US3006297A - Sewing machine with zigzag stitching attachment - Google Patents

Description

Oct. 31, 1961 E. URSCHELER 3,006,297

SEWING MACHINE WITH ZIGZAG STITCHING ATTACHMENT Filed Jan. 13, 1956 5 Sheets-Sheet 1 Flg.2 E III 47 3s 2758 42 '22 T 46 24 kl 26 14 49 4a 1 1 IE I H [MAL l/eacwfzfe Oct. 31, 1961 E. URSCHELER 3,006,297

SEWING MACHINE WITH ZIGZAG STITCHING ATTACHMENT Filed Jan. 13, 1956 5 Sheets-sheet 2 Fig.3 1 Fig-7 B/fM/ 7 7 Oct. 31, 1961 E. URSCHELER 3,006,297

SEWING MACHINE WITH ZIGZAG STITCHING ATTACHMENT Filed Jan. 15, 1956 5 Sheets-Sheet 5 3,006,297 1C6 Patented Oct. 31 196-1 3,006,297 SEWING MACHINE WITH ZIGZAG STIICHING ATTACHlVIENT Emil Urscheler, Dietikon, Zurich, Switzerland, assignor to Turissa-Naehmaschinenfabrik A.G., Dietikon, Zu-

rich, Switzerland Filed Jan. 13, 1956, Ser. No. 559,033 Claims priority, application Switzerland Mar. 5, 1955 2 Claims. (Cl. 112-158) The present invention relates to a sewing machine with zigzag stitching attachment, in which the overstitch width of the zigzag seam or the displacement of the respective centre line to the left or right of a normal line or the stitch distance is manually or automatically variable by at least one control member in order to produce needle stitches according to various cycles.

The sewing machine according to the invention is characterized by several signal lamps each of which is associated with a definite needle stitch cycle, and by electric contact means adapted to automatically close the electric circuit of that signal lamp which corresponds to the needle stitch cycle each time set.

Further features of the invention will appear from the claims, the description and the accompanying drawing in which there are shown by pure way of example some preferred forms of embodiment incorporating the invention.

FIG. 1 shows a lateral view of a domestic sewing machine with free work-supporting arm;

FIG. 2 shows a part of the same machine with standard partly broken away;

FIG. 3 is a cross-section taken on the line III-III of FIG. 2, but on alarger scale with respect thereto;

FIG. 4 is a similar cross-section taken on the line IV IV of FIG. 2, also on a larger scale with respect thereto;

FIG. 5 is a sectional view of a drum-shaped control member of the machine;

FTG.'6 shows a similar sectional view at another place of the same control member;

FIGS. 79 show indicators of a number of signal lamps of the machine;

FIG. 10 shows diagrammatically a part of another example of embodiment of the sewing machine with differently designed control members;

FIG. 11 also shows diagrammatically a part of a third example of embodiment of the machine,

FIG. 12 illustrates another detail of this machine, and

FIG. 13 shows a diagram of the electrical circuit.

The sewing machine as illustrated in FIGS. 1 and 2 has a casing or standard 10, wherein a horizontally extending main shaft 11 is rotatably arranged in the usual Way. Said shaft carries at one end a handwheel 12 and at the other end a crank 13 which is coupled in known manner to the needle bar by mea'ns of a link 14 in order to effect the up and downstroke of the bar. The needle bar 15 is in its longitudinal direction displaceably located in a guide member 16 being at its upper end pivotally supported on standard 10 by means of a joint 17 so as to permit the needle bar 15 to reciprocate also laterally, in addition to its up and downstroke, for the purpose of making zigzag stitches. Through joint 18 the guide member 16 for the needle bar 15 is connected to a link 19 being in turn joined to an oscillating lever 21 mounted on a pivot 20. Said lever is rigidly mounted on an axle 22 which extends horizontally and at right angles to the main shaft 11, being rotatably supported within standard 10 and displaceable endwise as shown in FIG. 4. Said axle 22 passes displaceably through an eye of the lever 21 itself prevented from moving in longitudinal direction of axle 22. This axle 22 has a flat-portion, 23, being thus partly of non-circular cross-section, whereas the eye of lever 21,

receiving the axle 22, possesses a correspondingly noncircular passage opening for the axle 22.

Rigidly mounted on main shaft 11 is a Worm 25 meshing with a wormwheel 26. The latter is fixed on a shaft 27 which extends parallel to the axle 22 and is journaled within standard 10, one end of said shaft 27 being supported within standard part 10a detachable from the remaining standard 10 as shown in FIG. 3. The standard part 10a is designed as a threaded piece engaging a suitable female thread in the remaining standard 10. Seated on shaft 27 are two drum- like control members 28 and 29 provided with several endless circumferential grooves 30 and 31 respectively. The drums 28 and 29 are thus rigidly mounted for rotation with the shaft 27, since this has a flattening and hence a non-circular cross-section, Whereas the central openings 32 of the drums possess a similar non-circular cross-section, as visible from FIGS. 5 and 6 in the example of the drum 28. Upon detachment and removal of the standard part 10a, one drum 29 may be taken out of the machine and, if desired, be replaced by another. The drum 29 is thus exchangeable.

The axle 22 has clamped thereon a sleeve 35 carrying at each end a feeler 36 and 37 respectively. By suitable endwise displacement of the axle 22, brought about by a knob 38 attached to the axle end, the feeler 36 may selectively be brought into engagement with one of the circumferential grooves 30 of the drum 28. In quite a similar way the other feeler 37 may selectively be brought into engagement with one of the circumferential grooves 31 of the other drum 29. The arrangement of the drums 2'8 and 29 on the one hand and of the feelers 36 and 37 on the other hand is such, that always only one feeler or the other can be engaged, that is to say that never both feelers can engage at a time any of the circumferential grooves 30 and 31. An extension 39 of the pivot 20 is engaged by one end of a coil spring 40 (FIG. 4), the other end being anchored to the standard 10 in a way not shown. The spring 40 is in tension and tends to move the lever 21 and thus the axle 22 so as to cause the feelers 36 and 37 to abut on one or the other drum 28 and 29 respectively. The feeler engaging in one of the grooves 30 and 31 consequently remains always in contact with the corresponding groove bottom under the action of spring 40.

The drum 28 has one circumferential groove 30 the bottom of which is everywhere at the same distance from the axis of rotation of the drum 28 and is consequently cylindrical, i.e. circular in the cross-section of the drum. If the feeler 36 lies in this groove, its position remains unchanged during rotation of the drum 28, and no lateral reciprocation will consequently be imparted to the needle bar 15. The sewing machine is then set for sewing ordinary loc-k stitches.

All other grooves 30 and 31 have a bottom, the distance of which varies from the axis of rotation of the respective drum in such a way that the feelers 36 and 37 lying in said grooves are caused to'oscillate on rotation of the drum, which oscillation in turn causes lateral deflection of the needle bar 15 via lever 21 and link 19, according to a predetermined needle stitch cycle. The needle stitch cycle is each time refined by the run of the respective groove bottom in the circumferential direction of the drums 28 and 29 respectively. FIGS. 5 and 6 illustrate two examples out of many possibilities. FIG. 5 shows the groove for producing a simple zigzag stitch, as diagrammatically represented in FIG. 7, while FIG. 6 shows a groove for producing a zigzag-shaped lock stitch, also referred to as serpentine stitch. FIG. 8 diagrammatically shows such a seam. It is understood that by suitable design of the groove bottom the needle bar 15 may be controlled laterally in any desired Way, making however sure that the needle bar each time makes the lateral movement when in raised position and the needle has not yet pierced the cloth to be worked. All types of decorative stitches may be carried out, in which the over-stitch width of the resulting zigzag seam is changed and/or the centre line thereof displaced to the left or right of a normal line.

Changing-over from one needle stitch cycle to another takes place by means of the knob 38 which is at first turned counterclockwise (FIG. 1) which causes the feelers 36 and 37 to swing out from the range of the control drums 28 and 29, whereupon the axle 22 is displaced endwise until one of the feelers 36 and 37 is opposite the desired control groove. Then one releases the knob 38, whereupon the spring 40 brings the respective feeler into engagement with the selected groove.

For indicating the needle stitch cycle each time switched-on, the sewing machine is provided with the following devices. Arranged round the axle 22 are several electric signal lamps 45 sunk in a fixture 46 as shown in FIG. 4. The number of lamps 45 agrees with the number of control grooves 30 and 31 provided in the drums 28 and 29. The fixture 46 is inserted in an opening of the standard and possesses a central aperture 47 through which the axle 22 passes. The screw caps of all lamps 45 are via fixture 46 in electric connection with the standard 10. The centre contacts at the rear end of which elements are fixed to an insulating plate 49. In front of each signal lamp 45 there is a translucent disk or indicating element 50, say; of frosted or artificial glass having indicated thereon the needle stitch cycle associated with the respective lamp 45, as shown for instance in FIGS. 7 to 9. The disks 50 are retained by a cover plate 51 which is connected to the fixture 46 in a way not shown and has window-like openings 52 behind which there are the disks 50. The signal lamps could also occupy a position with respect to each other and to the standard 10, different from that described and recognizable in FIG. 1.

a flexible conductor to one pole of a source of electric power (not shown), the other pole being joined to the standard 10.

f If one of the feelers 36 and 37 engages a control groove '30 or 31, the contact spring 56 touches one of the stationary contact elements 57, thus closing the circuit of the associated signal lamp, this indicating by its lighting up which of the needle stitch cycles is switched-on. The contact springs 56 will then remain also in contact with the contact elements 57, when the feelers 36 and 37 are brought out of engagement with the grooves 30 and 31. Upon displacement of the axle 22 the lamps 45 will therefore light up successively so that one immediately sees when the feeler 36 or 37 comes opposite the desired control groove 30 or 31, i.e. when the knob 38 can be released for switching-in the desired needle stitch cycle.

It is understood that instead of two control drums 28 and 29, the sewing machine could have only a single one. Alternatively both drums 28 and 29 could be axially arranged closely adjacent each other, in which case only a single feeler would be required.

' Further, the machine could include means (not shown and not disclosed) adapted to manually control theoverthe lamps 45, however, each touch a contact element 48,

4 stitch width of the zigzag stitches. To that effect, the lever 21 could for instance be provided with an elongated slot in the manner of a slotted link, wherein the pivot 20 would be adjustable by means of a pertinent sliding block so that the distance of the pivot 20 from the axle 22 could be changed at will.

The sewing machine includes moreover a device known per se and therefore not disclosed in more detail for varying the stitch distance, also called stitch length. This device acts upon the feed dog provided within the free work-supporting arm 60 of the machine and comprises a manually operable setting lever 61 by which the stitch distance may be varied and the feed dog reversed.

In a way similar to the means described for automatic zigzag control of the needle bar, control members could as well be provided to automatically act upon the feed dog mechanism to bring about a change of the stitch distance according to a predetermined cycle. The particular cycle could also be adapted for changing-over possibly with the help of the same knob 38 serving in addition to change-over the zigzag attachment, or with the help of a second setting member.

Alternatively, instead of control drums 28 and 29, other control members could be provided for the same purpose. Some examples are set forth hereinafter with reference to FIGS. 10 to 12.

FIG. 10 again shows part of the link 19 for causing the needle bar 15 to deflect laterally. Said link is joined by a pivot 20 to an oscillating lever 21:: rigidly mounted for rocking with the axle 22a supported for endwise displacement, whereas the lever 21a itself is secured against corresponding axial displacement in a similar way as in the first form of embodiment. The axle 22a carries a lever-like feeler member 70 of magnetically non-conducting material, say, light metal. Inserted in the feeler '70 is a small permanent magnet 71 projecting at one side thereof, while said feeler has a stop 72 projecting in opposite direction. The lever 21a is engaged by one end of a tension spring 73, the other end of which is anchored to the standard of the machine in a way not shown. Said spring 73 tends to swing the feeler lever *70of FIG. 10 to the left until the stop 72 comes against of magnetically non-conducting material, say, synthetic resin, and several cams 77 of magnetically conducting material, such as soft iron, inserted in the periphery of the drum. The cams 77 are arranged in several adjacent rows circumferentially of the drum 76, each of said rows corresponding to a needle stitch cycle, similar to the control grooves 30 and 31 of the first embodiment. Upon endwise displacement of the axle 22a, the feeler member 70 may be selectively aligned with any of the peripheral rows of cams 77 to set the desired needle stitch cycle. The cam-drum 74 serving as counterstop is of the same axial length as the drum 76. The earns 78 of drum 74 could extend over the whole length of the respective drum, but could also be provided as separate for each row of-cams 77.

The action of the aforedescribed device is as follows: If upon rotation of the shaft 27 having the control drum 76 firmly mounted thereon, one of the cams 77 approaches the magnet 71, the feeler lever 70, FIG. 10, will be caused to swing to the right by magnetic pull until the magnet 71 is seated on the respective cam 77 as shown in FIG. 10. Incidentally the needle bar of the sewing machine is deflected to the right by means of the link 19. 'As soon as the cam 77 comes out of the range of the magnet 71 upon continued rotation of the drum 76, the feeler lever 70 is by action of spring 73 swung back towards the stop drum 74 as far as same or its cam 78 will permit, The needle bar is thus caused to deflect to the left. When the next cam 77 of the control drum 76 enters the range of the magnet 71, the feeler lever 70 is again deflected to the right, FIG. 10, under the influence of the magnet. Depending on the transmission ratio between the main shaft 11 and the control shaft 27, an ordinary zigzag seam as in FIG. 7 or a lock stitch running zigzag as in FIG. 8 may in this way be produced.

From FIG. 10 it can be seen that the faces of the cams 77 are at difierent distances from the axis of rotation of the control drum 76, it being thereby achieved that the overstitch width of the resulting zigzag seam will be changed accordingly. In this way it is therefore possible to produce decorative stitches. If the counterstop 74 remains unchanged, the needle bar will each time be deflected only to one side to a varying extent. But there will be a possibility to allow also the cam drum, doing duty as counterstop, to rotate on its axle 75, and in fact at the same or another speed as the control shaft 27. According to the momentary position and height of the stop cams 78 the position of rest of the feeler lever 70 will be changed, which it tends to assume under the action of spring 73, and consequently also the deflection to the left of the needle bar.

For changing-over to another needle stitch cycle, the feeler lever 70 with its magnet 71 is aligned to another cam row of the control drum 76. In order also to permit of sewing straight =lock stitches, the feeler lever 70 may in addition be brought into a position in which no cam 77 of the control drum is facing it, so that, on rotation of the latter, the feeler lever will never be deflected to the right in FIG. 10. The needle stitch cycle set at the time is optically indicated by means similar to those in the first embodiment, whereby a movable contact spring cooperating with a row of stationary contact elements is connected to the feeler lever 70 in a way not shown.

In a modified form, instead of a permanent magnet 71, an electromagnet could be provided. In another modification, the cams 77 of the control drum 76 could be designed as permanent magnets, while the feeler lever 70 could consist of soft iron, or include a soft iron block.

According to FIG. 12, the sewing machine is again provided with a link 19 for the lateral movement of the needle bar. Said link is connected through a pivot 20 to an oscillating lever 21b which, by means of an axle 80, is pivotally supported within the standard (not shown in this case). The lever 21b includes two extensions 81 and 82 adapted to serve as stops, which, in cooperation with the counterstops 83 and 84, limit the oscillation of the lever 21b to either side. According to FIG. 12, both counterstops 83 and 84 are designed as rotary cam disks which, however, is not necessary in every case. Pivoted to the pin 20 is moreover a plunger armature 85 of an electromagnet 86 which when energized causes the lever 21b, FIG. 12, to deflect to the right towards a stop 84. One end of a tension spring 87 engages lever 21b, while the other end is anchored to the standard, in a way not shown. The spring 87 tends to deflect the lever 21b, FIG. 12, to the left towards the stop 83.

In the circuit (not shown in detail) of the electromagnet 86 there lies a switch contact formed by two contact springs 90 and 91 shown in FIG. 11. These contact springs are insulated with respect to each other and a holding ring 92, and located on an axle 93 which is supported angularly and endwise displaceable within the standard and operable by an exteriorly mounted setting member, in a similar way as the axle 22 with knob 38 in the first example. In the unloaded condition of said springs 90 and 91, the respective switch contact is open. One contact spring 90 carries an insulating cam 94 which, by action of the elasticity of spring 90, is urged on and contacts the periphery of a control drum 96 having cams 95. Said drum is rotatable by means of a shaft 27 controlled in dependence on the main shaft of the sewing machine. The cams are arranged on the drum 96 in several longitudinal rows, each of which corresponds to a definite needle stitch cycle. By suitably setting the axle 93, the switch contacts 90, 91 may selectively be brought into the range of one cam row or another. The contact spring 56 serving to optically indicate the needle stitch cycle set each time and which cooperates with a series of stationary contact elements (not shown), is attached to the ring 92, and is insulated therefrom.

The action of the last described control device is as follows: On rotation of the shaft 27 the contacts 90, 91 will be closed each time a cam 95 of the control drum 96 contacts the insulated cam 94. As soon as the contacts 90, 91 are closed, the magnet 86 becomes energized, thus causing the lever 21b to move towards the stop 84 against the action of spring 87, the needle bar of the machine being deflected to the right by means of the link 19. When the related control cam 95 slides otf the insulated cam 94, the contacts 90, 91 open and the magnet 86 becomes de-energized, whereupon the spring 87 causes the lever 21b, FIG. 12, to move to the left towards the stop 83. The needle bar thereby performs a left-hand deflection. The next control cam 95, by closing the contacts 90, 91, again brings the needle bar to the right, and so on. A zigzag seam will thus result. By suitably arranging the control cams 95 in groups within the respective circumferential row, decorative stitches of a Wide variety may be obtained. In the separate circumferential rows of the control drums 96, the cams 95 are arranged in a different manner and number, in accordance with the desired needle stitch cycles.

By suitable angular displacement of the cam. disks 83 and 84 serving as counterstops, the overstitch width of the resulting zigzag seam may be changed and the centre line of the zigzag seam be displaced to the left or right. The cam disks 83 and 84 may be set by hand. It is also conceivable to have the axles of the cam disks 83 and 84 driven automatically at a definite speed ratio to the shaft 27. The cam disks 83 and 84 may be exchangeable or, instead of them, suitable cam drums may be provided adapted to selectively bring into action different circumferential rows of stop cams.

If in the example of embodiment shown in FIG. 10 there is an electromagnet instead of a permanent magnet 71, an arrangement according to FIG. 11 may in addition be used to control energizing and de-energizing of the electromagnet according to a predetermined cycle controlled by the drum 96. The switch contacts 90, 91 then lie in the circuit of said electromagnet.

Similarly the control devices shown in FIGS. 10 to 12 could also be employed to automatically vary the stitch distance, i.e. for controlling the feed dog.

What I claim is:

1. Sewing machine with zigzag attachment comprising a casing, a needle bar, a guide member pivotally mounted in the casing to guide the needle bar, a link connected to the guide member, an oscillating lever mounted on an axle and pivotally connected to the link, a plurality of illustrative indicating elements on the casing corresponding to specific stitch cycles to be carried out by the needle bar, a control member connected to cooperate with the lever and having a plurality of grooves therein, and a single setting knob slidably mounted on the housing connected directly to the axle and operatively connected to the control member to set the needle stitch cycle to operate the guide member by the link and oscillating lever from one of said grooves in the control member, means responsive to the movement of the knob for selecting the specific illustrative indicating element corresponding to the specific needle cycle determined by the control member.

2. Sewing machine according to claim 1 in which said responsive means includes contact means including a. row

of contact elements mounted on the casing and insulated therefrom and from each other, a movable contact element operatively associated with said row of contact elements, means operatively connecting said indicating elements to said row of contacts and said movable contact element, said setting knob with its axle being coupled to the movable contact element so that by axial movement of the knob and axle the movable contact element may slide over the row of contact elements.

References Cited in the file of this patent UNITED STATES PATENTS Qmel Apr. 22, 1947 Johnson Dec. 2, 1958 FOREIGN PATENTS Great Britain Sept. 12, 1908 France Dec. 29, 1954

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