JPH01119287A - Device for uniforming diameter of bobbin for thread winding apparatus - Google Patents

Abstract

PURPOSE: To uniform the bobbin winding diameter of a thread to be wound by a bobbin thread bobbin between both flange parts by providing a cam body for setting the length of a thread supply path to almost equalize the length of the thread supply path from a thread guide to the bobbin thread bobbin even at any position between both the flange parts. CONSTITUTION: A cam body 28 erected on the thread supply path from a thread guide 20 to a bobbin thread bobbin 24 inserted and attached to a winding shaft 22 is composed of a plate body, with which an arcuate cam face 28a is formed on one vertical side, and vertically supported so as to be turned on the top of a sewing machine frame 10 by a supporting shaft 30 projected on the bottom thereof. The cam face 28a is formed into curved surface most protruding its central part, and made suitable for the case of installing a thread feeding position O at the height located in the middle of both flange parts 24b and 24c of a bobbin thread bobbin 24. With this cam face 28a, the length of the thread supply path for a thread 16 from the thread feeding position O to the bobbin thread bobbin 24 is almost equalized even at any position between both the flange parts 24b and 24c and the bobbin winding diameter of the thread to be wound by the bobbin thread bobbin 24 is uniformed between both the flange parts.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a thread winding diameter equalizing device for a bobbin thread winding device, and more particularly, to a thread winding diameter equalizing device for a bobbin thread winding device, and more specifically, for winding thread onto a bobbin thread bobbin with a bobbin thread winding device of a sewing machine. This invention relates to a spool diameter equalizing device that can wind the spool so that the spool diameter is uniform.

In a bobbin thread bobbin that is loaded into a rotary hook of a conventional sewing machine and supplies bobbin thread during sewing, winding of the bobbin thread onto the bobbin thread is generally performed by a bobbin thread winding device attached to the sewing machine. There are various configurations of this bobbin thread winding device, but for example, a bobbin thread bobbin is inserted into a bobbin shaft that projects vertically from the top of the sewing machine frame, and this bobbin thread winding device is powered by a power branched from the main shaft of the sewing machine. A configuration in which the lower thread from the thread spool is wound onto the bobbin by rotating the bobbin is widely put into practical use.

That is, as shown in FIG. 4, a thread spool 18 wound with thread 16 is freely inserted into and removed from a thread spool 14 installed horizontally in a recess 12 at the center of the top of the sewing machine frame 10. Machine frame 10
A support member 26 protruding from the top left side is provided with a thread guide body 20 that hooks the thread 16 pulled out from the thread spool 18 and guides it to the right.

On the right side of the top of the sewing machine frame 10 (on the side of the hand pulley 11), a thread winding shaft 22 into which a bobbin thread bobbin 24 can be inserted is rotatably installed, and is rotated by power branched from the main shaft of the sewing machine. There is. Furthermore, adjacent to the thread winding shaft 22,
A pressure contact body 23 for automatically stopping the bobbin winding is provided upright.

When winding the bobbin thread, the thread 16 is pulled out from the thread spool 18 to the left, hung on the thread guide 20, and then turned back to the right.
The end of the thread is wound around the lower thread bobbin 24 inserted into the thread winding shaft 22, and the thread winding shaft 22 is rotated in this state. As a result, the thread 16 is unwound from the thread spool 18 via the thread guide 20 and wound around the light take-up shaft 24a of the bobbin thread bobbin 24. When the winding diameter increases by this bobbin winding and reaches the required amount,
The thread winding portion comes into contact with the pressing body 23 and a biasing force is applied to the thread winding shaft 22, so that the rotation of the thread winding shaft 22 is automatically stopped.

Problems to be Solved by the Invention When thread is wound around a bobbin thread bobbin using the bobbin thread winding device as described above, the bobbin thread bobbin 24 is inserted into the bobbin winding shaft 2.
Depending on the distance between the thread guide member 20 and the thread guide member 20, the diameter of the thread wound on the bobbin may not be uniform, and more thread is wound only in the center, and less thread is wound toward the flanges at both ends of the barrel. This often results in defects such as the shape (see FIG. 5(b)).

For example, as shown in FIG. 5(a), the thread 16 let out from the thread spool is supplied to the lower thread bobbin 24 via the thread guide 20. In this case, the thread 16 is fed to the thread guide 20. It is always sent from a predetermined position NO. Therefore, when winding the bobbin thread, the thread 16 touches both flanges 24 of the bobbin thread bobbin 24.
The yarn is wound while reciprocating in an arc of radius R centered on the yarn delivery position rIio during the interval c. and,
As the separation distance between the thread guide 20 and the bobbin winding shaft 22 becomes shorter, the thread 1 on the bobbin thread bobbin 24 becomes shorter as shown in FIG.
In the winding form No. 6, a large amount of thread is wound only in the center part, and the thread is wrapped around the flange part 2.
4 becomes a barrel shape with fewer windings as it approaches 24c.

The reason for this is that the distance from the thread sending position O of the thread guide 20 to the light take-up shaft 24a of the bobbin thread bobbin 24 (in other words, the thread winding shaft 22) is the shortest at the middle part of the light take-up shaft 24a. ,
Upper or lower collar portion 24b.

The reason is that it gets longer towards 24c. Namely.

The shorter the distance from the yarn delivery position o to the light take-off shaft 24a,
The tension applied to the thread 16 during winding becomes lower, and the longer the distance, the higher the tension applied to the thread 166. For example, as schematically shown in FIG. 6(a), Distance A to midpoint a of the take-up shaft 24a
ii n t is the shortest and the tension applied to the thread 16 is the lowest, and ■ distance #tn2 from the thread delivery position o to the upper end and distance Q to the lower end C are the longest and the tension applied to the thread 16 is the highest. Become. Therefore, a large amount of the thread 16 is wound around the middle portion of the thread winding shaft 22 where the tension is lowest, resulting in the above-mentioned barrel shape. In this way, if the bobbin thread bobbin 24 is wound unevenly, the thread tension for pulling out the bobbin thread may vary when the bobbin thread bobbin 24 is used.

Therefore, in order to keep the tension constant when winding the thread onto the bobbin thread bobbin 24, the distance - between the thread delivery position O of the thread guide 2o and the light take-up shaft 24a of the bobbin thread bobbin 24 should be set as long as possible. It has been known. That is, as schematically shown in FIG. 6(b), if the above-mentioned separation distance is set as long as possible, the distance a from the yarn delivery position NO to the midpoint a of the optical axis 24a
nx and the distance from the yarn delivery position 0 to the upper end 1iIiQ2
and the distance Q3 to the lower end C is almost equal to CQ2'
9m1~Ω3), the above-mentioned tension difference becomes a negligible value. Therefore, as shown in FIG. 5(a), the longer the distance between the thread feed quality Ro and the thread take-up shaft 24a, the larger the radius R of the arc drawn by the reciprocating movement of the thread 16 when winding the bobbin thread. The difference in distance between the middle, upper and lower parts of the thread take-up shaft 24a becomes almost negligible. Therefore, the tension difference is almost eliminated, and the thread 16 wound on the bobbin thread bobbin 24
The thread winding diameter of the bobbin 24 is approximately the same in the intermediate portion and both collar portions 24 at any location near the bobbin 24c.

However, setting the distance between the thread guide body 20 and the thread take-up shaft 24a to be long as described above has an undesirable effect on the external design of the sewing machine, limits the mechanical layout, and increases the overall size. There are serious drawbacks.

OBJECTS OF THE INVENTION The present invention has been proposed in view of the above-mentioned drawbacks inherent in conventional sewing machine bobbin thread winding devices, and has been proposed to suitably solve these problems. To provide a device which can make the winding diameter of a lower thread wound around a lower thread bobbin uniform regardless of the circumstances, and is not limited by external design or mechanical layout.

Means for Solving the Problems In order to overcome the above-mentioned problems and suitably achieve the intended purpose, the bobbin winding diameter equalizing device according to the present invention has the following features: In a bobbin thread winding device for winding a bobbin thread bobbin inserted into a bobbin thread winding shaft, the length of the thread supply path from the thread guide to the bobbin thread bobbin inserted into the bobbin winding shaft is longer than the bobbin thread winding device. A cam body is provided to set the length of the thread supply path so that the length of the thread supply path is approximately the same no matter where the thread is wound between the flanges of the bobbin. The present invention is characterized in that the thread winding diameter of the bobbin thread bobbin is made equal between both flanges by engagement with the cam body.

Embodiment Next, a preferred embodiment of the thread winding diameter equalizing device for a bobbin thread winding device according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial plan view of a sewing machine equipped with a bobbin winding diameter equalizing device according to an embodiment, and FIG. 2 is a partial front view showing the sewing machine shown in FIG. 1 in longitudinal section. Note that the members that have already been mentioned will be indicated by the same reference numerals.

On the right side of the top of the sewing machine frame 10, a thread winding shaft 22 that is rotated by power branched from the main shaft of the sewing machine is installed. A thread guide body 20 that guides the thread 16 to be paid out to a bobbin thread bobbin 24 inserted into the thread winding shaft 22 is disposed via a support member 26. In this case, the thread delivery position O at which the thread 16 is delivered from the thread guide body 20 is configured to always be at the same position in the axial direction of the thread winding shaft 22. The lower thread bobbin 2 is inserted from the thread guide body 20 to the thread winding shaft 22.
A cam body 28 having the shape shown in the figure is provided upright on the yarn supply path extending up to 4.

As shown in FIG. 2, the cam body 28 is configured as a plate having an arcuate cam surface 28a formed on one side in the vertical direction, and is supported by a support shaft 30 protruding from the bottom of the cam body 28.
It is vertically supported rotatably on the top of the 0. The cam surface 28a has a curved shape in which the central portion thereof protrudes the most;
When the thread delivery position 0 is set to 24c, both flanges 24 of the bobbin thread bobbin 24 are
Suitable when installed at a height between .

Due to this curved cam surface 28a, the length of the thread supply path of the thread 16 from the thread delivery position O to the bobbin thread bobbin 24 is approximately equal to the length of the thread supply path of the thread 16 from the thread delivery position O to the bobbin thread bobbin 24 at any point between both flanges 24 of the bobbin thread bobbin 24 and 24c. are set to be equal.

That is, 1. As schematically shown in FIG. 6(a).

When the cam body 28 is not provided, the length of the thread supply path for the thread 16 from the thread sending position O of the thread guide 20 to the thread take-up shaft 24a of the bobbin thread bobbin 24 is the longest at the center of the thread take-up shaft 24a. The center part of the cam surface 28a protrudes by an amount corresponding to the difference between the longest yarn supply path and the shortest yarn supply path, and the length at each position of the cam surface 28a increases. The amount of protrusion is set to be an amount corresponding to an error of the yarn supply path at each position with respect to the longest yarn supply path.

At both upper and lower ends of the plate body 32 of the guide body 28, there are regulating portions 28 that protrude outward from the cam surface 28a.
is provided, and the thread 16 moving on the cam surface 28a is connected to the cam body 2.
Try not to leave from 8. Further, the support shaft 30
is pivotably supported on the sewing machine frame 10, so
The position of the cam surface 28a with respect to the bobbin shaft 22 can be changed by mvm, thereby allowing the bobbin thread bobbin 2 to be moved from the cam surface 28a.
The length of the yarn supply path leading to 4 can be adjusted.

Next, FIG. 3 shows a modified example of the embodiment shown in FIG. pulled out thread 1
6 is wound around the lowermost part of the light take-up shaft 24a of the bobbin thread bobbin 24. In this case, the length of the yarn supply path from the yarn delivery position O to the light take-off shaft 24a becomes longer as it moves above the light take-off shaft 24a. Therefore, as shown in FIG. 1, the cam surface 28 of the cam body 28
a is formed as an arcuate surface that recedes from the bobbin winding shaft 22 as it moves upward, so that both flanges 24 of the bobbin thread bobbin 24 can be adjusted to the length of the thread supply path at any position between 24c. are set so that they are approximately equal. Therefore, after the thread 16 supplied via the thread guide body 20 is engaged with the cam surface 28a of the cam body 28, the lower thread bobbin 24
If the bobbin thread bobbin 24 is wound with
The two flange portions 24 of a and 24c are equal.

Conversely, if the thread 16 pulled out horizontally from the thread feed quality [0 is wound on the top of the light take-up shaft 24a of the bobbin thread bobbin 24, the cam surface 28 of the cam body 28
a may be formed into an arcuate surface having a shape that recedes from the pincushion shaft 22 as it moves downward.

Next, the operation of the bobbin winding diameter increasing device according to the embodiment configured as described above will be explained. First, the bobbin thread bobbin 24 is inserted into the thread winding shaft 22 so as to be rotatable therewith.

Also, pull out the thread 16 from the thread spool 18 to the left, and
0, turn it back to the right, engage it with the cam surface 28a of the cam body 28, and then attach it to the light take-up shaft 24a of the bobbin thread bobbin 24.
Wrap it around.

When the bobbin winding shaft 22 is rotated in this state, the thread 1 passes from the thread guide body 20 through the cam body 28 and is wound around the bobbin thread bobbin 24.
6 is wound around the bobbin thread bobbin 24 while reciprocating up and down on the cam surface 28a of the cam body 28. As mentioned above, the cam surface 28a is formed into a curved shape with the center portion protruding the most.

The yarn feed quality of the yarn guide body 20 [the length of the yarn supply path of the yarn 16 from 10 to the cam surface 28a is longer at the center of the cam surface 28a, and becomes shorter as the regulating portion 28 approaches the cam surface 28b. . On the contrary, the bobbin thread bobbin 24 is engaged with the cam surface 28a.
The length of the thread supply path for the thread 16 wound on the lower thread bobbin 24 is short at the middle part of the bobbin thread bobbin 24, and becomes longer as it approaches both flanges 24 to 24c.

Therefore, the total length of the thread supply path from the thread feed quality No. to the bobbin thread bobbin 24 is equal, and the tension applied to the thread 16 at the time of winding the bobbin thread is approximately equal at any position on the bobbin thread bobbin 24. The thread winding diameter of the thread bobbin 24 is determined by the diameter of the thread bobbin 24.
Both flange portions 24b of a.

It becomes uniform between 24c.

As described in detail of the invention, according to the bobbin thread diameter reducing device for a bobbin thread winding device according to the present invention, the length of the thread supply path from the thread guide body to the bobbin thread bobbin is equal to that of both flanges. Since the diameter of the thread to be wound around the lower thread bobbin can be made uniform between the two flanges, the diameter of the thread to be wound around the lower thread bobbin can be made uniform. In addition, since there is no need to set a long distance between the thread guide and the bobbin winding shaft, there are no restrictions on the design of the sewing machine or the layout of other mechanisms, and the sewing machine can have a compact configuration. be effective.

[Brief explanation of the drawing]

The drawings show an embodiment of a bobbin winding device for a bobbin thread winding device according to the present invention. 1 is a partial front view taken longitudinally of the sewing machine shown in FIG. 1, FIG. 3 is a front view taken longitudinally of a modification of the embodiment shown in FIG. 1, and FIG. FIG. 5 is an explanatory diagram showing the positional relationship between the thread guide and the bobbin shaft, and FIG. This shows the winding condition of the bobbin when the bobbin thread is long. FIG. 5(b) shows the bobbin thread winding state when the distance between the thread guide and the bobbin winding shaft is short, and FIGS. 6(a) and 6(b) show the thread feeding state of the thread guide. FIG. 2 is an explanatory diagram schematically showing the length of a yarn supply path from position o to the light take-up axis of the bobbin thread bobbin. 16... Thread 18... Thread spool 20...
Thread guide 22... Thread winding shaft 24... Lower thread bobbin 24, 24c... Flange 28... Cam body FIG, 6 (a) FIG, 6 (bl FIG, 3 U 16... Thread 20...thread guide body 2-2...bobbin winding shaft 24...bobbin thread bobbin 24, 24c'', flange 28...cam body

Claims (1)

[Scope of Claims] [1] Winding the thread (16) supplied from the thread spool (18) via the thread guide member (20) onto the bobbin thread bobbin (24) inserted into the thread winding shaft (22). In the bobbin thread winding device for mounting, the length of the thread supply path from the thread guide (20) to the bobbin thread bobbin (24) inserted into the bobbin thread bobbin (22) is the same as that of the bobbin thread bobbin (24). A cam body (28) is provided for setting the length of the yarn supply path so that the length of the yarn supply path is approximately equal no matter where the yarn (16) is wound up between the flanges (24b, 24c). Due to the engagement of the thread (16) supplied to the bobbin thread bobbin (24) with the cam body (28), the bobbin thread bobbin (24)
) is made equal between both flanges (24, 24c) of the bobbin thread winding device. [2] The thread guide (20) is configured such that the thread delivery position (0) from the thread guide (20) is at the same position in the axial direction of the thread winding shaft (22), and the cam body (28)
2. The bobbin thread winding device according to claim 1, wherein the cam surface (28a) of the thread guide member (20) is formed into an arcuate surface centered on the thread delivery position (0) of the thread guide member (20). A device for equalizing the diameter of the bobbin winder. [3] A bobbin winder for a bobbin thread winding device according to claim 1, wherein the cam body (28) is configured to be adjustable in position with respect to the bobbin winding shaft (22). Diameter equalization device.