JPH0246858Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] Industrial Application Field The present invention relates to a bobbin case for an industrial zigzag sewing machine.

Conventional technology Conventionally, the bobbin case (hereinafter referred to as "bobbin case") in industrial zigzag sewing machines was
The bobbin thread necessary for stitch construction is passed from the bobbin containing the bobbin thread stored in the bobbin case to the tip of the bobbin thread tension adjustment spring screwed onto the bobbin case skirt.
Pass through the space between the skirt part and the needle hole of the throat plate,
A stitch is obtained by intersecting the upper thread scooped up by the shuttlecock, but since it goes directly to the needle hole diagonally above from the tip of the bobbin thread tension adjustment spring, in the case of zigzag stitching, the needle position may shift from side to side. Because of the movement, the lower thread that is pulled out from the tip of the lower thread tension adjustment spring is always pulled out at different angles. For this reason, when the needle moves to the left, the bobbin thread tension tends to be strong, and when the needle moves to the right, it tends to weaken, etc., and the tension of the bobbin thread becomes uneven. This caused problems due to the formation of tight seams.

As a countermeasure, the bobbin thread is not guided directly from the tip of the bobbin thread tension adjustment spring to the needle hole in the throat plate, but by providing a thread guide between the two, so that the bobbin thread is always pulled out uniformly from the tip of the bobbin thread tension adjustment spring. There are things that are designed to help you. For example, various designs have been devised, such as those with a plate-shaped thread guide attached to the bobbin case head and those with a coil-shaped thread guide attached to the outer periphery of the bobbin case. There was a desire for something that could be easily manufactured.

Problems to be solved by the invention All of the above methods require separate components such as leaf springs and coiled thread guides, and their installation requires complicated work such as screwing and soldering. .
The present invention does not require any separate members and is very easy to install.

[Structure of the idea]

Means for Solving the Problems The present invention is directed to one side 5 of the positioning window 4 formed in the skirt portion 3 of the bobbin case when the bobbin case is stored in the inner hook, and the tip of the bobbin thread tension adjustment spring. The end of the tongue piece 13 cut into a U-shape, leaving the lower edge 10 of the skirt part, is inserted into the bobbin cage at approximately the midpoint of the vertical distance from the small hole 9 that engages the claw formed in the skirt part. Bend the end of the tongue into the groove 12 provided in the head of the bobbin case, braze the end of the tongue to the bottom of the groove, secure it immediately by soldering, etc., and attach it to the upper part of the skirt of the bobbin case. A half-moon-shaped thread guide hole 14 is provided between the skirt portion and the tongue piece 13.

Operation With the above-described structure, the bobbin thread pulled out from the tip 7 of the bobbin thread tension adjustment spring goes to the needle hole of the throat plate via the thread guide hole 14. As shown in Fig. 3, even if the position of the needle moves from side to side, it is always pulled out in a constant state, and the tension of the bobbin thread is always constant.

Embodiment of the invention An embodiment of the invention will be described below based on the drawings.

One side 5 of the positioning window 4 on the skirt portion 3 of the outer periphery 2 of the bobbin case 1 when storing it in the inner hook is engaged with the pawl 8 formed on the tip 7 of the bobbin thread tension adjustment spring 6. At a position approximately halfway between the vertical distance from the small hole 9, the lower edge 10 of the skirt portion 3 is cut and raised in a U shape, leaving about 1 mm, and the cut and raised tongue piece 13 is attached to the head 11 of the bobbin case. The end portion 15 of the tongue piece 13 is quickly fixed to the bottom of the groove 12 by brazing, soldering, etc., and the end portion 15 of the tongue piece 13 is quickly fixed to the bottom of the groove 12. A half-moon-shaped thread guide hole 14 is provided between the skirt portion 3 and the tongue piece 13.

The method of use is to pass the lower thread 19 pulled out from the thread opening 18 of the lower thread tension adjustment spring 6 through the half-moon-shaped thread guide hole 14 according to the present invention, and then guide it to the needle hole of the throat plate.

Effects of the invention By providing the thread guide hole, whether the needle moves to the right or left, the conditions for pulling out the bobbin thread from the tip of the bobbin thread tension adjustment spring remain constant, and the tension of the bobbin thread is always uniform. The phenomenon of so-called uneven tightening is completely eliminated.

In addition, the thread guide hole according to the present invention does not use a separate member like conventional products, but uses a part of the bobbin case body, so there is no need to manufacture or manage parts, and the manufacturing method is also a press. Unlike when other parts are used, the joints are in a fixed state, making soldering and brazing operations simple and cost reductions.

[Brief explanation of the drawing]

Figures 1, 2, and 3 show an embodiment of the present invention, with Figure 1 being a front view, Figure 2 being a side view, and Figure 3 showing the movement of the needle from side to side. This figure shows that although the bobbin thread swings left and right, the state in which it is pulled out from the tip of the bobbin thread tension adjustment spring is always constant. This shows that the state in which the lower thread tension adjustment spring is pulled out from the tip always changes as the needle moves from side to side. 1...Bobbin case, 3...Skirt part, 4...
... Positioning window, 9 ... Small hole, 6 ... Lower thread tension adjustment spring, 13 ... Tongue piece, 14 ... Thread guide hole, 15 ...
... end of tongue piece, 19 ... bobbin thread.

Claims (1)

[Scope of utility model registration request] One side of the positioning window formed on the skirt portion of the bobbin case when storing the bobbin case in the inner hook, and a small hole that engages the pawl formed at the tip of the bobbin thread tension adjustment spring. At approximately the midpoint of the vertical distance, bend the end of the tongue piece cut into a U-shape, leaving the lower edge of the skirt part, into the groove provided in the head of the bobbin case. - A bobbin case for an industrial zigzag sewing machine, characterized in that a half-moon-shaped thread guide hole is provided between the skirt portion of the bobbin case and the tongue piece in the upper part of the bobbin case.