US1592434A - Sewing machine - Google Patents

Description

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July 13,1926. 1,592,434

D. BELCHER SEWING MACHINE yOriginal Filed Jan. 29. 1921 5 Sheets-Sheet 2 July 13 1926.

D. BELCHER SEWING MACHINE Original Filed Jan. 29. 1921 5 Sheets-Shogi. 3

July 13 1926.

D. BELCHER SEWING MACHINE origina Filed Jan. 29. 1921 5 Sheets-Sheet 4 July 13 1926. 1,592,434

D. BELCHER SEWING MACHINE Original Filed Jan. 29, 1921 5 Sheets-Sheet 5 Patented July 13, 1926.

UNITED STATES PATENT OFFICE.-

DANIEL BBLCHER, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR T BEMIS BRO. BAG OOM- PANY, OF ST. LOUIS, MISSOURI, A CORPORATION 0F MISSOURI. i

` SEWING MACHINE. 'v T Original application illed January 29, 1921, Serial No. 440,927. Divided and this application illed January 14, 1924.

This invention relates toimprovements in sewing machines and has for its primary object a machine which will make a strong close lying stitch and at the same time save a considerable amount of thread. v

A. further obj-ect' is to construct a sewing machine which is provided with a means to prevent backlash or formation of a double loop of needle thread at the needle point. lVhere this double loop forms it becomes entangled with the looper and the needle .thread is torn thereby causing a rejection of many sewed articles. By preventing the formation of a double loop this trouble is eliminated. f

A still further object is to construct a sewing machine for forming thread saving stitches which is provided with aplurality of devices such as an intermittent threadlock for the needle thread, a slack take-up for the needle thread, and a slack pull-up and releasing device for the looper thread by means of which a stitch is formed in whic the looper thread lies close to the fabric and practically no needle thread is exposed on -the looper side of the fabric. The entire stitch on the looper side being extremely smooth and lying close to the fabric so that there will be substantially no give to the seam and the various layers of fabric rmly united together.

This application is a division of the application filed by me January 29, 1921, Serial o. 440,927 for improvements in the method of formin stitches.

Fig. 1 is a front elevation of a portion of a sewing machine showing my improvements thereon; e

Fig. 2 isa rea-r elevation of the same;

Fig. 31s a top lan view of the same;

Fig. 4 is an end) elevation of the same;

Fig. 5 is an enlarged plan view of the looper thread take-up cam;

Fig. 6 is a side elevation of the same;

Fig. 7 is a top plan view of the supporty glade use of for the pan tension on the needle T ar; A ,i

Fig. 8 isan enlarged vertical cross section of the intermittent thread lock;

e Fig. 9 is, an enlarged end view of the stud onwhich the thread lock operates;

Figi y10 isan enlarged 'face view of the Serial No. 685,976.

tafiionary cam made use of in the thread Fig. 11 is an enlarged face view of the movable cam made use of in the needle thread lock; l

Fig. l2 is an enlarged vertical section of the rocking mechanism employed for operating the looper;

Figs. 13, 14, 15, 16, 17 and 1s are da! grammatic sectional views of the looper threadtake-up cam showing the same in various positions during its operation;

- Fig. 19 is an enlarged plan view of the looper side 'of the stitch with a portion of the needle thread broken away and in section; and v- Fig. 20 is a vertical section taken through the fabric adjacent the stitch and showing the position'of the needle and looper threads.

In the construction of my device I employ a machine-head comprising a base having an integrally formed arm 26. The arm 26 has an integrally formed bearing '27 through which a shaft 28 extends.- The base 25 is provided adjacent its forward end with an integrali formed upwardly projecting lug 29 in which the shaft 28y is also journaled or supported.

A The shaft 28 extends through the arm 26 and has located upon its project-ing end a sheave wheel 30 and between the sheave wheel 30 and arm 26 is located an eccentric 31. The eccentric 31 may be formed integral with the wheel 30, it may be separate and securedeither on the shaft 28 or to the sheave wheel 30, or it may be formed integral with the shaft. This construction of cam resting entirely with the manufacturer as either type of cam will not affect the operationof my device at all.

Surrounding the eccentric 31 is an eccentric strap 32 which has secured thereto one end of a connecting rod 33, the opposite end of the connectin `rod is secured in a socket 34 which has a Iiearing 35 formed integral with its upper end. Mounted in the bearing 35 is one portion of a balljoint 36, the other portion of this joint is firmly secured to the projection 37 formed integral with the needie bar lever 38. The needle bar lever 38 is ivtally secured intermediate its ends to t e arm 26 at the point indicated by the numeral '39. Secured xto the end/10 of the needle bar lever are links 41, which links are in turn secured to a lug 42. This lug is in turn firmly secured to the needle bar 43 so that upon rocking of the lever 38 the needle bar is reciprocated up and down. Formed integral'with the arm 26 are bearings 44 through which the needle bar extends and which serve as guides for the bar.

The needle bar has its lowerend tapered and split, this tapered split end is provided with screw threads 45 over which theI nut 46 is adapted to be secured. The lower portion of the needle bar is also provided with av bore for the reception of the upper end of the needle 47 and when the needle is placed in this bore and the nut 46 tightened the lower end of the needle bar will be pressed together thus securely holding the needle 47 in place.

The end 48 of the needle bar lever 38 is provided with a stud 49 to which is secured a bearing 50 which has secured thereto one end of the connecting rod 51. The opposite end of this rod is secured to a similar bearing 52, which bearing is secured to the stud or pivot 53. The stud 53 is in turn secured to the looper 54.

Formed integral with the arm 26 is a projection 55 through which extends a screw threaded rod or bar 57, and on this bar are loosely mounted the pan tensions 58 and 59. The tension 58 being for the needle thread and the tension 59 for the looper thread. These tensions are regulated by means of a thumb nut 60 and coil spring 61 and when once regulated for the particular kind of work, remain constant.

Extending through the projection 55 is a bar 62 which is provided adjacent each end with openings, these openings act as guides for the needle and looper threads, keeping them in alinement with their respective tensions. v

Secured to the needle bar lever 38 is a bifurcated arm 63 which has located in its bifurcation the arm 64 of the movable cam member 65. The cam member is provided with inclined faces 66 which contact with the inclined faces 67 of the stationary cam member 68. The movable cam member 65 is provided with a circular opening 69 which is adapted to fit over the cylindrical portion 70 of the stud 71. The stud 7l is secured in a bracket 72 which is firmly attached to the arm 26. The Stationary cam 68 is provided with a square opening 73 which is adapted to fit over the square portion 74 of the stud 71 and thus prevent the cam member from turning. The stud 71 is secured in the bracket by means of the nut 75 and screw 76. -My purpose of thus securing the stud is that the nut 75 will prevent any longitudinal movement of the stud, while the screw 76 will prevent any turning. The prevention of turning of the Stud 7l is very essential as the turning of the stud will cause a variation in the degree of tightness between the pans 77 and 78 which would cause them to exert more or less pressure on the needlethread by the operation of the needle bar lever. The tension exerted by the pans 77 and 78 is intermittent but is made adjustable so as to accommodate diiferent sizes or thicknesses of thread and also to permit adjustment for various kinds of work. The

regulation of the tightness between the pans 77 and 78 is regulated in the following manner z-If the stud is turned so that the stationary cam member carried by the square portion thereof revolvesl toward the needle bar or counter-clockwise, the oscillation of the movable member will cause it to ride up on the cam surfaces of the stationary member lto a greater degree and consequently cause more movement of the pans 77 and 78 than if the stud were revolved in the opposite direction. In other words, turning the stud counter-clockwise the highest point of the stationary and movable cams are more widely separated than if the stud were revolved clockwise. The riding of the cam surfaces upon veach -other and the consequent binding of the pans 77 and 78 on the needle thread 7 9 is occasioned by the reciprocating movement of the bifurcated `bar 63 due to the movement of the needle bar lever. This reciprocating movement of the bar 63 is in turn communicated to the movable cam 65, which due to the fact that the stationary cam 68 cannot rotate will cause the cam faces to ride up on each other and force the pans 77 and 78 towards each other thus binding the needle thread between the two pans. Secured to the arm 26 is a guide 80, the purpose of which is to assist in guiding the thread from the pan tension 58 between the pans 77 and 78. The needle bar lever is also provided with la loop 81, the purpose of which is to assist in pulling off suflicient needle Vthread for the next stitch and also to assist as a 'pull-up for the needle thread during a portion of the stitch formation. i

Near the upper end of the needle bar 43 is a loop 82 through which the needle thread 79 passes.. After passing through the loop 82 the thread is then passed through the pan tension 83 which is secured to the needle bar 43. The stud 84 on which the pans 85 aa'e secured is provided with a circular o ening 86, this opening has a slot 87 exten ing to the outer surface of the stud 84 so that the thread can be readily inserted therein without the necessity of spreading the pans apart and pushing the end of the needle thread through the opening 86. After the thread has been thus inserted the openin acts as a guide for the needle thread an holds it between the disks of the pan tension. After bein threaded through this pan tension, whc remains constant atv al1 times, the lower end of the needle thread is then insertedV through the eye of the needle 47.

Secured to the upper portion of the arm 26 and preferably extending on both sides of the needle bar 43 is a vertically adjustable member 88. Thismember co-acts with the loop 81 carried by the needle bar to act as a pull-up on that strand of needle thread adj acent the Vintermittent tension. vThe vertical adjustment of the member 88 regulates the starting point of the pull-up on the needle thread and consequently the amount of such pull-up. And in order to prevent the needle thread from slipping olf of the member 88 an upturned ortion 89 is provided. The adjust-ment o plished by loosening the set screw 140 and raising or lowering the post 141. The drawing up is accomplished in the following manner-As the loop 82 passes downward past the extending portion of the member 88, the extending portion of the member 88 prevents the needle thread from traveling downward with the movement of the needle bar and due to the fact .that at this period the needle thread has -been clamped by the intermittent thread lock no more thread can be fed through the needle and consequently a pulling up on the Strand of thread adjacent the intermittent lock will result. This operation will be explained in detail later.

On the end of the shaft 28 which projects through the bearing or support 29 is secured a disk 91 which is provided with a diainetrically extending slot 92 which is T-shaped in cross sectionand in which is mounted the head of a bolt 93. On the shank of this bolt is secured one end of a link 94, its opposite end being secured in the arm 95 of the rocking frame 96. The rocking frame is provided on its ylower end with bosses 97 through which a shaft 98 eX- tends, the ends of which are mounted in bearings 99 formed integral with the base 25. The upper portion of the rocking frame is provided with bearings- 100 which support a shaft ,101. The shaft 101 is secured in the bearings 100 against longitudinal movement and in turn supports the arm 102 to which the toothed feeder 103 is secured.

It will be noted from Fig. 4 that the link 94 is eccentrically and adjustably mounted in the disk 91. This eccentric mounting imparts a rocking motion to the frame 96, which rocking motion is in turn converted into a reciprocating motion for the feeder 103.

The T-shaped slot prevents the head of the bolt 93 from coming out of the disk. The head of this bolt is provided with a screw threaded bore which receives the thread portion of a screw 104. The purpose of this screw 'is to vary the eccentricit'y of the member 88 is accom' the link 94 and consequently the reciprocating movement of the feeder 103 which varies the amount of fabric fed or rather the rate of feed and consequently the length of the stitch so that either a coarse or fine stitch can be attained.

Formed integral with the base 25 are proi ing as a pivot for the looper 54. Secured on the shaft 107 and located between the lugs and 106 is a bifurcated member or fork 111, its bifurcation straddling the cam 112 which is secured to the shaft 28 and rotates therewith. This cam and bifurcated member impart an oscillating motion to the looper 54. That is, cause the loopcr to rock laterally bringing the looper first to the front and then to the rear of the needle as it penetrates the fabric being sewed.

Formed integral with the base 25 is an upwardly projecting casting 113 to which is pivotally secured a U-shaped thread `uide 114, which guide is also capable of adjustment up and down by means of the screw 138. This screw iscapable of being raised and lowered and supports one arm of the thread guide 114. The arm being held in constant contact with the screw head by means of the spring 142 which bears against the outwardly bent portion 143 of the U- shaped guide 114. This adjustment is for the purpose of regulating the amount of slack taken up and also the time at which the looper thread 115 contacts with the loopcr thread take-up cam. The thread guide 114 is provided adjacent its open endv with openings through which the loopcr thread 115 is passed. The thread guide 114 is for the purpose of holding the looper thread over the looper thread take-up cam 116 which is-mounted on the shaft 28 and rotates therewith. The looper thread cam is provided with a central groove 117 into which the thread remover 118 extends.

jection 113. Secured to the projection 113 and extending above the thread remover 118 is a hook 119, the purpose of which is to retain the thread during a certain portion of the movement of the cam 116. The cam 116 is provided with faces 120, 121, 122, 123. 124 and 125, the purpose of these faces will be explained in detail later.

The projections or lugs 29 and 106 are provided on their-upper ends with plane surfaces 126 and in these surfaces are formed The thread remover is also securedto the proscrew threaded openings for the purpose of securing a plate (not shown in the drawings) thereto, which plate is adapted to act as ay rest for the work.

The base 25 is also provided with a projecting lug 127 to which a cover (not shown) is hingedly secured. The purpose of this cover is to enclose the mechanism which operates the rocker frame 95 but still allow ready access thereto for adjusting purposes.

Mounted in the arm 26 is a presser foot bar 128 to which the presser foot 129 is se-v cured. The presser bar 128 has secured thereto a projecting lug 130 on which one end of a spring 131 rests, the opposite end of the spring is secured to the projecting lug 55. The desired pressure of the presser foot is imparted to the spring by means of the adjusting screw 132. The presser foot 129 and bar 128 are raised by means of the eccentric-lever 133. The purpose of raising the presser foot is to permit the desired ad justment of the various tensions and for threading the looper as the machine can then be easily turned by hand so that the various operating parts will assume their necessary positions for these purposes. This raising of the presser foot is also necessary for the insertion of new work. The raising of the presser foot is accomplished by raising the eccentric lever 133 which contacts with the stud 134 which is carried by the presser foot bar 128.

In order to keep the bar 128 and presser foot 129 from turning I make use of a sliding shaft 135 which is connected to the bar 128 by means of the stud 136. The shaft 135 is spaced apart from the bar 128 and prevents through its connection any turning of the presser foot when employing the eccentric lever 133 to raise the foot and also holding the presser foot in proper alinement while the work is passing through the machine.

Secured to the base 25 is a guide 137, this guide is for the purpose of having the looper thread passed therethrough from the pan tension 59 so that it will be properly guided to the thread guide 114 without coming in contact with any of the working parts otl the looper mechanism.

The operation of my device is as follows- The machine is first threaded in the following manner-the needle thread 79 is first passed through the opening in the bar 62, this opening being the one located to the front of the machine. The thread is then passed down underneath the bar 57 and then between the pans 58 and the pan tension, from there the thread passes through the thread guide 80. The thread is then passed between the pans 77 andV 78 and through the loop 81 after which it is passed through the loop 82 carried by the needle bar, thence downward through the pan tension 830erried by the needle bar, and lastly threaded through the eye of the needle.

The looper thread 115 is passed through the opening in the bar 62 to the rear of the machine, from there is inserted in the pan tension 59, after which it passes downward and is inserted through the guide 137. It then is passed forward and passes through the openings formed in the thread guide 114, after which it is passed or threaded through the looper 54;.

The machine is preferably driven by means of a belt which is passed around the sheave wheel 30 and which is driven from any suitable source of power, such as a line vfoot lowered, after which the machine is operated for a few stitches, the stitches are new examined and the pan tensions and intermittent tension so regulated as to give the proper degree of tightness to the threads and stitch. After these adjustments have been made the device is ready for its operation.

The various sequential steps will be described commencing with the needle bar raised to its highest point, after which the first step will be the movement of the needle bar lever in such a manner as to carry the needle bar and needle downward with it so as to penetrate the material being sewed. This operation carries the needle thread through the fabric in the form of a loop and at the same time commences to operate the intermittent lock. This lock gradually tightens on to the thread until the lowest point of travel on the needle bar lever has been reached, and during the latter portion of this tightening of the intermittent or thread lock, the loop carried by the needle bar passes by the needle thread pull-up 88 which imparts a retrograde movement -to that strand of needle thread between the intermittent tension and the needle point. This upwardpull draws up the previously formed stitch and seats it tightly. 1

The various movements of the looper thread are as follows--Just as the needle is ready to descend, the talre-up cam is in the position illustrated in Fig. 14 and as the needle commences to descend the looper thread lying on the face 125 of the cam 117, this thread is carried upward by the face 125 as illustrated in Fig. 14 and isforced along this face by means of the thread remover 118 until it rides on the face 120. The looper thread slides along the face 120 until it comes in contact with the hook 119 Where it relnains until the face 120 is clear of the hook. The looper thread is then permitted to pass the hook 119 and fall down on the face 121 along which it travels until it comes to the face 122 which picks it up and carries it upward until it again contacts with the thread remover 118. The additional projection formed by the cam faces 122 and 123 then exerts an additional pullup and thereby places a tension on the looper thread whichv ldraws it tightly against the underside of the fabric just at the time that the needle thread is being acted on by the needle thread pull-up. The thread then slides along the face123 but is held by the hook 119 until the face 124 assumes the position shown `in Fig. 18.l after which it will slide under the hook 119 and come to rest a ain on the face 125 after which the operation is repeated.

The operation of the machine or in other words the formation of the stitch is as follows-Just as the needle is ready to 4descend the looper and cam are in the positions shown in Figs. 3 and 14, after the needle commences todescend the looper commences to move forward and by the time the needle is ready to rise the looper passes through the loop of needle thread carrying with 1t a loop of loo r thread. At this point the looper is to thi rear of the needle. Phe needle next is withdrawn from the fabric and the looper swings forward and at the same time moves backward thus releasing the loop of needle thread which it has previously caught up. The needle and needle thread now descend through a loop of looper thread which has been caught by the previous loop of needle thread and as the needle continues to descend the previ.- ous loop of needle thread. is drawn up taut against the underside of the fabric. Just at the point of drawing up of the needle thread the looper has been pulled back and oscillated so that it isY to the rear of the needle thread and when the needle commences to be withdrawn again thus forniing a loop of needle thread below the fabric the looper and looper thread again enter this newly formed loop, after which the previous operation is repeated.

It is of course to be understood that as soon as the needle has been raised out of the material being sewed, the feeding mechanism causes the feeder plate to grip the Work and carry it forward under the presser foot a suliicient distance to form the stitch.

The saving of thread is illustrated in the following example, the sizes of threads employed being those commonly used for bag sewing- The thread used is 5 ply for the needle thread and 3 ply for the looper thread and the basis of measurement o thread being a one ply thread so that one foot of needle thread will be equivalent to 5 feet of one ply thread, and one foot of looper thread equivalent ,to 3 feet of one ply thread. p In the old stitch made by machines as used at `presentfor bag sewing there are approximately 3.5 of 5 ply thread used for every foot of sewing. This is equivalent to 17.5 feet of one ply thread, while approximately 1.5 feet of 3 ply thread is used for the same amount of sewing,-tliis is the equivalent of 4.5 feet of oneply thread, making in all a total of 22 feet of one ply thread.

In the stitch as made by my improved method and attachments I use approximately 1.5 feet of 5 ply or 7.5 feet of one ply thread in every foot of sewing, while approximately 3.5 feet of 3 ply thread are used in every foot, or 10.5 feet of one ply thread. This makes a total of 18 feet of one ply thread used by my device in sewing one foot of fabric, as against 22 feet of one ply thread in the old device. This means a saving of 4 feet of one ply thread in every foot of sewing, which will run into a considerable amount in the course of a day when it is figured that each machine turns (ut several thousand completed articles a It will be noted from Figs. 19 and 20 that one strand of looper thread passes around the entire loop of needle thread projecting below the fabric, one strand of looper thread passes through the loop of needle thread,

and one strand of looper thread is bent around one of the strands of needle thread. The last two mentioned strands f looper thread being below the first mentioned strand of looper thread thus holding it tightly against the fabric. This makes a total of three strands of looper thread between adjacent loops of needle thread and as illustiated in Fig. 20 a portion of the looper thread is partially imbedded in the fabric.

The distance to which the looper thread is imbedded depending on the kind of material and weave used for the .bags sewed.

It will also be noted that two strands of looper thread lie parallel to each other so that each loop of needle thread embraces two strands of looper thread. This has a tendency to spread out the loop of needle thread and thus make a stronger stitch, due tothe fact that the needle thread loop is spread out over two strands of looper thread which lie side by side. It has been found by actual test that the looper thread acts as a knife and cuts the needle thread when the saine is pulled up, so by having two strands of looper thread lying side by side and the loop of needle thread passing over both of these strands the cutting tendency of the looper thread is considerably reduced because instead of only a round surface bearing against the needle thread loop, a wide bearing surface is obtained and therefore the cutting tendency greatly reduced.

During the operation of my device the pan tension carried by the needle bar holds the needle thread taut between the eye of the needle and the tension. My purpose in placing this pan tension on the needlebar is because I have found that without tlns tension the needle thread will at times become slack and hang below the point of the needle so as to form a double loop. The needle 1n descending will pass through this loop of slack and form an additional loop on the looper side of the fabric which the looper Will cut when entering the loop below the fabric and it is therefore impossible to make a continuous stitch. In other words, an article sewed when this happens instead of having a continuous stitch will be held. together by a number of short sewed port1ons with spaces in between them which are not sewed due to the fact that the needle thread has been cut by the looper. This makes 1t necessary to reject the work and if the material is to be saved, the entire stitching will have to be ripped and picked out and the entire work resewed.

It'will be observed from the foregoing dev scription that the thread lock, the loop on the needle bar lever and the loop on the needle bar, the tension on the needle bar, the vertically adjustable member carried by the arm 26 and the looper thread take-up cam co-act and are necessary in forming the stitch illustrated and described. The thread lock operates intermittently to increase the tension on the thread, but does not lock the thread entirely against movement. This is necessary to seat the loop of needle thread firmly around the looper thread in the formed stitch without breaking the needle thread. Were this intermittent tension not present the needle thread could not be drawn up tightly by means of the vertically adjustable member 88 and the loop 82.

The loop 81 carried by the needle bar lever also serves the purpose of retaining the thread wit-hin the thread lock. Tere this loop not present the tendency of the loop 82 would be to cause the thread to jump out of the thread lock due to the rapid up anddown movement of the needle bar.

The loop in the upper end of the needle bar and the vertically adjustable member carried by the arm 26 act as previously pointed out to draw up the needle thread. This action takes place when the needle has almost completed its downward stroke and while the needle thread is under the additional tension imparted to it by means of the intermittent thread lock, thus taking up the slack while the needle is descending.

The thread tension carried by the needle bar also performs the function of a thread support for holding the thread and preventing it from forming a double loop on both sides of the needle. In addition the function of the special form of looper thread take-up caml` besides forming the slack and releasing it, has another drawing-up movement, which acts as a slack take-up for the looper thread and has a tendency to cause it to lie closely to the fabric, instead of being loose between the stitches of needle thread, and it also holds the looper thread under this tension long enough to allow the needle thread to be drawn in and then it is released when the goods are being'fed forward. lVere this not done the looper thread would not feed with the fabric and would be broken.

While I have shown an intermittent lock which is operated by cam surfaces working upon each other, still there are various other types of intermittent lock which may be employed to accomplish my pur ose. The cssential -feature of the intermittent lock being its location at some point between the source of needle thread supply and the needle bar so that the pulling-up or seating of the thread can be accomplished by the needle bar, and without putting any addi'- tional tension on the needle during the pulling-up operation.

Having fully described my invention, what I claim is l. A machine for forming stitches comprising a base having an integrally formed arm, a needle bar reciprocally mounted in said arm, a needle bar operating lever pivotally secured to said arm, means for rocking said needle bar operating lever, a needle thread tension mounted on the arm adjacent the rear end thereof, an intermittent thread lock carried by the arm adjacent the thread tension and operated by the movement of the -ncedle bar operating lever for locking the needle thread at predetermined intervals, a needle thread pull-up carried by the arm and co-acting with the needle bar for drawing the loop of needle thread of the previously formed stitch taut, a needle thread tension carried by the needle bar, a looper. a quick acting looper thread take-up cam carried by the base of the machine, and means for removing the looper thread from the looper thread take-up cam at predetermined positions of the looper.

2. In a machine for forming stitches, a constant tension for the needle thread and looper thread carried thereby, a needle bar lever, a needle bar operated by said lever, a needle thread lock intermittently operated by said needle bar lever and located adjacent the constant tension, a constant tension carried by the needle bar, a needle thread pullup composed of a stationary member carried by the head of a sewing machine and a member carried by the needle bar and adapted to co-operate with said stationary member, a looper, and a looper thread take-up cam for taking up and releasing slack in the looper thread. i

3. In a machine for forming stitches, a base-having an integrally formed a'rm, con- Stan-t tensions for needle and looper threads carried by said arm, a needle bar lever pivf otally carried by said arm, a needle bar mounted in the arm and operated by said lever, a needle thread lock carried by the arm and located in front of said constant tensions and adapted to be intermittently operated by the needle bar lever, a guide loop carried by the needle bar lever interposed between the needle bar and intermittent thread lock, a constant tension carried by the needle bar, a thread pull-up comprising a stationary member carried by the arm, and a member carried by the needle bar, a looper, and a looper thread take-u cam for taking up and releasing slack in t e looper thread.

4. In a machine for forming stitches the combination with an intermittently operating needle thread lock, a needle thread pullup above the lower end of the needle bar,l a needle bar, a needle thread tension carried by the bar, of a looper thread take-up cam adapted to take up and release the slack in the looper thread twice during each revolution of the cam and during the action ot' the needle thread pull-up to exert an additional pull-up on the looper thread.

5. In a machine for forming stitches, the combination with a base having an integrally formed arm, of constant tensions for the needle and looper threads, a needle bar lever, a needle bar, a needle thread lock carried by the arm and located to the rear of the needle bar and operated by the needle bar lever adapted to apply a graduated tension to the needle thread, a guide loop carried by the needle bar lever and interposed between the needle bar and thread lock, a constant tension for the needle thread carried by the needle bar, a needle thread pull-up coacting with the needle bar, a looper, and a looper thread take-up cam adapted to take up and release Slack in the looper thread twice during each revolution of the cam one ot' said take-np movements being augmented just before the release and during the operations of the needle thread pull-up whereby the looper thread is caused to lie snugly along the underside of the fabric being sewed.

(i. In a mach-ine for forming stitches, constant tensions for the needleand looper threads, a needle bar lever, a needle bar, an adjustable needle thread lock composed of a stationary cam and a movable cam adapted to be operated by said needle bar lever and located between the needle bar and constant needle thread tension, a guideA loop carried by the .needle bar lever and interposed between the needle bar and thread lock, a constanttension secured to the needle bar, a needle thread pull-up o erated through the movement of the need e. bar, a looper, a looper thread take-up cam adapted to take up and release slack in the looper thread twice during each revolution of the cam, and means whereby said needle bar, looper, and looper thread take-up cam may be placed in operation simultaneously.

7. In a machine for forming stitches comprising a base having an integrally formed arm, constant regulated tensions for the needle and looper threads carried by said arm, a needle bar, a needle carried by said bar, a lever for operating said bar, a needle thread lock designed to give a graduated tension carried by the arm and located between the constant regulated tension and needle bar, means carried by the lever for intermittently operating said tension, a constant tension carried by the needle bar, means carried by the arm adjacent the needle bar and co-acting with said needle bar for imparting a retrograde movement to a portion of the needle thread between the intermittent tension and needle, a looper, a looper thread take-up cam adapted to take up and release slack in the looper thread, and means for placing said needle bar, looper and looper thread take-up cam in operation simultaneously.

8. A sewing machine comprising in combination with a base having an arm secured there-to, a needle bar lever pivoted to said arm, a. needle bar mounted in said arm, a connection between said needle bar and needle bar lever, a looper, meansfor operating said looperlongitudinally,means for moving said looper laterally, a looper take up Cam for taking up and releasing slack in the looper thread and at predetermined intervals and for predetermined lengths of time, pan tensions carried by thelarm for engaging the needle and looper threads, a

pan tension carried by the needle bar, an intermittent thread lock carried by the arm and operated by the needle bar lever, said intermittent thread lock located between the nee-dle thread pan tension carried by the arm and the needle bar, a needle carried by the needle bar, an adjustable 'member carried by the arm adjacent the needle bar, a loop carried by the upper end of the needle bar, said loop adapted to pass the adjustable member and act as a pull-up on that branch ot needle thread between the needle andintermittent tension, and means for placing the needle har operating lever, the looper and looper thread take-up cam in operation simultaneously.

9. In a sewing machine, the combination with a base having an arm, a needle, a needle bar, a needle bar operating' lever, and pan tensions carried by the arm, Aof an adjustable intermittent thread lock mounted on the arm intermediate the pan tensions and the needle bar and operated by said needle bar lever, and means carried by the arm and needle bar whereby the downward movement of the needle bar imparts a retrograde movement of the needle thread through the needle while the intermittent tension is applied, whereby a completed stitch is drawn up and seated.

10. In a sewing machine, the combination with a base having an arm, a needle bar carried by said arm, a needle carried by said bar, a needle bar operating lever and pan tensions carried by the arm, and a needle thread pull-up, of an adjustable intermittently operating thread lock mounted on the arm intermediate the thread pull-up and the pan tensions and operated by said needle bar lever for holding the needle thread against movement at a predetermined position ot' the needle bar whereby a completed stitch is pulled up and tightlyr seated, and means lor placing the. machine in operation.

11. In a machine for forming stitches the combination with a sewing machine head having` van intermittently operated needle thread lock, a needle and needle bar located in advance thereof, and means for imparting a retrograde movement of the thread through the eye of a needle during the descent of the needle bar and while the intermittent thread lock is applied, ot a looper and a looper thread cam adapted to take up and release slack in the looper thread twice during its rotation, said cam being provided with a projection for imparting an additional pull-up on the looperthread and placing it under tension while vthe needle thread is being pulled up.

12. In a machine for forming stitches the combination with a sewing machine head having an intermittently operated needle thread lock, means for regulating the degree ot tension exerted by said thread lock, a needle and needle bar located in advance thereof, and means for imparting aV retrograde movement of the thread through the eye ot' a needle during the descent ol the needle bar and while the intermittent thread lock is applied, of a looper and a looper thread cam adapted to take up and release slack in the looper thread twice during its rotation, said cam being provided with a projection for imparting an additional pull-up on the looper thread and placing it under tension while the needle thread is being pulled up.

13. In a machine for forming stitches the combination with a sewing machine head provided with an intermittently operated needle thread lock, a needle and needle bar located in advance thereof, and adjustable means for imparting a predetermined amount of retrograde movement ot the thread through the eye of a needle during the descent ot the needle bar and while the intermittent thread lock is applied, o't a looper and a looper thread cam adapted to take up and release slack in the looper thread twice during its rotation, said cam provided with a projection for imparting an additional take-up to -the looper thread thereby placing it under tension while the needle thread is being pulled up.

14. In a machine for forming stitches the combination with a base having an arm provided with an intermittently operated needle thread lock, means for adjusting said thread lock so as to accommodate various sizes of thread, a needle and needle bar located in advance thereof, and adjustable means for iinpaiting a retrogi'ade movement of the4 thread through the eye of a needle during the descent of the needle bar and while the intermittent thread lock is applied, of a loop er and a looper thread cam adapted to take up and release slack in the looper thread twice during its rotation, said cam being provided with a projection for imparting an additional take-up to the looper thread and placing it under tension while the needle thread is being pulled up whereby the looper thread is caused to not lie snugly against the work.

.15. In a sewinfr machine, a thread lock, means for operating the thread lock intermittently, means for supplying needle thread under tension to the thread lock, a needle bar, a needle carried by the bar, means for operating said needle bar, means co-acting with the needle bar for producing a retrograde movement of the needle thread through the eye of the needle, a looper and looper cam, means for operating the same, means t'or supplying looper' thread under tension to the looper, said looper cam being arranged to produce and take up slack in the looper thread twice during each cycle of the needle bar.

16. In a sewing machine, a thread lock, means for operating the thread lock intermittently, means for supplying needle thread under tension tothe thread lock, a needle bai', a needle cairied by said bar, means for operating said needle bar, means col-acting with the needle bar for producing a retrograde movement of the needle thread through the eye of the needle, a looper and looper cani, means for operating the same, means for supplying looper thread under tension to the looper, said looper cam being substantially oblong whereby slack is produced and taken up in theA looper thread twice during each cycle of the needle.

17. In a sewing machine, a thread lock, means for operating said thread lock intermittently, means for supplying needle thread to the thread lock, a needle bar, a needle carried by said bar, and stationary means co-acting with the needle bar for producing a retrograde movement of the needle thread through the eye ot the needle.

18. In a sewing machine` a thread lock, means for supplying thread to said thread Iock, means for operating said thread lock intermittently, a needle and needle bar, means for operating said needle bar, and means co-actlng with the needle'bar during its descent for producing a retrograde movement of the needle thread through the eye of the needle whereby a. tightly drawn stitch is formed.

19. In a sewing machine, an intermit- 10 tently operated thread lock, means for sup# plying thread to said lock, a needle and needle bar, and means whereby the needle bar during predetermined portions of its movement will impart a retrograde m0vement t0 the needle thread through the eye of the needle and between the needle and the thread lock.

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

DANIEL BELCHER.

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