JPS61100292A - Yarn loosening machanism of cycle 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) The present invention relates to a thread loosening mechanism for a lockstitch cycle sewing machine such as a lockstitch button sewing machine.

(Prior Art) In the thread loosening mechanism of a sewing machine for attaching a lockstitch button, it is required that the thread loosening end time be after the thread take-up has reached the top dead center. Otherwise, the length of the thread coming out of the needle thread (needle thread) will be insufficient in the state of the first stitch at the start of the next cycle, and the thread length will be insufficient before the needle reaches the fabric. This is because the needle will come out of the needle hole and sewing will not be possible.

In order to meet this demand, conventionally the 7-lenoid was operated at an appropriate time to complete the thread loosening process.

(Problems to be Solved by the Invention) However, in order to operate the solenoid at an appropriate time, a separate control device must be provided, and it is difficult to synchronize the control device with one cycle of the sewing machine. I couldn't stand the trouble. The present invention aims to provide a thread loosening mechanism that eliminates such problems.

[Structure of the invention]

(Means for Solving the Problems) Therefore, the present invention provides a stitch number adjustment wheel that rotates once per cycle and issues a thread loosening operation signal, and a thread loosening arm that swings downward in response to the signal from the adjustment wheel. , a thread loosening cam having a protrusion linked to the rotation of the adjustment wheel, capable of being lowered in synchronization with the downward swing of the thread loosening arm, and being attracted to the thread loosening arm by a spring; From the start operation when the protrusion of the thread loosening cam is in contact, the protrusion rotates to an angle approximately 30 degrees behind the angle of the needle at the start position, and synchronizes with the descent of the thread loosening arm until it comes off. However, when the protrusion comes off, the mounting plate is raised by the spring independently of the thread loosening arm, the lever is operatively connected to the thread tension disc, and the lever is interposed between the mounting plate and the lever. The lever rotates in one direction in conjunction with the mounting plate that descends in synchronization with the thread loosening arm to open the thread tension disc, and is independent of the thread loosening arm of the mounting plate. When the lever is raised to its original position, the lever returns to its original position and the thread tension plate closes.This is a means for solving the problem.

(Function) Now, when the sewing machine is started when the protrusion of the thread loosening cam is in the start operation, that is, when the protrusion is in contact with the tip of the installation plate, the thread loosening cam rotates. At a certain angle of the protrusion (that is, approximately 30 degrees behind the angle of the needle at the starting position), the contact is broken and the mounting plate is moved upwards by the biasing force of the spring, and the transmission means is activated. Then, return the thread release lever to its original position, and apply tension to the thread by pinching it between the thread tension discs.

(Embodiment) Below, an embodiment of the present invention will be explained with reference to the drawings. Figs. This is a stitch number adjustment wheel installed in the section that determines the number of stitches required for one cycle of a cycle sewing machine, and rotates once per cycle of the sewing machine. A thread loosening arm 5 is attached to the stop motion bin 1, and starts thread loosening operation when the needle is at 270 degrees (3i4 times) in the last rotation at the end of one cycle.

The thread loosening operation signal is generated when the thread loosening arm 5 swings downward around the bin 1 when the roller 4 attached to the stop arm 2 enters a groove (not shown) on the outer periphery of the stitch number adjustment wheel 3. The thread cutting link 18 connected to the tip of the thread loosening arm 5 with a set screw 11 also moves downward. A thread trimming connecting lever 2o is connected to the lower end of the thread cutting link 18 by a set screw 11a, and when the thread loosening link 18 is lowered downward, the connecting lever 2° also rotates clockwise about the shaft 20a. .

A cable end mounting plate 19 is attached to the connecting lever 20 with a set screw llb, and the cable end mounting plate 19 is attached to the thread loosening arm 5.
It is lifted up by a spring 9.

Further, the position of the cable end mounting plate 19 can be adjusted by loosening the position adjusting nut 16 and turning the position adjusting screw 17. 10 is a thread loosening wire, and a cable end mounting plate 19
and the thread loosening lever 29, and the lower end is connected to the cable end mounting plate 19 using the cable end 15 and the nut 12.
is fixed.

When the thread loosening wire 10 is pulled to the right in FIG. 3, the thread loosening lever 29 rotates clockwise about the thread loosening lever shaft 21. The thread loosening bin 27 is in contact with the tip of the thread loosening lever 29, and when the convex portion 29a of the thread loosening lever 29 descends, the thread loosening bin 27 is in contact with the tip of the thread loosening lever 29.
is pushed to the right.

Reference numeral 28 denotes a thread tension device, and one movable plate presser 36a is fixed to a bottle 28a passing through it.
a is pressed against a fixed thread tension plate 36 by a spring 37. Further, the tip of the bin 28a is in contact with the thread loosening bin 27. Here, when the thread loosening bin 27 is pushed out to the right, it is pushed to the right against the thread tension disc 36al11 spring 37 via the bin 28 &, and the tension on the thread between the thread tension disc 36 and disc presser 36 & is lost. , the thread loosens and begins to open.

Next, the state at the end of thread loosening and opening is the state during the next one cycle start operation, that is, the state in which the thread loosening arm 5 attached to the stop motion table bin 1 moves upward. 6 is a feed cam shaft 8 to which the stitch number adjustment wheel 3 is attached.
The cam 6 also rotates once per cycle, similar to the stitch number adjustment wheel 3, and the cam-shaped protrusion 6a is attached to the upper surface of the cable end mounting plate 19 during the start operation. 19&, when the sewing machine starts, the thread loosening cam 6 rotates in the direction of the arrow in FIG. The cable end attachment plate 19 is moved upward by the restoring force of the cable end spring 9, and the thread loosening wire 10 is loosened.

Thread loosening lever 29 connecting the thread loosening wire 10
A spring 26 is installed in the thread loosening wire 1.
0 is loosened, the thread loosening lever 29 moves to the left by the restoring force of the spring 26, and the thread loosening lever 29 at the tip of the lever 29 moves to the left.
7 is also pushed against the bottle 28a by the spring 37 and returns to its original position because it is guided by the frame, so the plate presser 36 &
is pressed against the thread tension plate 36 by the pressure of the thread tension spring 37, applying tension to the thread, and the thread is in the state of being at the end of loosening and opening. In addition, in the figure, 24 and 25 are stop rings, 31 is a thread loosening cable bushing, 32 is a thread loosening set screw, and 33
is a thread loosening cable, 34 is a thread loosening wire support, 35
It is a set screw. Note that a link mechanism may be used instead of the wire 10.

〔Effect of the invention〕

The present invention is constructed as described above in detail.
Therefore, the opening timing of the thread loosening start and the opening end timing of the thread loosening can be set at the same timing as the operating timing of the thread cutter catcher, and the opening end can be freely set at the timing after the top dead center of the balance. Furthermore, in the present invention, the thread loosening operation signal is received from the stitch number adjustment wheel that rotates once per cycle, eliminating the need for a llenoid or the like as a signal source, and there is no risk of the needle thread being pulled out of the needle. , the length of the thread at the beginning of sewing can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the lower part of the wire in a thread loosening mechanism showing an embodiment of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a side view of the upper part of the wire, and FIG. 4 is a front view of the same. FIG. 5 is a front view of the main parts in FIG. 3. Explanation of the main parts of the diagram 3... Stitch number adjustment wheel 5... Thread loosening arm 6...
・Thread loosening cam 6a...Protrusion 10...Transmission means (wire) 19...Mounting plate 29...Thread loosening lever 36...Thread tension disc 36a...Dish holder

Claims (1)

[Claims] A stitch count adjustment wheel that rotates once per cycle and issues a thread loosening signal, a thread loosening arm that swings downward in response to the signal from the adjustment wheel, and a thread loosener that has a protrusion that is linked to the rotation of the adjustment wheel. The cam can be lowered in synchronization with the downward swing of the thread loosening arm, and is attracted to the thread loosening arm by a spring, from the start operation when the protrusion of the thread loosening cam is in contact with the cam. The projection rotates to an angle approximately 30 degrees behind the angle of the needle at the starting position, and synchronizes with the descent of the thread loosening arm until it comes off, but when the projection comes off, the spring causes the thread loosening arm to move downward. a mounting plate that rises independently of the lever, a lever operatively connected to the tension plate;
A transmission means is provided between the mounting plate and the lever, and the lever is rotated in one direction in conjunction with the mounting plate that descends in synchronization with the thread loosening arm, and the thread tension disc is rotated in one direction. The thread loosening mechanism for a lockstitch cycle sewing machine is characterized in that when the lever is opened and raised independently of the thread loosening arm of the mounting plate, the lever returns to its original position and the thread tension disc closes.