JPS6245656Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to an upper feed dog movement mechanism for a sewing machine in which the feed dog and the upper feed dog cooperate to nip and feed the workpiece.

[Prior art]

As an upper feed mechanism of this type of sewing machine, the one shown in FIG. 1 has been proposed. That is, it consists of links 2, 3, 4, and 5 connected to an upper feed shaft 1 rotatably supported in parallel with the main shaft via an eccentric cam fixed to the main shaft (not shown), and an upper feed dog provided on the oscillator 6. 7 and links 10, 11, 1 connected to an eccentric cam 9 fixed to the main shaft 8.
2 and 13, the L-shaped lifting link 14 is rotated about the shaft 16 of the support body 15, and the upper feed dog 7 provided on the swinging body 6 moves up and down. The upper feed dog 7 rises and moves to the right, and descends to feed the workpiece to the left in cooperation with a feed dog (not shown). Further, the work to be sewn is taken in and out by vertically moving the upper feed dog 7 and the presser foot 17. The oscillating body 6 includes a coil spring 19 inside the hollow of the presser bar 18 supported by the support body 15.
It is constantly pressed downward via the secondary presser bar 20 and the sphere 21 due to the elastic force of the presser bar 20 and the sphere 21. However, in the upper feed mechanism, the upper feed tooth 7 and the receiving member 6a are provided on the oscillating body 6, and the receiving member 6a rises against the elastic force of the coil spring 19 due to the rotation of the elevating link 14. It is configured so that it is pressed down by an elastic force and lowered, and in time with this, the upper feed dog 7 horizontally reciprocates to perform four movements. Therefore, when the rocking body 6 horizontally reciprocates in the cloth feeding direction, the above-mentioned receiving member 6a moves between the sphere 21 and the roller 14a of the lifting link 14.
It slides in the direction of the arrow while receiving the elastic force of the coil spring 19 between.

Therefore, the receiving member 6a, the sphere 21, and the roller 14a
Wear occurs in the parts between the parts, which induces backlash (structural play).

As a result, the amount of rise of the upper feed dog 7 decreases, causing clogging at the step part of the workpiece, and the pressing force of the workpiece decreases, causing sagging, which deteriorates the sewing quality. There were some maintenance and quality defects.

[Purpose of invention]

This invention aims to solve the above-mentioned conventional drawbacks in a simple manner.

[Structure and action of the device]

Identical structures (corresponding) are indicated by the same reference numerals, and an embodiment of this invention will be described below with reference to the drawings.
and b and c are front and side views (left and right),
FIG. 3 is a perspective view. 18 is a presser bar;
A sub presser bar 20 is loosely fitted into the lower part of the hollow interior, and a screw 22 is screwed in so as to sandwich the coil spring 19 in the upper part and press it downward from above. Further, the support body 15 is fixed to the lower end of the presser bar 18. The support body 15 includes a presser foot 17 (not shown) having a hole through which the needle passes vertically, and an arm portion 15c that is formed to hang down and has horizontal shaft holes 15a and 15b perpendicular to the cloth feeding direction at the front end in the cloth feeding direction. will be established. Reference numeral 6 denotes a rocking body, which includes a receiving member 6a having a horizontal surface that extends horizontally so as to engage with the sub-presser bar 20 via a sphere 21, and a receiving member 6a that is perpendicular to the cloth feeding direction at the forward end in the cloth feeding direction. A base portion 6d having a shaft hole 6b and a fitting groove 6c extending along the cloth feeding direction is provided. Reference numeral 23 indicates an upper feed presser foot, and a connecting portion 23a having a horizontal screw hole orthogonal to the cloth feeding direction at one end thereof.
and the mounting bracket 23b of the upper feed dog 7 along the cloth feeding direction at the other end, and the connecting portion 23a and the mounting bracket 23.
A long hole portion 23c is provided between the hole portion 23b and the hole portion 23c. Now, the second
In the figure, arm portions 15 of the support body 15 are formed to hang down.
Loosely insert the base 6d of the oscillator 6 into the space between
to loosely fit.

The support shaft 24 is passed through the shaft holes 15b, 6b, and the elongated hole portion 23c of the support body 15, the swinging body 6, and the upper feed presser foot 23, and the other end of the support shaft is connected to the arm portion 15c of the support body 15. Lock with a retaining ring on one side of the outside surface.

By doing this, the upper feed presser foot 23 is
It becomes possible to reciprocate and slide in the horizontal direction within the fitting groove 6c of the rocking body 6 through the elongated hole 23c with respect to the support shaft 24.

Furthermore, to describe the structure of the support body 15, 1
5d is a mounting portion of the presser foot 17 (not shown);
15e is a mounting hole for the presser bar 18. When the presser bar 18 is loosely inserted into the mounting hole 15e and fixed with the screw 25, the result will be as shown in FIG. 1a.

On the other hand, the L-shaped lifting link 14 has an arm portion 14b.
An arm portion 14c having a roller 14a at the tip thereof and a shaft hole 14d in the intermediate portion are provided.

The arm 14c of the lift link 14 is inserted into the space 6e (see FIG. 2) of the swinging body 6 from the inside of the arm 15c of the support 15, and the arm 14c is supported by the lower surface of the receiving member 6a.
Next, the support shaft 26 is inserted through the shaft hole 15a of the support 15 and the shaft hole 14d of the lift ring 14,
The other end of the support shaft is engaged with a stop ring on one side of the outer surface of the arm portion 15c of the support 15.
One end of b is connected to the second interlocking means (links 10, 11, 12,
13) is rotatably connected to the link 10.

On the other hand, the connecting portion 23a of the upper feed presser foot 23 is connected to the upper feed shaft 27, which is swingably supported parallel to the main shaft via an eccentric cam fixed to the main shaft. 29, a swinging link 31, a swinging link 32 which swings around a swinging shaft supported on a machine frame 30 (not shown) is attached with a step screw 33 together with the link 32.

This invention has the above configuration, and the functions thereof will be explained next. In Fig. 2a, the upper feed shaft 2
7 rotates clockwise, the swing link 31 rotates counterclockwise through the rod 28 and the connecting portion 29 around a swing shaft (not shown), and the link 32 rotates clockwise. The upper feed presser foot 23 slides in the fitting groove 6c of the rocking body 6 and moves to the right.

Eccentric cam 9 fixed to main shaft 8 in synchronization with this
When the link 14 connected to moves downward, the link 12 rotates clockwise, and the elevating link 14 rotates counterclockwise about the shaft 26 via the link 26. Therefore, the arm portion 14 of the elevating link 14
Since the ring 14a of c presses the lower surface of the receiving member 6a of the oscillator 6 against the elastic force of the coil spring 19, the upper feed dog 7 is moved upwardly away from the workpiece while the upper feed presser foot 23 is pressed. slides within the fitting groove 6c of the rocking body 6 and moves to the right.

Further, when the upper feed shaft 27 rotates counterclockwise, the swing link 31 rotates clockwise about the swing shaft (not shown) via the rod 28 and the connecting portion 29, and the link 32 rotates counterclockwise. Since it rotates in the direction, the upper feed presser foot 23 swings within the fitting groove 6c of the swinging body 6 and moves to the left.

Eccentric cam 9 fixed to main shaft 8 in synchronization with this
When the link 14 connected to moves upward, the link 12 rotates counterclockwise, and the elevating link 14 rotates clockwise about the shaft 26 via the link 6. Therefore, the ring 14a of the arm portion 14c of the elevating link 14 is separated downward from the lower surface of the receiving member 6a of the oscillator 6, so that the upper feed dog 7 is connected to the coil spring 1.
The upper feed presser foot 23 slides within the fitting groove 6c of the rocking body 6 and moves to the left while being pressed against the workpiece by the elastic force of the upper feed dog 7, and thus the upper feed dog 7 performs four movements. The horizontal distance of the upper feed dog 7 changes in proportion to the swing angle of the upper feed shaft 27, and the force of the upper feed dog 7 to press the workpiece is applied by tightening the screw 22 and coiling By compressing the spring 19 it becomes stronger.

In addition, the first moving means 28 in the above embodiment,
29, 31, and 32 are configured to extend from the inside of the machine frame 30, but a structure in which this first moving means is configured to extend from the outside of the machine frame 30 also has similar effects. Furthermore, in the above embodiment, as shown in FIG.
The same effect can be obtained even if the structure in which the cylindrical or cylindrical upper feed presser foot 23 is slidable in the cylindrical fitting hole 6c of the rocking body 6 is changed from the structure in which it is slidable in the fitting groove 6c. effective.

[Effect of idea]

As described above, this invention rotatably supports the base of the oscillator 6 and the elongated hole 23c of the upper feed presser 23 with respect to the support 15 by the support shaft 24, and The horizontal reciprocating motion by means of the rocking body 6
The upper feed presser foot 23 slides back and forth in the fitting groove or fitting hole 6c provided in the
Since the structure is such that the upper feed dog 7 is moved four times by the operation of The elastic force of the coil spring 19 is only received between the two ends. Therefore, the receiving member 6a
Since there is no sliding friction between the sphere 21 and the roller 14a, the wear of each member is extremely reduced, and there is no occurrence of backlash. As a result, clogging and sagging in the stepped portions of the sewing material are eliminated, and there is an excellent practical effect in improving the durability of the sewing machine, safety in maintenance, and sewing quality.

[Brief explanation of the drawing]

Figures 1a and b are front views and partial sectional views showing the prior art mechanism, Figures 2a and b, c
3 is a front view and a side view (left and right) showing an embodiment of the upper feed dog movement mechanism of the present invention, and FIG. 3 is a perspective view showing the main part of the present invention.

Claims (1)

[Claims for Utility Model Registration] Presser bar 18 supported on machine frame 30 in a vertically movable manner
, a support body 15 supported at the lower end of the presser bar 18 and equipped with a presser foot 17, and a receiving member 6a extending along the cloth feeding direction and having a fitting groove or fitting hole 6c and a flat surface. A rocking body 6 whose base part is rotatably supported with respect to a support body and whose receiving member 6a always receives a downward force.
and an upper feed presser foot 23 whose connecting portion 23a that supports the upper feed dog 7 and extends forward in the cloth feeding direction and whose central portion is slidable in the fitting groove or fitting hole 6c of the rocking body 6;
An elevating link 14 whose center portion is rotatably supported on a support body 15 and whose one end extends below the receiving member 6a of the rocking body 6, and an upper feed presser foot 23 that is interlocked with the main shaft.
a first moving means for horizontally sliding within the fitting groove or fitting hole 6c of the oscillating body 6, and a lifting link 14 connected to the receiving member 6a of the oscillating body 6 in conjunction with the main shaft. and a second interlocking means for providing vertical movement, and the upper feed dog 7 is provided with a second interlocking means interlocking with the main shaft.
An upper feed dog movement mechanism for a sewing machine, characterized in that the upper feed dog 7 is moved up and down by a second interlocking means while reciprocating in the cloth feeding direction.