US1958207A - Means for making hemstitched seams and the like - Google Patents

Description

May 8, 1934- K. G. scHElBEL ET AL 1,958,207

V MEANS FOR MAKING' HEMSTITCHED SEAMS AND THE LIKE I Fild ont. 21. 1932 45mm-sheet 1 Hull-IN milling-wlw m Munn ATTORNEY lll.

May 8, 1934. K. G. scHElBEl.. Er AL MEANS FOR MAKING HEMSTITCHED SEAMS AND THE LIKE V Filed Oc. 21. 1932 4 Sheets-Sheet 2 l/////// vllllmlllllll ,v Q 311144274 50' Z4 25 g W ATTORNEY Y K. G. scHl-:IBEL Er AL 1,958,207 I May 8, 19321.

MEANS FOR MAKING HEMSTITCHED SEAMS AND THE LIKE 4 Sheets-SheenJ 5 Filed oet. 21, y1932 2l v 'I @12p ATTORNEY May 8, 1934. K. G. scHElBl-:L Er AL 1,958,207

MEANS FOR MAKING HENSTITCHED SEAMS AND `THE! LIKE Filed Oct. 21, 1932 4 Sheets-Spee?. 4

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my why JVNVENTOR: ,4H/mf una ATTQRNEY Patented May S, 1934 MEANS FOR MAKING HEMSTITCHED SEAMS AND THE LIKE Kur't Gustav scheibe and Arthur Albrecht Behmann, Dresden, Germany, assignors to Wrker, G. m. b. H., Stickautmatenfabrik, Dresden,

GermanyA Application Uctober 21, 1932, Serial No. 638,870 in Germany November 19,1931

z claims. (ci. 11a-160) The present invention relates to improvements in or relating' to apparatus for making hemstitched seams in fabrics.

It is an object of the present invention to provide a method by which a hem-stitched seam can be produced on zig-zag sewing machines and also by means of a device on household sewing machines whereby the holes are enlarged by means of a coarse needle and then stitched by means of the same needle in various directions of stitching. In this way the enlarged holes are bound together a number of times. By means of this method triangular as well as quadranglllar hem-stitches can be produced on household sewing machines with Zig-zag devices and also by means of a device which is operated by the needie-rod so that the housewife is able to sew hemstitches into linen without the aid of a special machine. These hem-stitched seams can be stitched into any kind of material and have the particular advantage that the seam can be cut along the edge (picot edging) whereby collars and volants and so forth for clothes can be produced having pointed edges. Also, this method of stitching enables hem-stitches to be made in stockinette which was not possible hitherto with the special machine which operated by means of piercers, because the piercers tore the stitches of .the fabric. By means of the new method of stitch formation, however, the stitches of the fabric are merely forced apart and the stitches are drawn together by the multiple binding.

Turned up seams can also be produced with this hem-stitch seam whereby the rear side can be neatly cut out on account of the peculiarity of the seam. This formation of seam is made extremely strong on account of the multiple binding and if a thread of another colour is used for the StitchingV a particularly beautiful ornamental hem-stitch is produced.

' The main feature of the method according to' this invention resides in the fact thatthe hole without further movement of the material in the direction of stitching. 'I'his is most impor- V tant for the perfection and uniformity of the seam because during this stitching processthe materialremains under tension. The material feeder of the sewing machine or that of the attachment can then be formed as a frame which prevents the material from drawing together when the coarse needle pierces it.

It is of the greatest importance for the production of hem-stitched seams by means of an attachment for sewing machines that the attachment should be kept as small as possible. The attachment must not only elfect the displacement' of the material in different directions but it must also effect the feeding of the material in the direction of sewing. A small construction is attained according to the present invention in that the component movements of the material feeder are brought about by means of two curves which operate either alternately or simultaneously to control the material feeder to move in dierent directions, the control means operating on the feeder being coupled together. By the aid of two curves a large range of patterns is attained so that there is no limitation to any particular hem-stiched seam.

For working with particularly strong materials the device, however, can also be provided with a piercer which pierces in advance of the needle and is secured to a lever. The hole which has been pierced by means of the piercer is then drawn apart by the various more or less radiating stitches produced by the device and sewn roundhwhereby the stitches which lie in the direction of sewing connect also with the subsequent holes.

It is of'importance in forming stitches that the last stitch of the stitch formation of one pattern repeat shall lie at the correct angle to the first stitch of the following pattern repeat.

In order that the invention may be well understood reference will be made to the accompanying drawings in which:-

Figure 1 isan end elevation in section of theI feeder and stitching needle in which the feeder moves back and -forth in the direction of stitching and the yneedle swings out transversely to the direction of stitching to left and right,

Figure 2 is alplan of the feeder,

Figure 3 is an end elevation in section of Aa feeder with anv up' and down moving needle which is not displaceable laterally the feeder be'- ing arranged to move not only back and forth in y the direction of stitching but also transversely to the direction of stitching to left and right,

FigureA 4 is a plan ofthe feeder shown in Figure 3, L Figure 5I shows the sequence and course of the thread of the individual stitches for a. trlangular hein stitch,

Figure 6 shows two curve diagrams for displacements in two directions.

Figure 7 shows the position of the thread for a quadrangular hem stitch in which the last stitch runs diagonally,

Figure 8 shows two curve diagrams for displacements in two directions,

Figure 9 shows the sequence and path of the thread of the individual stitches for a quadrangular hem stitch without a diagonal stitch,

Figure 10 shows two curve diagrams for displacements in two directions,

Figure 11 shows diagrammatcally the stitch arrangement for a drawn thread, bound single needle hem stitch,

Figure 12 shows diagrammatically a drawn ground effect,

Figure 13 is a side elevation partly broken away and partly in section of a preferred form of device for sewing machines,

Figure 14 is an end elevation in section of the device shown in Figure 13,

Figure 15 is a side elevation of this device,

Figure 16 is an'end elevation of the -mechanism for driving the feeder by means of a plane curve,

Figure 17 shows the prismatic means for securing the device on the material presser rod,

Figure 18 is a plan in section,

Figure 19 is an underneath plan view,

Figure 20 is a side elevation of the device in which the lifting device carries a piercer,

Figure 21 is a -diagrammatic elevation of a pusher lifting device controlled by intermediate levers,

Figures 22 to 24 show diagrammatically different stitch arrangements for sewing round the holes which have been pierced,

' tion of sewing (Figures 1 and 2).

In order to produce hem-stitched seams on these machines, the fine needle a is exchanged for a strong needle and the needle-rod is driven by a control curve or cam which has a particular curve inclination corresponding to the Diagram I (Figure 6) for a triangular hem stitch and has a curve inclination corresponding to Diagram I (Figures 10 and 8) for a quadrangular hem stitch. The material feeder b is likewise moved back and forth by means of a special/control curve or cam, the curve inclination of which is designed according to Diagram II (Figure 6) for a. triangular hem stitch and accordingY to Diagram 1I (Figures 10 and 8) for a quadrangular hem stitch. The material feeder as well as the needle rod can be driven by means of a known control means from the curve or cams.

The movements of the material feeder and of the needle rod take place in the following sequence for making triangular hollow seams:-

The needle rod makes one stitch (stitch 1) the material feeder feeds the material by one stitch length to the second stitch (stitch 2), moves the material back again to the ilrst stitchA (stitch 3) and again back to the second stitch (stitch 4). Now the material feeder feeds the material backward through one half stitch length whilst the needle swings out by the width of one stitch (stitch 5), the material feeder brings the material again forward, the needle rod goes back into its initial, position to the second -stitch (stitch 6), both parts then swing back again to the fifth stitch (stitch 7), and the pattern repeat of the seam is completed. The material feeder then goes under the'needle plate and swings idly backwithout moving the material and after rising again feeds the material forward by a completestitch length, and theY needle rod remains swung out for the eighth stitch (stitch 8). The material feeder then brings the material forward again to the fifth stitch (stitch 9) and back again to the eighth stitch (stitch 10). Then the needle rod swings back again into its initial position and at the vsame time the material feeder moves the material back by one half stitch length to the second stitch (stitch 11) moves it forward again to the eighth stitch (stitch 12) and back again to the second stitch (stitch 13), so that the second pattern repeat which is the mirror image of the 'first is completed and the material feeder now moves idly under the needle plate for the next pattern repeat and so forth. The last stitch of the second pattern repeat is therefore the same as the first stitch of the rst pattern repeat.

'I'he movements of the material feeder and of theneedle rod for a quadrangular hem stitch are as follows:-

The needle rod makes one stitch (stitch 1), the material feeder feeds the aterial through one stitch length to the second stitch (stitch 2), leads the material again forward to the first stitch (stitch 3) and back again to the second stitch (stitch 4). Now the needle rod swings sideways by thewidth of one stitch to the vfifth stitch (stitch 5), back again to the second stitch (stitch 6) and back again to the fifth stitch (stitch 7) The needle rod remains in its displaced position and the material feeder feeds the material by one stitch length forward to the eighth stitch, (stitch 8) brings it back again to the fifth stitch (stitch 9) 'and again forward to the eighth stitch (stitch 10) and back again to the fifth stitch (stitch 11). The needle rod swings back into its initial position to the second stitch (stitch 12) This last stitch is the same as the first stitch of the new pattern repeat. The material feeder then passes under the needle plate and swings idly Without feeding the material in the direction of sewing forward and.after rising again feeds the material again by a complete stitch length in the direction of sewing to the second stitch and so forth.

It is in general possible. for example, for triangular hem stitches to select the time sequence in another manner and indeed the material feeder need not move the material in the sewing direction alternately one after the other back and :loov

forth by a complete stitch length and then to..

execute the oblique stitch together with the swinging outv of the needle rod, but the sequence can be so selected that the straight stitch and the oblique stitch follow one another alternately until the stitch holes which are arranged in a triangle are bound on three sides by means of three threads. The sequence can also be such that the chosen in a different manner and at the same time produce the same effect of the hem stitched seam. The operation in Figure 5 corresponds to the combination of both repeats and the dotted lines represent in each case the idle passage of the material feeder under the needle plate without taking the material with it.

Obviously it is also possible to allow the needle a to swing out in the direction of sewing, in which case the material feeder b` must be moved transversely to the direction of sewing. In the case of a triangular hem stitch this has the advantage that the lighter needle rod must sew the large as well as the half-size stitches in the stitching direction, whilst the material feeder would be interrupted during the large stitches in the sewing direction. It is thereby possible to increase the speed of the machine.

Household machines, however, are known according to German patent specifications No. 484,439 and No. 541,661 in which the material feeder c is moved in the sewing direction as well also as transversely thereto (Figures 3 and 4).

Referring to these gures, the special-needle plate d which is driven by the material feeder c is taken with the latter upon transverse movement thereof. The needle plate d in known manner is guided in a special plate e provided with slots.

In order to produce hem stitched seams on these machines the material feeder must be moved back and forth and also transversely to left and right corresponding to the direction of the arrow in Figure 4. The displacement of the material feeder can likewise be effected by means of two curves or cams and in fact for triangular hem stitched seams and cuadrangular hem stitched seams, the forward and backward movement of the material feeder can be effected by the curve II and the transverse movementof the material feeder can be effected by means of the curve I (Figures 6, 10 and 8).

The sequence of operation for the triangular hem stitch is -as follows:-

The needle makes one stitch (stitch 1) the material feeder of the sewing machine which is also movable transversely of the direction of sewing feeds the material by one stitch length tothe second stitch (stitch 2), feeds the material back again to the rst stitch (-stitch 3) and backwards again to thesecond stitch (stitch 4). The material feeder then moves the material backwards by one half stitch length and at the same time moves it by one stitch width sideways to the fth stitch (stitch 5). Ihe feeder then brings the material back again to the secondstitch (stitch 6) and backwards again to the fifth stitch (stitch 7). and the pattern vrepeat of the seam is completed. The feeder then passes under the needle plate/swings idly back retaining its transverse movement. After rising it moves the material by a complete stitch length in the sewing direcftion forward to the eighth stitch (stitch 8), brings the material again forward to the fifth stitch (stitch 9) and backwards again to the eighth stitch stitch 10). The feeder then moves the material by one half stitch length and is simultaneously moved by one stitch width trans--v versely of the sewing direction back into its initial position to the second stitch and so produces an oblique stitch (stitch 11). It then swings forward again to the eighth stitch (stitch 12) and backwards again to the 'second stitch (stitch 13) whereby the second pattern repeat which is th'e mirror image of the rst is completed and the feeder has only to swing idly under the needle plate to the new pattern repeat and so forth. The last stitch of the second pattern repeat is in this manner the same as the first stitch of the rst pattern repeat.

The seduence of operation for the quadrangular hem stitch by means of this device is as follows The needle makes one stitch (stitch l) 'the feeder of the sewing machine which, as aforesaid, is movable transversely of the sewing direction moves the material by one stitch length to the second stitch (stitch 2) moves the material forwards again to the rst stitch (stitch 3) and back again to the second sitch (switch 4). The feeder then moves the material transversely to the sew'- ing direction by one stitch width to the fth stitch (stitch 5) vback again to the second stitch (stitch 6) back to the fth stitch (stitch 7), the feeder remains swung out transversely of the sewing direction and moves the material in the sewing direction forward by one stitch length to the eighth stitch (stitch 8) back again to the fth stitch (stitch 9) yand forward to the eighth stitch (stitch 10) 'and again backwards to the fifth stitch (stitch 1l) .Y Then the material feeder goes transversely of the sewing direction back into its initial position and moves the material to the second stitch (stitch l2). This last stitch is identical with the first stitchof the new pattern repeat, the feeder then passes under the needle plate and swings idly without moving the material in the sewing direction forwards and after rising again moves the material again by a complete stitch length in the sewing direction to the second stitch and so forth.

- A particularly effective cuadrangular hem st'tched seam "s also obtained if the last stitch 0f the hem stitch forms the diagonal of the quadrangle as is to be seen from Figures 7 and 8, but of course the secuence of operation must be arranged diierently. The arrangement is quite clear from these figures so that further and more detailed description is unnecessary. This arrangement of the stitches, however, has also the advantage that with a single device triangular as well as cuadrangular hem stitches can be sewn by merely changing the curve or cam, because both these stitch formations have the same divisions. It is of importance for the effectiveness of the seam that two adjacent stitch holes shall be bound by at least three threads. If. for example, the binding was effected by only one thread the hem stitch would not have a very good appearance 'ind again. in the first place the needle would only pass through the same stitch hole a few times and would force the material apart to too slight an extent and in the second place the stitch hole would be insufficiently hound so that ends of material would remain. These ends result from the fact that when the needle pierces the fabric a warp or a weft thread is frequently pierced and torn. These torn threads cannot be completely bound in by a single length of thread. Apart from that. however, by reason of the unequal number of the threads it is possible to produce a progressive seam because the starting point of the first stitch and the end point of the last stitch are separated by the size of one stitch.

The method of producing hem stitched seams described. however. can also be carried out by means of. attachments for sewing machines which are operated b v movement of the needle rod.

. Thus, the curves may be connected together to a 2 I with its wave-form depressions transmits its l common drum-like body which can be exchanged withvvery little manipulation for another drum-- like body. Since the curves possess contours and steps corresponding to 'different patterns the range of patterns of the fancy stitch device is very great. Great accuracy in sewing is obtained especally by reason of the fact that the pattern is sewn in a single operation conforming to the repeat. Only after completion of the repeat is the material moved forward by means of al special feeder or else by the same feeder, the movement being preceded by an idle movement of this feeder by the amount of the material feeding movement in the sewing direction. This forward movement is made possible in that a lift lever, controlled by cams presses down on the material, holds this fast and at the same time lifts the whole device with the material presser rod a little 'so that the material feeder passes idly over the materia! which is retained in position. f

The construction and method of operation of the device are more fully described in the following. The U-shapedhousing 3 of the device is mounted by means of a prismatic angle member 4 on the material presser rod 1 of the sewing machine 2. The angle member 4 is firmly secured to the housing 3 of the device by means of screws 5 and is interchangeable to suit diiferent sewing machines. A forked ratchet lever 9 is moved up and down by the needle rod 6 by means of a cylindrical boss 7 on the needle holder 8 and sets in intermittent rotation a spindle 11 by means of a pawl and ratchet gear 10 of known form per se. A brake spring 12 of known form is secured to one end of the spindle 11 by means of a screw to prevent return of the spindle 11 upon return of the ratchet lever 9. The spindle 11 is providedin its middle portion with two keys 13 so that it will carry with it a drum member mounted thereon. The drum member consists essentially of a cam I for the horizontal movement and a cam II for the vertical movement. Both cams are connected securely together with interposition of distance pieces 14 and 15v by means of axial bolts 16. The cams carry ron their side faces step-like depressions which are graduated according'to the pattern in` the ratios of 2:10 8:6 and 4:8, that is to say the cams possess large and small steps which are separated by uniform parts of the cams. The steps can alsobe twice as 4large in one direction but it is necessary that the actual ends of the curve close on one another after a complete rotation of the drum member, that is to say the repeat of a pattern must be destributed periodically over one rotation. There is therefore a relation of the individual sections of the curve to the whole curve .gradua-v tion which stand in relation to one another according to the principle upon which the device is to work as will be hereinafter explained. The cam movement to a two armed oscillating lever 17 which bears with it a projection 18 against one side of the camV I whilst on the other side an adpin 31 and on the other hand by that of the pin justing screw 19 is mounted in the rolled over portion 20 of the lever 17. By means of the adjusting screw 19 the oscillating lever can bear against the sides of the cam I with more=or less play. In this manner an adjustment of the stroke is attained. I'he lever 17 is pivoted about the bearing pin 21 which is secured against the floor of the housing 23 of the device by means of a nut 22. 0n the other end is a guide pin 24 about which a guide block 25 is rotatably mounted. The guide block engages in a^groove 26 of the material feeder carrier 27. The feeder carrier is provided with two upstanding arms 28, between which a closed v frame-like plate 29 serving as a material feeder is suspended about a hinged pin 30. The underside of the frame like plate 29 is provided with grooves or other roughened surface so that it will take with it the material. On the other end a bearing pin 31 is guided in the material feeder carrier 27 and is secured to one arm of a bell crank lever 32 by means of nuts 33. The bearing pin 31 extends through a slot 34 in the bottom of the housing. The feeder 36 as well as the os-v cillatlng lever 77 liesv co-axially with the pins 21, 24 and 31 in the direction of sewing, the lever 17 and the material feeder carrier 27 being arranged to have the -bottom of the housing of the device between them. The material feeder carrier 27 is guided on the one hand by the shank of the 24. The bell crank lever 32 oscillates about a pivot pin 35 and is driven by the cam II lfor the vertical movement in the same manner as the lever 17. Both cams therefore possess wave form depressions or indentations corresponding to the .no

pattern and are mounted upon a common spindle 11, only the vertical movement is transmitted through the bell crank lever 32 so as to change the direction of motion. This change of direction,

is moved back and forth by displacement member 36 in the direction of sewing. The feeder is therefore guided on the one hand by the bearing pin 31 which projects through the bottom of the housing of the device and on the othbrhand by the pin 38 which is secured to one sideowall of the housing. The displacement member 36 is provided with a fixed projection 39 on one side and with an adjusting screw 40 on the other side; these two partsengage the periphery of the cam'III.

The central distance piece 15 carries cam pro. jections 41 which are distributed according to the pattern in the ratio 1:2, 1:3, 1:4,'1:6, or 1:12 of the cam divisions. According to the kind of pattern therefore there may be 1, 2, 3, 4 or 6 cam projections distributed around the distance piece 15. The cam projections 41 operate a bell crank lift lever 42 which swings about a pin 43 fixed in the side wall of the housing. The head of the bell crank lever .likewise possesses an adjusting screw 44 so that the magnitude ofthe swinging movement can be adjusted. At the other end the lift lever is'forked and embraces the needle 45. If the lift lever is swung out by the cam proiection 41 the forked end presses on the material and lifts the whole device with the material presser rod a little. If how the material feeder carrier 27 is moved it passes idly with the plate 29 over the material and is only brought again into engagement with the material when the cam proiectlon 41 has released the lift lever 42 and when 150 Lesage? the device has dropped again. By means of the co-operation of the lift lever 42 with the material feeder 27 the material' can be progressively moved in the direction'of sewing. If, for example the material feeder carrier is moved by the cam to follow a denite pattern repeat back and forth or sideways and obliquely then after the completion of the stitched repeat the lift lever comes into operation and raises the device. At the same instant the material feeder goes forward where, upon releasing the lift lever it again comes in contact with the material and upon returning feeds on the material in the direction of sewing by a certain amount. Upon the idle forward movement of the material feeder which is operated from the upward movement of the needle rod, the material naturally remains stationary and the needle penetrates again idly into the same hole and so produces a knotted stitch; this knotted stitch may be advantageous for various patterns. This knotted stitch or the empty passage of the material feeder can be avoided if the lift lever 42 simultaneously effects Athe feeding movement of the material in the direction 'of sewing. In this manner a progressive movement of the material is obtained. The lift lever can also be formed as a single-armed lever but it is important that the operated lever in both cases directly engages with the material. In sewing curves it is important that the material can be.

easily rotated under the material feeder of the device. It is therefore advisable that the lift lever should narrowly encompass the needle and be arranged within the closed frame-like plate for the feeding of the material.

In Figures 5 to 12V a few of the many diagrams of stitch formation are illustrated by way of example. In the patterns according to Figure 5 the feeding movement of the material in the direction of sewing is effected by the material feeder carrier 27, which however, also moves the material for the individual stitches of the repeat. In this case the dotted lines f indicate the idle forward movement of the material feeder carrier 27. At that instant the material remains stationary whilst the needle penetrates again into the stitch hole and executes a knot stitch. This knot stitch is, however, not in any way disadvantageous for the formation of the seam because it is taken up by the subsequent stitches.

In Figure 11 is shown a diagram for a bound single needle hem stitch which can likewise be produced with the device and the threads are drawn together in sewing in known manner. It is characteristic in the case of this seam that the two stitchings 4 and 5 must be sewn by means of double as large steps of the vertical cam II. Whilst the vertical cams of Figures 7 and 9 merely show simple steps of equal size with straight intermediate portions, the cam II of Figurev is divided into large and small steps whereby with the small step on the horizontal curve I likewise curve portions are effected, which upon simultaneous working of the curve produce oblique stitches. A good combination can be seen from Figure 12.

Obviously there are still further possibilities of stitch formation which can be produced by interchanging the drum members with the two cams I and 1I.

It is to be observed that with the device described it is also possible to stitch a hem stitch which only has one hole as is produced-on special machines. Such seams, however, cannot be produced with a strong needle. Even with a weak needleand when the stitch formation is such that a hole is drawn apart by radiating stitches, the hole is not suiciently big to give the effect of a hem stitch. j Consequently, it is necessary to make in the material a suiciently large hole by means of a piercer, the hole being drawn apart by means of diierent 4stitches in a more orless radiating form and sewn around the stitches lying in the direction of sewing connecting up with the succeeding hole. It is true that already ornamental siitch devices are known which operate with a specially controlled piercer. In the present invention, however, the piercer is arranged in combination with the lifting means which hold the material iixed and at the same time lift the device. This has the advantage that a special control means is not required. The lifting means formed as a lever or like' a feeder then comes in operation if and when the material feeder ls to pass idly over the material, in order to bring up fresh material in the direction of sewing.

It is essential that the piercer precedes the lift movement upon striking and follows it upon 'sinking of the device so that the material is always held firm by the material feeder not only upon piercing but also when, the piercer rises. The whole piercer assembly must be arranged in a small space and a further example is given to show how the piercer makes a hole ahead of the needle and is secured to a lever the piercer being formed in an arcuate form to correspond with the movement of the lever. In this arrangement the piercer precedes the needle rod and nevertheless pierces the next following hole to be struck.

Thedevice 3 is secured in known manner to the prismatic portion of the material presser rod 1 of the sewing machine 2. g

The spindle l1 of the device is likewise set in known manner into intermittent rotary motion 11'5 by means of a known ratchet gear from the needle rod 6. Cam projections 41 are rigidly connected with the spindle 11 and are distributedone or more times round the periphery of the distance piece 15 according to the stitch formation for the 120 pattern repeat.

An angular, or bell crank lift lever 42 oscillates about the pivot pin 43 and is provided at its head with an adjusting screw 44 whereby the magnitude of its oscillation which iseifected by means of the cam projections 41 can be adjusted. A tension spring 60 urges the screw 44 of the lift lever 42 against the distance piece '15. At its other end the lift lever 42 carries a piercer 61 which can be adjusted in height and secured by means of a screw 62.

The method of operating the device is as followsz-The lift lever 42 is so rotated by means of the cam projection41 that first of all the piercer 6l passes through the material 63 at a certain stitch hole 64. During this the material feeder plate 29 holds the material firmly so that the ma? terial cannot be drawn into the perforated hole 64. Upon further movement of the cam projections 41 the underside 65 of the lift lever is pressed on to the material, the material is held xed and the wholeldevice with the material presser rod 1 is lifted a little. Thereby at the same time the material feeder plate 29 is removed from the material and the material feeder carrier 27 is moved forward idly so that the material feeder plate 29 moves over the material which is held fixed. Then the lift lever 42 is released by the cam projections 41 and by reason of the tension spring 60 it returns to' its original 150 terial feeder plate 29.

The perforated hole in the material is now sewn around in the known manner in different directions. .After the sewing has been completed according to the pattern repeat the lift lever 42 is again set in operation whilst the material feeder plate 29 passes idly over the material and upon backward movement the new material is further moved in the direction of sewing.

In Figure 20 the piercer is -mounted on the lift lever `42. The piercer therefore executes an arcuate movement which, if the centre of rotation is sufllciently far removed and is suitably chosen,

does not present any great disadvantage.

In Figure 2l a further example is given in which the piercer is secured to a push rod 66 which is guided vertically in bearings 67 of the device 3.

'Ihe lift lever 42 engages in the slot 68 of the push rod and is controlled by cam projections 41 in the same manner as is described above. Essentially, however, in this arrangement the arcuate movement of the lift lever 42 is converted into a vertical movement of the push rod 66.

The push rod 86 in Figure 21 as' well as the lift lever 42 in Figure 20 may also carry a plurality of piercers which are so graduated in length with respect to one another that the rst piercer pierces the hole and the second piercer completely enlarges vthe hole. It is important however that the piercer should be arranged in the immediate neighbourhood of the needle 45 of the sewing machine so that curves can also be sewn on this device. In Figure 20 the piercer is arranged immediately in front of the needle 45.

In Figures 22 to 24 various stitch forming operations are diagrammatically illustrated and for the Isake of simplicity round.- enlarged holes 70 are shown.

The small figures show the sequence of the individual stitches and the dotted line I indicates the idle movement ofthe material feed plate 29 over the material which obviously takes place in the same direction of stitching as the stitch 2 and merely for the sake of clearness is indicated obliquely and not as a stitching movement. In Figure 22 two holes are always bound by three stitches, 2, 5, 6.' It is very important for the quality ofy the stitching that the last stitch 8 (Figure 22) should be at the correct angle of stitch formation according to the pattern repeat to the stitch 1 of the next repeat, because the knotted thread always liesat the edge of the hole of the material. If both stitches ran behind one another in one direction then the knotted stitch of the lock stitch would lie in the middle of the hole so that the hem stitch wouldvnot come out clean.

In Figures 22 and 23 the hole'is drawn open in four directions by radiating stitches. Y Figure 24 sshows the diagram of stitch formation in which the hole is sewn around in six directions radiating from the hole. A very beautiful clean seam is produced which does not go together after In the following example a' further construction is ,shown in which push plates are controlled by the cams for moving the material feeder. This arrangement makes possible a very narrow coni struction and also the utilization of several cams.

The device is secured in known manner to the material presser rod of the sewing machine. A number of cam discs 71, 72, 73, 74 are fixed on a spindle 70. The spindle 70 is intermittently moved by means of a ratchet wheel 75 from a ratchet lever 76 through a pawl 77. A slot 78 in the end of the ratchet lever '76 engages with a cylindrical boss 79 on the needle rod 80 and is oscillated by this. In order that the engagement of the pawl 77 with the ratchet wheel 75 may be varied the pawl 77 is rotatably secured to a separate plate 81 by means of bolts 82 so that the plate 81 can be rotated on the ratchet lever 76 about the spindle 70 by means of two screws 83.

-Slots 84 in the plate 81 limit the extent of adjustment. 'I'his adjustment is necessary so that the cams 71, 72,. 73 and 74 can be brouglit into the correct sequence to follow the needle rod stroke vof the sewing machine. The push plate 85 is driven through the agency of a pin 86 by the cam 73 sov that it follows the curvature of the4 cam. The push plate 85 moves in a straight guideway provided by the spindle 70'and the bolt 87. The bolt 87 like the spindle 70 passes 1U) through the whole device and is mounted rotatably in both side walls of the housing. In order that the push plate can be moved, slots 88 are provided for the spindle 70 and slots 89 for the bolt 87. The push plate is provided with an arm 105 guided by a pin 94 which is fixedly connected with the housing and passes through a slot 95. Similarly a push plate 96 is moved by the cam 74 and is likewise guided in a straight line by means of the spindle 70 and the bolt 87 in slots 88 and 115 89. This push plate also has an arm 97-which likewise at the lower end is provided with a slot 98 in which one arm 99 of the bell crank lever engages. The bell crank lever is rotatable about a pin 100 fixed to the housing andl carries on its 120 other arm 101 a pin 103 which is guided in a slot 104 ofthe material feeder. Upon movement of the push plate 96 the bell crank lever is rotated about the pivot pin 100 and thereby moves the material feeder sideways by means of the pin 108, 125 the material feeder swinging about the pin 94 as pivot. The material feeder can1 be swung sideways through the push plate 96 by means of the bell crank lever as well also as backwards and forwards through the push plate 85 by means of'13@ the pin 92. If both push plates are operated from the cams at the same time oblique stitches in any direction can befproduced` The piercer 105 is secured to the lever 106 which oscillates about the pivot pin 107 and is driven from the cam 71 through the pin 108 in such manner that the piercer strikes the material under tension and in the same manner is removed from Ithe hole so that the material can be moved to different sides by the material feeder. LA If Ithe hole is made and the material feeder so moved that the hole as explained in the introduction is enlarged and sewn around, then two levers 109 which lare mounted Vabout pivot pins 110 are swung downwardly by the two cams 71.

Two guide pins 112 are secured to the levers 109 forwards having slots 115 engaging with the two 150 guide pins 112. The material feeder is held together by a common bridgel piece 116. This carries a pin 117 in which a limb 118 of a push plate 119 engages. The push plate 119 is driven by means of the pin 120 from the cam 72 and is guided in a straight line by the spindle 70, the pin 87 and the two-slots 88 and 89. The material feeder is therefore moved backwards and forwards by the push plate 119 Whilst it is oscillated up and down by means of the two levers 1091 On the forward end of the material feeder are two toothed feet 121 'on the two sides of the material feeder 93. If the hole is enlarged and sewn around all ready then the material feeder 114 is swung downwards by the lever 109 the feet lie on the material against the needle plate and raise the whole device about 1-2 millimetres high whereby the material pressure rod 99 which forms a complete whole with the device serves as a guide and the material is moved backwards by onestitch length in the direction of sewing by the feet 121 of the material feeder by means of the push plate 119. Thereupon the material feeder is again moved upwards by the lever 109 and the material is held fast so that a new hole can be perforated and sewn around. In this time the material feeder 114v moves back idly again over the material.

Having now particularly described and ascertained the-nature of our said invention and in what manner the same is to be performed, we declare that what we claim is-' 1. In hemstitching attachments for sewing machines, a material feeder, and alternately operating cams for controlling the movement of said material feeder in diierent directions, a driving spindle on which said cams are interchangeably the cams to operate said bell crank lift lever, and

means to adjust the eld of the swinging movement of said bell crank lift lever, one end of said bell crank lift lever being forked to embrace the needle.

2. In hemstitching attachments for sewing machines, a bell crank lift lever, cam projections to rotate said lift lever, a piercer mounted on said lift lever to pass through the material at a certain stitch hole, a material feeder plate to hold the material rmly during the operation of the piercer to prevent the material from being drawn into the stitch hole, said cam projections operating to press the underside of said lift lever onto the material to hold the same, and lift the attachment, a spring for returning the lift lever to its original position upon release of the same by the cam projections to allow the material again to be engaged by said material feeder plate.

. KURT GUSTAV SCHEIBEL.

ARTHUR ALBRECHT BOHIVIANN.

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