JPS5899991A - Method and apparatus for preventing damage of fabric due to ring knife - 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 In an overlock sewing machine equipped with a chain cutting device, the present invention provides an overlock sewing machine equipped with a chain cutting device, which uses a chain cutting upper scalpel even when the leading edge of the fabric at the start of sewing has an upward slope to the left. A method for automatically temporarily stagnation of a part of the fabric so as not to cause damage to the fabric, and then releasing the stagnation of the fabric after the ring cutting operation is completed, so that sewing can be performed without any hindrance, and the method thereof. This relates to the device.

Conventionally, during the sewing process using an overlock sewing machine equipped with a chain cutting device, in the case of a piece of fabric in which the old edge of the fabric is inclined in an upward left-hand direction toward the direction of travel at the beginning of sewing, the inclination is The upper scalpel was used to descend and come into contact with the leading edge sloping part a of the shaped fabric to cut the ring from the fabric, damaging the leading edge sloping part a.

However, in the present invention, the front edge inclined portion a at the sewing start of the fabric is
Detects when the ring cutting knife approaches the ring cutting knife for a certain period of time, activates the blocking member according to the order from the inspection department, and partially blocks the progress of the fabric at the inclined front edge a using the fabric progress blocking member. This prevents the slanted front edge a of the fabric from coming into contact with the upper knife even when the upper knife is lowered, so that the slanted front edge a of the fabric is not damaged. It is very effective.

Reference will now be made in detail to the accompanying drawings, which illustrate one example of carrying out the invention. Using a ring-cutting scalpel from 1, a shaft 3 fixed to the base end of the upper knife 1 so as to engage and rotate with a knife 2 as is known in the art is rotatably attached to the upper knife stand 4 as shown in FIG. 1. Pivotally supported,
An upper knife push spring 6 is interposed between the upper knife stand 4 and a collar 5 fixed to the shaft rod 3, and the upper knife 1 is pressed against the protrusion 7 of the lower knife 2. The thread cutting solenoid 8 device (not shown r) attached to the device rotates the shaft 3 and lowers the tip of the upper knife l, and the upper knife 1
It raises the tip. Reference numeral 9 denotes a light-receiving element made of a phototransistor, which is installed through the cloth sliding plate 11 on the side of the needle drop 10 slightly in front of the ring-cutting knife 1.2, and is attached to the light-receiving element mounting plate 12 on the bottom surface of the cloth sliding plate 11. It is something to do. Reference numeral 13 denotes a light emitting element consisting of an infrared and linear LED installed directly above the light receiving element 9, which is attached to a light emitting element mounting plate 15 fixed to the head 14 of the sewing machine main body. 16. 17 is a light receiving element 9 on the side of the needle drop 10 as shown in FIG.
Fabric advancement prevention members installed at a slight distance in front are fixed to the sewing machine body on the bottom surface of the fabric scrap board 11, respectively.
It consists of a fabric end stop rod 20 that is slidably supported on lower bearings 18 and 19, and is raised and lowered through a through hole 21 in a fabric sliding plate 110.
．． This temporarily prevents the process from proceeding to step 2. 22
A mounting base 2 is installed on the bottom surface of the sewing machine receiving plate 23 on which the 1-t sewing machine is installed.
4 is a fixed and attached rotary solenoid for raising and lowering the dough stop rod 20, and 25 is a rotary solenoid whose base end is connected to the rotary solenoid 2.
This is a solenoid arm fixed to the rotating shaft 26 of No. 2. Reference numeral 27 is a slotted hole drilled at the tip of the solenoid arm 25, and a pin 28 installed at the tip of the fabric edge stop rod 20 is inserted into the slotted hole 27.
In response to the signal transmitted from the fabric detector 16 via the control circuit, the swing motion of the rotary shaft 26 of the low clean lens 22 is converted into a linear motion of the stop rod 20, and the fabric is stopped. The rod 20 is moved up and down through the through hole 21 of the cloth sliding plate 11 as shown in FIG. 29.
Reference numeral 30 denotes a stop bar restriction collar fixed to the fabric end stop bars 20 at the upper and lower portions of the lower bearing 19, and the fabric sliding plate 1 of the stop bar 20
This is to adjust the appropriate protrusion to the upper surface of the cloth sliding plate 11 and sufficient embedding into the lower surface of the cloth sliding plate 11. Reference numeral 31 denotes a stop bar return spring interposed in the dough stop bar 20 between the upper bearing 18 and the L portion limiting collar 29, and when the lifting solenoid 22 of the stop bar 20 is turned off, the stop bar is returned. The rod 20 is buried in the lower surface of the cloth sliding plate 11. 32 is a paddle pulse generator that generates - pulses for each revolution of the sewing machine (that is, for each stitch 11); a magnet 35 is embedded in the side circumference of a disc 34 fixed to the main shaft 33 &C; 3
The magnetic sensing element 3B is attached to a sewing machine body receiving shelf 36 facing the sewing machine body 4 via an element mounting base 37. Next, the control circuit will be explained in detail. A comparator 39 is connected in series with the light receiving element 9 between the power supply Vcc and the ground, and compares the voltage of the volume 40 for adjusting the next comparison level with a preset voltage. The fabric detector 16 detects the fabric from the output (
When the fabric covers the light-receiving element 9 and blocks the light from the light-emitting element 13), the value becomes 0, and the fabric is not detected (the light-receiving element 9
The volume 40 is adjusted so that when the light from the light emitting element 13 reaches 1, the volume 40 becomes l. 42.43,
44.45 is the main output of the comparator lake-39, <-
This is a branch line that branches off via 1-41. 46 is a three-man powered NAND gate 47 and a two-man powered NAND gate 48 as the fifth
The input J pin of the flip-flop 46 is connected to the branch line 42 via the inverter 49, and the input pin is connected to a single person's cabin via the inverter 49. It is connected to the branch line 42 and branched through the four integration circuit 50 by CR. 52 is a flip-flop similar to the above, the input J pin is connected to the branch line 44, and the input A is connected to the branch line 42. A one-pulse circuit 55 similar to the one described above is made up of a two-man power N A N D gate 54, which is connected to the branch line 45 through a one-man power pin, and connected to the branch line 45 through an inverter 58 and an integral circuit 50 similar to the above to the supply input pin. 56 is a front counter consisting of a presettable counter, the clear pin (CLR) is set to 0, and the load pin (LOAD) is connected to the output f,' of the flip-flop 52.
t, connect to the clock up pin (CK/11
P) is set to 1, and the output Q pin of the flip-flop 52 and the pulse generator 16 are connected to the clock down pin (OK/DW).
The output of the two-man power NAND gate 57 is connected to the output terminal of the inverter 58. The pins A, B, O, and D of the front counter 56 are used as data keys, and the stitch number determining switch 59 is used to set the upper and lower knives 1.2 after the leading edge of the fabric begins to pass through the fabric detector 16.
This is to reset the number of stitches (LOAD) to zero (0) from the point immediately before the point (from the yarn cutting position) to the yarn cutting position. Reference numeral 60 denotes a transistor whose emitter is connected to the output Q pin of the flip-flop 52 and the pace, to which the rotary solenoid 22 is connected.

Reference numeral 61 denotes a rear counter consisting of a presettable counter similar to the above, whose load pin (t, 0AD) is connected to the output Q pin of the flip-flop 46, and the output Q of the flip-flop 46 is connected to the clock down pin (OK/DW).
The output of the two-man NAND gate 62, which connects the bottle and the output terminal of the pulse generator 16, is connected via the inverter 63. The trailing edge is the fabric detector 16
The number of stitches from the moment it passes through the upper and lower knives until it slightly passes the upper and lower knife 1.2 (from the yarn cutting position) is set using the load pin
) is preset as O. 651't
liQ-back counter 56゜61 borrow output pin (B
2 negative input OR gate (2 manual NAND
gate).

Reference numeral 66 is a monostable multi-pipe lake whose up-edge operation input pin B is connected to the output pin of the two-input OR gate 65.

67 is a transistor whose base is connected to the output Q pin of the monostable multipipe rake 66, whose collector is connected to the thread trimming solenoid 8, and whose emitter is grounded. The output Q bins of the multipipe rake 66 are connected to the C input pins of the flip-flops 46 and 52, respectively.

The present invention has the above-described configuration, and when the pedal is depressed and the overlock sewing machine rotates, the fabric advances, and at the same time, a ring is generated at the leading edge of the fabric, and this leading edge becomes the light-receiving element 9 of the fabric detector 16.
, the light from the light emitting element 13 does not reach the light receiving element 9, the output of the comparator 39 becomes O, and the input J pin of the impertub flop 46 is 01 and the pin is 2.
It becomes l through the manual NAND gate 51, and the output pin Q of the flip-flop 46 becomes 0, so that it is not input to -61. At the same time, the input J pin of the 7 flip-flop 52 is input to the 11 pin, and at the same time the inverter 41 becomes 1, the output O pulse is input from the circuit 55' to the X input pin, and the output pin Q of the flip-flop 52 is 1. When the fabric stop bar 20 of the fabric advance prevention member 17 is turned on, the rotary solenoid 22 for lifting and lowering the fabric stop bar 20 is turned ON, and the fabric stop bar 20 protrudes from the upper surface of the fabric sliding plate 11 against the elasticity of the stop bar return spring 31, and the fabric stop bar 20 protrudes from the top surface of the fabric sliding plate 11, and the fabric stop bar 20 protrudes from the top surface of the fabric sliding plate 11, and the fabric stop bar 20 protrudes from the top surface of the fabric sliding plate 11 against the elasticity of the stop bar return spring 31. This is to prevent the progress of the left-upward slope a.At the same time, the load bin (LOA) of the front counter 56 is
D) becomes 1, a pulse from the pulse generator 32 is input to the OK/DW pin via the two-man NAND gate 57 and the inverter 58, and the number of stitches preset by the stitch number determination switch 59 (i.e., the leading edge of the fabric The number of stitches is counted from when the fabric begins to pass through the fabric detector 16 until it reaches the kneading and cutting position. During the count, the fabric stopping rod 20 continues to block the progress of the inclined portion a, and when the counter 56 counts up, the leading edge of the fabric comes to the kneading yarn cutting position, and the borrow pin (BO) of the counter 56 becomes 0, so the output of the 2-input OR gate 65 becomes 1, and at the up edge where this output changes from O to 1, the monostable multivibrator 66 turns on, and its output Q.

A pulse with an appropriate pulse width determined by the volume 68 and capacitor 69 is generated from Q, and the thread trimming solenoid 8 connected to the output Q pin is turned ON, and after the upper and lower knives 1.2 are engaged, the ring base is disconnected. During this count, the fabric stopping rod 20 continues to block the progress of the inclined part a of the FitJ mark; as in the past, the upper knife 1 does not come into contact with the inclined part a when cutting the ring yarn, and the upper knife female l
cuts into the slope ifB a and ruins the product, and the pulse generated from the pin is input to the flip-flop 52 (CP).
When inputting to the bin, the output Q pin of the flip-flop 52 is inverted to O, and the load pin (LO
AD) becomes 0, the pulse from the pulse generator 32 is not input to the clock down pin (OK/DW) and counting is stopped, and the borrow output pin (BO) becomes 1 again.

At the same time, the rope cleasonoid 22 is turned OFF, and the cloth stopper rod 20 is moved back to the cloth sliding plate 1 by the elasticity of the return spring 31.
It descends to the bottom surface of 1 and is buried. As a result, the dough stopping rod 20
The fabric at the inclined portion a, which has been prevented from advancing, returns to its normal state and continues overlock sewing. Next, when the sewing is finished, the output of the parator 39 becomes l, and conversely to the above, the output Q of the flip-flop 46 is 1, and the output of the flip-flop 52 is Q.
=O, and the front counter 56 does not operate (no=1)
, the LOAD of the rear counter 61 becomes 1, and the pulse generator 32 generates 2 manual NANDs.
It is input to the clock down input pin (OK/DW) via the gate 62 and inverter 63, and is input to the needle setting switch 64.
(the trailing edge of the fabric is the fabric detector 16)
The number of stitches is counted from the moment the thread passes through until it slightly passes the cutting position.

When the counter 61 counts up, the trailing edge of the fabric comes to the kneading yarn cutting position from behind, and the borrow pin (BO) of the counter 61 becomes O, so the 2 negative input OR gate 6
The output of 5 becomes 0-41, the solenoid 8 for thread cutting is turned on, the upper knife 1 engages with the lower knife 2, and the ring group is neatly cut just before the trailing edge of the fabric. .

At this time, the flip-flop 46 has a 0. h t to input pin
+s- Stable multi-pipe rake - A pulse from the output Q pin of 66 is input, and at the up edge of this pulse, the output Q bin of flip-flop 46 is inverted to 0, and the counting operation of counter 61 is stopped (BO = 1). The time chart of this operation is shown in FIG. Note that 70 is a tip opening of a thread waste suction pipe 71 provided immediately after the upper and lower scalpels 1.2, which sucks and discards cut rings.

[Brief explanation of the drawing]

The attached drawings show an example of the implementation of the present invention, and are shown in the drawings.
The figure is a perspective view of the main parts of an overlock sewing machine equipped with the Wood 1 invention device, Fig. 2 is a side view of the main parts with a partial cross section of the material advance prevention member, and Fig. 3 shows the front edge of the material being the material advance prevention member. A plan view of the main part showing the point at which the ring group is cut from when the progress is blocked by
Figure 4 is a perspective view of the main parts of the pulse generator, Figure 5 is a block wiring diagram of the force control circuit for the thread cutting and fabric stop bar lifting solenoids, and Figure 6 shows the operation sequence of each part in Figure 5. The tie chart shown in FIG. 7 is a plan view of a main part showing a condition in which the leading edge slope of the fabric is damaged by the upper knife in a conventional overlock sewing machine. l...upper knife, 2...lower knife, 3...shaft rod, 4.
...Upper knife stand, 5...Collar, 6...Upper knife push spring, 7...Protrusion, 8...Thread trimming solenoid, 9
... Light receiving element, lO... Needle drop, 11... Cloth sliding plate, 12... Light receiving element mounting plate, 13... Light emitting element,
14...Head, 15...Light emitting element mounting plate, 16...
・Dough detector, 17...Dough blocking member, 18.19・
...Bearing, 20...Dough stopping rod, 21...Through hole,
22... Rotary solenoid, 23... Sewing machine receiving plate, 24... Mounting base, 25... Solenoid arm, 26
... Rotating shaft, 27 ... Long hole, 28 ... Pin, 29
．． 30... Stop bar restriction collar, 31... Stop salary return spring, 32... Pulse generator, 33... Main shaft, 34... Disc, 35... Magnet, 36...
...Sewing machine body shelf, 37...Element mounting stand, 38...
・Magnetic sensing element, 39... Comparator, 40...
・Volume, 41...Inverter, 42.43.
44.45... Branch line, 46... Flip-flop, 47... 3-man powered NAND gate, 48... 2-man powered NAND gate, 49... Inverter, 50...
Integral circuit, 51...2-man powered NAND gate, @hoe circuit, 56... Front counter, 57...2-man powered NAND
Gate, 58... Inverter, 59... Stitch number determining switch, 60... Transistor, 61... Rear counter, 62... 2-man power NAND gate, 63...
・Inverter, 64...Stitch number determination switch, 65・
...2 negative input OR gate, 66...monostable multivibrator, 67...transistor, 68...
Volume, 69... Condenser, 70... Opening, 71... Lint waste suction pipe, a... Fabric front edge slope,
b...Damage. Applicant: Daiwa Sewing Machine Manufacturing Co., Ltd. (2 people) Figure 1 51 1IS3 Figure M4 Figure 7

Claims (1)

[Scope of Claims] 1. Detecting when the leading edge of the fabric advances, and partially blocking the advancing of the leading edge of the fabric from the time of detection until the completion of the ring cutting operation, A method for preventing damage to fabric by a ring-cutting scalpel, characterized in that, upon completion of the ring-cutting operation, the prevention of advance of the leading edge of the fabric is released according to the detection command. A detector for detecting the arrival of fabric is installed at a position slightly in front of the ring cutting knife from a, and a fabric advancement prevention member is installed at a slight distance from the detection position so as to be movable up and down. It is characterized in that it is connected to the advance prevention member through a device that converts an electrical signal into a mechanical movement, and the time point at which the fabric advance prevention member is raised or lowered is activated by a command using the detector. A device to prevent fabric damage caused by ring-cutting scalpels.