TWI595134B - Sewing machine - Google Patents

Description

Sewing machine Cross-reference to related applications

The content of the German patent application DE 10 2012 207 257.8 is incorporated herein by reference.

Technical field

The present invention relates to a sewing machine, and more particularly to a heavy duty sewing machine, i.e., a sewing machine for forming stitches on a very strong or very thick fabric.

Background of the invention

Many different embodiments of sewing machines, particularly heavy duty sewing machines, are known.

Summary of invention

It is an object of the invention to develop a sewing machine with a hopper mechanism that is connected to a conveying foot for conveying a fabric and a presser foot for clamping the fabric so that they are alternately fed relative to the support plate The ascending and descending movements are such that during operation the feed mechanism is substantially unaffected by the thickness of the fabric.

According to the invention, the object is achieved by a sewing machine, the seam The machine includes: - a frame, a fabric support plate, a needle bar with an organic needle, the needle stitch formation area working with other sewing parts to form a seam, - a delivery foot attached to the delivery foot, which The conveying foot is for conveying the fabric in the conveying direction, - a presser foot attached to the presser foot for clamping the fabric on the support plate during the holding time during the stitch forming phase, - feeding a mechanism, the feed mechanism being coupled to the delivery foot and the presser foot for raising and lowering the alternate feed of the presser foot relative to the support plate on the one hand - Wherein the feed mechanism is coupled to the delivery foot, the presser foot and the feed drive via a feed element, wherein the engagement of the feed element with the feed drive via the drive element utilizes guidance The groove is configured such that, in the absence of drive actuation of the feed element, the delivery foot and the presser foot can be made on the one hand with respect to the drive element and on the other hand depending on the thickness of the fabric the To straight displacement path of the support plate relative displacement is performed, - wherein said drive element is connected to the frame via a lever frame.

According to the invention, the joint connection between the feed element and the feed drive via the drive element having the guide groove ensures that the thickness or strength of the fabric to be formed does not affect the feed of the feed foot and the presser foot move. Even if a very thin fabric or a very thick fabric is treated, the feed foot and the presser foot can be driven by the feed drive in the same manner for feed rise and feed drop. A guide groove of the feed element and the feed connection of the feed drive may be formed on the drive element or formed on the feed element. The frame lever connection in which the drive element is connected to the frame via the frame lever ensures a firm coupling of the drive element.

The feed mechanism is configured as a delta lever mechanism having a triangular lever as a feed element: - coupled to the delivery foot via a first engagement piece, - coupled to the presser foot via a second engagement piece - coupled to the drive element via a third joint.

Such a feeding mechanism can be formed to be compact with fewer mechanical parts.

In a robust variant of the drive element, the drive element is embodied as a sliding groove plate, and the guide bolts (pins, latches) of the feed element are guided in the sliding guide grooves of the sliding groove plate.

The guiding bolt can be guided in the sliding guide groove via the sliding block, which avoids distortion in the region of the guiding groove and reduces wear.

The drive element is connected via a transmission lever and a feed drive shaft to a feed drive (gear) by means of which the feed lift (rise, lift) of the feed foot and the presser foot can be provided. The feed drive makes it possible to adjust the feed drive according to the respective sewing requirements. The feed gear can be driven by means of the arm shaft of the sewing machine, from which the movement of the other sewing parts, in particular the needle bar, can also be achieved. By means of the feed gear, the feed lift can be particularly continuous. Drive unit The piece is connected to the frame by means of a frame lever which can form a parallelogram configuration with the transmission lever according to the invention. This parallelogram configuration is stable.

A needle bar for fabric needle delivery can be pivotally driven by a needle bar frame that is coupled to the frame via a needle bar frame coupling point. The needle bar frame that can be pivotally driven can be reliably used to transport fabric. This fabric needle delivery can be set to synchronize with the movement of the delivery foot.

The frame lever is coupled to the frame by means of a needle bar frame coupling point. The coupling of such a frame lever makes the structure compact. There is thus no need for a separate frame holder for the drive element.

1‧‧‧ sewing machine

2‧‧‧Substrate

3‧‧‧ top arm

4‧‧‧ column

5‧‧‧Bear axis

6‧‧‧ Needle bar

7‧‧‧ needle

8‧‧‧With gearing

9‧‧‧Axis

10‧‧‧Flange

11‧‧‧Drive shaft

12‧‧‧Bear shaft drive motor

12a‧‧‧diameter/axial bearings

13‧‧‧Free end

14‧‧‧Handwheel

15‧‧‧Frame

16‧‧‧support plate

17‧‧‧track board

18, 18’‧‧‧ fabric

19‧‧‧Feeding agency

19a‧‧‧Needle bar mechanism

20‧‧‧ delivery foot

21‧‧‧Foot presser

22‧‧‧ delivery foot

23‧‧‧ Presser foot

24‧‧‧Feeding element/triangle lever

25‧‧‧Feed drive

26, 29, 30, 34, 44‧‧‧ joint bolts

27‧‧‧Transport foot lever

28‧‧‧Transport foot joints

29a‧‧‧ Washer

31‧‧‧Sliding block

32‧‧‧Drive components / sliding slot

33‧‧‧ Guide slot/sliding slot

35‧‧‧Foot lever

36‧‧‧Pressure foot shaft

37‧‧‧Foot foot transmission

38‧‧‧Transmission adjustment shaft

39‧‧‧Eccentric connectors

40‧‧‧ tension bar

41‧‧‧Gear tab

42‧‧‧Joint bolt

43‧‧‧Frame lever

45‧‧‧ Needle bar frame

46‧‧‧ Guide sleeve part

47‧‧‧Adjustment bolts

48‧‧‧Prestressed spring

49‧‧‧Joint holding clamp

T‧‧‧ conveying direction

V‧‧‧Transition path

Exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings: Figure 1 shows a side view of the sewing machine as seen from the perspective of the operator; Figure 2 shows an exploded view of the feeding mechanism and the needle bar mechanism of the sewing machine; Figure 3 shows the assembled form according to Figure 2 Feeding mechanism and needle bar mechanism, wherein the thickness of the fabric is 2 mm, the presser foot is at a higher position, the conveying foot is at a lower position, and the needle bar is at a lower position relative to the support plate; FIG. 4 is similar to FIG. The view shows the feed mechanism and the needle bar mechanism, wherein the presser foot is in a lower position, the transport foot is in a higher position, the needle bar is in a higher position relative to the fabric support plate; FIG. 5 is shown in accordance with FIG. a feeding mechanism and a needle bar mechanism in a rod position corresponding to a position but having a fabric thickness of 20 mm; FIG. 6 shows a rod position in a fabric thickness of 20 mm according to FIG. Feeding mechanism and needle bar mechanism in the middle; FIG. 7 shows the feeding mechanism and the needle bar mechanism in the current position between the position according to FIG. 3 and the position according to FIG. 4 in a view similar to FIGS. 3 and 4. Wherein the presser foot reaches a lower position, the transport foot is also in a lower position, the needle bar is in a position between a lower position and a higher position relative to the support plate; and FIG. 8 shows the fabric thickness according to FIG. Feed mechanism and needle bar mechanism in a 20 mm rod position.

Detailed description of the preferred embodiment

The sewing machine 1 shown in Fig. 1 comprises a shell-like substrate 2, a top arm 3 and a column 4 connecting the top arm. The sewing machine 1 is thus constructed in a C shape as a whole. An arm shaft 5 is mounted in the arm 3, by means of which the needle bar 6 with the needle 7 can be driven up and down via a crank drive, not shown in detail. By means of the arm shaft 5 via the belt drive 8 and the shaft 9 mounted in the base plate 2, the clamping member mounted in the base plate 2 and assigned to the needle 7 is driven, which is also not shown in detail. The known needle bar motion works simultaneously with the movement of the clamp so that the stitch area forms a seam.

The flange portion 10 is disposed on the arm shaft 5 at the position of the belt transmission 8. By means of the flange portion 10, the arm shaft 5 is non-rotatably connected to the drive shaft 11, wherein the drive shaft 11 is aligned with the arm shaft drive motor 12. The drive shaft 11 is mounted by a radial/axial bearing 12a near the flange portion 10. The hand wheel 14 is mounted to the free end 13 of the drive shaft 11 and is non-rotatably coupled to the drive shaft 11 via a radial screw, not shown.

The sewing machine 1 is arranged to sew thick and/or sturdy fabrics, in particular for sewing leather, very thick cloth and/or board materials, such as plastic sheets.

The components of the sewing machine 1 are supported and mounted by the frame 15 of the sewing machine 1, and the substrate 2 is a part of the frame. A portion of the substrate 2 is also a fabric support panel 16, which is formed in part by the track panel 17. In the area of the track trace 17, the fabric 18 rests on the support plate 16 in the track formation area (refer to Fig. 2). In the track forming area, the needle 7 works with other sewing members, such as grips, to form a seam.

Figure 2 shows an exploded detail view of the feed mechanism 19 and the needle bar mechanism 19a. The feeding mechanism 19 is connected to the conveying foot 20 (refer to FIG. 3) and the presser foot 21 for alternate feeding rise and fall of the conveying foot 20 and the presser foot 21 with respect to the stitch plate 17. The needle bar mechanism 19a is coupled to a needle bar 6 which is also part of a needle bar drive for needle transport of the fabric 18, not shown.

In order to simplify the relative position, a Cartesian xyz coordinate system is used hereinafter. The x-direction points to the right side of Figure 1. The y-direction is perpendicular to the drawing paper of Figure 1 facing inward. The z-direction points to the top of Figure 1. The arm shaft 5 extends parallel to the x-direction. The z-axis is perpendicular to the support plate 16.

The delivery foot 20 is attached to the delivery foot 22 and is used with the needle 7 to transport the fabric 18 in the transport direction T, which is in the positive y-direction.

The presser foot 21 is attached to the presser foot bar 23 and is used to clamp the fabric 18 onto the stitch plate 17 during the holding time of the stitch forming phase of the sewing machine 1.

The feed mechanism 19 is coupled to the delivery foot 22, the presser foot 23 and the feed drive 25 by means of the feed element 24. The feed mechanism 19 is constructed as a delta lever mechanism with a triangular lever as the feed element 24. By means of a first engagement element with an engagement bolt 26, the delta lever 24 is coupled to a delivery foot lever 27, which is coupled to the delivery foot by means of a delivery foot engagement member 28. Rod 22. The triangular lever 24 is coupled to the presser foot 23 by means of a second engagement member with an engagement bolt 29. A washer 29a is also disposed between the feed element 24 and the joint bolt 29. The triangular lever 24 is coupled to the drive element 32 of the feed mechanism 19 by means of a third engagement member with an engagement bolt 30 and a slider 31. The drive element 32 transmits the drive motion of the feed drive 25 to the delta lever 24. The drive element 32 is configured as a sliding slot plate with a sliding slot 33 as indicated by the dashed line. The sliding groove 33 extends along a side of the sliding groove plate 32 that faces away from the observer of FIGS. 2 to 6. The sliding groove 33 is shown by a broken line in FIGS. 2 and 3. The sliding groove 33 extends substantially parallel to the z-axis, that is, may be at a small angle to the z-axis.

The connection of the feed element 24, ie the delta lever, to the feed drive 25 via the drive element 32, ie the sliding slot plate, is based on the sliding or guide groove 33 so that the thickness of the fabric 18 can be determined, ie the thickness of the fabric Accordingly, in the case where the feed member 24 is not actuated via the feed drive device 25, there are the transfer leg 22 and the presser bar 23 with respect to the drive member 32 and along the displacement path V (refer to the double arrow in FIG. 2, 3 and the relative displacement of the arrow in FIG. 5, which is perpendicular to the support plate 16 and perpendicular to the track plate 17.

In order to complete the feed drive connection, the drive element 32 has a drive engagement with a coupling bolt 34 by means of which the gear drive lever of the feed drive 25 is coupled to the drive in the form of a presser foot lever 35 Element 32. The presser foot lever 35 is non-rotatably coupled to the presser foot shaft 36. The presser foot shaft 36 represents a feed drive shaft. The presser foot shaft 36 is driven by a presser foot drive 37, also referred to as a feed drive. The feed lift of the feed drive 25 can be limited by means of the presser foot drive 37. This is achieved by means of the rotational position of the drive adjustment shaft 38 of the presser foot drive 37. With the help of The eccentric link 39 and the tensioning lever 40 are operatively coupled to the arm shaft 5 as shown by the dashed lines in FIG. The presser foot transmission 37 is a tab gear having a plurality of gear tabs 41. The operation of such a sheet-type transmission is described by taking a stitch-adjusting transmission as an example in EP 2 330 241 A1.

By means of the presser foot drive 37, the feed lift of the feed motion of the feed foot 22 and the presser foot 23 can be continuously performed.

The drive element 32, ie the sliding slot plate, is connected to the frame lever 43 via another engagement piece with an engagement bolt 42. The frame lever 43 is connected to the frame 15 of the sewing machine 1 shown in Fig. 2 via another engaging member with a joint bolt 44. The engagement connection of the frame lever 43 with the frame 15 is also the connection point for the needle bar frame 45 as part of the needle bar mechanism 19a. The needle bar frame 45 includes a guiding sleeve portion 46 in which the needle bar 6 and the delivery foot bar 22 are guided. To convey the fabric 18, the needle bar frame 45 is pivoted about an engagement shaft via a needle bar drive, not shown, which is provided by engagement bolts 44 that extend parallel to the x-axis. Engagement bolts 44 provide a coupling point for the needle bar frame 45 and for the frame lever 43.

The presser foot lever 35 and the frame lever 43 together with the drive member 32 form a parallelogram configuration.

The pretensioning of the presser foot bar 23 towards the track plate 17 takes place by means of an adjusting bolt 47 which acts on the presser foot bar 23 via a prestressing spring 48.

In the exploded view according to Fig. 2, a further engagement retaining clamp 49 for the axial gapless joint connection is also shown.

Figure 3 shows the feed mechanism 19 and the needle bar mechanism 19a in the relative position of the rod, wherein the presser foot 23 is shown in a higher position and the delivery foot 22 is shown It is in the lower position and the needle bar 6 is also in the lower position. The delivery foot 20 clamps the fabric 18 to the stitch plate 17 at this location to enable the fabric 18 to be reliably transported.

In the view of the relative position of the rod according to Figures 3 and 4, the fabric 18 has a thickness of 2 mm.

Because of the thinner fabric 18, the delivery foot 22, shown in Fig. 3 as being in the lower position, descends further in the negative z-direction and onto the track plate 17. This does not affect the feed lift of the feed mechanism 19 because the feed element 24 can be displaced with the delivery foot 22 and the presser foot 23 in the negative z-direction relative to the drive element 32 (see arrow V of Figure 3).

Figure 5 shows the relative rod position according to Figure 3 of the delivery foot 22 and the presser foot 23 and the needle bar 6, with a very thick fabric 18'. The fabric 18' has a thickness of 20 mm. Thus, the delivery foot 20 in the lower position and gripping the fabric 18' according to Figure 5 is displaced by a substantial amount of displacement in the positive z-direction as compared to the position of Figure 3. The engagement connection of the feed element 24 with the drive element 32 can counteract this amount of displacement because the feed element 24 can be displaced in the positive z-direction due to the linear guidance of the sliding groove 33 (refer to arrow V in Figure 5).

The thickness of the fabrics 18, 18' hardly affects the feeding motion, and in particular, the feed lift of the conveying foot 20 and the presser foot 21 is hardly affected. Even if a very thin fabric such as a treated fabric 18 is treated, or a very thick fabric such as fabric 18' is treated, the feed foot 20 and the presser foot 21 can be driven in the same manner by the feed drive unit 25 to effect the feed rise and fall.

Figure 4 shows the relative rod position in the case of a thin fabric 18 with the presser foot 23 in a lower position - in which position the presser foot 21 clamps the fabric 18 to the line track 17 is on, while the delivery foot 22 and the needle bar 6 are in a higher position.

The relative position of the delivery foot 22 and the relative position of the presser foot 23 are changed between FIGS. 3 and 4 by the feed drive member 25 connected to the feed mechanism 19. In contrast to FIG. 3, in FIG. 4, the presser foot lever 35 pivots counterclockwise about the axis of the presser foot shaft 36 to cause the entire parallelogram including the presser foot lever 35, the drive member 32 and the frame lever 43 to pivot accordingly. By means of the sliding groove 33 and the connection of the coupling bolt 30 via the sliding block 31, the drive lever 32 carries a triangular lever, ie the feed element 24, and pivots the feed element 24 counterclockwise. This means that in comparison with FIG. 3, in FIG. 4, the presser foot bar 23 is lowered and the transport foot bar 22 is raised.

Figures 5 and 6 show the change between the two relative rod positions, one of which is "the presser foot 23 is on, the delivery foot 22 is down, the needle bar 6 is down" (refer to Figure 5), A relative rod position is "the presser foot 23 is down, the transfer foot 22 is on, and the needle bar 6 is up" (refer to Figure 6). Because the fabric 18' in Figures 5 and 6 is thicker than the fabric of Figures 3 and 4, the feed element 24, i.e., the triangular lever, is positively z-phase relative to the drive member 32, i.e., relative to the sliding slot plate. Directional displacement (see arrow "V" in Figure 5). Due to the principle of the parallelogram, there is no change in the drive of the feed drive 25 applied to the feed element 24 via the drive element 32. Therefore, the feeding motion of the presser foot bar 23 and the transport foot bar 22 is not affected by the fabric.

In an alternative embodiment not shown, a guiding or sliding groove similar to the sliding groove 33 may also be formed on the triangular lever 24. In this alternative embodiment, the joint bolts, in particular with the sliding blocks, are arranged on the drive element 32.

Figure 7 shows the relative rod position in the case of a thin fabric 18, wherein the presser foot 23 reaches a lower position, the transport foot 22 further reaches a lower position, the needle bar 6 is in the lower position according to Figure 3 and according to Figure 4 Between higher positions.

Figure 8 shows the relative rod position according to Figure 7 in the case of a thick fabric 18'.

5‧‧‧Bear axis

6‧‧‧ Needle bar

7‧‧‧ needle

15‧‧‧Frame

17‧‧‧track board

18‧‧‧ fabric

19‧‧‧Feeding agency

19a‧‧‧Needle bar mechanism

20‧‧‧ delivery foot

21‧‧‧Foot presser

22‧‧‧ delivery foot

23‧‧‧ Presser foot

24‧‧‧Feeding element/triangle lever

25‧‧‧Feed drive

26, 29, 30, 34, 44‧‧‧ joint bolts

27‧‧‧Transport foot lever

28‧‧‧Transport foot joints

29a‧‧‧ Washer

31‧‧‧Sliding block

32‧‧‧Drive components / sliding slot

33‧‧‧ Guide slot/sliding slot

35‧‧‧Foot lever

36‧‧‧Pressure foot shaft

37‧‧‧Foot foot transmission

38‧‧‧Transmission adjustment shaft

39‧‧‧Eccentric connectors

40‧‧‧ tension bar

41‧‧‧Gear tab

42‧‧‧Joint bolt

43‧‧‧Frame lever

45‧‧‧ Needle bar frame

46‧‧‧ Guide sleeve part

47‧‧‧Adjustment bolts

48‧‧‧Prestressed spring

49‧‧‧Joint holding clamp

T‧‧‧ conveying direction

Claims (7)

A sewing machine comprising: a frame-fabric support plate, a needle bar having an organic needle, the needle stitch forming area working together with other sewing parts to form a seam, and being attached to the conveying foot a conveying foot on the rod for conveying the fabric in the conveying direction, - a presser foot attached to the presser foot for clamping the fabric during the holding time during the stitch forming phase a support mechanism on the support plate, the feeding mechanism being connected to the conveying leg and the pressing foot for raising and lowering the feeding foot and the alternate feeding of the pressing foot with respect to the supporting plate, wherein The feed mechanism is coupled to the feed foot, the presser foot and the feed drive via a feed element, wherein the feed element and the feed connection of the feed drive via the drive element are configured with a guide groove, Thereby the displacement of the transport foot and the presser foot relative to the drive element and along the vertical direction of the support plate can be performed without depending on the thickness of the fabric without the drive actuation of the feed element Relative displacement path, - wherein the driving element is connected to the frame via a lever frame. The sewing machine according to claim 1, wherein the feeding mechanism is configured as a triangular lever mechanism, and the triangular lever mechanism has There is a triangular lever as a feed element: - coupled to the delivery foot via a first engagement piece, - to the presser foot via a second engagement piece, - coupled to the base via a third engagement piece Drive element. The sewing machine according to the first aspect of the invention is characterized in that the driving element is configured as a sliding groove plate, and the guiding bolt of the feeding member is guided in a sliding guiding groove of the sliding groove plate. The sewing machine according to the third aspect of the invention is characterized in that the guide bolt is guided in the sliding guide groove via a slide block. A sewing machine according to the first aspect of the invention, characterized in that the drive element is connected to a feed transmission via a transmission lever and a feed drive shaft, by means of which the delivery foot and the Feed lift of the presser foot. A sewing machine according to claim 1, wherein the needle bar for fabric needle transport is pivotally driven by a needle bar frame, the needle bar frame being coupled to the needle rod frame coupling point frame. A sewing machine according to claim 6, wherein the frame lever is coupled to the frame by means of a needle bar frame coupling point.