US3780542A - Needle breakage safety device - Google Patents

Needle breakage safety device Download PDF

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Publication number
US3780542A
US3780542A US00305398A US3780542DA US3780542A US 3780542 A US3780542 A US 3780542A US 00305398 A US00305398 A US 00305398A US 3780542D A US3780542D A US 3780542DA US 3780542 A US3780542 A US 3780542A
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US
United States
Prior art keywords
carriage
safety device
needle
disengaging
shift lever
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 - Lifetime
Application number
US00305398A
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English (en)
Inventor
H Schieber
E Krause
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.)
Henkel Dorus GmbH and Co KG
Original Assignee
Dr Rudolf Schieber GmbH and Co KG
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
Application filed by Dr Rudolf Schieber GmbH and Co KG filed Critical Dr Rudolf Schieber GmbH and Co KG
Application granted granted Critical
Publication of US3780542A publication Critical patent/US3780542A/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04B—KNITTING
    • D04B35/00—Details of, or auxiliary devices incorporated in, knitting machines, not otherwise provided for
    • D04B35/10—Indicating, warning, or safety devices, e.g. stop motions

Definitions

  • ABSTRACT A device for disengaging the sliding carriage of a knitting machine is response to a needle break.
  • the high amplitude sound caused by a break is sensed by a microphone attached to the machine frame, and the amplitied output of the microphone toggles a threshold trigger whose amplified output energizes an electromagnet.
  • the latter releases a spring biased lever which in turn moves a shift rod to disengage the carriage drive.
  • Means are also provided for deactivating the safety device when the carriage leaves the needle re gion, thereby preventing triggering from the noise caused by racking or carriage reversal.
  • the present invention relates to a needle breakagev safety device on knitting machines, said device responding to .a shockwave occurring when a needle breaks and switching the disengaging device for the sliding carriage of the knitting machine via an electronic amplifier.
  • Prior art To safeguard against damage resulting from needle breakage, knitting machines, more particularly straight and circular knitters, are generally provided with safety devices which either switch off the knitting machines after needle breakage or prevent the sliding carriage from passing through again in order to avoid any further breakage of needle feet. Such further breakage may result from damage which occurred when the first needle broke. Stopping the carriage also avoids any damage to the upper and lower needle beds, or in the case of a rotary knitting machine, to the cylinder or rib disc.
  • Safety devices operating on the principle of an impact safety mechanism have previously been used with straight and circular knitting machines.
  • overload levers are mounted on the sliding car,- riage entrainment of the drive means.
  • the shock-from the breakage of a needle causes these levers to tilt sideways and to activate an electrical disengaging device.
  • a known safety device intended to solve this problem comprises devices mounted on each needle bed of a straight knitting machine. These devices transmit the impact produced by the needle breakage to a diaphragm by means of a free swinging weight. The diaphragm itself releases switches for activating the disengaging devicefor the sliding carriage of the machine.
  • This type of safety device at least two monitoring devices are required for each knitting machine, since one monitoring device has tobe mounted on each needle bed in the direction from which the shock resulting from needle breakage will come. This safety device is not suitable for rotary knitting machines.
  • the object of the present invention is to obviate the disadvantages of known needle breakage safety devices and to create a simple and reliable needle breakage safety device which may be used for both straight and.
  • a needle breakage safety device wherein a microphone is mounted on the members of the'knitting machine bearing the needle beds to pick up. sound waves.
  • the microphone is connected toan electronic switch- 2 ing circuit responding to the high amplitude produced by a needle breakage,-and the switching circuit is connected to the disengaging device for the knitting machine.
  • the device according to the invention is simple in construction and has the advantage that the sound waves can be monitored by a microphone mounted in a desired position and in a desired direction on the member bearing the needle beds.
  • the high amplitude caused by the needle breakage causes the electronic switching circuit to trigger and this in its turn activates the disengaging device by way of an electronic amplifier or relay.
  • the microphone is advantageously attached to the member about which the cylinder and rib disc of the knitting machine'r'otate.
  • the electronic switching circuit is advantageously a bistable stage with follow up amplification, for example, in the form of a relay.
  • An advantageous development of the needle breakage safety device consists in that a switching device is provided for the synchronized interruption of the connection between the microphone and the disengaging device each time the sliding carriage leaves the region of the needles.
  • FIG. 1 is a front view of a straight knitting machine
  • FIG. 2 is a side view of a needle board of a straight knitting machine with'a sliding carriage disposed on it and provided with a microphone;
  • FIG. 3 is a perspective view of a rotary knitting machine having a microphone attached to it;
  • FIG. 4 shows a normal sound wave and a high amplitude wave which occurs suddenly as a result of 'a needle breakage
  • FIG. 5 is a block diagram of the electronic circuit between the microphone and the disengaging device
  • FIG. 6 shows an electromagnetic device for releasing the disengaging device in the blocked state
  • FIG. 7 shows the device of FIG. 6 in the released state.
  • FIG. 1 shows a front view' of a straight knitting machine to which the needle breakage safety device according to the invention can be applied.
  • a sliding earriage 13 is connected-to a chain 14.
  • the chain 14 is driven by a chain wheel 15, which is connected via coupling means (not shown) to a drive mechanism (not shown).
  • FIG. 2 shows a side view of a needle bed having a sliding carriage disposed on it
  • a needle bed support 1 is attached to the machine frame 16.
  • a microphone 2 which receives sound waves transmitted by the needle bed, is mounted on the needle bed support 1. These sound waves are produced by the passage of the needles and rods through the lock in the sliding carriage 13. They are picked up by the microphone 2 and converted into electrical signals or oscillations. A high amplitude oscillation occurs when a needle breaks. This leads to the releasing of the disengaging device for the sliding carriage of the knitting machine in order to prevent further damage to the needles and the needle beds by the passage of the sliding carriage subsequent to the first needle breakage.
  • FIG. 4 shows a time plot .of a sound oscillation which may occur in the needle bed support 1.
  • the reference number represents a high amplitude oscillation which is produced in the needlebed support 1 when a needle breaks. As stated above, this high amplitude oscillation 5 is sensed by the microphone 2 and used to release the disengaging device for the sliding carriage.
  • a switching device is provided for the synchronized interruption of the connection between the microphone 2 and the disengaging device each time the sliding carriage leaves the region on the needles.
  • the region beyond the needles is designated by x.
  • the connection between the microphone or monitoring device 2 and the disengaging device for the sliding carriage is broken.
  • the sliding carriage enters the region containing the needles the interrupted connection is restored. In this way the sounds produced during the switching of a racking mechanism or by the sliding carriage stops, for example, do not release the disengaging device unnecessarily when the sliding carriage 13 is positioned beyond the region of the needles.
  • FIG. 3 shows a perspective view of a rotary knitting machine in which a microphone 2 is mounted on a member 1 about which the cylinder and the rib disc of the rotary knitting machines rotate.
  • FIG. 5 shows a block diagram of an electrical circuit.
  • the disengaging device for the sliding carriage of the knitting machine is released by way of this circuit in response to a high amplitude oscillation 5 picked up by the microphone 2.
  • the microphone is connected via an electronic amplifier 6 to a bistable stage 7 in the form of a Schmitt trigger switch-having an adjustable threshold value.
  • the bistable stage 7 acts on a relay 8, which in turn acts on an electromagnet 9 of the disengaging device for the sliding carriage via a switch 3.
  • the sound oscillations produced during the passage of the needles and rods through the lock of the sliding carriage 13 are also picked up by the microphone 2 and converted into electrical oscillations.
  • the bistable stage 7, whichreceives its input from the electronic amplifier 6, is held in its one position as long as the sound oscillations 4 are constant and do-not exceed the thresholdlevel shown in FIG. 4.
  • the bistable stage 7 switchesinto its second 1 sliding carriage 13 to a standstill.
  • the connection between the microphone 2 and the disengaging device is interrupted in synchronism with the knitting machine operation each time the sliding carriage leaves the region of the needles and it is restored again when the sliding carriage 13 enters the region of the needles.
  • the electromagnet 9 which is supplied with power via the switch 3, is mounted on the machine frame 16. It acts on a lever 10 which holds a spring-loaded lever 11 against the spring tension as long as the electromagnet is not energized. When the spring-loaded lever 11 is in this position a shift rod 12 is held in such a position that a coupling (not shown) connected to the chain wheel 15 is engaged.
  • a needle breakage safety device for knitting machines including a needle bed support member, a movable carriage cooperable therewith, drive means for the carriage, means responsive to a needle break for producing an electrical signal, means for amplifying the signal, and means responsive to the amplified signal for disengaging the drive means from the carriage, the im provements characterized by:
  • the means responsive to a needle break for producing an electrical signal comprising a microphone mounted on the needle bed support member for sensing the high amplitude sound caused by a needle break, and an electronic threshold switching circuit for producing an output only in response to such high amplitude sound, said output being connected to the amplifying means.
  • a safety device as defined in claim 1 wherein the switching circuit comprises a bistable stage having an adjustable threshold level.
  • a safety device as defined in claim 1 further comprising means'synchronized with the movement of the carriage for disabling the safety device whenever the carriage leaves the region of the needles.
  • a safety device as defined in claim 4 further comprising means synchronized with the movement of the carriage for disabling the safety device whenever the carriage leaves the region of the needles.
  • the disengaging means comprises an electromagnet energizedby the amplifying means, a pivotally mounted releasing lever adapted to be rotated by the electromagnet, a pivotally mounted, spring biased shift lever held in a first position by the releasing lever and rotatable to a second position upon release, and a shift rod displacenet, a pivotally mounted, spring biased shift lever held in a first position by the releasing lever and rotatable to a second position upon release, and a shift rod displaceable by the shift lever for disengaging the carriage drive means when the shift lever rotates to its second positlon.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Knitting Machines (AREA)
US00305398A 1972-02-10 1972-11-10 Needle breakage safety device Expired - Lifetime US3780542A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2206363A DE2206363A1 (de) 1972-02-10 1972-02-10 Nadelbruchsicherungsvorrichtung

Publications (1)

Publication Number Publication Date
US3780542A true US3780542A (en) 1973-12-25

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Family Applications (1)

Application Number Title Priority Date Filing Date
US00305398A Expired - Lifetime US3780542A (en) 1972-02-10 1972-11-10 Needle breakage safety device

Country Status (6)

Country Link
US (1) US3780542A (ja)
JP (1) JPS5122980B2 (ja)
DE (1) DE2206363A1 (ja)
FR (1) FR2171731A5 (ja)
GB (1) GB1362488A (ja)
IT (1) IT968130B (ja)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4156357A (en) * 1978-09-05 1979-05-29 The Singer Company Carriage releasing mechanism for a flat bed knitting machine
US4790153A (en) * 1986-11-13 1988-12-13 H. Stoll Gmbh & Co. Safety device for flat-bed knitting machines
CN101260594B (zh) * 2008-04-23 2010-06-09 孙平范 针织横机安全报警装置
CN101424007B (zh) * 2007-10-30 2011-07-27 H.斯托尔两合公司 探测装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3711439A1 (de) * 1987-04-04 1988-10-20 Sipra Patent Beteiligung Messgeraet zur bestimmung des betriebswirkungsgrades einer maschine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4156357A (en) * 1978-09-05 1979-05-29 The Singer Company Carriage releasing mechanism for a flat bed knitting machine
US4790153A (en) * 1986-11-13 1988-12-13 H. Stoll Gmbh & Co. Safety device for flat-bed knitting machines
CN101424007B (zh) * 2007-10-30 2011-07-27 H.斯托尔两合公司 探测装置
CN101260594B (zh) * 2008-04-23 2010-06-09 孙平范 针织横机安全报警装置

Also Published As

Publication number Publication date
DE2206363A1 (de) 1973-08-23
FR2171731A5 (ja) 1973-09-21
JPS5122980B2 (ja) 1976-07-14
GB1362488A (en) 1974-08-07
JPS4891365A (ja) 1973-11-28
IT968130B (it) 1974-03-20

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