US3461826A

US3461826A - Sewing device with a double chain stitch sewing machine

Info

Publication number: US3461826A
Application number: US706960A
Authority: US
Inventors: Hans Scholl; Alfred Heimann
Original assignee: Kochs Adler AG
Current assignee: Kochs Adler AG; Kochs Adlernahmaschinenwerke AG
Priority date: 1968-02-20
Filing date: 1968-02-20
Publication date: 1969-08-19
Anticipated expiration: 1986-08-19

Description

1969 H. SCHOLL ET-AL 3,461,826

SEWING DEVICE WITH A DOUBLE CHAIN STITCH SEWING MACHINE Filed Feb. 20, 1968 mm H INVENTORS.

flfl/YS 3CHOLL) flLF/QL D HF/MA/ IV I United States Patent 3,461,826 SEWING DEVICE WITH A DOUBLE CHAIN STITCH SEWING MACHINE Hans Scholl, Bielefeld, and Alfred Heimann, Senne, Germany, assignors to Kochs Adlerrlahmaschinen Werke AG, Bielefeld, Germany .9 Filed Feb. 20, 1968, Ser. No. 706,960

Int. Cl. D05b 1/10 US. Cl. 112-121.11 5 Claims ABSTRACT OF THE DISCLOSURE A pattern controlled sewing device having workpiece clamping holders and guide patterns arranged beneath the clamping holders. A double chain stitch sewing machine is provided with a thread carrying needle, a thread carrying looper, a throat plate with an inset pivoted in it and having an oblong stitch hole, and a thread spreader to allow the forming of seams in every feed direction. The inset is controlled by a pattern follower device cooperating with the patterns and in driving connection with the inset through transmitting means in the form of an endless ball string, for rotating the oblong stitch hole in a direction corresponding to the shape of the patterns.

It is a primary object of this invention to provide an automatic sewing device for producing collars, cuffs or workpieces with changing direction of the seam by means of a double chain stitch sewing machine which has a thread carrying needle, a thread carrying looper, a workpiece press pad and a thread spreader, which allow the forming of a seam corresponding to the shape of the pattern used in the sewing device, in order to avoid the replacement of the lower thread bobbin,'which is necessary when using a lockstitch sewing machine after sewing a fixed length of a seam.

It is a further object of this invention to provide a pattern controlled automatic sewing device as described in the United States patent to Hans Scholl No. 3,276,405, dated Oct. 4, 1966. This patent discloses patterns for producing the above described articles and a driven roller or a magnetic roller for the cooperation of the pattern with a double chain stitch sewing machine provided with the above described means.

It is already known to develop double chain stitch sewing machines in such a manner that they sew in every desired direction. For this purpose a circular motion is imparted to the thread spreader above the thread carrying looper. During these motions the thread spreader moves forward with the looper and catches the looper thread, as well as the needle thread loop hanging on the looper between the looper point and the stitch hole. When returning, the thread spreader leading the looper, deflects the looper thread and the needle thread loop in such a manner as to form a thread triangle for the entering of the needle. The joints of the thread triangle are always fixed in the same position by the looper, the thread spreader and the stitch hole, irrespective of the direction and length of the feeding.

Such an arrangement is disclosed in German Patent No. 483,989, patented on Oct. 2, 1925.

As with chainstitch sewing machines, the loop of the needle thread is only tightened at the next entrance of the needle, the stitch hole of these sewing machines being developed in sewing direction as an oblong hole. Such a stitch hole however allows the forming of a seam only in one or two feed directions, even if the sewing machine is equipped with sewing tools, which enable sewing in all directions. In order to be able to sew with the double chainstitch sewing machine in all directions, according to 3,461,826 Patented Aug. 19, 1969 "ice the above mentioned patent, it has been proposed to provide the upper surface of the throat plate around the siitch hole with a hollow. However, this is objectionable, since this fabric is drawn down to the bottom of the stitch hole by the needle while sewing, thus hindering an even tightening of the threads.

In order to overcome this shortcoming, there has been proposed a throat plate having three or more slots formed therein and extending from the stitch hole in star-shaped relation thereto. It should thus be possible to lay down the needle threads in one of these slots, so as to achieve an unobjectionable tightening of the threads, when fixing the stitches. Such an arrangement is disclosed in the US. Patent 3,313,259, issued on Apr. 11, 1967.

However it is possible when feeding the workpiece in certain directions, that the threads will not slip off from the rounded ends of the arms into the slots, thus producing false stitches. The throat plate according to this patent is not suitable for automatic sewing devices in which the workpieces are clamped into clamping holders.

Summary According to the invention, the above problems are solved by providing a throat plate inset pivoted in the throat plate, which is controlled by a pattern-follower device through transmitting means in such a manner that the oblong stitch hole will be aligned according to the shape of the patterns. The pattern follower device consists of a gauge finger secured to a lever which is pivoted on the driving shaft of the roller or magnetic roller and of a torsion spring which presses the gauge finger against the guiding patterns, furthermore of a driving wheel fastened to the lever for transmitting the rotary motions of the gauge finger to the throat plate inset through the transmitting means.

The inset pivoted in the throat plate is provided with a U-shaped seat for the workpieces, whereby this seat encloses partially the stitch hole, and is provided with teeth on its circumference. An idler gear mating with the teeth of the inset and a further gear wheel also mating wi-h the idler gear are pivoted in the throat plate, whereby the gear wheel is fastened to a driven wheel which is in driving connection with the pattern-follower device through the transmitting means.

The transmitting means consists of an endless ball string, which is guided over guide pulleys pivoted on the sewing machine.

Brief description of the drawings FIG. 1 is a partial diagrammatic top plan view of a device for the automatic joining of workpieces by means of a double chain stitch sewing machine mounted on an arm, whereby the sewing machine is controlled by guiding patterns, and which ShOWs the pattern-follower device aligning the stitch hole;

FIG. 2 is a" section through the pattern-follower device on an enlarged scale;

FIG. 3 is a top plan view on the throat plate with the inset pivoted therein and driven by gear wheels.

Description of the preferred embodiment On an arm or hinged arm 1 (FIG. 1) of a device shown and described in U .8. Patent No. 3,276,405, for automatic sewing of workpieces 2 clamped in workpiece holders 3, there is secured a double chain stitch sewing machine 5, provided with a fabric carrier arm 4. The sewing machine 5 has a thread carrying needle 6, a workpiece presser pad 7 and is provided with a thread carrying looper and a thread spreader, which allows a formation of a scam in every possible feed direction.

A driven roller or magnetic roller 8 is supported in the arm or hinged arm 1 and is disposed coaxially with the needle 6. The roller or magnetic roller 8 coacts with a guiding pattern 9, mounted below the workpiece holder 3. On the driving shaft 10 for the roller or magnetic roller 8 there is provided a pattern-follower device 11. It consists of a lever 12 provided with a gauge finger 13, the lever 12 being secured to a bushing 14, pivoted on the driving shaft 10. Secured to the bushing 14 is a driving wheel 15 for a transmitting means 16 in the form of an endless ball string 17. The pattern-follower device 11 is under the tension of a torsion spring 18, which presses the gauge finger 13 against the guiding pattern 9 (FIG. 1).

The ball string 17 is guided over guide pulleys 19, pivoted on jibs 20, 21, and transmits the movements of the lever 12 to a driven wheel 22 (FIG. 1 and 3) which is arranged below the throat plate 23 and connected with a gear wheel 24 pivoted within the throat plate 23 (FIG. 3). With this gear wheel 24 mates an idler gear 25 likewise pivoted in the throat plate 23 and which mates with the teeth 26 of a throat plate inset 27 which is provided with an oblong stitch hole 28 for the needle 6. The throat plate inset 27 is provided with a U-shaped seat 29 for the workpiece 2, while the seat 29 encloses partially the stitch hole 28.

The arm or hinged arm 1 carrying the sewing machine 5, is guided along the outline of the pattern 9 (FIG. 1) in the direction of the arrow A by the driven roller or magnetic roller 8, whereby the needle 6 and the stitch forming tools produce a seam in the workpiece 2 corresponding to the shape of the pattern 9. The throat plate inset 27 is controlled by the pattern-follower device 11 over the transmitting means 16 and the gears 24, 25 in such a manner, that the oblong stitch hole 28 is aligned in the direction of the seam in order that it may form a satisfactory double chain stitch seam.

We claim:

1. In a sewing device, a double chain stitch sewing machine having a fabric carrier arm, a thread carrying needle, a thread carrying looper, a spreader, for forming seams in every feed direction; a workpiece press pad and a throat plate provided with an inset having an oblong stitch hole, said inset being pivoted in said throat plate and rotatable about the axis of said needle, a hinged arm articulated to said sewing device, said fabric carrier arm being arranged on said hinged arm, workpiece holders secured to said machine, guiding patterns mounted below said workpiece holders, a driven magnetic roller coacting with said guiding patterns and mounted in said hinged arm, the axis of said needle being in alignment with the axis of said magnetic roller, pattern-follower means for controlling said inset, transmitting means for said patternfollower means whereby the oblong stitch hole in said inset will be aligned according to the shape of said guiding patterns.

2. In a sewing device as claimed in claim 1, wherein said pattern-follower means includes a driving shaft for said roller, a lever pivoted on said shaft, a gauge finger secured to said shaft, a torsion spring pressing said finger against the guiding patterns, a driving wheel secured to said lever for transmitting the rotary motions of said gauge finger to said throat plate inset through said transmitting means.

3, In a Sewing device as claimed in claim 1, wherein said inset pivoted in said throat plate is provided with a U-shaped seat for said workpieces, said seat enclosing partially said stitch hole and being provided with teeth on its circumference, an idler gear mating with the teeth of said inset, a gear wheel mating with said idler gear and pivoted in said throat plate, a driven wheel in driving connection with said pattern-follower device through said transmitting means, said gear wheel being secured to said driven wheel.

4. In a sewing device as claimed in claim 1, wherein said transmitting means consists of an endless ball string, and guide pulleys pivoted on said sewing machine, said endless ball string being guided over said guide pulleys.

5. In a sewing device. having a double chain stitch sewing machine provided with a fabric carrier arm, a thread carrying needle, a thread carrying looper, a spreader for forming seams in every feed direction; a workpiece press pad and a throat plate provided with an inset having an oblong stitch hole; said inset being pivoted in said throat plate and rotated about the axis of said needle, said fabric carrier arm being arranged on said arm of said sewing device, workpiece holders mounted on said arm, guiding patterns mounted below said workpiece holders, a driven roller coacting with said guiding patterns mounted in said arm, the axis of said needle being aligned with the axis of said roller, throat plate inset transmitting means for transmitting movement to said inset from said guiding patterns for aligning the oblong stitch hole in said inset according to the shape of said patterns, said pattern-follower consisting of a driving shaft for said roller, a lever pivoted on said driving shaft, a gauge finger secured to said lever, a torsion spring pressing said gauge finger against said guiding patterns, a driving wheel fastened to said lever for transmitting the rotary motions of said gauge finger to said throat plate inset transmitting means therefor, said inset being provided with a -U-shaped seat for said workpieces, said seat enclosing partially said stitch hole and having teeth on its circumference, an idler gear mating with the teeth of said inset and a gear wheel mating with said idler gear, said gear wheel being pivoted in said throat plate, a driven wheel in driving connection with said pattern-follower device, said transmitting means consisting of an endless ball string guided over guide pulleys pivoted on said sewing machine, said gear wheel being secured to said driven wheel.

References Cited UNITED STATES PATENTS 6,181,50 12/1926 France.

JAMES R. BOLER, Primary Examiner U.S. Cl. X.R.