JPH0311798B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications The present invention relates to a lockstitch sewing machine for sewing.

Prior Art FIG. 5 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 the inner hook 2 has a bobbin case 5 indicated by an imaginary line for storing a bobbin 4 on which a bobbin thread 3 is wound. is installed. The outer hook 1 is fixed to a horizontal lower shaft 6 and driven to rotate. needle 7
moves up and down reciprocally as shown by arrow 8, and the needle 7
The lowest point on the path of travel is indicated by 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. Needle thread loop has tip 16
As the outer hook 1 rotates, the thread passes through the thread while contacting the lower part of the bottom 14 of the inner hook 2, and slides on the bottom 14 of the inner hook 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, it is necessary to increase the length H of the bobbin 4 in the axial direction.

When increasing the length H of the bobbin 4 in the axial direction, (a) move the bobbin 4 toward the open end of the inner hook 2 (the fifth
(b) The bottom 14 of the inner hook 2 is enlarged to the left in FIG.
Two ways (a) and (b) are assumed: extending to the 4th side.

When the above-mentioned (a) 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 than the outer diameter, so that the needle 7 pierces the lower thread 3 wound around the bobbin 4, thereby causing the lower thread 3 wound around the bobbin 4 to break.

If the above-mentioned (b) structure is such that the bottom 14 of the inner hook 2 is extended to the left in FIG. 5, the upper thread will get caught on the lower part of the bottom 14 of the inner hook 2, making it impossible to thread the thread. . This makes sewing impossible.

An object of the present invention is to solve the above-mentioned problem caused by increasing the length H of the bobbin 4 in the prior art shown in FIG. It is an object of the present invention to provide a sewing machine which can be increased in size.

Means for Solving the Problems In the present invention, a hook 30 is provided that houses a bobbin 61 on which a bobbin thread 68 is wound around a lower shaft 28 having a horizontal axis l2. The axis l3 of the needle 38, which is synchronously driven in approaching/separating displacement, is aligned with the lower axis 28.
The sewing machine is characterized in that the sewing machine is inclined with respect to a virtual plane perpendicular to the axis l2.

Effect According to the present invention, the axis l3 of the needle 30 is aligned with the lower axis 2
According to the amount of inclination of the axis l3 of the needle 38, the needle 38 moves away from the hook 30 in the axial direction from the lowest position closest to the hook 30. can be done.
As a result, the bobbin 61 is stored in the rotary hook 30.
The length of the bobbin 61 in the direction of the axis l2 can be increased in accordance with the separated distance, and therefore the amount of winding of the bobbin thread on the bobbin 61 can be increased. At this time,
The amount of needle thread taken out of the thread take-up can be left as it is.
There is no need to change the amount of feed. Therefore, as described in connection with the prior art described above, the problems of thread breakage and difficulty in threading the upper thread do not occur in the present invention.

Embodiment FIG. 1 is a perspective view of a sewing machine 20 according to an embodiment of the present invention, and FIG. 2 is a sectional view of a vertical full-rotation hook 30 provided in the sewing machine 20. The sewing machine 20 is
It includes a horizontal bed 21 and a main body 22 provided on the bed 21. The main body 22 is provided with an upper shaft 23 that is rotationally driven around the horizontal axis l1. A bevel gear 24 is fixed to the upper shaft 23, and a bevel gear 26 fixed to one end of an interlocking shaft 25 that is rotationally driven around a vertical axis is engaged with the bevel gear 24. A bevel gear 27 is fixed to the other end of the interlocking shaft 25, and a bevel gear 29 fixed to one end of the lower shaft 28 is engaged with the bevel gear 27.

The lower shaft 28 is rotationally driven around a rotation axis l2 that is parallel to the rotation axis l1 within a vertical plane that includes the rotation axis l1 of the upper shaft 23. A vertical full-rotation hook 30 is attached to the other end of the lower shaft 28.

Further, a flywheel 32 having a V-groove 31 formed on the outer circumference is attached to one end of the upper shaft 23, and a balance cam 33 is attached to the other end. This balance cam 33 has a balance link 34 and a crankshaft 35 attached coaxially with the balance link 34.
and is provided. The balance link 34 is connected to the balance 3
6 to reciprocate the balance 36 up and down.

One end of a connecting rod 37 is attached to the crankshaft 35, and a needle bar 39 to which a needle 38 is detachably attached is fixed to the other end. This needle bar 39 is inserted into an insertion hole 41 of a guide member 40 fixed to the main body 22. The axis l3 of the needle 38 is within a plane including the rotational axes l1 and l2 of the upper shaft 23 and the lower shaft 28, and with respect to the vertical line l4 which is in a virtual plane perpendicular to the rotational axis l2 of the lower shaft 28. and is inclined at an angle θ1. This angle θ1 is selected, for example, from 3 to 10 degrees.

The flywheel 32 is rotationally driven by a V-belt 44 extending from a drive source (not shown) and wound around the V-groove 31. When the flywheel 32 is rotationally driven,
The upper shaft 23 is driven to rotate around its rotation axis l1, and the balance 36 and the needle 38 are driven to reciprocate up and down. The rotation of the upper shaft 23 is transmitted to the lower shaft 28 via the interlocking shaft 25, and the lower shaft 28 is rotationally driven around its rotation axis l2. In such a sewing machine 20, the upper shaft 23 and the lower shaft 28 have parallel axes within one vertical plane, and the needle 38 moves along the vertical line l so as to escape from the bobbin 61, which will be described later.
It is reciprocated up and down while being inclined by an angle θ1 with respect to 4.

In the full-rotation hook 30 provided in such a sewing machine 20, the outer hook 50 has an outer hook main body 51.
and a mounting member 52, the mounting member 52 being fixed to the lower shaft 28 having a horizontal axis of rotation.
An inner hook holder 53 is fixed to the outer hook body 51, and thus a track groove 54 is formed. This track groove 5
4 is formed to extend in the circumferential direction within a virtual plane perpendicular to the rotation axis l2 of the lower shaft 28. A rail 56 is formed on the outer periphery of the inner hook 55, and the rail 56 fits into the rail groove 54 and is supported by the outer hook 50. The outer hook 50 further includes a tip 57 and a spring 58. A protrusion of a hook stopper (not shown) fixed to the body of the sewing machine is fitted into a rotation prevention recess 59 formed in the inner hook 55, so that the outer hook 50 is fixed to the lower shaft 2.
Rotation of the inner hook 55 is stopped by the inner hook 55, which is driven to rotate around the rotation axis l2 of the inner hook 55.

A bobbin case 62 containing a bobbin 61 is attached to the recess 60 of the inner hook 55. bobbin 61
has a right cylindrical body 65 having a central hole 64 through which the stud 63 is inserted, and a pair of flanges 66, 67 fixed to both ends of the cylinder 65. A bobbin thread 68 is wound around such a bobbin 61, and a stud 63 erected from the bottom 69 of the inner hook 55 is inserted through the center hole 64. stud 63
, and therefore the rotational axis of the bobbin 55 is coaxial with the rotational axis l2 of the lower shaft 28. needle 3
8 moves up and down reciprocally in the direction of arrow 70, and the lowest point of needle 38 in its path of movement is indicated by reference 71. The lowest point 71 of such a needle 38 is the lowest point 71 of the needle 38.
8 is determined so as not to collide with the lunge 67.

Referring to FIG. 3, a distal end portion 80 of the tip 57 formed on the outer hook 50 has an end surface 81 parallel to the movement path of the reciprocating up and down movement of the needle 38, that is, the axis l3 of the needle bar 30. This end surface 81 forms an acute angle θ2 with the axis l2 of the lower shaft 28. This angle θ2 is, for example, 93 to 100 degrees. When the needle 38 enters the needle guide section 82 of the inner hook 55, the end surface 82a of the needle guide section 82 and the end surface 81 of the tip 57 are substantially parallel to the moving path of the needle 38. Further, even if the tip of the needle 38 comes into contact with the inclined surface 82b, the needle 38 can be guided into the needle guide section 82 by the inclined surface 82b.

FIG. 4 shows a needle 3 provided in a sewing machine 20 of the present invention.
FIG. 8 is a diagram for explaining the moving distance s of the tip P1 of FIG. In contrast to the needle 7 of the prior art described above, the needle 38 of the present invention is inclined by an angle θ1 with respect to the vertical line l4 or an angle θ2 with respect to the rotational axis l2 of the lower shaft 28. The tip P1 of the needle 38 is the tip P of the needle 7
It has been moved by a horizontal distance s from 0. Tips P when needle 7 and needle 38 reach their respective lowest points
0 and the tip P1 in the vertical direction is h, the distance s is expressed by the first equation or the second equation.

s=h・tanθ1...(1) s=h/tanθ2...(2) In this way, by inclining the movement path of the needle 38 by the angle θ2 with respect to the rotation axis l2 of the lower shaft 28, the bobbin 61 , that is, the length of flange 6
6 and 67 are connected to each other, and a cylindrical body 6 around which a bobbin thread 68 is wound.
5 in the axial direction can be increased by the distance s, thereby making it possible to increase the amount of winding of the bobbin thread 68.

As described above, according to the present invention, an excellent effect is achieved in that the amount of winding of the bobbin thread can be significantly increased. Furthermore, as mentioned above, the sewing machine 20
When the amount of winding of the bobbin thread 68 on the bobbin 61 is increased by tilting the needle 38 at an angle θ2 with respect to the rotation axis l2 of the lower shaft 28, the thread take-up 36 of the sewing machine 20
This has the advantage that there is no need to change the amount of needle thread let out. This also allows the invention to be easily implemented in conjunction with existing sewing machines.

Further, the present invention can also be carried out in connection with a sewing machine in which the inner hook 55 and the bobbin case 62 are integrally constructed, and the inner hook 55 includes:
The stud 63 may not be provided. Further, in the above embodiment, the axis l3 of the needle bar 39 is inclined toward the side away from the take-up cam 33, but it may be inclined toward the side closer to the take-up cam 33. This also makes it possible to increase the axial length of the bobbin 61 and increase the amount of rotation of the bobbin thread.

As an alternative embodiment, although the kettle in the above embodiments was a full-turn kettle, the invention could also be practiced with a half-turn kettle.

Effects As described above, according to the present invention, the axis l3 of the needle 38
is tilted with respect to a virtual plane perpendicular to the axis l2 of the lower shaft 28, so that the lowest end position of the needle 38 is aligned with the hook 30.
can be moved away from the bobbin 61 in the axial direction of the bobbin, thereby making it possible to increase the length of the bobbin in the axial direction, thereby making it possible to increase the amount of winding of the bobbin thread. Become.

Moreover, according to the present invention, the thread take-up amount may be the same as before, and the excellent effect of being able to be implemented in a wide range of applications in conjunction with existing sewing machines is achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a sewing machine 20 according to an embodiment of the present invention, FIG. 2 is a sectional view of a vertical full-rotation hook 30 provided in the sewing machine 20, FIG. 3 is an enlarged view of the vicinity of the tip 57, and FIG. FIG. 5, which is a diagram for explaining the moving distance s of the tip P1 of the needle 38 provided in the sewing machine 20 of the present invention, is a sectional view of a typical prior art. 20... Sewing machine, 21... Bed, 22... Main body, 23... Upper shaft, 25... Interlocking shaft, 28... Lower shaft, 30... Vertical full rotation hook, 32... Handwheel, 33... Balance Cam, 34... Balance link, 35... Crankshaft, 36... Balance, 37
... Connecting rod, 38 ... Needle, 39 ... Needle bar, 40 ...
...Guiding member, 50...Outer hook, 55...Inner hook,
61...Bobbin, 62...Bobbin case, l1...
...Rotation axis of the upper shaft 23, l2...Rotation axis of the lower shaft 28, l3...Axis of the needle bar 39, l4...Plumb line, θ1...Angle between the vertical line l4 and the axis l3 of the needle bar 39 , θ2 . . . An angle between the rotational axis l1 of the upper shaft 23 and the line l3 of the needle bar 39.

Claims (1)

[Claims] 1. A lower thread 68 is attached to a lower shaft 28 having a horizontal axis l2.
A rotary hook 30 is provided, which houses a bobbin 61 on which a needle is wound.
A sewing machine characterized in that the sewing machine is inclined with respect to a virtual plane perpendicular to the axis l2.