JPS6112944Y2 - - Google Patents

Description

[Detailed explanation of the invention] This design allows the upper feed dog of the overlock sewing machine to match the fabric so that it can stably contact the fabric during sewing, and allows flexibility in adjusting the upper limit of the upper feed dog up or down in response to changes in the thickness of the fabric. This relates to an upper feed dog lower pressure device for an overlock sewing machine, characterized in that the upper feed dog mounting guide 3, which itself has no longitudinal sliding ability, is pressed by a spring in order to hold the upper feed dog. The purpose of this is when the upper feed dog mounting base slides in the front and back direction,
The purpose is to press the upper feed dog mount, which is the sliding body, with a spring to enable smooth sliding without causing creases on the sliding surface of the upper feed dog mount guide.

Conventionally, a device for adjusting the pressure amount of the upper feed dog of an overlock sewing machine was previously developed in Utility Application No. 58-073544 (Utility Model Application No. 178971-1981) and others by the same applicant as the present applicant. There is a device in which the upper feed dog mount, which slides in the front and back direction inside the upper feed dog mount guide, is adjustable and pressed by a spring via a pressure roll. In this case, the sliding movement body, which is the upper feed dog mount, is pressed from above, and the outer surface of the upper feed dog mount is in good condition compared to the inner surface of the upper feed dog mount guide. Unable to maintain a parallel relationship, the inner surface of the upper feed dog mount guide tends to tilt due to the pressure, and the sliding surfaces of the two become particularly oblique, resulting in a squeak phenomenon between the two during sliding. It was discovered that this may cause a defect that inhibits smooth sliding movement.

However, in the present invention, instead of pressing the upper feed dog mount, which is the sliding body itself, with the spring, the upper feed dog mount guide into which it is inserted is pressed with the spring. Therefore, the pressing has no effect on the fitting and sliding state of the upper feed dog mount guide and the upper feed dog mount, and a parallel sliding surface is maintained between them. It is highly effective because it can be used continuously, and there is no risk of creaking or the like, and smooth sliding action can be achieved.

I will now explain in detail the accompanying drawings showing an example of implementation. 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 designates an upper feed dog mounting guide, which is formed into a rectangular tube shape and is pivotally supported at the tip of the device stand 1 by a shaft 3a. The upper feed dog mount 4 is inserted into the inside of the upper feed dog mount guide 3 so as to be slidable in the front and rear directions. Reference numeral 5 denotes a spring, which is embedded in the sewing machine body or the like so that its tip presses against the upper surface of the upper feed dog mounting guide, and its base end is used to adjust the elastic force of the spring with an adjustment screw 6. . 7
is an upper feed dog, and 8 is a presser foot.

The present invention is constructed as described above, and by adjusting the adjusting screw 6 according to the thickness of the sewing material, the upper feed dog mounting guide 3 can be easily determined to the optimum pressing amount of the upper feed dog 7 using the spring 5. In addition, when there is a change in the thickness of the fabric, such as at a seam part, the upper feed dog mounting guide 3 moves up and down according to the thickness of the fabric using the spring 5, and adjusts the upper feed dog appropriately. It is possible to press the upper feed dog mounting base 4 to achieve a good sewing effect, and instead of the upper feed dog mounting base 4 being a sliding member, the upper feed dog mounting base guide 3 into which it is slidably inserted is used. Under the pressure of the spring 5, the sliding surface itself does not change its parallel state in any way and can slide smoothly.
Good sewing is possible without the risk of such problems occurring.

The lower end of the spring 5 may be attached so as to directly press the upper surface of the upper feed dog mount guide 3, but if necessary due to the relationship with other structural members, the lower end of the spring 5 may protrude laterally as shown in Fig. 1. 9 may be provided to press the protrusion 9, but this should be done arbitrarily.

[Brief explanation of the drawing]

The attached drawings show an example of the implementation of the present invention.
The figure is a perspective view of the main parts of the main part, Figure 2 is a side view of the mechanism,
FIG. 3 is a reference diagram illustrating the squeaking phenomenon. 1... Upper feed dog vertical swing device base, 2... Work presser lifting shaft, 3... Upper feed dog mounting base guide, 4... Upper feed dog mounting base, 5... Spring, 6... Adjustment screw rod ,7
... Upper feed dog, 8 ... Presser foot, 9 ... Protrusion.

Claims (1)

[Scope of utility model registration request] The base of the upper feed dog vertical swing device stand 1 is rotatably supported on the presser foot lifting shaft 2, and the upper feed dog mounting base guide 3 is pivotally supported on the tip of the upper feed dog vertical swing device stand 1.
An overlock sewing machine characterized in that an upper feed dog mounting base is fitted in the interior of the machine so as to be slidable in the front and back direction, and the upper feed dog mounting base guide 3 is equipped with a spring 5 to adjustably press the upper feed dog mounting base. Upper feed dog lower pressure device.