JPS633672Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a rotation noise prevention device for a full-rotation hook of a sewing machine.

The full-rotation hook of a conventional sewing machine has an outer hook that has a tip for scooping up the upper thread loop, and a track groove on the inner circumferential surface that fits into the track of the inner hook that stores the bobbin thread. The hook is rotatably fitted, an inner hook track band is interposed by an inner hook holder to prevent the inner hook from falling off, and a thread dividing spring is provided on the outer periphery of the outer hook to cover a part of the sword tip,
The outer hook is inserted into the drive shaft, and the inner hook is engaged in a predetermined position with a hook stopper so that it does not rotate at the same time as the outer hook rotates. However, the rotating and sliding parts of the outer hook and inner hook are The inner hook notch is formed around the needle drop and is engaged upward, so that when the outer hook is rotated, the inner hook notch is formed around the needle drop. The inlet collides with the upper thread loop hooking portion of the track notch of the inner hook due to fitting play, which obstructs smooth rotation of the outer hook and generates noise. As a countermeasure to this problem, play in the fit between the outer hook track groove and the inner hook track band can be reduced.
Measures have been taken to improve accuracy within 0.02 m/m, and collision noise has been greatly reduced, but too little play will cause seizure, and with a fitting tolerance of 0.01 m/m, there will be cost problems.

This idea was made in view of this point, and the fitting of the rotating sliding part of the outer pot and inner pot is 0.02~
The tolerance has a play of 0.05m/m, which eliminates the play when the tip of the rail groove entrance fits into the inner hook track thread hook when the outer hook rotates, smoothing the rotation of the outer hook and reducing contact collision noise. The object of the present invention is to provide a full-rotation hook device for a sewing machine that prevents the above problems.

An embodiment of this invention will be described below based on the drawings. 1 is an outer pot, and a boss 3 is provided with a shaft hole 2.
A tip 4 (not shown) for scooping up a needle thread loop is formed at one end of the bowl-shaped opening, which is partially cut out, and a flat inner hook holding surface 5 (not shown) is formed at the other end, and its inner peripheral surface is not shown. A track groove 8 is provided to fit a partially cut out annular track 7 provided on the outer periphery of the inner hook 6 for storing the bobbin thread, and the inner hook 6 is rotatably fitted thereinto.
The outer hook of a full-rotation hook is screwed onto the outer hook 1 with the inner hook track band 7 interposed therebetween, and a thread separation spring 11 that covers a part of the tip 4 is screwed onto the outer peripheral surface 10 on the tip side. 1, a semicircular notch groove 14 forming a window 13 penetrating from the outer circumferential surface 12 to the rail groove 8 is cut near the notched end of the outer circumferential surface 12 of the inner hook holding surface 5, and the semicircular notch A screw hole 16 is provided in one end surface of the plurality of curved walls 15 formed by the grooves 14, and an elastic piece 17 formed with a curved surface symmetrical to the semicircular curved surface of the semicircular notched groove 14 is inserted into the curved surface with one free end. The inner hook 6 is rotatably fitted into the raceway groove 8 with a part slightly protruding from the raceway groove 8, and is screwed onto the curved wall 15 so as to be biased toward the outer peripheral surface 7' of the raceway 7. be.

With this configuration, even if there is a play of 0.05 m/m between the outer hook 1, the track groove 8, the inner hook 6, and the track 7,
The point at which the track groove inlet 18 of the outer hook tip 4 and the track hooking part 19 of the inner hook 6 come into contact is the elastic piece provided on the curved wall 15 of the outer circumferential surface 12 of the outer hook 1 and the inner hook holding surface 5 described above. 17, the track 7 of the inner hook 6 is pressed in the direction of the track groove entrance 18, and the fitting is inserted with zero play, so a collision is avoided, and the outer hook rotates smoothly, noise is prevented, and the movement is smooth. This has the effect that beautiful seams can be easily obtained by rotation.

Although the embodiment is described with respect to a vertical full-rotation hook, a horizontal full-rotation hook provided with an inner hook holder with an intervening inner hook track band has the same effect.

[Brief explanation of drawings]

The drawing shows one embodiment of this invention.
The figure is an exploded perspective view of a full-rotation hook with a thread separation spring screwed onto the outer hook. Figure 2 is an enlarged partially cutaway plan view of the same outer pot as above. Figure 3 is its side view. FIG. 4 is a partially enlarged view of the semicircular notch groove shown in FIG. 3 with the elastic piece removed. 1: Outer pot, 6: Inner pot, 7: Track track, 8: Track groove, 1
2: Outer peripheral surface, 13: Window, 14: Semicircular notch groove, 1
5: Curved wall, 17: Elastic piece, 18: Track entrance, 1
9: Track latching part.

Claims (1)

[Scope of utility model registration request] A sword tip is formed at one end of the bowl-shaped opening, which is partially cut out, and a flat inner pot holding surface is formed at the other end, and an annular track with a partially cut out part of the inner pot is formed on its inner peripheral surface. A semicircular notch groove is cut into the outer hook provided with the fitting raceway groove near the notched end portion of the outer circumferential surface of the inner hook holding surface to form a window penetrating from the outer circumferential surface to the raceway groove. A screw hole is provided in one end surface of the plurality of curved walls formed by the semicircular notched grooves, and an elastic piece formed with a curved surface symmetrical to the semicircular curved surface of the semicircular notched groove is attached to one end of the curved surface with one free end. 1. A full-rotation hook device for a sewing machine, characterized in that a portion of the hook slightly protrudes into a raceway and is screwed onto a curved wall so as to bias it against the outer peripheral surface of an inner hook raceway that is rotatably fitted into the raceway.