JPH0251634B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an engagement structure for a bobbin attached to a bobbin case.

Prior Art FIG. 10 is a perspective view of a typical prior art;
FIG. 11 is an exploded perspective view of the bobbin case 4 of the prior art. In hooks installed in lockstitch sewing machines, etc., the outer hook (not shown) has a rail on its outer circumferential surface.
The inner hook 2 having a formed thereon is attached, and the outer hook is driven to rotate around the rotational axis along the rail 1. A bobbin case 4 in which a bobbin 3 is housed is attached to such an inner hook 2.

The bobbin 3 includes a right cylindrical winding trunk 6 around which the bobbin thread 5 is wound, and a pair of flanges 7a and 7b fixed to both ends of the winding trunk 6. In the central hole 8 of the winding body 6 of such a bobbin 3,
The guide tube 9 of the bobbin case 4 is inserted, and the guide tube 9
A stud 12 erected on the bottom 11 of the inner pot 2 is inserted into the insertion hole 10 . A guide groove 20 is formed in the main body 13 of the bobbin case 4, and a latch 16 to which an operating piece 14 is connected by a pin 15 is mounted so as to be movable along the guide groove 20. The latch 16 is formed with an abutment surface 17;
The contact surface 17 has a spring hole 1 formed in the main body 13.
One end of a compression spring 19 housed in 8 resiliently abuts. As a result, the latch 16 is spring-biased in the direction of arrow A while being fitted into the guide groove 20 of the main body 13.

FIG. 12 is a cross-sectional view for explaining how the bobbin 3 is attached to the inner hook 2 of the prior art. Referring to FIG. 12, the bobbin case 4 containing the bobbin 3 is attached to the inner hook 2, and the substantially arc-shaped end surface 21a of the free end portion 21 of the stud 12 is connected to the edge of the insertion hole 22 of the latch 16. It is in a state of being in contact with the portion 23. In this state, when the bobbin case 4 is pressed toward the bottom 11 of the inner hook 2, the latch 16 moves in the direction of arrow B against the spring force of the compression spring 19, and the free end 21 of the stud 12 is inserted through the insertion hole 22 of the latch 16.

As shown in FIG. 12, the free end 21 inserted through the insertion hole 22 is in a state facing outward from the insertion hole 24 of the operating piece 14. In this state, the locking portion 26 of the latch 16 is fitted into the groove 25 of the stud 12, and the inner hook 2
The bobbin case 4 is locked. This prevents the bobbin 3 stored in the bobbin case 4 from separating from the inner hook 2 during sewing, and allows the bobbin 3 to be held within the inner hook 2.

Furthermore, when taking out the bobbin 3 from the inner hook 2 in the state shown in FIG.
As shown in , the operating piece 14 is pulled in the direction of arrow C to angularly displace the operating piece 14 around the axis of the pin 15, and the locking portion 26 of the latch 16 and the stud 1
The state of engagement with the concave groove 25 of No. 2 can be released. At this time, the bobbin holding portion 27 of the latch 16 is
The end surface 16a of the latch 16 is in contact with the outer peripheral surface of the flange 7a of the bobbin 3, and the end surface 16a of the latch 16 is connected to the cam surface 14 of the operating piece 14.
a, and movement of the latch 16 in the direction of arrow B is prevented. Thereby, the bobbin 3 can be taken out from the inner hook 2 while the bobbin 3 is engaged in the bobbin case 4.

Problems to be Solved by the Invention In the prior art described above, the height H of the bobbin case 4 is predetermined depending on the model of the sewing machine in the state shown in FIG. The needle thread payout amount of the thread take-up is determined.
In such a bobbin case 4, the length of the winding body 6 of the bobbin 3 in the axial direction is limited, so the width L of the bobbin 3 cannot be increased. Therefore, the amount of winding of the lower winding 5 wound around the bobbin 3 cannot be increased.

An object of the present invention is to solve the above-mentioned technical problems, and to increase the width L of the bobbin 3 without changing the height H of the bobbin case 4, so that the bobbin thread wound around the bobbin 3 can be easily wound. An object of the present invention is to provide a bobbin engagement structure that can increase the amount of bobbin engagement.

Means for Solving the Problems The present invention provides a bobbin engagement structure configured by inserting a guide tube of a bobbin case into a central hole of a bobbin winding body of the bobbin. It can be angularly displaced between a first position where it protrudes outward and locks onto the radially inner circumferential surface of the winding drum of the bobbin, and a second position where it is displaced radially inward from the first position. A locking member having a bobbin engaging portion is provided, and the bobbin engaging portion is in a first position when the bobbin is taken out from the bobbin case, and the bobbin is attached to the bobbin case for sewing. The bobbin engagement structure is characterized in that it is in the second position.

In a preferred embodiment, the locking member has an operating portion that partially fits into the guide tube and can be angularly displaced around an axis perpendicular to the axis of the guide tube.

In a preferred embodiment, the locking member is
A spring interposed between the inner peripheral surface of the guide tube and the locking member is elastically biased in a direction of angular displacement from the first position to the second position. do.

Function According to the present invention, a locking member having a locking piece that can be angularly displaced between a first position and a second position is provided in the guide cylinder of the bobbin case. This eliminates the need for traditional latches and studs.
Therefore, the length of the winding body of the bobbin in the axial direction can be increased by the thickness of the latch. As a result, the amount of winding of the bobbin thread around the bobbin can be increased.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a bobbin case 30 to which a bobbin 51 is attached.
3 is a perspective view of the inner hook 31, FIG. 4 is a perspective view of the bobbin case 30, and FIG. 5 is a perspective view of the vertical full rotation hook 71 with the bobbin case 30 attached. FIG. In FIG. 2, the bobbin case 30 is shown partially cut away for ease of illustration. Referring to FIGS. 1 and 2, the bobbin case 30 has a right cylindrical outer cylindrical portion 3 that fits into a recess 60 of an inner hook 31.
2. A main body composed of a bottom part 33 formed radially inward of the outer cylinder part 32 so as to close an opening on one side of the outer cylinder part 32, and a guide cylinder 34 erected at the center of the bottom part 33. 35, and a locking member 36 partially inserted into the guide tube 34.

The locking member 36 includes an operating piece 37 exposed outward from the guide tube 34 and a body portion 38 connected to the operating piece 37.
and an actuating portion 39 connected to the body portion 38, and the body portion 38 is formed with an insertion hole 41 through which a pin 40 is inserted. The body portion 38 also includes the insertion hole 4.
1 and the operation piece 37 from the insertion hole 41.
A spring receiving recess 42 is formed in the vicinity of the spring receiving recess 42, and one end of a compression spring 43 is accommodated in the spring receiving recess 42.

The actuating portion 39 includes a locking portion 45 having a flat locking surface 44a and a guide surface 44b formed in an arcuate or sloped shape, and a bobbin locking portion 47 having a pressing surface 46.

The guide cylinder 34 to which such a locking member 36 is attached has insertion holes 48a and 4 through which the pin 40 is inserted.
8b is formed by passing through the guide tube 34 in the diametrical direction, and on the free end side of the guide tube 34 from the insertion holes 48a, 48b, there is a through hole 49 through which the bobbin engaging portion 47 can pass freely. It is formed. The operating portion 39 and body portion 38 of the locking member 36 are inserted into the guide tube 34, and the pin 40 is inserted into the insertion hole 48.
a, 41 and 48b. Further, one end of a compression spring 43 is housed in the spring receiving recess 42, and the other end resiliently abuts against the inner circumferential surface 50 of the guide tube 34. As a result, the locking member 3
6, since the operating piece 37 is biased by a spring in the direction approaching the bottom part 33, the operating piece 37 contacts the bottom part 33 in the normal state shown in FIGS. 1 and 4, and the bobbin 51 described later The pressing surface 46 of the bobbin engaging portion 47 is maintained at a second position spaced apart from the inner circumferential surface 52a of the bobbin engaging portion 47.

Such a bobbin case 30 includes a bobbin 51.
is stored. The bobbin 51 consists of a right cylindrical winding trunk 52 and a pair of flanges 53a and 53b fixed to both ends of the winding trunk 52, and a bobbin thread 54 is wound around the winding trunk 52. Rolling trunk 52
The guide tube 34 is inserted into the central hole 55 defined by the inner circumferential surface 52a of the guide tube 34.

Referring also to FIG. 3, the bobbin case 30 containing such a bobbin 51 is attached to the inner hook 31. At the bottom 61 of the inner pot 31, the inner pot 3
A locking piece 62 is formed that stands upright toward the open end side of 1. The locking piece 62 has a right cylindrical cylindrical portion 63a.
and a locking protrusion 63b protruding radially inward from the free end of the cylindrical portion 63a. This locking protrusion 6
3b has a receiving surface 64 facing inward of the cylindrical portion 62a, with which the locking surface 44a of the locking member 36 comes into contact, allowing the bobbin case 30 to be locked to the inner hook 31. As shown in FIG. 5, such an inner hook 31 is attached to an outer hook 70 to form a vertical full rotation hook 71. In such a vertical full-rotation hook 71, the inner hook 31 has a tip portion of a rotation preventing member 72 fixed to the body of a sewing machine (not shown) in a rotation prevention recess 73 of the inner hook 31.
As a result, while the rotation of the inner hook 31 is stopped, the outer hook 70 is rotated around a horizontal axis of rotation, and sewing work can be performed.

FIG. 6 is a sectional view for explaining the operation of the bobbin case 30. Referring to FIG. 6, when the bobbin 51 is stored in the bobbin case 30 that has been removed from the inner hook 31 and the operating piece 37 of the locking member 36 is operated in the direction of the arrow D1, the locking member 36 is From the second position where the bobbin engaging portion 47 is separated from the inner peripheral surface 52a of the bobbin 51, the bobbin engaging portion 47 is angularly displaced around the axis of the pin 40, and the pressing surface 46 of the actuating portion 39 is pressed against the bobbin 51.
It comes into contact with and engages with the inner circumferential surface 52a of No. 1, and assumes the first position. Thereby, the bobbin 51 is locked in the bobbin case 30 without coming off from the bobbin case 30.

When installing the bobbin case 30 in which the bobbin 51 is stored in the inner hook 31 in this state, the locking piece 62 is inserted into the guide tube 34 as shown in FIG. , press the inner pot 31 in a direction approaching the bottom portion 61 along the central axis l1. At this time, the guide surface 44 of the locking member 36
b comes into contact with the edge 65 of the locking protrusion 63b, and as the bobbin case 30 is pressed, the guide surface 44b slides on the edge 65, and the locking member 36 moves from the second position to the axis of the pin 40. angular displacement in the direction of arrow D2.

As shown in FIG. 6, the locking portion 45 is fitted into the cylindrical portion 63a via the locking protrusion 63b. In such a state, the bobbin case 30
Direction for separating from the inner hook 31 (direction of arrow D3)
Even if an external force acts on the locking surface 44a, the receiving surface 64
The bobbin case 30 is locked by coming into contact with the bobbin case 31, and it is possible to prevent the bobbin case 30 from coming off from inside the inner hook 31.

Next, with the bobbin case 30 attached to the inner hook 31 (the state shown in FIG. 6 3), the bobbin case 30 is
0 from the inner hook 31, as shown in FIG. 46 comes into contact with the bobbin 51
In the first position where the bobbin 51 is locked to the bobbin case 30, the bobbin 51 can be smoothly pulled out without detaching from the bobbin case 30.

FIG. 7 is a sectional view showing a full rotary hook 80 showing another embodiment of the present invention. Note that the same reference numerals are given to parts corresponding to those in the above-described embodiment. The fully rotating hook 80 shown in FIG. 7 includes an outer hook 82 fixed to a rotating shaft 81 that is driven to rotate around a horizontal rotation axis, and an inner hook 84 attached to the outer hook 82.
The axis of rotation 83 of the outer hook 82 and the inner hook 8
The inner hook 8 forms an angle θ1 with the central axis 85 of 4.
4 is attached to the outer hook 82. This angle θ1
may be selected, for example, from 3 to 10 degrees.
By inclining the central axis 85 of the inner hook 84 and therefore the rotational axis of the bobbin 51 by an angle θ1 with respect to the rotational axis 83 of the outer hook 82,
The length of the bobbin 51, that is, the flanges 53a, 53
The length in the axial direction of the winding trunk 52 that connects the winding drum 52 can be made longer than the length L of the winding trunk 6 of the bobbin 3 of the prior art described above. Furthermore, by using the inner hook 84 and bobbin case 30 of the present invention in place of the conventional inner hook 2 and bobbin case 4, the conventional latch 1 shown in FIG.
The length corresponding to the thickness h of 6 can be further increased. This makes it possible to significantly increase the amount of winding of the bobbin thread 54 compared to the conventional method.

FIG. 8 is a sectional view of a full rotary hook 90 showing still another embodiment of the present invention. The full rotation hook 90 is
Rotation axis 9 of outer hook 92 fixed to rotation shaft 91
3 is inclined at an angle θ2 with respect to the horizontal axis. This angle θ2 may be selected, for example, from 3 to 10 degrees. Due to this, bobbin 51
The length of the winding trunk 52 in the axial direction can be increased, and the amount of winding of the bobbin thread 54 around the bobbin 51 can be increased.

FIG. 9 is a sectional view of a full rotary rotary hook 100 showing still another embodiment of the present invention. Full rotation hook 1
00 needle 101 is inclined by an angle θ3 with respect to a virtual plane perpendicular to the rotational axis of the outer hook. As a result, the tip end 102 of the needle 101 at the lowest end position can be moved in a direction away from the bobbin 51, thereby also increasing the axial length of the winding body 52 of the bobbin 51. Can be done. The present invention can also be implemented for such a full-rotation hook 100, and in addition to the amount of bobbin thread winding increased by tilting the needle 101 described above, the amount of winding of the bobbin thread 54 can be increased. It can be further increased.

In the embodiment described above as another embodiment,
Although a vertical full-rotation hook is used, the present invention can also be suitably implemented with a horizontal full-rotation hook.

Effects According to the present invention, by angularly displacing the locking member to the first position, the bobbin engaging portion locks onto the inner circumferential surface of the winding body of the bobbin. can be locked to the bobbin case. Therefore, when the bobbin is attached to the inner hook, the bobbin is prevented from being separated from the bobbin case, and the bobbin can be easily attached and detached. Furthermore, since the bobbin case of the present invention is not provided with a conventional latch, the length of the winding body of the bobbin in the axial direction can be increased by the thickness of the latch. The amount of winding of the bobbin thread can be increased.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is an exploded perspective view of the bobbin case 30 to which the bobbin 51 is attached, FIG. 3 is a perspective view of the inner hook 31, and FIG. 4 is the bobbin case 30. , FIG. 5 is a perspective view of the vertical full-rotation hook 71 with the bobbin case 30 attached, FIG. 6 is a sectional view for explaining the operation of the bobbin case 30, and FIG. 7 is a perspective view of another embodiment of the present invention. FIG. 8 is a cross-sectional view of a full-rotation hook 80 showing another embodiment of the present invention, FIG. 9 is a sectional view of a full-rotation hook 90 showing another embodiment of the present invention, and FIG. 9 is a full-rotation hook 100 showing another embodiment of the present invention. FIG. 10 is a typical prior art perspective view;
FIG. 11 is a sectional view of the prior art bobbin case 4;
FIG. 12 is a cross-sectional view for explaining how the bobbin 3 is attached to the inner hook 2 according to the prior art. 30... Bobbin case, 31... Inner hook, 34... Guide cylinder, 36... Locking member, 37... Operation piece, 38... Body, 39... Operating part, 40... Pin, 41... Insertion hole,
42... Spring receiving recess, 43... Compression spring, 44a...
Locking surface, 44b... Guide surface, 45... Locking portion, 46...
Pressing surface, 47...Bobbin engaging portion, 49...Through hole, 5
0...Inner peripheral surface of guide tube 34, 51...Bobbin, 52...
Rolling trunk, 52a...Inner circumferential surface of rolling trunk 52, 53
a, 53b...flange, 54...inner peripheral surface, 55...center hole, 61...bottom, 62...locking piece, 63a...cylindrical portion, 63b...locking protrusion.

Claims (1)

[Scope of Claims] 1. A bobbin engagement structure constructed by inserting a guide tube of a bobbin case into a central hole of a bobbin winding trunk, wherein a bobbin that protrudes outward in the radial direction is provided in the guide tube. a bobbin engaging portion that can be angularly displaced between a first position where it locks onto the radially inner circumferential surface of the winding trunk of the bobbin and a second position that is displaced radially inward from the first position; A locking member having a locking member is provided, and the bobbin engaging portion is in a first position when the bobbin is taken out from the bobbin case, and is in a second position when the bobbin is attached to the bobbin case and sewn. A bobbin engagement structure characterized by being in the position. 2. Claim 1, wherein the locking member has an operating portion that partially fits into the guide tube and can be angularly displaced around an axis perpendicular to the axis of the guide tube. The described bobbin engagement structure. 3. The locking member is connected to the first
The bobbin engagement structure according to claim 2, wherein the bobbin engagement structure is elastically biased in a direction of angular displacement from the position to the second position.