JPH0111183Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a device for adjusting the position of a lower knife when changing the stitch width in an overlock sewing machine.

[Conventional technology]

Conventionally, when edge stitching is performed using an overlock sewing machine, it is necessary to select the stitch width appropriately depending on the purpose of the workpiece, the type of fabric, the number of layers, etc., and it is necessary to change the stitch width. To do so, first replace the throat plate with one that has the specified width of the thread slider, or, if the needle plate has an adjustable thread slider, manually adjust the thread slider by moving it left and right or front and back. In order to determine the optimum position of the hem cutting knife for the above-mentioned swivel width position, it was necessary to remove the cover from the lower surface of the sewing machine table and adjust the position of the lower knife by moving it left and right.

[Problem that the invention attempts to solve]

However, since the conventional lower knife (position) adjustment device was configured as shown in FIG. To do this, loosen the setscrew 43 and move the shaft 42 of the lower knife holder 41, which is pivotally supported on the sewing machine frame 44, as appropriate using a visual guide, check the proper relative position with the upper knife, and fix it again. A method was taken. The above adjustment requires loosening the setscrew 43 many times and repeating fine adjustments by hand, so even if a guideline such as a score line for the knife position is provided, it is especially difficult for novice operators to make the adjustment. This was difficult and time consuming.

The present invention was devised in view of the problems in the conventional lower knife adjustment, and aims to provide a lower knife position adjustment mechanism that can be operated extremely easily and precisely.

[Means for solving problems]

Therefore, in the present invention, the holder shaft fixed to the lower knife holder that holds the lower knife is supported so as to be slidable in the axial direction with respect to the sewing machine frame, and the gear is arranged rotatably on the holder shaft. The above-mentioned object is achieved by configuring the holder shaft to be moved in the axial direction by rotationally driving the attached cam by an adjustment gear fixed on a separate adjustment shaft rotatably supported on the sewing machine frame. This is what I am trying to do.

[Function] With the above configuration, the operator can easily and precisely adjust the lower knife position by rotating the adjustment shaft using the adjustment knob or the like.

〔Example〕

The present invention will be explained below based on examples.
FIGS. 1a and 1b show a side view and a front view of the main parts of the lower knife (position) adjusting device according to the present invention, with the lower cover of the sewing machine table opened. Fig. 2 is an exploded perspective view of each component, and Fig. 3 is an exploded perspective view of each component.
It is an enlarged explanatory view of the main part of the gear meshing part in a figure.

〔composition〕

In the figure, F indicates the sewing machine frame and P indicates the needle plate.
Adjustment knob 1a disposed facing the operator side (the cloth feeding direction is indicated by arrow W) is
The shaft 1 is rotatably supported by a bracket 11 fixed under the frame, and an adjustment gear 2 is fixed with a screw to the opposite end of the adjustment knob. On the other hand, a lower knife holder shaft 4 is fitted into the frame F parallel to the adjustment knob shaft 1 so as to be slidable in the axial direction. A lower knife holder 6 is fixed to one end of the shaft 4, and the lower knife 8 is inserted into the recessed groove 6.
a in parallel to the feed direction, and fix the lower knife holding plate 9 and the lower knife support plate 10 (to prevent the lower knife from shifting downward, and the height of the lower knife can be adjusted with the eccentric hole) by respective setscrews. It is attached through. One side of the lower knife holder 6 has a bifurcated groove 6b, which slides in the axial direction on a guide shaft 7 fixed to the frame F in a cantilevered manner parallel to the lower knife holder shaft 4 with a set screw. It is movably fitted and prevents the lower knife holder 6 from rotating around the shaft 4. In addition, on the opposite side of the lower knife holder shaft 4 from the lower knife 8,
A geared cam 3 integrally having a gear c meshing with the first adjustment gear 2 and a face cam surface a is rotatably fitted. A pin 5 is protruding from the lower female holder shaft 4 adjacent to the back surface of the holder 6, and the tip of the holder shaft 4, which penetrates the frame F with a geared cam 3 interposed therebetween, It is restrained in the axial direction by a retaining ring 13, and by this spring 12, the cam surface a of the geared cam 3 is
It is biased so as to be in constant contact with the pin 5.
Further, a stopper portion b for the pin 5 is provided protrudingly from one end of the cam surface a.

〔motion〕

Next, the operation in the above configuration will be explained. When the operator rotates the adjustment knob 1a in either direction, the geared cam 3 loosely engaged with the lower knife holder shaft 4 via the adjustment gear 2 is driven to rotate. The cam surface a of the geared cam 3 has an inclination for adjusting the steering width from the minimum to the maximum,
In addition, since the stopper b is provided at the minimum/maximum predetermined position, the rotation of the cam 3 causes the lower knife holder 6, which is integrated with the lower knife holder shaft 4, to correspond to the inclination (height) of the cam surface a. position along the guide shaft 7 through the double groove 6a in the cloth feeding direction W.
Move left and right at right angles to.

Since the lower knife position adjustment by the above operation is based on a combination of gears and cams, fine adjustments can be made extremely easily and precisely. Gear ratio is 1
However, the speed may be reduced or increased as necessary. In addition, although spur gears were used in this example,
By using a bevel gear set, the adjustment knob can be arranged at a desired angle, including at right angles to the embodiment. Furthermore, by arranging the adjustment knob so as to be exposed outside the cover of the sewing machine, it is possible to freely adjust it from the outside without having to open the cover.

[Effect of idea]

As explained above based on the examples,
According to the present invention, the lower knife position adjustment operation accompanying the steering width adjustment can be performed extremely easily and precisely by rotating the adjustment knob via gears and cams, improving operability. I can do it.

[Brief explanation of the drawing]

1a and 1b are side views and front views of essential parts of the lower knife adjusting device according to the present invention, FIG. 2 is an exploded perspective view of each component, and FIG. 3 is the gear meshing part in FIG. 1b. FIG. 4 is an enlarged explanatory diagram of essential parts of an example of a conventional lower knife adjusting device. 1...Adjustment knob shaft, 1a...Adjustment knob, 2
...Adjusting gear (gear), 3...Cam with gear (gear), 4...Lower knife holder shaft, 5...Pin, 6...
...Lower knife holder, 7...Guide shaft, 8...Lower knife,
F...Sewing machine frame.

Claims (1)

[Scope of utility model registration request] A lower knife holder in which the lower knife of the overlock sewing machine is arranged parallel to the feed direction, and a holder shaft fixed to the lower knife holder and pivotally supported on the sewing machine frame so that the lower knife can slide in the direction crossing the feed direction. , a geared cam that is rotatably arranged on this holder shaft, a spring that acts on this holder shaft and constantly presses a pin protruding from the shaft against the cam surface of the geared cam, and a gear of this geared cam. A lower knife adjusting device for an overlock sewing machine, comprising an adjusting section that constantly engages and rotates to move a lower knife holder in a direction crossing the feed direction.