JPS5836391Y2 - Overlock sewing machine presser device - Google Patents

Description

[Detailed description of the invention] This invention relates to a presser foot device for a sewing machine, and in particular includes a presser foot that is pivotally supported on a sewing machine frame, a presser foot that is pivotally supported on the presser foot, and a presser foot that is attached to the presser foot. The presser foot is unilaterally biased and the presser foot is brought into elastic contact with the throat plate or the feed dog by a spring, which feeds the fabric in cooperation with the four-movement feed dog.The presser foot is synchronized with the movement of the feed dog. This is a presser foot device for overlock sewing machines that moves back and forth to prevent sewing misalignment between the upper and lower layer fabrics.The purpose of this device is to have a simple structure, high durability, and to keep the presser foot on the needle. It is an object of the present invention to provide a novel type of presser foot device for an overlock sewing machine, which can adjust the strength of a spring pressed against a plate.

To explain this with reference to the drawings, reference numeral 1 denotes a presser foot whose one end is pivotally attached to the sewing machine frame 2 so as to be rotatable horizontally and vertically, and which extends along the side of the sewing machine toward the seam forming mechanism. A presser foot 3 has a presser foot 4 pivotably attached to the presser foot 3.
Reference numeral 7, whose middle part is rotatably supported by a stepped screw 5, is a side plate attached to the base of the presser foot 1 with an appropriate gap between the presser foot and the presser foot, and the screw punch 8 is inserted into the said gap. The amount of protrusion can be adjusted by rotating the screw.

Reference numeral 9 has a concave plate 9a formed at one end with its intermediate portion supported by a pipe 11 loosely fitted to a screw 10 for attaching the side plate 7.
It is a plate spring in which a shaft opening to be fitted into the screw punch 8 is fitted, and a snow tray 9b formed at the other end is brought into contact with the presser foot 3- side from below, and the strength of the spring is rotates the screw punch 8,
It is adjusted by changing the amount of protrusion.

Reference numeral 13 denotes a bracket having a cross-sectional shape that is attached to the presser foot 1 so as to cover the presser foot side. It functions as a stopper that prevents the presser foot from rotating.

Next, the feeding action of this device will be explained.

In FIG. 4, during the movement period (al) in which the feed dog performs four movements, it rises above the throat plate 15 and reaches the highest point, the presser foot 4 rotates around the step screw as the feed dog 16 rises. Ascends and moves in the opposite direction to the feed dog movement direction (
(in the direction of the solid line arrow) During this time, the upper layer of the workpiece fabric fed by the feed dog is subjected to frictional resistance from the presser foot moving in the opposite direction, but this friction is kinetic friction compared to the static friction that occurs in conventional presser devices, and the coefficient of kinetic friction is Since the coefficient of static friction is lower than the coefficient of static friction, the deceleration of the upper layer cloth by the presser foot is minimized, and the uniformity of feeding of both the upper and lower layer cloths is improved.

Next, in the movement section (1) c) until the feed dog 16 sinks into the throat plate from the highest point, the presser foot descends as the feed dog descends and moves back in the feeding direction of the feed dog (dotted line arrow direction).

During this time, the presser foot has a function as an upper feeding mechanism, and provides a feeding action to the upper layer fabric, thereby further increasing the uniformity of feeding of both the upper and lower layer fabrics.

As described above, the fabric presser device of this invention moves back and forth in synchronization with the movement of the feed dog, and prevents misalignment of sewing between the upper and lower layer fabrics. The structure is relatively simple because it consists of the adjustment means for the spring, and the presser foot that supports the presser foot is more durable than the wire spring shown in Japanese Utility Model Application No. 54-58459. The presser foot only needs to have the function of biasing the presser foot in one direction, and there is no need to use a specific spring, and its strength can be adjusted by the adjustment means to adjust the presser foot pressure.

Moreover, since this adjustment means is not limited to a specific spring, it does not need to be of a specific structure, and the mounting position can be set to a preferable position as long as the spring acts on any position on the presser foot. be able to.

[Brief explanation of drawings]

The figures show the presser foot device according to the present invention, and Fig. 1 is a side view of the sewing machine equipped with the presser foot device, Fig. 2 is a sectional view, Fig. 3 is a partially cutaway plan view, and Fig. 4 is a side view of the sewing machine equipped with the presser foot device. is an action explanatory diagram. 1... Presser foot, 3... Presser foot, 4...
...Presser foot, 5...Step screw, 7...
... Side plate, 8 ... Screwdriver, 9 ... Spring,
13... Bracket, 15... Throat plate,
16...Feed dog.

Claims (2)

[Scope of utility model registration request] (1) A presser foot 1 rotatably attached to the sewing machine frame 2, a presser foot 3 whose intermediate portion is pivotably attached to the presser foot 1 and can be rotated in the vertical direction, and a presser foot 3 attached to one end of the presser foot. A presser foot 4 to be attached, a spring 9 that biases the presser foot in one direction and brings the presser foot into elastic contact with the throat plate 15 or the feed dog 16, and an adjustment that can adjust the strength of the spring. means and a feed dog 16
The presser foot pivots on the presser foot as it moves up and down on the throat plate.The presser foot moves in an upward arc around the pivot point as a fulcrum, and feeds the fabric in cooperation with the feed dog. Sewing machine presser foot device. (2) The spring 9 is a plate spring attached to the side of the presser foot 1, and the adjustment means is a screw punch 8 that is screwed onto the presser foot and whose protruding end touches the plate spring and can be rotated. A presser foot device for an overlock sewing machine according to claim 1.