JPS6114362Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention adjusts the upper feed dog of the overlock sewing machine to the fabric to ensure stable contact with the fabric during sewing, and adjusts the upper limit of the upper feed dog up and down in response to changes in the thickness of the fabric. The present invention also relates to a pressure amount adjustment and lower limit setting device for the upper feed dog of an overlock sewing machine, which sets the lower limit of the upper feed dog to a constant value. Conventionally, this type of sewing machine with an upper feed dog generally does not have a pressure amount adjustment or lower limit setting device for the upper feed dog, and the upper and lower feed dogs collide and mesh with each other on the upper surface of the throat plate, which prevents thin fabrics and scratches. When sewing fabrics that are prone to scratches, if there are scratches or other harmful problems on the sewn product, or there are steps or protrusions in the fabric, and the thickness of the fabric changes, only those areas may be damaged. This had major drawbacks, such as being unable to produce good sewing effects because the sewing machine was under strong pressure from the upper and lower feed dogs.

In order to eliminate such defects, as a device for adjusting the pressure amount of the upper feed dog and setting the lower limit, a spring is attached to an adjusting screw protruding from the base of the upper feed dog vertical swinging device base, the intermediate portion of which is pivoted. The adjustment nut is inserted into the adjusting nut, and the device base is pulled up by the spring, and the upper feed dog mounting base, which is inserted into the upper feed dog mounting guide pivotally supported at the tip of the device base, is indirectly pulled downward. There is a device in which the spring is pushed down, and a screw rod for adjusting the bottom dead center position of the upper feed dog is provided on the cradle of the spring to adjust the lifting amount of the base of the device base and to set the lower limit of the upper feed dog. The distance from the point of action of the spring at the base of the equipment stand to the fulcrum (shaft attachment part) is much shorter than the distance from the fulcrum to the tip of the equipment stand, and the relationship between the levers imparts considerably strong elasticity to the spring. If you do not use one that has one, you will not be able to adequately adjust the amount of pressure on the upper feed dog, making it difficult to achieve a good sewing effect.
Furthermore, if a strong spring is used, it is difficult to finely adjust the amount of pressure applied by the adjusting nut, which is a similar drawback, and this is a major drawback that can cause failure of the spring insertion portion. Furthermore, since the lower limit is set using a strong spring, it is difficult to make delicate settings that are essential for this type of sewing work, which is a major drawback as it may cause failure of the screw for adjusting the bottom dead center position. It is something.

However, in the present invention, since the upper feed dog mounting base in front of the upper feed dog vertical swing device base is directly pressed by the spring, the pressing force of the spring acts directly on the upper feed dog mounting base. Even without using such a strong spring, the amount of pressure on the upper feed dog can be adjusted sufficiently, the amount of pressure can be finely adjusted, and a good sewing effect can be achieved. When setting the lower limit, the lower limit is not used as a spring, so the lower limit can be easily set using the upper feed dog lower limit setting screw, which is of great utility.

Reference will now be made in detail to the accompanying drawings, which illustrate an example of the implementation of the present invention.

Reference numeral 1 denotes an upper feed dog vertically swinging device stand, the base of which is rotatably supported on a presser foot lifting shaft 2. Reference numeral 3 denotes an upper feed dog mounting base guide, which is formed into a rectangular tube shape and is pivotally supported at the tip of the device base 1 with a shaft 3', inside which the upper feed dog mounting base 4 can be slid freely in the front and back direction. It is inserted into the 5 is a pressure roll with an upper feed dog mounting base, 6 is a bearing, and the shaft 5' of the pressure roll 5 is
The base is rotatably supported on the tip of the upper feed dog mount guide 3 by a shaft 6', and the press roll 5 is used to rotate the raw end of the upper feed dog mount 4. It is a device that presses the part. Reference numeral 7 denotes a spring, which is embedded in the sewing machine body 8 or the like so as to press the top surface of the tip of the bearing 6 at one end, and adjusts the pressing force of the upper feed dog mounting base 4 with an adjustment screw 9 installed at the other end. It is something to do. Reference numeral 10 denotes an upper feed dog lower limit setting screw rod, which is installed on the base protrusion 1' of the device stand 1 as shown in FIG.
0' is brought into contact with the sewing machine body 8 to set the lower limit of the vertical movement of the upper feed dog vertical swing device base 1, and to set the lower limit of the upper feed dog 11 fixed to the tip of the upper feed dog mounting base 4. be. 12 is a presser foot.

The present invention has the above-mentioned structure, and when using it, adjust the adjustment screw 9 according to the thickness of the sewing fabric.
By adjusting the spring 7, since the spring 7 is not so strong, the optimum pressing amount of the upper feed dog 11 can be easily determined, and there is no risk of failure such as wear of the adjusting screw 9. In addition, when there is a change in the thickness of the fabric such as a seam part of the fabric, the upper feed dog 11 expands and contracts the spring 7 via the upper feed dog mounting base 4, the press roll 5, and the bearing 6 to easily separate the fabric. It operates according to thickness and thickness, and can produce good sewing effects. Furthermore, since the lower limit of the upper feed dog 11 can be easily set by adjusting the lower limit setting screw 10, the gap between the upper feed dog 11 and the lower feed dog can be set to an arbitrary constant value when sewing thin fabrics or fabrics that are easily damaged. This allows sewing to be performed while maintaining the same value, and does not cause scratches or other harmful problems to the sewn product.

[Brief explanation of the drawing]

The accompanying drawings show an example of the implementation of the present invention, and FIG. 1 is a perspective view of the main parts of the device of the present invention, and FIG. 2 is a mechanical diagram showing the operation of the present invention. 1... Upper feed dog vertical swing device stand, 1'... Base protrusion, 2... Material presser lifting shaft, 3... Upper feed dog mounting base guide, 3'... Shaft, 4... Upper feed dog mounting base, 5... Upper Feed dog mount press roll, 5'...shaft, 6...bearing, 6'...
Shaft, 7... Spring, 8... Sewing machine body, 9... Adjustment screw, 10... Upper feed dog lower limit setting screw, 10'... Tip, 11... Upper feed dog, 12... Fabric presser foot.

Claims (1)

[Scope of utility model registration request] The base of the upper feed dog vertically swinging device stand 1 is rotatably supported on the presser foot lifting shaft 2, and the inside of the upper feed dog mounting base guide 3, which is pivotally supported at the tip of the device stand 1, is moved in the front and back direction. A pressure roll 5 for pressing the sliding upper feed dog mount 4 is provided, a bearing 6 for pivotally supporting the roll 5 is pivotally supported by the mount guide 3, and the bearing 6 is pressed with a spring 7 in an adjustable manner. An upper feed overlock sewing machine characterized in that an upper feed dog lower limit setting screw 10 is provided on the protrusion 1' of the base part of the device stand 1, and the upper feed dog lower limit setting screw 10 is arranged such that the tip 10' comes into contact with the sewing machine main body 8. Tooth pressure adjustment and lower limit setting device.