JPS61213090A - Bobbin thread residual amount detector of sewing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Field of Application) The present invention relates to a device for detecting the remaining amount of bobbin thread in a sewing machine, and exhibits its useful value in replenishing consumed bobbin thread during sewing work on a sewing machine. do.

(Prior Art) Conventionally, a technique as shown in FIG. 5, disclosed in Japanese Patent Publication No. 57-40800, is known as a device of this type.

That is, when the remaining amount of bobbin thread on the bobbin 12 inserted into the bobbin case 11 in the figure becomes small, the thread detector 13 is moved to the left (indicated by the dotted line) in the figure by the thread detector spring 14 via the bin 13a. ).

In conjunction with this movement, the detected object 15 is similarly displaced to the position shown by the dotted line on the left. Due to this displacement, the distance from the detector 16 becomes narrower, and the detector 16 operates to issue an alarm for bobbin thread consumption.

(Problems to be Solved by the Invention) In the above-mentioned conventional device, a guide groove is provided in the collar and shaft of the bobbin, a detection body is inserted between the bobbin case and the shaft of each bobbin, and the bobbin case is covered with a guide groove. A detection body had to be installed, and a large number of such parts and their ancillary parts were required. Therefore, a special dedicated bobbin and bobbin case were required, and it was impossible to immediately use a general type of bobbin. there were.

In addition, there were also inconvenient problems in terms of production, cost, etc.

The present invention enables the use of general type bobbins and bobbin cases, and is intended to solve the above-mentioned problems encountered in the prior art.

[Structure of the invention]

(Means for Solving the Problem) As a means for solving the above problem, the present invention includes a detector (a diffused light type photocoupler, which is a photodiode and (composed of a phototransistor).

Then, due to the reflection action on the bobbin side due to the detected amount of emitted light,
The detector itself directly detects the bobbin thread consumption state and issues an alarm.

(Function) When the thread is sufficiently wound around the bobbin (general bobbins have multiple holes arranged in an arc shape on the flange surface), the light emitted from the photodiode is emitted by the rotation of the bobbin during sewing by the sewing machine.
The phototransistor's output has little voltage fluctuation because it is reflected on the flange surface and the thread that closes the hole. When the bobbin thread is consumed and the amount of winding thereof moves inward from the punching hole and the punching hole becomes a threaded state, the light emitted from the photodiode is not reflected at the punching hole portion and cannot be received by the phototransistor. Therefore, the voltage fluctuation becomes large, and the signal pulse generated in the detection circuit becomes
The signal is input to the control circuit and an alarm is issued.

(Embodiment) Fig. 1 shows a diffused light type photocoupler attached to a horizontal hook type sewing machine (consisting of a photodiode and a phototransistor).

Reference numeral 3 denotes a known bobbin having a punch hole 3a in the flange, and the flange reflects incident light. 4 is an inner pot into which the bobbin 3 is inserted; 5
is the outer hook, and 6 is the bobbin thread wound on the bobbin.

As shown in FIG. 1, when the bobbin thread 6 is sufficiently wound around the bobbin 3, the voltage fluctuation in the output of the transistor is small as shown in FIG. 3(a).

As shown in Fig. 2, when the bobbin thread 6 is consumed and its winding amount becomes inward from the bobbin's punch hole 3a, the voltage fluctuation increases, and an L shadow signal pulse is sent to the detection circuit as shown in Fig. 3(b). Occur. This signal is input to the control circuit and an alarm is issued.

In this example, an application to a horizontal hook type is illustrated, but if this is to be applied to a vertical hook type, it can be easily implemented by simply providing a notch at the corresponding location of the bobbin facing the detector. be able to.

〔Effect of the invention〕

During sewing work, to prevent defective products from occurring due to lack of bobbin thread, count the amount of thread wound on the bobbin in advance.
It is also conceivable to issue a warning when a predetermined amount has been consumed.

However, this method requires a device to count both the amount of winding and the amount of winding consumed, and only bobbins that have been counted cannot be used, and bobbins whose winding amount is unknown cannot be used.

The bobbin thread wound on the bobbin depends on the strength of the winding,
Due to uneven winding, etc., there is no guarantee that the remaining amount will remain constant at the time of the alarm. Furthermore, the amount of thread consumed varies depending on the type of product to be sewn and its material.

Therefore, counting the amount consumed is extremely delicate, and adjustments to accommodate various sewing-related conditions are also very difficult.

In the present invention, since the remaining amount of bobbin thread is detected without using a detection body, there is no need for a special bobbin, (bobbin case), etc., and a general item is sufficient. Further, there is no need for a pre-processing device for detection, and the remaining amount of bobbin thread can be detected simply by installing a detector, and the overall benefits brought about by this are very large.

[Brief explanation of drawings]

Fig. 1 is an explanatory sectional view of the device of the present invention in a state where the bobbin thread is sufficiently wound around the bobbin, Fig. 2 is an explanatory view of Fig. 1 when the remaining amount of the bobbin thread has decreased, and Figs. 3 and 4. 5 shows the output, frequency signals, and circuit diagram of the detector of the present invention, and FIG. 5 is an explanatory diagram of an example of a conventional device. 1...detector, 2...throat plate, 3...bobbin, 4...
...Inner hook (bobbin case), 5...Outer hook, 6...Bobbin thread f411 @31 @466

Claims (1)

[Claims] A sewing machine that detects the presence or absence of a bobbin thread wound around the bobbin using a photocoupler which uses the flange of a bobbin having a punched hole as a reflective surface and a phototransistor and a light emitting diode facing the bobbin. Lower thread remaining amount detection device.