming devices comprising a takeup and a thread finger, the take-up being timed to draw a loop ofthread tight around the shank of the needle while the needle is inthe work and the thread finger being timed to measure off thread between the looper and the work while the needle is through the. work iuorder to provide thread for the work side of the next loop during the retracting stroke of the needle. For the reasons hereinafter stated, however, this practice has not been followed in controlling the formation of the stitches of an inseam having its chain M laid in the channel although it is well recognized that an inseam formed by stitch forming devices comprising a take-up and athread finger is tighter, more uniform and more satisfactory than when the stitches are formed and tightened in any other manner.

When the chain is laid upon the welt, the needle pulls a loop of thread from the channel through the between substance and out from the welt, drawing the work side of its loop snugly into the bottom of the channel and pulling upon the thread against the resistance offered by the tension to tighten the stitch at this stage in its formation. Then the needle again enters the work,'and the take-up pulls upon the supply end in the opposite direction from the needle-pull, drawing the looptight about the shank of the needle and pulling the thread against the tension resistance to exert a stitch setting strain on the seam. The channel side of the between substance is always at a fixeddistance from the needle-hook when the needle is in the farthest retracted position, because the hottom of the channel is held against the chanlatter reaches its point of greatest retraction.

Hence, with stitches of equal length, the same amount of thread is drawn by the needle to tighten the stitch regardless of variations in the thickness ofithe between substance and a take-up and a thread finger having a uniform and unvarying action in giving up thread to the needle can be used withoutcausing reeving in the hook of the needle with consequent injury to and possible breakage of the thread.

When the chain is laid in the channel, how'- ever, the conditions are quite different. To lay the chain in the channel, it is necessary to enter the needle into the work from the channel side thereof. Then when the needle is retracted, it draws out from the channel a loop ofthread, and pulls the work side of such loop tight against the welt. This welt-surfaceof the work varies in distance from the channel guide in direct proportion to the variations in thickness of the between substance. Hence this welt-surface also varies in distance from the needle when the latter is at itsfarthest retracted position, in direct proportion to the thickness of the between substance. Consequently, to permit the needle toretract and tighten the stitch without causing the thread to reeve in the hook of the needle, it is necessary to provide the needle, during its retracting stroke, with more or less thread as the thickness of the between substance varies at various points in the circuit of the shoe. A take-up and thread finger arranged to operate as 1n a machine which the chain on the Welt will not accomplish this result since they always deliver to the needle the same amount of thread for all thicknesses of stock, as has been explained in the description of the op-- .eration of such a machine given above, and for this reason other means have been relied upon in previous attempts to improve the operation of machines laying the chain in the channel.

Having in mind the state of the art as above outlined, the object of the present invention is to provide a novel and improved inseam shoe sewing machine laying the chain in the channel and insuring a tight seam by pullingthe thread tight each time it is laid along either the welt or the channel side of the between substance without objectionable and preferably no reeving of the thread through the needle-hook.

To this end, the invention contemplates the provision in a chain stitch inseam shoe sewing machine having its curved hook needle arranged to enter the work from the channel side, of a'take-up and a thread finger acting, respectively, to draw tight the loop of thread around the shank of the needle while the needle is in the work, and to measure off thread between the looper and the work, constructed and arranged to give up to the needle during its retracting stroke an amount of thread varying with the thickness of the work. In its broader aspects, the invention contemplates the provision of any suitable construction, combination and arrangement of parts which enables the take-up and thread finger to operate in this manner. In the embodiment of the invention hereinafter specifically described, the desired result is socured by utilizing the thread finger to draw from the supply more or less thread as the work varies in thickness. T o avoid the necessity of additional parts, or complications in the construction and arrangement of mecha nism for actuating the thread finger, the desired action of the thread finger in pulling off thread is secured by arranging the thread finger to move in such a path that the increase and decrease in the thickness of the work and being movable in a path to cause In thesewin of a shoe. the variation in the thickness of thematerials through which the inseam passes .is due principally to the increased thickness at the toe portion of the shoe, and it has been found in actual practice that while the material increases in thickness at the toe portion of the shoe, it

is not of a solid nature at this point, being more or less pleated and having a tendency to pull away frim the shoulder of the insole. Consequently, during the sewing of the seam, this material is compressed and drawn tightly against the shoulder of the insole and for this reason, and also on account of the tendency of the thread to stretch slightly, the thread finger is arranged to draw from the supply an extra amount of thread less than twice the increase in the thickness of the material, which amount apparently would be required to enable the needle to properly tighten the stitch if the compressibility of the material and the stretch of the thread were not taken into account. To secure the best results both as to tightness of seam and freedom from reeving of the thread in the hook of the needle, the thread finger in the preferred form of the invention, is arranged to move in such a path as to cause a length of thread to be drawn from the supply which increases and decreases an amount substantially equal to increases and decreases in the thickness of the work.

In addition to the features of invention above referred to, the present invention also consists in the devices, combinations, and arrangements of parts'hcreinafter described and claimed.

While the invention is illustrated and described in connection with a machine for sewing Welt shoes, it is to be understood that the principles of the invention are not to be limited in their application to such machines. but are equally a plicable to turn shoe sew mg machines, an in other connections within the scope of the claims appended hereto.

The invention will be readily understood from the accompanying drawings illustrating a machine embodying the invention in its preferred form, and the following detailed description of the construction therein shown.

In the drawings, Fig. 1 is a side elevation of a welt shoe sewing machine including the improvements of the invention, certain parts not essential to the invention being omitted; Fig. 2 is a View in vertical section on line 22 of Fig. 1, looking in the direction of the arrows and showing in profile the cam which acts to release the needle tension; Figs. 3 to 7 illustrate diagrammatically in sequence the various steps in the cycle of making a stitch in the improved manner of the invention; 5 Fig. 8 shows on alarger scale, and in similar manner to Figs. 3 to 7, the manner in which the increase in thickness of the between substance increases the length of thread provided for the stitch.

Having reference to the drawings, the invention is shown embodied in an Eppler type Welter such as is shown and described in U. S. Patent No. 950,616, granted to the present inventor on March 1, 1910, for Shoe sewing machine. The present machine is organized to lay the chain-in thechannel, as in the patent, and in respect to the needle 1, the needle guide 2, the back gage 3, the welt guide 4, the looper 5, and the awl 6, andtheir actuating cams upon the cam disks 7, 8, and 9, the arrangement and operation are the same as in said patent, to which reference may be had for a full and complete description of these parts.

In accordance with the invention, there is combined with the said parts a thread measuring finger 10 having a forked extremity to engage the thread between the looper and its oint of emergence from the'last-formed nee le-hole in the work. This thread finger is secured in a carrier 11 pivotally mounted upon acap-screw 12 fixed in the frame of the machine, its attachmentto said carrier being effected by screws 13 whose shanks pass through oversized holes in the carrier 11,

ermitting adjustment of the thread-engaging end of the thread-finger to vary the effective radius on which the thread finger is swung and its distance from the surface of the work and consequently to vary the amplitude of its throw, the relation of its path to the work, and its resulting measuring or thread drawing effect. The thread finger moves back and forth in a plane at right angles tothe direction of feed of the work, its end engaging with the thread between the looper and the work and diverting it fromits straight line and producing a bend or loop by its upward and forward movement. The surface of the welt at one end of the needle hole last formed acts as one abutment in measuring off this bend or loop, while the lower end of the looper 5 acts as the other abutment. a

To actuate the thread finger, its carrier 11 is pivotally connected at 14: with a link 15 pivoted at 16 to the end of a cam lever 17 fulcrumed at 18 upon the machine frame and provided at its upper end with a cam roll upon a stud 19, the said cam roll engaging with a cam 20 shown in dotted lines, formed upon one end of the cam disk 9. This means of actuation imparts the aforesaid swingingmovement of the thread finger at right angles tothe direction of the-.feedof the work.

To facilitate the action of the thread finger in drawing aside a bend or loop of thread,it is desirable to relieve materially the tension uponthe thread while such thread finger is acting. This is effected by utilizingthe tension releasing device shown and described in the aforesaid U. S. Patent No. 950,616, and forming the subject-matter of U. S. Patent 'No. 1,011,177 also granted to the present inarm. This segment has two segmental surfaces both concentric with the pivot joining the segment to the arm 25, but of unequal radii, and said surfaces are held by a spring 27 in contact-with a circular disk 28 fixed concentrically upon the main shaft 29 of the machine. Between the two segme'ntalsurfaces there is applied to the segments a tooth which upon reverse rotation'of the shaft 29 after the stitching I has been finished, is brought into engagement with a gear 30 upon said shaft closely adjacent to the circular disk 28, the function of said tooth in its engage:

ment with the gear 30 being to bring the segmental surface having the longer radius into :contact withthe circular disk 28 to move and retain the arm 25 laterally away from the main shaft and straighten the toggle link 21, 22.

To utilize this mechanism just described to effect the periodic release of the tension at the point in each stitch-forming cycle when the thread finger 10 is acting to measure the thread for the next succeeding stitch, a cam 31 having the form shown in profile in Fig. 2,

is fixed upon the shaft 29 close beside the gear 30. Upon=the pivot 32 connecting said segment 26 with the arm 25 is pivotally mounted an arm 33 which. has a cam roll 34 upon a stud 35 fixed in said arm 33 intermediate its length. This cam roll is caused to follow the periphery of cam 31 by the action of the spring 27 previously referred to. The other end of the arm 33 is provided with an eye 36 through which is passed the shaft 29 in assemblingthe machine in order to support the arm in horizontal relation, the elongated shape ofsaid eye permitting the necessary lateral movement of arms 33 and25 effected by thecam 31 as it engages the cam roll 34 in the course of its rotation. The movement I its co-acting braking surface,'.an,d allows the i 'ing the link in adjusted relation.

thread finger to draw threadfromthe wax pot without having to overcomeany friction other than that incidental to drawing the thread through the stripper and-around the trucks over which it passes as led to the needle.

A second tension-imposing device is combinedwith the means just described for creating'and releasing the needle-tension, in order to assist the take-up 37 in drawing tightly against the channel side of the work a loop of thread surrounding the shank of the needle as the needle re-enters the work. This takeup tension mechanism comprising a brake shoe 38 adapted to be pressed against the periphery of a cylindrical portion 39 of the thread truck 23, its shank 40 being borne within a sleeve 41 upon one end of a bell crank lever 42, and it is pressed yieldingly against the periphery of said portion by means ofan expanding spiral spring 43 surrounding its shank and confined between lock nuts 44 applied to said shank and the proximate end of the sleeve 41. A collar 45 is aflixed to the protruding opposite end of the shank 40 by means ofa clamping screw, to

limit the movement of the shank within the sleeve '41 under the influence of spring 43, so that the brake shoe 38 may be lifted out of contact with the cylindrical portion 39 of the tension truck 23 by the movement of the bell crank 42. The bell crank 42 is pivotally mounted at 46 upon the frame of the machine and has its opposite extremity pivotally connected at 47 with a link which is joined at 48 with a cam lever 49 pivoted upon the machine frame at 50 and having at 51 a cam roll engaging with adisk cam 52 upon the shaft 29, said cam roll being pressed against the side of such cam by the action of a spring 53 coiled about the pivot 46 of the bell crank 42, having one of its ends engaged with the machine frame and the other with one arm of the bell crank 42. Means for adjusting the relation of the parts to vary the force and duration of the braking effect resulting from the engagement of the brake shoe 38 with its co-acting cylindrical surface 39 comprise devices for extending or shortening the length of the link between the bell crank and the cam lever 49, namely, the formation of the said link with a turn-buckle 54 uniting the oppositely-threaded rods 55, 56, and provided with lock nuts 57 for secur- The'take-up 37 comprises a thread truck rotating freely upon a cap screw 58 fixed in the end of an arm 59 upon a sleeve'60 which is rotatably mounted upon a stud 61 on the machine frame. At the other end of such sleeve is formed 'a short arm 62, to the extremity of which is connected at 63 a link 64 joined pivotally at 65 to the lower end of a cam lever 66 which is pivoted at 67 upon the machine frame and receives actuation from the cam disc 9 through engagement of such cam disc with a cam roll mounted upon a stud 69 at the upper end of saidcam lever.

To cause the cam rolls locatedrespectively at the upper ends of the take-up cam lever 66 1 and the thread finger cam lever 17 to follow their co-acting cams upon the cam disc 9, each of saidlevers is provided near its upper extremity with a pin 68 fixed therein and to these pins are attached the opposite ends of a contracting spiral spring 70, acting to force said cam rolls yieldingly against their respective cam surfaces.

The novel method of operation ofcthe organization described is illustrated diagranr matically in Figs. 3 to 7 inclusive. After the needle passes through the work and emerges from the welt side thereof, the thread finger 10 moves forward at right angles to the direction of feed of the work and engages the thread between the looper and the point where the thread emerges from the work at the last-formed needle hole therein. The thread finger thus pulls aside from the direct line between said looper and said needle hole a loop or bend of thread, which it retains while the looper is making its circuit of the needle and engaging thethread with the hook of said needle. During the thread lingers operation, 'both the needle tension and the take-up tension are released. The parts are now in the relation shown in Fig. 3, with the take-up 37 substantially half-way down in its thread-giving movement. Next the needle starts back through the work, the thread finger moving rearwardly out of engagement with the bend or loop which it has measured off for the needle,the looper moves aside, and the take-up descends a trifle farther to yield thread and prevent reeving of the thread through the hook of the needle with undesired shortening of the measured loop, all as shown in Fig. 4. As the needle recedes through the work, the needle tension is applied by means of the cam 31 and the parts controlling the tension truck 23 therefrom. The take-up continues its downward threaddelivering movement, but at a slightly slower rate than that at which the needle is drawing the supply end of its loop through the work, sothat as the needle reaches its point of farthest retraction as shown in Fig. 5, the tension on the two legs of the loop drawn through is substantially equal, the increase in the tension of the supply side achieved as just described serving to balance the tension on the work side of such loop caused by drawing the thread tightly against the welt side of 'the work and compressing the between substance by the pull of the needle. In thus pulling one side of the stitch tight against the welt side of the work, there is no apparent reevin g of the thread through the hook of the needle, owing to the balanced tension in both legsof the needle loop.

. vWith the needle tension still on,.the takeup tension is applied and the work is fed by the awl. As the needle approaches the channel and re-enters the work, the take-up 37 starts upwardly, pulling rearwardly on the supply end of the thread and shortening the needle loop vdrawn through the work as just describedso that it stands about the shank of the needle after its re-entry into the work, as shown in Fig. 6. Continuance of the upward movement of the take-up 37 with the needle tension and the take-up tension both still applied, results in drawing the needle loop tightly about the shank of the needle and against the channel surfaceof the. work, as shown in Fig. 7, and the titch-forming cycle has been completed. 7.

y The manner in which the invention provides for automatically compensating for increased thicknessof the between substance at various points in the circuit of the shoe will be clearly understood from an inspectionof Fig. 8. Thereinis shown oni a large scale the relation of the parts to the work after the thread finger 10 has acted to measure oil the bend or loop of thread for the next needle loop, and as the looper. is looping the thread into the hook of the needle, but before the thread fingerhas released such bend or loop. The length of thread entering into the work side of the next needle loop to be :drawn, through the work is equal .to thestretch of thread which extends from the welt surface ofthe work at E, up over the thread finger at B, and-to the hook of the needle at C. When the needle is retracted, with the parts in proper adjustment, this length of thread will be ,just adequate to carry the needle back to its point of farthest retraction without reeving through the hook of the needle, the tension on this length of thread as the needle draws it tight against the welt side of the work being balanced as aforesaid by the needle-tension applied to the supply side of the loop and the lagging of the giv-.

ing-up action of the take-up 37 In the event that the work increases in thickness, as for example, to an extent such as would bring the surface of the welt tothe point D, it will be seen that the length of thread from the channel at A .to the hook of the needle at C will have been increased by the length ED, the thread entering into the making of the work-side of the next needle loop following the path DBC. The length of the bend or loop EBC held aside by the thread finger differs in no substantial extent from .thelength D-BC hence, the thread finger draws aside substantially the same length of thread with thick stock as with thin. But, on thick stock, the needlehook, after engaging the thread, travels a less distancebefore entering the stock due to the fact that the welt surface is nearer the source of supply, and consequently more of the thread given up by the thread finger and take-up, is available for, the needle loop during the 6on-v tinued retracting movement of the needle. On thick stock, the needle hook as it is circled by the looper engages the thread v farther away from the channel than on thin, though the thread finger and looper have each a constant throw, that is, the length of, thread between the needle hook and the channel 7. is greater with thick stock than with thin stock, and this increase in the length of thread between channel and needle hook is secured by using the looper as one abutment about which:

the thread is bent aside by the thread finger, and by using as the other abutment the surface of the welt, which varies its distance from the channel in direct proportion to the thickness of the stock. By the novel arrangement of the thread finger ,withrespect to the surface of the work, as indicated inthe drawings, the thread finger is made to add to'the work side of the needle-loop a length ofthread equivalent to the worksincrease in thickness at the exact point being stitched.

There is an increase in the length of the thread drawn'into the system, as -measured from the tension to the channel guide, as the i between the channel and the looper with thick stock than that, A-,EB C, followed with thin stock. As stated. hereinbefore, the

uncompacted state of the'between substance ermits it to be compressed to such an extent 1y the work side of the needleloop when the latter is drawn tight by the needle as in Fig. 5, as to make this amount in practice a complete and accurate compensation which disposes of all observable reeving in the hook of the needle. 7

Since the variation in thickness of the work does not vary the position of the channel side I of the work, the needle loop is always drawn out of the channel thesame distance, and

when the needle re-enters the work, the takeup, having a constant throw, retrieves the same amount of thread from the work in drawingthe needle loop tight around the shank of the needle and against the channel side of the work. The movement of the take-up continuesafter'tightening this loop, and in completing its working stroke it draws fromthe supply a length of thread entering into the formationot the next succeeding stitch, which length .as drawn by the take-up is also always the same. The action of the thread finger, in its peculiar eo-operation with the abutment formed by the surface of the welt, causes it to add to this length drawn bythe take-up an amount which it draws from thesupply with'both tensions 0H, and to proportion this added amount to the thickness of the Work at the point being stitched.

The nature and scope ofthe invention havingbeen indicated andamechanism embod ing the invention having been specifical y described, what is claimed is:

1. A hook needle, chain stitch inseam shoe sewing machine having, in combination, a n'eedle arranged to enter the work from the channel side thereof and during its retract ingist'roke to exert a stitch tightening strain on the thread, a take-up acting to draw tight a loop of thread around the shank of the needle while the needle is in the work, a looper, and'a thread finger movabletransversely to the stretchof the thread from the looper to the work in apath to cause alength of thread to be 'dr'awn from the supply increasing and decreasing an amount substantially equal to increases and decreases in the thickness of the work.

2. A hook needle, chain stitch, inseam shoe sewing machine having, in combination,- a needle arrangedto enter the work from the channel side thereofand during'its retracting stroke toeXert a stitch tightening strain on the thread, a take-up acting to draw tight a loop ofthread around'the shank of the needle while the needle is in the work, a looper, and a thread finger movable transversely to the stretch of the thread from the looper to the work in a path to cause a length of thread'to be drawnfrom the supply varying with the thickness of the-work},

3. i A hook needle, chain stitch, inseam shoe sewing machine having, a in combination, a needlearrangedto enter the work from the channel side thereof and'during its retractingistroketo exert a stitch'tightening strain on' the thread, a take-up acting to draw tight a loop of thread around the shank of-the needle while the needle is in the work, a looper, a tl'iread'finger engaging the thread between the workand the looper, a thread tension mechanism and means for controlling said mechanism to release the tension on the thread during the thread drawing movement of the thread finger.

4; A hook needle, chain stitch, inseam shoe sewing: machine having, in combination, a needle arrangedto enter the work from the channel side thereof and duringits retractingisti'oke to exert a stitch tightening strain on-th'e thread, a-take-up acting to draw tight a": loop of thread around the shank of the needle' while the needle is in-the work, a looper, athreadfinger engaging the thread between the work and the looper, a thread tensionmechanism, means for controlling the thread tension' mechanism to release the tension 'on the thread during the thread drawing movement 'of'the thread finger, to apply a tensionto the thread during the retraction of the needle, and to apply a heavier tension to the thread during the pull of the take-up.

5. A hookneedle, chain stitch, inseam shoe sewing machine having, in combination, a.

needle arrangedto enter the work from the channel side thereofand during its retracting stroke to exert a stitch tightening strain on the thread, a take-up acting to draw tight a loop ofthread around the shank of the needle while the needle is in the work, a looper and a thread finger engaging the thread between the work and the looper arranged to co-act with the work during its thread drawing movement to draw from the supply a length of threadvarying with the thickness of the work.

6. A hook needle, cham stitch, inseam shoe sewing machine having, in combmation, a

needle arranged to enter the work from the r channel side thereofa'nd during its retracting stroke to exert a stitch tightening strain on the thread, a take-up acting to draw tight a loop of thread around the shank oft-he needle while the needle is in the work, a looper, and V a thread finger engaging thethread between the looper and the adjacent surface of the work and movable in apath to cause said surface to cooperate, through its relative shift in position'due to variations in thicknessof f the work, with said thread finger to draw from the supplyvarying amounts ofthread to compensate for such variations in thick .ness.

7. A hookneedlc, chain stitch, inseam shoe a loop of thread around the shankof the needle while'the needle is in the work and thereafter pull a uniform amount of thread from the supply regardless of variations in the thickness .of the work, a looper, and a thread finger movable transversely to the stretch of the thread from the looper to the work acting'after the thread pulling movement ofthe take-up to pull from the supply an amount'of thread varying with the thick- 2 nessof the work.

8. A hook needle, chain stitch, inseam shoe sewing machine having, in combination, a needle arranged to enter the work from the channel side thereof, a take-up acting to i draw tight a loop ofthread around the shank ofthe needle while'the needle is in the work and to draw thread from the supply, a looper, anda thread finger engagingthe thread between the work and the looper, said take-up and thread finger cooperating to draw a length of' thread from the supply varying with the thickness ofthe work an amount permitting the needle to tighten the stitch without'reeving'of the thread in the needlehook.

9. A hook needle, chain stitch, inseam shoe sewing machine having, in combination, a needle arranged to enter the work from the channel side thereof and during its retract ing stroke to exert a stitch tightening strain on the thread, a take-up acting to draw tight a loop of thread around the shank of the needle while the needle is in the work and to draw thread from the supply, a looper, and a thread finger engaging the thread between the work and the looper, said take-up and thread finger cooperating to draw from the supply a length of thread increasing and decreasing an amount substantially equal to increases and decreasesin the thickness of the work.

10. A hook needle, chain stitch, inseam shoe sewing machine having, in combination, a needle arranged to enter the work from the channel side thereof and during its retracting stroke to exert a stitch tightening strain on the thread, a take-up acting to draw tight a loop of thread around the shank of the needle while the needle is in the work, a looper, a thread finger engaging the thread between the work and the looper, and means for actuating the take-up and thread finger to give up to the needle during its retracting stroke and after the needle hook enters the work an amount of thread varying with the thickness of the work.

11. A hook needle, chain stitch, inseam shoe sewing machine having, in combination, a needle and a channel guide located on one side of the work, said needle acting during its retracting stroke to exert a stitch tightening strainon the thread, a take-up acting to pull tight a loop of thread about the shank of the needle while the latter is in the work, and a looper and thread finger upon the opposite side of the work and coacting with the surface of the work to vary the length of thread between the channel and the hook of the needle at the completion of the looping operation, in proportion to variations in the thickness of the work. i

12. A hook needle, chain stitch, inseam shoe sewing machine having, in combination, a needle and a channel guide located on one side of the work, said needle acting during its retracting stroke to exert a stitch tightening strain on the thread, a take-up acting to pull tight a loop of thread about the shank of the needle while the latter is in the work, and a looper and thread finger upon the opposite side of the work and coacting to vary the point in the length of the thread extend,- ing from the channel to the looper at which the hook of the needle engages the thread priorto the needles retraction, said variation being proportionate to the thickness of the work.

13. A hook needle, chain stitch, inseam shoe sewing machine having, in combination, a

needle and a channel guide located on one side of the work, said needle acting during its retracting stroke to exert a stitch tightening strain on the thread, a take-up acting to pull tight a loop of thread about the shank of the needle while the latter is inthe work and a looper and thread finger upon the opposite side of the work and coacting with the work to Vary the length of the loop of thread given to the needle during its retracting stroke and after the needle hook enters the work in proportion to the thickness of the work.

In testimony whereof I have signed my name to this specification.

ANDREW EPPLER.

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