JPS5937984A - Needle yarn supply apparatus 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 two-rod holding means that can hold and release the needle thread, and a feeding body that is disposed on the needle thread path between the two holding means and operates in synchronization with the thread take-up. When the needle thread is loosened by the thread take-up, the needle thread path between the two holding means is increased by the feeding body with the holding means on the supply source side open, and the needle thread is paid out from the supply source side, so that a predetermined amount of needle thread is paid out. In connection with this, the holding means on the supply source side is closed to prevent subsequent feeding, and when the thread take-up is tensioning the needle thread, the holding means on the balance side is opened while the holding means on the supply source side is closed. This type of needle thread supply device draws out the needle thread of the length required for each stitch formation from a supply source and supplies it to the thread take-up by drawing it out from between both holding means as the thread take-up rises. In particular, when the presser foot is raised while the sewing machine is stopped, the gripping of the needle thread by both holding means is released, and the purpose is to facilitate the thread hooking operation and the removal of the fabric from the sewing section of the sewing machine. do.

Embodiments of the present invention will be described below with reference to the drawings.

Regarding the mechanical configuration, the sewing machine is not shown in detail, but it has a main shaft that rotates in conjunction with a drive source, a needle bar that fixes the sewing machine needle with needle thread T and moves up and down in conjunction with the main shaft, and a needle thread supply. It supports the needle thread T between the bobbin spool and the sewing machine needle, and is linked to the main shaft so that the needle thread T is repeatedly tensioned and relaxed. This is a well-known device equipped with a balance 1 that reciprocates between three positions according to a curved line.

The holding means 2 and 3 are arranged on the needle thread path between the thread take-up thread take-up and the thread take-up lever 1 at a distance from each other in the direction of supplying the needle thread from the thread take-up thread take-up to the thread take-up thread take-up L, and are connected to electromagnets ( S
QL, 1) 4 and electromagnet (SQL, 2) 5, and a pair of holding plates 2α that are joined by excitation and separated by de-excitation.

It consists of 2hl, 3c, and 3A, and when these holding plates are joined, they immovably clamp the needle thread T, and when they are separated, they movably release the needle thread T.

The guide plates 6, 7 are spaced apart from each other on both sides of the needle thread path between the two holding means 2, 3, and are fixedly arranged vertically, and have openings 6α, 7α formed therebetween, respectively. A long groove 8α is formed in the upper part 8 of the sewing machine frame so as to face the gap between the guide plates 6 and 7.

The feeding body 9 includes a swinging body 11 rotatably supported at an intermediate position on a shaft 10 fixed to the machine frame, and a swinging body 11 rotatably supported on an upper part of the swinging body 11 about a shaft 12 parallel to the workpiece 0. , and the coil spring 19g stretched between the oscillating body 11 and the oscillating body 11 is always fed out with an elastic force applied in the clockwise direction in FIG. It consists of an arm 14 and an opening 6 a of both guide plates 6 and 7.
, 7α. As shown in FIG. 4, the feeding arm 14 has an upper end surface 14α inclined downward to the right to form a T-shape at the upper part thereof, with the right corner serving as a thread hooking part 14A. In addition, as shown in FIG. 3, when the needle thread T is relaxed by the thread take-up 1, the feeding body 14 bends and increases the needle thread path between the two holding means 2 and 3. In order to prevent the needle thread path from being bent during the tension period of T, the follower 11A provided at the lower part of the rocking body 11 is connected to the machine frame with respect to the cam surface 15α of the cam body 15 that rotates in synchronization with the thread take-up 1. The tension of the needle thread T is set to be lower than the tension of the needle thread T when both the holding means 2 and 3 pinch the needle thread T while the thread path stretched between them is bent, and the coil spring 16
Please set it stronger than coil spring 13.

The paste tension 17 is disposed between the bobbin winding and the holding means 2 so as to always provide a constant passage resistance to the needle thread T. The rotating body 18 is disposed between the holding means 2 and 3 so as to be rotatable in proportion to the amount of needle thread T that is fed out from the bobbin winding in conjunction with the operation of the feeding body 9.

The paste tension 19 as a resistance applying device is similar to the paste tension 17.

Regarding the configuration of the electric circuit, the thread cutter switch 23 is used to give an operation command to a thread cutter for cutting the needle thread and yarn connected to the seams formed on the cloth below the sewing machine bed. The high level (hereinafter referred to as H) signal related to the operation of the control lever is tB.
-To force. The drive switch 24 is provided in the drive circuit of the sewing machine, and outputs an H signal when the sewing machine is stopped. The presser foot lift switch 25 is arranged in relation to the movement path of a known presser foot bar having a presser foot fixed to its lower end.
An H signal is output in connection with raising the presser bar to a specific position by operating the presser foot lifting lever or by using an appropriate presser foot lifting means. The delay circuit 26 outputs the input signal after a certain period of time has elapsed.

The feed-out detection device 27 generates one pulse every time the rotating body 18 rotates by a certain angle. The position detection device 28 is arranged in relation to the main shaft, and includes a section A that detects the rotation angle of the main shaft at which the previous stitch knotting is completed and the balance 1 begins to descend and generates a position signal H, and a section A that generates a position signal H, and a section B that detects the rotation angle range from just before the needle thread relaxation period starts to just before the end of that period and generates a position signal H.

The counter 29 is reset by a position signal from part A of the position detection device 28 and counts clock pulses from the feedout detection device 27. The setting device 30 consists of 7 digital switches set by a dial, and is set according to conditions such as the length of the needle thread T required for stitch formation, the thickness of the cloth, the swing width of the needle, and the feed pitch. The length of the needle thread T to be fed out is set, and a different digital code is generated corresponding to the set length. This digital code is related to the number of four pulses from the pay-out detection device 27 corresponding to the degree of rotation angle of the rotating body 18 which is proportional to the pay-out amount.

Comparison circuit 31 compares the output values of counter 29 and setting device 30, and generates an H match signal when both match. The operating circuits 32 and 33 receive the H signal and operate the electromagnets 4 and 5.
The circuit is opened so that the electromagnet 4.5 is energized, and the circuit is closed so that the electromagnet 4.5 is demagnetized in response to a low level signal.

The flip 70 knob FF is reset by the position signal from the A section of the position detection device 28 and outputs Q#-P, which is L.
The match signal from the comparison circuit 31 inverts the Q terminal output from L to H.

Note that Gl, G2. G8 is an AND gate circuit; G4 is an OR gate circuit; 1 rises to tension the needle thread T between the holding means 3 and the needle or stitch, and then descends to relax it, and these steps are repeated. Further, during the above-mentioned needle thread relaxation period by the thread take-up 1, the swinging body 11 of the feeding body 9 moves clockwise in FIG. Return.

When the rocking body 11 moves forward, the extending arm 14 also releases the coil spring 1.
It moves together with the rocking body 11 due to the elastic force of 3, and bends the needle thread T between the opening holes 6α as shown in FIGS. increase. Note that during this period, the FF is
is reset and the output of section B is H, so one electromagnet 4 is demagnetized and the other electromagnet 5 is energized,
As a result, the holding means 2 on the supply source side releases the needle thread T, and the holding means 3 on the feeding side clamps the needle thread T so that it cannot pass through.As the swinging body 11 (feeding body 9) moves forward, the A length of needle thread corresponding to the increase in path is unwound from the spool between the holding means 2, 3.

When the needle thread T is paid out from the bobbin spool by the above action, the rotating body 18 rotates counterclockwise in FIG. 1, thereby causing the payout detection device 27 to generate a number of clock pulses proportional to the rotation angle. This clock pulse is counted by a counter 29, and the calculated value is inputted to one input section of a comparator circuit 31. The calculated value of the counter 29 is set by the setting device 3.
When the output matches the output of 0, the comparison circuit 31 outputs a match signal of H, which inverts the Q terminal output of the FF from L to H, so the electromagnet 4 is energized and the holding means 2 prevents the needle thread T from passing through. This prevents the needle thread T from being drawn out from the spool. At this time, the other holding means 3 is the position detecting device 2.
Since the output of No. 8 does not change, the needle thread T is continued to be clamped. Therefore, after the needle thread T of the length set by the setting device 30 is let out from the bobbin, the needle thread T is
If this happens during the forward movement of the rocking body 11, the tension of the needle thread T between the holding means 2 and 3 will cause the coil spring 13 to move forward when the rocking body 11 moves forward. After being stretched, the feeding arm 14 remains at that position, and the feeding of the one-needle thread T is completed.

Next, during the period from just before the start of the tension period of the needle thread T by the 1 balance 1 to just before the start of the relaxation period of the needle thread T, the position detection device 28
Since the output of the section becomes L, the electromagnet 5 is demagnetized, but since the electromagnet 4 continues to be excited via the gate G2, the holding means 2
holds the needle thread T, and then the holding means 3 releases the needle thread T.

Therefore, during this period, the needle thread that has been let out between both holding means is pulled out as the thread take-up 1 rises, tensioning the holding means 2 and the needle thread T between the stitches, and thereby tightening the stitches. Nodules.

Thereafter, the above operation is repeated every time the balance 1 makes one reciprocation.

While the sewing machine is stopped, the output of the drive switch 24 is H.
Since the gate GJ is opened, if the presser foot lift switch 25 is closed (turned on) while the sewing machine is stopped, the gate G4.
The electromagnet 4 is demagnetized via G3 (demagnetized, then the delay circuit 26 and gate) after a certain period of time has passed via G2. Therefore, if you raise the presser foot while the sewing machine is stopped,
After a certain period of time after the holding means 3 releases the grip on the needle thread T, the holding means 2 releases the grip on the needle thread T. Also, when the thread trimming device is activated, the output of the thread trimming switch 23 is used to
4. After the electromagnet 5 is demagnetized via G8, the delay circuit 26
The electromagnet 4 is demagnetized via the holding means 3 releases the needle thread T in the same manner as when the presser foot is raised, and then the holding means 2 releases the needle thread T.

In this example, basic data regarding the length of needle thread required for tying each stitch 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 the set position of the needle by an appropriate detection means or the data detected by the movement of the needle swing mechanism or cloth feed mechanism, and this data is used to determine the unreeling length. Comparison circuit 3 uses data calculated based on the detected data as basic data for the feeding length.
1.In a sewing machine that operates the needle swing mechanism or cloth feed mechanism based on the data stored in the memory device, the thread amount data stored in advance can be simply inputted using the stored data. Data obtained by reading out or calculating from the stored data may be input to the comparison circuit 31 as basic data of the feeding length. In addition to data related to needle swing and fabric feed, we also include detection data from a heavy weight detection device that uses a potentiometer to detect changes in the position of the presser foot due to heavy weight, as well as pre-defined data based on the type of fabric, such as yarn and weaving method. Composite the data obtained through experiments 2. The amount of feeding may be set.

Therefore, we have shown a type in which the feeding operation of the feeding body is stopped by the tension of the needle thread between them, but as in the one described in the first embodiment of Japanese Patent Application No. 57-8'2712, it is possible to A feeding body that constantly rotates in synchronization is arranged between the image body holding means, and when the needle thread is relaxed by the thread take-up, the needle thread path between the image body holding means is fed out while the holding means on the supply source side is open. Increased by the body and paying out needle thread from the source,
When the predetermined amount of needle thread has been paid out, the holding means on the supply source side is closed, and at the same time, the holding means on the balance side is opened to stop the subsequent feeding, and at the same time, the needle thread thread take-up is stopped by the thread take-up in this state. It may also be applied to a type of device in which the amount of needle thread that was previously paid out during the tension period is pulled out from both holding means as the thread take-up rises. The supply source means is closed when the needle thread is loosened by the thread take-up, by means of a two-part holding means and a feed-out body disposed on the needle thread path between the image body holding means and operating in synchronization with the thread take-up. In addition to preventing the needle thread from being fed out thereafter, when the thread take-up is tensioning the needle thread, the holding means on the thread take-up side is opened while the holding means on the supply source side is closed, and the thread taken out first is held in place as the thread take-up rises. In a needle thread supply device of the type that feeds the required length of needle thread from the supply source to the thread take-up for each stitch formation by drawing out σ1 from between the means, it is possible to prevent the lifting of the presser foot when the sewing machine is stopped. The configuration includes a presser foot star detection device that generates a thread loosening signal in conjunction with the thread loosening signal, and a control circuit that controls both holding means to be inactive in response to the thread loosening signal. If you raise the presser foot after the work is completed, you can manually pull out the needle thread from the needle thread supply source, so you can easily take out the sewn fabric from the sewing machine seam by just slightly tensioning it by σ1. Hanging has excellent effects on workability, such as making work easier.

[Brief explanation of drawings]

Fig. 1 is a perspective view of the main parts, Fig. 2 is a block diagram of the electric circuit, Fig. 3 is a time chart, and Figs. 4-5 are explanatory views of the operation. Patent applicant name Tokyo Heavy Equipment Industry Co., Ltd.

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. A force that acts on the needle thread so that it can pass through the needle.
2, disposed on the needle thread path between B and both holding means,
The needle thread path between both holding means is changed so that the length of the path is increased at a time other than when the needle thread is tensioned by the thread take-up, and then synchronized with the thread take-up so that it is made as short as possible by the time when the needle thread is tensioned at its maximum by the thread take-up. The needle thread is engaged with the feeding body 9 which is operated by the feeding body, and the needle thread is related to the feeding body or is located before the feeding body in the needle thread supply direction.
The actuation of the feeding body is proportional to the increase in the length of the needle thread path between both holding means, or the needle thread is displaced in proportion to the length of the needle thread fed out by the feeding body, and electrically detects the amount of thread that varies depending on the amount of displacement. A feed-out detection device 27 that generates a signal and a main shaft (
A position detection device 2 which is arranged in a related manner and generates a position signal by detecting a specific rotation angle of the main shaft corresponding to the needle thread relaxation timing by the thread take-up.
8, and a setting device 3 capable of generating a setting signal corresponding to the length of needle thread required to form one stitch in response to different sewing conditions.
0 and 1, it always has a downward elastic force and presses the cloth against the top of the bed.
A presser foot that can be moved and locked up and down so as to be released, a presser foot star detection device 34 that generates a thread loosening signal in connection with the rise of the presser foot when the sewing machine is stopped, and a thread amount signal and a setting signal. It has a comparator circuit 31 which generates a match signal when they match, and the first holding means, which is located before the feeding body in the direction of supplying the needle thread, is always kept inactive and acts in relation to the match signal, and the balance after the position signal after the end of the needle thread tension period (with respect to the strain effect) and the second holding means is always activated and inactive in relation to the position signal before the start of the needle thread tension period by the balance. A control circuit G2.G8.FF, 32, 33 that operates before the start of the needle thread relaxation period and controls both holding means to be inactive in relation to the thread relaxation signal.
A sewing machine needle thread supply device equipped with , and.