JPH0255071B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a bobbin case that can be suitably implemented in a lockstitch sewing machine.

Prior Art A typical prior art is shown in FIG.
An inner hook 2 is supported by an outer hook 1 of the vertical full-rotation hook, and a bobbin case 5 shown by an imaginary line for storing a bobbin 4 on which a bobbin thread 3 is wound is attached to the inner hook 2. It will be installed. The outer hook 1 is fixed to a horizontal rotating shaft 6 and driven to rotate. The needle 7 moves back and forth up and down 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 rotation axis of the bobbin 4 and the rotation axis of the rotation shaft 6 are on a straight line.

FIG. 9 is a sectional view of the outer hook 1 in which the inner hook 2 is housed. Rail 1 formed on the outer peripheral surface of the inner hook 2
0 fits into a track groove 11 formed on the outer hook 1.

The loop 13 of the upper thread 12 is caught by the tip 16, and as the outer hook 1 rotates, the state shown in FIG. 10 1 changes to the state shown in FIG. The thread is passed through while contacting the lower part 14a of the bottom 14, and then the thread is slid on the bottom 14 of the inner hook 2 as shown in FIG. 10.

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 D of the bobbin 4, and (b) increasing the amount of bobbin thread wound around the bobbin 4, It is necessary to make some change, such as increasing the length H in the axial direction.

(a) When the outer diameter D of bobbin 4 is increased, outer hook 1
The diameters of the raceway 11 of the inner rotor 2 and the raceway 10 of the inner rotor 2 become larger. Therefore, even if the rotational speed of the outer hook 1 is constant, the circumferential speed of the raceway groove 11 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 increase in frictional force, the upper thread 12 is pushed between the hook locking recess 15 of the inner hook 2 and this hook locking recess 15.
Upper thread 1
2, a large tension is created in the upper thread 12. As a result, thread tightness deteriorates, and thread balls or towel marks are more likely to occur.

(b) In increasing the length H of the bobbin 4 in the axial direction, (b1) extending the bobbin 4 toward the open end side of the inner hook 2 (to the right in Fig. 8), and (b2 ) Two methods (b1) and (b2) are envisaged: enlarging the bottom 14 of the inner hook 2 to the left in FIG. 8 and extending the bobbin 4 toward the bottom 14.

When the above-mentioned (b1) configuration is adopted in which the bobbin 4 is extended toward the open end side of the inner hook 2, the needle tip at the lowest point 9 moves upward and downward when the needle 7 moves up and down. The needle 7 descends toward the inner diameter side than the outer diameter side, so that the needle 7 lowers the bobbin thread 3 wound around the bobbin 4.
This causes the bobbin thread 3 wound around the bobbin 4 to break.

When the above-mentioned (b2) bottom 14 of the inner hook 2 is configured to extend to the left in FIG. 8, the conventional bottom shown by the imaginary line 17 in FIG. 11 extends to the left in FIG. It becomes the shape. Therefore, the upper thread 12 gets caught on the lower part 14a of the bottom 14 of the inner hook 2, making it impossible to pass the thread through. This makes sewing impossible.

The object of the present invention is to enlarge the outer diameter D of the bobbin 4 in the prior art shown in FIGS. 8 to 10,
Another object of the present invention is to provide a bobbin case that solves the above-mentioned problems caused by increasing the length H of the bobbin 4 and can increase the amount of bobbin thread wound around the bobbin. .

Means for Solving the Problems The present invention provides a bobbin case that is installed in an inner hook with the bobbin stored in a bobbin storage space, in which the axis of the bobbin storage space is the lowest point of the needle. This bobbin case is characterized by being inclined at an angle of 91 degrees or more and 135 degrees or less with respect to the direction of reciprocating movement of the needle.

Effect According to the present invention, in the bobbin case that is installed in the inner hook with the bobbin stored therein, the axis of the bobbin intersects the reciprocating direction of the needle at an angle of 91 degrees or more and 135 degrees or less. configured to do so. This allows the outer diameter of the bobbin to be increased and/or the length of the bobbin in the axial direction to be increased. This makes it possible to increase the amount of bobbin thread on the bobbin. At this time, there is no need to increase the outer diameter of the inner hook that houses the bobbin, so the outer hook can remain in its existing configuration, and the amount of needle thread taken out of the thread take-up can remain the same as before. There is no need to change the amount of feed. Therefore, as described in relation to the prior art, problems such as increased heat generation, poor thread tightness, thread breakage, and difficulty in threading the upper thread occur. , does not occur in the present invention.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention.
For example, a lockstitch sewing machine has a vertical full-rotation hook 20.
is provided. The outer hook 21 of the vertical full-rotation hook 20 includes an outer hook body 22 and a mounting member 23, and the mounting member 23 is fixed to a rotation shaft 24 that is rotationally driven around a horizontal rotation axis. An inner hook holder 25 is fixed to the outer hook body 22, and a track groove 26 is thus formed. The track groove 26 is formed to extend in the circumferential direction on the inner circumferential surface of the outer hook body 22 within a virtual plane perpendicular to the rotation axis 24 and therefore to the rotation axis l1 of the outer hook 21.

A rail 28 is formed on the outer peripheral surface of the inner hook 27,
This rail 28 fits into the rail groove 26 and is supported by the outer hook 21. This inner hook 27 has a detent recess 2
9 is formed, and a protrusion of a hook stopper member (not shown) fixed to the body of the sewing machine is fitted into the rotation prevention recess 29 to prevent rotation of the inner hook when the outer hook 21 rotates. is locked. A bobbin case 30 is attached to the inner hook 27.
A bobbin 31 is housed in. This bobbin case 30 is housed and locked in the inner hook 27 by a structure not shown. The axis l5 of the bobbin 31 intersects the extension line l6 of the reciprocating path of the needle 50 at an angle of 91 degrees or more and 135 degrees or less, preferably at an angle θ of 91 degrees or more and 120 degrees or less. ing.

FIG. 2 is a sectional view taken along a plane including the axis l2 of the inner hook 27, and FIG. 3 is a front view of the inner hook 27. The inner hook 27 includes a generally right cylindrical cylindrical portion 35 on which a rail 28 is formed, and a bottom portion 36.
and has. The outer circumferential surface 37 of the cylindrical portion 35 has an outer diameter D1 that is slightly smaller than the inner diameter of the outer hook main body 22.
Further, the inner circumferential surface 38 of the cylindrical portion 35 has an inner diameter D2 smaller than the outer diameter D1 of the outer circumferential surface 37. The outer circumferential surface 37 and the inner circumferential surface 38 have a common inner pot 27.
, and the axis l2 is parallel to the rotational axis l1 of the outer hook 21. Also, the bottom part 36 is the inner pot 2
It is formed at an angle θ1 other than a right angle with respect to the axis l2 of 7.

FIG. 4 is a sectional view of the bobbin case 30 taken along a plane including axes l3 and l4, and FIG. 5 is a front view of the bobbin case 30. Bobbin case 3
0 has a cylindrical portion 40 and a bottom portion 41, and the outer circumferential surface 42 of the cylindrical portion 40 is the inner diameter of the inner circumferential surface 38 of the inner pot 27.
It has an outer diameter D3 that is slightly smaller than D2. Also, the cylindrical part 4
The inner circumferential surface 43 of 0 has an inner diameter D4 smaller than the outer diameter D3 of the outer circumferential surface 42. The axis l3 of the outer circumferential surface 42 and the axis l4 of the inner circumferential surface 43 form an angle θ2.

A bobbin 31 shown in FIG. 6 is housed in such a bobbin case 30. This bobbin 31
The winding trunk 45 around which the bobbin thread is wound, and the winding trunk 4
A pair of flanges 46a fixed to both ends of 5,
46b. The axis l5 of the bobbin 31 is parallel to the axis l4 of the bobbin case 30 when it is housed in the bobbin case 30, and therefore the axis l5 of the bobbin 31 is parallel to the axis l4 of the bobbin case 30.
It is housed at an angle θ2 with the axis l3 of. Moreover, the axis l3 of the outer peripheral surface 42 of the bobbin case 30 is
The inner hook 27 is parallel to the axis l2 of the inner hook 27 shown in FIG. 2, and therefore the inner hook 27 is housed in the outer hook 21 shown in FIG.
When the bobbin case 30 containing the bobbin case 30 is mounted, the rotational axis l1 of the outer hook 21, the axis l2 of the inner hook 27, and the axis l3 of the outer peripheral surface 42 of the bobbin case 30 form a common straight line. Further, at this time, the axis l5 of the bobbin 31 and the axis l4 of the inner peripheral surface 43 of the bobbin case 30 form a common straight line.

In this way, the axis l of the bobbin 31 is placed inside the inner hook 27.
By storing the bobbin 31 at an angle with respect to the rotational axis l1 of the outer hook 21, the length H1 of the bobbin 31 in the axis l5 direction is _reduced compared to the length H in the axial direction of the bobbin 4 of the prior art. can be increased.
Further, the outer diameter D ₅ of the bobbin 31 can be made larger than the outer diameter D of the bobbin 4 of the prior art. This makes it possible to increase the amount of winding of the bobbin thread around the bobbin 31.

Effects of the Invention According to the present invention, since the axis of the bobbin intersects the reciprocating direction of the needle at an angle of 91 degrees or more and 135 degrees or less, the outer diameter of the bobbin can be reduced compared to the prior art. In addition, it becomes possible to increase the length of the bobbin in the axial direction. Therefore, the amount of winding of the F yarn wound around the bobbin can be increased, the number of times the bobbin must be replaced during sewing can be reduced, and the efficiency of sewing work can be improved. In addition, the bobbin case in which such a bobbin is stored may be formed so that the axis of its inner circumferential surface is inclined with respect to the axis of its outer circumferential surface. It can be stored easily, manufactured easily, and production efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, FIG. 2 is a sectional view taken along a plane including the axis l2 of the inner hook 27, FIG. 3 is a front view of the inner hook 27, and FIG. 4 is a bobbin. 5 is a front view of the bobbin case 30, FIG. 6 is a side view of the bobbin 31, FIG. 7 is a sectional view of the outer hook 21, and FIG. FIG. 8 is a sectional view of a typical prior art, FIG. 9 is a side view thereof, FIG. 10 is a side view of the inner pot 2 for explaining the operation of the prior art, and FIG. 11 is a diagram explaining the problems of the prior art. It is a side view of the inner pot 2 for explanation. 20...Vertical full rotation hook, 21...Outer hook, 2
4... Rotating shaft, 26... Track groove, 27... Inner hook,
28...Rail, 30...Bobbin case, 31...
Bobbin, 42...Outer peripheral surface of bobbin case 30, 4
3... Inner peripheral surface of bobbin case 30, 50... Needle,
l1...Axis of rotation of the outer hook 21, l2...Axis of the inner hook 27, l3...Axis of the outer circumferential surface 42 of the bobbin case 30, l4...Axis of the inner circumferential surface 43 of the bobbin case 30, l5...Bobbin 31 axis, l6...
...An extension of the moving path of the needle 50.

Claims (1)

[Scope of Claims] 1. In a bobbin case that is installed in an inner hook with the bobbin stored in a bobbin storage space for storing the bobbin, the axis of the bobbin storage space is set so as to avoid the lowest point of the needle. A bobbin case characterized by being inclined at an angle of 91 degrees or more and 135 degrees or less with respect to the reciprocating direction of the needle.