EP0179928B1 - Fadenzufuhrvorrichtung für Nähmaschine - Google Patents

Fadenzufuhrvorrichtung für Nähmaschine Download PDF

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Publication number
EP0179928B1
EP0179928B1 EP19840111646 EP84111646A EP0179928B1 EP 0179928 B1 EP0179928 B1 EP 0179928B1 EP 19840111646 EP19840111646 EP 19840111646 EP 84111646 A EP84111646 A EP 84111646A EP 0179928 B1 EP0179928 B1 EP 0179928B1
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Prior art keywords
signal
thread
multiplying
output
value
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EP19840111646
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English (en)
French (fr)
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EP0179928A1 (de
Inventor
Kuniharu Sakuma
Sumio Goto
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Juki Corp
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Juki Corp
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Priority to EP19840111646 priority Critical patent/EP0179928B1/de
Priority to DE19843485835 priority patent/DE3485835T2/de
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    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B51/00—Applications of needle-thread guards; Thread-break detectors

Definitions

  • This invention relates to a thread feed apparatus for a sewing machine in which thread in a length corresponding to a set signal is paid out of a supply source by a paying-out device which operates based on said set signal each time a stitch is to be formed and fed to a thread take-up lever, said thread feed apparatus comprising
  • One example of known paying-out devices comprises two holding means for releasably pinching an indefinite length of thread and a thread paying-out member disposed in the thread path extending between the two holding means for operating in synchronization with a thread take-up lever whereby when the lever is not tensioning the thread, one of the holding means adjacent to a supply source of thread opens to release the thread from the nip whereas the other holding means adjacent to the lever closes to increase the length of the thread path extending between the two holding means so as to pay the thread out of the supply source, in response to the paying-out of the thread by a preset amount, the holding means adjacent to the supply source closes to prevent the thread from being further paid out and the holding means adjacent to the lever opens and the paid out thread is drawn out of the zone between the two holding means as the lever rises again.
  • a disc having a length of thread wound about the periphery of the disc is provided or a pair of rollers are provided in opposing and spaced relationship to releasably pinch the thread therebetween and at least one of the rollers is intermittently rotated by a stepping motor each time one stitch is formed.
  • a pair of spaced thread guides are provided in the thread path, a reciprocal paying-out member is provided to traverse the thread path and the movement amount of the reciprocal paying-out member is related to the movement amount of drive means such as a pulse motor or linear motor.
  • the prior art thread paying-out devices referred to above have the disadvantage that since the balance in tension between upper and lower threads can not be varied as desired, the thread paying-out devices are not applicable to some sewing operations in which a single workpiece is sewn with gathers and two workpieces having different lengths are sewn together with the longer workpiece gathered.
  • the workpiece feed amount has been mechanically adjusted to square the feed amount in the forward direction with that in the reverse direction.
  • differences between absolute feed amounts in the forward and reverse directions due to variation in tolerances of parts or disaccordance between an actual workpiece feed amount and a predetermined workpiece feed amount corresponding to the position of a feed adjusting device or a workpiece feed amount indicated by an adjusting dial or the like interlocked with the feed adjusting device could not be adjusted.
  • one object of the present invention is to eliminate the disadvantages inherent in the prior art thread mechanisms by varying the coefficient of a workpiece thickness value.
  • a further object of the present invention is to maintain the balanced condition between upper and lower threads constant independent of variation in workpiece thickness.
  • a conventional sewing machine 1 wherein the thread feed mechanism of the invention is incorporated is schematically shown and the sewing machine generally comprises a main shaft (not shown) operatively connected to a drive source (not shown) to be rotated by the drive source, a needle bar 3 having a needle 2 carrying a length of thread T secured to the lower end of the bar and interlocked with the main shaft for vertical movement as the main shaft rotates and a thread take-up lever 5 supporting the section of the thread T between a bobbin 4 and the needle 2 and movable between two positions as the main shaft rotates so as to strain and slacken the thread T.
  • the relationship of the needle bar 3 and thread take-up lever 5 with respect to rotative angles of the main shaft is shown in Fig. 5.
  • First and second holding means 6 and 7 are provided in spaced upstream and downstream relationship in the thread path extending between the bobbin 4 and thread take-up lever 5.
  • the first holding means consists of a first electromagnet or solenoid 8 and a pair of holding discs 10 adapted to releasably pinch the thread T therebetween so that when the electromagnet or solenoid 8 is excited the discs attract each other to releasably pinch the thread therebetween and when the electromagnet or solenoid 8 is demagnetized the discs separate from each other to release the thread from their nip.
  • the second holding means 7 consists of a second electromagnet or solenoid 9 and a pair of holding discs 11. The functions of the electromagnet or solenoid 9 and holding discs 11 are the same as those of the corresponding components of the first holding means 6.
  • a paying-out member 12 is rockably supported at one end to an eccentric cam 13 interlocked with the main shaft for rocking about a stub shaft 14 by a predetermined angle as the eccentric cam 13 rotates in response to the rotation of the main shaft.
  • the free end of the paying-out member 12 intersects the thread path extending between the upstream and downstream holding means 6 and 7 so that when the point of the needle 2 is positioned below the upper surface of the bed of the sewing machine as shown in Fig. 5, the paying-out member 12 first engages the thread T to increase the length of the thread path between the holding means 6 and 7 and then minimizes the thread path length by the time when the lever 5 will tension the thread.
  • a rotatable member 15 is provided in the thread path extending between the holding means 6 and 7 and adapted to rotate by an angle in proportion to the movement distance of the thread T as the thread T moves along the thread path.
  • Fig. 2 is a block diagram of the electrical circuit for use in the thread feed mechanism in a sewing machine according to the present invention. The operation sequence will be described referring to the electrical circuit, a paying-out detection device 16 produces one pulse each time the rotatable member 15 rotates by a predetermined angle.
  • a first position detection device 17 is so disposed with respect to the main shaft or a member interlocked with the shaft that the device 17 detects a particular angle of rotation of the main shaft which corresponds to the time at which the lower end of the needle 2 is positioned above the upper surface of the sewing machine bed and outputs a higher level signal (which will be referred to as “signal H” herein) and the device 17 also detects another particular angle of rotation of the main shaft which corresponds to the time at which the lower end of the needle 2 is positioned below the upper surface of the sewing machine bed and outputs a lower level signal (which will be referred to as "signal L" herein).
  • a second position detecting device 18 is so disposed with respect to the main shaft or a member interlocked with the main shaft that the device 18 detects a particular angle of rotation of the main shaft which corresponds to the time at which the thread take-up lever 5 strains the thread T and outputs one signal H.
  • a counter 19 is set by the rise of a signal from a timer MS1 which is actuated by the rise of a signal from the first position detection device 17 and counts pulses from the paying-out detection device 16.
  • a third position detection device 30 detects a particular angle of rotation of the main shaft which corresponds to the time period from the time just before the needle 2 invades into the sewing machine bed to the time just before the needle 2 rises out of the sewing machine bed and produces a signal H.
  • a flip-flop FF1 is reset by turning the start switch (not shown) for the sewing machine off and the reset of the flip-flop is released by turning the start switch on whereby an output at the terminal Q of the flip-flop FF1 is inverted from L to H in response to the rise of an output from the third position detection device 30.
  • a multiplexer 20 outputs an input signal from a first setting device 21 while the multiplexer is receiving a signal L from FF1 and outputs an input signal from a holding circuit 22 while the multiplexer is receiving a signal H from FF1.
  • the holding circuit 22 operates in response to the rise of an output from a timer MS2 to receive an input signal from a substracter 23 and at the same time to output.
  • the substracter 23 substracts the value c of an output signal of a second holding circuit 25 of which description will be made hereinafter from the value e of a second setting device 24 to provide obtain a signal having the value f which is the output from the substracter.
  • the first and second setting devices 21 and 24 are adapted to set the length of the thread T to be payed out in proportion to the length of the thread T required for forming one seam.
  • the first setting device 21 produces a digital code corresponding to an average ideal thread paying-out length for each selected stitch pattern whilst the second setting means produces a digital signal corresponding to the thread length set for one stitch formation as will be described hereinafter in connection with Fig. 4.
  • the digital code is related to the number of pulses from the paying-out detection device 16 corresponding to an angle of rotation of the rotatable member 15 in proportion to the thread paying-out amount.
  • a second substracter 26 substracts the value b of an output signal of the multiplexer 20 from the value a of an output signal of the counter 19 to provide an output having the value of c .
  • the second holding circuit 25 operates in response to the rise of a signal from the third position detection device 30 to receive an output having the value c from the second substracter 26 and simultaneously to output.
  • a comparison circuit 27 compares the values of outputs of the counter 19 and multiplexer 20 with each other and when the values of these outputs coincide with each other, the comparison circuit 27 produces a coincidence signal H.
  • a flip-flop FF2 is reset by the rise of a signal from the timer MS1 and outputs a signal L at the Q terminal of FF2 at the particular time. The output at the Q terminal of FF2 is inverted from L to H with a coincidence signal from the comparison circuit 27.
  • Operation circuits 28 and 29 receive signals H from FF2 and open to excite their associated solenoids 8 and 9, respectively and close upon receipt of signals L from FF2 to demagnetize the first and second solenoids, respectively.
  • the operation circuit 28 With the operation circuit 28 in its open condition, when the operation circuit receives a power down signal having the level L from the second position detection device 18 (when the second position detection device 18 produces a signal L), the first solenoid 8 is supplied thereto current in an amount smaller than that of current to be supplied thereto when the operation circuit 28 receives a signal L. That is, one example of the operation circuit 28 is represented by an analog circuit in Fig. 3.
  • P denotes a known OP amplifier having comparison function and Tr1, Tr2 and Tr3 denote transistors.
  • FF3 When the sewing machine is in its nonoperative condition, FF3 receives a signal H at its terminal R and outputs a signal L at its terminal Q. When the sewing machine starts to operate, FF3 receives a signal L at its terminal R to release its reset. Upon receipt of a signal H from an AND gate G, FF3 outputs a signal H at the terminal Q.
  • Reference numeral 47 denotes an alarm such as a buzzer or lamp and provides sound, light or other indication through a timer TM for a predetermined period when FF3 outputs a signal H at the terminal Q.
  • an amplitude signal Y relating to the amplitude of the needle bar 3 and a feed amount signal X relating to the feed pitch of a workpiece are signals read out of memories such as ROM and RAM (not shown) or obtained by detecting the positions of known needle amplitude and feed adjusting devices (not shown) operable based on these signals.
  • the detection times of these signals are detected in relation to the fall and rise of an output of the third position detection device 30 as shown in Fig. 5 and the feed amount signal X is maintained by a holding circuit (not shown) until the amplitude signal Y is detected.
  • These signals X and Y are processed by square multipliers 31 and 32, respectively and added together by an adder 33.
  • An output from the adder 33 is multiplied by an output m of a feed amount (seam pitch) coefficient setting switch 35 in a multiplier 34 and an output of the multiplier 34 is processed by a k'1 multiplier 36 and a square root arithmetic unit 37.
  • An output from the square root arithmetic unit 37 is passed through a k'2 multiplier 38 to an adder 39 and an output from the k'1 multiplier 36 is directly passed to an adder 39.
  • the added data is passed to an adder 40.
  • the feed amount coefficient setting switch 35 has a code of several bits and can output a digital code corresponding to manual operation mode.
  • a workpiece thickness signal D corresponding to the position of the presser foot (not shown) above the upper surface of the sewing machine bed is detected in the same timing relationship as the detection of a feed amount signal X and multiplier by an output k3 of a coefficient counter 42 in a multiplier 41.
  • An output of the multiplier 41 is added to an output data from the adder 39 in an adder 40 an output of which is in turn processed through a k4 adder 43.
  • a paying-out amount arithmetic unit 44 converts the output of the k4 adder into the number of generated pulses the paying-out detector 16 corresponding to an angle of rotation of the rotatable member 15 in proportion to a predetermined paying-out amount of the thread T whereby a digital code corresponding to the predetermined paying-out amount of the thread T is produced.
  • the coefficient counter 42 can vary the output value k3 stepwise within a predetermined range with the initial value "1" as the center in relation to the operation of up-down switches 45 and 46 and is reset upon receipt of a signal H at the terminal R of the counter whereby an output of the counter becomes the initial value "1" and the number of pulses corresponding to the output value k3 of the counter 42 is indicated on the indication window (not shown) provided in the front of the sewing machine framework.
  • a pattern change-over signal E and a power source input signal F are signals H which are related to the stitch pattern selection operation and the closing of the power source, respectively and are generated at predetermined times.
  • the mechanism operates as follows: In operation, first of all, the stitch pattern selection means selects a stitch pattern whereupon the first setting device 21 outputs a signal d corresponding to the inherent thread paying-out length which in turn corresponds to the selected stitch pattern. Thereafter, the sewing machine starts to operation to release the reset of FF1, but an output at the terminal Q of FF1 remains L and an output d of the first setting device 21 is passed through the multiplexer 20 to the comparison circuit 27 and substracter 26.
  • the start of the sewing machine also causes the thread take-up lever 5 which is now at the top dead center to descend until the section of the thread T extending between the thread take-up lever 5 and needle 2 slackens whereupon the counter 19 resets itself in response to the rise of a signal from the timer MS1 and at the same time, since FF2 clears, the operation circuit 28 closes to demagnetize the first electromagnet or, solenoid 8 which in turn release the thread T from the nip in the holding means 6. Simultaneously, the operation circuit 29 opens to excite the second electromagnet or solenoid 9 to cause the holding means 7 to pinch the thread T so as to arrest the movement of the thread T therethrough.
  • the paying-out member 12 rotates from the position as shown in Fig. 1 about the stub shaft 14 in the counterclockwise direction to flex the thread T between the two holding means 6 and 7 so as to gradually increase the length of the thread path and as a result, the thread T is payed out of the bobbin 4 in an amount corresponding to the increasement in the length of the thread path.
  • the rotatable member 15 When the thread T is payed out of the bobbin 4 by carrying out the operation procedure described above, the rotatable member 15 is rotated in the clockwise direction as seen in Fig. 1 by the thread being payed out and the paying-out detection device 16 produces a number of pulses proportion to an angle of rotation of the rotary member 15. The pulses are counted by the counter 19 and the count is input to the comparison circuit 27 and substracter 26.
  • the comparison circuit 27 produces a coincidence signal of H which sets FF2 whereby an output at the terminal Q thereof is inverted from L to H so that the first solenoid 8 is excited to cause the holding means 6 to pinch the thread T so as to prevent the thread T from further being payed out of the bobbin 4 and simultaneously demagnetize the second solenoid 9 so as to release the holding means 7 which in turn allows the thread T to pass therethrough.
  • the comparison circuit 27 produces a coincidence signal and since the holding means 6 pinches the thread T to prevent the thread to pass therethrough whereas the holding means 7 releases its nip to allow the thread T to pass therethrough so that the thread take-up lever 5 allows the section of the thread T extending between the lever 5 and needle 2, even if the paying-out member 12 further rotates in the counterclockwise direction, slackened thread section passes through the holding means 7 and the thread section being payed out by the rotating paying-out member 12 is retained between the holding means 6 and 7 and thus, the thread T is not positively tensioned. If the thread is positively tensioned, the tensioned thread pulls the rest of the thread out of the bobbin 4.
  • FF1 is set by the rise of a signal from the third position detection device 30 and an output at the terminal Q of FF1 is inverted from L to H
  • a signal from the second setting device 24 is input through the multiplexer 20 to the comparison circuit 27 in a predetermined time after FF1 was set or in response to the rise of an output from the timer MS2.
  • the thread amount to be payed out for forming the first seam is determined by a signal from the first setting device 21
  • the thread paying-out amount for each of the second and succeeding stitches is determined by a signal from the second setting device 24 which is obtained for such stitch by computing a feed pitch, a needle amplitude and a workpiece thickness.
  • the comparison circuit 27 produces a coincidence signal.
  • the substracter 23 substracts the output value c of the substracter 26 from the output value e of the second setting device 24 to provide an output having the value f which is passed to one input of the comparison circuit 27 through the multiplexer 20.
  • the comparison circuit 27 produces a coincidence signal. The procedure is repeated.
  • the transistor Tr3 turns on and the reference voltage of the OP amplifier P is substantially lower than that in a case as will be described hereinafter so that excitation current for the first solenoid 8 becomes smaller.
  • the holding means 6 is imparted thereto a nip force which is not so great as to feed the thread to the thread path between the holding means 6 and 7 by the operation of the paying-out member 12.
  • the adjustment by the feed amount coefficient setting switch 35 is performed when a feed pitch to be input the computing system does not coincide with an actual feed pitch in a sewing machine of the type in which an input signal to a feed or needle amplitude stepping motor is input to the motor in a thread paying-out computing mode.
  • the value of the coefficient k3 for a workpiece thickness signal D among outputs of the k4 adder 43 becomes greater stepwise within a preset range with the initial value l as the center and when the down-switch 46 is manipulated, the value of the coefficient k3 becomes smaller stepwise whereby an output of the second setting device 24 varies, but the coefficient counter 42 resets in response to pattern selection and power source closing and the value of k3 returns to the initial value l.
  • the adjustment is made as desired when the balance in tension between upper and lower threads is intentionally varied in order to sew a single workpiece with gathers or two workpieces having different lengths with the longer workpiece gathered or pull the lower or upper thread in sewing.
  • the thread feed mechanism in a sewing machine comprises a first signal generation device for producing a thread feed amount signal X corresponding to a workpiece feed pitch for each stitch and an amplitude signal Y corresponding to the amplitude of a needle bar in response to the operation of the sewing machine before a thread take-up lever completes the tensioning of an indefinite length of thread, a second signal generation device for detecting the thickness of a workpiece at the sewing area in the sewing machine before the lever completes the tensioning of the thread and producing a workpiece thickness signal D corresponding to the thickness of said workpiece, first means 31, 32 and 33 for adding square values of the feed amount and needle amplitude signals together and outputting the added value, second means 37 and 38 for miltiplying a square root of the output of the first means by a coefficient k'2 and outputting the multiplied value, third manual means 45, 46 and 42 for outputting signals of different values corresponding to operation modes of the third means, fourth means 41 for multiplying
  • the thread feed mechanism in a sewing machine comprises a first signal generation device for producing a feed amount signal X corresponding to a workpiece feed pitch for each seam and an amplitude signal Y corresponding to the amplitude of a needle bar in response to the operation of the sewing machine before a thread take-up lever completes the tensioning of an indefinite length of thread, a second signal generation device for detecting the thickness of a workpiece at the sewing area in the sewing machine before the lever completes the tensioning of the thread and producing a workpiece thickness signal D corresponding to the thickness of the workpiece, first means 31, 32 and 33 for adding square values of the feed amount and amplitude signals and outputting the resulting value, manual stitch pitch coefficient setting means 35 for producing a signal m which varies depending upon the operation mode of said coefficient setting means, second means 37 and 38 for multiplying the output of the first means by the output of the coefficient means and outputting the resulting value, third means 45, 46 and 42 for multiplying a square root of the output of said second means
  • the paying-out member 12 in the form of a bar is adapted to reciprocally move as the cam member 13 rotates
  • the paying-out member may be formed in the periphery thereof with a cam face in opposition to the thread path as shown in Japanese Patent Application No. 82712/1982 without departing the scope of the invention.
  • the holding means may be replaced by a disc having a length of thread wound about the outer periphery or a pair of opposing rollers having a length of thread nipped therebetween with one of the rollers being rotated by a stepping motor based on a set signal.
  • first and second setting devices 21 and 24 are provided and the first setting device 21 produces a digital code corresponding to an average ideal thread paying-out length which varies depending upon a selected stitch pattern, it may be also possible to produce the same digital code for all stitch patterns.

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  • Sewing Machines And Sewing (AREA)

Claims (5)

  1. Fadenzuführungsgerät für eine Nähmaschine, bei der aus einer Versorgungsquelle (4) Faden in einer Länge entsprechend einem Einstellsignal durch eine Ausgabeeinrichtung ausgegeben wird, die auf der Basis des Einstellsignals jedesmal dann in Funktion tritt, wenn ein Stich ausgeführt und einem Fadenanzugshebel (5) zugeführt werden muß, wobei das Fadenzuführungsgerät aufweist:
    (a) eine erste Signalerzeugungseinrichtung zum Erzeugen eines Vorschubbetragssignals (X), entsprechend der Fertigungsstückteilung für einen einzelnen Stich, und eines Amplitudensignals (Y), entsprechend der Amplitude einer Nadelstange als Antwort auf den Betrieb der Nähmaschine, ehe der genannte Hebel das Spannen des Fadens bei diesem Stich beendet;
    (b) eine zweite Signalerzeugungseinrichtung zum Erfassen der Dicke des Fertigungsstückes im Nähbereich der Nähmaschine, und zum Erzeugen eines Fertigungsstückdickensignals (D) entsprechend der genannten Dicke, ehe der Fadenanzugshebel das Spannen des Fadens beim genannten Stich beendet; und
    (c) Quadrier- und Addiereinrichtungen (31, 32, 33) zum Erzeugen von Quadratwerten des Vorschubbetragssignals (X) und des Amplitudensignals (Y), und zum Addieren der Quadratwerte und Ausgeben des Ergebniswertes (X² + Y²);

    gekennzeichnet durch:
    (d) Wurzelbildungs- und Multiplikationseinrichtungen (37, 38) zum Ziehen der Quadratwurzel der Ausgabe der Quadrier- und Addiereinrichtungen (31, 32, 33) sowie zum Multiplizieren der Quadratwurzel mit einem Koeffizienten (k'₂), und Ausgeben des Ergebniswertes (k'₂ √ X² ¯ + ¯ Y²) ¯
    Figure imgb0032
     ;
    (e) Signalerzeugungseinrichtungen (45, 46, 42) zum Erzeugen eines Signals (k₃), das sich in Abhängigkeit vom Betriebsmodus der Signalerzeugungseinrichtungen ändert;
    (f) Multipliziereinrichtungen (41) zum Multiplizieren des Fertigungsstückdickensignals (D) mit der Ausgabe der Signalerzeugungseinrichtungen (45, 46, 42), und Ausgeben des Ergebniswertes (k₃D); und
    (g) Addiereinrichtungen (40) zum Addieren der Ausgaben der Wurzelbildungs- und Multipliziereinrichtungen (37, 38) und der Multipliziermittel (41), und Ausgeben des Ergebniswertes;
    wodurch die Ausgabe der Addiereinrichtungen (40) zum Einstellsignal oder zum Bezugsdatum für das Einstellsignal wird.
  2. Fadenzuführungsgerät nach Anspruch 1, gekennzeichnet durch:
    (h) weitere Addiereinrichtungen (39) zum Addieren der Ausgaben der Quadrier- und Addiereinrichtungen (31, 32, 33) und der Wurzelbildungs- und Multipliziereinrichtungen (37, 38), und zum Übertragen des Ergebniswertes |(X² + Y²) + k'₂ √ X² + Y² ¯ |
    Figure imgb0033
     an die Addiereinrichtungen (40), um von diesen einen Ergebniswert |(X² + Y²) + k'₂ √ X² + Y² ¯ + k₃D |
    Figure imgb0034
    Figure imgb0035
    zu erhalten.
  3. Fadenzuführungsgerät nach Anspruch 1, gekennzeichnet durch:
    (i) Einstell-Vorrichtung (35) zum manuellen Einstellen des Vorschubschrittkoeffizienten, um ein Signal (m) zu erzeugen, dessen Wert sich in Abhängigkeit vom Betriebsmodus der Koeffizienteneinstellvorrichtungen ändert; und
    (j) weitere Multipliziermittel (34) zum Multiplizieren der Ausgabe der Koeffizienten-Einstellvorrichtung (35) mit der Ausgabe der Quadrier- und Addiereinrichtungen (31, 32, 33), und zum Übertragen des Ergebniswertes |m(X² + Y²)|
    Figure imgb0036
     an die Wurzelbildungs- und Multipliziereinrichtungen (37, 38), um an die weiteren Addiereinrichtungen (40) einen Wert |k'₂ √ X² + Y²) ¯ |
    Figure imgb0037
     auszugeben und zu übertragen.
  4. Fadenzuführungsgerät nach Anspruch 1 und 2, gekennzeichnet durch:
    (i) Einstell-Vorrichtung (35) zum manuellen Einstellen des Vorschubschrittkoeffizienten, um ein Signal (m) zu erzueugen, dessen Wert sich in Abhängigkeit vom Betriebsmodus der Koeffizienteneinstellvorrichtungen ändert; und
    (k) weitere Multipliziermittel (34) zum Multiplizieren der Ausgabe der Koeffizienten-Einstellvorrichtung (35) mit der Ausgabe der Quadrier- und Addiereinrichtungen (31, 32, 33), und zum Übertragen des Ergebniswertes |m(X² + Y²)|
    Figure imgb0038
     sowohl an weitere Multipliziereinrichtungen (36) zum Multiplizieren des Ergebniswertes mit einem Koeffizienten k'₁ als auch an die Wurzelbildungs- und Multipliziereinrichtungen (37, 38), wobei die Ergebniswerte der weiteren Multipliziereinrichtungen (36) und der Wurzelbildungs- und Multipliziereinrichtungen (37, 38) an die Addiereinrichtungen (39) übermittelt werden, um einen Additionswert |k'₁.m (X² - Y²) + k'₂ √ (X² + Y²) ¯ |
    Figure imgb0039
    Figure imgb0040
    an die Addiereinrichtungen (40) auszugeben und zu übertragen.
  5. Fadenzuführungsgerät für eine Nähmaschine, bei der aus einer versorgungsquelle (4) Faden in einer Länge entsprechend einem Einstellsignal durch eine Ausgabeeinrichtung ausgegeben wird, die auf der Basis des Einstellsignals jedesmal dann in Funktion tritt, wenn ein Stich ausgeführt und einem Fadenanzugshebel (5) zugeführt werden muß, wobei das Fadenzuführungsgerät aufweist:
    (a) eine erste Signalerzeugungseinrichtung zum Erzeugen eines Vorschubbetragssignals (X) entsprechend dem Fertigungsstückteilung für einen einzelnen Stich, und eines Amplitudensignals (Y) entsprechend der Amplitude einer Nadelstange als Antwort auf den Betrieb der Nähmaschine, ehe der genannte Hebel das Spannen des Fadens bei diesem Stich beendet;
    (b) eine zweite Signalerzeugungseinrichtung zum Erfassen der Dicke des Fertigungsstückes im Nähbereich der Nähmaschine, und zum Erzeugen eines Fertigungsstückdickensignals (D) entsprechend der genannten Dicke, ehe der Fadenanzugshebel das Spannen des Fadens beim genannten Stich beendet; und
    (c) Quadrier- und Addiereinrichtungen (31, 32, 33) zum Erzeugen von Quadratwerten des Vorschubbetragssignals (X) und des Amplitudensignals (Y), und zum Addieren der Quadratwerte und Ausgeben des Ergebniswertes (X² + Y²);
    gekennzeichnet durch:
    (d) Wurzelbildungs- und Multiplikationseinrichtungen (37, 38) zum Ziehen der Quadratwurzel der Ausgabe der Quadrier- und Addiereinrichtungen (31, 32, 33), sowie zum Multiplizieren der Quadratwurzel mit einem Koeffizienten (k'₂) und Ausgeben des Ergebniswertes (k'₂ √ X² + Y²); ¯
    Figure imgb0041
    (e) handbetätigte Vorrichtungen (35) zum Erzeugen eines Signals (m), dessen Wert sich in Abhängigkeit vom Betriebsmodus der Koeffizienteneinstellvorrichtungen ändert;
    (f) Multipliziermittel (34) zum Multiplizieren der Ausgabe der Koeffizienteneinstellvorrichtungen (35) mit der Ausgabe der Quadrier- und Addiereinrichtungen (31, 32, 33), und zum Liefern des Ergebniswertes |m(X² + Y²)|
    Figure imgb0042
     an die Wurzelbildungs- und Multipliziereinrichtungen (37, 38); und
    (g) Addiereinrichtungen (40) zum Addieren der Ausgaben der Wurzelbildungs- und Multipliziereinrichtungen (37, 38) sowie der zweiten Signalerzeugungseinrichtungen, und Ausgeben eines entsprechenden Ergebniswertes,
    (h) wodurch die Ausgabe der Addiereinrichtungen (40) zum Einstellsignal oder zum Bezugsdatum für das Einstellsignal wird.
EP19840111646 1984-09-28 1984-09-28 Fadenzufuhrvorrichtung für Nähmaschine Expired - Lifetime EP0179928B1 (de)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP19840111646 EP0179928B1 (de) 1984-09-28 1984-09-28 Fadenzufuhrvorrichtung für Nähmaschine
DE19843485835 DE3485835T2 (de) 1984-09-28 1984-09-28 Fadenzufuhrvorrichtung fuer naehmaschine.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19840111646 EP0179928B1 (de) 1984-09-28 1984-09-28 Fadenzufuhrvorrichtung für Nähmaschine

Publications (2)

Publication Number Publication Date
EP0179928A1 EP0179928A1 (de) 1986-05-07
EP0179928B1 true EP0179928B1 (de) 1992-07-22

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ID=8192185

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EP19840111646 Expired - Lifetime EP0179928B1 (de) 1984-09-28 1984-09-28 Fadenzufuhrvorrichtung für Nähmaschine

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DE (1) DE3485835T2 (de)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4928611A (en) * 1988-11-15 1990-05-29 Brother Kogyo Kabushiki Kaisha Sewing machine with guide and ironing means for folding back and pressing stitched fabric margins
JP2008245731A (ja) * 2007-03-29 2008-10-16 Juki Corp ミシン

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2809848C2 (de) * 1977-03-07 1983-01-05 Janome Sewing Machine Co., Ltd., Tokyo Elektronisch gesteuerte Musternähmaschine mit Fadenspannvorrichtung
US4166423A (en) * 1978-02-28 1979-09-04 The Singer Company Adaptive sewing machine
JPS54163147A (en) * 1978-06-13 1979-12-25 Janome Sewing Machine Co Ltd Device for automatically adjusting upper thread on sewing machine
US4215641A (en) * 1979-07-05 1980-08-05 The Singer Company Electronic control of needle thread in a sewing machine
JPS56106690A (en) * 1980-01-29 1981-08-25 Brother Ind Ltd Automatic cotton toning device for sewing machine

Also Published As

Publication number Publication date
DE3485835T2 (de) 1993-03-04
DE3485835D1 (de) 1992-08-27
EP0179928A1 (de) 1986-05-07

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