JPH01299585A - Hem-stitch sewing machine - Google Patents

Abstract

PURPOSE:To ensure a surplus thread quantity proportionate to a stitching width and form a seem having no projection, etc. by separately moving a lower knife holder and a stitch supporting body at different moving quantities by the action of a cam member and making the moving quantity of the stitch supporting body larger than the moving quantity of the lower knife holder. CONSTITUTION:As an adjusting member 20 is rotated in accordance with the indication of a scale 22 corresponding to a stitching width, a lower knife holder 8 holding a lower knife 7 is moved in the direction perpendicularly intersecting to a cloth feeding direction by the action of a first cam member 23, while moving a holding member 15 having a stitch supporting body 17 by the action of a second cam member 24, to adjust a stitching width. At this time, the displacement quantity of the second cam member 24 is larger than the displacement quantity of the first cam member 23. At the time of forming a hem stitching seem while cutting the end edge of machining cloth W, the stitching seem is temporarily held between both stitch supporting bodies. In this case, as a stitching width is made large, since the moving quantity of the stitch supporting body 17 is larger than that of the lower knife holder 8, the movable stitch supporting body 17 is separated from a fixed stitch supporting body 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an overseam sewing machine that forms an overseam seam while cutting the edge of a work cloth.

[Prior Art] As a conventional overlock sewing machine of this type, one having a configuration as shown in, for example, Japanese Utility Model Application Publication No. 59-67169 is known. In this conventional configuration, the lower knife holder that holds the lower knife is provided so as to be movable in a direction perpendicular to the cloth feeding direction, and by rotating the adjustment knob, the lower knife holder is moved through the engagement between the male thread and the female thread. It has been moved so that the stitch width can be adjusted. and,
A stitch support is mounted on the lower knife holder, and the stitch support is moved together with the lower knife when adjusting the stitching width.

[Problems to be Solved by the Invention] However, in general, upper and lower louver yarns have a reciprocating amount of yarn depending on the stitching width from the needle drop point to the edge of the fabric, and an increase in the stitching width due to the spread in the fabric feeding direction. In contrast, in the conventional configuration described above, a reciprocating thread amount corresponding to the stitching width is secured, but the stitch support is moved integrally with the lower knife, and the stitch support is moved integrally with the lower knife. Since the positional relationship does not change, it is not possible to secure an amount of extra thread proportional to the stitching width, and there is a problem in that the excess thread amount is insufficient and the stitching width adjustment setting becomes larger, causing tension in the seam. Ta.

This invention was made by paying attention to the point u while existing in the conventional technology, and its purpose is to adjust the overlocking width to create an amount of margin proportional to the overlocking width. To provide an overlock sewing machine which can secure a sufficient amount of thread, can always form a stable seam without tension, etc. regardless of changes in setting of overlock width, and is easy to operate.

[Means for Solving the Problems] In order to achieve the above object, in the overlock sewing machine of the present invention, the edge of the workpiece cloth to be fed to the needle drop position is arranged on the cloth feeding side rather than the needle drop position. An upper knife and a lower knife for cutting edges, a lower knife holder that is movable in a direction perpendicular to the fabric feeding direction to hold the lower knife, and a knife that moves from near the needle drop position to the fabric feeding side. a stitch support that is oriented and movable in a direction perpendicular to the cloth feeding direction; an adjustment member that can be operated to adjust stitch width; and a cam member that is operated by the adjustment member. and a transmission means for individually moving the lower knife holder and the stitch support body by different amounts of movement based on the amount of displacement of the cam member.

[Function] In the hem stitching machine configured as described above, when the adjustment member is operated, the lower knife holder and the stitch support are individually moved by different amounts of movement by the action of the cam member, and the stitch support is moved. The amount of stitching can be made larger than the amount of movement of the lower knife holder, and the stitch support ensures a surplus amount of yarn in accordance with the stitching width.

[Embodiment] Hereinafter, an embodiment of an overlock sewing machine embodying the present invention will be described in detail based on the drawings.

As shown in FIG. 1, a sewing machine main body 1 is composed of an arm portion 2 and a bed portion 3. As shown in FIG. The needle bar 4 is provided on the arm portion 2, and the sewing needle 5 attached to the lower end of the needle bar 4 cooperates with a looper (not shown) provided in the bed portion 3 to move the workpiece cloth W.
Overlock seams S are formed at the edges of the edges. The upper knife 6 is provided on the bed section 3 so as to be movable up and down on the fabric feeding side of the needle drop position, and the upper knife 6 cooperates with the lower knife 7 provided in a stationary state on the bed section 3 to The edge of the work cloth W sent to the needle drop position is cut prior to sewing.

Therefore, to explain in detail the structure for supporting and moving the lower knife 7, the lower knife holder 8 is installed in the bed portion 3 via a pair of support bins 9 so as to be movable in a direction perpendicular to the cloth feeding direction, and the right side of the lower knife holder 8 is A lower knife 7 is fixedly held by a screw 10.

A compression spring 11 is interposed between a spring seat 12 at the tip of each support bottle 9 and the bed portion 3, and the action of this compression spring 11 urges the lower female holder 8 to move toward the left in FIG. ing.

The throat plate 13 is fixed on the bed portion 3 of the sewing machine main body 1, and as shown in FIG. 4, a fixed stitch support 14 is provided near the needle drop position facing toward the fabric delivery side. . The holding member 15 is installed in the bed portion 3 via a pair of support bins 16 so as to be movable in a direction perpendicular to the cloth feeding direction so as to be located near the lower knife holder 8, and has a needle drop position at its upper end. A movable stitch support 17 for temporarily holding an overedge seam S formed by It is provided. A compression spring 18 is interposed between a spring seat 19 at the tip of each support bottle 16 and the bed portion 3, and the action of this compression spring 18 urges the holding member 15 to move toward the left in FIG. ing.

One adjustment member 20 for adjusting the stitching width is a support shaft 2
1 is rotatably attached to the bed portion 3 of the sewing machine body 1, and a scale 2 corresponding to the stitching width is provided on the outer periphery of the sewing machine body 1.
2 is provided. First and second cam members 23.2
4 are integrally formed on both side surfaces of the adjustment member 20, the first cam member 23 is an end cam, and the second cam member 24 is a circumferential cam. In this embodiment, as shown in FIG. 6, the amount of displacement of the second cam member 24 is greater than the amount of displacement of the first cam member 23.

The first transmission lever 25 is connected to the bed portion 3 by means of a support shaft 26.
The lower knife holder 8 is rotatably mounted inside the lower knife holder 8 and is engaged with the first cam member 23 at one end thereof, and engaged with one of the support bins 9 of the lower female holder 8 at the other end. The second transmission lever 27 is rotatably mounted in the bed portion 3 by a support shaft 28, and is engaged with the second cam member 24 at one end, and one support pin of the holding member 15 at the other end. 16. The first and second transmission levers 25.27 then control the cam member 23.
A transmission means is configured to separately move the lower knife holder 8 and the holding member 15 of the stitch support 17 based on the amount of displacement of the stitch support member 17.

Now, in the hem stitching machine configured as described above, when the adjustment member 20 is rotated according to the display on the scale 22 corresponding to the stitch width, the first transmission lever 25 is moved by the action of the first cam member 23. The lower knife holder 8 holding the lower knife 7 is moved in a direction perpendicular to the cloth feeding direction, and the stitch support 17 is provided via the second transmission lever 27 by the action of the second cam member 24. The holding member 15 is moved in the same direction to adjust the stitching width.

At this time, as shown in FIG. 6, since the amount of displacement of the second cam member 24 is larger than the amount of displacement of the first cam member 23, the larger the stitching width is, the more the stitches are stitched than the lower knife holder 8. The amount of movement of the support body 17 increases.

Then, by working together with the upper knife 6 and the lower knife 7, the workpiece cloth W is
While cutting the edge of the stitch support 14 and 17, when an overlock stitch S is formed by the cooperation of the sewing needle 5 and a looper (not shown), as shown in FIG.
is held temporarily. In this case, when the stitching width is increased by adjusting the rotation of the adjusting member 20, the moving amount of the stitch support 17 is greater than that of the lower knife holder 8, so the movable stitch support 17 separates from the fixed stitch support 14. Therefore, not only the yarn amount A for the reciprocating portion of the overlocking width but also the extra yarn amount B become large.

Therefore, by operating only the adjusting member 20, it is possible to always form a stable overlock seam without tension, regardless of changes in the overlock width.

Note that the present invention is not limited to the configuration of the above-mentioned embodiment. For example, the cam member may be provided separately from the adjustment member, and the cam member may be operated via a rotation shaft or the like according to the operation of the adjustment member. The gist of the present invention can be configured such that the lower knife holder and the stitch support body are individually moved by different amounts of movement through transmission levers having different lever lengths etc. by the action of one cam member. The configuration of each part can be changed and implemented as desired without departing from the above.

[Effect of the invention] Since this invention is configured as explained above,
As the stitching width is adjusted, the lower knife holder and the stitch support are moved separately by different amounts of movement, making it possible to secure an amount of surplus thread proportional to the stitching width, so that the stitch support can move with the lower knife. Unlike conventional configurations that are configured to move in one piece, there is no problem that tension occurs in the seam as the stitching width adjustment setting increases, and stable seams are always created regardless of changes in the stitching width setting. This has an excellent effect in that it can be easily operated.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an embodiment of an overlock sewing machine embodying the present invention, Fig. 2 is an enlarged front sectional view showing the structure of a lower knife holder and a stitch support, and Fig. 3 is a cross-sectional view of the same structure. 4 is a partial plan view, FIG. 5 is a plan view showing the state of formation of overlock seams on the edge of the work cloth, and FIG. 6 is a graph showing the amount of displacement of the cam member. 1...Sewing machine body, 5...Sewing needle, 6...Upper knife,
7... Lower knife, 8... Lower knife holder, 17... Stitch support, 20... Adjustment member, 23... First cam member, 24... Second cam member, 25 . . . a first transmission lever as a transmission means, 27 . . . a second transmission lever as a transmission means. Patent applicant Brother Industries, Ltd. Mizunami Seiki Co., Ltd. Agent Patent attorney On 1) Hironobu Figure 3 Figure 5 Section 4 Mori□

Claims (1)

[Claims] 1. An upper knife (6) and a lower knife (7) which are arranged on the cloth feed side than the needle drop position and cut the edge of the work cloth (W) sent to the needle drop position. ), a lower knife holder (8) that is movable in a direction perpendicular to the cloth feeding direction to hold the lower knife (7), and a lower knife holder (8) that is oriented toward the cloth feeding side from near the needle drop position, and A stitch support (17) provided movably in a direction perpendicular to the cloth feeding direction, one adjustment member (20) operable to adjust stitch width, and actuated by the adjustment member (20). cam member (23
, 24), and transmission means (25, 27) for individually moving the lower knife holder (8) and the stitch support (17) by different amounts of movement based on the amount of displacement of the cam members (23, 24).
).