US2783725A - Fabric advancing means in sewing machine - Google Patents

Description

March 5, 1957 YASUKATA EGUCHI FABRIC ADVANCING MEANS m sawmc MACHINE Filed Nov. 6, 1953 2 Sheets-Sheet l YIIHII I NVENTOR msumm EGUC/I/ ATTORNEY;

March 1957 YASUKATA EGUCHI 2,783,725

FABRIC ADVANCING MEANS IN SEWING MACHINE Filed Nov. 6. 1953 2 Sheets-Sheet 2 KW T Li INVENTOR YAsu rnr/I 9am;

q...) Maw 4J ATTORNEYS United States Patent FABRIC ADVANCING MEANS IN SEWING MACHINE Yasnkata Eguchi, Tokyo-to, Japan, assignor to Janome Sangyo K. K., Tokyo-to, Japan Application November 6, 1953, Serial No. 390,691

1 Claim. (Cl. 112-215) This invention is concerned with a new and improved sewing machine. More particularly, the invention relates to an improved fabric advancing means in sewing machines wherein two links support the feed dog at the ends, the up-and-down movement of the vertical action arm, and the back-and-forth movement of the horizontal action arm, being caused to act on said links. In this way a composite movement, made up of both said vertical component and said horizontal component, is delivered to the feed dog.

A preferred embodiment of the present invention is shown in the appended drawing, including Figures 1 to 4, wherein:

Figure 1 is a cross-sectional view taken on line 1-1 of Fig. 2;

Figure 2 is a perspective view of a sewing machine embodying the novel fabric advancing means;

Figure 3 is an exploded view;

Figure 4 represents the locus of the fabric advancing feeding movement, in accordance with the invention.

Figure 5 shows a conventional fabric advancing means; and

Figure 6 shows a diagram of the feed movement.

The construction and operation of the fabric advancing means of the present invention will be explained with reference to the appended drawings. Referring more specifically to Figs. l-3, 2 is the horizontal action rocking shaft or rod, and 3 is the vertical action rocking shaft or rod installed in the bed 1 of a bag making type of sewing machine. When the vertical action rod 3 is driven by the main shaft, the horizontally extending vertical action rocker arm 4 connected thereto moves the vertical action link 8 connected to the vertical action arm 4 up and down. Since one end of the feed dog 12 is connected to the vertical action link 8 by the pin 10, this end of the feed dog 12 consequently makes an up-and-down movement. The fabric contacting member 13 is secured to feed dog 12 and moves together therewith. A sliding member 5 fixed at the forward end of said vertical action arm 4 fits in the branches of horizontal extending arm 6 of the fork member 7, and actuates the fork member 7 to move up and down while sliding between the branches of arm 6. The fork member 7 is connected to the horizontal action rod 2 by the pins 14 and 15, so that it is rockable around these pins 14 and 15. The other end of the feed dog 12 is connected to the fork member 7, the pin 11 passing through the apertured lug in the feed dog 12 into the aperture 16 in the fork member 7. Thus, when the vertical action arm 4 moves up and down, the fork member 7 delivers the up-and-down movement to the other end of the feed dog 12 while rocking around the pins 14 and 15. The movement of the horizontal action arm 2 is delivered to the feed dog 12 through the fork member 7 connected to the horizontal action arm 2 by the pins 14 and 15.

It will be seen from the foregoing description that the feed dog 12 is supported by the vertical action link 8 and the fork link 7 at both its ends, and that the composite movement, made up of the back-and-forth component derived from the horizontal action arm 2 and the up-and-down component derived from the vertical action arm 4, is delivered to the feed dog 12 to operate and advance the fabric.

In Fig. 2, 17 is the bobbin case holder assembly, 18 is the means to give zigzag movement to the bobbin case holder assembly 17, and 19 is the main drive shaft in the bed 1 of the sewing machine. The shaft 19 is connected to rocker shafts 2 and 3 by levers, shown but not numbered, and imparts movement to these shafts through the levers.

The advantages of the fabric advancing means of the present invention will now be described. In Fig. 5, a conventional fabric advancing means heretofore used in sewing machines is shown. feed dog 21 is supported directly by the horizontal action arm 22 and the vertical action arm 23, and by the composite movement thereof the advancing or feed movement is made in a locus 25 as shown in Fig. 6. With such construction the ideal locus of a rectangle is not traversed by the feed teeth, but rather the advancing or feed teeth 24 move obliquely to the face plate A--A.

According to the present invention the feed dog 12 is supported by the two links 7 and 8 at the same height as the horizontal action arm 2. The feed dog 12 is thus always maintained horizontal in both horizontal movement and vertical movement, so that the locus of movement is ideal as shown at 26 in Fig. 4. Further, according to the present invention, the length of the feed dog can be greatly reduced, and only a minimum space is required to install the assembly in such types of sewing machines as portable machines having beds suitable for bag making. The fabric advancing means of the present invention therefore represents a distinct step forward in sewing machine constructions.

Various changes and modifications in the invention, a preferred embodiment of which has been described, may be made. These modified constructions, to the extent that they are within the scope of the appended claim, shall be considered as part of the invention.

I claim:

In a feed mechanism for a sewing machine including a main drive shaft, the combination comprising fabric advancing means including a substantially horizontally ex- 7 tending feed dog provided with means for contacting the fabric, a vertical action rocking shaft carrying a substantially horizontally extending rocker arm, a horizontal action rocking shaft, means operatively connecting said vertical and horizontal action rocking shafts to said main shaft to be rocked by the latter, first and second links extending substantially vertically and connected to said feed dogs at spaced locations, said first link being pivotally connected to said rocker arm, whereby rocking of said vertical action rocking shaft causes said first link to move vertically, said second link being operatively connected with said horizontal action rocking shaft and being provided with an arm having a horizontally extending slot, and a sliding member carried by said rocker arm and being displaceably positioned in said slot of said arm of said second link, whereby vertical movement of said first link is imparted to said second link so that both spaced locations of said feed dog move vertically together, said feed dog thus being maintained substantially horizontally in all positions of movement.

References Cited in the file of this patent UNITED STATES PATENTS 1,250,437 Devoe Dec. 18, 1917 1,729,994 Card Oct. 1, 1929 2,199,663 Hacklander et al May 7, 1940 2,561,310 Hale July 17, 1951 2,619,058 Keller Nov. 25, 1952 In such a construction, the

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