JPS6114374Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a full-rotation hook for a sewing machine, and in particular, to an outer hook that rotates in one direction around a horizontal axis, an inner hook supported in the outer hook, and an inner hook. This invention relates to a full-rotation hook having a bobbin that is directly removably attached to the hook.

Prior Art Conventionally, in this type of full-rotation hook, the bobbin thread wound around the bobbin was directly led out from the bobbin toward the inner hook fixing recess of the inner hook. On the other hand, in this full-rotation hook, a permanent magnet or a locking member biased by a spring was generally used to prevent the bobbin from coming off the inner hook. When taking into consideration things such as smooth thread delivery or application of appropriate tension to the bobbin thread, there is a certain limit to how much force can be applied to the bobbin. For this reason, depending on the type of bobbin thread, the bobbin thread itself may push the outer flange of the bobbin, causing the bobbin to come off the inner hook.

Further, in such conventional devices, the lower thread tension spring is fixed near the inner hook fixing recess, and is configured to apply tension to the lower thread led out to the inner hook fixing recess. Ta. On the other hand, it is well known that the bobbin thread wound around the bobbin is wound back and forth between flanges at both ends of the bobbin from one side to the other. When such a bobbin is attached to the inner hook and the bobbin thread is drawn out, there are cases in which the bobbin thread is drawn out from the flange side of the bobbin near the inner hook fixing recess, and cases where the bobbin thread is drawn out from the flange side far from the inner hook fixing recess. When the bobbin thread is drawn out, the amount of bending of the bobbin thread up to the bobbin thread tension spring is significantly different, and the tension ultimately applied to the bobbin thread changes greatly during sewing, which has a negative impact on the seams. There were problems such as the effects of

Purpose In this invention, in view of such circumstances, as a result of various studies, these defects have been eliminated by providing a bobbin thread T guide piece in the inner hook.

Embodiment An embodiment embodying the present invention will be described below.The needle 1 can pass through the needle hole 3 of the throat plate 2 and move up and down, and the needle 1 can move up and down through the needle hole 3 of the throat plate 2. A lower shaft 5 is rotatably supported around a horizontal axis in the bed of a sewing machine (not shown). Its lower axis 4
An outer hook 6 having a thread ring catching beak 5 is fixed to one end of the hook, and the outer hook 6 is rotated in one direction together with the lower shaft 4.

The inner hook 7 is rotatably supported in the outer hook 6 and has a hollow bobbin support shaft 8 in the center thereof. Further, at an upper position of the inner hook, a recess 9 for fixing the inner hook is adjacent to the vertical movement path of the needle 1.
is provided. The inner hook retaining recess 9 is fitted with a protrusion 11 of an inner hook retainer 10 fixed to the bed, thereby preventing the inner hook 7 from rotating together with the outer hook 6. Furthermore, the bobbin support shaft 8 has a through hole 1 extending in a direction perpendicular to the axis thereof and communicating with the center hole 12 of the bobbin support shaft 8.
3 is formed.

The bobbin 14 has a hollow shaft 15 inserted into the bobbin support shaft 8 of the inner hook 7 and a pair of flanges 16 and 17.
An annular groove 18 facing the through hole 13 is formed on the inner peripheral surface of the center hole 12 of the hollow shaft 15.

Further, a locking part body 19 is inserted and fitted into the center hole 12 of the bobbin support shaft 8, and the locking part body 19 is press-fitted into the center hole 12 and fixed to the shaft. a pair of leg portions 21 having different lengths extending from one end of the shaft portion 20 in the axial direction;
22, a protrusion 23 that is formed to protrude outward from the free end of the longer leg 22, passes through the through hole 13 of the bobbin support shaft 8, and protrudes into the annular groove 18 of the bobbin 14; and a locking protrusion 24 extending in the opposite direction, and are integrally formed from a synthetic resin material. Furthermore, in the center hole 12,
A leaf spring 25 bent into a U-shape is inserted and fitted together with the locking body 19, one end of which engages with the inner surface of the center hole 12, and the other end engages with the leg portion 22. The protrusion 23 is biased toward the through hole 13 by acting on the leg portion 22 thereof.
Of course, the pair of legs 2 of the locking body 19
1 and 22 are molded to be parallel when manufactured,
As shown in FIG. 2, when one leg 22 is inserted into the center hole 12, it is bent against its elasticity, so the leg 22 itself is bent in the direction of protruding toward the through hole 13. It has elastic return force. The locking protrusion 24 engages with the other end of the leaf spring 25 to prevent the leaf spring 25 from coming off the center hole 12.

The lower thread guide piece 26 has its base end attached to the inner circumferential wall 28 of the inner hook 7 by screws 27, 27, and forms the same arc as the inner circumferential wall 28, as is clear from FIG. As is clear from the figure, both flanges 16 and 17 of the bobbin 14 are located on one side of the bobbin 14.
A bobbin thread guide surface 29 is formed to face approximately the middle part between the bobbin 14 and the bobbin 14.
The lower thread 30 extending from the lower thread to the inner hook fixing recess 9 is guided so as to be led out through a substantially intermediate portion between the flanges 16 and 17. Also, the bobbin thread guide piece 2
In order to form an insertion gap for the bobbin thread 30 between the inner circumferential wall 28 and the bobbin thread guide piece 26, a notch 31 corresponding to the area indicated by A in FIG.
is formed.

2 and 4, an annular step 32 is formed on the flange 16 of the bobbin 14, and the tip 26a of the lower thread guide piece 26 extends close to the annular step 32.
In order to guide the lower thread 30 between the lower thread guide piece 26 and the notch 31, a recess 33 as shown in FIG.
4 is formed.

The flange 16 of the bobbin 14 is formed smaller than the flange 17 by the thickness of the lower thread guide piece 26. Further, 35 is a needle hole formed in the inner hook 7 through which the needle 1 passes.

As clearly shown in FIG. 5, a groove 36 having a flat surface 36a that is flush with the bottom wall 9a of the inner hook fixing recess 9 is formed on one side of the inner hook fixing recess 9. ing. Further, a positioning notch 37 is formed in the flange 33 of the inner hook 7, and the proximal end of a lower thread tension plate spring 39 is fixed to the positioning notch 37 by a screw 38. Leaf spring 3 for lower thread tension
The free end of 9 extends into the groove 36, and its tip is bent toward the front as shown in FIG. still,
The lower thread tension plate spring 39 is provided with a protrusion 40 for preventing the lower thread 30 from coming off.

Next, the effect will be explained.

First, the method for inserting the bobbin 14 will be described. All that is required is to pull out the bobbin thread 30 by the amount necessary to form a stitch at the start of sewing, and then insert the bobbin thread 30 into the bobbin support shaft 8 of the inner hook 7. As a result, the protrusion 23 of the locking member 19 urged by the leaf spring 25 projects into the annular groove 18 of the bobbin 14, and the bobbin 14 is prevented from coming off.

If sewing is started in this state, the needle thread loop formed as the needle 1 moves up and down is caught by the thread loop catching beak 5 of the outer hook 6 and then spread around the inner hook 7. . Thereafter, when the needle thread wheel is pulled up by the thread take-up lever, the bobbin thread 30 from the bobbin 14 is caught by the needle thread loop itself, and the bobbin thread guide piece 26
and the notch 31 (see FIG. 2), and further between the lower thread tension plate spring 39 and the flat surface 36a. After this, the stitches are formed continuously as in the conventional method.

As is clear from FIG. 2, when the bobbin thread 30 from the bobbin 14 is led out from the right side of the bobbin thread guide surface 29 of the bobbin thread guide piece 26, the bobbin 14 is The bobbin 14 receives a leftward acting force through the thread 30.
It never comes off. Also, the bobbin thread 30 is
4, both flanges 1 of the bobbin 14 are pulled out from either the left or right side.
Since the lower thread 3 is pulled out from approximately the middle of the threads 6 and 17, the tension applied to the lower thread 3 becomes uniform.

Effects As described in detail above, in the present invention, the bobbin thread guide piece 26 is attached to the inner circumferential wall 28 of the inner hook 7 so that the free end faces approximately the middle part between the flanges 16 and 17 of the bobbin 14.
Attach the bobbin thread 30 from the bobbin 14 to the inner hook fixing recess 9.
Since the bobbin thread 30 is guided so as to be guided out through a substantially middle portion of the bobbin thread 17, the bobbin 14 is periodically subjected to an acting force in the direction opposite to the direction in which the bobbin thread 30 is pulled out, and the bobbin thread 30 is pulled out from the inner hook. It's hard to deviate from 7. Moreover, since the bobbin thread 30 is led out through a substantially intermediate portion between both flanges 16 and 17 of the bobbin 14, no matter where the bobbin thread 30 is led out from the side closest to the flanges 16 and 17, the bobbin thread is always The tension applied to the seams 30 is approximately uniform, and beautiful seams can be formed.

[Brief explanation of the drawing]

FIG. 1 is a left side view, FIG. 2 is a cross-sectional view taken along the - line in FIG. 1, FIG. 3 is a front view of the inner hook 7 with the bobbin 14 removed, and FIG. 4 is a partial side view of the inner hook 7. , FIG. 5 is a partial top view of the inner hook 7, FIG. 6 is a perspective view of the lower thread guide piece 26, and FIG. 7 is a perspective view of the locking member 19 and the leaf spring 25. In the figure, 1 is a needle, 2 is a throat plate, 6 is an outer hook, 7 is an inner hook, 8 is a bobbin support shaft, 9 is a recess for fixing the inner hook, 1
0 is the inner hook stop, 12 is the center hole, 13 is the through hole, 1
4 is a bobbin, 15 is a hollow shaft, 16 and 17 are flanges, 18 is an annular groove, 19 is a locking part body, 20 is a shaft part, 21 and 22 are leg parts, 23 is a protrusion, 25 is a leaf spring 26 is a bottom 28 is an inner circumferential wall, 29 is a lower thread guide surface, 30 is a lower thread, 33 is a flange, 34 is a recessed portion, 36 is a groove portion, and 39 is a leaf spring for lower thread tension.

Claims (1)

[Claims for Utility Model Registration] An outer hook 6 that rotates in one direction around one axis, and an inner hook that is rotatably supported in the outer hook 6 and has a bobbin support shaft 8 in the center thereof. 7
By fitting the protrusion 11 of the inner hook stopper 10, which is formed above the inner hook 7 adjacent to the vertical movement passage of the needle 1 and placed in a stationary state, the inner hook 7 is moved to the outside. An inner hook fixing recess 9 that prevents the inner hook from rotating together with the hook 6; and a lower thread 30 provided on the inner hook 7 near the inner hook fixing recess 9 and guided to the inner hook fixing recess 9. Lower thread tension spring 3 for applying lower thread tension
9, a bobbin 14 consisting of a hollow shaft 15 inserted into the bobbin support shaft 8 of the inner hook 7, and a pair of flanges 16, 17; a bobbin 14 provided between the bobbin 14 and the inner hook 7; blocking means 19 and 25 for preventing the bobbin 14 from escaping; a proximal end portion thereof is attached to the inner peripheral wall 28 of the inner hook 7; and a free end thereof is attached to the bobbin support shaft 8 of the inner hook 7;
Both flanges 16, 17 of the bobbin 14 inserted into the
When the bobbin thread 30 wound around the bobbin 14 is led out toward the inner hook fixing recess 9, its free end engages with the bobbin thread 30 and A full-rotation hook for a sewing machine characterized by being provided with a bobbin thread guide piece 26 for bending a thread path.