JPS62120884A - Cloth presser raising and falling apparatus of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) This invention relates to a presser foot lifting device for a sewing machine.

(Prior art) This type of conventional presser foot lifting device is [! When rotating the work cloth during operation, or! 2! There is a known structure in which the presser foot is moved from a lower working position where it presses against the workpiece cloth to an upper non-working position when the workpiece cloth is attached or removed at the end of manufacturing.

(Problem to be Solved by the Invention) However, in this conventional device, the amount of upward movement of the presser foot is predetermined as the distance from the top surface of the throat plate, regardless of the thickness of the workpiece cloth. When a thick work cloth is made of N, a sufficient gap is not formed between the upper surface of the work cloth and the lower surface of the presser foot, making it impossible to smoothly rotate or attach/detach the work cloth; When sewing thin work cloths, there is a problem in that too large a gap is created between the upper surface of the work cloth and the lower surface of the presser foot, making it impossible to accurately rotate and position the work cloth during attachment.

The present invention has been made in view of the above-mentioned problems, and includes a presser foot supported on a sewing machine frame so as to be movable up and down, and a drive means for raising and lowering the presser foot.
In a sewing machine that performs sewing operation with the presser foot being lowered via the driving means from an upper inactive position to an active position where it presses against the workpiece cloth, the height of the presser foot at the active position is lowered. a detection means for detecting the height of the presser foot; a setting means for setting the amount of rise of the presser foot from the working position by the operation of the driving means; By operating the driving means based on the working position information from the detecting means and the rising date information from the setting means, the control means raises the presser foot from the working position by the amount of rise ω set by the setting means. -I'm getting it.

(Function) Therefore, when lifting and lowering the presser foot of the sewing machine of this invention,
When rotating the workpiece cloth during the sewing operation or when removing and attaching the workpiece cloth at the end of the sewing operation, the presser foot is raised by the 1-minute rise set by the setting means in accordance with the thickness of the workpiece cloth. A predetermined gap is always formed between the upper surface of the work cloth and the lower surface of the presser foot, allowing for smooth rotation and attachment/detachment of the work cloth, as well as positioning when rotating and attaching the work cloth. can be done accurately.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

In the sewing machine of this embodiment, as shown in FIG. 1, a presser foot 2 is supported on the head of a sewing machine frame 1 so as to be movable up and down, and a presser foot holder 3 is attached to the upper end of the presser foot 2.
A presser foot 4 as a cloth presser is attached to the lower end. A presser spring 2a is disposed on the presser bar 2, and applies presser pressure to the work cloth via the presser foot 4 based on the spring force adjusted by an adjusting screw 2b. A first rotary lever 5 is rotatably supported within the sewing machine frame 1 in the vicinity of the presser bar holder 3, and the presser bar holder 3 is rotated by the action of a spring 6.
is biased to rotate in the direction of engagement. A second rotary lever 7 is provided within the sewing machine frame 1 corresponding to the first rotary lever 5.
is rotatably supported, and a connecting rod 8 is interposed between one arm portion and the first rotating lever 5, and an operating rod 9 is connected to the other arm portion.

As shown in FIG. 1.2, an oil pan 10 provided at the bottom of the sewing machine frame 1 has a substantially rod-shaped linking body 11.
It is supported so as to be able to move linearly between three upper and lower positions corresponding to the raised and lowered positions of the presser bar 2, and the operating rod 9 is engaged at the lower end of the upper part of the presser bar 2. The first rotating lever 5, the connecting rod 8, the rotating lever 7 of the WS2, the operating rod 9, and this linking body 11 constitute an operating mechanism 12, and the linking body 11 of the operating mechanism 12 is directed upward. When the presser foot 2 and the presser foot 4 are moved to the position shown in FIG.

As shown in FIG. 1, a needle bar 13 is supported on the head of the sewing machine frame 1 in front of the presser foot 2 so as to be movable up and down.
A needle 14 is attached to its lower end. When the sewing machine main shaft (not shown) is rotated based on the activation of the motor 15 shown in FIG. Stitches are formed on the work cloth on the bed by cooperation with a thread loop catcher (not shown) provided in the machine.

As shown in FIGS. 1 to 4, a support bracket 16 is provided on the lower surface of the oil pan 10 near the lower end of the linking body 11.
is attached with screws 17. Support bracket 1
6 has a servo solenoid 18 constituting the drive means.
is JIl? by a plurality of screws 19? s, and an armature 20 is protruded from the center of the upper surface thereof so that it can penetrate through the support bracket 16 and be retractable. In this embodiment, the linking body 11 is attached to the upper end surface of the armature 20.
The lower ends of the linking body 11 and the armature 20 are directly engaged with each other.

Further, a horizontal forked arm 21 is provided at the rear of the armature p20.
is provided protrudingly, and a vertical three-pronged arm 22 is provided protrusively from the front portion. A guide pin 23 is provided protruding from the upper surface of the support bracket 16 at the rear of the armature 20 and engages with the horizontal fork arm 21 to guide the movement of the armature 20 into and out. When the armature 20 of the servo solenoid 18 is moved to protrude from the upper direction U shown by the solid line in FIG. The presser bar 2 and presser foot 4 are raised via the presser bar holder 3.

In front of the armature 20, a potentiometer 24 as a momentum detector is mounted on the upper surface of the support bracket 16 above the servo solenoid 18 via a mounting plate 25, and an operating shaft 26 protrudes from the right side thereof. A rotary lever 27 is fitted and fixed on the operating shaft 26 on the base ψ, and a pin 27a that engages with the vertical bifurcated arm 22 of the armature 20 is protruded from the left side surface of the tip thereof. Then, when the armature 20 of the servo solenoid 18 is operated to project and the presser bar 2 and the presser foot 4 are raised,
As the armature 20 projects, the operating shaft 26 of the potentiometer 24 is rotated via the vertical forked arm 22 and the rotation lever 27, and the potentiometer 24 outputs a detection signal corresponding to the amount of movement of the armature 20. It has become.

As shown in FIG. 1, below the sewing machine frame 1 is a foot-operated operation pedal 2 for operating a switch means.
8 is placed. When the rear part 28a side of the operating pedal 28 is depressed, an activation signal is outputted to drive the motor 15 to rotate at a speed corresponding to the amount of depression. Further, a needle position detector 65 (see FIG. 6), which constitutes a counting stop signal generating means and a needle down stop signal generating means, is attached to the end of the main shaft of the sewing machine (not shown), and the needle position detector 65 (see FIG. 6) is attached to the end of the main shaft of the sewing machine (not shown). When the needle is returned to the position, the needle position detector 65 outputs a needle down stop signal to stop the rotation of the motor 15 and stop the needle 14 at the bottom dead center below the throat plate. When the front part 28b side of the pedal 28 is pressed down, the motor 1
After thread trimming is performed by slightly rotating the needle 5, a count stop signal is output to stop the needle 14 at the top dead center above the needle plate block.

As shown in FIG. 1, a potentiometer 32 for detecting the height of the presser foot, which constitutes a detection means, is disposed in the head of the sewing machine frame 1 in correspondence with the presser foot holder 3. Actuation axis 3
A vinyl ring 35 is provided at the tip of the presser foot 4 and engages with a rack 34 on the presser bar holder 3.
The actuating shaft 33 of the potentiometer 32 is rotated via the rack 34 and the pinion 35 as the needle moves up and down, and the needle position is detected by operating the operating pedal 28! When the operation of the sewing machine is stopped at the throat plate based on the needle lowering stop signal from Pj65 as shown in FIG. The height l-11 from the top surface is detected and a corresponding detection signal is output, and based on the counting stop signal from the needle position detector 65, the operation of the sewing machine is counted as shown in FIG. 5(b). When stopped at , the potentiometer 32
detects the height 12 from the upper surface of the throat plate at the operating position of the presser foot 4 in its stopped state, and outputs a detection signal corresponding thereto.

As shown in FIG. 1, an operation box 29 is provided at the bottom of the sewing machine frame 1. The operation box 29
is provided with a rising movement port setting device 30 such as a variable resistor constituting a setting means, and when positioning the work cloth when sewing resumes or rotating the work cloth during I-making, the presser foot is activated by the operation of the servo solenoid 18. Leg 4 is shown in Figure 5 (a
) In (b), it is possible to set in advance the amount of upward movement from the lower working position where it is in pressure contact with the work cloth, shown by the solid line, to the upper non-working position shown by the chain line. Further, the operation box 29 is provided with a time switch 31 constituting a timer means, and 8! Upon completion of manufacturing operation,
After the presser foot 4 is moved to the highest position based on the operation of the servo solenoid 18, the time required for the presser foot 4 to be moved to the upper limit position set by the raised position setting device 30 can be arbitrarily set. There is.

Next, in the sewing machine configured as described above, the configuration of the control circuit mainly for controlling the operation of the servo solenoid 18 will be explained with reference to FIG.
The read-only memory (ROM) 52 is in the PU) 51.
and random access memory (RAM) 53 are connected. The ROM 52 stores programs for controlling the entire sewing machine, and the RAM 53 stores the operating amount of the potentiometer 24 corresponding to the operation of the armature T-20 of the servo solenoid 18, and the presser foot corresponding to the operating amount of the potentiometer 32. Movement amount of leg 4, rising position setting device 30
The operation of the servo solenoid 18 according to the set value of is stored.

Further, a potentiometer 24 for exercise detection, a potentiometer 32 for detecting presser foot height, a lift setting device 30, a time switch 31, and an operation pedal 28 are connected to the CPLI 51 via an input interface 54,
Various signals from them are input to the CPU 51. Further, the servo solenoid 18 and the motor 15 are connected to the CPU 51 via an output interface 55 and drivers 56 and 57, so that a drive or stop signal is output from the CPU 51 to the servo solenoid 18 and the motor 15.

Next, the operation of the sewing machine configured as described above will be explained.

Now, when using this sewing machine to sew pieces of cloth such as patches on the front surface of processed cloth, for example,
When the power of the sewing machine is turned on, the program shown in the flow diagram of FIG. When the pedal is depressed and a drive signal is input to the CPU 51, the program proceeds to step S2. In step S2, the presser bar 2 is lowered based on the OFF of the servo solenoid 18, and a predetermined presser pressure is applied to the work cloth by the presser foot 4 in the operating position. The sewing machine is activated at a rotational speed corresponding to the depression j, and the sewing operation of the sewing machine is started.

In the next step S4, even after waiting for a pull-down stop signal from the oblique δ detector 65, when the operating pedal 28 is returned from the depressed state to the neutral state and the 21-down stop signal is input to the CPU 51. , the rotation of the motor 15 is stopped and the needle 14 is stopped at the bottom dead center, and at the same time the step $
5, the height 1''1 (FIG. 5(a)) of the presser foot 4 at its operating position in its stopped state is determined by the potentiometer 3.
2, and the detection signal is input to the CPU 51. In the next step S6, it is determined whether the thread is to be trimmed or not, and when an accrual stop signal is input to the CPU 51 based on the depression of the front part 28b side of the operating pedal 28, the motor 15 is slightly rotated to trim the thread. After the injection is performed, the needle 14 is stopped at the top dead center. In the next step, S7, when the needle 14 is stopped at the top dead center with the needle up, the process proceeds to step S8, where the presser foot 4 is stopped in the stopped state.
The height H2 (FIG. 5(b)) at the operating position is detected by the potentiometer 32, and the detection signal is CP
It is input to tJ51. In the next step S9, the servo solenoid 18 is turned on, the presser foot 4 is raised to the highest position, and the pressure on the work cloth is released. Therefore, the work cloth can be easily taken out with the presser foot 4 placed at the highest position.

In the next step S10, after the presser foot 4 is raised to the highest position, it is determined whether or not a predetermined time set by the time switch 31 has elapsed, and an output is output at the same time as the elapse of the set time. In response to the presser foot lifting signal, in step 311, the servo solenoid 18 is activated based on the detected height information H2 of the potentiometer 32 and the set amount information of the upward movement fixing setter 30, and the presser foot 4 is raised.
is moved from the lower working position shown by the solid line in FIG. 5(b) to the upper non-working position shown by the chain line. Therefore, in this state, a gap of a predetermined distance is formed between the upper surface of the work cloth and the lower surface of the presser foot 4, allowing easy and accurate positioning of the work cloth for the next sewing. can do. Then, in the next step 812, it is determined whether or not the operating pedal 28 has been depressed, and if the operating pedal 28 is depressed and the sewing operation is restarted, the process returns from step S12 to step S2, The presser foot 4 is lowered to the operating position based on the operation of the servo solenoid 18, and if the operating pedal 28 is not depressed in step S12, IK1 is recognized and the operation of the sewing machine is terminated.

On the other hand, in the determination in step S6, if the workpiece cloth and the piece of cloth such as a patch are to be rotated without cutting the thread after the needle has stopped lowering, and another edge of the cloth piece is to be sewn, then step S6 The process advances to step S13. In this step S13, in response to the presser foot lifting signal, the servo solenoid 18 outputs the detected height information of the potentiometer 32! 1 and the set amount information of the upward movement amount setter 30, the presser foot 4 is moved from the lower working position shown by the solid line in FIG. 5(a) to the upper non-working position shown by the chain line. After that, the process returns to step S1 and waits for the operation pedal 28 to be depressed. Therefore, even in this state, a gap of a predetermined distance is formed between the upper surface of the work cloth and the lower surface of the presser foot 4, making it possible to easily and accurately rotate and position the work cloth.

Next, another embodiment of the present invention will be described with reference to FIG. 8. In this embodiment, a pair of front and rear support legs 60 are protruded from the lower surface of the oil pan 10 near the left side of the armature 20 on the servo solenoid 18. and both supporting legs 60
A rotation shaft 61 is supported rotatably around a horizontal axis. An actuating member 62 is fitted and fixed to the front end of the rotation shaft 61, and an actuating protrusion 62a is formed projecting from the negative side thereof. An operating lever 63 is protruded from the lower part of the operating member 62, and the operating member 6 is operated by operating the operating lever 63 with the knee.
2 can be rotated to the right.

An operating switch 64 is provided at the lower part of the sewing machine frame 1 in correspondence with the operating protrusion 62a of the operating member 62.

Then, positioning the work cloth and sewing when sewing resumes.
When the operating member 62 is rotated to the right based on the operation of the operating lever 63 during the rotation operation of the work cloth during i, the operating switch 64 is closed and the servo solenoid 18 is actuated from the switch 64. A presser foot lifting signal is output for this purpose.

Also, in this embodiment, instead of the counting stop signal and needle plate stop signal from the needle position detector 65 based on the operation of the operating pedal 28 in the previously described embodiment, the presser foot lifting signal from the operating switch 64 is used. The servo solenoid 18 is actuated to move the presser foot 4 from a lower working position shown by a solid line in FIGS. 5(a) and 5(b) to an upper non-working position shown by a chain line. Therefore, in this embodiment, the presser foot 4 can be moved from the working position to the non-working position at desired timing based on the operation of the operating levers 6 and 3.

Note that the present invention is not limited to the configurations of the above-described embodiments; for example, in a sewing machine that selects the a-made pattern and performs sewing according to a predetermined sewing pattern,
Without departing from the spirit of the present invention, for example, the lifting movement setting device 30 and the time switch 31 may be configured to be automatically set to a setting value suitable for the selected sewing pattern in accordance with the selection of the sewing pattern. It is also possible to make specific changes by arbitrarily changing the configuration of each part.

Effects of the Invention As described in detail above, the present invention has the advantage that when the workpiece cloth is rotated during the sewing operation or when the workpiece cloth is attached/detached at the end of the sewing operation, the presser foot is adjusted to correspond to the thickness of the workpiece cloth. It is raised by the amount of rise set by the setting means, and the
A predetermined gap is always formed between the upper surface of the cloth and the lower surface of the presser foot, allowing smooth rotation of the work cloth and IIRI operation, as well as accurate positioning when rotating and attaching the work cloth. Qin has an excellent effect that can be done.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view showing an embodiment of a sewing machine embodying the present invention, FIG. 2 is a partial sectional view showing an enlarged support configuration of a servo solenoid, and FIG. 3 is a line A-A in FIG. A partial cross-sectional view along the line, Figure 4 is along the line B-B in Figure 2.
Fig. 5 (I) (b) is a partial sectional view for explaining the movement of the presser foot between the working position and the non-working position in the needle down stop state and the counting stop state.
The figure is a control circuit diagram for controlling the operation of the servo solenoid and motor, FIG. 7 is a flowchart showing the operation of the sewing machine manufactured by N, and FIG. 8 is a partial perspective view of the sewing machine showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Sewing machine frame, 2... Presser bar, 4... Presser foot as a cloth presser, 18... Servo solenoid constituting drive means, 28... Operating pedal, 30... Setting An upward moving suspension setting device as a means, 32... Potentiometer as a detection means, 51... CPU. Patent applicant Agent: Brother Industries, Ltd.
Patent Attorney On 1) Hironobu Figure 5 (a) (b)

Claims (1)

[Claims] 1. A presser foot (1) supported on the sewing machine frame (1) so as to be able to rise and fall;
4) and a drive means (18) for raising and lowering the presser foot (4), and the drive means (18) is provided with a
8), in which the sewing machine performs sewing operation with the presser foot (4) lowered from an upper inactive position to an active position where it presses against the workpiece cloth, the working position of the presser foot (4) height (H1, H2
), a setting means (30) for setting the amount of rise (h) of the presser foot (4) from the working position due to the operation of the driving means (18); In response to a presser foot lifting signal generated at the end of sewing, the drive means (18) is activated by the detection means (3).
The presser foot (4) is operated based on the operating position information from the presser foot (2) and the lifting amount information from the setting means (30).
) and a control means (51) for raising the presser foot by an amount set by the setting means (30) from the operating position.