JPH0135728Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to a feed dog mechanism in sewing machines, especially sewing machines used for sleeve attachment, etc., that feeds the sewing product in a predetermined direction in accordance with the sewing operation of the sewing needle. .

[Conventional technology]

4 to 8 are diagrams showing the prior art.

Figure 4 is a front view of a so-called cylinder bed type sewing machine used for sewing sleeve attachments, etc. As is clear from the figure, the sewing machine bed MB is located above the sewing machine table surface, and is suitable for sewing cuffs etc. It's getting old.

FIG. 5 is a plan view of part A in FIG.
In detail, FIG. 6 is a plan view showing the sewing machine feed dog mechanism at the tip of the sewing machine bed, FIG. 6 is a longitudinal sectional view of the same as above, FIG.
FIG. 8 is an exploded perspective view of the main components of the feed dog mechanism.

In the figure, numeral 6 denotes a feed dog which is fixed by a screw 8 to the upper surface of the other end of the feed arm 7 whose one end (the right end in the figure) is pivotally supported, and which operates integrally with the feed arm 7.

Also, a swing pin 9 is provided on the lower surface of the tip of the feed arm 7.
is fixed by a nut 10, and the lower end of this swing pin 9 is in contact with the outer peripheral surface of an eccentric cam 11.

Then, due to the rotation of the eccentric cam 11, the swing pin 9
Since the feed arm 7 reciprocates in the vertical direction, the tip of the feed arm 7 also reciprocates in the vertical direction, causing the feed dog 6 to reciprocate in the vertical direction.

14 is a lower shaft that drives the hook 17, the eccentric cam 11, etc.

The gear portion 14a of the lower shaft 14 is connected to the eccentric cam 11.
The eccentric cam 11 is rotated by engaging with a gear portion 11a provided on the inner circumferential surface of the cam. 12 is an eccentric cam 11
13 is a cam retainer, and 1
6 is a presser lid.

Further, reference numeral 15 denotes a horizontal feed shaft that gives horizontal reciprocating motion to the feed dog 6 via the horizontal feed arm B. Due to this horizontal movement and the above-mentioned vertical movement, the feed dog 6 makes an elliptical movement, so-called four movements, and smoothly feeds the fabric, etc.

Furthermore, 4 is a throat plate base for indicating the throat plate 5, and this throat plate base 4 is provided with a square hole 4a, and the feed arm 7
This is because the swing pin 9 moves as the end of the swing pin 9 reciprocates in the horizontal direction (left and right direction in FIG. 7).

[Problem that the invention attempts to solve]

However, the conventional feed dog mechanism described above has the following problems.

(a) A broken sewing machine needle or thread scraps may fall into the cam receiver from the square hole in the throat plate base and become caught between the outer circumferential surface of the eccentric cam and the inner circumferential surface of the cam receiver. This may cause the eccentric cam to lock.

(b) Depending on the sewing conditions, it may be necessary to change the height of the feed dog from the throat plate, but this height adjustment is performed by replacing various large and small swing pins. However, since the upper end of the swing pin is fixed to the feed arm with a nut, replacing it takes time and requires complicated work.

[Means for solving problems]

This idea involves forming a hole in the throat plate base that is large enough to allow the swing pin to move up and down, and supporting and mounting the swing pin in this hole. This is an attempt to solve the above-mentioned conventional problems by having the lower end slide in contact with the outer circumferential surface of the eccentric cam.

[Effect]

In the feed dog mechanism according to this invention, since the peripheral wall of the insertion hole of the swing pin formed in the throat plate base is almost in close contact with the swing pin, various foreign objects may fall from there and interfere with the operation of the eccentric cam. Moreover, since the swing pin is simply installed in the insertion hole of the throat plate base, its replacement is easy.

〔Example〕

An embodiment of this invention will be described based on the drawings. Note that the same parts as in the conventional example are given the same reference numerals, and detailed explanation will be omitted.

1 to 3 are diagrams showing one embodiment of the feed dog mechanism according to this invention. FIG. 1 is a plan view of the feed dog mechanism near the tip of the sewing machine bed, and FIG.
The figure is a sectional view taken along the - line in Figure 1, and Figure 3 is a
FIG. 3 is an exploded perspective view of the feed dog mechanism.

The swing pin 9 is attached to the mounting hole 4 formed in the throat plate base 4.
The upper end is in contact with the lower surface of the feed arm 7, and the lower end is in contact with the outer peripheral surface of the eccentric cam 11.

The mounting hole 4a is formed to have a diameter that allows the swing pin 9 to move up and down and to the extent that no gap is created between the two. 20 is a washer interposed between the presser cover 16 and the cam presser 13.

This washer 20 can prevent lint and other foreign matter from entering the vicinity of the eccentric cam 11 from the direction of the hook 17.

Since this embodiment is configured as described above, the swing pin is not restricted by the reciprocating movement of the feed arm 7 in the horizontal direction (left and right direction in FIG.
1, it slides within the mounting hole 4a and reciprocates up and down to ensure proper vertical movement of the feed dog 6.

[Effect of idea]

Since this invention has the above-described structure, it is possible to almost completely prevent foreign matter from entering the vicinity of the eccentric cam from around the swing pin, and it also has the advantage that the swing pin can be easily replaced.

[Brief explanation of the drawing]

Fig. 1 is a plan view of the vicinity of the feed dog mechanism according to this invention, Fig. 2 is a sectional view taken along the line - in Fig. 1,
FIG. 3 is an exploded perspective view of one embodiment of this invention, and FIGS. 4 to 8 are explanatory diagrams of the prior art.
Fig. 4 is a front view of the cylinder bed type sewing machine, Fig. 5 is a plan view of part A in Fig. 4, Fig. 6 is a vertical cross-sectional view of the vicinity of the feed dog mechanism, and Fig. 7 is a - line in Fig. 6. The sectional view, FIG. 8, is an exploded perspective view of the feed dog mechanism. 6... Feed dog, 7... Feed arm, 9... Swing pin, 11... Eccentric cam.

Claims (1)

[Scope of utility model registration request] The gear part on the end of the lower shaft is engaged with the gear part on the inner peripheral surface of the eccentric cam to rotate the eccentric cam, and the swing pin interposed between the outer peripheral surface of the eccentric cam and the end of the feed arm Therefore, in a feed dog mechanism of a sewing machine which is configured to follow the rotation of an eccentric cam to obtain vertical reciprocating motion of a feed dog attached to the end of the feed arm, the swing pin is connected to the end of the feed arm with its upper end. A feed dog mechanism for a sewing machine, characterized in that the feed dog mechanism is supported by mounting holes formed in a throat plate base so that the bottom surface and the bottom end thereof abut against the outer peripheral surface of an eccentric cam.