JPH01160591A - Hook of sewing machine - Google Patents

Abstract

PURPOSE: To increase the quantity of a lower thread to be wound around a bobbin by inclining the axial line of the bobbin housed in an inner shuttle within one plane, which includes the rotary axial line of an outer shuttle and is vertical to the moving route of a needle, in respect to the rotary axial line of the outer shuttle. CONSTITUTION: A bobbin case 29 housing a bobbin 32 is mounted in a recess 31 of an inner shuttle 24. The bobbin 32 has a center hole 34 through which a stud 35 is inserted. The stud 35 erected on a bottom 31a of the housing recess 31 of the inner shuttle 24 is inserted through that center hole 34. The axial line of the stud 35, namely, a rotary axial line 12 of the bobbin 12 is inclined at an angle θto a rotary axial line 11 of an outer shuttle 18 and determined so that the top end of a needle 41 can not collide with a flange 39 when the needle 41 is moved up and down along with its moving route. It is enough for the bottom 44 of the inner shuttle 24 to have a little gap (d) just for passing the outer shuttle 18 and an upper thread at a first upper side terminal part 44a of that bottom 44. Thus, useless spaces can be utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sewing machine hook that can be suitably implemented in a sewing machine or the like.

Conventional technology FIG. 3 is a typical prior art cross-sectional view.

For example, an outer hook 1 of a vertical full-rotation hook supports an inner hook 2, and a bobbin gear 5 shown by an imaginary line for storing a bobbin 4 on which a bobbin thread 3 is wound is supported on the inner hook 2. is installed. The outer hook 1 is fixed to a horizontal lower shaft 6 and driven to rotate. The needle 7 moves up and down reciprocally as indicated by the arrow 8, and the lowest point in the path of movement of the needle 7 is indicated by the reference numeral 9. The rotational axis of the bobbin 4 is on a straight line with the axis of the lower shaft 6, or is parallel to it. In such a vertical full-rotation hook, a rail 10 formed on the outer peripheral surface of the inner hook 2 fits into a rail groove 11 formed on the outer hook 1. The upper thread loop is caught by the tip 16 and the outer hook 1
As the thread rotates, the thread passes through the thread while contacting the lower part of the bottom 14 of the inner pot 2, and slides on the bottom 14 of the inner pot 2.

Problems to be Solved by the Invention In such prior art, in order to increase the amount of bobbin thread wound around the bobbin 4, (a) increasing the outer diameter of the bobbin 4, and (b) increasing the amount of bobbin thread wound around the bobbin 4, It is necessary to make one of the changes such as increasing the length H in the axial direction of No. 4.

(a) When the outer diameter of the bobbin 4 is increased, the diameters of the raceways 11 of the outer hook 1 and the rails 10 of the inner hook 2 are increased. Therefore, even if the rotational speed of the outer hook 1 is constant, the raceway 1
The circumferential speed of 1 increases. Therefore, the frictional force between the rail groove 11 and the rail 10 increases.

As a result, the amount of heat generated increases.

Furthermore, as a result of the increased frictional force, the upper thread passes through the contact area between the hook locking recess 15 of the inner hook 2 and the hook locking member (not shown) that engages with this hook locking recess 15. When doing so, a large tension is created in the upper thread.

As a result, thread alignment becomes poor, and thread balls or towel marks are more likely to occur.

(b) To increase the length H of the bobbin 4 in the axial direction, (bl) move the bobbin 4 toward the open end of the inner pot 2 (
(b2) The bottom 14 of the inner pot 2 is enlarged to the left in FIG.
Two ways (bl) and (b2) of extending to the 4th side are assumed.

When the above-mentioned (bl) configuration is adopted in which the bobbin 4 is extended toward the open end side of the inner pot 2, when the needle 7 moves up and down, at the lowest point 9, the bobbin thread 3 wound around the bobbin 4 is removed. Therefore, the needle 7 pierces the bobbin thread 3 wound around the bobbin 4, and thereby the needle 7
The bobbin thread 3 wound around the thread breaks.

If the above-described (b2) configuration is such that the bottom 14 of the inner hook 2 is extended to the left in FIG. 3, the upper thread will get caught in the lower part of the bottom 14 of the inner hook 2, making it impossible to thread the thread. This makes sewing impossible.

The object of the present invention is that in the prior art shown in FIG.
The above-mentioned problem caused by enlarging the outer diameter of the bobbin 4 or lengthening the length H of the bobbin 4 can be solved, and the amount of bobbin thread wound around the bobbin 4 can be increased. The aim is to provide sewing machine hooks.

Means for Solving the Problems The present invention provides for aligning the axis of the bobbin housed in the inner hook with respect to the rotation axis of the outer hook within a plane that includes the rotation axis of the outer hook and is perpendicular to the movement path of the needle. There is a sewing machine head that is characterized by being tilted.

A preferred embodiment is characterized in that the axis of the bobbin is inclined so that a portion of the bobbin near the needle movement path moves away from the needle movement path.

According to the present invention, the bobbin is arranged within a plane including the rotational axis of the outer hook perpendicular to the needle movement path, with its axis and line inclined with respect to the rotational axis of the outer hook. , the length of the bobbin in the axial direction can be increased. As a result, the amount of winding of the bobbin thread around the bobbin can be increased, and therefore the amount of sewing that can be performed with one bobbin can be increased. Furthermore, when the bobbin thread wound around the bobbin is used up, it is possible to reduce the number of times the bobbin is replaced with a bobbin wound with a new bobbin thread, thereby improving work efficiency.

Embodiment FIG. 1 is a cross-sectional view of a rotary hook 17 according to an embodiment of the present invention, taken along an imaginary plane perpendicular to the moving path of the needle 41. In the vertical full-rotation hook 17 provided in the lockstitch sewing machine, the outer hook 18 includes an outer hook body 19 and a mounting member 20, and the mounting member 2o is fixed to a lower shaft 21 having a horizontal rotation axis. An inner hook holder 22 is fixed to the outer hook main body 19, and a track groove 23 is thus formed. This track groove 23 is connected to the lower shaft 2
1, therefore, it is formed to extend in the circumferential direction within a virtual plane perpendicular to the rotation axis 11 of the outer hook 18. A rail 25 is formed on the outer periphery of the inner hook 24, and the rail 25 fits into the rail groove 23 and is supported by the outer hook 18. A protrusion of a retaining member (not shown) fixed to the body of the sewing machine or the like fits into the anti-rotation recess formed in the inner hook 24, and the inner hook 2
Lock the rotation of step 4.

A bobbin case 29 containing a bobbin 32 is attached to the recess 31 of the inner hook 24. The bobbin 32 is the stud 3
A right cylindrical body 38 having a central hole 34 through which the cylindrical tube 5 is inserted, and a pair of flanges 3 fixed to both ends of the cylindrical body 38.
9.40.

A bobbin thread 33 is wound around the bobbin 32, and a stud 35 erected at the bottom 31a of the storage recess 31 of the inner hook 24 is inserted into the center hole 34 of the bobbin 32.

The axis of the stud 35 and therefore the axis of rotation of the bobbin 32 &
! 12 is inclined at an angle θ with respect to the rotational axis 11 of the outer hook 18. This angle θ is, for example, 3 to 10 degrees, and is determined so that the tip of the needle 41 does not collide with the flange 39 when the needle 41 moves up and down along its movement path. Further, the bobbin 32 is arranged so that its rotational axis 12 forms a straight line common to the axis of the inner pot 24.

The bottom 44 of the inner pot 24 is generally flat;
It is sufficient that the first upper end 44a of No. 4 has a small gap d that allows the outer hook 18 and the upper thread to pass through. Therefore, as shown in FIG. 3 of the prior art, a relatively large gap d1 can be used to make use of wasted space.

In another embodiment, the lower end 4 of FIG.
4b to the mounting member 20 with a gap d.
Accordingly, the axis of rotation 11 of the bobbin 32 may be inclined with respect to the axis of rotation 12 of the outer hook 18 so as to form an angle θ1 in a direction opposite to the direction of inclination shown in FIG.

FIG. 2 shows a vertical full rotation hook 1 showing another embodiment of the present invention.
FIG. 7a is a longitudinal cross-sectional view of FIG. Note that the same reference numerals are given to parts corresponding to those in the above-described embodiment.

In the embodiment described above, the axis of rotation 12 of the bobbin 32 is aligned with the needle 4.
Although the bobbin 32 is arranged at an angle θ1 with respect to the rotation axis 11 of the outer hook 18 in a virtual plane perpendicular to the movement path of the needle 41, in this embodiment, the bobbin 32 is also arranged in a virtual plane perpendicular to the movement path of the needle 41. Within a virtual plane that includes the rotational axis g1 of the outer hook 18, the axis 12 is moved at an angle θ2 so as to be far away from the needle 41.
It is placed at an angle. The needle 41 moves up and down, and the lowest point of the needle 41 in its path of movement is indicated by reference numeral 43. This angle θ1 is determined so as to avoid the moving path of the needle 41 and to prevent the needle 41 from colliding with the flange 39 at the lowest point 43 of the needle 41.

This angle θl is, for example, 3 to 10 degrees. As a result, in the prior art described in FIG.
However, in this embodiment, the flange 39 of the hebobin 32 on the open end side of the inner pot 24 can be exposed below the lowest point 43 regardless of the moving path of the needle 41. Can be done. Moreover, the inner pot 24
The bottom 44 has an upper end 44c located on the proximal end side of the outer hook 18 (
It has a bulging shape (left side in Figure 2).

Therefore, the upper thread smoothly slides and moves on the bottom 44, and the upper thread does not get caught near the lower end 44d of the bottom 44, making it possible to thread the thread reliably.

Thus, according to the present invention, the rotation axis 12 of the bobbin 32
is at an angle θ1. with respect to the rotational axis 11 of the outer hook 18. By tilting by θ2, the length of the bobbin 32, that is, the length in the axial direction of the cylinder 38 on which the flanges 39 and 40 are connected and the bobbin thread 33 is wound, can be increased. In addition, the outer hook 18 may be of a conventional configuration, and the inner hook 24 can be increased.
The bobbin 32 and bobbin case 29 may be replaced in an existing sewing machine. This achieves the excellent effect of making it possible to significantly increase the amount of winding of the bobbin thread 33. Furthermore, as described above, the inner hook 24, bobbin 32, and bobbin case 29 according to the present invention are attached to the outer hook 18 of a conventional sewing machine, and the bobbin thread 32 of the bobbin 32 is attached to the outer hook 18 of a conventional sewing machine.
When the amount of winding is increased, there is an advantage that there is no need to change the amount of needle thread taken out of the thread take-up of the sewing machine. This also allows the invention to be easily implemented in conjunction with existing sewing machines.

As a further embodiment, although the hook 17a in the above embodiment has a full vertical rotation, it may also have a horizontal full rotation, and the present invention is also suitably implemented for a half rotation hook. be able to.

Effects As described above, according to the present invention, the axis of the bobbin is arranged in a plane perpendicular to the movement path of the needle and inclined with respect to the axis of rotation of the outer hook. The axial length of the bobbin can be increased by making use of the wasted space between the bobbin and the bobbin, thereby increasing the amount of winding of the bobbin thread. Furthermore, according to the present invention, a conventional outer hook can be used, and the payout amount of the balance can be the same as before.
Since it is only necessary to replace at least the inner bobbin and the bobbin, an excellent effect is achieved in that it can be widely implemented in conjunction with existing sewing machines.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rotary hook 17 according to an embodiment of the present invention taken along an imaginary plane perpendicular to the moving path of the needle 41, FIG. 2 is a longitudinal cross-sectional view of another embodiment of the present invention, and FIG. 1 is a cross-sectional view showing a typical prior art; FIG. 17.17a...Vertical full rotation, 18...Outer hook, 19...Outer hook body, 20...Mounting member, 21.
・・Lower shaft, 23・Race groove, 24・Inner pot, 25・
...rail, 26...sword tip, 29...bobbin' gear,
32...Bobbin, 33...Bobbin thread, 41...Needle, 1
1...Rotation axis of the outer hook 18, 12...Rotation axis of the bobbin Agent Patent attorney Keiichi Saikyo Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A sewing machine characterized in that the axis of the bobbin housed in the inner hook is inclined with respect to the rotational axis of the outer hook within a plane that includes the rotational axis of the outer hook and is perpendicular to the movement path of the needle. Kama. (2) The sewing machine according to claim 1, wherein the axis of the bobbin is inclined so that a portion of the bobbin near the needle movement path is moved away from the needle movement path. Ma.