DE8033162U1 - TRANSPORT DEVICE FOR INDUSTRIAL SEWING MACHINES - Google Patents

Description

^: * 734β luJ) W46sbi2rq · 5, · 1 2 .1980

PATENT ADVERTISER RUF 071 41/44830

Heinz Hoss e.Z .: H 1. 12. D 3

7o22 Leinfelden-Echterdingen H 1. 22. D 3

Transport device for industrial sewing machines

In the case of a sewing machine, the conventional transport device a throat plate with elongated throat plate windows and a feed dog with several sawtooth-like formed rows of teeth that reach through the needle plate window from below. Above the throat plate is a sewing foot which is movably guided on a vertical guide and which is in the Operating state pressed downwards against the throat plate and the rows of teeth of the feed dog by means of spring force will. The sewing foot has smooth sliding or smooth surfaces on its underside, at least in the area of the throat plate window and thus in the area of movement of the rows of teeth of the feed dog Guide surfaces for the sewing material on »The rows of teeth of the feed dog are in one work cycle over the upper side of the throat plate raised position in the sewing direction forwards and in a position under the top the throat plate moved backwards against the sewing direction. As the The sewing material lying between the throat plate and the sewing foot is fed step by step until the rear edge of the sewing material has passed through the sewing station and the seam is completed.

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In industrial sewing machines M / earth the same f

Large numbers of sewing material parts at a short distance f,

sewn consecutively. After completing the 1st

The machine continues to sew a sewing part and Ij

creates an exposed chain of threads until the next |

The sewing part is fed to the sewing station and the thread chain j becomes the seam of this sewing part. Two consecutive Sewing parts that are connected to one another via such a thread chain must be separated from one another. This is done either with scissors, which are operated by the seamstress by hand, or with a cutting device powered by the seamstress a hand, foot or knee movement is controlled. Sometimes the control is also carried out by photocells.

There are two methods of cutting by hand using scissors. In one case the seamstress grasps it the last sewing part sewn by hand, cuts the intermediate thread chain and puts this sewing part in one Container. With the other method, the seamstress leaves a larger number over the intermediate thread chain Connected sewing parts fall into a collecting container and after sewing the last sewing part, she takes out the connected sewing parts and separates the sewing parts pull apart on the thread chain using scissors and store the individual sewing parts in another container. These separation processes are very time consuming.

When using a cutting device, the seamstress has to hand over the finished sewing part via the sewing station Pull far out so that the end of the sewing part has reached the cutting station with the cutting device.

In the case of a cutting device controlled by the seamstress, the thread chain is generally only severed. With a cutting device controlled by photocells, it is possible to cut the free thread chain both at the end of the previous sewing part and at the beginning of the next
Cut off the sewing part. But also with one of these
The seamstress has to cut the sewing parts by hand
pull it out of the sewing station over the cutting station. The seamstress can therefore only start sewing the next sewing part when the thread chain has been cut. Since the sewing of the seam is usually done very quickly,
these idle times reach a considerable proportion
in the total production time of a sewing part.

A reduction of this disadvantage has been attempted with a puller in which an endless, revolving
There is a conveyor belt, one strand of which is guided by means of guide rollers above an extension of the sewing table, which runs in the direction of movement of the sewing parts
arranged beyond the cutting device and means
a carrier running below the lower blade of the cutting device is connected to the sewing table. However, such a conveyor belt can only be brought up to the sewing part to be removed beyond the cutting device. There is therefore a connection between the point of engagement of the conveyor belt on the sewing part and the transport system of the sewing machine
larger length of the sewing part unguided. at
very short seams, for example shoulder seams of
Sports jackets and the like, especially with a larger laterally adjoining piece of fabric, it can happen that the end of the sewing part has already left the transport system of the sewing machine, but its beginning has not yet reached the conveyor belt. Then the danger is very great

that the sewing part remains in the cutting device and is cut by this. For sewing parts that have an uneven seam path, i.e. those with surface areas of the sewing part that are present on both sides of the seam and have different drainage rates come out of the sewing station, the surface area with the higher running speed bulges up and pushes the seam to the side · This becomes within the unguided stretch area between the Transport system of the sewing machine and the conveyor belt of the puller run sideways so that they are from Conveyor belt is not or at least not detected in the middle and therefore when cutting the thread chain, before Difficulties can arise especially at the beginning, but also at the end of a sewing part. This page delay it requires that the knife of the cutting device be made relatively long transversely to the sewing direction must so that a laterally distorted thread chain can be cut safely. Because of the page warpage and because of the great length of the knife of the cutting device, the risk is again very great that the Cutting device cuts into the workpiece. In addition, the cutting device can because of its large Dimensions only at a greater distance from the sewing station be arranged, which also contributes to the aforementioned disadvantages.

The invention specified in claim 1 is based on the object of a transport device for industrial sewing machines to create a quick and safe separation of the work pieces by means of a cutting device enables.

By extending the transport device by means of an additional throat plate window, or by means of a corresponding extension of existing throat plate fenders, by means of additional rows of teeth or by means of rows of teeth present with a corresponding extension on the feed dog and by means of the corresponding extension of the sewing foot, the sewing material parts are grounded one more time continued straight ahead for a certain distance. This uiird the zM / ischen two adjoining parts of the sewing material The existing thread chain is also guided straight and kept taut. The thread chain will even be at vastly different size and weight ratios the surface areas of the sewing material adjoining the seam on both sides are not laterally distorted. By the lack of lateral distortion of the sewing material is for the lower knife and the upper knife of the cutting device at this point transversely to the sewing direction only a relatively short length is required, so that the the knife of the cutting device receiving recess in the throat plate laterally only needs to have such a small extension that it is between the additional Throat plate windows or corresponding extensions the existing throat plate window at a very short distance Arranged behind the middle throat plate windows and rows of teeth for the transport of the thread chain can be. Because of this and because of the short length of the knife of the cutting device can be without risk of Cut the thread chain very close to the edge of the sewing material adjoining on both sides relevant workpiece are cut off. This can even be done with a single severing cut. That results in an increase in working speed because the sewing machine no longer has to perform one twice

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Separation cut must be stopped. In addition, this results in a considerable reduction in thread consumption, '■;'.

whereby one has to consider that the sewing material parts are usually marked with §

¹ I several threads at the same time, usually with |

six to nine threads, to be sewn. * j

In the case of a transport device designed according to claim 2, the advantages of the invention are further enhanced, because the guidance of the work pieces with a corresponding tight tension of the thread chain is still over the cut-off point has an effect. In a transport device designed according to claim 3, is also a wider thread chain is sure to be completely cut. In one according to claim 4 configured transport device, the upper knife of the cutting device requires only a very small one Space for movement in the vertical between the extension of the guide surface of the presser foot and the surface above it other parts of the presser foot. As a result, a relatively small recess open on one side is sufficient on the sewing foot not only to get the upper knife right up to the sewing foot but at least partially even in the area of the To insert the presser foot. This will bring the cutting device closer to the sewing station and to reaches the middle throat plate window and the associated rows of teeth of the feed dog. Through an arrangement the transport device according to claim 5 is prevented that when cutting the thread chain from Upper knife pulled into the recess of the beginning of the thread chain of the following workpiece when sewing further runs further into the recess and / or is located in the recess on any structural parts caught and disturbs the sewing operation, or that severed

Remnants of the thread chain stick to any moving construction parts inside the sewing machine and-impair their guides. With an embodiment the transport device according to claim 6 is very simply constructed and takes up little space Ejector created. Through the development according to claim 7, the penetration of residues the thread chain between the lower knife and the ejector reliably prevented.

In the case of a transport device designed according to claim 8, the upper knife of the cutting device receives an additional guide so that it can also be used when cutting through a thicker thread chain or one or of several bands running along with the thread chain does not evade laterally, but a smooth cut executes. The development according to claim 9 can the guide device quickly and safely adjust to the correct position in relation to the cutting device and if necessary just as easily and safely readjust. In the embodiment of the transport device according to claim 10 it is achieved that the guide surface even in the event of an unintentional or intentional Rotation of the sewing foot around its sewing foot bar always has the correct distance to the upper knife and a one-sided Displacement of the upper knife on the lower knife is avoided.

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In the following the invention will be explained with reference to an embodiment shown in the drawings explained in more detail. Show it:

Fig. 1 is a partially sectioned end view of the transport device according to the Invention;

Fig. 2 is a partially sectioned side view the transport device according to FIG. 1;

3 shows a plan view of part of the transport device according to FIGS. 1 and 2;

4 shows a detail and enlarged side view of the transport device with a Ejector;

FIG. 5 shows a partial rear view of the ejector according to FIG. 4;

Fig. 6 is a fragmentary plan view of the Transport device with ejector according to FIG. 4.

7 is a side view shown in detail the transport device with a guide device for its cutting device;

Fig. 8 is a fragmentary and partially sectioned The illustrated top view of the guide device according to FIG. 7.

The transport device 10 is shown in FIGS. 1 to 3 in connection with a free-arm sewing machine 11 for the Down arm sewing method shown, on which the transport device 10 has a particularly favorable effect. The ireiarm 12, one of the sewing needles 13 and the sewing foot 14 are at least of this sewing machine 11 hints at recognizing * the transport device v / e is a throat plate 15, a feed dog 16 and a cutting device 17.

In the vicinity of the free end of the free arm 12, the throat plate 15 is on its top in a Flat recess matched to the floor plan, let in flush and screwed tight. The throat plate 15 has several groups of elongated, rectangular throat plate windows 18, 19, 2o and 21. They are all parallel to the sewing direction, that is in Fig. 3 from right to left, aligned. The stitch plate windows are arranged in pairs symmetrically to the longitudinal center line of the throat plate 15. From that in Fig. 3 on the right Group of throat plate windows 18 and 19, the inner throat plate windows 19 have a smaller one Width than the outer steel plate windows 18. Both pairs of needle plate windows have the same length and lie next to each other in the same way. From the group of throat plate windows on the left in FIG. 3 20 and 21 have the inner throat plate windows 21 also has a smaller width than the outer throat plate window 20. The throat plate window 20 close directly to the throat plate window 18., whereby the boundary lines on both sides are aligned with one another. The stitch plate window 20. point in the length section in which

the inner or middle throat plate windows 21 are each a widening of constant width on the inside. At the end of the widening of the throat plate window 20 each is followed by an extension. Its outer boundary line is aligned with the % \

outer boundary line of the merging |

Throat plate window 20 and 18. The inner boundary a

line of extension 22 is approximately on the fi

Alignment line of the inner boundary line of the not widened Throat plate windows 20 and 18.

At a short distance from the end of the needle plate window and the widening of the needle plate window 20 is located In the throat plate 15 is a continuous recess 23 with a rectangular plan. Across the In the sewing direction, the recess 23 extends slightly beyond the alignment of the inner boundary line the widening of the throat plate window 20, which at the same time corresponds approximately to the alignment of the outer edge of that web of the throat plate 15, the between the inner throat plate windows 21 and the Widening of the outer throat plate window 20 is available is. In the sewing direction, the recess 23 has such a large dimension that the knife of the cutting device have enough space.

In the sewing direction between the inner throat plate windows 19 and 21 is located in the throat plate 15 a needle plate 24 with the needle holes 25 for the needles 13. This needle plate 24 is, as usual, in a recess in the needle plate 15 let in and screwed into it.

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Within the free arm 12 there are two conveyors, each of which has several rows of sawtooth-like teeth, their design and arrangement the assigned throat plate window is coordinated through which they reach when the conveyor is raised. The conveyor on the right in FIG. 3 is not shown for reasons of clarity. The conveyor 16 on the left is open to a pair of rows of teeth 26 and 27. The inner rows of teeth 27 are of constant width. The outer teeth are 26 stitches, like the needle plate window 20, a first length section with a certain width to which a length section with a larger width. An extension 28 connects to the last-mentioned length section, the length and width of which are matched to the extension 22 of the throat plate window 20. How out Fig. 3 can be seen, extend both the extensions 22 of the throat plate window 20 as also the extension 28 of the rows of teeth 26 in the sewing direction beyond the end of the recess 23.

The sewing foot is located above the throat plate 15 14th It is vertically up and down on a longitudinal guide (not shown) on the sewing machine movably guided. In the operating position it is pushed downwards by a spring with a certain force Throat plate 15 pressed. On the side facing the throat plate, the sewing foot 14 has a sole with smooth sliding or guide surfaces for the sewing material, which when sewing between the throat plate 15

urid of the sole 29 by the conveyor 16 step by step is pushed through. The guide surfaces of the Sole 29 have a plan that is at least the plan of the movement space of the rows of teeth 26 and of the conveyor 16 covered. The sole 29 also has two extensions aligned in the sewing direction 30, which is at least the plan of the movement space of the extensions 28 of the row of teeth 26 of the conveyor 16 cover. The mentioned guide surfaces of the sole 29 of the presser foot can be formed by the underside of the presser foot body itself. But you can also, as many times common, through the underside of runner-shaped inserts are formed in the underside of the stitching joint, which are themselves designed to be elastically flexible and / or resilient being held.

The cutting device 17 has a lower knife 31 and an upper knife 32, both of which are transverse to the sewing direction aligned; are. The lower cutter 31 is arranged on the free arm 12 so that it is along the In the sewing direction, the rear edge of the recess of the throat plate 15 protrudes into the recess 23 and with its cutting edge just below the top of the throat plate 15 remains. The upper knife 32 is on attached to a pivot arm 33, by means of which it is down from a rest position above the lower blade 31 can be moved towards this until the cutting engagement with the lower knife. The swivel arm is pivotably mounted by means of a pivot bearing 34, which in turn is arranged on a holder 35 is, which is rigidly connected in a manner not shown with the housing of the sewing machine. The swivel drive

for the Schvi / enkarm 33 and the Obermosser attached to it 32 supplies a pneumatic calving drive, of which only the piston rod 36 in FIG. 1 is included a kappel joint 37 can be seen.

The upper knife 32 has a vertical plane running parallel to the longitudinal center line of the throat plate 15 an L-shaped cross section (Fig. 2). The above horizontally extending profile leg 38 is in the sewing direction aligned. The perpendicular one below Profile leg 29 is on the lower knife aligned. The lower edge of the profile leg 39 is sharpened to form a cutting edge. The profile leg 39 with the cutting edge has an extension transversely to the sewing direction that is slightly smaller than the Expansion of the recess 23 in the throat plate 15 measured in the same direction · From the L-profile of the upper knife 32, only the above horizontal profile leg 38 extends over the extension 30 of the sole 29 of the sewing foot 1.4 and over the throat plate .15 to the pivot arm 33 out.

In the following, an ejector is explained with reference to FIGS. 4 to 6, the one in FIGS. 1 to 3 for better clarity was not shown because of. The ejector 4o sits below the recess 23 in the movement path of the upper knife 32.

The ejector 40 has a head oriented transversely to the sewing direction and thus parallel to the lower cutter 31 on. The ejector head 41 has a flat top.

The long side facing the lower cutter 31 is smooth throughout. The long side facing away from it is over the entire length of the head (transversely to the sewing direction) offset so that an L-shaped cross-section is created. the Plan dimensions of Ausu / erferkopfes 41 are based on the Dimensions of the recess 23 matched so that when the lower cutter 31 is inserted, it is the one that is left free Part of the recess 23 is at least almost completely filled and only that for its flexion The clearance required in the recess 23 in relation to the boundary surfaces of the recess 23 remains. Of the Head 41 is attached to the upper end of a leaf spring-like bracket 42, preferably through Brazing. The lower end of the holder 42 is attached to an approximately Vi / cube-shaped slide 43. Of the Carriage 43 has a vertically aligned circular cylindrical through hole 44, the diameter of which is matched the shaft diameter of a shaft screw 45 is that the set screw 45, more precisely its threadless shaft 46, a guide for the Slide 43 forms. This set screw 45 is used Attachment of the end of the throat plate 15 to a housing cover 47, which in turn is connected to the free arm 12 in is screwed in a manner not shown. The housing cover 47 ″ is closed to catches 48 and 49 in each of which has a smooth cylindrical through hole, which in both lugs 48 and 49 with each other cursing. The rear side 50 of the slide 43 facing away from the holder 42 has from the longitudinal axis of the Through hole 44 a distance that for a Running clearance required is less than the distance the inside of the housing cover 47 from the longitudinal axis the through holes in the lugs 48 and 49, which the

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Pick up shaft 46 of shaft screw 45. This forms the back 50 of the carriage 43 with the inside of the housing cover 47 a further guide, which at the same time a rotation lock for the carriage 43 and thus for the ejector head 41 forms.

Between the carriage 43 and the one below A helical spring 51 is arranged as a compression spring to catch 49 of the housing cover 47. She is sitting on the Shank 46 of the set screw 45 and is guided thereby.

j The bracket 42, which is preferably made of spring steel is, is designed and arranged so that the ejector head 41 a slight bias in the direction on the lower knife 31 receives. As a result, the ejector head 41 is both in its rest position and j

also with its vertical movements always on the lower knife. This gives the ejector head 41 an additional one Leadership that prevents him from acting on inertia forces acting on it or other forces, for example on the part of the upper knife, against that of the lower knife 31 facing away from the edge of the recess 23 could encounter. At the same time, this system prevents the lower knife 31, that there remains of the thread chain or lint penetrate and could affect the guidance of the ejector.

The length of the bracket 42 is based on the dimensions of the Carriage 43 and the head 41 as well as the distance between the underside of the lug 48 and the upper side of the throat plate 15 matched so that in the above rest position of the ejector 40 (Fig. 4) the top of his

. .11 lit I

The head 41 is flush with the top of the throat plate 15 is. As a result, the top of the head 41 simultaneously forms a guide for the sewing parts and the thread chain, so that these can be pushed away more easily over the recess 23.

A guide device is described below with reference to FIGS. 7 and 8 52 for the cutting device 17 explained, which in Fig. 1 and Fig. 2 for better clarity was not shown because of.

The guide device 52 is arranged on the sewing foot 14. The main part of the guide device 52 is a guide body 53 with an L-shaped plan. Its parallel to the Upper knife 32 of the cutting device 17 extending leg provides a guide plate 54 for the upper knife The outer side of the guide plate 54 facing the upper cutter 32 is a circular cylinder surface, the cylinder axis of which is at least approximately aligned with the longitudinal axis of the sewing foot bar 56. For simplification The manufacture of this outside can also have the shape of a roof, if only care is taken that the two Surface areas on both sides of the ridge line do not protrude beyond the circular cylinder surface, the cylinder axis of which in turn is aligned with the longitudinal axis of the sewing foot bar 56.

The second leg 57 of the guide body 52 is used Holder of the guide body on the sewing foot 14. For this purpose it has a through hole, namely a horizontal one aligned elongated hole 58, in which the shaft 59 of a fastening screw 60 engages, which is in a threaded hole 61 of the sewing foot 14 is screwed in. Through this design of the holder, the guide device above all in the sewing direction up to the contact with the upper knife this can be approached. Then it is screwed tight.

The one in Fig. 7 to / ischen the upper knife 32 and the Guide device 52 recognizable distance has only been observed for the sake of clarity of the representation. If the guide device is set correctly, it is not present «

Claims (10)

Expectations 1. Transport device for industrial sewing machines, with a throat plate with throat plate windows, with a feed dog with rows of teeth reaching through the throat plate window, and with a Cutting device, each with a lower knife and an upper knife aligned transversely to the sewing direction, of which the lower knife is arranged in a stationary manner and of which the upper knife by means of a laterally outside the throat plate arranged Schv / enklager with is pivotably mounted parallel to the sewing direction aligned axis, characterized in that in the throat plate (15) at a short distance behind the throat plate windows (21) for the two middle ones that are used to transport the thread chain Rows of teeth (27) of the conveyor (16) a recess (23) is present, the clear width in the sewing direction is at least equal to the sum of the dimensions of the bottom knife measured in the sewing direction (31) and the oversize (32), and their clear width transversely to the sewing direction is greater than that Width of the sewn thread chain is that in the -2- Throat plate (15) on both sides of the recess (23) there is an additional throat plate window each, or that the throat plate windows (20) located in the same alignment line have a corresponding extension (22) aufvi / iron that on the feed dog (16) in the area of the additional throat plate window or the corresponding extensions (22) each have an additional row of teeth, or that the rows of teeth (26) located in the same alignment line each have an extension (23), and that the sewing foot (14) in the area of the additional throat plate window or the corresponding extensions (22) each has an extension (20) which extends in the sewing direction at least approximately to the end of the additional Throat plate window or the corresponding one Extensions (22) extend. 2. Transport device according to claim 1, characterized in that the additional throat plate window or the corresponding Extensions (22) extend beyond the end of the recess (25) in the sewing direction . 3. Transport device according to claim 1 or 2, characterized in that that the clear width of the recess (23) transversely to the sewing direction is at least as large as the distance of the edge of the two webs of the throat plate (15) facing away from one another, the one on both sides of those throat plate windows (21) through which the two middle rows of teeth (27) of the conveyor (16) reach . -3- 4. Transport device according to one of claims 1 to 3, characterized in that the upper knife (32) in the area of the recess (23) in a vertical plane extending along the sewing direction has an L-shaped cross section from which from inside the edge of the recess (23) to at least outside the throat plate (15) and the Sewing foot (14) only the above horizontal profile leg (38) continues. 5. Transport device according to one of claims 1 to 4, characterized in that that in the recess (23) an ejector (40) is present, the from the lower knife (31) of the cutting device (17) exposed part of the recess (23) at least approximately completely fills, the top of which is flush with the top of the in the rest position The throat plate (15) can be moved up and down in the recess by means of a vertical guide (43, 45) is guided, and which is under the force of a return spring (51) directed towards the recess. 6. Transport device according to claim 5, characterized in that the ejector (40) has an exposed part the recess (23) has at least approximately completely filling head (41) which is directly or is attached by means of an intermediate piece (42) to a carriage (43) which is attached to a vertical Guide (46) is guided up and down movable, preferably as a guide of the thread-free Shank (46) of a fastening screw (45) of the The throat plate (15) is used, and the slide (43) is a circular-cylindrical one that is matched to the guide (46) Has through hole (44) and an outer surface (50) which is aligned parallel to the axis of the through hole (44) and of this one Has a distance which is at least approximately equal to the distance between the axis of the fastening screw (45) from an adjacent wall surface of a housing part (47). 7. Transport device according to claim 6, characterized in that that the intermediate piece between the head (41) of the ejector (40) and the carriage (43) as a leaf spring (42) is formed, which is shaped so that the head (41) of the ejector (40) on him facing side surface of the lower blade (31) rests with a certain bias. 8. Transport device according to one of claims 1 to 7, characterized in that that on the sewing foot (14)> or on a part connected to it, a guide device (52) for the upper knife (32) of the cutting device (17) is present, preferably by at least one in the sewing direction with respect to the sewing foot (14) adjustable guide plate (54) is formed. -5- 9. Transport device according to claim 8, characterized in that that the guide plate (54) is designed as part of a guide body (53), the one L-shaped or C-shaped plan, of which at least one leg (57) is parallel to one the side surface of the sewing foot (14) aligned with the sewing direction and a through hole, preferably an elongated hole (58) for the shaft (59) of a fastening screw (60) to pass through on M / eist. 10. Transport device according to claim 8 or 9, characterized in that that the outer side (55) of the guide plate (54) facing the upper knife (32) as a cylindrical surface, preferably designed as a circular cylinder surface whose cylinder axis at least approximately coincides with the longitudinal axis of the sewing foot bar (56) is in alignment, or. that the outside is designed at least as a roof surface, the two surface areas of which do not go beyond a circular cylinder surface touching the ridge line, the cylinder axis of which is aligned with the longitudinal axis of the presser foot bar.