US3041988A - Ornamental-stitch changing mechanisms in zigzag stitch sewing machine - Google Patents

Description

TosHlo FUJITA 3,041,988 CRNAMENTAL-STIIGH CHANGING MECHANIsNs IN zIGzAG STITCH SEWING MACHINE 4 Sheets-Sheet l July 3, 1962 Filed Aug. 3l, 1959 Jil/fm amvm July 3, 1962 TosHlo FUJITA 3,041,988

ORNAMENTAL-STITCH CHANGING MECHANISMS IN ZIGZAG STITCH SEWING MACHINE Filed Aug. 5l, 1959 4 Sheets-Sheet 2 MIN/(M7 1.9

July 3, 1962 Tosi-no FUJITA 3,041,988

ORNAMENTAL-STITCH CHANGING MECHANISMS IN ZIGZAG STITCH SEWING MACHINE Filed Aug. 51, 1959 4 Sheets-Sheet 5 July 3, 1962 TosHlo FUJITA ORNAMENTAL-STITCH CHANGING MECHANISMS IN ZIGZAG STITCH SEWING MACHINE 4 Sheets-Sheet 4 Filed Aug. 5l, 1959 United States Patent O (BRNAMENTAL-STITCH CHANGING MECHA- NISMS IN ZIGZAG STITCH SEWING MA- CHINE Tosllio Fujita, Moriguehi City, Osaka-fu, Japan, assigner to Sanwa Mishin Seizo Kabushiki Kaisha (Samva Sewing Machine Mfg. C0., Ltd), Fuse City, Japan Filed Aug. 31, 1959, Ser. No. 837,049 Claims priority, application Japan Sept. 12, 1958 6 Claims. (Cl. 112-1S8) The present invention relates to improvements in a zigzag stitch sewing machine which permits zigzag stitch ing by the transverse oscillation of the needle bar, actuated by a master cam which is driven from the main shaft.

More specifically, the present invention has for an object to provide novel mechanisms vfor accomplishing with great simplicity and ease three essential functions, eg., shifting the center line of stitching, adjustment of amplitude and reversing the feed-direction, either singularly or in combination of two or more functions, so that various patterns of decorative stitches can be produced on the material.

Other features and advantages characterized by the present invention are (l) a great convenience which permits all of these functions to be accomplished without the necessity of stopping the machine and (2) an unique regulating `means which permits the center line of stitch ing and the stitch-length to be shifted to any desired degree.

The mechanisms and parts employed to perform the present invention are described in the accompanying drawings and specification.

In the drawings:

FIGURE 1 represents a side elevation, partly in sec* tion, of a zigzag stitch sewing machine containing the stitch-pattern changing mechanism of my invention.

FIGURE 2 represents a top plan view of the sewing mach-ine, corresponding to FIGURE l, with the bracketarm cover removed.

FIGURE 3 represents an enlarged side elevation, showing the arrangements and functional relationship of the center-line shifting cams, cam followers and arm pieces oscillated selectively by a cylindrical cam upon rotation of the latter.

FIGURE 4 represents a top plan view of the mechanism corresponding to FIGURE 3.

FIGURE 5 represents an enlarged side elevation, showing the arrangements and functional relationship of the direction-reversing cam or cam unit being acted upon by a cam follower and a swingable clip means oscillated selectively by a cylindrical cam upon rotation of the latter.

FIGURE 6 represents `a top plan view of a swingable clip means provided for shifting the center line, which is one of three swingable clips embodied in the machine.

FIGURE 7 represents a perspective view, showing the arrangements of three swingable clip means each accommodating a set of assembled cam followers, and the `arm pieces provided for swinging the cam followers upward from the backsides thereof.

FIGURE 8 represents a side elevation of a movabie arm member provided for shifting the center line,

FIGURE 9 represents a cross-sectional view of the parts corresponding to FIGURE 8, as taken along lthe section line 9*-9.

FIGURE 1() represents a perspective view of the parts corresponding to FIGURE 9.

FIGURE 11 represents a side elevation, showing the arrangements and functional relationship of a swingable 3,041,988 Patented July 3, 1962 ice clip means for the amplitude adjusting means and other parts operatively associated therewith.

FIGURE l2 represents a sectional view taken substantially on the line 12-12 of FIG. 1 and showing a portion of the work-feeding mechanism.

FIGURE 13 represents a perspective view showing certain component parts for transmitting the movement of a swingable clip means to a vertical shaft for feeding the work.

All of these drawings illustrate only those means and functions which are essential to improvements provided by my invention and all other component parts of a zigzag stitch sewing machine `which are not related to the present invention are omitted from the drawings. The same numerals in all figures denote the same parts.

Before making a detailed explanation of the essential mechanisms of my invention, mention shall be made of the following facts:

The bracket-arm or frame 1, hollow standard 2 and bed plate 3 are of the same shapes and constructions as those used for any conventional sewing machine and, similarly, all component parts of a sewing machine mounted within such parts, such as main shaft 4, the needle bar 5 connected therewith and the presser bar 6 are of the saine shapes and constructions as those used for any conventional sewing machine.

As shown in FIGS. l and 2, needle bar 5 is mounted for reciprocation on one leg of a bell crank lever 7 which is pivotally mounted at S on the arm or frame 1 and the other leg of the bell crank lever 7 is connected to meehanism for imparting ra lateral oscillating movement to the needle bar 5.

A plurality of assembled plate cams are mounted on a shaft 12 carrying a mas-ter cam 11 and a worm wheel 16 fixed to the shaft 12 meshes with a worm 9 provided on the main shaft 4, to drive the shaft 12 and cams mounted thereon. As shown, three units of assembled cams, eg., the centerline shifting cams 13, the amplitude adjusting cams 13 and the feed-direction reversing cams 13 each comprising an optional number of cams, are mounted on the shaft 12.

At locations opposite the cam units 13, 13' and 13" clip members 16, 17 and 18 are pivotally mounted adjacent one end for independent pivotal movement on a common shaft `15 carried by the larm or frame l1. The opposite ends of clip members 16, 17 and 1S are operatively connected to links or connecting rods 19, 2t) and 21 respectively.

Three sets of cam followers 22, 23 and 24 are provided and the number of `followers in each set corresponds to the number of cams in the associated cam units. Cam followers 22, 23 and 24 are in the form of bell crank levers one end of which are adapted to engage the respective cams of the cam units, the opposite ends being mounted `for independent pivot-al movement on shafts 2S carried by the clips 16, 17 and 18 intermediate the ends thereof. Three groups of cam follower positioning members 27, 23 and 29 in the form of bell crank levers are mounted adjacent one end for independent pivotal movement on a common shaft 26 carried by the frame of the machine. The opposite ends of the positioning mem bers 27, 28 and 29 are adapted to engage the rear surfaces of the respective cam followers 22, 23 and 24 intermediate the ends thereof.

Each of the cam follower positioning members is provided with a lug 30 constituting a follower engaging a cylindrical cam 31 cairied by a shaft rotatably mounted on the hollow standard 2. The cam 31 is provided with a cam track for each follower positioning member and each track is provided with `one or more lobes 32 for engaging the lugs 30 on the cam follower positioning members. The lobes 32 are so located as to engage and move the associated follower positioning members, either singly or two or more simultaneously. A dial 33 is fixed to the shaft carrying the cam 31 and the dial 33 may be manually adjusted to actuate the cam `follower positioning members 27, 2S and 29 to position the 0am followers 22, 23 and 24 for engagement with the appropriate cams of the cam units 13, 13 and 13 to provide the desired stitch pattern in the manner to be later described.

Heretofore, in a zigbag stitch sewing machine of a conventional type the number of available stitch patterns were limited by the number of cams provided on the cam shaft, and, furthermore, the interchanging of cam members was inconvenient that it was necessary to stop the machine while performing this operation. Even in the case of a zigzag stitch sewing machine in which several cams were provided it was necessary to stop the machine while manually moving a cam follower into engagement with the :desired cam.

In accordance with the present invention it is not necessary to stop the machine when changing stitch patterns, since it is only necessary to set the dial 33 for the desired pattern which results in `bringing the necessary cam or cams and follower or followers into operation thereby providing an almost infinite variety available stitch patterns.

When the dial 33 is rotated and set for the desired stitch pattern, a lug on one or more of the cam follower positioning members engages one or more lobes 32 on the cam 31 which operates to move the follower positioning member or members into engagement with the corresponding follower or followers to move the same into operative engagement Awith the corresponding cam or cams. The motion of the selected cam or cams is transmitted to the corresponding swingable clip or clips by means of the cam follower secured to the latter, so as to impart a swinging motion to the swingable clip. The swinging motion of the said swingable clip or clips is further transmitted, by the linking members 19, 2t) and 21 connected therewith, to a center-line shifting mech- -anism, the amplitude adjusting means or the feed-direction reversing mechanism as desired.

Each of the pivotally mounted clips 16, 17 and 13 is actuated by the selectively operable cam followers 22, 23 and 24 to provide the desired stitch pattern and the relationship between the swingable clip 16 for center-line shifting and the center-line shifting mechanism connected therewith will now be described.

The swingable clip 16 is connected with an oscillatable member 39 through a link 19, a lever 38 and a pintle 38. The said oscillatable member 39 is rigidly secured adjacent the lower end to one end of a pintle 38 rotatably supported in a horizontally-disposed bracket 47 protruding inwardly from the frame wall. A longitudinal groove 4t) is provided in the oscillatable member 39 extending from the top to the bottom.

Opposite the oscillatable member 39, a bifurcated lever 37 is pivotally mounted on a pintle 34. The `arms of the lever 37 provide an opening 41 therebetween and the lever 37 is biased by a spring 42 to move in one direction.

A pintle 36 is fixed to one arm of the bifurcated level 37 adjacent the master cam 11 and pivotally mounted on the pintle 36 is a needle bar oscillating member 35. The member is in the form of an elongated block and adjacent the lower end thereof, there is fixed a projecting pin which provides a cam follower engaging the master cam 11 and rotation of the master cam 11 serves to oscillate the member 35.

A control lever 43 is pivotally and slidably mounted at one end on the frame of the machine and on the opposite end is provided with a pin 44 projecting from opposite sides of the lever 43. One end of the pin 44 is received in the groove 40 of member 39 `and the opposite end of pin 44 is disposed in the space 41 between the arms of bifurcated lever 37.

Since the control lever 43 is further connected with one end of a link member 76 mounted at its base end on a shaft 75, when the shaft 75 is rotated by turning a knob, not shown, fixed to lthe exterior end thereof, the member 76 and the control lever 43 connected thereto are caused to swing, thereby shifting the position of the pin 44 of the control lever 43 within the groove 40 and the space 41 of the member 39 and the bifurcated lever 37 respectively.

In the operation of this portion of the apparatus and upon movement of the clip 16 `by the selected cam 13 and cam follower 23, such movement is transmit-ted through link 19, lever 38' and pintle 38 to oscillatable member 39. Movement of member 39 is transmitted through pin 44 to one arm of the bifurcated lever 37 resulting in movement of the pintle 36 with respect to the master cam 11 thereby varying the mid-point of movement of the needle bar oscillating member 35 resulting from engagement of master cam 11 with cam follower 45 on the member 35. rThis adjustment of the midpoint of movement of member 35 results in adjusting the location of the center line of stitching.

According to the present invention the movement transmitted from the swingable clip 16 for centerline shifting can be adjusted to any desired degree by adjusting the position at which the oscillatable member 39 is connected with the bifurcated lever 37. It is obvious that the amplitude of movement at each part of the oscillatable member 39 will vary as the distance from the center of the pintle 38 to which the oscillatable member is pivotally secured, i.e., lthe further from the center of pintle, the larger the amplitude of movement or the nearer the center of pintle, the smaller the amplitude of movement and at the center lof the pintle the amplitude of movement will be zero. Therefore, if 'the pin 44 provided at the end of the control lever 43 was located on the axis of the pintle 38 by adjusting the control lever 43, the oscillatable member 39 will move in the usual way but the amplitude of movement of the bifurcated lever 37, which is driven from the oscillatable member 39, will be zero. Accordingly, no center line shifting motion will be transmitted to the needle bar.

On the other hand, if the pin 44 was located at the uppermost end of the groove 40, the bifurcated lever 37 will move through maximum amplitude and accordingly the center line of stitching will be shifted to the maximum. Thus, by changing the location of the pin 44 by means of the control lever 43, shifting of the centerline stitching given by the selective interchange of cams 13 and cam followers 22 can be further adjusted, which provides many additional variations in decorative stitch patterns.

The structure and operation of the swingable clip 18 and the stitch length regulating mechanism will now be described.

An operating lever 49 is pivotally mounted at its center on the master cam shaft 12. A link 21 is pivotally secured, at one end 50, to a laterally extending arm 49 on the operating lever 49. An arcuate surface 51 formed with the end 50 of the link 21 as a center, is provided on one side of the swingable clip 18. The link 21 carries, at its approximate midpoint, a roller 52 in such a manner that the roller is always in contact with `the arcuate surface 51, thereby linking the connecting rod 21 with the swingable clip 18. The opposite end portion of the link 21 is extended and connected with the dial 33 by suitable mechanism. Provided at the end 49 of the operating lever 49 is a pin 53, which is engaged with a slot 54 provided in a link 48. This link 48 carries at one end a pin 55, which engages the side of needle bar oscillating member 35 mounted on the bifurcated lever 37. The opposite end 48' of the link 48 is pivotally connected to one arm of a bell crank lever 46, pivotally mounted on the frame of the machine, the other arm of which engages one arm of the bell crank lever 7 to transmit motion thereto.

In accordance with the above described mechanism,

the swinging movement of clip 18 resulting from engagement of one of the cam followers 24 with one of the cams 13 is transmitted to link 21 and operating lever 49 by reason of the engagement of roller 52 with the surface 51 on clip 18. The amplitude of such movement may be varied by adjusting the position of roller 52 with respect to the pivot point 15 of clip 18. Such adjustment may be accomplished through the medium `of dial 33 as described above. The movement of operating lever 49 is transmitted through pin 53 to link 48 which operates to vary the position of cam follower 4S with respect to the pivot point 36 of the needle bar oscillating member 35. Since the movement of needle bar oscillating member 35 resulting from engagement of cam follower 4S with master cam 11 is transmitted to the needle bar 5 through link 4S, bell crank lever 46 and bell crank lever 7, adjustment of the position 55 with respect tothe pivot point 36 of the needle bar `oscillating member 35 will result in varying the amplitude of oscillation of the needle bar S. lt will, therefore, be apparent that Ithe stitch length may be varied, both by selection of any one of the cam followers 24 and by adjusting the position of pin 55 which materially contributes to the wide variation in stitch patterns provided by the apparatus of this invention.

As to the swingable clip 17 for feed-direction reversing,

' it is pivotally secured, `at its lower end portion, to the common shaft 1S as in the case of the other swingable clips 16 and 18. The cam followers 23 whose tips are selectively moved into engagement with the cams 13' for feed-direction reversing are pivotally secured to this swingable clip 17. The swinging movement of the swingable clip 17 actuated by the cam 13' is transmitted to the feeding mechanism through the link and causes the feeding mechanism to reverse feed-direction automatically.

The structure and operation of a means for transmitting the swinging movement of the clip 17 to the feeding mechanism will now be described. Through the medium of the links 2G having one end connected to the swingable clip 17 and carrying at the other end a bifurcated arm member 60, the swinging movement ofthe clip 17 is transmitted to the member 6d to cause pivotal movement, whereupon an arm member 62 fixed to a vertical shaft 61 and having its free end accommodated in the forked head 60 of the member 63 is swung resulting in oscillation of the shaft 61. The motion of the shaft 61 is transmitted to a pintle 64 horizontally disposed under the bed plate 3 by means of a bevel gear 63 fixed to the lower end of the shaft 61 and meshing with a bevel gear 65 fixed to one end of the pintle 64 which operates to rotate a regulator 66 provided at the opposite end of the pintle 64 thereby shifting the operative position of a forked connecting rod 69 connected with the regulator by means of a sliding member 63 slidably received in a groove in the regulator 66. The movement of the forked connecting rod 69 is transmitted to a feed shaft 67 through a link member 74 for automatic reversal of feed direction.

Thus, this automatic feed-direction reversing mechanism, .in conjunction with the center-line shifting mechanisrn and amplitude adjusting means, provides a wide variation of ornamental stitch patterns.

Since the means for driving a feed dog from the feed shaft 67, the means lfor driving a shuttle from a main drive shaft 62 which is in turn driven by a motor 71 provided under the bedplate 3, the means for driving the upper main shaft l from the main shaft "/2 through a belt 73 running over a pulley and the means for swinging the forked connecting rod 69 by means of an eccentric 70 mounted on the main shaft 72 are all of conventional types, a detailed explanation of these means is not considered necessary.

As hereinbefore described, under the present invention when the dial 33 is set for the desired stitch pattern, only the selected operative mechanisms among the various sets of operative mechanisms provided within the machine, are actuated to produce the desired stitch pattern. Thus,

without the trouble of interchanging cam members, stopping the machine in the course of sewing operation, etc. as required in the case of sewing machines of a conventional type, chanveover to the desired stitch pat-tern can easily be effected. Furthermore, such operations as center-line shifting, amplitude adjustment, feed-direction reversing, etc. can be effected with ease and simplicity, either singularly or in combination of two or more of `such operations, which provides various types of decorative stitch patterns.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claims.

Having thus described the nature of my invention, what 1 claim herein is:

l. In a zigzag stitch sewing machine having a hollow frame, a main drive shaft rotatably mounted in said frame, a needle bar mounted in said frame for reciprocating and lateral swinging movements, drive means connecting said shaft and said needle bar for reciprocating the same, a cam shaft rotatably mounted in said frame and driven from said main shaft, a master cam fixed to said cam shaft, a pivotally mounted member engaging said master cam, mechanism operable by said member to impart swinging movements to said needle bar, mid-point adjusting means to vary the location of the pivot point of said member to change the mid-point of said swinging movements, amplitude adjusting means associated with said mechanism to vary the effective lmovement of said member to adjust the amplitude of said swinging movements and means for driving a work feeding means from said shaft and including feed direction reversing mechanism, the combination of three cam units fixed to said cam shaft, each unit comprising a plurality of cams, a clip pivotally mounted on said frame adjacent each cam unit, a plurality of cam followers pivotally mounted on each clip, there being a separate follower for each cam of each unit, means connecting one clip with said midpoint adjusting means, means connecting the second clip with said amplitude adjusting means, means connecting the third clip with said feed direction reversing mechanism, a plurality of cam follower positioning members pivotally mounted on said frame adjacent said cam followers, there being a separate positioning member for each cam follower, each positioning member engaging the associated cam follower, a lug on each positioning member, a cylindrical cam fixed to a shaft rotatably mounted in said frame adjacent said positioning members, a dial on said last named shaft eXteriorly of said frame for facilitating rotation of said cylindrical cam, a plurality of cam tracks on said cylindrical cam, each of said lugs engaging a separate track and one or more lobes on each track, whereby upon setting said dial fora desired stitch pattern, the appropriate lobes on said tracks will engage the associated lugs to move the associated positioning members and thereby move the associated cam followers into operative engagement with the associated cams of said cam units, rotation of said cam units serving to pivotally move said clips in accordance with the contour of the selected cams to adjust the mid-point adjusting means, the amplitude adjusting means land the feed direction reversing mechanism to provide the desired stitch pattern.

2. In a zigzag stitch sewing machine having a hollow frame, a main drive shaft rotatably mounted in said frame, a needle bar mounted in said frame for reciprocating and lateral swinging movements, drive means connecting said shaft and said needle bar for reciprocating the same, a cam shaft rotatably mounted in said frame and driven from said main shaft, a master cam fixed to said cam shaft, `a member engaging said master cam, mechanism operable by said member to impart swinging movements to said needle bar, mid-point adjusting means to vary location of said member to change the mid-point of :said swinging movements, amplitude adjusting means associated with said mechanism to vary the effective movement of said member to adjust the amplitude of said swinging movements and means `for driving a work feeding means from said shaft and including feed direction reversing mechanism, the combination of three cam units fixed to said cam shaft, each unit comprising a plurality of cams, a clip pivotally mounted on said frame adjacent each cam unit, a plurality of cam followers pivotally mounted on each clip, there being a separate follower for each cam of each unit, means connecting one clip with said mid-point adjusting means, means connecting the second clip with said amplitude adjusting means, means connecting the third clip with said feed direction reversing mechanism, a plurality of cam follower positioning members pivotally mounted on said frame adjacent said cam followers, there being a separate positioning member for each cam follower, each positioning member engaging the associated cam follower, a lug on each positioning member, a cylindrical cam fixed to a shaft rotatably mounted in said frame adjacent said positioning members, a dial on said last named shaft exteriorly of said frame for facilitating rotation of said cylindrical cam, a plurality of cam tracks on said cylindrical cam, each of said lugs engaging a separate track and one or more lobes on each track, whereby upon setting said dial for a desired stitch pattern, the appropriate lobes on said tracks will engage the associated lugs to move the associated positioning members and thereby move the associated cam followers into operative engagement with the associated cams of said cam units, rotation of said cam units serving to pivotally move said clips in accordance with the contour of the selected cams to adjust the mid-point adjusting means, the amplitude adjusting means and the feed direction reversing mechanism to provide the desired stitch pattern.

3. ln a zigzag stitch sewing machine having a hollow frame, a main drive shaft rotatably mounted in said frame, a needle bar mounted in said frame for reciprocating and lateral swinging movements, drive means connecting said shaft and said needle bar for reciprocating the same, a cam shaft rotatably mounted in said frame and driven from said main shaft, a master cam fixed to said cam shaft, a member engaging said master cam, mechanism operable by said member to impart swinging movements to said needle bar, mid-point adjusting means to vary the location of said member t change the midpoint of said swinging movements, amplitude adjusting means associated with said mechanism to vary the effective movement of said member to adjust the amplitude of said swinging `movements and' means for driving a work feeding means from said shaft and including feed direction reversing mechanism, the combination of three cam units fixed to said cam shaft, each unit comprising a plurality of cams, a clip movably mounted on said frame adjacent each cam unit, a plurality of cam followers movably mounted on each clip, there being a separate follower for each cam of each unit, means connecting one clip with said mid-point adjusting means, means connecting the second clip with said amplitude adjusting means, means connecting the third clip with said feed direction reversing mechanism, a plurality of cam follower positioning members movably mounted on said frame there `being a separate positioning member for each cam follower, each positioning member engaging the associated cam follower, a lug on each positioning member, a cylindrical fixed to a shaft rotatably mounted in said frame adjacent said positioning members, a dial on said last named shaft exteriorly of said frame facilitating rotation of said cylindrical cam, a plurality of cam tracks on said cylindrical cam, each of said lugs engaging a separate track and one or more lobes on each track, whereby upon setting said dial for a desired stitch pattern, the appropriate lobes on said tracks will engage the associated lugs to move the associated positioning members and thereby move the associated cam followers into operative engagement with the associated cams of said cam units, rotation of said cam units serving to move said clips in accordance with the contour of the selected cams to adjust the mid-point adjusting means, the amplitude adjusting means and the feed direction reversing mechanish to provide the desired stitch pattern.

4. In a zigzag stitch sewing machine having a hollow rame, a main drive shaft rotatably mounted in said frame, a needle bar mounted in said frame for reciprocating and lateral swinging movements, drive means connecting said shaft and said needle bar for reciprocating the same, a cam shaft rotatably mounted in said frame and driven from said main shaft, a master cam fixed to said cam shaft, a member engaging said master cam, mechanism operable by said member to impart swinging movements to said needle bar, means for driving a work feeding means from said shaft and including feed direction reversing mechanism and means to adjust said swinging movements and said feed direction reversing mechanism to change the stitch pattern, the combination of a plurality of cam units fixed to said cam shaft, each unit comprising a plurality of cams, a clip movably mounted on said frame adjacent each cam unit, a plurality of cam followers movably mounted on each clip, there being a separate follower for each cam of each unit, means connecting said clips with the means to adjust said swinging movements and said feed direction reversing mechanism, a plurality of cam follower positioning members movably mounted on said frame adjacent said cam followers, there being a separate positioning member for each cam follower, each positioning member engaging the associated cam follower, a lug on each positioning member, a cylindrical cam fixed to a shaft rotatably mounted in said frame adjacent said positioning members, a dial on said last named shaft exteriorly of said frame for facilitating rotation of said cylindrical cam, a plurality of cam tracks on said cylindrical cam, each of said lugs engaging a separate track and one or more lobes on each track, whereby upon setting said dial for a desired stitch pattern, the appropriate lobes on said tracks will engage the associated lugs to move the associated positioning members and thereby move the associated cam followers into operative engagement with the associated cams of said cam units, rotation of said cam units serving to move said clips in accordance with the contour of the selected cams to adjust said swinging movement and the feed direction reversing mechanism to provide the desired stitch pattern.

5. In a zigzag stitch sewing machine having a hollow frame, a main drive shaft rotatably mounted in said frame, a needle bar mounted in said frame for reciprocating and lateral swinging movements, drive means connecting said shaft and said needle bar for reciprocating the same, a cam shaft rotatably mounted in said frame and driven from said main shaft, a master cam fixed to said cam shaft, a member engaging said master cam, mechanism operable by said member to impart swinging movements to said needle bar, means for driving a work feeding means from said shaft and including `feed direction reversing mechanism and means to adjust said swinging movements and said feed direction reversing mechanism to change the stitch pattern, the combination of a plurality of cam units fixed to said cam shaft, each unit comprising a plurality of cams, a clip movably mounted on said frame adjacent each cam unit, a plurality of cam followers movably mounted on each clip, there 'being a separate follower -for each cam of each unit, means connecting said clips with the means to adjust said swinging movements and said feed direction reversing mechanism, a cylindrical cam fixed to a sha-ft rotatably mounted in said frame adjacent said cam followers, a dial on said last named Shaft exteriorly of said frame for facilitating rotation of said cylindrical cam, a plurality of cam tracks on said cylindrical cam, there being a track `for each cam follower, one or more lobes on each track and means operable by said lobes to move said followers into operative engagement with the cams of said cam units, whereby upon setting said dial for a desired stitch pattern, the appropriate lobes on said tracks will move the associated cam followers into operative engagement with the associated cams of said earn units, rotation of said cam units serving to move said clips in accordance with the contour of the selected cams to adjust said swinging movements and the feed direction reversing mechanism to provide the desired stitch pattern.

6. In a zigzag stitch sewing machine having a hollow frame, a main drive shaft rotatably mounted in said frame, a needle bar mounted in said frame `for reciprocating and lateral swinging movements, drive means connecting said shaft and said needle bar for reciprocating the same, a cam shaft rotatably mounted in said frame and driven from said main shaft, a master cam xed to said cam shaft, a member engaging said master cam, mechanism operable by said member to impart swinging movements to said needle bar, means for driving a work feeding means from said shaft and including feed direction reversing mechanism and means to adjust said swinging movements and said feed direction reversing mechanism to change the stitch pattern, the combination of a plurality of cam units xed to said cam shaft, a clip movably mounted on said `frame adjacent each cam unit, a cam follower rnovably mounted on each clip, means connecting said clips with the means to adjust said swinging movements and said feed direction reversing mechanism, a cylindrical cam fixed to a Shaft rotatably mounted in said frame adjacent said cam followers, a 5 dial on said last named shaft exteriorly of said frame for facilitating rotation of said cylindrical cam, a plurality of cam tracks on said cylindrical cam, there being a track for each cam follower, one or more lobes on each track and means operable by said lobes to move said followers 1() into operative engagement with the cams of said cam units, whereby upon setting said dial for a desired stitch pattern, the appropriate lobes on said tracks will move the associated cam follo-wers into operative engagement with the associated cams of said cam units, rotation of 15 said cam units serving to move said clips in accordance with the contour of the selected cams to adjust said swinging movements and the feed direction reversing mechanism to provide the desired stitch pattern.

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