US3108555A

US3108555A - Device for controlling the needle-bar motion and the material feed in sewing machines

Info

Publication number: US3108555A
Application number: US36934A
Authority: US
Inventors: Engel Wolfgang
Original assignee: Anker Phoenix Naehmaschinen AG
Current assignee: Anker Phoenix Naehmaschinen AG
Priority date: 1959-06-19
Filing date: 1960-06-17
Publication date: 1963-10-29
Anticipated expiration: 1980-10-29
Also published as: GB947577A; NL246659A; CH395708A; DE1410544A1; BE588961A

Description

Oct. 29, 1963 w. ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED IN SEWING MACHINES Filed June 17, 1960 '7' Sheets-Sheet 1 Oct. 29, 1963 DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED IN SEWING MACHINES Filed June 17. 1960 '7 Sheets-Sheet 2 Jnven/or:

5 II. 4 9 On s 0 I M a 1/. 22 m. x m 2 ,L J T $L.L U d 2 0 2 Q 9 1:11 4 4 U H a l b@ \IQV r V/ I 1 7 5 E w M a 2 Oct. 29, 1963 w. ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED IN SEWING MACHINES Filed June 17. 1960 '7 Sheets-Sheet 3 Fig. 3

I v 71 F/ZIK 63 Oct. 29, 1963 w ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLEBAR MOTION AND THE MATERIAL FEED IN SEWING MACHINES Filed June 17. 1960 7 Sheets-Sheet 4' Fig.5 1+ 90 Jnvenfor:

L 3,108,555 EEDLE-BAR MOTION AND Oct. 29, 1963 W. ENGE DEVICE FOR CONTROLLING THE N THE MAT Filed June 17, 1960 ERIAL FEED IN SEWING MACHINES 7 Sheets-Sheet 5 Oct. 29, 1963 w. ENGEL 3,108,555

DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND THE MATERIAL FEED IN SEWING MACHINES Filed June 17. 1960 7 Sheets-Sheet 6 Jn ven fo r:

w. ENGEL 3,108,555 DEVICE FOR CONTROLLING THE NEEDLE-BAR MOTION AND Oct. 29, 1963 THE MATERIAL FEED IN SEWING MACHINES Filed June 17, 1960 7 Sheets-Sheet 7 Jnvenfor:

United States Patent DEVICE FUR CGNTRGLLING THE NEEDLE-BAR MGTEON AND THE MATERIAL FEED IN EW- 1N G MACHENES Woifgang Engel, Bielefeld, Germany, assignor to Ankar- Phoenix Niihmaschinen AG, Bielefeld, Germany, a corporation of Germany Filed June 17, 1969, Ser. No. 36,934 fiiairns priority, applieation Germany June 19, 1959 12 Claims. (Qt. 112-158) My invention relates to zigzag sewing machines and more particularly to a device for controlling the lateral needle-bar motion and the material feed in such machines.

There are known zigzag sewing machines with automatic control devices which, when producing fancy sewing stitches, control the position of the stitching area, the lateral stitching width and the material feed as well as the feeding direction by means of exchangeable or se lected control cams or similar control members. The just-mentioned parameter data, characteristic of a particular basic pattern to be produced automatically, can be modified with the aid of a manual means for setting the lateral stitching width, another manual means for setting the stitching area position, and a manual means for setting the feed motion. The manually controllable pattern modifications are made effective by changing the transmission ratio between the particular control cams and the respective slider or crank members actuated by the appertaining cam followers. Such manually adjusted pattern modification is possible only within the particular control range of the active control cams and hence within the scope of the basic pattern determined by the set of control cams.

Also known are manually actuable control devices which control the lateral stitching width, the stitch-area position and the amount of feed as well as the feed direction by means of a single handle adjustable in several setting ranges. In the known devices of this type the individual parameter data which, in the course of a fancy-stitch operation, are controlled in a given cyclical sequence by the just-mentioned handle, can likewise be additionally controlled by superimposed manual settings within the available range determined by the control cam.

However, the known automatically or manually actable control devices do not afford adjusting any desired parameter data, be it for the feed, the lateral stitching width, or the stitching-area position independently of, or beyond, the limitations of the basic pattern determined by the control cams.

It is an object of my invention to additionally ai'iord the possibility that the seamstress, before commencing a sewing operation, can pre-set certain parameter data, be it for the stitching length, the lateral stitching width, or the stitching-area position, and that she can make the presetting become effective to interrupt or supersede the normally cam-controlled sewing operation at any desired time or stage, particularly for sewing work in which, aside from straight or zigzag stitching, certain fancy-stitch work is to be done, such ts the sewing of buttonholes or ot er closed-upon-themselves patterns. In other words, it is an object of my invention, when alternately doing such two kinds of sewing work, to make it unnecessary for each change in work to perform the inconvenient and time-consuming operations required for first determining and then inserting the particular control means that correspond to the desired type of sewing.

It is another object of my invention to improve zigzag sewing machines by widening the setting range available to the manual setting means, so that the machine can be preset to any parameter values beyond the range Patented Get. 29, 1963 ice of a particular control cam inserted or built into the machine.

To achieve these objects, my invention is based upon the provision of a zigzag sewing machine in which the lateral stitching width, the stitch-area position, and/ or the material feed for the production of fancy stitch patterns of the type closed upon themselves is controlled automatically or manually in dependence upon the selected setting of a single adjustable handle. According to the invention, the single handle or equivalent manual setting means in such a machine controls the transmission memher that cooperates with the automatic cam or other automatic control mechanism in order to permit any desired adjustable control magnitude to become effective.

This and more specific features of my invention will be described in the following with reference to the embodiment of a zigzag sewing machine according to the invention illustrated by way of example on the accompanying drawings in which:

FIG. 1 is a front view of the sewing machine seen from the operators place.

FIG. 2 is a top view of the machine onto the plane denoted by Illl in FIG. 1, the top cover of the machine being removed.

FIG. 3 is a cross section along the line III-III in FIG. 1.

FIG. 4 is a rear view of the stitch-pattern control device which forms part of the same sewing machine.

FIG. 5 is a cross section along the vertical center plane of the control device according to FIG. 4, the section being taken along the line VV in PlG. 8.

FIG. 6 is a schematic and perspective bottom view of the manual control member for setting the position of the stitching area.

FIG. 7 is a schematic perspective view of the control device seen from the front, the handle for shifting the stitch area being removed.

FIG. 8 is a front view of the control device, including the handle for shifting the stitch area.

FIG. 9 shows the feed-control mechanism with the appertaining control cam set for manual control of the material feed.

FIG. 10 shows the control cam and cam follower for controlling the stitch-area position.

FIG. 11 shows a double cam for stitching-width control, the cam being set for manual control of the stitching width.

FIG. 12 shows the position of the same double cam in the position occupied during sewing of buttonholes.

FIG. 13 shows the stitch-area control cam of FIG. 10 set for sewing of buttonholes.

FIG. 14 illustrates the feed-control cam of FIG. 9 in the position occupied during sewing of buttonholes.

FIG. 15 shows details of the manual control means for setting the stitching length.

FIG. 16 is a front view and E6. 17 a partly sectional top view of the manual control means for setting the stitching direction.

The illustrated zigzag sewing machine comprises a hollow Standard and arm structure 1 (FIGS. 1, 3) in which the horizontal main shaft 2 is journaled. The shaft 2 carries a handwheel 2a designed as a belt sheave to be driven from a motor in conventional manner. The other end of shaft 2 is linked by a crank mechanism 2b, also conventional, to the vertically reciprocable needle bar 13 of the machine. The main shaft 2 is also in driving connection with a controllable mechanism, described below, which causes the needle bar, while reciprocating vertically, to oscillate transversely of the material feed direction when zigzag stitches are to be produced. Such driving connection comprises a pair of worm gears 3, 4- which connect shaft 2. with a vertical cam shaft 5 (FIGS. 1, 2) journaled in a bearing 6 in the arm structure above the main shaft 2. Secured to the upper end of cam shaft is an eccentric driver cam 7 straddled by the fork portion of a bifurcated lever 8 whose opposite end is pivoted at 9 to the drive l ver 14} of the needle-bar swing member 11. The drive lever it) is fastened to the swing member 11 which is rotatable about two coaxial, pointed dowel pins 12, 12 (FIG. (.2) and which carries the vertically reciprocating needle bar 13. As shown in FIG. 2, the fork lever 8 carries a pivot pin 14 on which a slider 15 is rotatable. The slider is displace able in a guide slot in of a guide block 17 which has a cylindrical pivot pin (not illustrated) rotatably joining the guide block with one end of a displacing lever 18. Lever 13 is rotatable about a pin 1? stationarily fastened in the arm structure it.

When the guide slot 16 of block 17 extends at a right angle to the geometric connecting line between the respective axes of

pivot pins

9 and 14, the fork lever 8 will merely oscillate about the axis of pivot pin 3 due to rotation of the eccentric 7 without any displacement of lever 8 and pin 9 along the longitudinal axis of the forked lever 8. Hence the swing member 11 and the needle bar 13 are not laterally deflected transversely of the material feeding direction. Consequently, with this positioning of the guide slot 16, the sewing machine is set for straight stitching.

However, if t 15 position of the guide slot 16 about the pivot axis of the guide block 17 is changed, the fork lever 8, when being driven by drive earn 7, not only oscillates about the axis of pivot 9 but also reciprocates longitudinally of the lever 8. Consequently, the swing member 11 and the needle bar 13 now perform lateral deflections of greater or lesser extent in a direction transverse to that of the material feed, so that zigzag stitches are produced.

In order to elfect such a displacement of the guide slot 16, the guide block 17 has an arm 34 which carries a pivot pin 33 engaging one end of a connecting member 31. The other end of member 31 is linked by a pivot pin 32 to one arm of a bell-crank lever whose other arm is denoted by 29'. The

angular lever

20, 20 is rotatable on a pivot pin 19 stationarily secured to the arm structure 1 of the machine.

The displacing lever 18, the arm 34 of the guide block 17, the connecting member 31, and the arm 20 of the

angular lever

20, 20 form together a parallelogram mechanism. Fastened to the end of the lever arm 26 is a pin 26 to which one end of a connecting rod 27 is linked. The other end of rod 27 is fastened to a connecting rod 41 by means of screws 43 (FIGS. 1, 2). The connecting rod 41 has an elongated slot traversed by the two screws 43 to permit adjusting the longitudinal spacing. The free end of the connecting rod 41 is linked to an angular camfeeler lever 44 by means of a pivot pin 45 (FIGS. 2, 4). The lever 44 is rotatably mounted on a pin 46 (FIG. 4) secured to a cup-shaped carrier 47 (FIGS. 4, 5, l) which in turn is secured to the arm structure 1 by screws 48, 49 (FIG. 8) and which covers a frontal opening Stl (FIG. 5) of the arm structure 1.

When the guide block 17 with slot '16 is angularly displaced from its inactive position, the sewing machine produces zigzag stitches extending symmetrically to the central position. If the stitching area is to be displaced so that zigzag or straight stitches are produced at the right or left from the central position, the displacing lever 18 (FIG. 2) must be turned about the pivot pin 19. For this purpose the displacing lever 18 is joined at one end with a lever arm which has a linking pin 36 engaging one end of a connecting rod 39. The other end of rod 39 carries two screws 42 by means of which the connecting rod 43 is fastened to the connecting rod 39. The connecting rod 49 possesses a longitudinal slot (not shown) traversed by the two screws 42 to permit adjusting the relative position of

rods

39 and 44 The other end of connecting rod 44 is linked by a pivot pin 51 (FIGS. 2, 4) to a cam-fceler lever 52 rotatably mounted on the same pivot pin 46 as the lever The abovementioned two adjusting means of the zigzag control device are controlled by handles 99 and 163 (FIGS. 5, l, 3). The handle 99 serves to manually control the lateral stitching width or to set the machine either for zigzag or straight stitching. The handle 103, designed as a knob, permits shifting the stitching area. The machine is further provided with a knob 136 (FIG. 3) adjustable to a plurality of active positions for controlling the stitching length in the longitudinal stitching direction, and a bandle 132 for controlling the stitching direction, ie, to set the machine for forward or reverse stitching. Details of these four controls will be described further below. It should be understood, however, that while manually actuable control means are shown, the machine may be additionally equipped with cam mechanisms for automatically controlling the zigzag sewing operation in accordance with a desired pattern, such automatic zigzag control means being known as such and described, for example, in my copending application Serial No. 7,938, filed February 10, 1960, for Zigzag Sewing Machine With Fancy- Stitch Selector, assigned to the assignee of the present invention.

Fastened on the main shaft 2 is a belt sheave 55 (FIG. 3). Another belt sheave 57 is secured to a gripper drive shaft 58 journalled within the bottom structure 59 of the machine whose table top forms the sewing surface for supporting the material to be sewed. A belt 56 trained about the two sheaves 5'5 and 57 drives the gripper drive shaft 51 at the speed ratio 1:1. The gripper drive shaft 58 carries an eccentric cam 60 straddled by a mouth portion of a lever 61 which has one end linked by a crank pin 62 to an arm 63 fastened on a feed control shaft 64. The other end of lever 61 carries a pivot pin 7%} on which a slider 71 is rotatable. The slider 71 glides in a slot 72 of a guide block 73 which has a cylindrical pin 89 (FIG. 1) rotatably mounted in the machine base structure 59. When the guide slot 72 of block 73 extends at a right angle to the geometric connecting line between the respective axes of pins and 60, the fork lever 61 will reciprocate about the pivot pin 62 while the arm 63 remains at rest. However, when the guide slot 72 of block 73 is angularly displaced from the just-mentioned position, the arm 63 and the feed control shaft 64 are caused to oscillate about the axis of shaft 64.

The feed control shaft 64 extends parallel to the gripper drive shaft 58 longitudinally of the sewing machine and up to the working range of the sewing tools in the known manner. Provided at the needle-adjacent end of the feed control shaft 64 is a lever arm 65 (FIG. 3) to which a feeder bar 67 is linked by a pivot pin 66. The other end of feeder bar 67 has a mouth portion straddling a lifting member 68. The feed motion is imparted to the material to be sewed, by means of a serrated head 69 which is fastened by screws to the top portion of the bar 67. It will be understood that by these devices the oscillating motion of the feed control shaft 64 is transmitted through the arm 65, the feeder bar 67 to the serrated healid 69 which produces the feeding motion of the materia To permit turning the slot 72 of guide block 73 about the axis of pivot pin 89, the block 73 is provided with an arm 7 which carries a pin 75. A pusher rod 73 (FIG. 3) has its lower end linked to arm 74 of block 73 by means of pin 75. The upper end of rod 78 has a longitudinal slot 78 (FIGS. 15, 16). An eccentrically mounted pin is rotatably journalled in the hub 128 of a cam-feeder lever 127. One end of the pin 125 protrudes to the outside through a slot 134 (FIG. 17) in the wall 131 of the standard portion of the machine arm structure. The eccentricity of the pin 125 can be set and fixed from the outside by means of a set screw 129, thus making it possible to compensate for manufacturing tolerances. Fastened to the protruding end of the pin 125 by means of a set screw 133 is the above-mentioned 5 handle 132 for setting the stitching direction (FIGS. 17, 3). The axial position of pin 1125 and pusher rod 78 relative to the machine housing is secured by means of spring rings 126, 13% (FIGS. 17, 15).

The cam-feeler lever 127 is rotatable on a pivot pin 135 (FIGS. 16, 17, l) fastened to the arm structure of the machine. The lever 127 has a curved portion 127a so as to straddle a pair of

cams

133, 138a (FIG. 16) which serve for controlling the stitching length in the feed direction. The two cams are secured on a shaft 137 (FIGS. 16, 17, 1) which is rotatably mounted in the machine housing and which carries the manual stitchlength setting means 136 designed as a knob and provided with a scale of indicia (FIGS. 17, 3). The

cams

138, 138a cooperate with two feeler tips of the lever 127 127a. The cam contours of cams 138 and 133a are identical and are angularly displaced from each other the same amount as the two feeler tips relative to the axis of shaft 137. In the angular position of

cams

138, 138a shown in FIG. 1, the two feeler tips abut against respective lobes of the two cam contours. With this setting, the feeler lever 127 is in its mid-position and cannot be turned about the pin 135 by means of the stitch-direction control handle 132. Now, the cipher (FIG. 3) on the indicating scale of knob 136 is located opposite a fixed marking (not shown) on the standard portion of the machine housing structure and designates the inactive position, and the other numerals designate active positions.

The cam contour of each of

cams

138 and 138a, as shown in FIG. 16, recedes inwardly at a slow rate from the outermost point of the cam lobe and gradually merges with a grea er rate of directional change down to the smallest diameter of the cam. With such a cam contour, small stitching lengths can be adjusted very accurately as is required during forward and reverse sewing of the sidebar (caterpillar) portions of a buttonhole. I

'Fastened to the cup-shaped carrier 47 (FIG. is a hub 93 in which a hollow shaft 94 is journalled. The shaft 24 protrudes inwardly into the interior of the hollow arm structure 1 where it carries three

cams

85, 86 and 87 (FIGS. 5, 9, 11 to 14). Cam 35 coacts with a cam feeler or follower 122 for feed control; and the two

cams

86 and 87 coact with feeler lever 44 for controlling the lateral stitching width, as more fully explained below. The opposite end of shaft 94 protrudes out of the arm structure 1 and carries a disc 98 (FIG. 5) on which a handle 99 (FIGS. 5, l, 3, 7, 8) for setting the lateral stitching width is mounted. Handle 29 thus controls the

cams

85, 86, 87. Coaxially journalled in the bore of the hollow shaft 94 is an intermediate sleeve 95 which carries a lever arm 97 (F163. 4, 5) which has a fork portion straddling the pivot pin 46 (FIG. 4). A central pin 96 is coaxially journalled in the bore of the intermediate sleeve 95 and protrudes into the interior of the arm structure 1 where the pin 96 carries a cam 38 (FIGS. 5, 7, which cooperates with a cam feeler or follower 52 (FIGS. 4, 10) for controlling the position of the stitching area. The other end of pin 96 (FIG. 5) protrudes out of the arm structure 1 and carries a knob 1113 (FIGS. 5, 6, 8) fas tened by means of a set screw 1164. Turning of knob 103 has the effect of rotating cam 88 so as to shift the center axis of the seam or sewing pattern being produced.

When the position of the seam (stitch-area position) is adjusted to the mid-position by corresopndingly setting the knob 1113, the feeler tip 115 (FIGS. 10, 4) of the feeler lever 52 is approximately in the middle of the cam portion 113 of cam 88, and the feeler tip 114 (FIGS. 4, 10) of lever 52 is approximately in the middle of the contour portion 11? of cam 88. The

cams

86 and 87 cooperate with the feeler lever 44 (FIGS. 4, 11). The feeler tip 112 of feeler lever 44 presses against the cam 87, and the feeler tip 113 rests against the cam 86.

When the handle 99 for setting the size of the zigzag stitches (lateral stitching width) is in the position shown in FIG. 11, the sewing machine produces straight stitches. When the handle 99 is turned to the right, the

cam portions

120, 121 of

respective cams

86 and 87 turn the feeler lever 44 and thereby vary the size of the zigzag stitches (FIG. 11). The cam 35 (FIG. 9) does not participate in setting the stitching length by hand. For that reason the feeler tip of feeler lever 122 does not rest against cam '85. The cam is illustrated in FIG. 9 in its inactive position, and in FIG. 14 in its active position.

The tfecler lever 122 (FIGS. 4, 9) for setting the stitching direction by means of the handle 132 (FIGS. 17, 3) is mounted on a pivot pin 84 (FIGS. 4, 9) fastened in the cup shaped carrier 47. Likewise rotatable on pivot pin 84 is a lever 83 which carries a pin 108 protruding into a circular opening 108 (FIG. 4) of the feeler lever 122. The diameter or size of opening 1% is larger than that of pin 108 so that the angle between the two

levers

122 and 83 is variable within certain limits. A spring 109 abutting against the two

levers

122 and 83 has the tendency to reduce this angle to the minimum. The spring 109 is stronger than the spring 91 (FIG. 1) and acts in opposit=ion thereto. The :lever 83 carries at its peripheral end a pin 85 (FIG. 4) to which one end of a pull rod 82 is linked. The other end of rod $2 engages the eccentric pin (FIGS. 15 to 17).

If the seamstress Wants to switch the sewing machine from any straight stitching or zigzag stitching to buttonhole sewing, she pulls the handle 99 (FIGS. 3, 5), thus turning it about the pin 101) (FIG. 5 on disc 98 in opposition to the action of the spring 123-, and subsequently, but by the same manipulation, turns the handle about the axis of the hollow shaft 94 by about (FIG. 7). The handle 99 is extended beyond its pivot 100, and the extension 102 (FIGS. 5, 7) is ring-shaped and surrounds the hollow shaft 94. The upper end of the ring-shaped extension 102 carries a lag 101 which is biased by a spring 123 (FIG. 5) to normally engage a groove 107 (FIGS. 5, 6) in the stitch-displacing knob 103. As the handle 99 is being turned about the hollow shaft 94, the lug 1G1, gliding along the groove 10 7 (FIG. 6), ultimately snaps into a recess 106 of knob 103 due to the action of spring 123. Now the

cams

85, 86, 87 and 88 are clutched together to form a single package. In this position of handle 9 and cam package 85, =86, "87, 88, the

feeler tips

112, 113, 114, 115 and 122 (FIG. 4) are located opposite respective cam-contour portions which, during corresponding turning of the

cam package

85, 86, 87, 88 by means of the handle 99, control the lateral stitching width, the stitchingarea position, the movement of the fabric-feeding mechanism in such a manner that a buttonhole is produced by virtue of the above-described angular displacement of the handle 99, regardless of whether the machine was and remains other-wise set for straight stitching or automatic zigzag stitching. Such buttonhole sewing proceeds as follows.

After the seamstress has latched the handle 9% with the

cam package

85, 86, 87, 88 in the manner described above, she turns the handle 99 sequentially to dilferent angular positions corresponding to the positions A, B, C illustrated by broken lines in FIG. 12. First the handle 99 is set to position A where it abuts against a stop 111 (FIG. 12). In this position, the

cams

85, 86, 87, S8 and the feele-

r levers

44, 52 and 83 occupy the positions illustrated in FIGS. 12., 13 and 14; and the machine sews the left-hand side bar (caterpillar of the buttonhole pattern while operating in reverse stitching operation. In this position, the cam 85 (FIG. 14) turns the feeler lever 122 outwardly; and the spring 109 places the lever 83 as well as the connecting rod 82 and hence the feeler tip of feeler lever 127 into follower contact with the cam 138 in opposition to the acting of the spring 91. The cam 85 does not serve the purpose to set the magnitude of the stitching length during forward and reverse stitching, but its purpose is to cause the feeler tips of the

feeler lever

127, 127a to become engaged with the corresponding cams 13 8 and 1 8:: within the range of stitch sizes from approximately zero to 1 millimeter. This stitch size is adjustable by means of the knob 136 (FIGS. 3, 17). The radial height of the lobe of cam 35 is so dimensioned that the feeler lever 122, when being turned outward, is lifted a sufiicient extent to place the pin 188 approximately in the middle of the bore 108 when the feeler tip of feeler lever 127 abuts against the contour of cam 133.

When the desired length of the buttonhole side bar (caterpillar) is reached, the seamstress, during sewing, switches the handle 99 to the mid-position B for the purpose of sewing the buttonhole terminating (cross-bar) stitches. The displacing lever 13 (FIG. 2) and hence the needle bar are now also in mid-position. This position is marked or secured by a catch (not illustrated) in known manner, so that the seamstress can readily find this rnidposition by feel only. Now, the

cams

85, 86, 87 and 38 have placed the feeler levers 44, 52 and 122 in such a position that the sewing machine produces look stitches in forward stitching operation. In this position B of handle 99, the cam 85 (FIG. 9) is turned to such an extent that the feeler lever 122 is turned inwardly by springs 91 and 109, unimpeded by the contour shape of cam 85. Such inward turning motion of feeler lever 122 takes place until the feeler tip of feeler lever 127m, under the action of spring 91 (FIGS. 1, 16), is placed into contact with the cam 138m.

After any desired number of buttonhole terminating stitches are completed, the seamstress places the handle to position C (FIG. 12) where it abuts against a stop 110. This causes the

cams

86, 87, S8 to control the feeler levers 44, 52 so that the right-hand side bar (caterpillar) of the buttonhole pattern is being sewed. Since in position C of handle 99, the cam 85 and the feeler lever 122 are likewise out of engagement with each other, the feeler tip of feeler lever 127a remains in engagement with cam 138a. Hence the machine again operates with forward stitching.

This is followed by sewing the second cross bar. The seamstress now turns the handle 99 to the mid-position B. The

cams

85, 86, S7 and 83 now occupy the same position as during the sewing of the first cross bar. Consequently the sewing machine, during forward feed of the material, produces the second group of lock stitches that terminate the buttonhole. To prevent the last stitches from loosening, the handle 99 can be turned against the stop 111 (position A) during continued sewing operation. Then, according to FIGS. 12, 13, 14, with reverse operation of the material feeder, a few additional side-bar stitches are sewed after the last terminating stitches are completed. Thereafter the buttonhcle is finished.

If the seamstress wants to shift from buttonhole sewing to the sewing of any desired straight or zigzag stitches, she pulls the handle 99 about the pin 100 thus placing the lug 101 out of the range of the groove 166, and then turns the handle 99 approximately 180 about the axis of hollow shaft 94'. Thereafter buttonhole or other closed-pattern control device is set out of action, and the machine is again switched over for the sewing of any desired straight or zigzag stitches (FIGS. 9, i0, 11).

Consequently for switching the sewing machine from any straight or zigzag sewing to buttonhole sewing, or vice versa, only one manual control member, namely the han- :dle 99, need be actuated.

I claim:

1. A zigzag sewing machine comprising reversible material feed means, guide means, a needle bar axially reciprocable in said guide means for stitching operation, said guide means being oscillatable transversely of the feed direction of said feed means, a control mechanism having rotatable cam means for controlling the feed and having cam-controlled transmission means connected to said feed and guide means for producing zigzag patterns, a con- .trol apparatus cooperating with said cam means and transmission means for controlling the movement of said feed means, said cam means being selectively movable into respectively first and second conditions for respective cam control and manual sewing pattern control, said cam means in said first condition being operatively engaged with said transmission means for controlling only the feeding direction of said feed means and in said second condition being operatively disconnected from said transmission means, said control apparatus comprising a manually actuable device having means for selectively adjusting said device into an inactive and a plurality of active posi ions for manually selectively determining the stitching length throughout the sewing of the pattern.

2. In a zigzag sewing machine according to claim 1, said transmission means comprising cam follower means in engagement with said rotatable cam means of said zigzag pattern control mechanism when said manually actuable device is selectively adjusted into said active or inactive positions, and means for disengaging said cam means and said follower means from each other so that said cam means can be in said second condition and disengaged from said follower means when said manual device is in said active or inactive positions.

3. In a zi zag sewing machine according to claim 1, said control mechanism comprising a first manually adjustable member for controlling the lateral stitching width, a second manually adjustable member for controlling the stitching-area position, and a third manually adjustable member for controlling the material feed, one of said manually adjustable members forming part of said selective adjusting device for manually setting said device to said active and inactive positions respectively.

4. In a zigzag sewing machine according to claim 1, said control mechanism comprising a first manually adjustable member for controlling the lateral stitching width, at second manually adjustable member for controlling the stitching-area position, and a third manually adjustable member for controlling the material feed, said first member forming part of said selectively adjusting means for manually setting said device to said active and inactive positions respectively, said cam means comprising a first rotatable cam structure for controlling the lateral stitching width, said first cam structure being connected with said first manually adjustable member to be rotated there by, said cam means further comprising a second cam structure for shifting the stitching area, said second cam structure being coaxially rotatable relative to said first cam structure and being connected with said second manually adjustable member to be controlled thereby, a third cam structure coaxially joined with said first cam structure to be likewise controlled by said first member, releasable latch means joining said first and second memers when said first member is set to a given rotational position relative to said second member, whereby rotation of said first member over a given range causes joint rotation of said first, second and third cam structures.

5. In a zigzag sewing machine according to claim 1, said manually actuable device comprising two coaxial cams angularly displaced from each other and rotatable conjoin-tly with each other, a handle member connected with said two cams for setting them to a selected rotational position, a cam feeler member in follower engagement with both of said cams, and a plurality of stitch parameter control members manually adjustable and in controlling controlling connection with said cam feeler member.

6. In a zigzag sewing machine according to claim 5, said control mechanism comprising a first cam for controlling the stitching-area position, a second control cam for control of the lateral stitching width, and said rotatable cam means defining a third control cam for feed control, said transmission means having linking mechanisms connecting said first and second control cams to said oscillatable guide means and having further linking mechanisms connecting said third control cam to said feed means, said first and second and third control cams being 9 coaxial, said third control cam having a cam follower yieldingly and operatively connected to said cam feeler member for controlling the latter.

7. In a zigzag sewing machine according to claim 5, comprising a rotatable handle member connected with said feeler member and adiustable relative thereto for compensation of manufacturing tolerances, a linking member eccentrically joined with said handle member, and rod means connecting said linking member with said manually aotuable device of said closed-pattern control apparatus.

8. In a. zigzag sewing machine according to claim 5, comprising linking means connecting said cam feeler member with said material feed means whereby said handle member for rotationally setting said two coaxial cams controls the stitching length through said feed means, and said said manual stitch-parameter control means comprising a stitch-direction control handle.

9. In a zigzag sewing machine according to claim 8, said material feed means comprising a drive shaft, an eccentric on said shaft and an eccentric-follower lever pivoted at one end, a slider rotatably mounted on said lever, a slide-way member in which said slider is displaceable, and a material-feeding mechanism linked to said follower lever to be operated from said drive shaft in dependence upon the angular position of said slide-way member, said linking means comprising a connecting rod connecting said cam feeler member with said slide-Way member for constrainedly adjusting the latter about its axis of rotation relative to said lever.

10. In a zigzag sewing machine according to claim 8, comprising a controlling connection between said feeler member and said carn follower of said third control cam for feed control, said connection including first biasing spring means, said linking means between said slide-way member and said feeler member comprising second biasing spring means, said first spring means being predominating relative to said second spring means for overriding control.

11. A zigzag sewing machine according to claim 1, said manually actuable device including stitching-length setting means, said transmission means including a feeler member engageable with said cam means in said active condition of the latter, and linking means connecting said feeler member with said stitching-length setting means for operat-tively connecting the latter with said feed and guide 10 means, whereby said stitchingdength setting means can manually selectively and variably determinate the stitching length throughout every phase of the sewing of said closed patterns.

12. In a zigzag sewing machine having a needle bar, a material feeder means and a plurality of adjustable control members and slide block means for controlling movements of said needle-bar and for controlling the direction of movements of said material feeder means, said control member having rotatable cam means for controlling the feed, said cam means being selectively movable into respectively first and second conditions for respective cam control and manual sewing pattern control, said cam means in said first condition being operatively engaged with said transmission means for controlling only the feeding direction of said feed means and in said second condition being operatively disconnected from said transmission means, a manually actuable device selectively adjustable between an inactive and a plurality of active positions for pre-setting given constant magnitudes for determining maximum movements of said feeder means, transmission I means connecting said adjustable control members with said slide block means for controlling said movements, said manually :actuable device being operably interposed in said transmission means between at least one of said adjustable control members and said slide block means, said device being under control of said one of said control members to become effective in the direction determined by said one control member.

References Qited in the file of this patent UNITED STATES PATENTS (Corresponding US. 3,033,138, May 8, 1962) 564,305 Italy June 14, 1957

Claims

1. A ZIGZAG SEWING MACHINE COMPRISING REVERSIBLE MATERIAL FEED MEANS, GUIDE MEANS, A NEEDLE BAR AXIALLY RECIPROCABLE IN SAID GUIDE MEANS FOR STITCHING OPERATION, SAID GUIDE MEANS BEING OSCILLATABLE TRANSVERSELY OF THE FEED DIRECTION OF SAID FEED MEANS, A CONTROL MECHANISM HAVING ROTATBLE CAM MEANS FOR CONTROLLING THE FEED AND HAVING CAM-CONTROLLED TRANSMISSION MEANS CONNECTED TO SAID FEED AND GUIDE MEANS FOR PRODUCING ZIGZAG PATTERNS, A CONTROL APPARATUS COOPERATING WITH SAID CAM MEANS AND TRANSMISSION MEANS FOR CONTROLLING THE MOVEMENT OF SAID FEED MEANS, SAID CAM MEANS BEING SELECTIVELY MOVABLE INTO RESPECTIVELY FIRST AND SECOND CONDITIONS FOR RESPECTIVE CAM CONTROL AND MANUAL SEWING PATTERN CONTROL, SAID CAM MEANS IN SAID FIRST CONDITION BEING OPERATIVELY ENGAGED WITH SAID TRANSMISSION MEANS FOR CONTROLLING ONLY THE FEEDING DIRECTION OF SAID FEED MEANS AND IN SAID SECOND CONDITION BEING OPERATIVELY DISCONNECTED FROM SAID TRANSMISSION MEANS, SAID CONTROL APPARATUS COMPRISING A MANUALLY ACTUABLE DEVICE HAVING MEANS FOR SECLECTIVELY ADJUSTING SAID DEVICE INTO AN INACTIVE AND A PLURALITY OF ACTIVE POSITIONS FOR MANUALLY SELECTIVELY DETERMINING THE STITCHING LENGTH THROUGHOUT THE SEWING OF THE PATERN.