JPS62155893A - Needle rod shaking arm holder of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention The present invention relates to a needle bar swinging arm holding device for a sewing machine, in which the needle bar swings. The mounting of the needle bar swing arm in a moving sewing machine is utilized as a means.

(Prior Art) Conventionally, in this type of device, at the upper end of the needle bar swinging arm,
A shaft hole is drilled perpendicular to the direction of the swinging motion, and a holding shaft is loosely fitted into this shaft hole, and the swinging arm is prevented from moving in the axial direction at a fixed position by two retaining rings on the holding shaft. It was done. The holding shaft was fixed to a hole drilled in the arm so that its mounting position in the axial direction could be adjusted, and rotatably held the needle bar swinging arm.

(Problem to be solved by the invention) However, in the above conventional device, there is a
Drilling a holding shaft mounting hole perpendicular to the movement direction of the needle bar swing arm,
Screw hole machining was required, which increased machining equipment, machining costs, etc.

The same increase in cost applies to the provision of a holding shaft hole in the upper part of the needle bar swinging arm.

Furthermore, due to the structure of the device, the number of assembly steps increases overall, and the cost burden becomes high, which is a disadvantage that cannot be avoided.

The present invention aims to develop a needle bar swinging arm that can be expected to alleviate or reduce the degree of the above-mentioned defects.

[Structure of the invention]

(Means for Solving the Problems) In the present invention, as a means for solving the above-mentioned problems, the use of a holding shaft, which is a means for connecting the arm and the needle bar swinging arm, which was conventionally used, is abolished. Both the arm and the swinging arm were provided with spherical surfaces with concave and convex surfaces (or vice versa), and these were brought into surface pressure contact to connect the two. That is, (1) A convex hemispherical mounting portion was formed integrally with the arm at the upper part of the face plate side of the sewing machine arm.

(2) The upper end of the needle bar swinging arm has a four-hemisphere shape on the negative side having the same diameter as the spherical diameter of the convex hemisphere attachment part of the arm, and a convex hemisphere on the other side having a radius around the center of this four-hemisphere. It was molded in one piece to form a shape.

(3) An elastic presser plate is provided which has a concave hemisphere having the same diameter as the convex hemisphere on the other side of the needle bar swinging arm.

(4) The presser plate pressed against the surface joint of the uneven hemispherical surface of the arm and the needle bar swinging arm.

(Function) The needle bar swinging arm is rotatable with respect to the arm at the spherical surface joint, and the center points of the spherical surfaces of each champion, including the elastic presser foot slope, tend to be aligned with the - line.

(Embodiment) In FIG. 1, 1 is a sewing machine arm, and 2 is a needle bar swing arm. Reference numeral 1a denotes a convex hemispherical attachment portion formed integrally with arm 1, and 2a (FIG. 3) denotes an attachment portion formed at the upper end of needle bar swing arm 2. This attachment part 2a has a four-hemisphere shape with the same diameter as the spherical diameter of the arm side attachment part 1a,
The other surface side is a convex sphere (i) whose radius is the center of the mounting portion 2a.
2b (see Figure 3).

Reference numeral 3 denotes a presser plate which is made of an elastic body, and the needle bar swinging arm 2 is attached to the tip end of the presser plate.
A concave hemispherical portion 3a having the same diameter as the convex spherical portion 2b is formed.

This presser plate 3 is fixed to the arm by the uneven boss parts lb and lc of the arm 1, as shown in FIG.
The mounting portion 2a (2b) of the needle bar swing arm 2 is rotatably pressed against the needle bar swing arm 2 (FIG. 2).

On the other hand, a U-shaped guide groove 20 is provided at the lower end of the needle bar swinging arm 2 in parallel to the direction of movement of the swinging arm. 4 is an eccentric shaft with a driver groove 4a at the tip.
The base 4b of the arm 1 is fitted into the mounting hole 1d of the arm 1 and fixed with a screw 5. Thus, the guide groove 20 of the needle bar swing arm 2 is slidably fitted into the eccentric shaft 4 (sixth
(see figure). Next, the operation of this embodiment will be described with reference to FIGS. 6 to 10. When the gap α'' (Fig. 8) between the needle 6 and the front surface 7a of the thread catcher of the inner hook 7 is large as shown by α in Fig. 7, the tip 7b of the inner hook is located outside of the loop 8 of the thread. To prevent this, to adjust to obtain the optimum needle hook clearance α゛ (Fig. 8), tighten the eccentric shaft 4 by loosening the screw 5 and using the dry me groove 4a. , rotate the eccentric shaft 4 clockwise.Then, the eccentricity amount a (Fig. 6)
With this adjustment, the needle bar 9 assembled to the needle bar swinging arm 2 and the needle 6 attached thereto are brought closer to the front surface 7a of the thread catching portion of the inner hook to obtain an appropriate clearance.

At this time, in the device of the present invention, the needle bar swinging arm mounting portion 1 of the arm
Since a is a spherical bearing, the needle bar swinging arm 2 rotates slightly between the mounting portion 1a and the four hemispherical shapes 3a of the presser plate 3, causing the swinging arm 2 to twist and move. No defects will occur. After obtaining the appropriate clearance above, screw 5 at that position.
Tighten to fix the eccentric shaft 4 to the arm 1 again. It goes without saying that if, contrary to the above, the needle hook clearance is too small, the eccentric shaft should be rotated in the opposite direction to the above operation.

Therefore, the following modified embodiment is also possible. That is, (1) The attachment portion 2a° (arm side) of the needle bar swinging arm 2 is made conical (see FIG. 11).

(2) The concave hemispherical portion of the presser plate 3 is made into a cone or circular hole 3a'' (see FIG. 12).

(3) As shown in FIG. 13, an arm and a needle bar swinging arm.

Spherical surface joint portions 1a'', 2a'', 2b'', 3 of each presser plate
Example diagram (illustrated in Figure 2.3) where the unevenness of “a” was explained earlier.
It is the reverse form of .

〔Effect of the invention〕

In the prior art device, the necessary means to optimize the gap between the sewing machine needle and the front surface of the thread catcher of the inner hook to prevent skipped stitches is carried out by moving the needle bar swinging arm perpendicular to its movement direction. The problem was that it could not be done.

In the present invention, since the attachment portion between the arm and the needle bar swinging arm is a spherical bearing, the above-mentioned problem does not occur.

In addition, since the attachment parts of the arm and the swinging arm are not spherical, the four hemispherical parts of the needle bar swinging arm can be placed at any position on the convex hemisphere of the arm, and the four hemispherical parts of the needle bar swinging arm can be placed at any position on the convex hemisphere of the swinging arm. Even if you press the swinging arm holding plate and assemble the swinging arm in the position, the swinging arm will automatically move toward the center of the ball and return to the normal position due to the break-in operation of the swinging arm in the later process. Return. Therefore, the assembly work is quick and easy, and automatic assembly is also possible.

[Brief explanation of drawings]

Fig. 1 is a developed view of the parts arrangement of one embodiment of the device of the present invention;
6 to 6 are explanatory diagrams of the attachment relationship of the needle bar swing arm, in particular, FIG. 5 is a side view of FIG. 4, FIGS. 7 and 8 are explanatory diagrams of the needle hook clearance relationship, and FIG. FIG. 10 is a side view of FIG. 9, and FIGS. 11 to 13 are explanatory views of different embodiments. 1... Arm, 2... Needle bar swinging arm, 3... Presser plate, 4... Eccentric shaft, 6... Needle, 7... 1 Ishishi Seitei representative of 7 companies Figure 1, Figure 2, g3g, Figure 4, Figure 6, Figure 7, Figure 18, s9, and Figure 10.

Claims (1)

[Scope of Claims] In a sewing machine in which a needle bar swings, one side of the upper end portion is attached to a needle bar swinging arm mounting portion having a hemispherical surface integrally formed on the upper part of the face plate side of the arm. The same diameter as the spherical diameter of the part,
a needle bar swinging arm having a hemispherical attachment portion having a radius around the center of the hemispherical shape on the other side; the attachment portion provided on the arm and the attachment portion on one side of the needle bar swinging arm are located between each other; A needle bar swing arm holder for a sewing machine that is rotatably pressed by an elastic presser plate that has a spherical part that forms a perfect spherical joint that is a combination of concave and convex or vice versa and is joined to a hemispherical surface on the other side. Device.