JP2004081855A - Buttonhole sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a buttonhole sewing machine being simple in its design and comprising a thread drawing-out device free from troubles in operation. <P>SOLUTION: This buttonhole sewing machine for making buttonhole stitch on a workpiece comprises a guide 12 for feeding a looper thread 14 and maybe a guimp thread, and a thread drawing-out device 27 mounted in a feed traveling passage, the thread drawing-out device comprises a plurality of first ribs 28 mounted along the feed traveling passage at intervals to each other, and a plurality of second ribs 29 mounted at intervals to each other, movable toward the first ribs 28, and insertable between the first ribs 28, whereby the looper thread 14 and maybe the guimp thread can be drawn out in a state of being bent. The first ribs 28 are properly mounted on a cover 25 of a sewing machine. <P>COPYRIGHT: (C)2004,JPO

Description

(4) The present invention relates to a buttonhole sewing machine for forming a buttonhole seam in a processed product.

Patent Literature 1 (corresponding to Patent Literature 2) describes a buttonhole sewing machine having a bottom plate, a top arm, and a column connecting the bottom plate and the arm, particularly an eyelet-shaped (eye) buttonhole sewing machine. Further, the buttonhole sewing machine has a needle bar provided with a needle and housed in an arm, and the needle bar can be driven so as to reciprocate up and down by a main drive motor. The hole sewing machine further has a clamp for holding the workpiece. A hook for delivering a looper thread is provided on the bottom plate. A guide is provided for feeding the looper yarn to the hook along the movement path, and a yarn pulling device is disposed in the looper yarn movement path. The thread puller has a suction device that cooperates with a vacuum generator to taut the looper thread tail between two buttonhole stitching operations. A disadvantage of this known device is that only very short lengths of looper yarn can be pulled out.
German Patent No. 4110684 U.S. Pat. No. 5,156,103

Non-Patent Document 1 describes an electro-pneumatically operated thread pulling device for an eye-shaped buttonhole sewing machine, and uses this device to separate a looper thread from a bobbin. A rotatable lever is provided, the end of which has an eyelet for holding a looper thread. The lever is pivoted by a pneumatically actuated piston-cylinder drive, the operating speed of the lever being regulated via a throttle valve. The pulled out looper thread may be present in an uncontrolled exposed state, bare and possibly entangled, which may result in a malfunction of the sewing function. The pivot angle of the lever must be taken into account so that the required and desired length of the looper thread can be pulled out. When it comes to the fact that the lever has to rotate through a relatively wide angle, the design of the pneumatically operated piston-cylinder drive that acts on the lever must be dimensioned accordingly. On the one hand, the lever must be easily accessible for threading the looper thread. On the other hand, the lever must be encapsulated by a protective device to eliminate the risk of injury.
Durcop Adler Co., Ltd. brochure "Service Instructions 578" published on 03/98, component no. 0791 578037

An object of the present invention is to embody a buttonhole sewing machine provided with a thread pull-out device formed so as to simplify the design and operate without trouble.

According to the invention, this object is achieved by the features of claim 1. Since the looper yarn is tortuous when pulled out, there is no need for a long travel path for delivering the first and second ribs toward each other. If a sufficient number of ribs are used, a few millimeters will be sufficient. Insertion of the looper thread is easily feasible, wherein the looper thread is arranged in a straight line between the first and second ribs while the ribs are separated.

Claim 2 of course reflects a simple looper thread guide interrupted near the ribs. According to its embodiment according to the invention, a corresponding gimp thread guide can be provided substantially without the additional requirements specified in claims 3 and 4.

During the sewing operation, the first rib, which is normally stationary, can be arranged according to claim 5, but according to a further development according to claim 6, it is easily accessible, in particular the insertion of looper thread and possibly the gimp. Thread insertion is also very easy. The cover is a shield that protects the worker from being injured by the moving parts of the sewing machine. On the other hand, the cover ensures the simplicity of threading and ensures good access to the thread puller. Further, the cover has a function of closing the assembly hole of the column and a function of providing access to the assembly hole. The withdrawn thread is located in a closed space and is therefore shielded.

According to the embodiment of the second deliverable rib according to claims 7 to 10, a very simple, compact and reliable design is obtained.

The details of the present invention will become apparent from the following description of the exemplary embodiments with reference to the drawings.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The eye-shaped buttonhole sewing machine shown in the figure has a bottom plate 1 in the form of a casing and a top arm 2, both of which are joined by struts 3 such that the sewing machine has a general C shape. . The arm shaft 4 is housed in the arm 2 such that the arm shaft 4 can be driven by a main drive motor 5 disposed on the column 3 via a belt drive unit 6. It is conventionally driven by the arm shaft 4 so that the needle bar 7 having the needle 8 can be driven to reciprocate up and down.

A hook universal bearing 10 is rotatably arranged on the support 9 in the bottom plate 1 as usual, and the universal bearing 10 supports a hook 11 for holding a thread. Further, the hook universal bearing 10 is provided with a thread cutter 11 a arranged above the hook 11. A thread cutter of this type is described in DE 195 31 727 (corresponding to U.S. Pat. No. 5,647,290). The looper thread guide tube 12 and the gimp thread guide tube 13 are guided from the top of the support 3, through the support 3 and the bottom plate 1 to the vicinity of the hook 11, as can be seen especially in FIG. 2. Looper thread 14 is fed through looper thread guide tube 12 to hook 11, while gimp thread 15 can be delivered through gimp thread guide tube 13. The upper thread 16 usually comes from the top of the arm 2 and is supplied to the needle 8.

Mounted on the bottom plate 1 is a movable table 17 in the form of an xy table, on which there are two bearing levers 19, 19 'on which clamping plates 20, 20' are mounted. A workpiece clamp 18 is mounted, and the workpiece clamp 21 clamps the workpiece 21 to a support plate 22 mounted on the table 17. This design and the operation of this type of workpiece clamp 18 is described in DE-A-10216809.

On the rear part 24 of the sewing machine facing away from the operator side 23, the column 3 is closed by a cover 25, which is opened via a bottom hinge 26 which extends in the y-direction, i.e. horizontally. Can be closed or closed. Provided on the cover 25 and inside the strut 3 is a thread pull-out device 27 by means of which a sufficient amount of looper thread 14 and possibly gimp thread 15 are supplied prior to the start of the buttonhole sewing operation. Is also drawn out. When the cover 25 is closed, the device 27 has a fixed first rib 28 in the form of a cross section in the form of a comb. The device 27 further has a second dispensable rib 29 inserted between the ribs 28, by means of which the meandering thread pull-out passage 30 is formed by the ribs 28, 29. Made between and around the width a of the passage 30 and thus its overall length can be adjusted by the delivery range of the rib 29. This possibility of delivery is achieved by the fact that a rib 29 is mounted on the first lever arm 31 of a double-arm thread pull-out lever 32, which pulls a shaft 33 arranged in the y-direction. It is arranged on the column 3 so as to be rotatable about the center. The shaft 33 is located below the first lever arm 31. A linear drive 35 in the form of a pneumatically actuated piston-cylinder drive acts on a second lever arm 34 of the lever 32, which extends downwardly from the shaft 33. The cylinder 36 of the driving device 35 is firmly attached to the second lever arm 34. An air hose 37 opens into the cylinder 36. A piston 38 displaceable in the cylinder 36 leans against a rear wall 39 of the column 3. Compressed air from a source not shown enters the cylinder 36 through the pipe 37 via the solenoid operated valve 40 in the form of a 3/2 port directional control valve. The actuation of the valve 40 takes place via the central control system 41 of the sewing machine.

A set screw 42 is provided on the rear wall 39 above the shaft 33, and the set screw 42 rotates the first lever arm 31 toward the cover 25 when the driving device 35 is actuated by compressed air. The range to be set is set. In other words, the set screw 42 is used to adjust the depth at which the dispensable ribs 29 enter between the ribs 28, thereby determining the width a of the thread withdrawal passage 30. A pre-loaded compression spring 43 is disposed between the set screw 42 and the shaft 33 so that when the pressure of the driving device 35 is released to release the rib 29 from the rib 28, the first compression spring 43 is released. Is rotated.

Inside the top, the cover 25 is provided with two retaining springs 44, which, when the cover is closed, flexibly engage with the ribs 45 formed on the inner top of the column 3 when the cover is closed. I do.

In the embodiment of FIGS. 3 to 5, on the one hand the cover 25 and the rib 28 form a single piece, on the other hand the thread pull-out lever 32 and the rib 29 form a single piece, both of which For example, it is made of a hard elastic plastic material. The ribs 28 of the cover 25 are connected to each other by a side plate 46 extending in the z direction. These side plates 46 protrude beyond the ribs 28 in the direction of the thread pull-out lever 32.

In the alternative embodiment according to FIGS. 6 and 7, a hardened steel pin 47 is provided as a surface protector on the top of each of the ribs 29 'which can be delivered, i.e. on the respective ribs of the thread pull-out lever 32. Are held by their ends on two holding ribs 48 which delimit ribs 29 'at their ends and are again integral with the thread pull-out lever 32 in the same manner as the ribs 29'. Open punched holes 49 are provided between the retaining ribs 48 and the respective associated ribs 29 '. These holes help to obtain a flexible elasticity of the retaining ribs 48 into which the steel pins 47 can be inserted. Similarly, the ribs 28 can be provided with hardened steel pins of this type along their tops as wear-resistant protection.

As seen in FIGS. 8 and 9 in conjunction with FIG. 3, the operation of pulling out the looper thread 14 and possibly also the gimp thread 15 is performed as follows.

The yarns 14 and 15 are in guide tubes 12 and 13 which are interrupted near the yarn pull-out device 27. The operation of inserting the looper thread 14 and possibly the gimp thread into the guide tube is performed with the cover 25 open. When the cover 25 is closed and the device 27 is opened, that is, with the thread pull-out lever 32 rotated backward, the looper thread 12 and the gimp thread 13 are present in front of the rib 28 as seen in FIG. And it is smooth and straight. Depending on the setting of the setscrew 40, the depth a of the rib 29 or 29 'will move by the width a between the ribs 28 when the device 27 is closed, determines how deep it moves. As the valve 40 is shortly triggered by the control system 41 to withdraw the thread, the thread withdrawal lever 32 pivots from its rest position to the working position. The dispensable ribs 29 and 29 'move between the ribs 28 while pulling out one or more yarns. FIG. 9 also shows the looper thread 14 and the gimp thread 15 winding in the device 27 without being clamped in the groove 30. When the thread puller 27 is opened by relieving the pressure of the drive 35, a portion of the looper thread, possibly multiplied by the width a, approximately corresponding to the total number of ribs 28 and 29 or 29 ', and possibly also a portion of the gimp thread, is available. . After opening the thread puller 27, the looper thread 14 and possibly the gimp thread 15 will also be frictionally retained in the grooves formed by the ribs 28 and the side plates 46. The yarn remains in its defined yarn position and can be used up.

The thread pull-out operation can be performed before sewing the seam 50 of the buttonhole 51 and / or during the process of sewing the threads 13, 14, 16 and cutting the thread with the thread cutter 11a.

It is a side view of an eye buttonhole sewing machine. FIG. 2 is a front view of the eye-shaped buttonhole sewing machine indicated by an arrow II in FIG. 1. FIG. 3 is a rear view of the pillar of the sewing machine along arrow III in FIG. 2. FIG. 4 is a vertical partial sectional view of the column taken along the arrow IV-IV in FIG. 3. FIG. 5 is a view of the rear cover of the column according to the arrow V in FIG. 4. FIG. 9 is a partial view of a rib of the thread pull-out lever indicated by an arrow VI in FIG. 8. 7 is a side view of the rib according to arrow VII in FIG. FIG. 5 is a schematic view when the yarn pulling device of FIG. 4 is opened. FIG. 3 is a view of the thread pulling device in a closed operating position. It is a figure showing a buttonhole.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Bottom plate 2 Top arm 3 Prop 5 Main drive motor 7 Needle bar 8 Needle 11 Hook 12 Looper thread guide tube 13 Gimp thread guide tube 14 Looper thread 15 Gimp thread 18 Work clamp 21 Work 25 Cover 27 Thread pull-out device 28 First Ribs 29, 29 'second rib 32 thread pull-out lever 35 linear drive device 42 set screw

Claims (11)

A buttonhole sewing machine for making a buttonhole seam in a processed product (21),
-A bottom plate (1), a top arm (2) and a column (3) connecting said bottom plate (1) and said arm (2);
A needle bar having a needle (8) and housed in an arm (2), which can be driven to reciprocate up and down by a main drive motor (5);
-A workpiece clamp (18) for clamping the workpiece (21);
A hook (11) arranged inside the bottom plate (1) and holding a looper thread (14);
-A guide for feeding the looper thread (14) along the path of travel to the hook (11);
-A loop puller (14), a thread puller (27) arranged in the feed path.
A buttonhole sewing machine comprising:
-Several first ribs (28) arranged along the feed path at a distance from each other;
A number of second ribs (29, 29 ') which are arranged at a distance from one another and which can be delivered towards said first ribs (28) and can be inserted between the first ribs (28); ), Whereby the looper thread (14) is drawn out in a meandering arrangement. The buttonhole sewing machine according to claim 1, wherein the looper thread (14) guide is a looper thread guide tube (12). The buttonhole sewing machine according to claim 1, characterized in that the gimp thread (15) guide is provided beside the side of the looper thread (14) guide. 4. The buttonhole sewing machine according to claim 3, wherein the gimp thread (15) guide is a gimp thread guide tube (13). The buttonhole sewing machine according to any one of claims 1 to 4, wherein the first rib (28) is formed on a wall of the column (3). ボ タ ン The buttonhole sewing machine according to claim 5, characterized in that the wall of the column (3) is a foldable cover (25). 7. The device as claimed in claim 1, wherein the second rib (29, 29 ') which can be delivered is formed on a thread pull-out lever (32) rotatably housed in the column (3). A buttonhole sewing machine according to any one of the preceding claims. The buttonhole sewing machine according to claim 7, characterized in that the thread pulling lever (32) can be rotatably driven by the linear driving device (35). 9. The arrangement according to claim 1, wherein the insertion depth of the second ribs (29, 29 ') which can be delivered between the first ribs (28) is adjustable. Buttonhole sewing machine. 10. The buttonhole sewing machine according to claim 9, wherein a set screw (42) is provided between the column (3) and the thread pull-out lever (32). The buttonhole sewing machine according to any one of claims 1 to 10, wherein the rib (29 ') is provided with a wear protection body.

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