EP0173897B1 - Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine - Google Patents

Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine Download PDF

Info

Publication number
EP0173897B1
EP0173897B1 EP85110198A EP85110198A EP0173897B1 EP 0173897 B1 EP0173897 B1 EP 0173897B1 EP 85110198 A EP85110198 A EP 85110198A EP 85110198 A EP85110198 A EP 85110198A EP 0173897 B1 EP0173897 B1 EP 0173897B1
Authority
EP
European Patent Office
Prior art keywords
underthread
feeler bar
deflection
feeler
lower thread
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85110198A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0173897A1 (de
Inventor
Heinz-Georg Slomma
Alfred Desprez
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ZSK Stickmaschinen GmbH
Original Assignee
ZSK Stickmaschinen GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19848426133 external-priority patent/DE8426133U1/de
Priority claimed from DE19858518089 external-priority patent/DE8518089U1/de
Application filed by ZSK Stickmaschinen GmbH filed Critical ZSK Stickmaschinen GmbH
Publication of EP0173897A1 publication Critical patent/EP0173897A1/de
Application granted granted Critical
Publication of EP0173897B1 publication Critical patent/EP0173897B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B51/00—Applications of needle-thread guards; Thread-break detectors
    • D—TEXTILES; PAPER
    • D05—SEWING; EMBROIDERING; TUFTING
    • D05B—SEWING
    • D05B63/00—Devices associated with the loop-taker thread, e.g. for tensioning

Definitions

  • the invention relates to a device for monitoring the lower thread of an embroidery, quilting or sewing machine with a rotating round hook and a thread monitor arranged between the round hook and needle plate, which detects the position of the lower thread deflected in the axial direction by the rotating hook within a predetermined angle of rotation range by a arranged in the deflection area of the lower thread, designed as part of a switch and monitored against a restoring force movable probe bracket.
  • DE-U-1 862 643 shows a bobbin thread monitor, in which a sensor bracket surrounding the bobbin thread with one end is attached to a shaft, which is controlled by a cam, so that the sensor bracket comes into an active position in a predetermined range of rotation angles . In this active position, the sensor bracket keeps an assigned microswitch closed against the force of a leaf spring when the lower thread is present. In the event of a thread break, the retaining force exerted by the lower thread on the sensor bracket is missing, so that the leaf spring pivots the sensor bracket and opens the microswitch.
  • This known bobbin thread monitor has the disadvantage, on the one hand, of a complicated structure and, on the other hand, of a certain inertia, so that the speed of the machines equipped with such bobbin thread monitors is limited.
  • the forces exerted on the lower thread by the feeler are also so high that they result in a large mechanical load on the lower thread.
  • DE-A-3 029 782 it is known from DE-A-3 029 782 to arrange a piezoelectric element between the throat plate and the round looper, which is set in motion by the deflected lower thread, which are monitored and signal their changes or absence that the bobbin thread is broken.
  • the invention has for its object to develop a device for monitoring the lower thread of the type described in such a way that a high level of functional reliability is achieved with little technical effort, which also enables the monitoring of the lower thread of high-speed embroidery, quilting or sewing machines.
  • the probe bracket is arranged on the underside of the throat plate and with a crank-like middle part arranged between two bearings for contact with the lower thread, with an angled articulation part for articulating a tension spring and with an angled end piece for contact with an angled part a contact pin is formed, and that the probe bracket is movable by the deflection movement of the lower thread against the action of a restoring force.
  • a short switching impulse is sufficient for each machine cycle to monitor the bobbin thread for a thread break.
  • This switching pulse is emitted by the movement of the probe bracket within the rotation angle range for which the electro-mechanical contact switch is switched on by a suitable switch, for example a proximity switch.
  • a suitable switch for example a proximity switch.
  • the probe bracket designed according to the invention avoids high mechanical loads on the lower thread and does not require any limitation of the working speed of the machine.
  • the bobbin thread monitor according to the invention is not susceptible to interference. It is also easily adjustable. By angling both the end piece of the feeler and the cooperating end of the contact pin, the deflection movement of the lower thread is increased by the round hook for the contact process, so that clear signals can be generated even with small deflections of the lower thread.
  • the force required to twist the stylus by the lower thread can be determined by choosing a suitable tension spring.
  • the probe bracket is arranged on the underside of the throat plate and is designed as a leg spring with a leg firmly clamped in a bearing block, a spring part directly adjoining the clamping point and comprising at least one turn, and with a movable leg is, the end piece with a Contact pin cooperates, and that the probe bracket can be moved by the deflection movement of the lower thread against the action of a restoring force.
  • the spring generating the contact pressure is formed by the actual probe bracket itself, and separate bearings can be dispensed with because the contact part of the probe bracket obtains its mobility through the integrated spring part.
  • the movable leg of the feeler arm can be formed with at least one bend in the area of the lower thread, on which the lower thread is guided to avoid an evasive movement transverse to the axial deflection movement. This configuration ensures that the deflection movement of the lower thread running in the axial direction of the round hook is fully used to monitor the presence and that lateral evasive movements of the lower thread cannot lead to false signals.
  • the invention further proposes to guide the free end of the probe bracket leg in a guide groove of the bearing block carrying the contact pin.
  • This guide groove also avoids malfunctions, and according to a further feature of the invention, the force required to deflect the probe bracket can be reduced if the guide groove is inclined in accordance with the main direction of deflection of the lower thread, i.e. running at an acute angle to the level of the throat plate, is formed in the bearing block. In this case, the direction of force and the direction of deflection are approximately the same, so that approximately optimal conditions are achieved.
  • a proximity initiator can be provided in the region of the free end of the stylus, whereby, according to a preferred embodiment of the invention, the stylus consists of ferromagnetic material and a magnet generating the restoring force is provided .
  • the restoring force for the stylus is no longer determined by its spring properties, but by an independent magnet, which according to the preferred embodiment can be a permanent magnet. Accordingly, the design and dimensions of the probe bracket can be freely selected within wide limits and can thus be adapted to the respective working speeds. In addition, the probe bracket can also be freely rotatably mounted below the throat plate.
  • the magnet should preferably be arranged in the vicinity of the mounted end of the probe bracket under the throat plate, because there the deflection of the probe bracket is comparatively small and the probe bracket is consequently always subjected to an essentially constant magnetic force.
  • the deflection of the stylus can be limited by stops, which are preferably arranged in the area of the free end of the stylus, because there the deflection of the stylus is relatively large and because the stops can then also be set up so that the proximity initiator in the deflection plane of the stylus , but is arranged outside the range of movement of the free end. Touching the proximity initiator by the free end of the stylus is avoided.
  • proximity sensor in the sense of the invention is understood to mean any contactless switching element, e.g. B. capacitors, inductors, Hall sensors or light barriers.
  • a round looper 1 can be seen, which is fastened on a looper shaft 2, which rotates twice, for example, per machine revolution, with the bobbin thread every second looper revolution is scanned.
  • This scanning is carried out by means of a device which is arranged below the stitch plate 3, which is partially shown in section in the drawings and which has a stitch hole 3a for the needle 4.
  • the lower thread 5 can be seen, which is drawn off from the bobbin case 6 of the round hook 1, which can be seen in FIGS. 1 and 4.
  • the round gripper 1 is provided on its cylindrical outer circumference with a gripper plate 1 a, the development of which is shown in FIG. 11. With the help of this hook plate 1a a, the lower thread 5 is deflected in the axial direction of the hook shaft 2 per revolution of the round hook 1. This deflection of the lower thread 5 is scanned to determine whether a lower thread 5 is properly present, which comes out of the bobbin case 6 through the
  • the stitch hole 3a leads through to the embroidery material 7 and is knotted on the underside thereof with the upper thread, not shown.
  • the monitoring device comprises a probe bracket 8 which is rotatably mounted in two bearings 9 on the underside of the needle plate 3. Between the two bearings 9, the stylus 8 forms a crank-like central part 8a, as can be seen in particular in FIG. 1. Outside the one bearing 9, the feeler 8 is provided with an angled articulation part 8b, on which a tension spring 10 engages, the other end of which engages a bearing pin 11 (see FIGS. 2 and 3). Outside the other bearing 9, the stylus 8 has a likewise angled end piece 8c, which is designed as a contact-making part of the stylus 8 and in the exemplary embodiment according to FIGS. 1 to 3 interacts with a bend 12a of a contact pin 12.
  • This contact pin 12, like the probe bracket 8, is connected to an associated circuit via a cable 13.
  • the contact pin 12 is fastened to the underside of the throat plate 3 with the aid of a bearing piece 14.
  • the looper sheet 1a of the round looper 1 deflects the lower thread 5 in the axial direction of the looper shaft 2, as can be seen from a comparison of FIGS. 2 and 3 and better still from FIG. 11 of the drawings.
  • This deflection movement of the lower thread 5 resting on the crank-like central part 8a of the feeler 8 causes the entire feeler 8 to rotate in its bearings 9.
  • This rotation of the feeler 8 takes place clockwise in FIGS. 2 and 3, so that the angled end piece 8c of the feeler 8 according to Fig. 3 is briefly lifted from the bend 12a of the contact pin 12.
  • the electro-mechanical contact switch formed by the stylus 8 and the contact pin 12 is thus opened briefly due to the deflection of the lower thread 5.
  • the feeler 8 is formed by a type of leg spring, one leg 8d of which is firmly clamped in a bearing block 15.
  • a spring part 8e which comprises at least one turn, which, in the exemplary embodiment according to FIG. 4, comprises four turns and merges into a movable leg 8f which projects into a guide groove 16a of a bearing block 16, which continues from the fixed contact pin 12 is permeated.
  • the contact switch S 1 is closed. If, on the other hand, the stylus 8 is deflected by the lower thread 5 according to FIG. 7 in the axial direction of the hook shaft 2, the movable leg 8f is lifted off the contact pin 12 and thus the contact switch S 1 is opened, as shown in FIG. 7.
  • the probe bracket 8 is provided with at least one bend 8g, which, however, runs according to FIG. 4 in a plane lying parallel to the stitch plate 3, so that the probe bracket 8 is just drawn in FIG. 4.
  • This kink 8g serves as a guide for the lower thread 5, so that it cannot deflect laterally when it is deflected by the hook plate 1a in the axial direction of the hook shaft 2, for example by sliding along the feeler arm 8. This ensures that a deflecting movement of the lower thread 5 reliably results in an opening movement of the probe bracket 8.
  • FIGS. 5 and 8 show that the guide groove 16a in the bearing block 16 runs parallel to the needle plate 3.
  • this guide groove 16a is oblique in accordance with the main deflection direction of the lower thread 5, i.e. formed at an acute angle to the level of the throat plate 3 in the bearing block 16. This results in more favorable movement conditions, which have the advantage that a smaller force is required to deflect the feeler 8 because the direction of force and the direction of deflection are approximately the same.
  • a round looper 1 of an embroidery, quilting or sewing machine is shown, which is fastened on a looper shaft 2, which rotates twice, for example, per machine revolution, the lower thread being scanned with every second looper revolution.
  • the scanning takes place by means of a device which is arranged below a stitch plate 3, which is partially shown in section in FIG. 14 and which has a stitch hole 3a for a needle 4.
  • a lower thread 5 can be seen within this tap hole 3a, which is drawn off from a bobbin case 6 of the round hook 1.
  • the round gripper 1 is provided on its cylindrical outer circumference with a gripper plate 1a, the development of which is shown in FIG. 11. With the help of this looper plate 1a there is a deflection of the lower thread 5 in the axial direction of the looper shaft 2 per revolution of the round gripper 1. This deflection of the lower thread 5 is scanned to determine whether a lower thread 5 is properly present, which comes from the bobbin case 6 through the tap hole 3a leads through to the embroidery material 7 and is knotted on the underside thereof with the upper thread, not shown.
  • the device for monitoring includes a probe bracket 8, which is freely rotatably mounted in its bearing block 15 fastened to the underside of the needle plate 3.
  • a probe bracket 8 which is freely rotatably mounted in its bearing block 15 fastened to the underside of the needle plate 3.
  • one end of the stylus 8 is shaped into an eyelet 17, which is inserted into a slot 18 of the bearing block 15 and held there with a pin 19.
  • the probe bracket 8, which consists of ferromagnetic material, has an angled portion 8g in the region of an outlet opening 20 on the bobbin case 6, on which the lower thread 5 is supported.
  • the free end 21 of the stylus 8 extends substantially parallel to the throat plate 3 beyond the circular gripper 1 into the area of a proximity initiator 22 which is fastened under the throat plate 3. Lines 23 go from the proximity initiator 22 to an electronic circuit, not shown.
  • the free end 21 of the probe bracket 8 is guided between the round gripper 1 and the proximity switch 22 in a bracket 24, the two bracket ends 25, 26 define stops for the deflection of the probe bracket.
  • the bracket end 26 is arranged such that the free end 21 of the probe bracket 8 is in contact with this bracket end 26 immediately in front of the proximity switch 22, but does not touch it.
  • the device shown works as follows: when the round hook 1 rotates, the hook plate 1a deflects the lower thread 5 in the axial direction of the hook shaft, as shown in FIG. 13.
  • the free end 21 of the probe bracket 8 reaches the area of the bracket end 25, which serves as a stop.
  • the free end 21 of the stylus 8 is removed from the proximity switch 22.
  • the signal of this switch, not shown, is designated S2 in FIG. 10.
  • the proximity initiator 22 emits a signal designated S1 in FIG. 10.
  • the total scanning area extending over an angle of rotation of 26 ° is denoted by d1 in FIG. 10.
  • the proximity initiator 22 opens prematurely in this scanning area d1, as indicated in the signal S1 in FIG. 10, there is no thread breakage, since such a signal can only be emitted if the stylus 8 is deflected by a properly present lower thread and thus its free thread End 21 is removed from the proximity switch 22. If, on the other hand, the stylus 8 remains in its functional position shown in FIG. 12, there is a thread break because the signal S1 then has a profile, as shown in the lower part of FIG. 10.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Sewing Machines And Sewing (AREA)
EP85110198A 1984-09-05 1985-08-14 Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine Expired EP0173897B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE8426133U 1984-09-05
DE19848426133 DE8426133U1 (de) 1984-09-05 1984-09-05 Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine
DE8518089U 1985-06-21
DE19858518089 DE8518089U1 (de) 1985-06-21 1985-06-21 Vorrichtung zur Überwachung des Unterfadens einer Stick- Stepp oder Nähmaschine

Publications (2)

Publication Number Publication Date
EP0173897A1 EP0173897A1 (de) 1986-03-12
EP0173897B1 true EP0173897B1 (de) 1988-05-18

Family

ID=25950026

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85110198A Expired EP0173897B1 (de) 1984-09-05 1985-08-14 Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine

Country Status (3)

Country Link
EP (1) EP0173897B1 (enrdf_load_stackoverflow)
DE (1) DE3562785D1 (enrdf_load_stackoverflow)
GR (1) GR852009B (enrdf_load_stackoverflow)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3732834A (en) * 1971-04-23 1973-05-15 N Mayer Bobbin runout signalling device
US4429651A (en) * 1979-08-06 1984-02-07 Tokai Kogyo Mishin Kabushiki Kaisha Device for detecting absence of a thread in a sewing machine

Also Published As

Publication number Publication date
GR852009B (enrdf_load_stackoverflow) 1985-12-24
DE3562785D1 (en) 1988-06-23
EP0173897A1 (de) 1986-03-12

Similar Documents

Publication Publication Date Title
DE19833508A1 (de) Nadelwählvorrichtung, insbesondere zur Auswahl der Rippnadeln in Rundmaschinen zur Herstellung von Strick- und Strumpfwaren oder dergleichen
DE2516488A1 (de) Einrichtung zur bruchueberwachung eines fadens oder garnes
EP0173897B1 (de) Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine
DE2024122C3 (enrdf_load_stackoverflow)
DE3432527A1 (de) Vorrichtung zur ueberwachung des unterfadens einer stick-, stepp- oder naehmaschine
DE2616738C3 (de) Doppelsteppstich-Nähmaschine mit umlaufendem Greifer
DE2024122A1 (de) Vorrichtung an Textilmaschinen zum Ab stellen bei Fadenbruch oder Auslauf der Vor lagespule
CH642328A5 (de) Vorrichtung zur ueberwachung der fadenzufuhr bei textilmaschinen.
EP1194625B1 (de) Fadenliefergerät mit gewichtsentlastetem absteller
DE69204337T2 (de) Umlaufender Greifer.
EP1143056B1 (de) Fadenführer für Flachstrickmaschinen
DE8426133U1 (de) Vorrichtung zur Überwachung des Unterfadens einer Stick-, Stepp- oder Nähmaschine
CH660202A5 (de) Spinn-zwirnmaschine.
DD263549A5 (de) Vorrichtung zum feststellen eines fuer den schuetzendurchgang geschlossenen fachs in einer wellenfach-textil-webmaschine
DE3632208C2 (de) Zweinadel-Steppmaschine
DE614876C (de) Vorrichtung zur Verhuetung von Fehlstichen an Doppelsteppstich-Naehmaschinen
DE2934544C2 (de) Anordnung an einer automatischen Spulmaschine
EP0310820B1 (de) Fadenspeicher- und -liefervorrichtung für Textilmaschinen, insbesondere Strickmaschinen
EP4474554B1 (de) Fadenliefergerät
DE8518089U1 (de) Vorrichtung zur Überwachung des Unterfadens einer Stick- Stepp oder Nähmaschine
EP3066247B1 (de) Vorrichtung zur überwachung des schifflifadens auf einer gross- oder klein-schifflistickmaschine
EP0461332B1 (de) Schiffchen für Stick- und Steppmaschinen
DE2439214C3 (de) Spulengehäusehaltevorrichtung für Doppelsteppstichnähmaschinen mit umlaufendem Greifer
DE19924595C1 (de) Nickhebel-Anordnung für eine Zwirnmaschine
DE1802330A1 (de) Signaleinrichtung,insbesondere fuer Waschmaschinen oder Trockenmaschinen

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR IT

17P Request for examination filed

Effective date: 19860319

17Q First examination report despatched

Effective date: 19870513

D17Q First examination report despatched (deleted)
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR IT

REF Corresponds to:

Ref document number: 3562785

Country of ref document: DE

Date of ref document: 19880623

ET Fr: translation filed
ITF It: translation for a ep patent filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19980720

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19990914

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20000428

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20010501