JPS6226063Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a top feed mechanism in a top and bottom feed sewing machine.

[Prior art]

An example of a top feed mechanism in a conventional top feed sewing machine is the one shown in FIG. 1, which was published by the applicant in 1982-26795.

To summarize the structure, numeral 1 denotes a rocking body having an upper arm 1a and a lower arm 1b, and is rotatably supported on a shaft 3 fixed to a machine frame 2 of the sewing machine.
Although the lower feed dog 4 is not shown in the oscillator 1, the upper arm 1a is connected to a connecting link 5 which is linked to the horizontal feed element of which four cloth feed movements are performed by a horizontal feed element and a vertical feed element. Perform constant oscillation.

Reference numeral 6 denotes an upper feed arm whose base is rotatably connected to the lower arm 1b by a connecting shaft 7, and an upper feed dog 8 facing above the lower feed dog 4 is fixed to the tip, and the machine frame 2 A presser spring 10 held by an adjustment knob 9 screwed into the upper feed dog 8 is biased via a presser roller 12 of a presser shaft 11 to press the upper feed dog 8 downward.

Reference numeral 13 denotes a female drive shaft as an upper feed vertical mechanism, which includes a vertical moving arm 13a equipped with a vertical moving roller 15 that comes into contact with the lower surface of the tip of a leaf spring 14 fixed to the lower surface of the upper feed arm 6 with a small screw, and an upper feed vertical mechanism. It is integrally formed with a knife arm 13b that extends beyond the tooth 8 and has a cloth cutting knife 16 fixed thereto, and when the lower feed dog 4 rises in synchronization with the main shaft of the sewing machine (not shown) to feed the cloth, the arrow It rotates in the direction of arrow A, and when the cloth feeding is completed and descends, it rotates in the direction of arrow B. In addition, the upper feed arm 6
A shock absorber 1 made of elastic synthetic resin or the like is placed on the lower surface of the
7 is attached.

However, in such a conventional upper feed mechanism, the fulcrum of the upper feed dog movement is the connecting shaft of the lower arm 16 of the oscillator 1, so the fulcrum of the vertical movement of the upper feed arm is far away from the presser shaft 11. Moreover, since the center of gravity is at the tip, the presser shaft 11 and the presser spring 10 are constantly moved with a large stroke in the vertical direction due to the movement of the upper feed dog, and the upper feed is caused by the surging (cracking vibration) of the presser spring. There are problems in that tooth jumping occurs, which causes a decrease in cloth feeding force, which has an adverse effect on seam formation, and also causes noise generation.

[Purpose of invention]

This invention was made in view of these problems, and by configuring the fulcrum of the vertical movement of the upper feed arm at the contact area of the presser foot shaft, which is near the center of the upper feed arm, The purpose is to solve this problem.

〔Example〕

An embodiment of this invention will be described below with reference to FIG. Note that the same members as in the conventional example are designated by the same reference numerals, and their explanations will be omitted.

First, I will explain the configuration.

The upper feeding arm 26 is connected to a central portion 26C in which a long hole 26n is formed in the longitudinal direction, and a base portion 2 formed below.
A downward U-shaped notch 26s is carved on the end of 6B for horizontal movement, and a U-shaped notch 26j is carved on the side surface of the tip side for vertical movement,
On the other hand, an upper feed dog 8 is fixed to a tip portion 26A extending diagonally upward from the center portion 26C.

Further, the upper feed arm 26 is supported by the presser roller 32 of the presser shaft 31 at the elongated hole 26n.
A horizontal moving roller 1 is provided on a connecting shaft 7 protruding from the lower arm 1b of the rocking body 1 in the notch 26s of the base 26B.
C is fitted so as to be interlocked with the rocking body 1.

Further, the knife drive shaft 33, which swings in synchronization with the main shaft of the sewing machine, has the cloth cutting knife 16 fixed to its tip extending obliquely upward. An L-shaped link 35 is rotatably supported on a shaft 34 fixed to the machine frame 2, and a vertically movable roller 35C provided at the tip of one arm 35a fits into the notch 26j of the base 26B. The upper feed arm 26 is interlocked with the L-shaped link 35. Further, the other arm 35b of the link 35 and the knife drive shaft 33 are connected by a link 36 rotatably engaged with protruding pins 35p and 33p, respectively.

Next, the effect will be described.

In Figure 2, the upper and lower feed dogs 8 and 4 are used to
The figure shows the state where the cloth feed is completed by pinching the cloth and moving it forward (to the left in the figure). The knife drive shaft 33 completes its rotation in the direction of arrow A, and also completes the rotation of the L-shaped link 35 in the direction of arrow B, so that the arm 35
Since the notch 26j for vertical movement is fully pushed up by the vertical movement roller 35C, the upper feed arm 2
6 swings in the direction of arrow B using the presser roller 32 as a fulcrum, and is urged downward by the pressing force of the presser spring 10 via the roller 32 and the elongated hole 26, so that the upper feed dog 8 The fabric to be sewn N is pressed.

Note that when the workpiece N is fed by entering the lower part of the upper feed dog 8, the stepped end surface 3 of the presser foot shaft 31
1d and the machine frame hole step end surface 2d, the presser spring 10 rebounds and the upper feed arm 26
The upper feed dog 8 presses the cloth N to be sewn, but after the cloth N has passed, the tension of the pressing spring 10 returns to the original state with no gap S.

Synchronizing with the timing when the lower feed dog 4 starts to descend from the state shown in FIG. 35 begins to rotate in the direction of arrow A, and the vertically moving roller 35C moves toward the base 26 of the upper feed arm 26.
B is pulled down by the notch 26j for vertical movement, so the upper feed dog 8 uses the presser roller 12 as a fulcrum.
It rises away from the upper surface of the cloth N to be sewn, and at the same time the lower feed dog 4 also descends and leaves the cloth N to be sewn.

In this state, when the rocking body 1 rotates in the direction of arrow A around the shaft 3 in conjunction with the horizontal feed element,
The horizontal moving roller 1c of the lower arm 1b of the upper feed arm 26 is
Since the upper feed arm 26 is moved backward (to the right in the figure) by pushing the notch 26s for horizontal movement, the upper feed arm 26 moves backward while rolling the holding roller 32 in the elongated hole 26n, and the upper feed tooth Move position 8 to the rear.
In synchronization with this, the lower feed dog 4 also moves rearward.

Next, in synchronization with the timing when the lower feed dog 4 starts to rise, the swinging direction of the knife drive shaft 33 is changed to the direction of arrow A and starts swinging. Therefore, vertical moving roller 35C
begins to rotate in the direction of arrow B, and in order to raise the base portion 26B, the upper feed arm 26 swings in the direction of arrow B and lowers the upper feed dog 8, so that the upper feed dog 8
The cloth N is stopped at the position where it abuts, and the cloth N is held between the upper and lower feed dogs 8 and 4.

Subsequently, the rocking body 1 rotates in the direction of arrow B and the horizontally moving roller 1c advances the upper feed arm 26 along the elongated hole 26n to the original position, and the state returns to the state shown in FIG. 2.

By repeating the above operations, the cloth is fed one after another.

In addition, as another embodiment, the center portion 46C of the upper feed arm 46 is formed into a linear shape with a constant width, and the center portion 46C
The base of the swinging arm 48, which rotatably supports the guide member 47 that slidably holds the guide member 6C at its tip, is connected to the machine frame 2.
The guide member 47 is rotatably provided on the shaft 1.
1, and the other parts are substantially the same as those in the above embodiment, so that similar actions and effects can be obtained.

[Effect of idea]

As explained above, in this invention, a long hole is bored along the longitudinal direction of the upper feed arm so that the central part serves as a fulcrum for swinging, and a presser roller provided on the presser shaft is fitted into the upper feed arm. In addition, U-shaped notches are carved in the base of the upper feed arm for horizontal movement and for vertical movement, respectively, and a swinging body linked to the horizontal feed element and a female drive shaft linked to the vertical feed element are connected. are associated with the above-mentioned notches, so that the four movements for cloth feeding are performed, and while the upper feed dog is making the four movements, no deflection occurs in the pressing spring. There is no surging, making it easier to run the sewing machine at higher speeds, reducing noise, and because the stepped end of the machine frame hole, which acts as a stopper when the presser foot shaft moves, is located inside the machine frame, impact noise is less likely to be transmitted to the outside.

[Brief explanation of the drawing]

Figure 1 is a side view of the upper feed mechanism of a conventional sewing machine, Figure 2 is a side view of the upper feed mechanism of one embodiment of this invention, and Figure 3 is a side view of main parts of another embodiment. be. 1... Rocking body, 26, 46... Upper feed arm, 26
B...base, 26C, 46C...center, 26s
...Notch, 26j...Notch, 31,11...
Presser arm, 35... L-shaped link, 36... link.

Claims (1)

[Scope of utility model registration request] The center part of the upper feed arm is used as a fulcrum for pressing pressure and swinging, and is pressed down by the presser foot shaft, and the notch for horizontal movement and notch for vertical movement carved in the base.
A configuration in which the upper feed arm performs the four movements for cloth feeding by operating the rocking body linked to the horizontal feed element and the knife drive shaft linked to the vertical feed element through links and L-shaped links, respectively. An upper feed mechanism of a sewing machine characterized by the following.