US3229655A

US3229655A - Automatic zig-zag stitch sewing machine

Info

Publication number: US3229655A
Application number: US297994A
Authority: US
Inventors: Eguchi Yasukata
Original assignee: Janome Sewing Machine Co Ltd
Current assignee: Janome Corp
Priority date: 1963-07-11
Filing date: 1963-07-11
Publication date: 1966-01-18
Anticipated expiration: 1983-01-18

Description

1966 YASUKATA EGUCHl AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE 6 Sheets-Sheet 1 Original Filed Aug. 23. 1960 INVENTOR- Jan. 18, 1966 YASUKATA EGUCHI AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE 6 Sheets-Sheet 2 Original Filed Aug. 23. 1960 g Jug/ 212.

Jan. 18, 1966 YASUKATA EGUCHI AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE 6 Sheets-Sheet 5 Original Filed Aug. 23. 1960 MN ww MN 8 v Q M m 2 g INVENT0R.I

WQ .m

1966 YASUKATA EGUCHI AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE 6 Sheets-Sheet 4 Original Filed Aug. 23, 1960 INVENTOR. W

Jan. 18, 1966 YASUKATA EGUCHI AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE 6 SheetsSheet 5 Original Filed Aug. 23. 1960 A 7 1; E w 7 3., VJ #2 "N h 0 3 1 a E v Q 4 x 5 Jan. 18, 1966 YASUKATA EGUCHI AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE 6 Sheets-Sheet 6 Original Filed Aug. 25. 1960 meta-MN United States Patent 3,229,655 AUTOMATIC ZIG-ZAG STITCH SEWING MACHINE Yasukata Eguchi, Kunitachimachi, Kitatamagun, Japan, assignor to Janome Sewing Machine Co., Ltd., Tokyo,

apan Continuation of application Ser. No. 51,408, Aug. 23, 1960. This application July 11, 1963, Ser. No. 297,994 8 Claims. (Cl. 112-158) This invention relates to an automatic zig-zag stitch sewing machine, so constructed that when an operator depresses one or more selected push buttons of a series of buttons arranged on the machine, a corresponding number of related cam followers are brought into engagement with cooperating selected pattern cams turnably mounted on a cam shaft. When the machine is running, specific zig-zag motion is transmitted from said selected cam or cams through said cam follower or followers and transmission mechanism to a needle bar mechanism, to pivotally reciprocate the needle in the lateral direction, for purpose of producing zig-Zag stitching.

The present application is a continuation of my application Serial No. 51,408, filed August 23, 1960 and now abandoned, entitled, Automatic Zig-Zag Stitch Sewing Machine.

The main object of the invention is to provide a novel zig-zag sewing machine, which provides a possibility to produce a complete buttonhole stitching by manipulating one and the same control knob.

Another object of the invention is to provide a novel zig-zag sewing machine, wherein the necessary reversal of material feed necessary for producing a buttonhole stitching is simultaneously carried into eifect with control for positioning the stitching.

Another object of the invention is to provide a zig-zag sewing machine of the kind above referred to, which is highly efficient in its function, yet amazingly simple, reliable and sturdy in its design.

The invention in its broadest aspect resides in 'an automatic zig-zag stitch sewing machine, characterized by such combination of: a cam mounted on a conventional camshaft; a cam follower mounted so as to cooperate therewith, when necessary and connected to a needle bar; and an adjusting means for positioning said cam follower so as to bring the latter into engagement with said cam, or into disengagement from said cam or to modify the engaging condition of said cam follower with said cam, thereby to shift the position of the needle bar and of the zig-zag stitch sewing in the lateral direction.

Various further and more specific objects, features and advantages of the invention will appear from the description given below, taken in connection with the accompanying drawings illustrating by way of example a preferred embodiment of this invention.

In the drawings:

FIGURE 1 illustrates a perspective front view of the sewing machine according to the invention;

FIGURE 2 shows a horizontal section of a substantial part of the machine;

FIGURE 3 is a cross-section taken on the line III-III in FIGURE 2;

FIGURE 4 shows an exploded perspective view of several working parts of the machine;

FIGURE 5 is a perspective view of the stitch control mechanism of the machine;

FIGURE 6 shows an enlarged cross-section taken on the line VIVI in FIGURE 2;

FIGURE 7 is a further cross-section similar to FIGURE 3, taken on the line VIIVII in FIGURE 2;

FIGURE 8 shows an enlarged longitudinal section of the free end of the machine arm;

FIGURE 9 is a perspective view of the button-hole stitching device;

FIGURE 10 is a fragmentary side view of a cam and a cam follower cooperating therewith and embodied in the sewing machine according to the invention;

FIGURE 11 shows a feed-control cam employed in the machine;

FIGURES 12 and 13 are explanatory diagrams, showing a buttonhole stitching made by the machine according to this invention.

Now, referring to the accompanying drawings, especially FIGURE 2 thereof, reference numeral 1 represents a conventional upper drive shaft of the zigzag sewing machine, a cam shaft 2 being rotatably mounted in parallel with the drive shaft as in the conventional manner. The camshaft 2 is driven through a gear train 6871 (FIGURE 5) constituting a reduction gearing from the drive shaft 1, the camshaft being provided with a stitch cam packet 3 comprising a plurality of individual cams having various peripheral configurations. Reference numeral 4 represents in general a group of push buttons operable from outside the front wall of the machine arm 66, the number of these push buttons being equal to that of the stitch cams 3. The butt-on group 4 comprises an upper row of buttons 4a and a lower row of buttons 41'). An arm 5 is attached to each upper push button 4a at its upper part, while a somewhat differently shaped arm 6 is firmly fixed to each lower push button 4b at its lower part, as most clearly seen from FIGURE 5. The arm 5 of push button 4a is formed with a boss 8 at its inward-1y projecting end, as well as with a leg 10. The boss 8 is formed therein with a bearing opening 7, while the leg 10 is formed at its upper part with a projection 11 having a bearing opening 11a receiving a pin 12. At the lowermost end of the leg 10, there are provided a recess 10a and a projection 10b, the purpose of which will be described hereinafter more in detail. The arm 6 of push button 4b is connected integrally with leg 10 at its lower part,

other elements

7, 8, 11, 11a, 10a and 10b being equally provided as in the case of push button 4a, although not shown. A supporting shaft 9 is supported in parallel to the camshaft 2 in the machine, and the upper series and the lower series of push buttons 4a and 4b being suspended alternatively from the camshaft, which passes through the bearing opening 7 in each boss 8, as most clearly seen from FIGURE 5. The same number of cam followers 13 and stitch cams 3 are provided. Each of cam followers 13 is pivotally mounted on .a pin 12, which is press-fitted in the bore 7 of boss 8, projecting therefrom for the desired mounting. The cam follower 13 is integrally formed with lower and upper engaging portions 13a and 13b, the upper portion 13a adapted to cooperate with the related stitch cam 3, while the lower portion 13b is always kept in engagement with the lower projecting end 18a of a motion-transmitting operating member shown to be a bar 18 pivotally mounted on a shaft 19, which is fixed at one end thereof to a stationary member 66 mounted on the machine arm 66. The opposite end of bar 18, seen in the longitudinal direction, is fixed by means of screws 21 onto a pin 20, which is fixed to an operating arm 22, the purpose of which will be described hereinafter in detail. The arm 22 is operatively connected with a conventional needle bar for control thereof as will be described hereinafter in detail. A spring 14 is provided for each of the push buttons 4a, 4b to pivotally bias the respective button in counter-clockwise direction as viewed in FIGURE 3, the upper leg 14a of spring 14 resiliently abutting against an angle bar 16 fixed at both ends onto stationary members 66 by screws 15, while the lower leg 14b of the spring is in pressure engagement with the back surface of the related push button 4a or 4b.

p In parallel with the camshaft 2, there is arranged a stop bar 23, which is pivotally mounted at its opposite ends by means of stationary pins 24 and 25, respectively. A spring 26 is mounted on pin 25, one end 26a of the spring engaging with the stop bar 'and the opposite end 26b abutting against a stationary member fixed to the machine arm 66, so that the bar 23 is urged to turn in the counterclockwise direction in FIGURE 3. The stop bar 23 is formed thereon with a longitudinal groove 23a, which is adapted to receive the projection a formed on the lowermost end of leg 10 of a push button 4a or 4b, when the buttons are pushed in. A stationary stop bar 28 fixedly mounted on the inside wall of the machine frame 66 abuts the leg 10 of the push button 4a or 4b when the button is returned to its normal position.

With the above explained construction, any suitable stitch design can be selected out as follows:

Firstly, an operator observes stitch patterns represented diagrammatically on push buttons and selects one pattern. Now, assuming that the operator pushes-in the corresponding button, it is caused to turn in the clockwise direction in FIGURE 3 against the action of the spring 14 mounted on the stationary shaft 9. As already described, the related cam follower 13 is pivotally supported on the pivot means 12 mounted on projection 11 of the button, and the cam follower will be caused to engage by its engaging pawl portion 13a the related stitch cam 3. At the same time, the engageable projection 10b is caught by the longitudinal recess 23a on the rockable stop bar 23, thus arresting the button so that returning movement under the influence of spring 14 is effectively prevented. Thereafter, the cam follower 13 is kept in pressure contact by its pawl portion 13a with the operative peripheral surface of the cooperating stitch cam. During rotation of the cam the cam follower will be caused to pivotally reciprocate about its supporting pivot pin 12 according to the various lifts of cam periphery, while the opposite engaging pawl portion 13b is kept in pressure contact with the cooperating contact surface 18a of transmission bar 18, which is thereby caused to reciprocate angularly. Such rocking motion is thus transmitted from the bar 18 to the operating member 22, which is, as already referred to operatively connected to the needle bar 30 (FIGURE 8) for lateral reciprocation thereof, as will be described hereinafter in detail.

When the operator has completed a desired kind of zig-zag stitching, and then he wishes to sew a different kind of stitch, he may, maintaining the above mentioned conditions, push-in a further selected push button corresponding to a newly selected stitch design. The thus advanced leg 10 of the pushbutton rides with its lowermost projection 10]) upon the inclined surface on the rockable stop bar 23, which is thus angularly displaced to some degree in clockwise direction in FIGURE 3, until the projection 10b is brought into engagement with the recess 23a formed on the stop bar 23.

During the clockwise turning movement of the stop bar 23, the engaged push button is disengaged and returns under the influence of the restoring spring 14 to its normal inactive position in which it is held by engagement with the stationary stop bar 28.

When it is desired to sew a composite stitch design comprising two or more standard stitch forms represented on push buttons, the operator depresses simultaneously two or more corresponding buttons in the similar way as was described hereinbefore. In this case, also, the pivotable stop bar 23 is turned to a degree by the pushed-in buttons, which will be engaged by the stop bar 28 and thus kept in their advanced operative positions, while, on the other hand, the already advanced button or buttons are being returned to their normal positions, after disengagement from the stopper bar 28.

Next, referring especially to FIGURE 8, the motion transmitting mechanism extending from the operating member 22 to the conventional needle bar operating mechanism will be now described:

Reference numeral 30 represents a needle bar holder, which supports the needle 31 being arranged to be vertically reciprocated from the drive shaft 1 through the intermediary of a reciprocating motion mechanism, which is of the conventional design but not shown for simplicity of the drawing. On the upper part of the holder 30 a pin 32 is fixedly mounted, and a connecting bar 33 is pivotally connected at its forked end 33a-33b with the pin 32. On the opposite or inward end of the connecting bar 33, a plate 34 is fixed by means of screws 35, the plate having an inward extension, the end of which is shaped as an engaging edge 34a kept always in contact with the upper surface of the arm member 22. A pin 36 fixed on a horizontal projection 330 made integral with the connecting bar 33, and cooperates with the forked end 37a of a Z-shaped, amplitude-adjusting lever 37 pivotally mounted on a stationary member fixed with the machine arm 66. The opposite end of the lever 37 is formed with an arm, as illustrated in FIGURE 2, to which is pivotally connected a link 40 by means of a pivot 39, while in the opposite end of the link is formed a longitudinal slot 40a, through which extends guide pin 41 screwed into a stationary member fixed with the machine arm 66 for guidance of the link. As most clearly seen from FIGURE 7, an amplitude-adjusting shaft 42 is rota-tably mounted in the machine arm 66, a knob 43 being fixed on one end of the shaft 42 projecting from the front wall of the machine arm 66, for manual control of the shaft as desired by the operator. On the opposite end of the shaft 42, a link 45 is fixed at one end thereof, while the opposite end of the link is pivotally connected with one end of an operating link 44. The opposite end of the operating link is fixed onto a depending projection 40b formed at an intermediate portion of the aforementioned link 40 by means of a screw 4617, as most clearly seen. from FIGURE 2. A pair of stroke-limiting stops 47 are arranged vertically in a separated relation from each other and fixed on a stationary part integral with the machine arm 66. These stops 47 are adapted for cooperating with a projection 22a formed on the operating arm 22 for limiting the operative range of the movement of arm 22. These

parts

47 and 22a are most clearly seen from the FIGURE 8. Spring 30 normally urges holder 30 with the entire needle bar support to turn until

arm

33, 34, 34a has turned arm 22 to a position in which projection 22a abuts the lower stop 47.

If one or more push buttons 4 are pushed-in, the related cam follower or followers are brought into and kept in contact with the thus selected and related stitch cam or cams 3, as described hereinbefore. During rotation of the cam packet 3, the operating member 18 is caused to angularly reciprocate according to the cam configuration or composed configurations on the corresponding stitch cam or cams. The arm member 22 fixed on the pin 20, which is fixed on one end of the operating member 18, is thus caused to angularly reciprocate and since the engaging edge 34a is always kept in contact with the upper surface of the free end of the pivotable operating arm 22, motion is thus transmitted through plate 34 and connecting bar 33 to needle-bar holder 30 causing lateral reciprocation thereof. Thus, the needle 31 is reciprocated simultaneously in the lateral as well as in the vertical direction.

When the operator turns the knob 43 manually in one or the other direction, to realize a desired amplitude of stitch, the shaft 42 will turn to a corresponding degree. Thus, motion is transmitted through the link 45 fixed, as already described, on the opposite end of the shaft 42, and to the operating link 44. Since the opposite end of the operating link 44 is rigidly connected with the depending projection 40b of link 40, the latter is thus shifted to the right or left in FIGURE 2, being guided by a fixed pin 41 engaging with the cooperating slot 40a in link 40.

Since the opposite end of link 40 is pivoted to the armshaped end portion of amplitude-adjusting lever 37 by means of pivot pin 39 and the lever is pivotally movable about pivot pin 38, motion is transmitted to the lever, the latter being thus caused to rotate to a corresponding degree around the pivot 38. This rotation causes the pin 36 engaging with the forked end 37a of lever 37 to move up or down in FIGURE 2, as the case may be, whereby the connecting bar 33 is shifted correspondingly and the needle-bar holder is turned about the pin 32. At the same time, the opposite engaging end 34a of extension of connecting bar 33 is shifted correspondingly nearer to or farther away from the pivoted point of operating arm 22, so that the amplitude of the zig-zag stitching is accordingly reduced or increased according to the turning direction of knob 43. For obtaining pressure contact of the engaging end 34a with the upper surface of operating arm 22, a spring is provided, which urges the needle-bar holder 30 to turn in the clockwise direction in FIGURE 8. g

The buttonhole arrangement characterizing substantially the present sewing machine will now be described in detail.

As shown in FIGURES 2, 5 and 9, an additional or buttonhole stitch cam 48 is mounted on the cam shaft 2 at the extremity of stitch cam packet 3 and an operating arm 49 is pivotally mounted on one end portion of stationary shaft 9, which supports, as already explained hereinbefore, two rows of push buttons 4a, 4b. The operating arm 49 is formed integrally with a collar 49b, on which a wire spring is mounted. One end of the spring engages the depending portion of arm 49, while the opposite end abuts against the stationary member 16 connected to the machine arm.

A cam follower 51 is pivoted by means of a pin 68 on the operating arm 49. One end pawl portion 51a of cam follower 51 is an engaging portion adapted to engage with the periphery of buttonhole cam 48, while the opposite end pawl portion 51b is an operating portion kept in pressure contact with operating member 18, in the similar manner described hereinbefore in connection with the stitch cam packet 3. Since spring 30' urges operating member 18 with shaft 20 to turn in counterclockwise direction as viewed in FIG. 10, cam follower 51 is turned in clockwise direction until portion 51a en gages cam 48, or if this is not possible due to the position of support 49, until projection 22a rests on the lower stop 47 as explained with reference to FIG. 8.

A transverse shaft 53 is turnably supported in the ma chine arm 66 and projects partially through the front wall of the arm, a buttonhole stitch adjusting knob 52 being fixed on the projecting shaft end. A cam 54 is fixed on shaft 53, which cam is formed on its periphery with operating

surfaces

54a, 54b, 54c and 54d corresponding to representations OFF, 1 and 2 on the dial surface 77 fixed on the front surface of the machine from 66. A crankshaft 72 is tumably mounted on stationary parts of machine arm 66, although the mounting details are not illustrated in the drawing for the sake of clarity thereof. The crankshaft is provided at one end with a crank 73, an engageable pin 74 projecting from the crank as shown in FIGURES 2 and 9. Substantially in a symmetrical manner, a further projecting pin 76 is fixed on an oppositely shaped crank 75, which pin is kept in pressure contact with the depending free end 49a of operating arm 49. By manually turning the knob 52, the first mentioned engageable pin 74 is brought into and kept in contact with any desired one of

operating cam surfaces

54a, 54b, 54c and 54d.

When it is desired to make a complete buttonhole stitching, the knob 52 is turned from its OFF to 1- position, in which pin 74 is located on the lowest camface in the clockwise direction as shown by an arrow X in FIGURE 9, cam 54 is rotated in the same direction and thus the engaging pin 74 rides up along the inclined 6 surface 54a, until it is seated upon the adjacent cam surface 5412. In this case, the pin 74 is pushed toward the operator, thereby the related crank 73 is rotated to a corresponding degree in the same direction as the pin, while the opposite end crank 75 is turned in the opposite direction, and the attached pin 76 is carried along. The lower end 49a of operating arm 49 is thus pushed inwardly by the engaging pin 76 and the cam follower 51 is brought nearer to the buttonhole stitch cam 48. In the OFF position of knob 52, support 49 is a position in which pivot means 60 of cam follower 51 is spaced such a distance from cam 48 that portion 51a is spaced from cam 48 while cam follower 51 is turned all the way in clockwise direction until

arm

22, 22a rests on the lower stop 47. Therefore, the turning cam 48 has no influence on cam follower 51. The related parts are so designed and arranged that when the pin 74 has engaged with the cam surface 54b in the above mentioned manner in the position I, the cam follower 51 will occupy the position relative to the related cam, as illustrated by a full line in FIGURE 10 while the end portion 510 was spaced from cam 48 in the OFF position of knob 52. When the operator starts the machine for sewing under these conditions, small zig-zag stitching as shown at the left side in FIGURES l2 and 13 will be produced in the advancing direction on one side of the button hole since the upper end 51b of cam follower 51 oscillates member 18. When a desired length of stitching forming one fringe of the button hole has thus been completed, the operator turns the knob 52 until the numeral 2 thereon is brought into coincidence with a pointer 78 on the knob 52. During this turning movement of knob 52, the adjusting cam 54 is further rotated in the same clockwise direction as before, the engaging pin 74 being thus guided along the inclined cam surface 540 and brought into engagement with the cam surface 54d. In this way, the crank 75 is further advanced to the related cam 48, until the cam follower 51 occupies a position represented by a chain-dotted line in FIGURE 10 while turning about a fulcrum formed by portion 51a engaging cam 48. Now, more specifically considering the last-mentioned shifting step, the pivot pin 60 supporting cam follower 51 on operating arm 49 travels along a circular path having a radius r equal to the distance between pivot 60 and shaft 9 so that the center of cam follower 51 moves along the same circle, while cam follower 51 turns about

fulcrum

51a, 48 so that portion 51b performs a composite movement to the position shown in dotted lines. During this movement, portion 51b displaces and turns bar 18 so that the needle support 30 is laterally displaced through

members

22, 34, 34a, 33, 32 against the action of spring 30' as shown in FIGS. 2 and 8. The needle moves correspondingly through a long stitch amplitude ls-Zs. Transmission or operating member 18 moves along a circular path having a radius ra determined by the distance between the contact point of engaging pawl 51a and a projection on buttonhole stitch cam 48 and the first men tioned pawl 51b. When the engaging pin 74 has been brought into engagement with the cam surface area 54d, cam follower 51 has been deflected an angle 0a shown in FIGURE 10 from the preceding operative step and kept in general in this position. During shifting of the engaging pawl 51!) of cam follower 51 with transmission bar 18, from the position illustrated in FIGURE 10 by full line to that shown by chain-dotted line, the full-width closing stitching ls-2s in FIGURE 13 are produced in the advancing direction so that the end of the button hole is closed by a series of small stitches while the feeding of the material is stopped. After the completion of the full-width stitching, and when cam follower 51 is in the position shown in dotted lines, the short zig-zag stitches 2s in FIGURES l2 and 13, respectively, are made. In this case, the pin 74 is kept in contact with cam surface area 54d and the cam follower 51 also operates at the position designated by a chain-dotted line in FIGURE 10,

so that the other side of the buttonhole is stitched. The feeding direction of the material is, however, reversed during stitches 2s as will be described more in detail hereinafter. When the reverse zig-zag stitching has the desired length of the buttonhole, the operator must turn the knob 52 in the opposite or anti-clockwise direction in FIGURE 9, to bring the numeral 1 instead of 2 thereon into position. By this procedure, the pin 74 slides over the inclined cam surface 540 to recede to a predetermined degree. The opposite pin 76 is moved to the corresponding degree toward the front of the machine and bar 18 turns and follows under the action of spring 30'. During this receding movement of pin 74 in contact with inclined cam surface 540, the full-width stitches as shown by ls-1s in FIGURE 13 are produced at the other end of the buttonhole in' the opposite direction. In this way, a complete buttonholestitching may be successfully produced. In positions 1 and 2 of knob 52, and while the cam follower 51 engages cam 48, spring 30' of the needle bar assembly urges pawl Sla against cam 48 so that pawl 51a enters the recesses of cam 48 and is oscillated to cause bar 18 and the needle bar assembly to oscillate correspondingly. When the pin 74 is then brought into engagement with the cam surface area 5417, the related parts are ready for sewing a further buttonhole stitching as explained hereinbefore. The cam follower 51 occupies in this case the operative position shown by a full line in FIGURE 10.

Next, the above mentioned reversing stitching will be described more in detail:

As shown in FIGURE 9, a cam 55, see FIG. 11, is mounted on the opposite end of adjusting shaft 53, while a cam follower roller 59 in contact with the cam is turnably mounted on a lever 58 mounted at its one end on an eccentric shaft 57, which is fixed by means of a fixing screw onto a suitable portion of machine arm 66, although the details are not shown. By turning and securing shaft 57, the location of the fulcrum of lever 53 can be adjusted. At the opposite end of the lever 58, a supporting member 60 is pivotally suspended therefrom by means of a pivot 65 and the member 60 is in turn connected with a further supporting member 62 by means of a spring strip 61, as clearly seen from both FIGURES 6 and 9. The latter member 62 is fixed to a feed adjusting means 63, which serves as in the conventional manner to control the direction of material feed. Additionly, a tension spring 64 (FIGURE 6) is provided between feed adjuster 63 and a proper portion of machine arm 66, the accurate portion being, however, not shown in the drawing.

With the above mentioned arrangement, the cam follower roller 59 is always kept in pressure contact with the cooperating cam 55 under the influence of tension spring 64. When the operator turns the knob 52, as above described, to bring mark 2 from 1 in position, the cam 55 will be carried along, whereby the roller 59 is raised and thus the lever 58 is turned about its pivot 57 to a corresponding degree in the counter-clockwise direction seen in FIGURE 9. Motion is thus transmitted through member 60, strip 61 and further member 62 to feed adjusting means 63, which is thereby brought into its reverse feed position. In this way, the required reverse feed for reverse zig-zag stitches of a buttonhole stitching as at 23 in FIGURES l2 and 13, respectively, can be effectively produced.

It will be clear from the foregoing that with the first mechanism including adjustable knob 52, cam 54, pins 74 and 75, and the like, the cam follower 51 may be changed in its position alternatively, and with the second mechanism including cam 55, lever 58, cam follower roller 59, feed adjusting means 63 and the like, the control of the direction of the feed of the stitched fabric necessary for producing a complete buttonhole stitching is obtained.

Referring especially to FIGURE 11, which illustrates a front view of the above mentioned cam 55, the pitch of buttonhole stitches will now be explained:

The cam 55 is so arranged that the OFF, 1 and -positions on the dial 77 correspond exactly to the contact points of the adjusting cam 55. On the other hand, when the operator turns knob 52 from OFF to l, the cam 55 is simultaneously caused to rotate, as was already described hereinbefore and the roller 59 is brought into engagement with the cam surface area 55a, which is designated in its size and configuration to adjust the feed adjusting means 63 to the necessary fine pitch. With this fine pitch, the advancing zig-zag stitching will be made. Next, when the operator manipulates knob 52 to turn it from "1 to 2, the cam 55 will be further turned in the same direction as before, and the roller 59 will cooperate with the cam surface area 55b in FIGURE 11, so that lever 58 is further pivotally raised to cause the necessary reverse feed of material. The cam surface area 55b is so shaped and designed as to operate the feed adjusting means 63 for providing a fine pitch for zig-zag stitching in this reversed mode of operation. As already described, the pin 57 is shaped in an eccentric, so that possibility is given to make additional adjustment of the pitch error of buttonhole stitching by turning the eccentric and fixing the thus newly set position thereof.

As hereinbefore described, according to the present invention, the operator can engage a cam follower with or disengage it from a rotatable cam, by turning a knob, and it is possible to shift the line or row of zig-zag stitches in the lateral direction by changing the mode of engagement of the said follower with the cooperating cam. In addition, of the above-mentioned shifting and positioning the needle bar assembly may be carried into effect smoothly and continuously. Simultaneously with the manipulation of the adjusting knob, a further control member such as a cam for controlling the speed of feed is effectively controlled to provide during the advancing or the reversing stitching, a fine pitch adjustment of the zig-zag stitches. By these measures, a highly complicated pattern of stitching as required for producing a complete buttonhole stitching can be realized in a simple and efficient manner. Nevertheless, the sewing machine according to this invention is reliable in its function, simple and sturdy in its design and easy in its manipulation.

While there has been shown and described a particular embodiment of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and, therefore, the appended claims are intended to cover all such changes and modifications within the true spirit and scope of the invention.

The invention having thus been described what is claimed and for which protection by Letters Patent is desired, is:

1. A buttonhole stitching device comprising, in combination, a frame; a stitch cam mounted on said frame for turning movement; a support having a cam follower mounted thereon for turning movement about an axis, said cam follower having an engaging portion located opposite said stitch cam, and an operating portion; pivot means mounted on said frame for supporting said support with said cam follower for angular movement to and from said stitch cam; a movable operating member located opposite said operating portion; pivot means stationarily mounted on said frame for supporting said operating member for angular movement; a needle bar support mounted for lateral movement between a first lateral position and a second lateral position, and being operatively connected to said operating member to laterally move while moving with said operating member; spring means for urging said needle bar support toward said first lateral position whereby said operating member is turned; stop means on said frame for blocking lateral movement of said needle bar support and of said operating member; and manually operated control means for moving said support between an inoperative position in which said axis is farthest spaced from said stitch cam and in which said cam follower is spaced from said cam while said needle bar support is blocked by said stop means, and in a continuous movement between a first operative position in which said axis is nearer to said stitch cam and in which said engaging portion engages said stitch cam so that said cam follower is oscillated whereby said operating member and said needle bar support are oscillated to make small stitches about said first lateral position of said needle bar support, and a second operative position in which said axis is nearest to said stitch cam, said spring means urging said cam follower in said first and second operational positions to turn until said engaging portion abuts said stitch cam so that said cam follower turns about a fulcrum formed at the point of contact between said engaging portion and said stitch cam whereby said operating portion oscillates said operating member and said needle bar support to make small stitches about said second lateral position of said needle bar support so that in said first and second operative positions small stitches on the sides of the buttonhole are made, while during shifting of said support from said first operative position to said second operative position and vice versa said operating member is displaced by said cam follower so that said needle bar support is moved by said operating member between said first and second lateral positions to effect transverse stitches connecting said short stitches at the ends of the buttonhole.

2. A buttonhole stitching device comprising, in combination, a frame; a stitch cam mounted on said frame for turning movement; a support having a cam follower mounted thereon for turning movement about an axis located intermediate the ends of said cam follower, said cam follower having at one end an engaging portion located opposite said stitch cam, and at the other end an operating portion; pivot means mounted on said frame for supporting said support with said cam follower for angular movement to and from said stitching cam; a movable operating member located opposite said operating portion; pivot means stationarily mounted on said frame for supporting said operating member for angular movement; a needle bar support mounted for lateral movement between a first lateral position and a second lateral position, and being operatively connected to said operating member to laterally move while moving with said operating member; spring means for urging said needle bar support toward said first lateral position whereby said operating member is turned; stop means on said frame for blocking lateral movement of said needle bar support and of said operating member; and manually operated control means including a manually operated member, a control cam having three stepped portions, and cam follower means cooperating with said stepped portions and being connected to said support for moving said support between an inoperative position in which said axis is farthest spaced from said stitch cam and in which said cam follower is spaced from said cam while said needle bar support is blocked by said stop means, and in a continuous movement between a first operative position in which said axis is nearer to said stitch cam and in which said engaging portion engages said stitch cam so that said cam follower is oscillated whereby said operating member and said needle bar support are oscillated to make small stitches about said first lateral position of said needle bar support, and a second operative position in which said axis is nearest to said stitch cam, said spring means urging said cam follower in said first and second operational positions to turn until said engaging portion abuts said stitch cam so that said cam follower turns about a fulcrum formed at the point of contact between said engaging portion and said stitch cam whereby said operating portion oscillates said operating member and said needle bar support to make 10 small stitches about said second lateral position of said needle bar support so that in said first and second operative positions small stitches on the sides of the buttonhole are made, while during shifting of said support from said first operative position to said second operative position and vice versa while said cam follower means moves from one of said stepped portions to another of the stepped portion said operating member is displaced by said cam follower so that said needle bar support is moved by said operating member between said first and second lateral positions to effect transverse stitches connecting said short stitches at the ends of the buttonhole.

3. A buttonhole stitching device as set forth in claim 2 wherein said manually operated means includes a knob and a shaft secured to said knob; wherein said control cam has inclined faces between said stepped portions, and is secured to said shaft for turning movement; and wherein said support is mounted for turning movement about an axis parallel to said first mentioned axis of said cam follower.

4. A buttonhole stitching device comprising, in combination, a frame; a stitch cam mounted on said frame for turning movement; a support having a cam follower mounted thereon for turning movement about an axis located intermediate the ends of said cam follower, said cam follower having at one end an engaging portion located opposite said stitch cam, and at the other end an operating portion; pivot means mounted on said frame for supporting said support with said cam follower for angular movement to and from said stitch cam; a movable operating member located opposite said operating portion; pivot means stationarily mounted on said frame for supporting said operating member for angular movement; a needle bar support mounted for lateral movement between a first lateral position and a second lateral position, and being operatively connected to said operating member to laterally move while moving with said operating member; spring means for urging said needle bar support toward said first lateral position whereby said operating member is turned; stop means on said frame for blocking lateral movement of said needle bar support and of said operating member; manually operated control means for moving said support between an inoperative position in which said axis is farthest spaced from said stitch cam and in which said cam follower is spaced from said cam while said needle bar support is blocked by said stop means, and in a continuous movement between a first operative position in which said axis is nearer to said stitch cam and in which said engaging portion engages said stitch cam so that said cam follower is oscillated whereby said operating member and said needle bar support are oscillated to make small stitches about said first lateral position of said needle bar support, and a second operative position in which said axis is nearest to said stitch cam, said spring means urging said cam follower in said first and second operational positions to turn until said engaging portions abuts said stitch cam so that said cam follower turns about a fulcrum formed at the point of contact between said engaging portion and said stitch cam whereby said operating portion oscillates said operating member and said needle bar support to make small stitches about said second lateral position of said needle bar support so that in said first and second operative positions small stitches on the sides of the buttonhole are made, while during shifting of said support from said first operative position to said second operative position and vice versa said operating member is displaced by said cam follower so that said needle bar support is moved by said operating member between said first and second lateral positions to effect transverse stitches connecting said short stitches at the ends of the buttonhole; feeding means for feeding material under said needle bar support; reversing means connected to said feeding means for reversing the feeding direction thereof and a feed control ll a member connected to said reversing means for operating the same and having a first position in which said feeding means feed said material in one direction and a second position in which the feeding means feed said material in the opposite direction, said feed control member being connected to said control means for movement with the same and being in said first and second positions when said support is in said first and second operative positions, respectively.

5. A buttonhole stitching device comprising, in combination, a frame; a stitch cam mounted on said frame for turning movement; a support having a cam follower mounted thereon for turning movement about an axis located intermediate the ends of said cam follower, said cam follower having at one end an engaging portion located opposite said stitch cam, and at the other end an operating portion; pivot means mounted on said frame for supporting said support with said cam follower for angular movement to and from said stitch cam; a movable operating member located opposite said operating portion; pivot means stationarily mounted on said frame for supporting said operating member for angular movement; a needle bar support mounted for lateral movement between a first lateral position and a second lateral position, and being operatively connected to said operating member to laterally move while moving with said operating member; spring means for urging said needle bar support toward said first lateral position whereby said operating member is turned; stop means on said frame for blocking lateral movement of said needle bar support and of said operating member, manually operated control means including a manually operated member, a control cam having three stepped portions, and cam follower means cooperating with said stepped portions and being connected to said support for moving said support between an inoperative position in which said axis is farthest spaced from said stitch cam and in which said cam follower is spaced from said cam while said needle bar support is blocked by said stop means, and in a continuous movement between a first operative position in which said axis is nearer to said stitch cam and in which said engaging portion engages said stitch cam so that said cam follower is oscillated whereby said operating member and said needle bar support are oscillated to make small stitches about said first lateral position of said needle bar support, and a second operative position in which said axis is nearest to said stitch cam, said spring means urging said cam follower in said first and second operational positions to turn until said engaging portion abuts said stitch cam so that said cam follower turns about a fulcrum formed at the point of contact between said engaging portion and said stitch cam whereby said operating portion oscillates said operat ing member and said needle bar support to make small stitches about said second lateral position of said needle bar support so that in said first and second operative positions small stitches on the sides of the buttonhole are made, while during shifting of said support from said first operative position to said second operative position and vice versa while said cam follower means moves from one of said stepped portions to another of the stepped portion said operating member is displaced by said cam follower so that said needle bar support is moved by said operating member between said first and second lateral positions to effect transverse stitches connecting said short stitches at the ends of the buttonhole; feeding means for feeding material under said needle bar support; reversing means connected to said feeding means for reversing the feeding direction thereof; and a feed control member connected to said reversing means for operating the same and having a first position in which said feeding means feeds said material in one .direction and a second position in which the feeding means feeds said material in the opposite direction,

12 said feed control member being connected to said manually operated member for movement with the same and being in said first and second positions when said support is in said first and second operative positions, respectively.

6. A device as set forth in claim 5 wherein said feed control member is a cam; and including a cam follower engaging said last-mentioned cam and operatively connected to said reversing means.

7. In a buttonhole stitching device, in combination, a frame; a stitch cam mounted on said frame for turning movement; a support having a cam follower mounted thereon for turning movement, said cam follower having an engaging portion cooperating with said stitch cam and an operating portion; means mounted on said frame and supporting said support with said cam follower for movement toward and away from said stitch cam; a movable operating member located opposite said operating portion; means stationarily mounted on said frame for supporting said operating member for angular movement; a needle bar support mounted for lateral movement between a first lateral field position and a second lateral field position, and being operatively connected with said operating member to be laterally moved by the same; and control means having two end positions and being manually movable between the same, said control means being connected with said support for moving said support while said engaging portion of said cam follower engages said stitch cam so that said cam follower is oscillated and oscillates said operating member and said needle bar support at a constant amplitude, said support being in two terminal positions, respectively, when said control means is in said end positions so that said needle bar support is oscillated about said two lateral field positions whereby lateral stitches are made on the sides of a buttonhole, while during manual movement of said support between said terminal positions said operating member is displaced by said cam follower so that said needle bar support is moved by said operating member under manual control from one of said lateral field positions to the other lateral field position while effecting overlapping stitches connecting said lateral stitches and being produced by said stitch cam engaging said engaging portion of said cam follower.

8. In a buttonhole stitching device, in combination,

a frame; a stitch cam mounted on said frame for turning movement; a support having a cam follower mounted thereon for turning movement, said cam follower having an engaging portion cooperating with said stitch cam and an operating portion; pivot means mounted on said frame and supporting said support with said cam follower for turning movement toward and away from said stitch cam; a movable operating member located opposite s-aid operating portion; pivot means stationarily mounted on said frame for supporting said operating member for angular movement; a needle bar support. mounted for lateral movement between a first lateral field position and a second lateral field position, and being operatively connected with said operating member to be laterally moved by the same; and control means having two end positions and being manually movable between the same, said control means being connected with said support for moving said support while said engaging portion of said cam follower engages said stitch cam so that said cam follower is oscillated and oscillates said operating member and said needle bar support at a constant amplitude, said support being in two terminal positions, respectively, when said control means is in said end positions so that said needle bar support is oscillated about said two lateral field positions whereby lateral stitches are made on the sides of a buttonhole, while during manual movement of said support between said terminal positions said operating member is displaced by said cam follower so that said needle bar support is moved by said operating member under manual control from one of said lateral filed positions to the other lateral field position while elfecting overlapping stitches connecting said lateral stitches and being produced by said stitch cam engaging said engaging portion of said cam follower.

References Cited by the Examiner UNITED STATES PATENTS 767,478 8/1904 Haywood 112158 3,126,849 3/1964 Giesselmann et al. 112-158 JORDAN FRANKLIN, Primary Examiner. ROBERT V. SLOAN, Examiner.