JPS5953073B2 - cycle sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention lowers the presser foot in conjunction with a unidirectional initial operation of a single operating means, starts the sewing machine by a unidirectional late operation, and starts the sewing machine after forming a predetermined number of stitches. The present invention relates to a cycle sewing machine that stops, and particularly relates to a cycle sewing machine having a presser foot that is brought into a lowered state by only a short initial operation of a single operating means and then raised when the sewing machine stops.

Conventionally, in a cycle sewing machine having a presser foot mechanism as described above, the sewing machine is started when moving from one position to the other position, and the presser foot is started when moving to an intermediate position between both positions. After lowering the presser foot, the control means is moved from one position to the other position beyond an intermediate position by depressing a pedal mechanically connected to the control means. I was trying to start the sewing machine, but this pedal operation
In order to return the control means from the other position to the one position, it is necessary to do so against the elastic force of the elastic means provided in the control means, which increases the burden on the operator when depressing the pedal and causes fatigue. There were drawbacks such as giving.

Also, when lowering the presser foot without starting the sewing machine to thread the needle or position the fabric to the seam,
It is necessary to move the control means to an intermediate position so as not to move it to the other position, and it is necessary to carefully adjust the load in order to depress the pedal to the intermediate position, which has disadvantages such as lowering work efficiency. If the amount of treading is erroneously excessive, the sewing machine may operate involuntarily, causing uneasiness to the operator, leaving needle drop marks on the fabric, and deteriorating the quality of the product.

The present invention aims to eliminate the above-mentioned conventional drawbacks.

An embodiment of the present invention will be described with reference to the drawings. Holding parts 2 and 3 are formed protruding from both sides of the upper surface of a support base 1 fixed to a sewing machine frame (not shown), and a horizontal shaft 4 is formed in the holding parts 2 and 3. is supported rotatably around its own axis.

A lever 6 whose base end 5 is fixed to the horizontal shaft 4 has a distal end 7 connected to an electromagnetic device Mg (third
It is connected to the plunger shown in the figure), and when the electromagnetic device is energized, it is pulled by the plunger to rotate the horizontal shaft 4 in the direction of the arrow.

An actuating body 9 fixed to an axially intermediate portion of the horizontal shaft 4 is capable of engaging a presser lifting device (not shown) by rotating the horizontal shaft 4 in the direction of the arrow at the tip of a protruding portion 10 that projects upward.
Upon engagement, the lifting device operates to lower the presser foot onto the throat plate.

The actuator 11 fixed to the axial end of the horizontal shaft 4 forms a protrusion 12 that protrudes upward by a predetermined angle of rotation in the direction opposite to the arrow from the protrusion 10 of the actuator 9 with respect to the horizontal axis. The tip of the portion 12 can be engaged with a starter device (not shown) when the horizontal shaft 4 further rotates in the direction of the arrow after the protruding portion 10 of the operating body 9 engages with the lifting device, and the sewing machine is activated by engagement. The starting device operates so that the driving state is set and one predetermined cycle of driving is performed.

The engaging portion 13 provided at the lower end of the starting body 11 has a coiled spring (not shown) having an elastic force that locks one end to the sewing machine frame and always rotates the starting body 11, that is, the horizontal shaft 4 in the direction opposite to the arrow. )
A pin 14 is provided for locking the other end, and when rotating counterclockwise, the engaging portion 13 engages with a locking body 15 fixed to the sewing machine frame, and each protrusion of the starting body 11 and the actuating body 9 The tip of the portion 10°12 is locked in a rotational position such that it is separated from the starting device and the lifting device.

Next, the electric circuit will be explained.

A direct current obtained by rectifying and smoothing an alternating current wave is applied between terminals a and l).

MSW is a start switch provided on the pedal of the sewing machine, and the 1st cycle is closed by depressing the pedal.

PUT turns on when the anode A potential becomes higher than the gate G potential. It is a thyristor, and the output at its cathode becomes the base input of the nPn type transistor Trl.

Z is a drive circuit for energizing the electromagnetic device Mg, and when the transistor Tr1 is turned off, a starting switch M is activated.
When the current from SW is input to the bases of transistors Tr2 and Tr2 and the transistor Tr3 whose base input is the emitter output of Tr2 is turned on, the electromagnetic device M is turned on.
The current that energizes g becomes the collector input of Tr2 and Tr3.

Y is a selection circuit, which includes a series resistor R1 and a variable resistor VRI.
contact d connected to and series resistor R2, variable resistor VR2
A contact e connected to is provided in parallel, and a manual switch SSW that can be connected to one of contacts d and e is provided.

The fixed contact of this SSW is connected to the negative side of a capacitor C connected between the gate 1-G of the PUT and the starting switch MSW.

Then, the combined resistance value of resistors R1 and VRI is determined by turning on the start switch MSW and charging the capacitor C.
Attaching an electromagnetic device that rotates the horizontal shaft 4 until the tip of the protrusion 10 of the actuating body 9 engages with the lifting device after a decay time Δt1 until the gate G potential falls from the anode A potential. The resistance value is set to control the charging time of the capacitor C so that the charging time of the capacitor C is maintained.

Furthermore, the combined resistance value of the resistors R2 and VR2 is determined by the attachment of an electromagnetic device that rotates the horizontal shaft 4 until the tip of the protrusion 12 of the starter 11 engages with the starter after a similar decay time Δt2. The resistance value is set to control the charging time of the capacitor C so that the charging time of the capacitor C is maintained.

This invention has the above configuration, and the selection switch SS
When W is connected to terminal d and then the starting switch MSW is turned on, a current is applied to capacitor C and a voltage is generated between both terminals, and the gate G potential of PUT becomes higher than the anode A potential, and PUT turns off. hold, resistor R1, VRI
The capacitor C is gradually charged over the time set by , and the gate G potential attenuates and becomes lower than the anode A potential after Δt1 has elapsed, and PUT is turned on.

During this Δt1, the transistor Trl is off,
The current from MSW becomes the base input of the transistor Tr2 and turns on the drive circuit Z, and the electromagnetic device Mg is energized to pull the lever 6. Rotate □ in the direction of the arrow until it engages, and the presser foot descends onto the throat plate.

When PUT is turned on after △t1, the transistor Tr
1 turns on and cuts off the base input of Tr2, and the drive circuit Z
is turned off to deenergize the electromagnetic device Mg, the pulling of the lever 6 is released, and the horizontal shaft 4 returns in the direction opposite to the arrow by the elastic force of the coiled spring.

Next, when the selection switch SSW is operated to the terminal e and the start switch MSW is turned on, the capacitor C is gradually charged over the time set by the resistor R2°VR2, and after Δt2 has passed, the potential of the anode A of PUT is higher than that of the capacitor C. The gate G potential becomes low and PUT is turned on.

Since the PUT is off during Δt2, the drive circuit Z is turned on, and the electromagnetic device Mg is energized to pull the lever 6, and the horizontal shaft 4 is moved so that the tip of the protrusion 10 of the operating body 9 engages with the lifting device. Rotate in the direction of the arrow until the
The protrusion 12 is rotated until the tip of the protrusion 12 engages with the activation device.

As a result, after the presser foot is lowered onto the throat plate, the sewing machine enters the driving state, and -cycle stitch formation is performed.

After Δt2 has elapsed, PUT is turned off, the drive circuit Z is turned off, the electromagnetic device Mg is deenergized, and the horizontal axis 4 returns to the opposite direction of the arrow.

As described above, according to the present invention, the sewing machine is always maintained at one position by elastic force, starts up in conjunction with movement from one position to the other position, and moves from one position to an intermediate position between both positions. energizing a single electromagnetic means in connection with operation of one of the operating means, such as a pedal, in a cycle sewing machine having a control means for lowering a presser foot in a raised position in connection with the operation of the presser foot in a raised position; Since the control means can be moved from one position to the other position beyond the intermediate position, the operator only needs to lightly press the operating means, which makes the work easier and reduces worker fatigue, increasing efficiency. It has the effect of improving

In addition, the excitation time of the electromagnetic means can be changed to a longer or shorter time by operating a manual switch, and when excitation is performed for a long time, the control means is moved to the other position, and when excitation is performed for a short time, the control means is moved to an intermediate position. Therefore, when lowering the presser foot without starting the sewing machine in order to thread the needle or position the fabric to be sewn before starting the sewing machine, we changed the manual switch so that the operating means would be energized for a short time. Since it is only necessary to operate the operating means normally, the operation of the operating means is simple and easy, which improves work efficiency, and the sewing machine is not started due to the control means being moved to the other position by mistake, so the operator can feel at ease. It has the effect of improving the quality of the product without forming unwanted needle drop marks on the fabric.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the control means of this embodiment, FIG. 2 is a side view of the starter and actuator fixed to the horizontal shaft 4, and FIG. 3 is an electric circuit. In the figure, 4. 6. 10. 12 is a control means, M
SW is an operating means, Mg is an electromagnetic means, R1 and VRI are a first circuit, R2 and VR2 are a second circuit, and S and SW are selection switches.

Claims (1)

[Claims] 1. When the sewing machine normally receives a downward elastic force, it moves to the raised position against the elastic force when the sewing machine stops, and the rimming machine is started by the locking presser foot and pressing operation, and the sewing machine starts after forming a predetermined number of stitches. In a cycle sewing machine that has a drive mechanism that stops the presser foot, the elastic force is always used to move the drive mechanism away from one position and press the drive mechanism, and to the intermediate position that is located between the two positions and releases the presser foot. A control means that is movable against a force, an operation means that generates an actuation signal in response to manual operation, and a bias that pulls and moves the control means from one position to the other position. an electromagnetic main stage connected to the control means, and a main stage for supplying an energizing current so as to generate an electromagnetic force in the electromagnetic means corresponding to the elastic force at an intermediate position of the control means in connection with generation of an actuation signal from the operating means. - a second circuit for supplying an energizing current so as to generate an electromagnetic force in the electromagnetic means corresponding to the elastic force in the circuit and the other position; and a selection switch operable to connect the electromagnetic means to one of the circuits; A control device for a sewing machine, comprising an electric circuit and an electric circuit.