JPH036294Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a bobbin holding device used in a full-rotation hook of a sewing machine.

BACKGROUND OF THE INVENTION A fully rotary hook of the inclined hook type is mainly used in which a bobbin housed in a bobbin case is held by a latch lever that is pivotally supported on the upper part of a center post. Figures 4 and 5 show an example of this, in which the upper part of the center post a is slit in the axial direction, a leaf spring b having an L-shaped cross section is caulked to the slit, and the horizontal part of the leaf spring b is attached to the upper part of the center post. A cam d integrally formed with the supported latch lever c is held in elastic contact with the latch lever c to hold it in the solid line position or the dashed-dotted line position, and the bobbin e is held in the horizontal position as shown in the solid line and in the vertical position as shown in the dashed-dotted line. The bobbin e can be attached and detached.

Instead of using a leaf spring to restrain the latch lever in the raised or collapsed state, a coil spring installed inside the center post and a slider that elastically contacts the cam of the latch lever by the action of the spring are used. There are also some that have been made to do so (Utility Model Publication No. 53-32748, Utility Model Application No. 15387-1987).

Problems that the invention aims to solve: In the case of the former device, in which a leaf spring with an L-shaped cross section is installed at the top of the center post, it is not easy to create a slit in the top of the center post, and it is difficult to swage the leaf spring in a narrow space. is not easy. On the other hand, the latter device, in which a coil spring and slider are mounted inside the center post, does not require slit processing on the upper part of the center post or caulking of the leaf spring, but on the other hand, it is difficult to manufacture the coil spring with high precision. The spring pressure tends to become stronger or weaker, and the latch lever operation becomes heavier or lighter, and if it is light, the locking force becomes weak.

The present invention aims to solve the above-mentioned problems when using a coil spring.

Means for Solving the Problems The present invention allows the spring pressure of the coil spring to be adjusted.

That is, the present invention includes a center post protruding from the bottom of a bobbin case or an inner pot, a latch lever that pivots a cam part on the top of the center post so that it can be raised, and a coil spring loaded into the center post. A bobbin for a sewing machine that has a slider that comes into elastic contact with the cam part by the action of a spring and restrains the latch lever in the raised or collapsed position, and holds the bobbin that is inserted into the center post when the latch lever is tilted. In the holding device, an adjustment screw is screwed onto the base of the center post so that the strength of the coil spring attached between the center post and the slider can be adjusted.

Here, the slider may have any structure or size as long as it can slide within the center post, but it is preferably in the shape of a cap so as to cover the coil spring. The thicker the slider is, the more stable the movement within the center post becomes, and the advantage is that the latch lever can be operated smoothly, but on the other hand, the force of the spring becomes stronger.
A large amount of force is required to operate the latch lever. The same applies when using a short coil spring or a coil spring with a large spring constant. In this regard, if the slider is made into a cap shape and placed over the spring, and a part or most of the cap is stored, the movement of the slider becomes stable, and a spring of appropriate length and strength can be used. It becomes possible to smoothly operate the latch lever without impairing the holding force of the bobbin.

The bobbin holding device according to the present invention can be applied not only to the bobbin case as before, but also to the inner pot by providing a recess and a center post so that the bobbin can be directly attached to the inner pot.

Function When the latch lever is raised or lowered, the slider sinks once against the action of the spring and then rises to maintain the latch lever in the raised or lowered state. In the former state, the bobbin is attached and detached, and in the latter state, the bobbin is held and prevented from flying out.

Turning in the adjustment screw shortens the distance between the slider and the spring pressure. Conversely, loosening the adjustment screw will weaken the spring pressure.

Embodiment In the embodiment shown in FIGS. 1 and 2, a coil spring 3 and a piece-shaped slider 4 are loaded in the center post 2 of a bobbin case 1, and an adjustment screw 5 screwed onto the bottom of the bobbin case is installed opposite to the slider 4. A spring 3 supported at the lower end biases the slider 4 upward and presses it against a cam portion 8 of a latch lever 7 which is pivotally supported by a pin 6 at the top of the post. 9 in the figure is a bobbin.

In the embodiment shown in FIG. 3, a coil spring 13 and a cap-shaped slider 14 that covers the spring are loaded inside the center post 12 of the bobbin case 11, and the slider 14 is operated by the action of the spring 13 as in the above embodiment. Cam part 1 of latch lever 15
6.

Effects of the invention As described above, the bobbin holding device of the present invention has a coil spring and a slider loaded in the center post, and the strength of the coil spring can be adjusted with an adjustment screw. It is extremely easy to manufacture compared to caulking a plate spring, and compared to devices that use conventional coil springs, it is possible to adjust the strength of the spring with an adjustment screw, which allows the coil springs to be more precise. is not required, reducing the manufacturing cost of the spring.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the bobbin case according to the present invention,
FIG. 2 is a plan view, FIG. 3 is a sectional view of another embodiment,
FIG. 4 is a sectional view of the conventional example, and FIG. 5 is a plan view thereof. 1... Bobbin case, 2... Center post,
3... Coil spring, 4... Slider, 5... Adjustment screw, 7... Latch lever, 8... Cam section, 1
1... Bobbin case, 12... Center post,
13...Coil spring, 14...Slider, 15
...Latch lever, 16...Cam section.

Claims (1)

[Claims for Utility Model Registration] (1) A center post 2 protruding from the bottom of the bobbin case 1 or the inner pot, a latch lever 7 with a cam part 8 pivoted to the upper part of the center post, and capable of being raised and folded; Due to the coil spring 3 loaded in the center post and the action of the spring 3, the cam portion 8
a slider 4 that comes into elastic contact with the latch lever 7 and restrains it in the raised position or the collapsed position;
In a bobbin holding device for a sewing machine that holds a bobbin inserted and attached to a center post 2 by tilting a latch lever 7, an adjustment screw 5 for clamping a coil spring 3 between a slider 4 and a center post base is screwed. A bobbin holding device characterized by: (2) The bobbin holding device according to claim 1, wherein the slider has a cap shape that covers the coil spring.