JPS62152498A - Pressing, lifting 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] (Industrial Application Field) The present invention relates to a presser foot lifting device for a sewing machine, and is particularly used for a presser foot lifting device in a cycle sewing machine such as a bar tacking sewing machine. .

(Prior Art) Conventionally, as this type of device, the technology shown in the specification and drawings of Japanese Patent Publication No. 52-29212 is known. That is, a power assist mechanism is used to drive the presser foot lifting operation cam using the power of the sewing machine drive motor, thereby raising the presser foot against the pressure of the presser foot with a light operating force, thereby improving the work. The aim is to improve operability for users.

(Problems to be Solved by the Invention) In the above-mentioned prior art, the presser foot was operated via a constantly rotating drive member. In general, for configuration work,
Even when the sewing machine is stopped, the presser foot needs to be readily operable when checking the state of the fabric being held.

Therefore, in the above technique, the sewing machine motor, which is the drive source for the presser foot drive member, is kept rotating at all times, and the driving of the main shaft of the sewing machine body and the presser foot are completely separated by clutches. These configurations have become complex and large, and various inconveniences have arisen as a result.

In addition, in recent years, the use of DC motors has become widespread in order to save energy, and a method has been adopted in which the motor is stopped when sewing is not being performed, and the motor is rotated at the same time as the sewing machine is started. In such a case, it is impossible to achieve the purpose with the above-mentioned conventional device.

In the present invention, the presser foot can be easily moved up and down independently of the sewing machine drive motor, thereby solving the inconveniences seen in conventional devices.

[Structure of the invention]

(Means for solving the problems) In order to solve the above problems, the following measures were taken in the present invention.

(1) A small speed reduction motor (sub motor) was installed near the back of the arm of the sewing machine.

(2) A pinion gear was provided on the gear shaft of the small reduction motor.

(3) A rack that meshes with the pinion gear is installed to be movable up and down in a direction perpendicular to the main shaft of the sewing machine.

(4) A presser foot lifting plate that interlocks with the rack is disposed within the foot roller of the sewing machine arm.

(5) The sub-motor is operated by a control circuit in response to the sewing cycle and the operator's operations.

(Function) When the presser foot operation switch is turned on by operating the foot pedal or manual button, the sub-motor is started and the presser foot lifting plate is raised by the operation of the rack and pinion. This lowers the presser foot of the sewing machine.

When the presser foot operation switch is turned off, the sub-motor reverses to operate the rack downward and raise the presser foot of the sewing machine.

Next, when the presser foot operation switch is turned on and the start switch is turned on, the sub-motor starts to lower the presser foot, and then the sewing machine's drive solenoid is activated to start the sewing machine. Then, when the feed cam rotates and one cycle of sewing is completed, the sub-motor is activated and the presser foot is raised.

(Example) An example of the present invention will be described with reference to the attached FIGS. 1 to 3. In the figure, 1 is the sewing machine arm.

2 is the bed, 3 is the needle bar, 4 is the presser foot, and 5 is the presser foot arm.

6 is a lower presser foot, 9 is a presser foot 7-m, and 11 is a presser spring.

12 is a small reduction motor (hereinafter referred to as sub motor);
Reference numeral 15 indicates a rack, and reference numeral 16 indicates each member of a presser lifting plate.

As seen in FIG. 3, the sub-motor 12 is attached to the back side of the sewing machine arm 1. And its deceleration shaft 13
A pinion gear 13 provided at the tip of a is engaged with a blade portion 15a of a rack 15 that is pivotally supported by the arm 1. As is clear from FIG. 1-2, this rack 15 has a presser lifting plate 16 fixed to its lower end, and a stop washer 1 to its upper end.
7 is fitted and fixed with a nut 18. Further, a presser foot arm 5 is fixed onto the sewing machine bed 2 with screws 7 via a feed rod 20.

A presser foot 4 is attached to the cloth presser arm 5 so as to be movable up and down on the needle bar 3 side, and a presser foot arm 9 is loosely attached with a pin 10. One end of the presser foot 4 fits into the holding portion of the presser foot 4, and the other end is constantly biased counterclockwise by a presser spring 11.

The rotation of the rack 15 in the circumferential direction is restricted by an appropriate rotation stopper (not shown).

Now, when you turn on the presser foot operation switch, sub motor 1
2 starts to rotate the worm wheel 14, the pinion gear 13 rotates counterclockwise, and the rack 15 moves upward (Fig. 2). Therefore, the presser foot lifting plate 16 rises,
It separates from the contact piece 9a of the presser arm 9. At this time, the presser arm 9 is rotated counterclockwise by the pressure of the presser spring 11 to press the presser foot 4 against the bed surface. At this time, the power supply to the motor is turned off for a certain set time by the control circuit, so that the rack 15 is stopped at the upper limit.

Next, when the presser foot operation switch is turned OFF, the sub motor 12 is energized to reverse rotation, and the pinion 1 of the motor is turned OFF.
3 rotates clockwise to lower the rack 15. Therefore, the presser foot lifting plate 167 presses the presser arm 9, and the presser foot 4
to rise. And the rack 15 is the stop washer 17
When the motor stops at the lower limit, the power supply to the sub motor 123 is controlled to be in an OFF state. If you turn on the drive switch with the presser foot operation switch in the ON state, the sewing machine will operate as if the presser foot 4 is pressing the cloth, and one cycle of I
N! Manufacturing takes place.

When this sewing is completed, the sewing machine stops and the presser foot rises to complete the construction.

Next, the control circuit of the device of the present invention will be explained based on FIGS. 4 and 5.

That is, when only the presser foot is controlled up and down, as shown in Fig. 4,
For the lifting/lowering operation, turn on the presser foot lifting/lowering switch.

When turned off, the sub-motor drive switch rotates the motor 12 in the forward or reverse direction, thereby lowering or raising the presser foot.

Further, when the sewing machine is driven to perform one cycle of sewing, the control is performed as shown in the timing chart shown in FIG. That is,
When the presser foot lift switch is turned on, the sub motor 12 is rotated in the forward direction, and the presser foot 4 is lowered, the sewing machine drive switch is turned on at the same time.The clutch of the sewing machine is disengaged and the feed cam moves to 1-! ll cycle complete. During this time, the signal of the presser foot lift switch is maintained in the ON state, and when the feed cam rotates once and the sewing machine stops, an OFF signal is applied to the presser foot lift switch, and the sub-motor drive switch inputs a reverse rotation signal. Therefore, this causes the presser foot 4 to rise and the sewing is completed.

〔Effect of the invention〕

To achieve the same objective as the present invention, it is conceivable to operate the presser foot using a solenoid without using a motor. However, in the case of a bartack sewing machine, the presser foot is raised when the sewing machine is stopped, lowered during one cycle of sewing, and automatically raised when one cycle is completed. . Therefore, when a solenoid is used, the solenoid must be energized even during stoppage, which causes adverse effects such as temperature rise. Another method is to use the force of a solenoid to press the cloth and turn off the power to the solenoid so that the presser foot rises due to the action of a spring, but this makes it difficult to adjust the presser foot.

In the case of a solenoid, a fairly large and powerful one is required. However, in the case of the present invention, it is necessary to energize the motor only when raising and lowering the sewing machine, and there is no need to energize the motor during sewing, so the power consumption is small, and the sewing machine has unique advantages such as being small and having a strong working force.

Since the vertical movement of the rack is directly connected to the vertical movement of the presser foot, the clutch mechanism (
This also has the side effect of eliminating the need for power assist (power assist) and making it cheaper.

[Brief explanation of drawings]

FIG. 1 shows a device equipped with a presser foot lifting device (partial cross section) of the present invention.
Fig. 2 is a diagram of the lowering state of the presser foot when viewed from the front of the sewing machine; Fig. 2 is a diagram of the ascending state of the presser foot similar to Fig. 1; Fig. 3 is a diagram of the A-- of Fig. 1;
4 and 5 are diagrams showing timing charts of the control circuit, respectively. 1... Sewing machine arm, 2... Sewing machine bed.

Claims (1)

[Claims] In a cycle sewing machine, a small reduction motor, a pinion gear provided on the reduction shaft of the motor, a rack meshing with the pinion gear, a presser foot lifting plate connected to the rack, and controlling the operation of the small reduction motor Minshi's presser foot lifting device equipped with a control device.