JPH02134190A - Half-rotating hook - Google Patents

Abstract

PURPOSE:To improve the winding amount of a bobbin thread in a bobbin by providing on a bobbin case supporting member provided concentrically with the shuttle body rotating center in such a manner as to be capable of mutual angular transformation with the shuttle body and whirl-stopped to a sewing machine body, a stud passing a supporting a bobbin case with being slipped from the shuttle body rotating center. CONSTITUTION:A half-rotating hook 20 consists of a shuttle body 25 supported by a shuttle race body 22, a bobbin case supporting member 26 provided thereto in such a manner as to be capable of mutual angular transformation, a bobbin case 28 installed to a stud 27 provided on said member, and a bobbin 30. The central axial line 12 of the stud 27 is disposed lower than the rotating axial line 11 of the shuttle body 25 by a distance d. The fitting part of the bobbin case supporting member 26 is fitted to the recessed part of the shuttle race body 22 to prevent its rotation accompanied by the reciprocating half-rotating motion of the shuttle body 25. The fitting part 43 is fitted to the recessed part of the bobbin case 28 to prevent its rotation. The diameter of the bobbin case 28 can be increased by the distance d, and also the diameter of the bobbin 30 can be also increased. Thus, the winding amount of the bobbin thread can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a semi-rotary hook provided in household sewing machines, industrial sewing machines, and the like.

Conventional technology FIG. 7 is a front view showing a half-rotation hook 1 from &1u,
FIG. 8 is an exploded perspective view of the half-rotation kettle 1 shown in FIG. 7. A half-rotary hook 1, which is installed in household sewing machines, industrial sewing machines, etc., includes an inner hook 3 in which a rail 2 is fitted into and supported by a rail groove formed on the inner peripheral surface of a large hook (not shown), and a bobbin thread 4. The bobbin case 6 is attached to the inner hook 3 in a state where the wound bobbin 5 is stored therein. The inner hook 3 is driven half a turn around the horizontal axis of rotation l, catches the upper thread brought by the needle 7 that reciprocates up and down with the tip 8, rotates in the direction of arrow A1, and threads the upper thread upward. Form a thread loop. The needle thread loop thus formed slides on the outer circumferential surface of the bobbin case 6 and is pulled upward by a thread take-up linked to the needle 7, and meshes with the bobbin thread 4 pulled out from the bobbin case 6 to complete the stitch. It is formed.

The inner hook 3, with the upper thread released from the tip 8, rotates half a turn in the direction of arrow A2 and returns to its initial position, and again picks up the upper thread, which has been brought near the tip 8 by the downward movement of the needle 7. While catching, a needle thread loop is formed, the needle thread is rotated half a turn in the direction of arrow A1, and the above-mentioned operation is repeated to form a continuous stitch. A rotation preventing member 9 is formed on the bobbin case 6,
The rotation prevention member 9 is fitted into a rotation prevention recess 11 formed in the inner hook holder 10, and is locked so that the bobbin case 6 does not rotate when the inner hook 3 rotates half a rotation.

By the way, when the above-mentioned half-rotation hook 1 is used in an industrial sewing machine that has a faster sewing speed than a general household sewing machine, the diameter D1 and width B of the bobbin 5 are constant, and the winding around the bobbin 5 is constant. There is a limit to increasing the amount of winding of the bobbin thread.

When the bobbin thread 4 of the bobbin 5 is used up, it must be replaced with a new bobbin wound with a new bobbin thread.Especially in industrial sewing machines where the sewing speed is fast and the amount of sewing is large, A problem arises in that the bobbin 5 must be replaced frequently, which reduces the efficiency of sewing work.

Conventionally, attempts have been made to increase the amount of winding of the bobbin thread by increasing the diameter of the inner hook 3 or increasing the thickness of the hobbin 5 and bobbin case 6. As a result, the diameter of the loose upper thread that is pulled out below the throat plate of the sewing machine by the inner hook 3 increases, which not only causes poor thread tightness, but also increases vibrations associated with half-rotation operation, and as a result, The rotation speed will have to be reduced.

Problems to be Solved by the Invention Therefore, an object of the present invention is to solve the above-mentioned technical problems, to make the outer diameter of the inner hook the same without major modification of the sewing machine, and to improve the winding of the bobbin thread wound around the bobbin. To provide a half-rotation hook capable of increasing the amount of sewing work and improving the efficiency of sewing work.

Means for Solving the Problems The present invention provides a half-rotation hook constructed by attaching a bobbin wound with bobbin thread to a bobbin case, and attaching this bobbin case to an inner hook. A bobbin case supporting member (+m) is installed so that it can be angularly displaced with respect to the inner hook concentrically with the center of rotation of the inner hook, and is stopped from rotating by patting the sewing machine body. There is also a half-rotation hook in which the stud that is inserted and supported is offset from the axis of the stud or the center of rotation of the inner hook.

According to the present invention, it is provided on the inner surface of the bottom of the inner hook so that it can be angularly displaced with respect to the inner hook, concentrically with the center of rotation within the inner hook, and is locked to the sewing machine body to prevent rotation. A bobbin case support member is provided, a stud is provided on the bobbin case support member at a position offset from the center of rotation of the inner hook, and the bobbin case is attached to the stud by 1A, so that the inner hook reciprocates during sewing. The bobbin case support member and the bobbin case will not rotate during half-rotation (1). Also, the diameter of the bobbin case should be The diameter of the bobbin housed in such a bobbin case can be increased to increase the amount of bobbin thread wound on the bobbin. It becomes like this.

Embodiment FIG. 1 is a sectional view of a half-rotation hook 20 according to an embodiment of the present invention, and the second half-rotation hook 20 shown in FIG.
FIG. Throat plate 2 installed in the sewing machine bed
A half-rotation hook 20 is provided below the rotor 1. The half-rotation hook 20 includes an inner hook 25 in which a rail 24 is fitted into and supported by a rail groove 23 formed on the inner peripheral surface of the large hook 22, and a bobbin case provided on the inner hook 25 so as to be mutually angularly displaceable. It includes a support member 26, a bobbin case 28 attached to a stud 27 provided on the support member 26, and a bobbin 30 housed in the bobbin case 28 and around which a bobbin thread 29 is wound.

When the sewing operation is started, the inner hook 25 is driven to reciprocate by half a rotation around the horizontal axis of rotation 11 in the directions of arrows C1 and C2, and as the inner hook 25 moves half a rotation, the needle 31 moves up and down. It moves back and forth. At the lowest position shown in the first [2I], the tip of the needle 31 is located above the rotational axis 11 by a distance 4i I-1, and this distance 11 is equal to the outer periphery of the bobbin thread wound on the bobbin. , is predetermined to such an extent that the tip of the needle 31 does not touch. The center axis 12 of the stud provided on the support member 26 is spaced downwardly by a distance d from the rotation axis 11, and these axes 1
1.12 are mutually parallel.

FIG. 3 is a perspective view of the inner hook 25 and the bobbin case support member 26, and 412ff is a partially enlarged sectional view showing the shape of the bobbin case support member 26 attached to the inner hook 25. An insertion hole 36 is formed in the bottom 35 of the inner hook 25 to be inserted in the thickness direction along the rotation axis 11, and a main body portion 37 of the support member 26 is inserted into the insertion hole 36.
A boss 38 formed in is inserted therethrough. The boss 38 has three internally threaded screw holes formed on its inner peripheral surface, into which bolts 40 are screwed. In the state in which the bolt 40 is screwed onto the support part 1''i26 in this way, the rising height Sl of the boss 38 is slightly thicker than the thickness S2 near the insertion hole 36 of the bottom 35 (st>s2). As a result, the support member 26 is rotatably dimensioned with respect to the inner hook 25.The head 41 of the bolt 40 is formed in the bottom 35 over an area including the insertion hole 36. The bolt head 41 is housed in the recess 42 and is configured so that the bolt head 41 does not protrude from the outer peripheral surface 35a of the bottom 35.

Support member 26 attached to inner hook 25 in this way
The stud 27 has a center axis 12 that is eccentric downwardly (downward in FIG. 4) by a distance fid with respect to the axis of rotation 11.
has been erected.

5 is a perspective view of the bobbin case support member 26, and FIG. 6 is a perspective view of the bobbin case 28.

The above-mentioned support member 26 includes the main body portion 37, a first fitting portion 43 that is bent and connected to the main body portion 37, and a first fitting portion 43 that is further bent and connected to the first bloom portion 13, and is tapered toward the free end side. A second fitting portion 44 having a shape is formed. The second fitting portion 44 fits into a detent recess of an unillustrated inner hook holding member provided in the large hook 22, whereby the support member 26 is rotated at the arrow mark C of the inner hook 25.
It is prevented from rotating due to the reciprocating half-rotation movement in the 1C2 direction. Further, the first fitting portion 43 fits into a fitting recess 45 formed on the outer peripheral surface of the bobbin case 28, thereby preventing the bobbin case 28 from rotating.

In such a bobbin case 28, the cylindrical body 46 into which the stud 27 of the support member 26 is inserted is aligned along the central axis 13.
), and when the cylindrical body 46 is attached to the stud 27, the central axis 13 and the central axis 12 of the stud 27 are in a straight line. The diameter D2 of the bobbin case 28 is expanded in the radial direction l\, that is, the distance is regulated by the lowest point of the needle 31 shown in FIG. The distance Ji h can be set large, and therefore the eccentric distance (l) can be made twice as large (D2=D+2d) as compared to the diameter of the bobbin case 6 of the prior art. The diameter D3 of the bobbin 30 (
(see Figure 1). The amount of winding of the two bobbin threads wound around the bobbin 30 is significantly increased compared to the prior art, thereby eliminating the need to frequently replace the bobbin during sewing operations.

Effects of the Invention According to the present invention, the bobbin case support member is provided on the inner hook, and the axis of the stud is provided on the bobbin case support member at a position offset from the center of rotation of the inner hook. This makes it possible to increase the size of the bobbin by twice as much as the distance between the two, making it possible to increase the size of the bobbin that is housed in the bobbin case. Therefore, the amount of bobbin thread wound around the bobbin can be increased, and the bobbin does not need to be replaced frequently during sewing, reducing the number of bobbin replacements and improving the efficiency of sewing work. be able to. In addition, since the bobbin case is attached to the inner hook via the support member, the bobbin case is prevented from producing a crank-like movement due to the half-rotation movement of the inner hook. Durability does not decrease due to wear associated with movement. Furthermore, since there is no need to increase the diameter of the inner hook, the half-rotation hook of the present invention can be easily attached to an existing sewing machine without requiring any modification of the sewing machine body as in the prior art described above. The invention can be implemented in a wide range of ways.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a half-rotation hook 20 according to an embodiment of the present invention;
FIG. 2 is a perspective view of the vicinity of the half-rotation hook 20 shown in FIG. 1, and FIG. 3 is a perspective view of the inner hook 25 and the bobbin case support member 26.
FIG. 4 is a partially enlarged sectional view showing the state of the slot 1 of the bobbin case support member 26 attached to the inner hook 25;
FIG. 5 is a perspective view of the bobbin case support member 26, No. 6I2
1 is a simplified perspective view of the bobbin case 28;
is a front view showing a conventional half-rotation or tl, and FIG. 8 is an exploded perspective view of the half-rotation hook 1 shown in FIG. 7. 20..Half rotation, 25..Inner hook, 26..Bobbin case support member, 27..Stud, 28..Bobbin case, 29..Bobbin thread, 30..Bobbin, 31..Needle, 1
! 1 Rotation axis of the inner hook 25, 12... stud 2
7 central axis,

Claims (1)

[Scope of Claims] In a half-rotation hook configured by attaching a bobbin wound with bobbin thread to a bobbin case and attaching this bobbin case to an inner hook, the center of rotation of the inner hook is located on the inner surface of the bottom of the inner hook. A bobbin case support member is provided concentrically with the inner hook so as to be angularly displaceable relative to the inner hook, and is locked to the sewing machine body to prevent rotation.A stud for inserting and supporting the bobbin case is inserted into the bobbin case support member. , a half-rotation hook characterized in that the axis of the stud is offset from the center of rotation of the inner hook.