JPS6018227Y2 - Sewing machine needle fixed position stop device - Google Patents

Description

[Detailed description of the invention] This invention is an electric sewing machine using a pattern generating cam.
This device relates to a device that automatically stops the sewing machine when the last stitch of a selected pattern is formed, and its purpose is to set the needle by forming only one selected pattern, that is, one cycle. When this option is selected, the switch is activated when the pattern generating cam reaches the rotational phase that outputs the final stitch of the pattern, and the sewing machine stops at the needle foot position. By operating the electromagnetic thread maid to enable and disable the mechanism and stop the needle at a predetermined position, for example at top dead center, the sewing machine can be automatically and reliably stopped at the last stitch of cycle sewing without the need for a stop operation. The purpose is to make it possible to repeat new cycle sewing in the same way.

Conventionally, in a sewing machine using a pattern generation cam, sewing is started from a state where the pattern cam is stopped at an undefined rotational phase, so the sewing start is at the coordinates of the first stitch forming one pattern. is not necessarily specified.

In addition, when creating a combination pattern by combining multiple identical or different patterns in arbitrary positional relationships, be sure to stop the sewing machine when one pattern is completed, and check the next pattern. It is preferable to prepare for the start, but stopping by operating a controller or the like poses problems such as overshooting and poor work efficiency.

This invention was devised to solve the above problem, and when one pattern cycle is completed, a switch is activated to cut off the power to the sewing machine motor, and an electromagnetic solenoid for stopping the needle foot position is activated. The sewing machine is stopped at the needle position, so that the next new cycle can be started from the coordinates of the first stitch of the pattern.

An embodiment of the present invention will be described below with reference to the drawings. 1 is the main body of the sewing machine, 2 is an upper shaft, and the rotation of the upper shaft is reduced by a ratio of 6:1 by a worm mechanism 3 and transmitted to a pattern generating cam shaft 4. There is.

Reference numeral 5 designates a pattern cam, which consists of a group of cams consisting of a plurality of strips for stitch information of a plurality of patterns.These cams are fixed to the cam shaft 4, and when a pattern is selected, a follower (not shown) is activated. is adapted to control the lateral runout of the needle by following one of the cam groups corresponding to the selected pattern.

Each pattern is made up of six stitches.

Note that the cloth feed control cam and these seam forming mechanisms are omitted from the drawing.

Reference numeral 6 denotes a circular pattern position detection cam, which has six tapered grooves 7 on its side surface, these grooves penetrating in the circumferential direction, and only one of them, ``care a'', has a large groove height. As will be described later, this is for cycle sewing, and the six grooves 7 including this are for single stitch sewing.

S is the sewing style selection cam, 9 is the release cam, and both are the selection cam axis 1.
0 and rotated by the sewing method selection dial 11, the follower 12 is engaged with the selection cam surface 8, and when it is locked on the minimum diameter cam surface A as shown in the figure, normal sewing is performed. is selected, and when the dial 11 is rotated 90 degrees clockwise and it locks on the intermediate diameter cam surface B, cycle stitching is selected, and when the dial 11 is further rotated 90 degrees and it locks on the maximum diameter cam surface C, one stitch is selected. The needle edge is now selected.

The follower 12 is attached to the phase detection arm 1 to which it is fixed.
3 is moved left and right in FIG. 1 according to the diameters of the cam surfaces A, B, and C, and the detection pin 14 fixed thereto is moved left and right.

Reference numeral 15 denotes a spring that urges the arm 13 to the left in FIG.

The arm 18 is pivotally mounted on the shaft 16 and biased counterclockwise in FIG. 2 by a spring (not shown), and the arm 18 is
2 is locked to the cam surface B, the pin 14 will fit into the groove 7a.
When they match, the arm falls into the groove and rotates the arm 13 counterclockwise.

Similarly, if the cam surface C is locked, the groove 7 including the groove 7a
Rotate each time they match.

When the cam surface A is as shown in FIG. 1, it will not fall into any groove.

SW□ is a sewing force selection changeover switch whose actuator 17 is activated by the movement of the actuating piece 18 of the phase detection arm 13 in the axis 16 direction, and detects whether the follower 12 is on the cam surface A, cam surface B or C. Switch.

SW2 is a pattern position detection changeover switch, whose actuator 19 is activated by rotation of the actuation piece 18, and the pin 14
It detects whether or not it has fallen into the groove 7 and switches.

Reference numeral 20 denotes a release arm, and the peak of the release cam 9 passes over the release pin 21 attached to the release arm each time the sewing method is changed, and when the detection pin 14 is in the groove 7,
It acts on the phase detection arm 13 to once remove it from the groove and then switches the sewing method.

A pulley 22 receives the driving force of a sewing machine motor (not shown) via a belt 23.

A stopping cam 24 is fixed to the upper shaft 2, and when the corner 27 of the locking pawl 26 engages with the locking portion 25, the cam stops the upper shaft 2 rotating in the direction of the arrow in the figure. The locking pawl 26 is pivotally supported by a screw 28 and is connected to a plunger 30 of an electromagnetic solenoid SQL via a link 29, so that when the solenoid is energized, the locking portion 26 is forcibly stopped. 25, and when not energized, it is positioned outside the orbit by a spring 31, as shown in FIG.

The solenoid is also de-energized during normal operation of the sewing machine so that a de-clutch device (not shown) transmits the rotation of the pulley 22 to the upper shaft 2, but when it is energized to stop the sewing machine, it is de-energized to the de-clutch device (not shown). Operates and pulley 2
The transmission of the rotation of No. 2 to the upper shaft 2 is removed.

FIG. 4 is a control circuit diagram, where ■ is an AC power supply, M is a sewing machine motor, and C0NT is a resistance wire type controller.

When the aforementioned sewing method selection switch (SWl) selects normal stitching in which the follower 12 is engaged with the cam surface A of the sewing method selection cam 8, its contact piece t becomes the contact point a side, and the contact piece t becomes the contact point A side, and the cam surface B or C is When this happens, it becomes the contact side.

The diode D□ is for half-wave rectifying the current of the motor M to reduce its rotational speed, and in particular, constitutes a rotational speed reducing device together with the switch SW1.

In the pattern position detection switch SW2, when the detection pin 14 does not fall into any of the grooves 7 of the pattern position detection cam 6, its contact piece t is on the contact a side, and when it falls on either side, it is on the contact side. Become.

Therefore, during normal sewing in which the follower 12 is engaged with the cam surface A, the contact point is always on the a side, and during cycle sewing in which the follower 12 is engaged in the cam surface B, the contact point is once per revolution of the cam 6, that is, the contact point is on the side of the contact point a. 1 with a needle
This is the side that makes contact only in the needle foot phase, and this detects the end of the final stitch consisting of six stitches.

In other cases, the contact is on the a side.

When sewing a single stitch that locks onto the cam surface C, the contact point is the side that contacts the needle foot phase once per rotation of the cam 6, that is, every stitch, and in other cases, the contact point is the side a.

RL is a relay coil, and contact piece t of switch SW□ is contact a.
When the controller C0NT is operated from the side to the contact side, it is excited for a certain short time via the diode D2 and the capacitor C3.

The excitation time is based on the reaction and resistance of the coil RL and capacitor C.

R is the discharge resistance of the capacitor C□ when the controller C0NT is released.

The electromagnetic thread maid SQL has one end connected to the diode D.
The other end is connected to the contact a of the switch SW1 via the normally closed switch SW3, which is opened by the operation of the relay RL.

SW is a normally closed switch that is closed by the operation of relay RL, and then short-circuits contact t and contact a of switch SW2.

In the above configuration, when normal sewing is selected by the sewing method selection dial 11 so that the follower 12 of the cam surface A of the sewing method selection cam 8 is locked, the sewing force selection changeover switch SW□
The contact piece t is on the contact a side, and the detection pin 14 has moved to the left side as shown in FIG. The contact is always on the a side, and the speed of the sewing machine motor M is controlled by the controller C0NT, and the electromagnetic solenoid SQL is de-energized, so the pulley 22 and upper shaft 2 are coupled, and the sewing machine is operated under normal speed control. Ru.

Next, when cycle sewing is selected so that the follower 12 of the cam surface B of the sewing method selection cam 8 is engaged, the contact piece t of the sewing method selection switch SW1 becomes the contact side, and the detection pin 14
In the figure, it is located at an intermediate position between left and right movement, and is capable of falling into the groove 7a.

The contact piece t of the switch SW2 is on the contact a side except when the groove 7a is aligned with the pin 14, and at that time, the speed of the sewing machine motor M is controlled by the controller C0NT, and the maximum speed is reduced by the diode D□. driven.

When the controller C0NT is operated, the relay coil RL is temporarily excited to open the switch SW3 and close the switch SW4.

The opening and closing operations of these switches do not affect the operation of the sewing machine when 117a and pin 14 do not match, but
When they match, that is, when the contact piece t of the switch SW2 is on the contact side, the circuit of the solenoid SQL is cut off, the circuit of the motor M is enabled, and the motor is rotated, and the pin 14 escapes from the groove 7a, i.e. The relay RL is operated until the contact piece t becomes the contact point a side, thereby making it possible to start the sewing machine.

When the stitches of the pattern are formed and the pin 14 matches the groove 7a, the contact piece t of the switch SW2 becomes the contact side, and the current of the motor M is cut off.At this time, the capacitor C□ has been charged, so the relay is activated. RL does not operate (therefore, the solenoid SQL operates, the pulley 22 and the upper shaft 2 are disconnected, and the inertial force of the motor M is no longer transmitted to the upper shaft 2, so that they are not engaged in the rotation phase shown in Fig. 2). The local portion 27 of the stop claw 26 comes into contact with the locking portion 25 of the stop cam 24, and the sewing machine stops.

This stop position is set, for example, when the needle is on the verge of death.

Thereafter, by releasing the controller C0NT once to discharge the capacitor C□, and operating the controller again, the pattern will start from the first stitch, form the last stitch, and then stop; however, at the beginning of sewing, If the pin 14 is not aligned with the groove 7a, in this embodiment, the cam 6 may be fed by rotating the motor M until the pin 14 is aligned with the groove 7a before attaching the cloth to the sewing machine.

When single stitch sewing is selected so that the follower 12 of the cam surface C of the sewing method selection cam 8 is locked, the detection pin 14 moves to the right in FIG. 1 and can fall into the six grooves 7. I have to.

While cycle sewing stops every six stitches, single stitch sewing is performed, which stops at the needle top dead center every stitch and starts when the controller C0NT is operated.

As described above, according to the present invention, cycle sewing can be performed with reliable operation, contributing to improvement of work efficiency, and the construction is simple and operation is reliable, making it a useful invention.

[Brief explanation of drawings]

FIG. 1 is a schematic front view of a sewing machine mechanism showing an embodiment of the present invention, FIGS. 2 and 3 are a side view and a top view thereof, and FIG. 4 is a control circuit diagram. In the figure, 5 is a pattern generation cam, pattern position detection cam 6 is the main element of the pattern position detection device, M is the sewing machine motor, SOL is the electromagnetic solenoid, sewing style selection dial 11 is the main element of the sewing force selection device, and switch SW2 is the main element of the sewing force selection device. The switching device, the capacitor C, the relay RL, and its switches SW3 and SW4 are the elements constituting the reset device.

Claims (1)

[Scope of utility model registration request] In an electric sewing machine equipped with a pattern generation cam that rotates via a speed reduction mechanism in conjunction with rotation of an upper shaft, a pattern position detection device detects a predetermined phase of one revolution of the upper shaft and/or the predetermined phase every predetermined integer rotation of the upper shaft. a declutching device including an electromagnetic solenoid for engaging and disengaging the transmission of the driving force of the sewing machine motor to the upper shaft and stopping the sewing machine at the needle position; a sewing method selection device for switching the detection device between activation and non-activation; the sewing method selection device connects the solenoid to a power source; and when the pattern position detection device detects the predetermined phase, the sewing machine motor circuit is cut off; When the sewing machine motor is started, the switching device that switches the declutch device to the needle foot position stop function side by the action of the solenoid and the pattern position detection device are operating to detect a predetermined phase. A needle foot position stopping device for a sewing machine, which is provided with a reset device that makes the declutch device a transmission side to the upper shaft by the action of the solenoid, and restores the disconnection of the sewing machine motor circuit.