JPH06254274A - Stitch balancing thread tension device-releasing device for sewing machine - Google Patents

Abstract

PURPOSE:To hold a stitch balancing thread tension device under a non-operating condition even when a holder lifting lever is lowered as long as the holder lifting lever is raised at one point when a thread is set by providing an operation cam which synchronizes with a main shaft and has positions to put the stitch balancing thread tension device under the operating and non-operating conditions, and a holding means to hold the stitch balancing thread tension device under a non-operating condition. CONSTITUTION:An operation cam 3 which synchronizes with a main shaft 1 and has two positions to put tension discs 21, 23 under a operating and non-operating conditions, and a release claw 13 which is operated by the operation cam 3 and holds the tensions discs 21, 23 under the non-operating condition are provided. When a thread is set, the main shaft 1 is rotated by putting in and out of a cloth, a needle tip is lifted higher than a throat plate, and a holder lifting lever 45 is raised at one point. By doing these motions, even when the holder lifting lever 45 is lowered, the tension discs 21, 23 are held open and under the non-operating condition. The tension discs are held under the non-operating condition until a needle hole moves under the throat plate. For this reason, a thread is assuredly inserted between the tension discs 21, 23, and a thread setting can be performed without a mistake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thread tension releasing device for a sewing machine.

[0002]

2. Description of the Related Art Conventionally, a thread tension regulator releasing device of a sewing machine is operated in conjunction with operating a lifting lever up and down. Therefore, when hooking the upper thread, rotate the main shaft to make the needle hole above the needle plate, raise the presser lever, put the thread tension gauge in the inactive state, and insert the thread into the thread tension disc of the thread tension gauge. , Threaded through the needle hole.

[0003]

However, when the operator neglects to raise the press-up lever and lowers the press-up lever, that is, when the upper thread is hooked while the thread tensioner is in operation, the thread is threaded. The thread tension disc is not inserted securely,
When sewing was performed as it was, the tension of the thread was weak and a satisfactory seam could not be obtained.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to rotate a main shaft by taking out and putting in a cloth to hold a needle tip above a needle plate when hanging a thread. Once you raise the gore lever, even if you lower the hold lever, the tensioner will remain inactive, the spindle will rotate, and the needle hole will move to the bottom of the needle plate.
It is an object of the present invention to provide a thread tension regulator release device for a sewing machine, which is capable of holding the thread tension regulator in an inoperative state.

[0005]

To achieve this object, the thread tensioning device opening device of the sewing machine of the present invention is synchronized with the main shaft and has two positions for activating and deactivating the thread tensioning device. And a holding means which is operated by the operation cam and holds the thread tension regulator in an inactive state.

[0006]

In the thread tension releasing device of the present invention having the above-described structure, when the thread is hooked, the pressing lever is once raised to take in and out the cloth, and the thread tension is maintained even if the holding means lowers the lifting lever. The container is kept in the inoperative state, and the thread is surely inserted into the thread tension disc even when the upper thread is hooked.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

A main shaft 1 is rotatably attached to a sewing machine main body (not shown), and a needle (not shown) reciprocates with a needle plate (not shown) in synchronism with the rotation of the main shaft 1. To do.
An operating cam 3 is fixed to the main shaft 1, and the cam shape of the operating cam 3 is as shown in FIG.
Has one position. The release lever shaft 5 is fixed to a sewing machine main body (not shown), and the release lever 7 is rotatably attached. A pin 9 is fixed to the tip of the opening lever 7 and engages with the operation cam 3. An opening claw 13 is rotatably attached to the opening lever 7 by a caulking shaft 11. The opening claw 13 has a cam-shaped portion,
A spring 15 is attached to press against the 7a portion of the opening lever 7. The other end of the spring 15 is attached to the sewing machine body (not shown). The thread tension plate 17 is attached to the sewing machine body (not shown), and the thread tension shaft 19 is fixed.

Further, the thread tension shaft 19 has a thread tension disc 21,
23, the dish retainer 25, the dish retainer 27, the dish release lever 29, the thread tension spring 31, and the spring retainer 33 are inserted in the order described. Then, the thread tension shaft 19 and the thread tension discs 21 and 21.
3, plate holder 25, plate holder 27, plate release lever 2
9, the thread tension spring 31, the spring retainer 33 and the like constitute a thread tension device.

The spring retainer 33 has a dial shaft 35.
The thread tension dial 37 rotatably attached to the thread tension plate 17 is engaged with. The presser bar 39 is attached to the sewing machine body so as to be slidable in the axial direction, and a cloth presser 41 is attached below. A presser bar holder 43 is fixed to the presser bar 39, and a cam of a presser lever 45 engages with the end thereof. The lifting lever 4
5 is rotatably attached to the sewing machine body by a lever shaft 47.

The thread loosening lever 49 is rotatably attached to the sewing machine main body by a shaft 51, and is pressed against the cam surface of the pressing lever 45 by a spring 53.
The other of the springs 53 is attached to the sewing machine main body. The other end of the thread loosening lever 49 has a bifurcated shape, and a part of the dish opening lever 29 is inserted and engaged therein.

Next, the operation of this embodiment will be described. When the main shaft 1 is rotated to move the needle tip above the upper surface of the needle plate, the operation cam 3 fixed to the main shaft 1 is rotated and the pin 9 is engaged with 3a of the operation cam 3. Further, when the press-up lever 45 is rotated, the cloth presser 41 moves up and the bifurcated end of the thread loosening lever 49 moves to the left. A part of the plate opening lever 29 engaged with the bifurcated end also moves to the left,
The tension discs 21 and 23 are opened by the lever principle. Further, the tip of the plate opening lever 29 on the opening lever 7 side is pressed and held by the cam portion of the opening claw 13 to prevent it from returning to the right. Therefore, the opening claw 13 corresponds to a holding means. . It returns to the right when the needle hole (not shown) is below the upper surface of the needle plate, the pin 9 engages with 3b of the actuating cam 3, and the opening claw 13 and the plate attached to the opening lever 7 are inserted. The release lever 29 holds the lifting lever 45.
It is when it does not touch even if it moves to the left or right.

Therefore, in the thread tension regulator releasing device of the sewing machine of the present embodiment, when thread is threaded, the main shaft 1 is rotated by taking in and out of the cloth to bring the needle tip above the needle plate, and the presser lever 45 is moved. Once raised, the thread tension discs 21 and 23 are held in the open and inactive state even when the presser lever 45 is lowered, and the main shaft 1 rotates until the needle hole moves under the needle plate until the needle hole moves. Since the tone plates 21 and 23 are held in the inoperative state, the operator neglects to raise the lifting lever 45,
Even with the presser lever 45 lowered, the thread tensions 21 and 21
No. 3 is held in an inactive state, and the thread is reliably inserted between the thread tension discs 21 and 23 even when the upper thread is hooked.
The thread can be reliably hooked.

[0014]

As is apparent from the above description, the thread tension regulator releasing device of the sewing machine of the present invention, when the thread is hooked, once the press-up lever is raised to take in and out the cloth,
Even if the operator accidentally lowers the hold-up lever, the thread tensioner remains inactive because the thread tensioner is held in the inactive state even if the hold-up lever is lowered. Even when the upper thread is hooked, the thread is surely inserted into the thread tension tray, so that the thread can be hooked reliably.

[Brief description of drawings]

FIG. 1 is a top view showing the configuration of the present embodiment.

FIG. 2 is a front view showing the configuration of the present embodiment.

FIG. 3 is a top view showing a state in which a press-up lever of this embodiment is raised.

FIG. 4 is a front view showing a state in which a press-up lever of this embodiment is raised.

FIG. 5 is a side view showing the configuration of an actuating cam according to this embodiment.

[Explanation of symbols]

 1 Spindle 3 Actuating Cam 5 Release Lever Shaft 7 Release Lever 9 Pin 13 Opening Claw 21 Thread Tray Disc 23 Thread Tray Disc 29 Disc Release Lever 45 Presser Lifting Lever 49 Thread Loosening Lever

Claims (1)

[Claims] 1. A sewing machine in which a thread tension device is switched to an inactive state by raising a presser-up lever in order to operate the thread tension device in the inactive and inactive states in synchronization with a main shaft. The thread tension regulator releasing device, comprising: an actuating cam having two positions, and holding means that is actuated by the actuating cam to hold the thread tensioner in an inactive state.