EP2733245A1 - Sewing machine - Google Patents

Abstract

The sewing machine (1) has a housing and stitch forming tools for seaming with a needle bar (9) that holds a sewing needle (10). A thread path setting unit has a projection element, which is arranged such that an upper thread runs between an upstream upper thread-guide component and a thread lever from a main-upper thread-guide plane. The main-upper thread-guide plane is defined by upstream upper thread-guide component. The projection element is displaced relative to the housing for providing an upper thread-path length between the upstream upper thread guide component and the thread lever.

Description

The content of the German patent application DE 10 2012 221 060.1 is incorporated herein by reference.

The invention relates to a sewing machine according to the preamble of claim 1.

The DE 10 2007 039 596 A1 describes such a sewing machine. Other sewing machines are known from the DE 10 2010 043 906 A1 , of the DE 10 2011 005 198 A1 and the US 2,184,929 , Such a sewing machine is also known by public prior use. A thread path presetting device is formed by a thread eye that can be adjusted in a main upper thread guide plane. When sewing, in particular with thick or flat upper threads or upper threads with a twist tendency, the known thread path presetting device has room for improvement.

It is therefore an object of the present invention to improve a thread path presetting device of a sewing machine in the upper thread path in front of the thread lever.

This object is achieved by a sewing machine with the features specified in claim 1.

According to the invention it has been recognized that the upper thread path can be influenced in its length not only in the main upper thread guide plane, but also perpendicular thereto. Such an influence provides the supernatant element of the thread path presetting device. The upper thread can then be performed in a controlled manner on a path that is performed even with difficult to be stitched upper threads with sufficient distance to other sewing machine components. An undesirable loops, which can lead to a disturbance of the threadline, is effectively avoided. The thread path presetting device may be arranged adjacent to a movement path of the thread lever. This can increase the effectiveness of the thread path presetting device. It is also possible to arrange a plurality of projection elements at different positions of the upper thread path. At least one further projection element can then be arranged in the upper thread path after the thread lever, in particular adjacent thereto.

A displaceable projection element according to claim 2 can be adapted to a default value for a threadless of the upper thread.

A design of the supernatant element as a bracket according to claim 3 has been found to be particularly suitable. The supernatant element can be manufactured inexpensively.

Alternatively, it is possible to form the at least one projection element as molded onto the housing solid or hollow body, in particular as a web body.

A convex bracket portion according to claim 4 leads to a controlled projection. The convex bracket portion can be particularly easily performed as a rounded kink.

A design according to claim 5 is safe.

In a design according to claim 6 can be adjusted in particular on the end-side adjustability a supernatant of the thread path-setting device and thus an upper thread path length between the upstream upper thread guide component and the thread lever.

Resting marks according to claim 7 have been found to be safe for setting various overhang values particularly suitable. There may be three or more locking marks depending on the design of the bracket.

Resting marks according to claim 8 are simple.

An arrangement according to claim 9 leads to an advantageous integration of various functional components on a common carrier, which simplifies manufacture and / or assembly of the sewing machine.

Fig. 1

perspektivisch eine bedienerseitige Ansicht einer Nähmaschine zum Vernähen von schwerem bzw. widerstandsfähigem Nähgut, wobei auch teilweise innenliegende Details einer Maschinenmechanik wiedergegeben sind;

Fig. 2

einen Ausschnitt einer Seitenansicht der Nähmaschine nach Fig. 1 im Bereich eines Nähmaschinenkopfes am Ende eines Arms der Nähmaschine;

Fig. 3

einen unterbrochenen Schnitt gemäß Linie III-III in Fig. 2;

Fig. 4

in einer zu Fig. 3 ähnlichen Darstellung eine Fadenweg-Vorgabeeinrichtung der Nähmaschine in Form eines Draht-Bügels im Vergleich zur Stellung nach Fig. 3 in einer anderen Relativposition eines Bügelendes zu einem Gehäuse der Nähmaschine; und

Fig. 5 bis 9

eine perspektivische Ansicht des Nähmaschinenkopfes in verschiedenen Armwellenposition zur Verdeutlichtung einer Funktion der Fadenweg-Vorgabeeinrichtung.

An embodiment of the invention will be explained in more detail with reference to the drawing. In this show:

Fig. 1

in perspective, a user-side view of a sewing machine for sewing heavy or durable fabric, which also partially internal details of a machine mechanism are shown;

Fig. 2

a section of a side view of the sewing machine after Fig. 1 in the area of a sewing machine head at the end of an arm of the sewing machine;

Fig. 3

a broken section along line III-III in Fig. 2 ;

Fig. 4

in one too Fig. 3 similar representation of a thread path-setting device of the sewing machine in the form of a wire strap in comparison to the position after Fig. 3 in another relative position of a strap end to a housing of the sewing machine; and

Fig. 5 to 9

a perspective view of the sewing machine head in different Armwellenposition to illustrate a function of the thread path setting device.

A sewing machine 1 has an upper arm 2, a vertical stand 3 and a lower housing, which is commonly referred to as a base plate 4. The sewing machine 1 is designed for sewing heavy or durable material, eg. As leather or plastic plates. The components 2 to 4, which form a housing of the sewing machine, are in the Fig. 1 only as far as their contours are concerned.

In the arm 2, an arm shaft 5 is rotatable on a schematically in the Fig. 1 indicated frame 5a stored. One of these arm shaft bearings is arranged in the region of a stator-side arm shaft end and another of the arm shaft bearings in the region of an opposite arm shaft end in a head 6 of the sewing machine 1. The drive of the arm shaft 5 and thus also the essential sewing components of the sewing machine 1 via a schematic in the Fig. 1 indicated high-power motor 7. About the arm shaft 5 and a crank mechanism 8 is a vertically mounted in the head 6 needle bar 9 vertically up and down driven, which carries a needle 10 at its lower end.

Below the needle bar 9, a barell gripper 11 is reciprocated in the base plate 4 about a gripper pivot axis 12 of a gripper rocker shaft 13 to and fro. The Barell gripper 11 is also referred to as a Barell shuttle. The gripper pivot axis 12 extends horizontally and parallel to the arm shaft 5. The barell gripper 11 cooperates with the sewing needle 10 for stitch and seam formation in the fabric. The barell gripper 11 and the sewing needle 10 represent stitching tools of the sewing machine 1. Instead of a barell gripper, another type of gripper can also be used.

The oscillating drive of the barell gripper 11 takes place via a gripper drive 14. The gripper drive 14 has a drive unit 15 for generating a transmission oscillation movement about a transmission oscillation axis 17.

The transmission oscillating axis 17 runs parallel to the shafts 5 and 13.

Furthermore, the drive unit 15 has a connecting rod 18. A rod end of the connecting rod 18 is designed as a rod eye 19, which is in driving connection with the drive shaft 5 via an eccentric unit. The other rod end of the connecting rod 18 is also formed as a rod eye and communicates with a transmission wheel 22 via an axial / radial bearing 23 in transmission connection. The transmission wheel 22 is pivotally mounted about the transmission oscillating axis 17 on a bearing bush 23a.

The crank rod 18 is in transmission communication with the transmission wheel 22 for swinging it back and forth about the transmission vibration axis 17.

Over an outer periphery of the transmission wheel 22, a traction means 25 of a traction mechanism 26 of the gripper drive 14 is guided. The traction means 25 is designed as a toothed belt. This meshes with an outer toothing on the outer circumference of the Transmissionsrades 22nd

The traction mechanism 26 is used to transmit the transmission oscillatory movement of the transmission wheel 22 about the transmission oscillation axis 17 in a drive-oscillating movement of the gripper rocker shaft thirteenth

For stitch and seam formation, the gripper body of the barell gripper 11 moves synchronously with the needle 10 and takes a needle thread loop which is passed through the fabric with the needle 10 and knots this by the upper thread during the movement of the gripper body to a Gripper housing is guided around and knotted.

For supporting components of the sewing machine 1 is a fixed in the region of the head 6 on the housing, one-piece support plate 27. The support plate 27 carries, inter alia, components for guiding an upper thread 28 (see Fig. 5 ). In the way of the upper thread 28, these are an upper thread guide eye 29, two upper thread tensioning devices 30, 31, a Fadenanzugsfeder 32, another upper thread guide eye 33 in the upper thread path in front of a thread lever 34, another upper thread guide eye 35 in the upper thread path after the thread lever 34th , an upper thread clamp 36 and two more upper thread guide eyelets 37, 38 in the upper thread path after the upper thread clamp 36th

The support plate 27 carries components of the upper thread tensioning devices 30, 31, namely actuators for opening and closing of clamping components of the clamping devices 30, 31, said actuators may be designed as a pneumatic cylinder. The voltage components can be tension discs. The tension discs are in the Fig. 3 shown at 38a. The support plate 27 further contributes to the mechanical release of the clamping devices 30, 31 a pivoting plate which can be pivoted between the tension discs 38 a.

On one of the viewer for example the Fig. 2 facing away from the support plate 27 has cable guides that can be designed as cable ducts in which both cable and pneumatic lines of the sewing machine 1 can be mounted.

The support plate 27 may be connected via a plug connection with a corresponding counter-body on the housing of the sewing machine 1. Towards the plug connection of the support plate 27, all the supply lines required for the operation of the components carried by the support plate 27 can then be guided. A counter-plug connection on the housing then ensures the connection of the components carried by the support plate 27 via the supply line connections connected thereto.

The thread lever 34 guides the upper thread 28. The thread lever 34 is synchronized with the stitch forming tools 10, 11 displaceable between a top dead center and a bottom dead center displaced. The position "thread lever top dead center" is in the Fig. 6 shown.

In addition to these components, the support plate 27 carries a thread lever protection body 39, which is an integral part of the support plate 27. The Fig. 2 and 5 show two versions of the thread lever protection body 39. In the execution according to Fig. 5 the thread lever protective body 39 is designed exclusively as a projection plate extending perpendicularly to the housing jacket, the outer contour of which is adapted to a movement path of the thread lever 34. In the execution after Fig. 2 the thread lever protection body 39 additionally has a front cover 40 which covers the path of movement of the thread lever 34 on the front side, ie towards the operator.

The thread lever protection body 39 may have a threading groove for facilitating threading of the upper thread 28 in the region of the thread lever 34.

Furthermore, the support plate 27 carries sewing machine controls on the one hand in the form of a multi-button control panel 41 with a total of six control buttons 42 and on the other hand in the form of a control button 43, the function can be pre-assigned.

Furthermore, the support plate 27 carries a winding device 44 for winding a yarn package.

Furthermore, the support plate 27 carries a position setting device 45 in the form of a setting wheel for setting the position of a relative position of the stitch forming tools 10, 11, that is, for preselecting a rotational position of the arm shaft fifth

Furthermore, the support plate 27 carries a lighting device 46, which in the Fig. 2 is shown schematically. The illumination device 46 serves to illuminate a section of a sewing field. This may be a sewing apron which represents a sewing field area in front of a puncture area of the needle 10 into a sewing material.

Finally, the support plate 27 carries a thread path presetting device 47 for influencing a length of upper thread path between the upper thread guide eye 33 as upstream in the upper thread path upstream of the thread lever 34 upper thread guide component and the thread lever 34 itself. The thread path presetting device 47 will be described in more detail below. The thread path presetting device 47 ensures that, for a given material thickness of the sewing material in the loop formation, the upper thread 28 runs with the correct tension over the gripper.

The support plate 27 carries all the yarn guide components of the sewing machine 1 from the upstream in the upper thread path abtragseitigen upper thread tensioning device 30, 31 to the thread lever 34. Furthermore, the support plate 27 carries all yarn guide components of the sewing machine 1 in the upper thread path from the thread lever 34 to the sewing needle 10th

The upper thread path of the upper thread 28 between the upper thread guiding eye 29 and the upper thread guiding eye 38 is indicated by way marks 47a on the support plate 27. These way marks 47a are designed by raised or recessed executed in the support plate 27 markings. The way marks 47a facilitate threading of the upper thread 28 along the upper thread path.

The thread path presetting means 47 has a protrusion member arranged such that the upper thread 28 is formed between the upper thread guide eye 33, which is an upstream upper thread guiding component in the upper thread path in front of the thread lever 34, and the thread lever 34 is made of a main upper thread guiding plane runs out. This main upper thread guide plane is defined by the upper thread guide eye 33, by the thread lever 34 and by the upper thread guide eye 35 as a downstream upper thread guide component in the upper thread path after the thread lever 34. The main upper thread guide plane is approximately parallel to the plane of the Fig. 2 ,

The projection element of the thread path presetting device 47 is designed as a bracket 48. This bracket extends transversely to the upper thread run between the upper thread guide eye 33 and the thread lever 34. As an alternative to a bracket, the supernatant member 48 also, comparable to the thread lever protection body 39 in the embodiment according to Fig. 5 , be formed as a bridge body.

The bracket 48 has a convex strap portion 49 that defines a region of large overhang of the protrusion member 48 over the main needle thread guide plane. The convex bracket portion 49 is executed in the illustrated embodiment as a rounded kink portion of the bracket 48.

Both ends 50, 51 of the bracket 48 are fixed to the housing of the sewing machine, namely on the support plate 27. A mounted in the upper position 50 of the bracket 48 is about a pivot axis 52 (see Fig. 2 ), which extends parallel to the arm 2, mounted in a pivot-fixing bearing 53 of the support plate 27. In the area of this end 50 of the bracket 48 is 90 ° compared to its other main extension parallel to a face plate portion 54 of the head 6 kinked.

At the other, in the mounted position lower end 51, the bracket 48 is adjustably mounted on the housing of the sewing machine, namely on the support plate 27. In the region of the strap end 51 of the bracket 48 is in turn bent by 90 °, with an end-side strap portion to the strap end 51 out perpendicular to the plane of the Fig. 2 extends.

The adjustability is vivid in the Fig. 3 and 4 shown in two different relative positions of the end 51 of the bracket 48. The bracket 48 has at the adjustable end 51 in the illustrated embodiment a total of four locking marks, which are designed as mounted in the adjustable strap end 51 locking grooves 55, 56, 57 and 58. The locking grooves 55 to 58 cooperate with a counter body in the form of a spring 59 of the support plate 27 for specifying the respective relative position of the adjustable strap end 51 to the housing. Fig. 3 shows the position in which the counter body 59 cooperates with the farthest from the adjustable strap end 51 arranged locking groove 58.

The relative position after Fig. 3 causes the convex bracket portion 49 comparatively close to the support plate 27 zoom, so that the supernatant of the convex bracket portion 49 is minimized on the support plate and thus also on the main upper thread guide level.

Fig. 4 shows the relative position of the adjustable strap end 51 to the support plate 27, in which the counter body 59 with the bracket end 51 next adjacent locking groove 55 cooperates. In this relative position, the bracket 48 and in particular the convex bracket portion 49 has the largest Projection to the support plate 27 and thus also to the main upper thread management level. By interaction of the counter body 59 with the intermediate locking grooves 56 or 57 can be correspondingly projections of the convex ironing section 49 on the main upper thread guide plane produce, between the maximum supernatant to Fig. 4 and the minimum supernatant Fig. 3 lie. Depending on how much threadless is generated, the supernatant position of the bracket 48 is set on the adjustable strap end 51. A large threadless plays a role especially in thick sewing material to be sewn.

In the course between the convex bracket portion 49 and the bent by 90 ° end 51 of the bracket 48 has sections a curved course to maintain a minimum distance to Fadenanzugsfeder 32.

The Fig. 5 to 9 illustrate the function of the thread path presetting device 47.

Fig. 5 shows an arm shaft position "0 °" at which the needle 10 is at top dead center of its travel. The thread lever 34 is in the Armwellenposition after Fig. 5 On the way up.

Fig. 6 shows the Armwellenposition "60 °" with the thread lever 34 at top dead center. The upper thread 28 is stretched between the Fadenanzugsfeder 32 and the thread lever 34, in particular between the upper thread guide eye 33 and the thread lever 34, and is located on the bracket 48 in a region between the convex bracket portion 49 and the pivotable end 50 at.

Fig. 7 shows the Armwellenposition "160 °", in which the thread lever 34 is from top dead center on the way down. Accordingly, the upper thread 28 in the thread path between the upper thread guide eye 33 and the thread lever 34 is no longer tensioned, but loose. This is also called "threadless". The thread path presetting device 47 ensures that the loose upper thread 28 between the upper thread guide eye 33 and the thread lever 34 has a defined course. The upper thread 28 rests against the bracket 48 again between the convex bracket portion 49 and the pivotable end 50.

Fig. 8 shows the Armwellenposition "220 °", in which the thread lever 34 is on its further way down and is approximately at the level of the convex ironing portion 49. The upper thread 28, which is now even more loose than the Armwellenposition after Fig. 7 , abuts on the bracket 48 in the region of the convex bracket portion 49. The shape of the bracket 48 forces here a defined course of the upper thread 28 between the upper thread guide eye 33 and the thread lever 34. It is in the arm shaft positions between the positions of the Fig. 7 and 8th in particular prevents an uncontrollably large upper thread loop forms.

Fig. 9 shows the Armwellenposition "270 °", in which the thread lever 34 is in the region of its bottom dead center. The upper thread 28 is now on the bracket 48 in the area between the convex bracket portion 49 and the adjustable strap end 51 at.

Another supernatant element on the type of supernatant element, which has been described above in connection with the thread path presetting device 47, can be arranged in the upper thread path after the thread lever 34 be. In particular, the two supernatant elements, so for example, the bracket 48 and another supernatant element, which may also be designed in the form of a bracket or a solid or hollow body, be disposed on both sides of the thread lever 34 and adjacent thereto.

Claims (9)

Sewing machine (1) with a housing (2, 3, 4), - with stitch forming tools (10, 11) for seam formation including a needle bar (9) for holding a sewing needle (10), with a thread lever (34), - - which leads an upper thread (28) - - and synchronized with the stitch forming tools (10, 11) driven between a top dead center and a bottom dead center is displaceable, - With an upstream upper thread guide component (33) in the upper thread path in front of the thread lever (34), - with a downstream upper thread guide component (35) in the upper thread path after the thread lever (34), - With a length of the upper thread path between the upstream upper thread guide component (33) and the thread lever (34) influencing thread path-presetting device (47), characterized in that the thread path presetting device (47) at least one projection element (48), which is arranged such that the upper thread (28) between the upstream upper thread guide component (33) and the thread lever (34) runs out of a main upper thread guide plane, which is defined by the upstream upper thread guide component (33), the thread lever ( 34) and the downstream upper thread guiding component (35). Sewing machine according to claim 1, characterized in that the projection element (48) relative to the housing (27) is displaceable to Specification of an upper thread path length between the upstream upper thread guide component (33) and the thread lever (34). Sewing machine according to claim 1 or 2, characterized in that the projection element (48) is formed as a bracket, which extends transversely to the yarn path of the upper thread (28) between the upstream upper thread guide component (33) and the thread lever (34). Sewing machine according to claim 3, characterized in that the bracket (48) has a convex bracket portion (49). Sewing machine according to claim 3 or 4, characterized in that both ends (50, 51) of the bracket (48) on the housing (27) are fixed. Sewing machine according to one of claims 3 to 5, characterized in that the bracket (48) is adjustable at least at one end (51). Sewing machine according to claim 6, characterized in that the bracket (48) has at least two latching marks (55 to 58) provided with a housing (27) fixed counter body (59) for specifying a respective relative position of the adjustable strap end (51) to the housing (27) interact. Sewing machine according to claim 7, characterized in that the latching marks (55 to 58) are designed as locking grooves mounted in the adjustable strap end (51). Sewing machine according to one of claims 1 to 8, characterized in that the thread path presetting device (47) and the two upper thread guide components (33, 35) are supported by a common support plate (27) fixed to the housing (2 to 4) is.

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