JPS59137094A - Needle yarn feeder 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 This invention uses a three-tube holding means that can hold and release needle thread, and a feeding body that is disposed on the needle thread path between both holding means and operates in synchronization with the thread take-up. At times other than when the needle thread is tensioned by the thread take-up, the holding means on the supply source side is opened and the holding means on the take-up side is closed, increasing the needle thread path between both holding means, allowing the needle thread to be paid out from the supply source, and then When the amount of needle thread is paid out, the holding means on the supply source side is closed to prevent further feeding, and the holding means on the thread take-up side is opened to hold the fed-out needle thread in both directions as the thread take-up rises. - Actively feed out the necessary length of needle thread from the supply source for each stitch formation and supply it to the thread take-up, and in particular, operate the sewing machine in a state where the sewing machine needle is located below the top surface of the bed. When the sewing machine stops and the presser foot is raised, both holding means remain in the state before the sewing machine stopped, and when the sewing machine is stopped and the presser foot is raised with the sewing machine needle positioned above the top surface of the bed, both holding means are left in the state before the sewing machine stopped. In a type of needle 4 Q feeding device that is open (type 4), detection of the timing to open the holding means on the supply source side and detection of the period during which the sewing machine needle is located below the top surface of the bed are related to the rotation of the main shaft. The purpose is to simplify the control circuit of this type of device by using a common position signal generated from a sewing machine detection device.Embodiments of the present invention will be described below with reference to the drawings. 1 is a main shaft (not shown) that rotates in conjunction with the drive source.
A needle bar 3 has a needle 2 with a needle thread T fixedly running at its lower end and moves up and down in conjunction with the main shaft. This is a known device that includes a thread take-up 5 that reciprocates between two positions in conjunction with the main shaft to tension and relax the thread T, and the relationship between the needle bar 3 and the thread take-up 5 with respect to the rotation angle of the main shaft is determined by the third As shown in the figure.

The first holding means 6 and the second holding means 7 include a balance 5 and a bobbin 4.
The electromagnet (first solenoid) 8 and the electromagnet (second solenoid) 9 are arranged at a distance from each other on the needle thread path between the bobbin spool 4 and the needle thread take-up 5 in the needle thread supply direction. , a pair of holding plates 10 and 11 which immovably clamp the needle thread T when energized and movably release the needle thread T when de-energized.

The feeding body 12 has an eccentric cam 13 that rotates in conjunction with the main shaft.
The free end of the holding means 6 and 7 is arranged in relation to the needle thread path between the two holding means 6 and 7, so that the needle 2 is positioned below the bed surface as shown in FIG. The needle 2 and thread take-up 5 are moved to increase the needle thread path between the two holding means 6 and 7 when the needle is located at the lower stop section (lower stop section), and to minimize the length of time until the thread take-up is tensioned by the thread take-up 5. to relate to.

Further, once the needle thread T moves along its path, the rotating body 15 is rotatable in proportion to the moving distance of both the holding means 6,
It is placed between 7.

Regarding the electric circuit, the feed-out detection device 16 generates a pulse of Ill every time the rotating body 15 rotates by a certain angle. The main shaft detection device 17 is arranged in relation to the main shaft or a part linked thereto, and detects a specific rotation angle of the main shaft corresponding to the period when the needle 2 is located below the bed surface, and detects a low level (hereinafter referred to as ) generates a position signal. The presser foot lift switch 18 is arranged in relation to the movement path of a known presser foot that supports a presser foot at its lower end.
A high level signal (hereinafter referred to as ■) is generated in connection with raising the presser foot to a specific position by appropriate means. Drive switch f1G is a drive circuit of sewing machine 1 (not shown)
2 digits, and generates an H signal when the spindle is stopped.

The counter 20 is reset by a position signal from the spindle detection device 17 and counts pulses from the feeding detection device 16. The setting device 21 is a digital setting device using a dial.
It consists of a switch that sets the length of the needle thread T to be fed out in accordance with the length of the needle thread T required for stitch formation (which varies depending on conditions such as the thickness of the fabric, the swing width of the needle, and the feed pitch). It generates different digital codes depending on the set length. This digital code is related to the number of clock pulses from the payout detection device 16 which corresponds to the rotation angle of the rotating body 15 which is proportional to the payout amount.

The comparator circuit 22 compares the output values of the counter 20 and the setting device [21], and when they match, generates a match signal of the hammer H. The flip-flop FF is reset by the position signal from the spindle detection device 17 to set the Q terminal output to L, and the Q terminal output is inverted from L to H by the coincidence signal from the comparator circuit 22. Operation - The wrs 23 and 24 receive the (2) signal to energize the first solenoid 8 and the second solenoid 9, and receive the L signal to demagnetize and close them.

The timer TMI is composed of a mono-staple malte biflator, and detects the fall of the L signal (position signal) from the spindle detection device 17 to generate a pulse. The timer TM2 consists of a capacitor C and a[R, and receives a pulse from the timer TMI via an amplifier B'4-, and from that time until a certain period of time has elapsed, the comparator P outputs the ■ signal. The output is set to be operable in step 5.

In addition, 01 to G- are AND gate circuits, ■ is an inverter, and presser foot lifting switch f18. Drive switch f1G
and Goo) Gl constitutes the holding star detection device 25,
When the presser bar is raised to a specific position while the sewing machine is stopped, a thread loosening signal is generated. Next, these effects will be explained.

When the presser foot is lowered and the Mi V71 is driven, the output of the presser foot star detection device 25 becomes L, so gooo) (C.

G4 is opened and outputs the output state of the flip-flop FF as it is, and in conjunction with the main shaft, the needle bar 3, take-up lever 5, and feed-out body 12 move along the needle bar curve, take-up lever curve, and feed-out curve in FIG. It moves back and forth. The forward movement of the feeding body 12 in the counterclockwise direction in FIG. 1 increases the needle thread path between the two holding means 6 and 7. Since the flip-flop FF is reset by the signal (2) from FF and its Q terminal output is L, the output of G1) is high, and the output of G43 is H. Also, when the main shaft is rotating at a predetermined speed or higher, the output of the comparator P becomes ■ as described later, so at the above main shaft @ rotation angle position, the first solenoid 8
is demagnetized and the second solenoid 9 is energized.
The needle thread T is fed from the bobbin winder 4 between the holding means 6 and 7 by the length of the needle thread path increased by the forward movement of the needle thread T. In this way, the rotating body 15 rotates in conjunction with the needle thread, -r, being paid out from the bobbin winder, and as a result, a number of clock pulses proportional to the rotation angle are generated from the winding detection device 16. do.

This clock pulse is converted into an HF number by a counter 2o, and the calculated value is input to the 10,000 input section of the comparator circuit 22. When the calculated value of the counter 20 matches the output of the setting device 21, a match signal of H is output from the ratio V@path 22, and as a result, the output of the flip-flop FFf)Q terminal is inverted from the aforementioned L to H. One solenoid 8 is energized and the second solenoid 9 is demagnetized.

Therefore, after the needle thread T of a predetermined length is fed from the bobbin 4 between the two holding means 6 and 7 by the forward movement of the thread body 12, the first holding means 6 clamps the needle thread T so that it cannot pass through. The second holding means 7 releases the needle thread T so that it can pass through. Moshimo payout body 12
If the needle thread T of a predetermined length is paid out during the forward movement, the needle thread T loosened between the needle 2 and the second holding means 7 is moved between the needle 2 and the second holding means 7 during the subsequent forward movement of the feeding body 12. It will be brought back in 7 days.

Further, the feeding body 12 returns to its original position until the needle thread T is next tensioned by the thread take-up 5. Therefore, during the next needle thread tensioning period using the thread take-up lever 5, the needle thread T is fed between both holding means 6 and 7.
is pulled out as the thread take-up lever 5 rises, and the thread holder R6 and the needle thread T between the stitches are tensioned, thereby tightening the stitches to the planned strength and knotting them. ◇ Sewing machine 1 is stopped. When the presser foot is raised, the output of the presser foot detection device 25 becomes H and G2 is opened. G3.
Since G4 is held in the open state, even if the sewing machine is stopped, if the needle thread T is in the middle of being fed out by the feeding body 12 and the needle thread T is moved by an external force to the image holding means 6, 7.
Even if the needle thread T of the predetermined length set by the setting device [1121] is fed between the image holding means 6 and 7, if the output of the flip-flop FF is reversed to H. , the way the gates Gl and 04 come out is also reversed, so that the first holding means 6 prevents the needle thread from being drawn in thereafter, and if the presser foot is lowered again and the sewing machine is driven, it will continue to start from that state. do. That is, in the lower stop section, when the sewing machine is stopped and the presser foot is raised, an external force acts on the needle iT and does not have any effect on the needle thread I41 being drawn out for each stitch.

On the other hand, if the sewing machine is stopped during the lower stop section where needle 2 is located above the bed surface and the presser foot is raised to a predetermined position, the output of gate G2 becomes H.
When Gll and G4 are closed, their outputs become L and both solenoids 8 and 9 are demagnetized, so both holding means 6,
7 releases the needle thread T so that it can pass through, making it easier to take out the cloth in this case.

As mentioned above, while the sewing machine is running, both solenoids 8,
9 is controlled, but when the sewing machine is stopped, the timer TMI
Since the input of the comparator P does not change, the output of the comparator P becomes L after a predetermined time period determined by the time constant of the timer TM2 has elapsed.

This results in game) G5. Since G6 is closed, both solenoids 8 and 9 are demagnetized, preventing overheating while the sewing machine is stopped.

As described above, the present invention uses a three-tube holding means that can hold and release the needle thread, and a feed-out body that is arranged on the needle thread path between the image holding means and operates in synchronization with the thread take-up. At times other than the needle thread tension period, the holding means on the supply source side is opened and the holding means on the balance side is closed, and the needle thread path between the image holding means is increased to let out the needle thread from the supply source. When a predetermined amount of needle thread is paid out, the holding means on the supply source side is closed to prevent further feeding, and the holding means on the thread take-up side is opened to allow the needle thread that has been paid out to be held on both sides as the thread take-up rises. The needle thread of the required length is actively paid out from the supply source each time a stitch is formed, and supplied to the thread take-up so that the needle thread is pulled out from the holding means. When the sewing machine is stopped and the presser foot is raised, both holding means remain in the state they were in before the sewing machine stopped, and when the sewing machine is stopped and the presser foot is raised with the sewing machine needle positioned above the top of the bed, both holding means are In a needle thread supply device of the type shown in FIG. Since this is done using a common position signal generated from a simple detection device, the control circuit of this type of device is simplified and costs are reduced, and the probability of failure of the entire device is reduced and reliability is improved. It has the effect of improving

In each of the above-mentioned embodiments, basic data regarding the length of needle thread required for tying each needle is set by manual operation of a digital switch. The pre-stored yarn amount data is read out from the storage device based on the data detected by a known detection means to detect the set position or the data detected by the momentum of the needle swing mechanism or cloth feed mechanism, and this data is used as the basic data for the unreeling length. Alternatively, the data calculated based on the detected data may be inputted to the comparator circuit 72 as the basic data of the feeding length, or the needle swinging mechanism may be inputted based on the data stored in the storage device. In a sewing machine of a type that operates a fabric feed mechanism or a fabric feeding mechanism, the yarn amount data stored in advance is simply read out using the stored data, or the data obtained by calculation using the stored data is used as the basic data for the unreeling length by a comparison circuit/ It is also possible to input it to l.

In addition to data on needle swing and fabric feed, Ichihara also collected detection data from a heavy weight detection means that uses a potentiometer to detect changes in the position of the presser foot, as well as pre-experiment data based on the type of fabric, such as yarn and weaving method. The feeding amount may be set by combining the data obtained by.

Further, in the above embodiment, the feeding body /2 is linked to the cam body /3, but as shown in the first embodiment of Japanese Patent Application No. 37-g, 2'/7.2, the needle thread path is A feeding body having a cam surface formed on the outer periphery facing the may be rotated.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the main parts, Figure 1 is a block of the electrical circuit,
Figure, 3rd. The graph is a time chart. Name of applicant: Tokyo Heavy Equipment Industry Co., Ltd. Procedural amendment (method) 1. Indication of case: 1982 Patent Application No. 13082 2. Name of invention: Sewing machine needle thread supply device 4. Date of amendment order: April 26, 1988 5,
All drawings to be corrected 590-

Claims (1)

[Scope of Claims] The thread take-up lever and the needle thread supply source are arranged so as to be spaced apart from each other on the needle thread path in the forward and front directions in the needle thread supply direction. first and second holding means B, 7 which act on the needle thread so as to allow the thread to pass; and a first holding means B, 7 arranged on the needle thread path between both the holding means and changing the needle thread path between the two holding means; A feeding body that operates in synchronization with the thread take-up so that the length of the path increases at a time other than when the needle thread is tensioned by the thread take-up and then becomes the shortest by the time the thread thread is tensioned at maximum by the thread take-up; The actuation of the feed-out body or the pay-out length of the needle thread by the feed-out body which engages the needle thread in the needle thread supply direction before the feed-out body and is proportional to the increase in the length of the needle thread path between both holding means. A feed-out detection device/B which is displaced in proportion to the amount of displacement and generates electrically different thread amount detection signals in accordance with the amount of displacement, and a main shaft which is arranged in relation to the main shaft and corresponds to the time when the sewing machine needle is located below the top surface of the bed. The spindle detection device detects a specific rotation angle and generates a position signal, and can generate a setting signal corresponding to the length of needle thread required to form one stitch in response to different sewing conditions. A setting device, a presser foot that always has a downward elastic force and can be locked and moved up and down to press and release the fabric against the bed and surface, and a thread that moves in relation to the rise of the presser foot. A presser foot star detection device 23' that generates a loosening signal, a comparison circuit 22 that compares the thread amount detection signal and a set signal and generates a matching signal when they match, and a presser foot star detection device 23' that generates a loosening signal; The first holding means is activated and the second holding means is deactivated, and both holding means are activated and deactivated during the period from the generation of the position signal to the generation of the coincidence signal.
A needle thread supply device for a sewing machine, comprising: a control circuit that reverses the inactive state and controls both holding means to be inactive in relation to a thread loosening signal except during a period in which a position signal is generated.