JPH03165796A - Perfect revolution of rotating hook for sewing machine - Google Patents

Abstract

PURPOSE:To prevent the generation of incidental looping and looping by forming the starting edge of a step difference surface on the upper stream side in the revolution direction of rotating hook than a supposed plane including the axis line of rotating hook bobbin case holder and the transfer passage of a needle, and smoothly string-laying a needle string loop. CONSTITUTION:A step difference surface 43 is formed on the bottom part 40 of an rotating hook bobbin case holder 20, and the starting edge P1 of the step difference surface 43 is formed on a upper stream side in the revolution direction of rotating hook 24 than a supposed plane including the axis line of the case holder 20 and the transfer passage of a needle. A needle string loop which shifts along the bottom part 40 can transfer to the edge surface close to the basic edge part of the bottom part 40 of the case holder 20 through the step difference surface, contracting the diameter after exceeding the lower edge part of the case holder 20, and the trouble with staying of the needle string loop on the step difference surface is prevented, and the string layer operation can smoothly be carried out. Accordingly, the generation of incidental looping, looping or string cut can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a full-rotation hook provided in a lockstitch sewing machine, a zigzag sewing machine, or the like.

Conventional technology Fig. 1O shows an inner pot 1 provided in a conventional vertical full-rotation hook.
FIG. 11 is a perspective view of the inner pot 1, and FIG. 12 is a perspective view of the inner pot 1 seen from the rear side. For example, an inner hook 1 provided in a vertical full-rotation hook includes a generally right cylindrical tube portion 2, a flange 3 that extends outward in the radial direction and extends from one end of the tube portion 2 in the axial direction, and a flange 3 that extends outward in the radial direction. 2, and a bottom portion 4 connected to the other end in the direction of the axis No.2. A rail 5 that fits into a track groove of an outer hook (not shown) is formed on the outer peripheral surface of the cylindrical portion 2, and a rail 5 is formed on the bottom portion 4 on the open end side of the inner hook 1, that is, on the front side with respect to the paper surface of FIG. A protruding stud 6 is provided upright, and a locking recess 7 is formed in the second flange 3 into which a protrusion of an inner hook locking member (not shown) fixed to the body of the sewing machine is fitted. The bottom portion 4 has a bridge 8 extending in the diametrical direction of the inner pot 1 and having a width W1 of about 8 mm, and a pair of openings 9 and 10 formed on both sides with the bridge 8 in between. These openings 9,
By forming the inner pot 10, the weight of the inner pot 1 can be reduced, and the inner pot 1 can be made lighter than the imaginary plane P that includes the moving path of the needle 11 and the axis l of the inner pot 1 shown by the imaginary line in FIG. The opening 9 formed on the downstream side in the rotary hook rotation direction A is large enough to allow the needle thread caught by the tip of the outer hook (not shown) to smoothly pass through the outer peripheral surface of the inner hook 1 while forming a needle thread loop. Affect.

FIG. 13 is a plan view of the inner pot 1, and FIG. 14 is a bottom view of the inner pot 1. As mentioned above, the needle thread T caught by the tip of the outer hook moves along the bottom surface 12 of the bottom part 4 in the direction indicated by the arrow m, to points C1, C2, C3, C4.
, C5 are moved in this order. Each of these points C1~
Of C4, C3 and C4 are at an angle θ(C3)-40 degrees from the virtual plane P, θ(C4)=15 in FIG.
The needle 11 and the thread T tend to stagnate at each point 03C4, and if the thread is a slippery thread, there is a problem that balls of thread or looping are likely to occur. Ta.

Problems to be Solved by the Invention Accordingly, an object of the present invention is to provide a full-turn sewing machine that can smoothly pass the needle thread loop and prevent the occurrence of yarn balls and looping. be.

Means for Solving the Problems The present invention forms a stepped surface at the bottom of the inner hook that smoothly extends to the flange near the bottom of the bobbin stored in the inner hook, and the starting end of this stepped surface is formed at the bottom of the inner hook. The full rotation hook of a sewing machine is characterized in that it is formed upstream in the direction of rotation of the outer hook with respect to a virtual plane including the axis of the needle and the movement path of the needle.

Further, in the present invention, a stepped surface is formed at the bottom of the inner hook that smoothly extends to the flange near the bottom of the bobbin stored in the inner hook, and the end of this stepped surface is connected to the axis of the inner hook and the movement of the needle. There is a full-rotation hook of a sewing machine characterized by being formed downstream in the direction of rotation of the outer hook than a virtual plane including the path.

Further, in the present invention, a step surface is formed at the bottom of the inner hook that extends smoothly at the flange area near the bottom of the bobbin stored in the inner hook, and the starting end of this step surface is connected to the axis of the inner hook and the needle. is formed upstream in the direction of rotation of the outer hook than the virtual plane including the movement path,
The sewing machine is characterized in that the terminal end of the stepped surface is formed downstream of the virtual plane in the direction of rotation of the outer hook.

According to the present invention, a step surface is formed at the bottom of the inner hook that smoothly extends to the flange near the bottom of the bobbin stored in the inner hook, so that the step surface extends smoothly from the step surface to the flange near the bottom of the bobbin stored in the inner hook. The flange does not protrude, and the needle thread loop 1 passing the thread along the bottom of the inner hook can smoothly pass the thread without being caught by the flange near the bottom of the bobbin. Moreover, the starting end of this stepped surface is located at Ujj, which includes the axis of the inner hook and the movement path of the needle.
Since the needle thread loop is formed upstream of the rotational direction of the outer hook from the rotational plane, the needle thread loop passes through the starting end of the stepped surface while reducing its diameter after passing the lowest position of the inner hook. The tension on the needle thread when the diameter is reduced is smaller than when the diameter is expanded, so even if there is a step, the needle thread can easily overcome the step, allowing the needle thread to move smoothly. This makes threading even easier.

Further, according to the present invention, the terminal end of the stepped surface is formed downstream of the virtual plane in the direction of rotation of the outer hook, so that the needle thread loop extends beyond the lowest end position of the inner hook with a reduced diameter. However, the needle thread passes through the end of the stepped surface, and the tension on the needle thread in such a reduced diameter state is smaller than when the diameter is expanded, so even if there is a step, the needle thread easily crosses the step. This allows the needle thread to move smoothly. This allows the needle thread to pass through the needle even more easily.

Furthermore, according to the present invention, the starting end of the stepped surface formed at the bottom of the inner hook is formed upstream in the rotational direction of the outer hook than a virtual plane including the axis of the inner hook and the thread path of the needle, and Since the terminal end of the surface is formed downstream of the virtual plane, as described above, only either the starting end or the terminal end is formed upstream in the rotating direction of the outer hook or in the rotating direction of the outer hook with respect to the virtual plane. Compared to forming the needle thread on the downstream side, it becomes possible to pass the needle thread more easily and smoothly.

Embodiment FIG. 1 is a front view of an inner pot 20 according to an embodiment of the present invention, FIG. 2 is a plan view of the inner pot 20, and FIG. 3 is a diagram showing how the inner pot 20 is stored. FIG. 4 is a sectional view of the vertical full-rotation hook 21 shown in FIG.
FIG.

First, with reference to FIGS. 3 and 4, the vertical full-rotation hook 21 of this embodiment has a lower shaft 22 that is rotationally driven around a horizontal axis l, and is fixed to the lower shaft 22 using a bolt 23. the outer hook 24, the inner hook 20, which is housed in the outer hook 24, the bobbin case 25, which is removably attached to the inner hook 20, and the bobbin thread 26, which is wound with the bobbin thread 26. The bobbin 27 is housed in the case 25.

A raceway groove 28 is formed on the inner peripheral surface of the outer hook 24.
Two rails formed on the outer peripheral surface of the inner hook fit into the inner hook 8. A detent recess 30 is formed in the inner hook 20, into which a convex portion of an inner hook detent member 36 fixed to the body of the sewing machine fits. Near the left side of the figure, a needle drop hole 33 is formed into which a needle 32 that reciprocates up and down as shown by arrow 31 is inserted.

A needle thread T is inserted through the needle 32, and the needle thread T is captured by a tip 35 provided on the outer hook 24.

Outer hook: As the i24 rotates downstream in the outer hook rotation direction A1, the needle thread T caught by the tip 35 forms a needle thread loop, and slides on the outer circumferential surface of the inner hook 20 while passing the thread. do. The inner pot 20 includes a cylindrical portion 38 which is formed into a roughly right cylindrical shape and has the two rails formed thereon, and a cylindrical portion 38.
The cylindrical portion 38 has three flanges extending radially outward from one end in the axis 1 direction of the cylindrical portion 38 and a bottom portion 40 extending from the other end in the axis r direction of the cylindrical portion 38 .

Referring to FIGS. 1 and 2, the bottom portion 40 has a line extending from the starting end P1 in the direction of rotation of the outer hook in the vicinity of a straight line indicating a virtual plane connecting the central axis l of the inner hook 20 and the moving path of the needle 32. A
An opening 41 is formed across one downstream end P2.

The starting end P1 is formed upstream of the outer hook rotation direction Al by an angle θ (Pl) from the straight line, and this angle θ (P
l) is 0 if the downstream side of the outer hook rotation direction Al is taken as the positive direction.
degree or less, preferably about -10 to -15 degrees. Further, the terminal end P2 is at an angle θ(P
2) is formed on the downstream side of the outer hook rotation direction AI,
This angle θ(P2) varies by about +150 degrees, for example. The opening 41 extending between the starting end P1 and the terminal end 22 is formed at an angle of approximately θ (Pl) through a stepped surface 43 that smoothly extends from the base end side of the inner pot 20, that is, the upper end surface 42 in FIG. The bridge 42 is continuous with the end surfaces 44 extending in the circumferential direction over +θ(P2), and the distance between the end surfaces 4244 in the axis l direction, that is, the thickness dl of the bridge 46 on which the studs 45 are erected is approximately 1.2 mm.

When the bobbin 27 is stored in the inner hook 20, the flange 47 of the bobbin 27 near the bottom 40
An end surface 18 facing outward through the opening 41 is substantially in the same plane as the end surface 44 . Further, in this state, the flange 47 of the bobbin 27 is in contact with the bridge 46, so that when the bobbin thread 26 is pulled out, the bobbin 27 can be rotated smoothly without rattling. can. Moreover, as mentioned above, the bottom 407
Since the end surface 48 of the flange 47 on i' does not protrude outward from the end surface 44 of the inner hook 20, even if the needle thread T moves in the direction of the arrow m1 when the outer hook rotates, the needle thread There is no risk that the needle thread T will get caught in the flange 47. Below, with reference to FIGS. 5 and 6, the needle thread T passing through the inner hook 20 and the associated operation of the vertical full rotation hook 21 will be explained. do.

FIG. 5 is a front view for explaining the operation of the vertical full-rotation hook 21 according to the present invention, and FIG. 6 is a side view of the inner hook 20 to which the bobbin case 25 is attached. First, Figure 6 (1
), the needle 32 and the tip 35 meet, and this tip 3
5 begins to capture the needle thread T. As the outer hook 24 rotates in the outer hook rotation direction A1 downstream,
When the state shown in FIG. 2 is reached, a needle thread loop T is formed by the tip 35, and the needle thread loop T is
0 gradually expanded near the lower end 49, and the axis line! In the direction, that is, in the left-right direction in FIG. 6, it is gradually expanded toward the bottom 40 of the inner pot 20 by the side surface 50 of the tip 35 (see FIG. 3).

The outer hook 24 further rotates downstream in the outer hook rotation direction A1, resulting in the states shown in FIG. 5 (2) and FIG. 6 (3)! When you get to the bottom,
The needle thread loop T is further enlarged and passes through the four lower ends of the inner 'i20. The balance side (not shown), that is, Fig. 6 (3)
) The needle thread T indicated by the arrow 51 is connected to the outer peripheral surface 52 of the inner hook 20.
from there onto the end surface 44 of the bottom portion 40.

When the outer hook 24 further rotates downstream in the outer hook rotating direction AI and reaches the state E shown in FIG. 5 (3) and FIG. 6 (4), the needle thread loop T expands to the maximum. Arrow on the balance side 51
The needle thread T shown by moves from the end surface 44 via the stepped surface 43 into a virtual plane including a straight line that is approximately at an intermediate position (FIG. 1) on the end surface 42 of the bridge 46 and the axis l. The reciprocating vertical movement of the thread take-up (not shown) and the rotation of the outer hook 24 are linked, and until the needle thread loop T passing around the inner hook 20 is expanded to the maximum, the thread take-up is T
In other words, the outer hook 24 moves further in the outer hook rotation direction A1 than in the state shown in FIG. 5(3). When the needle thread loop T rotates downstream, the needle thread loop T becomes surplus around the inner hook 20, so that the thread take-up starts an upward movement in order to absorb the needle thread T. During such thread passing operation of the needle thread loop T,
That is, during the operations shown in FIG. 6(2) to FIG. 6(4), the needle thread loop T can be transferred from the end surface 44 to the end surface 42 via the stepped surface 43 very smoothly, and as a result, the needle thread loop There is no danger that the movement of the needle thread T will be stagnant due to the needle thread T getting caught in the inner hook, and therefore the needle thread T from the thread take-up
There is no possibility that the amount of yarn fed becomes undesirably large, causing yarn balls, looping, or yarn breakage.

Further, when the outer hook 24 further rotates in the outer hook rotation direction A1 downstream from the state shown in FIG. Since it moves to the right side of the hook 20, the needle thread loop can smoothly pass over the thread according to the needle thread absorbing operation of the thread take-up. At this time, even though the needle thread loop T was stagnant until it reached Figure 5 (3) and the thread take-up had moved to the absorbing operation of the needle thread loop T, the needle thread loop If there is a T, there is a risk that the yarn ball, looping, or yarn breakage will occur, but in the present invention, the starting end P1 of the opening is provided on the upstream side of the outer hook rotation direction Al from the straight twist, and thereby each end face 4244 are smoothly connected via the step surface 43, the needle thread loop I as described above is
T does not stagnate, and the needle thread loop T can smoothly slide on the outer periphery of the inner hook 20 and be smoothly guided and moved along the end surface 44, the step surface 713, and the end surface 42, Therefore, the occurrence of thread breakage and the like described above can be reliably prevented.

No. 7I21 is a front view of the inner pot 20a of another embodiment of the present invention, and FIG. 8 is a front view of the inner pot 20a shown in No. 7UjJ.
FIG. 9 is a plan view of the inner pot 20 shown in FIG.
FIG. Note that the same reference numerals are given to parts corresponding to those in the above-described embodiment. What is noteworthy is the inner pot 20a.
The terminal end P2a of the opening 111 formed in the bottom 40 of the
It is formed at a position at an angle θ (P: 2a) from the straight line, and this angle θ (P2a) deviates by, for example, +180 degrees or more, preferably about +195 degrees. In this way, cross the starting end Pla and the ending end P2a to the seventh point.
By forming it on the right side of the figure, the above-mentioned figure 6 (
3) to the state shown in FIG. 6(5), the needle thread loop T passes from the end surface 44 to the end surface 42 via the stepped surface 43 while exceeding the lower end 49 of the inner hook 20a. Therefore, such an end face 44
There is no fear that the needle thread T will be caught when transferring from the needle thread to the end surface 42, and can move smoothly.

By forming the terminal end P2a in addition to the starting end Pla in this manner, it is possible to more reliably prevent the needle thread T from stagnation and to prevent the occurrence of thread breakage.

In the above-described embodiments, a sewing machine equipped with a full vertical rotary hook has been described, but the present invention can also be applied to a hook installed in a zigzag sewing machine.

Effects of the Invention According to the present invention, a stepped surface is formed at the bottom of the inner hook, and the starting end of the stepped surface is positioned in the direction of rotation of the outer hook than the virtual plane including the axis of the inner hook and the needle extension path. Since the needle thread is formed on the side, the needle thread loose moving along the bottom passes the bottom end of the inner hook and then transfers to the end surface near the proximal end of the bottom of the inner hook via the stepped surface while moving 1 fifi. This eliminates the risk of the needle thread loop becoming stagnant on the stepped surface, allowing smooth thread crossing operation.

This can prevent yarn balls, looping, or yarn breakage.

Further, according to the present invention, the terminal end of the stepped surface is formed downstream of the virtual plane in the direction of rotation of the outer hook, so that the needle thread loop passes through the lower end of the inner hook while reducing its diameter. The needle thread can be transferred to the end surface near the proximal end of the inner hook via the step surface, and as a result, the needle thread does not stagnate near the step surface, and the thread passing operation can be carried out smoothly and easily. This can prevent yarn balls, looping, or yarn breakage.

Furthermore, according to the present invention, the starting end of the step surface is formed upstream in the rotational direction of the outer hook than the virtual plane of the inner hook, and the terminal end of the step surface is formed downstream in the radial direction of the outer hook than the virtual plane. As a result, the needle thread loop moves through the stepped surface while reducing its diameter, so there is no risk of the needle thread becoming stagnant on the stepped surface, thus ensuring the occurrence of yarn balls, looping, or thread breakage. can be prevented.

Moreover, according to the present invention, only the inner pot needs to be replaced, so it has the excellent effect that it can be widely implemented in conjunction with conventional pots.

[Brief explanation of the drawing]

FIG. 1 is a front view of an inner pot 20 according to an embodiment of the present invention, and FIG.
The figure is a plan view of the inner pot 20, and the third figure is the inner pot 20.
FIG. 4 is a sectional view of the vertical full-rotation hook 21 in which the rotary hook 21 is housed, and FIG. 4 is an overall perspective view of the vertical full-rotation hook 21 shown in FIG. 3.
The figure is a front view for explaining the operation of the vertical full-rotation hook 21 according to the present invention, FIG. 6 is a side view of the inner hook 20 with the bobbin case 25 attached, and FIG. 7 is another embodiment of the present invention. 8 is a plan view of the inner pot 20a shown in FIG. 7, and FIG. 9 is a front view of the inner pot 20a shown in FIG.
Fig. 10 is a front view of the inner pot 1 provided in a conventional vertical full-rotation hook, Fig. 11 is a perspective view of the inner pot 1, and Fig. 12 is a rear view of the inner pot 1. Perspective view from
FIG. 13 is a plan view of the inner pot 1, and FIG. 14 is a bottom view of the inner pot 1. 20.20a...Inner hook, 21...Vertical full rotation hook, 211...Outer hook, 27...Bobbin, 32...Needle, 4o...Bottom, 41...Opening ,42.44...
End surface, 43...step surface, Pl, Pla--starting end, P2
．． P2a-p end, L...straight line, T...needle thread

Claims (3)

[Claims] (1) A stepped surface is formed at the bottom of the inner hook that smoothly extends to the flange near the bottom of the bobbin stored in the inner hook, and the starting end of this stepped surface is aligned with the axis of the inner hook and the movement path of the needle. A full-rotation hook for a sewing machine, characterized in that the hook is formed upstream in the direction of rotation of the outer hook than a virtual plane containing the hook. (2) A stepped surface is formed at the bottom of the inner hook that smoothly extends to the flange near the bottom of the bobbin stored in the inner hook, and the end of this stepped surface is aligned with the axis of the inner hook and the movement path of the needle. A full-rotation hook of a sewing machine, characterized in that the hook is formed downstream in the direction of rotation of the outer hook than a virtual plane containing the hook. (3) A stepped surface is formed at the bottom of the inner hook that smoothly extends to the flange near the bottom of the bobbin stored in the inner hook, and the starting end of this stepped surface is aligned with the axis of the inner hook and the movement path of the needle. is formed upstream in the direction of rotation of the outer hook than the virtual plane containing the
A full-rotation hook for a sewing machine, characterized in that a terminal end of the step surface is formed downstream of the virtual plane in the rotational direction of the outer hook.