EP2660378B1 - Sewing machine - Google Patents

Description

The invention relates to a sewing machine, in particular a heavy-duty sewing machine, so a sewing machine for sewing very resistant or very strong material.

Sewing machines and especially heavy duty sewing machines are known in many designs. The DE 30 43 141 A1 and the DE 34 23 843 C2 each describe an upper transport device on a sewing machine. The JP-A-2 193 693 describes another embodiment of an upper transport device for a sewing machine.

It is an object of the present invention to further develop a sewing machine having a hopping mechanism connected to a transporting foot for suture conveying and a presser foot for jamming cloth holding for reciprocating, hopping raising and lowering relative to a platen such that this hopping mechanism practically unaffected by a sewing material thickness works.

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

The inventive articulation of the hoppers member with the Hüpferantrieb via a drive member with a guide groove causes a thickness or thickness of the sewing material to be sewn has no effect on the Hüpferbewegung the transport foot and the presser foot. Even with very thin or with very thick fabric, the transport foot and the presser foot can be driven in the same way by the hoppers for hopping lifting and lowering. The guide groove of the joint the Hüpfergliedes with the drive member may be performed on the drive member or on the Hüpferglied. The frame lever connection, in which the drive member is connected via the frame lever to the frame, ensures a stable coupling of the drive member.

A triangular lever mechanism according to claim 2 can be realized compact and with comparatively few mechanical components.

A Gleitnutplatte according to claim 3 is a robust variant for the drive member.

A sliding block according to claim 4 avoids tilting in the region of the guide groove and reduces wear.

A Hüpfergetriebe according to claim 5 allows an adjustment of the Hüpferantriebs to the respective sewing requirements. The Hüpfergetriebe can be driven by an arm shaft of the sewing machine, from which also a movement of other sewing components, in particular the needle bar can be derived. With the Hüpfergetriebe the Hüpferhub can be specified in particular continuously. The frame lever, via which the drive member is connected to the frame, can form a parallelogram arrangement with a gear lever according to claim 5. Such a parallelogram arrangement is stable.

A driven pivotable Nadelstangerahmen according to claim 6 provides a robust way for the material to be transported. Such a fabric needle transport can be designed synchronized with the Transportfußbewegung synchronized.

An articulation of the frame lever according to claim 7 leads to a compact construction. There is then no separate frame holder for the drive member necessary.

Fig. 1

eine Seitenansicht einer Nähmaschine aus Sicht eines Bedieners;

Fig. 2

eine Explosionsdarstellung einer Hüpfermechanik und einer Nadelstangenmechanik der Nähmaschine;

Fig. 3

die Hüpfermechanik und die Nadelstangenmechanik nach Fig. 2 in montierter Form, dargestellt mit einem Nähgut mit 2 mm Dicke, mit einem Drückerfuß in einer oberen Position, einem Transportfuß in einer unteren Position und der Nadelstange in einer unteren Position relativ zu einer Auflageplatte;

Fig. 4

in einer zu Fig. 3 ähnlichen Darstellung die Hüpfermechanik und die Nadelstangenmechanik mit dem Drückerfuß in einer unteren Position, dem Transportfuß in einer oberen Position und der Nadelstange in einer oberen Position relativ zur Nähgut-Auflageplatte;

Fig. 5

die Hüpfermechanik und die Nadelstangenmechanik in einer Stangenstellung, die derjenigen nach Figur 3 entspricht, allerdings mit einem Nähgut mit 20 mm Dicke;

Fig. 6

die Hüpfermechanik und die Nadelstangenmechanik in einer Stangenstellung nach Fig. 4, allerdings mit dem 20 mm starken Nähgut;

Fig. 7

in einer zu den Fig. 3 und 4 ähnlichen Darstellung die Hüpfermechanik und die Nadelstangenmechanik in einer Momentanposition zwischen den Positionen nach den Fig. 3 und 4 mit dem Drückerfuß beim Erreichen einer unteren Position, dem Transportfuß weiterhin in einer unteren Position und der Nadelstange zwischen einer unteren und einer oberen Position relativ zur Auflageplatte; und

Fig. 8

die Hüpfermechanik und die Nadelstangenmechanik in einer Stangenstellung nach Fig. 7, allerdings mit dem 20 mm starken Nähgut.

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

Fig. 1

a side view of a sewing machine from the perspective of an operator;

Fig. 2

an exploded view of a Hüpfermechanik and a needle bar mechanism of the sewing machine;

Fig. 3

the hopping mechanics and the needle bar mechanism Fig. 2 in assembled form, shown with a fabric of 2 mm thickness, with a presser foot in an upper position, a transport foot in a lower position and the needle bar in a lower position relative to a support plate;

Fig. 4

in one too Fig. 3 similar illustration of the Hüpfermechanik and the needle bar mechanism with the presser foot in a lower position, the transport foot in an upper position and the needle bar in an upper position relative to the fabric support plate;

Fig. 5

the Hüpfermechanik and the needle bar mechanism in a rod position, according to those FIG. 3 corresponds, however, with a sewing material with 20 mm thickness;

Fig. 6

the hopping mechanism and the needle bar mechanism in a rod position Fig. 4 , but with the 20 mm thick fabric;

Fig. 7

in one of the Fig. 3 and 4 similar illustration the hopping mechanism and the needle bar mechanism in a momentary position between the positions after the Fig. 3 and 4 with the presser foot on reaching a lower position, the transport foot further in a lower position and the needle bar between a lower and an upper position relative to the support plate; and

Fig. 8

the hopping mechanism and the needle bar mechanism in a rod position Fig. 7 , but with the 20 mm thick material.

The in the Fig. 1 shown sewing machine 1 comprises a housing-like base plate 2, an upper arm 3 and a stand connecting them 4. The sewing machine 1 is thus formed a total of approximately C-shaped. In the arm 3, an arm shaft 5 is mounted, via which a needle bar 6 with a needle 7 by means of a crank drive, not shown in detail up and down driven. Of the arm shaft 5 is mounted via a belt drive 8 and a bearing in the base plate 2 shaft 9 mounted in the base plate 2 and the needle 7 associated gripper, which is also not shown in detail. Cooperating with the needle bar movement, the gripper motion, as is known, results in seaming in a stitch area.

A flange portion 10 is arranged on the arm shaft 5 at the level of the belt drive 8. About the flange portion 10, the arm shaft 5 is rotatably connected to a purpose aligned drive shaft 11 of a arm shaft drive motor 12. Adjacent to the flange portion 10, the drive shaft 11 is supported via an axial / radial bearing 12 a. On a free end 13 of the drive shaft 11, a handwheel 14 is attached and rotatably connected via a radial screw, not shown, connected to the drive shaft 11.

The sewing machine 1 is designed for sewing resistant and / or strong sewing material, in particular for sewing leather, very strong cloth material and / or also of plate-like material, for example of plastic plates.

The components of the sewing machine 1 are carried and supported by a frame 15 of the sewing machine 1, of which the base plate 2 is a part. Part of the base plate 2 is further a fabric support plate 16, which in turn is partially formed by a throat plate 17. In the area of the throat plate 17 is located on the support plate 16 sewing material 18 (see. Fig. 2 ) in a stitch formation area. In this, the sewing needle 7 cooperates with other sewing tools, so for example with the gripper, for seam formation.

Fig. 2 shows in an exploded view details of a Hüpfermechanik 19 and a needle bar mechanism 19a. The Hüpfermechanik 19 is connected to a transport foot 20 (see. Fig. 3 ) and a presser foot 21 for the alternate, jumping lifting and lowering on the one hand the transport foot 20 and on the other hand the presser foot 21 connected relative to the throat plate 17. The needle bar mechanism 19a is connected to the needle bar 6 and is part of an otherwise not shown needle bar drive for needle transport of the fabric 18th

To facilitate positional relationships, a Cartesian xyz coordinate system is used below. The x-direction runs in the Fig. 1 to the right. The y-direction is perpendicular to the plane of the Fig. 1 into this. The z-direction runs in Fig. 1 up. The arm shaft 5 is parallel to the x direction. The z-axis is perpendicular to the support plate 16th

The transport foot 20 is attached to a transporting foot bar 22 and cooperatively cooperates with the sewing needle 7 for transporting the work cloth 18 along a transporting direction T extending in the positive y-direction.

The presser foot 21 is attached to a presser foot bar 23 and serves to clamp the work cloth 18 on the throat plate 17 during a hold period within one stitching period of the sewing machine 1.

About a Hüpferglied 24, the Hüpfermechanik 19 is articulated on the Transportfußstange 22, on the presser foot rod 23 and on a Hüpferantrieb 25. The Hüpfermechanik 19 is designed as a triangular lever mechanism with triangular lever as the Hüpferglied 24. About a first joint with hinge pin 26 of the triangle lever 24 is articulated to a Transportfußhebel 27 which is articulated via a transport foot joint 28 on the Transportfußstange 22. About a second joint with a hinge pin 29 of the triangle lever 24 is hinged to the presser foot rod 23. Between the Hüpferglied 24 and the hinge pin 29 is still a washer 29a arranged. Via a third joint with a hinge pin 30 and a sliding block 31, the triangular lever 24 is articulated to a drive member 32 of the hoppers 19. The drive member 32 transmits a drive movement of the hüpferantriebs 25 on the triangle lever 24. The drive member 32 is designed as Gleitnutplatte with a sliding groove 33 , which is also referred to as a linear guide. The sliding groove 33 extends on the viewer of the FIGS. 2 to 6 facing away from Gleitnutplatte 32. The sliding groove 33 is in the Figures 2 and 3 indicated by dashed lines. The sliding groove 33 extends approximately parallel, so at most at a small angle to the z-axis.

The articulation of the Hüpfergliedes 24, so the triangular lever, with the Hüpferantrieb 25 via the drive member 32, so the Gleitnutplatte is due to the sliding or guide groove 33 designed such that depending on the thickness of the material 18, so depending on the thickness dependent, a relative displacement the Transportfußstange 22 and the presser foot rod 23 on the one hand to the drive member 32 on the other hand along a displacement path V (see the double arrow in the Fig. 2 and the arrows in the Figures 3 and 5 ) takes place perpendicular to the support plate 16 and the needle plate 17 without driving operation of the Hüpfergliedes 24 by the Hüpferantrieb 25.

To complete the Hüpferantriebsverbindung the drive member 32 has a drive joint with hinge pins 34, via which a gear drive lever of the Hüpferantriebs 25 in the form of a presser foot lever 35 is hinged to the drive member 32. The presser foot lever 35 is non-rotatably connected to a presser foot shaft 36. The presser foot shaft 36 constitutes a hoppers drive shaft. The presser foot shaft 36 is driven via a pusher foot gear 37, which is also referred to as a Hüpfergetriebe. About the presser foot 37, a Hüpferhub the Hüpferantriebs 25th be specified. This is done via the rotational position of a gearbox adjustment shaft 38 of the presser foot gear 37. Via an eccentric connection 39 and a pull rod 40, the presser foot gear 37 is in operative connection with the arm shaft 5, which is in Fig. 2 indicated by dashed lines. The presser foot gear 37 is a plate-type transmission with a plurality of gear lugs 41. The mode of operation of such a plate gear is described using the example of a stitch actuator transmission in FIG EP 2 330 241 A1 ,

With the presser foot gear 37 is a stepless specification of a Hüpferhubes a Hüpferbewegung the Transportfußstange 22 and the presser foot 23 is possible.

The drive member 32, so the Gleitnutplatte is hingedly connected to a frame lever 43 via another joint with hinge pin 42. The latter is connected via another joint with hinge pin 44 with the frame 15 of the sewing machine 1, which in Fig. 2 is indicated. This articulation of the frame lever 43 on the frame 15 simultaneously represents a point of articulation for a needle bar frame 45 which is part of the needle bar mechanism 19a. The Nadelstangerahmen 45 has a guide sleeve portion 46 in which the needle bar 6 and the Transportfußstange 22 are guided. For transporting the sewing material 18, the needle bar frame 45 is pivoted about a needle bar drive, not shown, about a hinge axis predetermined by the hinge pin 44, which runs parallel to the x-axis. The hinge pin 44 provides a pivot point on the one hand for the needle bar frame 45 and on the other hand for the frame lever 43.

The presser foot lever 35 on the one hand and the frame lever 43 on the other hand, together with the drive member 32, form a parallelogram arrangement.

A bias of the presser foot rod 23 toward the throat plate 17 is predetermined via an adjusting screw 47 which acts on the presser foot rod 23 via a biasing spring 48.

In the exploded view to Fig. 2 are still several joint retaining clips 49 for axially play-free joint connection shown.

Fig. 3 shows the Hüpfermechanik 19 and the needle bar mechanism 19a in a rod-relative position, in which the pusher bar 23 in an upper position, the Transportfußstange 22 are shown in a lower and also the needle bar 6 in a lower position. In this position, the transport foot 20 clamps the sewing material 18 onto the throat plate 17, so that the sewing material 18 can be transported safely.

The sewing material 18 has in the representation of the rod relative positions after the Figures 3 and 4 a thickness of 2 mm.

Due to the relatively thin fabric 18 Transportfußstange 22 is in their in the Fig. 3 shown lower position far in the negative z-direction to the throat plate 17 to lowered. This has no effect on the Hüpferhub the Hüpfermechanik 19, since the Hüpferglied 24 relative to the drive member 32 can move in the negative z-direction with the Transportfußstange 22 and the presser foot rod 23 (see arrow V in Fig. 3 ). Fig. 5 shows the in Fig. 3 corresponding rod relative position of the transport bar 22 of the presser foot rod 23 and the needle bar 6 at very thick material 18 '. The fabric 18 'has a thickness of 20 mm. Accordingly, the transport foot 20 in its lower, the fabric 18 'clamping position after Fig. 5 in comparison to the position after Fig. 3 shifted by a significant amount in the positive z-direction. The articulation of the Hüpfergliedes 24 with the drive member 32 can compensate for this, since the Hüpferglied 24 due to the straight guide on the sliding groove 33 in the positive z-direction (see arrow V in Fig. 5 ) can relocate.

The thickness of the material to be sutured 18, 18 'thus has virtually no influence on the Hüpferbewegung and in particular virtually no influence on the Hüpferhub the Transportfußes 20 and the presser foot 21. Even with very thin material, for example, the fabric 18 or very thick material, for example, the fabric 18 ', the transport foot 20 and the presser foot 21 can be driven in the same way by the hüpferantrieb 25 for hopping raising and lowering.

Fig. 4 shows the thin sewing material 18, the relative rod position with the presser foot rod 23 in the lower position in which the presser foot 21, the workpiece 18 is clamped on the needle plate 17, and with the Transportfußstange 22 and the needle bar 6 in an upper position.

The change of the relative positions on the one hand the Transportfußstange 22 and on the other hand the presser foot 23 between the Figures 3 and 4 is caused by the Hüpferantrieb 25 in conjunction with the Hüpfermechanik 19. Compared to Fig. 3 is in Fig. 4 the presser foot lever 35 pivots counterclockwise about the axis of the presser foot shaft 36, so that the entire parallelogram with the presser foot lever 35, the drive member 32 and the frame lever 43 has pivoted accordingly. The drive lever 32 takes on the compound of the sliding groove 33 with the hinge pin 30 via the sliding block 31, the triangle lever, so the hopper member 24 and pivots this also counterclockwise. This causes, compared to Fig. 3 in Fig. 4 the presser foot rod 23 is lowered and the transport foot bar 22 is raised.

The Figures 5 and 6 again show the change between the rod relative positions "pusher bar 23 above, transport bar 22 below and needle bar 6 below" on the one hand (see. Fig. 5 ) and "presser rod 23 at the bottom, transport bar 23 at the top and needle bar 6 at the top" on the other hand (cf. Fig. 6 ). Due to the stronger Nähgut 18 'compared to the application in the Figures 3 and 4 is in the Figures 5 and 6 the hopping member 24, so the triangle lever, relative to the drive member 32, ie relative to Gleitnutplatte, displaced in the positive z-direction (see arrow "V" in Fig. 5 ). On the principle of the parallelogram drive, which the hüpferantrieb 25 via the drive member 32 on the Hüpferglied 24 exercises, this does not change. Thus, it remains with one of the workpiece uninfluenced hopping movement of the presser foot rod 23 and the Transportfußfuß 22nd

In an alternative embodiment, not shown, a guide or sliding groove 33 may also be performed on the triangle lever 24 in the manner of the sliding groove 33. In this alternative embodiment, a hinge pin, in particular with a sliding block, then arranged on the drive member 32.

Fig. 7 shows the thin sewing material 18, the relative rod position with the presser foot rod 23 when reaching the lower position, with the Transportfußstange 22 continues in the lower position and with the needle bar 6 between the lower position after Fig. 3 and the upper position Fig. 4 ,

Fig. 8 shows the thick material to be sewn 18 ', the relative rod position corresponding to Fig. 7 ,

Claims (7)

1. Sewing machine (1) comprising

   - a frame (15)

   - a fabric support plate (16),

   - a needle bar (6) with a sewing needle (7), which operates in a stitch forming area with other sewing parts to form a seam,

   - a transport foot (20) attached to a transport foot bar (22) used for transporting fabric (18; 18') along a transport direction (T),

   - a presser foot (21) attached to a presser foot bar (23) used for clamping the fabric (18; 18') onto the support plate (16) during a holding time within a stitch forming period,

   - a hopper mechanism (19) connected to the transport foot (20) and the presser foot (21) for alternate hopping lifting and lowering on the one hand of the transport foot (20) and on the other hand of the presser foot (21) relative to the support plate (16),

   - wherein the hopper mechanism (19) is coupled via a hopper element (24) to the transport bar (22), the presser foot bar (23) and a hopper drive (25),

   - wherein a joint connection of the hopper element (24) with the hopper drive (25) via a drive element (32) is configured with a guiding groove (33) such that depending on the thickness of the fabric a relative displacement of the transport foot bar (22) and the presser foot bar (23) on the one hand to the drive element (32) on the other hand is performed along a displacement path (V) perpendicular to the support plate (16) without the drive activation of the hopper element (24),

   - wherein the drive element (32) is connected via a frame lever (43) to the frame (15).
2. Sewing machine according to claim 1, characterized in that the hopper mechanism (19) is configured as a triangular lever mechanism with a triangular lever as a hopper element (24), which is coupled

   - via a first joint (26) to the transport foot bar (22),

   - via a second joint (29) to the presser foot bar (23),

   - via a third joint (30) to the drive element (32).
3. Sewing machine according to claim 1 or 2, characterized in that the drive element (32) is configured as a sliding groove plate, in the sliding guiding groove (33) of which a guiding bolt (30) of the hopper element (24) is guided.
4. Sewing machine according to claim 3, characterized in that the guiding bolt (30) is guided in the sliding guiding groove (33) via a slide block (31).
5. Sewing machine according to one of claims 1 to 4, characterized in that the drive element (32) is connected via a gear lever (35) and a hopper drive shaft (36) to a hopper gear (37), by means of which a hopper lift of the transport foot bar (22) and the presser foot bar (23) can be provided.
6. Sewing machine according to one of claims 1 to 5, characterized in that the needle bar (6) for fabric needle transport can be pivotably driven by a needle bar frame (45), which is connected via a needle bar frame coupling point (44) to the frame (15).
7. Sewing machine according to claim 6, characterized in that the frame lever (43) is coupled to the frame (15) by means of the needle bar frame coupling point (44).

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