CZ20003959A3 - Method and device for controlling a sewing machine feed roller - Google Patents

Description

Method and apparatus for controlling a feed roller for a sewing machine

Technical field

BACKGROUND OF THE INVENTION The invention relates to a method and apparatus for operating and controlling a feed roller for a sewing machine, the apparatus comprising a feed roller arranged in the fabric feeding direction upstream of the position where the stitch is to be formed. .

BACKGROUND OF THE INVENTION

Sewing machines are known, provided with fabric feeding means for moving the sewn object in cooperation with the shoe by sliding the feeder in a position where the stitch is to be formed, and further provided with a feed roller arranged to engage the sewn object from top to front in the fabric feeding direction. and is driven by a motor.

The feed roller serves to move the sutured article forward in the fabric feeding direction, pulling the sutured article in a greater amount of fabric feeding than the fabric feeding means.

However, this known feed roller can be rotatably driven in only one direction to advance the workpiece

forward in the fabric feeding direction. Thus, when a so-called reverse stitch having a reverse feed direction of the feeder during sewing is to be performed, the feeder and the feed roller pull out the sewn object from each other. As a result, the feed roller creates scratches on the upper surface of the sutured article, or a predetermined return feed amount cannot be achieved so that uniform stitches cannot be achieved. This deteriorates the quality of the sewn object.

For this purpose, constructions are also known in which the feed roller is raised and held so that it does not engage the sewn object when it is fed back through the feeder. It is necessary to use driving means for such lifting of the feed roller, such as a solenoid, or some time is required to feed the solenoid to raise the feed roller. As a result, the speed of the sewing machine is reduced, so that the sewing efficiency is also reduced.

In addition, the feed back of the feeder starts before the feed roller is lifted and separated from the sutured article, which leads to a deterioration in the quality of the sutured article.

Furthermore, a construction is also known in which the feed roller rotates in the opposite direction when it is fed back through the fabric feeder.

However, in the known construction, in which the feed roller rotates in the opposite direction when the fabric feeder moves back as mentioned above, however, the feed is performed in the same amount of feed as the feed, i.e. the feed is performed in a larger the amount administered than the amount administered by the fabric delivery means.

As a result, the sewn object which is fed backwards is released between the shoe and the feed roller, whereby it is finally wrinkled, so that it is fed and sewn under the shoe. As a result, there is a problem that the value of the goods of the sewn product is reduced, while its quality is also deteriorated.

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to provide a sewing machine which overcomes the drawbacks of the prior art.

In order to accomplish the above object, in accordance with the present invention, a method of operating a feed roller for a sewing machine has been developed in accordance with which when the fabric feeding means for moving the sewn object and for optionally reversing the forward and reverse direction of fabric feeding in a position the stitch being brought into a re-feed condition, the control is performed such that the back-feed amount of the feed roller for moving the sutured article by rotating in a lower engagement with the stitched object in front of the fabric feeding means in the fabric feeding direction is equal to or less the amount of fabric delivery means administered.

In accordance with another aspect of the present invention, there is also provided a method of operating a feed roller for a sewing machine according to which, when the fabric feeding means for moving the sewn object and for optionally reversing the forward and reverse feed direction of the fabric in the stitching position When the backfeeding condition is set back, the control is performed such that the backfeeding amount of the feed roller to move the sutured article by rotating in a lower engagement with the stitched object in front of the fabric feeding means in the fabric feeding direction is less than the backfeeding amount of the feed roller.

In accordance with yet another aspect of the present invention, there is also provided an apparatus for operating a feed roller for a sewing machine, comprising:

fabric supply means for moving the sewn article for selectively reversing the forward and reverse direction of fabric feed in the position where the stitch is to be formed, a feed roller for moving the stitched article by rotating in bottom engagement with the stitched article in front of the fabric supply means in the fabric direction drive means for rotating the feed roller for selectively reversing the forward and reverse directions of fabric feed, and control means for performing control such that the direction of rotation of the drive means is reversed depending on the feed direction of the fabric feed means, the control means shifting the feed roller back re-administered amount than is forward administered

the amount of feed roller when the fabric feeding means is brought back into the feed state.

In accordance with yet another aspect of the present invention, there is also provided an apparatus for operating a feed roller for a sewing machine, comprising:

fabric supply means for moving the sewn article for selectively reversing the forward and reverse direction of fabric feed in the position where the stitch is to be formed, a feed roller for moving the stitched article by rotating in bottom engagement with the stitched article in front of the fabric supply means in the fabric direction drive means for rotating the feed roller for selectively reversing the forward and reverse direction of fabric feed, and control means for effecting control such that the direction of rotation of the driving means is reversed depending on the feed direction of the fabric feed means, to the reverse direction and change the return amount to be equal to or less than the return amount of the fabric delivery means, when the fabric delivery means is brought back into the feed state.

In accordance with yet another aspect of the present invention, there is also provided an apparatus for operating a feed roller for a sewing machine, comprising:

fabric feeding means for selectively reversing the fabric feeding direction to the forward and reverse fabric feeding direction in the stitching position, a feed roller for moving the sutured article by rotating in a lower engagement with the sutured article in front of the fabric feeding means in the fabric feeding direction, drive means for rotating or stopping the feed roller, and control means for controlling the rotation of the driving means as a function of the feed direction of the fabric feeding means, said control means stopping the driving means for bringing the feed roller into operation when the fabric feeding means is brought into back-feed condition.

When the fabric feeding means is brought back to the sewing machine condition, the feed roller is brought into the feed amount, the rotation of the feed roll for the feeder is less than the feed amount with the conventional roller, or the running condition.

As a result, a backfeeding operation is performed without releasing the seamed article in front of the foot.

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BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail by way of examples of specific embodiments thereof, the description of which will be given with reference to the accompanying drawings, in which:

Fig. 1 is a side elevational view showing a sewing machine to which a feed roller is attached in accordance with an embodiment of the present invention;

Fig. 2 shows a control circuit of a sewing machine according to a first embodiment of the present invention;

FIG. 3 is a flow chart for controlling feed back in accordance with a first embodiment of the present invention;

FIG. 4 is a flow diagram illustrating a subroutine for controlling the reverse rotation of a pulse motor in accordance with a first embodiment of the present invention;

Fig. 5 shows a control circuit of a sewing machine according to a second embodiment of the present invention;

FIG. 6 is a flowchart for controlling feed back in accordance with a second embodiment of the present invention;

Fig. 7 shows a control circuit of a sewing machine according to a third embodiment of the present invention;

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FIG. 8 is a flowchart for controlling feed back in accordance with a third embodiment of the present invention;

FIG. 9 is a flow chart illustrating a subroutine for controlling the reverse rotation of a pulse motor in accordance with a fourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

It can be seen from FIG. 1 that the needle N, mounted on the head portion N of the sewing machine, is movable vertically, is connected to the drive motor of the sewing machine (not shown). In addition, the shoe 1, which is mounted on the head part M of the sewing machine movably vertically and which serves to absorb the elastic forces, is brought into contact with the sewn object W on the needle plate P by the elastic force pressure in the lower position.

The feeder 2, arranged below the needle plate P, performs an elliptical movement (movement in four feed directions by means of a generally known mechanism causing a feeder movement (not shown), which is connected to the sewing machine drive motor. a mechanism, such as a feed quantity change mechanism, for varying the feed angle control cam acting on the feed movement generating mechanism, thereby changing the feed amount of the feeder 2 or the feed back mechanism to act on the feed mechanism change the feed rate via the return lever control 9 9 9 9 9 9 9 9 9

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Feeding to change the feed direction of the feeder 2 from the forward direction (see arrow X in FIG. 1) to the feed direction.

The support shaft 4, bearing at its lower end the feed mechanism A, is mounted movably vertically at the end of the support arm 3 extending from the head portion M of the sewing machine back in the fabric feeding direction (to the left in FIG. 1). The support shaft 4 always transmits the actuating force downwards by a compression spring 5 wound on the support shaft 4.

The feed mechanism A consists of a support member 6 attached to the lower end of the support shaft 4, a support arm 7 extending downwardly from the support member 6 on this side in the fabric feeding direction (right in FIG. 1), of a pulse motor 8; attached to the support member 6, from a feed roller 9 which is rotatably driven by a pulse motor (3) and from a toothed transmission belt 10 for interconnecting the feed roller 9 and the pulse motor 85. The construction of this supply mechanism A is well known.

The first embodiment of the present invention will now be described.

It can be seen from FIG. 2 that the angle of rotation sensor 11 senses the extent of the angle of rotation during one revolution of the main spindle of the sewing machine, corresponding to the period of time that the feeder 2 protrudes upward from the fabric feed plate P and generates a feed time signal. for each angle of rotation range.

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The feed quantity adjusting means 12a and 12b adjust the feed forward and return feed rates of the feed roller 9 ^and generate feed amount data corresponding to the value set by the operator. The lower feed detecting means 13, arranged depending on the feed quantity change mechanism or the feed movement mechanism, detect the feed amount of the feeder 2 and generate a lower feed signal corresponding to the feed amount.

The feed direction detecting means 14, depending on the feed motion generating mechanism or the feed back mechanism, detects whether the feed direction of the feeder 2 is forward or backward and generates a status signal corresponding to each condition.

A control program for each sewing machine device is stored in the ROM ROM 15. In the RAM direct access memory 16, the set values for the amount adjustment means 12a and 12b or the status signal for the feed direction detection means 14 are stored. The CPU 17 controls and controls each sewing machine assembly in accordance with a control program.

The sewing machine drive motor 18 drives and stops the sewing machine. The drive mechanism 19 of the drive motor 18 drives and stops the drive motor 18 of the sewing machine. The drive mechanism 20 of the pulse motor 8 for driving or stopping the pulse motor 81 in the forward or reverse direction rotates the pulse motor 85 in synchronization with the generation of a feed time signal that controls the CPU CPU 17. The pedal sensor 21 is arranged relative to the pedal ( not shown) for generating an engagement signal when the pedal is pressed forward and for generating a stop signal when the pedal is released.

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Referring now to the flowchart of FIG. 3, the operation and control of the pulse motor 8 will now be described.

The forward and backward feed rate adjustments of the feed roller 9 are passed from the feed rate adjusting means 12a and 12b to the ROM 15 (in step S-1). If the pedal sensor 21 detects a forward depression of the pedal (in step S-2), the sewing machine drive motor 18 is actuated by the drive mechanism 19 of the drive motor 18 (in step S-3).

Typically, the feeder 2 is placed in a feed forward state during start-up (see step S-4), wherein the feed forward status signal is generated by the feed direction detection means 14. Each time the feed time signal is generated, the forward feed amount is adjusted by the feed rate adjusting means 12a for the pulse motor 8 via the drive device 20 of the pulse motor 13 so that the pulse motor 8 is thus driven (see step S-5). Typically, the feed amount of the pulse motor is set to be greater than the feed amount of feeder 2 during forward feed.

If a pedal release is detected by the pedal sensor 21 (in Step S-6), the sewing machine drive motor 18 is stopped (in Step S-7) and the pulse motor E3 is also stopped (in Step S-6).

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If the feeder 2 is brought back into the feed condition by operating the reverse stitch lever during feed forward so that a feed status signal is generated by the feed direction detecting means 14 (in Step S-4), a subroutine for controlling the pulse motor reverse rotation is performed. C3 (in Step S-9).

With respect to this subroutine for controlling the reverse rotation of the pulse motor 38 (see FIG. 4), the feed rate is primarily set by the feed rate setting means 12b. If the fabric feed timing signal 11 is generated by the rotation angle sensor 11 (at step S-92), then the pulse motor drive mechanism 20 drives the pulse motor 13 in the opposite direction of rotation to reach the set value (step S-93).

The operator always sets the backfeed amount of the pulse motor 18 to be less than the forward fed amount of the pulse motor 18, for example to be equal to or less than the backfeed amount of the feeder feeder.

Next, a second embodiment of the present invention will now be described with reference to the Figures 5 and 6.

The control circuit shown in FIG. 5 has the same structure as the control circuit of the first embodiment of the present invention (see FIG. 2), except that there are no feed rate setting means 12a and detection means 13 therein. lower feed.

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As shown in FIG. 6, when the pedal is pressed forward (step S-21), the sewing machine drive motor 18 is driven (step S-2). In the state of the feed feeder 2, the pulse motor then rotates the feed roller so as to have a feed rate set by the feed rate setting means 12a.

In steps S-25 to S-27, the same control operation is performed as in the first embodiment of the present invention.

If a feed back condition (step S-23) is detected, the drive device 20 of the pulse motor 8 will stop the pulse motor 8 (S-29).

As a result, the feed roller 9 is brought into an overrun condition for loss of the actuating force for moving the sewn object W. Thus, the sewn object W is displaced only by the back feed operation of the feeder 2.

Next, a third embodiment of the present invention will be described with reference to the Figures 7 and 8.

The structure shown in FIG. 7 is the same as that of the first embodiment of the present invention (see FIG. 2) except that there are provided re-feed command means 22, solenoid driver 23 and solenoid 24. for back-feed, while the feed direction detection means 14 are not provided here.

The recoil command means 22 has a well-known switch structure arranged in the arm

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the sewing machine frame member. If the operator presses this switch, a feed back instruction is given.

The feed back solenoid 24 is well known and serves to act on the mechanism to change the feed rate during its feeding and to position the feeder 2 in the feed direction.

As shown in Figure 8, the same control operations as in the first embodiment of the present invention (see Figure 3) are performed in steps S-31 to S-33 and steps S-35 to S-38.

If the feed back command means 22 is controlled to give a feed back command (step S-34), the feed back solenoid 24 is energized via the solenoid drive driver circuit 23 so that the feeder 2 is brought back to feed. The amount of backfeed is preset at the base of the mechanism.

Then, a subroutine (step S-40) is executed to control the reverse rotation of the pulse motor Ej. By means of the same control operations (see FIG. 4) as in the first embodiment of the present invention, the pulse motor 13 is controlled to rotate in the opposite direction, the feed roller 9 being moved back by an amount of feed back that is nearly equal to or smaller than feeder 2.

Next, a fourth embodiment of the present invention will be described.

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The circuit structure of the fourth embodiment of the present invention is the same as that shown in Figure 5. In other words, the amount adjustment means 12b and the lower dose detection means 13 according to the first and second embodiments of the invention not required.

The subroutine (see FIG. 4) for reversing the pulse motor 8 shown in the figures of FIG. 3 and FIG. 8 is changed to the subroutine shown in FIG. 9.

More specifically, the back feed amount of feed roller 9 is calculated to be N% of the forward feed amount (which is 100% of the forward feed amount, i.e., equal to the forward feed amount of this embodiment) (step S-94).

The feed back amount is set to the value obtained as a result of the calculation (steps S-95). If a feed timing signal (step S-96) is given, the drive device 20 of the pulse motor 8 drives the pulse motor 8 in the opposite direction.

The operator can change and set the set value of N% in the calculation to be 100% or less. As a result, the feed roller can be moved back through a finer adjustment. In addition, the calculation may be performed in proportion to the backfeed amount of the feeder 21.

If the backfeed amount of the feed roller is equal to or less than the backfeed amount of the feeder 2 in each embodiment, it is preferred that the backfeed amount

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the feed roller 9 was less than its feed rate.

Although the pulse motor 8 is controlled to rotate the feed roller 9 only at the feed time during one revolution of the sewing machine main spindle in each embodiment, the feed roller 9 can be rotatably driven during full time during one revolution of the sewing machine main spindle to increase sewing machine speed. In this case, it is not necessary to use rotation angle sensors 11 for steering.

Industrial applicability

In accordance with the present invention, the amount of fabric fed for the re-feed operation of the feed roller is set to be less than or equal to or less than or equal to the back-feed amount of the feeder.

Therefore, the sewn object being fed back does not loosen between the shoe and the feed roller while preventing it from wrinkling when it is fed and sewn under the shoe.

As a result, it is possible to overcome common deficiencies which reduce the value of the goods in the sewn product as well as deteriorate its quality.

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PATENT CLAIMS

Claims (5)

PATENT CLAIMS A method of operating a feed roller for a sewing machine, characterized in that when the fabric feeding means for moving the sewn object and for optionally reversing the forward and reverse feed direction of the fabric in the position where the stitch is to be formed, the control is performed such that the backfeed amount of the feed roller for moving the sutured article by rotating in a lower engagement with the stitched object in front of the fabric feed means in the fabric feed direction is equal to or less than the backfeed amount of fabric feed means. A method of operating a feed roller for a sewing machine, characterized in that when the fabric feeding means for moving the sewn object and for optionally reversing the forward and reverse feed direction of the fabric in the position where the stitch is to be formed, the control is performed so that the backfeed amount of the feed roller for moving the sewn object by rotating in a lower engagement with the sewn object in front of the fabric feeding means in the fabric feed direction is less than the backfeed amount of the feed roller. 3. A device for operating a feed roller for a sewing machine, comprising: 0Φ • <0 0 · 0 • 00 · 0 • • 00 00 0 0 0 0 0 0 0 0 0 0 0 0 ·· • 0 000 00 0 0 ·· fabric supply means for moving the sewn article for selectively reversing the forward and reverse direction of fabric feed in the position to be stitched, a feed roller for moving the stitched article by rotating in bottom engagement with the stitched article in front of the fabric supply means in the fabric feed direction; drive means for rotating the feed roller for selectively reversing the forward and reverse direction of fabric feed, and control means for effecting control, such that the direction of rotation of the drive means is reversed depending on the feed direction of the fabric feed means, a back feed roller in a small back feed amount than the feed roll amount of the feed roll when the fabric feeding means is brought back administration. 4. Apparatus for operating a feed roller for a sewing machine, comprising: fabric feeding means for moving the sewn object for selectively reversing the forward and reverse directions of feeding the fabric in the position where the stitch is to be formed, a feed roller for moving the sewn object by rotating in the bottom engagement with the sewn object In front of the fabric feeding means in the fabric feeding direction, the driving means for rotating the feed roller for selectively reversing the forward and reverse fabric feeding directions, and the control means for performing the control so that the direction the rotation of the driving means is reversed depending on the feeding direction of the fabric feeding means, wherein the control means adjusts the feeding direction of the feed roller fabric to the reverse direction and changes the return feeding amount to be equal to or less Than the reverse feed quantity means for feeding the fabric, when the means for feeding the fabric brought into a state for reverse feed. 5. A device for operating a feed roller for a sewing machine, comprising: fabric feed means for selectively reversing the fabric feed direction to the feed forward and reverse direction of the fabric feed position in the stitching position, the feed roller for moving the stitched article by rotating in a lower engagement with the stitched article drive means for rotating or feeding roller, and stop means for controlling the rotation of the driving means in dependence on the feeding direction of the cloth feeding means, characterized in that said control means stops the driving means for bringing the feeding roller into a running state when the fabric feeding means is brought back into the feed state.