JPS608859Y2 - sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sewing machine, and more particularly to a phase adjustment means for a rotary balance of a sewing machine.

In order to form perfect stitches, the phase of the thread take-up with respect to the hook must be appropriate, and there is a conventional sewing machine equipped with a rotary thread take-up, as disclosed in Japanese Patent Publication No. 26-5533.

In this device, one end of a curved handle nail 25 is fixed to the needle bar operating curved handle 16, one end of a chain rod 24-band chain rod 39 at the other end of the curved handle nail is rotatably inserted, and the other end of the chain rod 39 is inserted. ,
A bearing pin 38 is rotatably inserted, and a short arm 37 is fixed to the bearing pin, one end of which is provided with a split date grain 36, into which one end of a short shaft 33 is inserted, and a short arm 37 is attached to the other end. Since the arm 34 is fixed and the mounting part 35 is fixed to the tip thereof, the number of parts is complicated, the cost is high, and it is difficult to ensure the accuracy of the assembly dimensions, so vibration and noise are likely to occur.
Moreover, there was a great need for oil supply to the shaft.

The purpose of this invention is to separate the disc to which the thread take-up is attached and the crank pin so that the timing of lifting the thread take-up can be easily adjusted in order to form a perfect seam even when the type of thread changes. The purpose is to connect both parts and provide a sewing machine that does not have the problems of conventional sewing machines.

An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIGS. 1 and 2, an upper shaft 13 is rotatably supported by a bearing 12 in an arm 11 of a sewing machine 10. As shown in FIGS.

The left end of the upper shaft 13 is fixed to a crank 14, and the crank 14 has a shaft portion 15a at one end, a split tightening groove 15b at the other end, and a through hole 15c parallel to the shaft portion 15a. The crank pin 15 is also fixed to the crank 14, with the shaft portion 15a rotatably supporting a bearing portion 16a of the needle bar crank rod 16.

The lower bearing portion 16b of the needle bar crank pin 16 is connected to the needle bar 1
A needle bar holder 18 connected to 7 is loosely fitted.

On the other hand, in the other end through hole 15C of the crank pin 15, a balance mounting member 19 is fixed to the flange part 19a so that the single plate rotary balance 22 is directed outward from the arm.
A shaft portion 20 protruding from the center of the crank pin 9a is fitted into the through hole 15c of the crank pin 15 concentrically with the upper shaft 13 and fixed by being split and tightened with a tightening screw 21.

As described above, in the present invention, the crank is fixed to the upper shaft, the crank pin is rotatably fitted to the crank, and the disk with the balance attached to the crank pin can be adjusted and fixed. The single-plate rotary balance can be adjusted in phase with respect to the upper shaft along with the balance mounting member, making it easy to fine-tune the timing of lifting the balance to form a perfect seam.Moreover, since there are few components, there is no timing shift. There is almost no noise, and noise and vibration are also reduced, which is a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of an embodiment of a sewing machine according to the present invention;
FIG. 2 is a view taken in the direction of arrow A in FIG. 1. 13... Upper shaft, 14... Crank, 1
5...Curved crank pin, 15c...Through hole, 1
9... Balance mounting member, 19a... Flange portion, 20... Shaft portion, 22... Single plate rotating balance.

Claims (1)

[Scope of utility model registration request] In a sewing machine having a single-plate rotary take-up that rotates concentrically with the upper shaft via a crank pin by a crank fixed to the end of the upper shaft, a flange portion to which the single-plate rotary take-up is fixed and a A sewing machine comprising: a thread take-up mounting member having a shaft portion protruding from the center of a flange portion; and a crank pin having a through hole into which the shaft portion is fitted and screwed concentrically with the upper shaft.