US3068818A - Two-thread chainstitch sewing machine - Google Patents

Description

Dec. 18, 1962 E. SCHOIJ ETAL TWO-THREAD CHAINSTITCH SEWING MACHINE 7 Sheets-Sheet 1 Filed Dec. 6, 1960 Dec- 13,1952 E. scHoLJ ETAL 3,068,818

TWO-THREAD CHAINSTITCH SEWING MACHINE Filed Dec. 6, 1960 7 sheets-sheet 2 61 III E. SCHOIJ ETAL TWO-THREAD CHAINSTITCH SEWING MACHINE Dec. 18, 1962 '7 Sheets-Sheet 3 Filed Dec. 6, 1960 FIG.6

FIG. 5

Dec. 18, 1962 E. SCHOIJ ETAL TWO-THREAD CI-lAINSTI'I'CI-I SEWING MACHINE '7 Sheets-Sheet 5 Filed Dec. 6, 1960 Dec. 18, 1962 E. SCHOIJ ETAL TWO-THREAD CHAINSTITCH SEWING MACHINE 7 Sheets-Sheet 6 Filed Dec. 6, 1960 Tv A:

Dec. 18, 1962 E. SCHOIJ ETAL 8,068,818

TWO-THREAD CHAINSTITCH SEWING MACHINE Filed Dec. 6, 1960 7 Sheets-Sheet 7 99 (b) mg "2 Patented Dec. 18, 1962 3,068,818 T NG-THREAD CHAINSTITCH SEWING MACHINE Edgar Schoij and Clarence (3. Smith, Chicago, Iil., as-

signors to Union Special Machine Company, Chicago,

1th, a corporation of Illinois Filed Dec. 6, 1960, Ser. No. 74,192 13 Claims. (Cl. 112200) This invention relates to two-threaded chainstitch sewing machines and more particularly to improved devices for handling the threads in such machines to insure proper stitch formation and to enable proper chaining off of a line of stitching after the Work passes beyond the stitching point.

The invention is applicable to plain two-thread chainstitch machines adapted to form a single straight line of two-thread chainstitching and it is also, and particularly, applicable to two-thread chainstitch machines of the type adapted to form a zigzag line of stitching. Furthermore, the invention is applicable to machines embodying a plurality of needles and a single looper for producing a line of chain stitches, as well as to machines provided with a plurality of needles and a plurality of loopers for the simultaneous formation of two or more lines of twothread chainstitches.

A special advantage of the invention is its adaptability to provide perfect stitching even in the course of a tacking operation in which the work is shifted by the operator in various directions to lock the end of a scam in place. Two-thread chainstitch machines as heretofore constructed have occasioned considerable difficulty in performing the desired tacking operation without the skipping of stitches or other improper formation of the desired seam.

With the foregoing purposes in view the invention provides a novel spreader adapted to cooperate with the needle thread and the looper thread to open out an appropriate triangle for the entry of the needle on its next downward stroke. The spreader provided for this purpose is of simple construction, capable of high speed operation and it is given a four-motion movement parallel with and slightly below the work supporting surface. The construction is such as to insure accurate and uniform movement of the spreader member through its cycle at high speeds. For this purpose the spreader comprises an elongated arm or bar having a hooked formation at its active end adapted to cooperate with the stitch forming threads, this bar being bodily slidable Within a swivel member which is adapted to turn and thus impart movement to the hook in a direction transverse to the longitudinal axis of the bar. To impart the described four-motion movement to the spreader hook a single drive connection from the main shaft of the machine is provided, this involving an eccentric secured to a vertically disposed shaft and arranged to impart to the spreader bar both its longitudinal reciprocatory movements and its turning movements about the axis of the swivel member mentioned.

A further feature of the invention, which facilitates the handling of the work in the course of a tackling operation and also insures proper chaining off of the stitch forming threads, involves the provision of a special presser foot construction. The latter is such that in the normal operation of the machine the presser foot is urged against the work and retains the latter against the throat plate or the feed dog with a desirable spring force during a normal stitching operation. It is so constructed, however, that the normal spring force may readily be removed from the presser bar by the operator through a knee press or the like, while a comparatively light force is applied along the line of stitch formation by sepaarte spring means incorporated in the presser foot. This greatly facilitates tacking of the end of a line of stitching. Also the special spring element, during normal operation of the machine, applies a lighter force to the line of stitching as this is being incorporated in the work and to the thread chain that is formed after the work passes beoynd the point of stitch formation.

With the foregoing objects, features and advantages of the invention in view, certain preferred embodiments of the same will now be described in detail in connection with the accompanying drawings, in which:

FIG. 1 is a vertical sectional view through the frame of the zigzag sewing machine embodying the invention;

FIG. 2 is a view partly in end elevation and partly in vertical section through the machine shown in FIG. 1, with a cover plate removed from the head of the frame;

FIG. 3 is a transverse vertical section through the machine taken along the line 33 of FIG. 1;

FIG. 4 is a detail view in vertical section showing the means for imparting needle avoid movements to the looper;

FIG. 5 is a side elevational view of a throat plate embodied in the machine;

FIG. 6 is a plan view of the throat plate;

FIG. 7 is a perspective view of a member connected with the spreader bar of the machine;

FIG. 8 is an end elevational view of the throat plate;

FIG. 9 is a plan view of the base portion of the machine with the cloth plate removed, a portion of the frame and certain parts being shown in horizontal section;

FIG. 10 is a perspective view showing the cooperation of two needles, a single looper and a spreader hook and a form of seam produced thereby;

FIG. 11 is a perspective view showing the cooperation between a pair of needles, a pair of loopers and a pair of spreader hooks adapted to form the type of scam illustrated therein;

FIG. 12 is a plan view of a presser foot and its shank alcllapted for use on a plain, two-thread chainstitch mac me;

FIG. 13 is a bottom view of the presser foot and shank shown in FIG. 12;

FIG. 14 is a vertical sectional view through the presser foot and shank of FIG. 12;

FIG. 15 is a plan view of a presser foot and shank adapted for use on a zigzag sewing machine arranged to form a two-thread chainstitch zigzag seam;

FIG. 16 is a bottom view of the presser foot and shank shown in FIG. 15;

FIG. 17 is a vertical section through the presser foot and shank of FIG. 15;

FIG. 18 is an elevational view of a presser foot and shank of a slightly modified construction;

FIG. 19 is a perspective view of a bracket for carrying a swivel for the spreader 'bar of the machine;

FIG. 20 is a perspective View of a cooperating swivel member;

FIG. 21 is a perspective view showing the cooperation between the needle, looper and spreader hook in the formation of a two-thread zigzag chainstitch as the work is being moved forwardly by the operator in the course of tacking;

FIGS. 22 through 27 are views similar to FIG. 21 but showing the parts in different positions assumed in the course of stitch formation; and

FIG. 28 is a plan view showing the spreader mechanism in relation to the looper and needle at five different points in a cycle of operation of the machine.

The invention has been primarily illustrated in its application to a zigzag sewing machine of the type disclosed in the patent to Hayes, et al., No. 2,792,797, granted May 21, 1957. Reference may be had to said patent for certain details of the construction of the machine which are not so fully illustrated in the present drawings.

Referring now to the drawings, the machine comprises a frame having a base portion 10, a vertical standard 11 at one end of the base portion, an overhanging arm pro jecting from the vertical standard over the base portion and terminating in a head 13. A main drive shaft 14 is provided in the base of the frame, this shaft preferably being formed in several sections interconnected by suitable couplings for simplicity of construction and assembly. At its right end the shaft 14 extends outwardly of the frame of the machine and carries a combined handwheel and pulley 15 through which the shaft may be turned by hand for adjustment purposes and by a belt connected with a suitable power source, such as an electric transmitter, for normal operation of the machine.

The stitch forming devices of the machine include a reciprocatory needle 16 carried by a needle bar 17 arranged for'reciprocation in suitable bearings provided in an arm 18 of an L-shaped member pivoted at 19 in the head of the overhanging arm. A horizontally extending arm 20 of the L-shaped member carries a ball pin 21 at its right end (FIG. 1) which cooperates with a strap at the upper end of a pitrnan 22. At its lower end, pitrnan 22 has anotherstrap cooperatingwith a ball pin 23 carried by a rock member 24 arranged to rock about the axis of a supporting pin 25 mounted in bracket plates 26 secured to the vertical standard of the frame. A shaft 27 journaled in the bracket plates 26 carries a gear 28 which meshes with a pinion 29 secured to the main drive shaft 14. -.The gear 28 and pinion are adapted to rotate the shaft27 at half the angular speed of the shaft 14. As shown in said Hayes et al. patent, a cam carried by the shaft 27 cooperates with a forked downward extension of rock member 24 and causes the latter to rock through a certain angle first in one direction and then in the other as the shaft 27 is rotated. Such rocking of member 24 serves to rock the L-shaped member 18, 20 about the pivot 19 and thus serves to shift slightly the path of reciprocation of the needle bar 17, thus serving to form a zigzag line of stitching. It will be understood that on one revolution of the shaft 14 the needle bar. 17 will be reciprocated along one path and during the next revolution of the shaft 14 the needle bar will be reciprocated along a slightly different path.

For reciprocating the needle bar there is provided a crank 30 on the shaft 14 which cooperates with a strap at the lower end of a pitrnan 31, the upper end of which carries a strap cooperating with a ball pin extending toward the right from the end of a lever 32 mounted for rocking movement about the axis of a shaft 33 extending transversely of the overhanging arm. At the opposite end of the lever 32 there is pivotally connected a link 34 the opposite end of which is pivotally connected with a block 35 secured to the needle bar 17.

Cooperating with the needle in the formation of twothread chainstitches is a looper 36 secured to the upper end of an arm 37 pivotally connected by a screw stud 38 to a lateral extension 39a of a sleeve 39 secured to a rock shaft 40. LAS best shown in FIG. 4, the shaft 40 has secured thereto an arm 41 having its outer end pivotally connected with the lower end of a pitrnan 42 having a strap cooperating with an eccentric 43 secured to the shaftv 14. -Anti-friction bearing means is preferably provided between the eccentric 43 and the inner surface of the strap formed at the upper end of pitrnan 42. Rocking of the shaft 40, through the connections described, serves to impart needle avoid movements to the looper 36. Loop seizing and shedding movements are imparted to the latter through a connecting rod 44 having a split bearing portion 45 cooperating with a ball pin 46 extending laterally from the arm 37. At its opposite end the connecting rod has a split bearing 47 which cooperates with a ball pin 48 extending laterally from an arm 49 secured to the rock shaft 50. The latter has an arm '51,'within an enclosed portion of the base of'the machine, provided at its end with a ball pin cooperating with a strap at the lower end of a pitrnan 52. The upper end of this pitrnan has a strap cooperating with a spherical crank 53 provided on the shaft 14.

For advancing the work in the course of stitch formation a feed dog 54 (FIG. 2) is secured by a screw 55 to the upper end of a feed bar 56 having its left end pivotally connected with a feed rocker 57. This feed rocker is secured to a rock shaft 58 journaled in spaced lugs provided in the base of the frame. At an intermediate point the feed rocker 57 carries a laterally extending pin 59 upon which is clamped an arm 60 (FIG. 9). The forward end of this arm is pivotally connected with the lower end of a pitrnan 61 (FIG. 1) which cooperates with an adjustable eccentric 62 carried by the main drive shaft 14. Through these connections, feed and return movements are imparted to the feed dog. Extending downwardly from the feed bar 56 is an arm 63 which is pivotally connected to the lower end'of a pitrnan 64 having a strap portion cooperating with an eccentric 65 secured to the shaft 14. Preferably, as shown, anti-friction-bearing means is provided between the eccentric 65 and the surrounding strap. Lifting and lowering movements are imparted to the feed dog by the eccentric 65.

Cooperating with the feed dog to retain the work'inv engagement therewith is a presser foot 66 which is pivotally connected by a pin 67 with a shank 68 secured to the lower end of a presser bar 69. The latter is mounted for vertical movement within a bearing sleeve 70 carried by the head of the overhanging arm. Within such head there is secured to the presser bar a collar 71 which is engaged by the lower end of a spring 72. The upper end of the latter surrounds a pin extending downwardly from a threaded member 73 having threaded engagement with an opening the top of the head of the overhanging arm. A knurled member 74 permits turning of the member 73 to lift or lower the same and thus vary the force appliedby the spring 72 to the presser bar 69. Suitable connections are provided from a knee press or the like to the presser bar for lifting it against the action of the spring 72. This may be used to lift the presser foot completely away from the work or it may be used to overcome all, or the major part, of the force of spring 72 and thus permit the operator to shift the work freely in the region of stitch formation for tacking the ends of a seam. The lifting mechanism mentioned comprises a pin 75 extending laterally from the collar 71 and cooperating with a link 76 extending downwardly from the end of a lever 77 (FIGS. 1 and 2). Thethicknesses of Work are encountered. Lever 77 is of hell crank construction and has a vertically extending arm 78.

which is connected by a rod 79 with a plate 81 secured to a rock shaft 82 within the vertical standard of the machine..

A spring normally urges the lever 77 in a counterclockwise direction (FIG. 1). When it is desired to lift the presser foot in the manner explained, the shaft 82 may be rocked by any suitable connection with a knee press or the like. As shown in FIG. 2, the shaft 82 may carry an arm 83, outwardly of the rear face of the vertical standard, which is adapted for connection with a knee press member in a well known manner.

' When the feed dog is below the work supporting surface of the machine the presser foot will he urged by the spring 72 into engagement with a throat plate 84 fitted into a suitable opening in the cloth plate 84:! at the top of the base portion of the machine. The form of the throat plate is illustrated in FIGS. 5, 6 and 8. It is provided with openings 85 through which the feed dog may be urged upwardly into engagement with the work and foot for use in connection with a plain, two-thread chainstitch machine. Its work engaging portion 66 has a recess in its bottom face adapted to receive a flat spring member 87 having overturned ends 37a adapted to ride upon the top of the member 66. Springs 8% fitted into recesses in the lower end of the shank 63 of the presser foot engage the upper surface of the member 87 and urge this downwardly into the position shown in FIG. 14. It will be appreciated that the work engaging surface of member 66 cooperating with either the feed dog or the throat plate will take the main force of the spring 72, while the spring plate 87 will be urged downwardly only under the force of the springs 88 into engagement with the line of seam formation or the thread chain formed between the pieces of work. Also it will be appreciated that if the knee press member mentioned is operated to urge the presser bar upwardly against the action of the spring 72, without any appreciable lifting of the presser bar, the work will be retained against the throat plate or the feed dog only by the action of the spring plate 87 under the force of the springs 88. This greatly facilitates the movement of the work by the operator in performing a desired tacking operation. The presser foot is provided with an opening 89 through which the upwardly bent forward portion of the spring plate 87 passes and through which the needle passes in the course of stitch formation. If desired, an opening or slot 90 may extend forwardly from the opening 89 to the free end of the upwardly turned portion of the presser foot. Spring plate 87 is so mounted as to be free to tilt slightly about both its longitudinal and transverse axes in relation to the portion 66.

FIGS. 15, 16 and 17 illustrate a modified form of presser foot particularly adapted for use on zigzag sewing machines. It differs from the presser foot shown in FIGS. 12, 13 and 14 simply in the contour of the main work engaging portion 91. This has parallel side edges and is provided with a V-shaped opening 92 extending from the forward end of part 91 into the needle opening 92a. There is thus provided upwardly extending portions 93 which are more suitably spaced for use in connection with a zigzag machine.

In FIG. 18 there is shown another modification in which a work engaging member 94 is pivotally connected with the shank 68 by a pin 95. Only one spring 96 is provided, just in rear of the pivot pin 95, to engage the spring plate 87 and urge the latter downwardly. In this construction the forward end of the presser foot may be solid and not provided with a slot of the character shown at 91 in FIG. 12.

Turning now to the novel spreader mechanism incorporated in the machine to insure proper formation of stitches under all conditions, including tacking operations, the general arrangement of the parts is shown in FIG. 9. The spreader mechanism includes a spreader bar 97 carrying a hook 98 at its free end in the region of stitch formation. 'Bar 97 is mounted for sliding and turning movement in a swivel member 99 carried by a bracket 100 which is secured by screws 191 to a portion of the frame. As shown in FIG. 1, the spreader bar extends substantitally horizontally a slight distance below the cloth plate 84a of the machine. The details of the swivel member 99 and its supporting bracket 101 are shown in FIGS. 19 and 20. Screws 191 which serve to retain the bracket 100 on the frame cooperate with openings 102 in the bracket and are threaded into openings in the frame. Openings 102 are slightly elongated and are slightly wider than the diameter of the shanks of screws 101. This arrangement permits ready adjustment of position of the bracket on the frame to locate the swivel axis in the desired position. Swivel member 99 is inserted from the bottom through an opening 103 in the bracket 1%. Upwardly extending flange segments 1134 provide spaced shelves 105 on the upper surfaces of which the bar 97 is slidable. Member 99 has a radimly extending flange 19-5 at its lower end which cooperates with the under-surface of the bracket 100. The

flange and the main body of member 99 are provided with a passage 107 through which the bar 97 may slide. It will be seen that the member 99 is held in place on the bracket by the bar 97 and the latter is free to turn the member 99 about its axis in the course of longitudinal sliding movement of the bar. Such turning of the swivel member is permitted by the shoulders provided at the ends of the segmental flanges 1% in the region of the supporting surfaces 105.

The right end of the bar 97 (FIG. 9) has secured to it a member 168, which is shown in inverted position in FIG. 7. Screws 109 passing through elongated openings 11% in the member 108 are threaded into the bar 9'7 to retain the parts in assembled relation. Gpenings 116 permit a. slight longitudinal adjustment of the bar 97 in relation to member 193. Member 108 has a cylindrical portion 111 which cooperates with a screw stud 112 eccentrically disposed on a disc 113 secured to the upper end of a shaft 114 (FIG. 3). As shown in FIG. 7, roller bearing elements are preferably provided between portion 111 and the stud 112. Secured to the shaft 114 at an intermediate point is a spiral or helical gear 115 which meshes with a spiral or helical gear 116 secured to the main drive shaft 14. This arrangement is such that upon each revolution of the shaft 14 a single revolution will be imparted to the shaft 114. Rotation of the latter imparts longitudinal and swinging movements to the bar 97.

In FIG. 28 the relative positions of the looper and the spreader bar with its hook are indicated at different points in a cycle of the machine. The path of the needle is also indicated by the cross marks in the different views of said figure. It may be mentioned that in the bottom view the two different paths of the needle of a zigzag sewing machine are indicated by the two cross marks.

In the top view of FIG. 28, showing position (a), the needle 16 is at the lowermost position of its stroke while the looper is substantially at its rightmost position and is ready to be returned toward the left. t will be noted that the book 98 of the spreader is at this time in rear of the path of the needle and of the blade of the looper. In position (b) the needle is in the middle of its upward stroke and the looper has entered and seized the needle thread loop. By this time the hook 93 has been shifted forwardly into a position in front of the needle and the looper so that it is ready to seize the looper thread extending from the work down to the point of the looper and is also ready to seize the two legs of the needle thread loop. At position (c) the needle bar is in the uppermost position of its stroke and the looper is in its leftmost position and ready to be returned toward the right. It will be noted that at this time the hook of the spreader has engaged the leg of the looper thread and the two legs of the needle thread loop mentioned above and has shifted these toward the right of the path of the needle. In position ((3) the needle bar is in the middle of its down stroke and the looper has been shifted forwardly in its needle avoid movement and has also been shifted some distance toward the right. It will be noted that a triangle has been formed between the blade of the looper, the leg of the looper thread and the two legs of the needle hread. One leg of the needle thread is shown as extending from the last travel of the needle through the work and the cross mark indicates the path of the new downward movement of the needle in a zigzag sewing machine. At position (e) the needle is entering the thread triangle in one or the other of the two positions indicated by the cross marks while the thread triangle mentioned above is still opened out. The looper is moving toward the right into the (a) position. The same cycle is repeated throughout a seam forming operation.

In FIGS. 2227, inclusive, there is shown in perspective the relationship between the work, the needle, the looper and the spreader hook 98 at diiferent points in a cycle of operation of a zigzag, two-thread, chainstitch sewing machine. These views illustrate somewhat more clearly the relationship of the various threads in the course of normal zigzag stitch formation. The looper at this time is at its extreme leftmost position and its forward, needle avoid position and is about to be shifted toward the right. The hook 98 at this time is holding the leg of looper thread extending from the work to the looper and the two legs of the needle thread extending from the needle downwardly around the looper and up to the work. FIG. 26 shows the needle entering the triangle so formed between the looper blade and the various thread legs being retained by the hook 98. In FIG. 27 the needle is shown in its lowermost position, in which it is about to retain the end of a loop of looper thread while the previously seized needle thread loop is about to be released. 7 The spreader hook 98 at this time is being shifted toward the left to release the various threads which it has previously picked up and held. From the FIG. 27 position the looper continues to move toward the right into the position shown in FIG. 22 and is given its needle avoid movement toward the rear. Hook 98 is also restored to its FIG. 22 position, and the needle is about to rise along its right-hand path of movement. The cycle is thus ready to be repeated, with the change of the path of the needle reversed. FIG. 22 shows the looper in its rightmost position and having been given its needle avoid movement in the direction of feed, the needle being about to rise from its lowermost position. At this time the hook 98 is being given its transverse swinging movement toward the front of the machine in readiness for seizing the various thread legs in the manner described. In FIG. 23 the looper is moving toward the left and is about to seize the loop of needle thread extending from the eye of the needle up to the work. FIG. 24 shows the looper continuing its movement toward the left while the needle is moving upwardly and the spreader hook is moving toward the right to carry the various thread legs into the position shown in FIG. 25. FIG. 25 shows the needle at about its uppermost position and ready to descend into the work.

FIG. 21 is similar to the figures just described but shows the various parts in the position in which the needle is about to enter the triangle formed between the leg of looper thread and the two legs of the seized needle thread, and it shows how the triangle is properly formed even though the work itself is at this time being moved forwardly by the operator in the course of penforming a tacking operation.

As has been stated, the invention may also be used advantageously in connection with a sewing machine adapted to form a single line of plain two-thread chainstitches. For this purpose the needle bar may simply be mounted for reciprocation in fixed bearing sleeves mounted in the head of the overhanging arm, and the rockable member for shifting the path of the needle upon successive cycles to form a zigzag line of stitching may be eliminated. The cooperation of the needle, the looper and the spreader member with its hook 98 may be as above described in relation to FIGS. 21 through 28, inclusive. It will be apparent that the spreader hook will function to open up a triangle for the entry of the needle more simply and more readily for such a machine than for a zigzag type machine.

In FIG. there is illustrated the application of the spreader mechanism to a two-needle, single-looper machine. The needles 16a and 16b are mounted on the needle bar with their axes in the same plane transverse to the line of feed or line of stitch formation. A looper 36a of the 4-motion type may be operated in the same manner as the looper 36 of the zigzig machine above described. This looper will seize the needle thread loops from both of the needles, and then prior to the next descent of the needle bar the spreader hook 98 will be given the turning movement toward the front of the machine and then a movement toward the left, followed by the needle avoid movement of the looper, thus opening up a triangle between the'looper thread 117 and the two loops of needle thread 118 and 119. This insures the proper entry of the needles 16a and 16b through the triangle thus formed, as the points of the needles descend below the work.

FIG. 11 shows the relationship between a pair of needles, a pair of loopers and a pair of spreader hooks for the formation of two separate lines of plain, twothread chainstitches. Thus, a pair of needles 16c and 16d may be mounted on the needle bar with their axes in a vertical plane disposed diagonally to the line of feed or line of stitch formation. Needle is somewhat in advance and to the left of the needle 16d. Two loopers 36b and 366 are mounted on the looper carrying arm in positions to cooperate, respectively, with the needles 16c and 16d. In this construction the spreader bar will be provided with two hooks 98b and 980, the first serving to pick up and spread the thread of needle 16c and looper 36b to form the desired triangle. Similarly, hook 98c will pick up and spread the thread of the looper 36c and needle 16d to form the desired triangle. Thus,

upon successive operations of the needle bar, the needle.

160 will enter the triangle formed by the hook 98b while the needle 16d will enter the triangle formed by the hook 980.

It will be understood that in the construction of FIGS.

10 and 11 the spreader hooks willbe carried by spreader bars similar to the bar 97 of FIG. 9 and these bars will be given the reciprocatory and turning movements described above in connection with the bar 97.

While several embodiments of the invention have been described in considerable detail it will be understood that various modifications maybe made in the construction and mode of operation of certain of the devices, without departing from the general principles of the invention and within the scope of the appended claims.

What is claimed is: 1. In a chainstitch sewing machine having a main drive shaft, stitch forming members comprising at least one reciprocatory thread carrying needle,

thread carrying reciprocatory looper, and connections from Said drive shaft for reciprocating said stitch forming members, a spreader comprising a reciprocatory bar, a hook carried by said bar adapted to seize and shift loops of thread carried by said stitch. forming members, swivel means having relative sliding engagement With said bar to guide the latter in its reciprocatory movements, said swivel means being oscillatable by said bar about a fixed axis to alter the direction of reciprocation of the bar, and connections from said main drive shaft to said bar for substantially continuously reciprocating the latter and simultaneously causing it to turn about the axis of said swivel means as said bar is reciprocated. 2. In a machine of the character set forth in claim 1, said main drive shaft being horizontally disposed, and said connections from said main drive shaft to said bar comprising a vertically disposed shaft driven by said drive shaft and carrying a circular member in eccentric relation to the axis of said vertically disposed shaft, said bar being connected with saidcircular member for re{ ciprocating and oscillating the bar. 3. In a machine of the character set forth in claim 1, connections from said drive shaft to said needle for changing the path of reciprocation of the latter to pro duce zigzag .stitching, said hook of said spreader serving to form a triangle between the looper, the looper thread and the needle thread of suflicient size to permit passage of the needle therethrough regardless of the path of the needle.

4. A sewing machine of the character set forth in claim 1 having a plurality of thread carrying needles and a single looper cooperating therewitlysaid hook or said spreader being adapted to seize and shift the threads of said plurality of needles and of said looper to'form a triangle between said threads and the looper ofsufliat least one cient size for the entry of said plurality of needles therethrough upon the next reciprocation of the needles.

5. A sewing machine of the character set forth in claim 1 in which said looper is a four motion looper, said connections from said drive shaft being adapted to impart four motion movements to said looper, said looper having its loop seizing and shedding reciprocatory movements across the line of stitch formation, said spreader bar extending and being reciprocated longitudinally across the line of stitch formation.

6. A sewing machine of the character set forth in claim 1 having a plurality of thread carrying needles and a plurality of thread carrying loopers, each of said loopers cooperating with one of said needles to form a line of stitching, said longitudinally movable and oscillatable spreader bar having a plurality of hooks each being shiftable transversely of the line of stitch formation by the longitudinal movement of said bar and along the line of stitch formation by oscillation of said bar and being adapted to seize and shift the threads of one of said needles and of one of said loopers to form a triangle between cooperating needle and looper threads and the related looper for the entry of the related needle therethrough upon the next reciprocation of said needle.

7. in a sewing machine of the character set forth in claim 1, said spreader bar being horizontally disposed in a plane just above the top of said looper at the maximum height of the latter, said swivel means being disposed in a fixed position intermediate the ends of said spreader bar, a crank pin, the end of said bar remote from the 1100?; carried thereby being connected with said crank pin, and connections from said drive shaft for rotating said crank pin in a circular, horizontally disposed path.

8. In a sewing machine of the character set forth in claim 7, a bodily adjustable bracket for supporting said swivel means in predetermined positions longitudinally of said spreader bar.

9. In a sewing machine of the character set forth in claim 7, means for adjusting said spreader bar in a direction longitudinally thereof in relation to said crank pin.

10. In a sewing machine of the character set forth in plaim 1, means driven from said drive shaft for advancing the work being stitched, said work advancing means comprising a four motion feed dog and a presser foot, a spring urging said presser foot against the work, a throat plate having openings through which said feed dog is given four motion movements, said presser foot having portions arranged to cooperate with said throat plate and portions arranged to cooperate with said feed dog, said presser foot having a member shiftable in relation thereto and disposed along the line of stitch formation, and spring means of substantially less force than said spring for urging said member downwardly in relation to said presser toot.

11. In a sewing machine of the character set forth in claim 10, means for exerting a lifting force upon said presser foot to overcome the force of the spring acting thereon, said spring means being adapted to continue to urge said member under said lesser force into engagement with the line of stitching when said lifting force is exerted upon said presser foot.

12. In a sewing machine of the character set forth in claim 10, said member of said pressure foot being a flat spring element mounted for limited vertical and tilting movements in relation to the main portion of said presser foot.

13. In a sewing machine of the character set forth in claim 10, a vertically reciprocatory presser bar, a presser foot carrying shank secured to said presser bar, and means for pivotally connecting said presser foot 'with said shank.

References Cited in the tile of this patent UNITED STATES PATENTS 245,997 Corey et al. Aug. 23, 1881 2,389,112 Newton et a1 Nov. 13, 1945 2,439,332 Becker Apr. 6, 1948 2,729,176 Smith Ian. 3, 1956 2,792,797 Hayes et a1 May 21, 1957 2,902,958 Voigt Sept. 8, 1959 2,932,269 Kubar Apr. 12, 1960 FOREIGN PATENTS 483,989 Germany Oct. 17, 1929

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