JPS606675B2 - Cloth feed mechanism of sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a feed mechanism for a sewing machine that performs a predetermined feed movement while keeping the upper surface of a feed dog always horizontal.

As shown in FIG. 1, in the conventional feeding mechanism, when a shaft 1 is rotationally driven, a feed table support 3 whose forked portion is iron-coupled to a cam body 2 which is provided eccentrically to the shaft 1 is moved upward and downward. move downwards,
This causes the feed dog 5 to move upward and downward, and
The movement in the longitudinal direction is performed by a cam body (not shown) provided eccentrically on the shaft 1 and a link (not shown) connecting this cam body to the feed bar support 3.

By combining these upward and downward movements and the above-mentioned directional movements, the feed dog 5 can perform an elliptical movement and feed the cloth in a predetermined direction. However, since the rear part of the feed bar support 3 is swingably supported by the fixed shaft 7 via the link 6, when the front part of the feed bar support 3 moves up and down by the cam body 2 and moves back and forth, the needle is moved. A state in which the cloth is fed occurs when the angle formed by the surface of the plate 8 and the upper surface of the feed dog 5 is an inclination angle of Q.

The fabric is fed by the pressing force of the presser foot (not shown) and the movement of the feed dog 5, but in the above state, the part of the fabric below the presser foot where the fabric is fed by the feed dog 5 and the presser foot. This has the disadvantage that there are parts that are not being fed, which causes the fabric to shrink and the seams to be unsightly.

Furthermore, since the time for feeding the cloth over the entire surface of the feed dog 5 is shortened, the feeding force becomes weak, the straightness of the feed deteriorates, and the stitches tend to bend.

Furthermore, when the feed dog 5 is raised, only the tip comes into contact with the cloth at first, so there is a drawback that the cloth is likely to be scratched. Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 3, reference numeral 10 denotes a drive shaft rotatably supported on the machine frame below the pet surface (not shown), which rotates in conjunction with a motor (not shown). A shaft 11 is swingably supported on the machine frame in parallel with the drive shaft 10, and is connected to the drive shaft 10 via a swing mechanism (not shown) to swing; a shaft 13 has its base end fixed to the shaft 11; This is a link mechanism consisting of a swinging link 13A and a connecting link 13B supported at the end of the swinging link 13A so as to be extendable.

Reference numeral 14 denotes a feed base for main feeding, one end of which is rotatably connected to the connecting link 13B of the link mechanism 13 so as to be able to move up and down by the swinging of the shaft 11, and a forked portion 14A formed at the other end; It has a feed dog 15 on its upper part.

Reference numeral 16 denotes an up/down feed mechanism that moves the other end of the feed table 14 up and down in conjunction with the drive shaft 10. In this embodiment, a cylindrical eccentric cam 6a is provided eccentrically from the axis of the drive shaft 1. is used.

The forked portion 14A is iron-fitted to the eccentric cam 16a and engaged with the eccentric cam 16a via the square piece 17. Reference numeral 18 denotes a back-and-forth feeding mechanism consisting of a swinging village 18A connected to the eccentric cam 25A and whose end is rotatably supported by a pin 19 provided on the feed base 14. rotates, thereby causing the swinging punch 18A to reciprocate back and forth, thereby moving the feed table 14 back and forth.

20 is a link mechanism consisting of the swing link 13A with one end fixed to the pith 11 and a connecting link 21 rotatably supported on the other end of the swing link 13A;

This is a feed stand for sub-feed that is movably downwardly connected to the connecting link 21 of the link mechanism 20 so as to be reversible, and has a forked portion 22A formed at the end of the pond, and has a feed dog 23 on its upper part. Reference numeral 16 denotes an up/down feed mechanism that is moved by the drive shaft 10 and moves up and down the end of the feed table 22, and shares the same eccentric cam 16a as described above.

The forked portion 22A is engaged with the eccentric cam 16a via a square piece 17 which is iron-coupled to the eccentric force ram 16a.

25 is a cylindrical eccentric cam 25A provided eccentrically with respect to the axis 0 of the drive shaft 10, and an armature 25 having one end iron-coupled to the eccentric cam 25A.
A front-rear feed mechanism that moves the feed table 22 forward and backward in conjunction with B;
26 is a section before connecting the forward/backward feed mechanism 25 and the feed base 22;
Using the rear feed adjustment device, adjust the mounting position within the long hole 26a formed along the arc of the fan-shaped swing bar 26A rotatably supported at the other end of the arm village 25B and the swing lever 26A. The connecting punch 26B has one end rotatably supported on a pin 26b provided on the sub-feed table 22, and the other end rotatably supported on a pin 22b provided on the sub-feed table 22.

Next, for convenience, the operation of this embodiment will be explained separately for the feeding device and the play feeding device.

{i) Regarding the operation of the feed device for king feed, when the sewing machine is driven, the drive shaft 10 rotates.

When the biased cam 16a serving as the upper/lower feed mechanism 16 rotates within the forked portion 14A of the feed table 14, the feed table 14
The front part of the feed dog 15 is given a reciprocating upward and downward movement.
Give a predetermined upper/lower interlock to the .

Further, when the shaft 11 swings due to the rotation of the drive shaft 10, the swing of the pith 11 gives a predetermined reciprocating up and down movement to the rear part of the feed table 14 via the swing link 13A and the connecting link 13B. In front of these feed tables 14. Since the upward and downward movements of the rear part are synchronized, the front and rear parts of the feed table 14 move upward and downward without being tilted uniformly, and therefore the feed dog 15 provided on the feed table 14 also does not tilt. Move up and down. Next, the movement in the forward and backward directions is caused by the rotation of the eccentric cam 25A, which causes the connecting link 21 to move back and forth in a reciprocating manner, and thereby the feed table 14 also moves forward and backward in a reciprocating manner, thereby moving the feed dog 15 forward.

Exercise afterwards. 'o} Regarding the action of the sub-feeding feed device, when the sewing machine is driven, the drive shaft 10 rotates.

As a result, the eccentric cam 16 as the upper/lower feed mechanism 16
a rotates within the forked portion 22A of the feed table 22.

Then, reciprocating upward and downward movements are applied to the front part of the feed table 22, and accordingly, predetermined upward and downward movements are applied to the feed dog 23. Further, when the shaft 11 swings due to the rotation of the drive shaft 10, the shaft 11
The swing gives a predetermined reciprocating up and down movement to the rear part of the feed table 22 via the swing link 13A and the connecting link 21.

Since the vertical and downward movements of the front and rear parts of the feed table 22 are synchronized with each other, the front and rear parts of the feed table 22 can move up and down without being tilted uniformly. tooth 23
It also moves up and down without tilting. Further, as the shaft 11 swings, the swing lever 26A connected to the shaft 11 via the swing link 13A also moves up and down in synchronization with the regular feed table 19.

Next, the movement in the front and back direction is caused by the rotation of the eccentric cam 25A, which causes the arm 26B to reciprocate back and forth, thereby causing the swing lever 2
6A swings around the pin 13a of the swing link 13A.

The connecting village 26 is connected to the pin 26b attached to the elongated hole 26a of the swinging lever 26A by swinging the swinging lever 26A.
B is moved back and forth in a reciprocating manner, and thereby the feed table 22 and the feed dog 23 are also moved back and forth. In this way, the swing lever 26A and the connecting village 26B as adjustment devices are simply connected to the feed base 22.
In addition to imparting back and forth motion to the feed bar 22, it also moves itself up and down as the feed bar 22 moves up and down, so the connecting village 26B does not rotate around the pin 26b when the feed bar 22 moves in an elliptical motion. It disappears.

Therefore, the connecting village 26B does not affect the amount of forward and backward movement of the feed table 22, and performs normal elliptical movement as shown in FIG. 2A. Note that the forward and backward feed amount of the feed dog 23 can be changed by changing the attachment position of the pin 26b to the long piece L26a.

As described above, according to this invention, the feed dog can always remain parallel to the throat plate surface regardless of the upper or lower position, so the cloth is always fed using the entire surface of the feed dog, which prevents the cloth from shrinking. The seams no longer become unsightly, and beautiful seams can be formed.

In addition, the feeding force is strong, the straightness of the feeding is improved, and straight stitches can be formed, and the fabric is not scratched by the feeding teeth.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of a conventional feeding device, Fig. 2 is an explanatory diagram showing the locus of the feed dog of the feed device of the present invention and the trajectory of the conventional feed dog, and Fig. 3 is an explanatory diagram showing the locus of the feed dog of the feed device of the present invention. FIG. 4 is a partial sectional view of the feeding device for sub-feeding,
FIG. 5 is a perspective view of a differential feeding device including a feeding device of the present invention and a feeding device for sub-feeding. 10... Drive shaft, 11... Axis, 13... Link mechanism, 16... Upper/lower feed mechanism, 14...
...Feed table, 18... Front/rear feed mechanism. O figure O figure O figure 2 spear figure 3 figure soup 4 figure spear figure

Claims (1)

[Claims] 1 A drive shaft that is rotatably supported on the machine frame and rotates in conjunction with the motor; A shaft that is supported on the machine frame parallel to the drive shaft 10 and swings in conjunction with the drive shaft; A link mechanism consisting of a swinging link whose base end is fixed to a shaft so as to swing, and a connecting link 13B whose lower end is rotatably supported by the swinging link so as to swing back and forth, and interlocked with a drive shaft. Equipped with an up/down feed mechanism that can move up and down, and a feed dog.
The feed bar 14 has one end rotatably supported by a connecting link and the other end is linked to the upper/lower feed mechanism 16, and the other end is loosely fitted to the eccentric cam 25A fixed to the drive shaft 10, A cloth feeding mechanism of a sewing machine in which a back and forth feeding mechanism 18 is rotatably connected to a fabric feeding mechanism 14;