JPH0518597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a sewing product feeding device used in a sewing machine.

[Conventional technology]

Generally, a sewing machine is provided with a cloth feeding device that feeds cloth in synchronization with the vertical movement of a needle. Industrial sewing machines have various problems that are different from general household sewing machines, so the Japanese Patent Publication No. 57-30518
As disclosed in the above publication, a cloth feeding device has been proposed in which rollers facing each other are provided and one of the rollers is driven by a motor.

[Problem that the invention seeks to solve]

However, in such conventional devices, one roller is driven by a motor, but the other roller is rotated by friction with the cloth, and since the roller has inertia, The rotational speeds of the upper and lower rollers do not match when starting and stopping feed, and for this reason, in industrial sewing machines that feed at high speeds, when sewing thin fabrics, This has the disadvantage that the stitches at the start and stop times are different from other parts, resulting in uneven stitches.

The present invention has been made to solve these problems, and an object of the present invention is to provide a sewing product feeding device that can uniformly feed a sewing product.

[Means for solving problems]

In order to solve these drawbacks, this invention
Motors are provided independently for the upper and lower rollers, and the number of rotations of these motors can be controlled arbitrarily.

[Effect]

The upper and lower rollers are driven simultaneously and independently.

〔Example〕

FIG. 1 is a perspective view showing a schematic configuration of a sewing machine to which the present invention is applied. In the figure, an upper shaft (main shaft) 2 that is rotationally driven by a driving force 1 is provided with a timing belt pulley 3 that rotates integrally with the upper shaft 2. is driven, and the rotation of the upper shaft 2 is transmitted to the lower shaft 5. As a result, gears 15,1
6 rotates, and the rotation is transmitted to the hook 17.
On the other hand, the rotation of the upper shaft 2 is transmitted to the needle bar 10 by the crank 6, the balance 7, the connecting rods 8, 9, etc., and causes the needle bar 10 to move up and down. Cloth feeding rollers 13 and 19 are provided facing each other near the needle bar 10, and the lower roller 19 rotates together with the shaft of a pulse motor 18 provided near the roller 19. The upper roller 13 is configured to be able to move up and down, and is urged downward via a connecting rod 14 by a spring (not shown). Also, the upper roller 13
is rotatably driven by a pulse motor 11 provided near the upper shaft 2 via a timing belt 12. A needle position sensor 20 generates a signal representing the needle position based on the rotation of the upper shaft 2.

FIG. 2 is a block diagram showing an example of a device for driving pulse motors 11 and 18 that rotate rollers 13 and 19. In this device, when a pedal is depressed and a pedal switch 30 interlocked with the pedal switch is turned on, a signal for performing a reference operation of the sewing machine is transmitted from a sewing machine control circuit 31 to signal generating circuits 32a and 32b and a needle drive circuit 33. As a result, the signal generation circuits 32a and 32b are connected to the pulse motors 11 and 1.
A pulse signal is generated to drive rollers 8 to rotate cloth feeding rollers 13 and 19 at the same speed in opposite directions. Then, the needle drive circuit 33 brings a clutch (not shown) into contact, and converts the driving force 1 into rotational motion to the upper shaft 2 and the crank 6.
This allows the needle bar 10 to move up and down. Here, when the idle feed switch 34 is turned off, the clutch becomes in a non-contact state, and the needle bar 10 does not move and only the rollers 13 and 19 rotate.
In other words, only the cloth is fed and no sewing is performed, resulting in a state of idle feeding. In addition, the rollers 13, 1 during sewing
The feeding of the needle 9 is performed in synchronization with the vertical movement of the needle based on a signal from the needle position sensor 20.

The rotation direction switching circuits 35a and 35b switch the pulse motors 11 and 1 when the reverse sewing switch 36 is turned on.
As a result, the direction of rotation of the pulse motors 11 and 18 is reversed, and backward sewing is performed.

The number of pulses generated from the signal generating circuits 32a and 32b is determined by the signal supplied from the sewing machine control circuit 31 and the signal supplied from the speed control circuit 38, and is synchronized with the vertical movement of the needle. Further, when the differential stitching switch 37 is off, the speed control circuit 38 operates on the signal generating circuits 32a and 32b.
The number of pulses generated from the sewing machine control circuit 31 is the same, and the number of pulses is determined by the signal supplied from the sewing machine control circuit 31. However, when the differential sewing switch 37 is on, the signal generation circuits 32a and 32b
The number of pulses generated can be set independently. For this reason, the pulse motors 11, 18
By setting the rotation speed of the upper and lower rollers to different values, the rotation speed of the upper and lower rollers can be changed, for example, when sewing a hard, undeformable material such as the heel of a shoe, and a curved surface. Sewn items can be sent in optimal conditions.

〔Effect of the invention〕

As explained above, in this invention, the opposing rollers are driven independently by motors, so the upper roller and the lower roller can be driven simultaneously and independently, which allows for smooth feeding of the sewing material. It has the effect of being able to.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a sewing machine to which the present invention is applied, and FIG. 2 is a block diagram showing an example of a device for driving rollers. 10... Needle bar, 11, 18... Pulse motor,
12...Timing belt, 13, 19...Roller, 30...Pedal switch, 34...Jump feed switch, 36...Reverse stitching switch, 37...Differential stitching switch.

Claims (1)

[Claims] 1. A roller for feeding the sewn product provided opposite to each other in a position close to the needle, a motor for driving the roller provided for each roller, and said motor being driven at a predetermined speed corresponding to the number of rotations of the sewing machine. A sewing material feeding device comprising: a signal generating circuit that generates a signal for driving the sewing material; and a speed control circuit that controls the motor speed so that the difference in motor speed is an arbitrary value.