JPS6132632Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a bobbin thread consumption sensing device for a sewing machine, especially a bobbin thread consumption detection device built into the sewing machine body that has a function of detecting in advance when the bobbin thread is finished being consumed. This relates to thread winding technology.

(Prior art) In sewing work, while the sewing machine is rotating, the bobbin thread to be used next is wound onto the bobbin by a bobbin thread winding device. After removing the empty bobbin, you can proceed with the work by replacing it with a bobbin that has been wound with bobbin thread, or use a separate bobbin winder etc. to automatically wind a predetermined number of bobbins onto the bobbin and store them. I use it by replacing it every time it is used up.

However, in the past, there was no means to detect when the bobbin thread ran out in the machine itself, that is, when to replace the bobbin, and with this, the operator relied only on his/her own intuition, and the operator did not know when the bobbin thread was running out. If this is continued, it will become a state of empty stitching and the work will have to be restarted, which will not only greatly reduce work efficiency but also cause a number of problems such as damage to the fabric due to needle holes.

In conventional bobbin thread winding devices, the spindle of the bobbin pulley is directly connected to the bobbin thread winding shaft, and since the bobbin thread winding shaft rotates at the same speed as the bobbin winding pulley, the bobbin rotates at high speed, and the bobbin thread winding up in a short period of time.

If the bobbin thread is wound at high speed in this way, the winding time will certainly be shortened, but the winding speed is determined by the speed at which the bobbin thread is paid out from the bobbin built into the sewing machine body. This is done without any relation to the consumption and payout amount of the bobbin thread, and has only the function of winding the bobbin thread.

(Purpose of the invention) The present invention not only has a bobbin thread winding function, but also mechanically synchronizes the time when the bobbin thread winding operation ends and the time when the bobbin thread runs out in the sewing machine itself. The present invention provides a bobbin thread consumption sensing device that can predict the bobbin thread consumption of a sewing machine body in advance based on the end time of picking work, and is particularly easy to install on ready-made products. The object of the present invention is to provide an inexpensive bobbin thread consumption sensing device.

(Structure of the invention) That is, as a technical means to achieve this object, the present invention includes a thread winding pulley which inputs rotational power from the drive source of the sewing machine body, and a thread winding pulley which is interlocked with the thread winding pulley via a speed reduction mechanism. a bobbin thread winding shaft;
A control mechanism that stops transmitting power to the bobbin thread when a predetermined amount of bobbin thread is wound onto a bobbin attached to the bobbin thread winding shaft, and a bobbin thread feeder that consumes the bobbin thread in synchronization with the sewing of the sewing machine. This embodiment includes a deceleration mechanism that allows the winding amount to substantially match the winding amount of the bobbin thread.

(Function) Therefore, in the bobbin thread consumption sensing device of the present invention, since the bobbin thread winding speed is approximately equal to the bobbin thread payout amount of the sewing machine main body during sewing, the bobbin thread winding shaft stops. The time at which a predetermined amount of bobbin thread is wound onto the bobbin and the time at which the bobbin thread is fed out from the bobbin of the sewing machine body and the time at which the bobbin thread is consumed are approximately the same. The point at which the winding operation ends can be used as a guideline for when the sewing machine is about to run out of bobbin thread.

Hereinafter, an example of the implementation of the present invention will be illustrated and explained in detail.

Reference numeral 1 denotes a frame, which has opposing plates 2 and 3 provided vertically on a base, and is fixed on the surface of a table 4 of the sewing machine.

Reference numeral 5 denotes a thread-wound pulley, which is attached to the extending end of the input shaft 6 which is supported between the opposed plates 2 and 3, and which inputs rotational power by abutting the thread-wound pulley 5 against the drive belt P of the sewing machine main body. Become.

Next, reference numeral 7 denotes a bobbin thread winding shaft, and an arm 10 whose base end is pivotally attached 9 to the frame 1 via a bracket 8.
It is pivotally supported at the upper end of the body, and the tip serves as a bobbin attachment part.

Next, reference numeral 11 denotes a reduction mechanism which is formed between the input shaft 6 and the bobbin thread winding shaft 7. In this embodiment, a reduction shaft 12 is journalled between the opposing plates 2, 3 in parallel to the input shaft 6. A V-belt 15 is stretched between a small pulley 13 provided on the input shaft 6 and a large pulley 14 provided on the reduction shaft 12. A small gear 16 provided at one end of the reduction shaft 12 meshes with a large gear 17 provided on the bobbin thread winding shaft 7.

The reduction ratio of this reduction mechanism 11 is set so that the average speed of winding the bobbin thread by the bobbin thread winding shaft 7 is slightly faster than the average speed of winding the bobbin thread from the bobbin incorporated in the sewing machine body.

Next, 30 is a continuously variable transmission mechanism incorporated in the speed reduction mechanism 11, and a small pulley 13 is spline-fitted to the input shaft 6 with a pair of conical disks 31 and 32 facing each other.
Similarly, a large pulley 14 has a pair of conical discs 33 and 34 spline-fitted to the deceleration shaft 12 in an opposing state.
A transmission V-belt 15 having a trapezoidal cross section is stretched between the conical plates 3 of both pulleys 13 and 14.
Link 3 between 1 and 33 and between conical discs 32 and 34
5 and 35, and an adjustment screw 36 having left and right threads is provided between the links 35 and 35, and the adjustment screw 36 connects the conical disks 31 and 32 of both pulleys 13 and 14 and the conical cone through the links 35 and 35. Board 3
Both pulleys 13, 34 are moved closer to each other and separated from each other.
It is a continuously variable transmission mechanism using a variable diameter pulley that changes the effective diameter of 14.

Next, 18 is a control mechanism that connects a link 2 between a bracket 19 provided on the frame 1 and an arm 10.
0 and 21 are provided, and a stopper 22 is provided on the lower link 20 to restrict the bending movement of both links 20 and 21 in one direction when both links 20 and 21 are linearly expanded and contracted. 21 is provided with a detection piece 24 that comes into contact with the bobbin thread L and is pressed downward when a predetermined amount of the bobbin thread L is wound around the bobbin 23. The arm 10 is provided with a spring 25 that urges the gear 17 in a direction to separate from the small gear 16. Therefore, when a predetermined amount of the bobbin thread L is wound around the bobbin 23, the detection piece 2 is moved by the bobbin thread L.
As 4 is pushed downward, links 20 and 21
is bent from the central connecting pin 26, and at the same time, the arm 10 is rotated in the direction of arrow N by the biasing force of the spring 25, and as a result, the large gear 17 is disengaged from the small gear 16 and is directed to the bobbin thread winding shaft 7. The power transmission is stopped, and the bobbin thread winding shaft 7 is stopped.
Note that when winding a new bobbin thread L onto the bobbin 23 after replacing the bobbin, after attaching the bobbin 23 to the bobbin thread winding shaft 7, the links 20 and 21 are stretched linearly against the spring 25. If you let it, arm 10
returns to its original state, the large gear 17 and the small gear 16 mesh, and power transmission to the bobbin thread winding shaft 7 becomes possible.

Reference numeral 27 denotes a micro switch as a notification means, and when the arm 10 is rotated in the direction of arrow N due to the power stop operation of the control mechanism 18, a pin 28 extending from the bobbin thread winding shaft 7 comes into contact with the switch. is turned ON and a notification means (not shown) such as a buzzer or lamp is activated to notify the operator that the winding work is complete and that there is very little bobbin thread remaining on the bobbin attached to the sewing machine. It is something.

Therefore, in the bobbin thread consumption amount sensing device of this embodiment, the flower rotation speed of the bobbin thread winding shaft 7 is set by the deceleration mechanism 11 to be slightly faster than the bobbin thread payout amount of the sewing machine main body. The winding work of the bobbin thread L will be finished a little earlier than the bobbin thread is consumed, and the operator will be reliably notified of the end of the winding work by the notification means. By replacing the bobbin, accidents caused by empty stitching can be definitely prevented.

In addition, since the reduction ratio can be freely adjusted down to the minute level by the continuously variable transmission mechanism 30, the bobbin thread winding device can be used for general purposes, and the end of winding of the bobbin thread can be adjusted depending on the type of work. The timing between this and the end of the bobbin thread consumption can be adjusted.

Although an example of the implementation of the present invention has been described above with reference to the drawings, the specific configuration of the present invention is not limited to the above-described embodiment.

It is also possible to use a control mechanism that operates by detecting the winding amount of the bobbin thread with a counter, an electromagnetic clutch, or the like.

Further, although a notification means is not necessarily required, it is preferable to provide it as in the embodiment in order to ensure that the operator is aware of the completion of the winding operation.

(Effects of the invention) As explained above, according to the invention, the amount of bobbin thread consumed by the sewing machine can be detected based on the end of the bobbin thread winding operation, so that it is possible to detect the amount of bobbin thread consumed by the sewing machine body. Unlike conventional devices, it is possible to know when the bobbin thread has finished being consumed, and it is possible to prevent inconveniences such as empty stitching and improve work efficiency. As a result, the drive of the sewing machine body, which is the drive source for unwinding the bobbin thread, and the drive of the bobbin pulley are linked, and the bobbin thread winding amount is synchronized almost to the bobbin thread consumption via a speed reduction mechanism. Since the amount of bobbin thread consumed is sensed by the amount of bobbin thread taken up, the device of the present invention can be installed outside the sewing machine body in the same way as the conventional bobbin thread winding device.
Without the need for modification, it can be extremely easily installed on an existing sewing machine in a short time by simply replacing the conventional bobbin thread winding device with the device of the present invention. Since the device itself has a structure similar to that of a conventional bobbin thread winding device with a speed reduction mechanism and the like added, it can be provided at low cost and is highly practical.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a bobbin thread consumption sensing device according to an embodiment of the present invention, FIG. 2 is a side view of the bobbin thread consumption sensing device, and FIG. 3 is an explanatory view of the operation of the control mechanism. 5: Thread winding pulley, 7: Bobbin winding shaft, 11: Reduction mechanism, 18: Control mechanism, 23: Bobbin, 29:
Lower thread winding guide, 30: Continuously variable transmission mechanism, L: Lower thread, P: Drive belt.

Claims (1)

[Scope of utility model registration request] A thread winding pulley receives rotational power from the drive source of the sewing machine, a bobbin thread winding shaft is connected to the thread winding pulley, and a predetermined amount of bobbin thread is wound around the bobbin attached to the bobbin thread winding shaft. A control mechanism that stops power transmission to the bobbin thread winding shaft at a certain point in time, and a deceleration mechanism that makes it possible to substantially match the bobbin thread winding amount to the bobbin thread winding amount that is consumed in synchronization with the sewing of the sewing machine. A bobbin thread consumption sensing device for a sewing machine, characterized by comprising: