EP0335099A1 - Selector of bimorphous piezoelectric cell type for needles of textile machine - Google Patents

Selector of bimorphous piezoelectric cell type for needles of textile machine Download PDF

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Publication number
EP0335099A1
EP0335099A1 EP89102929A EP89102929A EP0335099A1 EP 0335099 A1 EP0335099 A1 EP 0335099A1 EP 89102929 A EP89102929 A EP 89102929A EP 89102929 A EP89102929 A EP 89102929A EP 0335099 A1 EP0335099 A1 EP 0335099A1
Authority
EP
European Patent Office
Prior art keywords
needles
selector
piezoelectric cell
bimorphous
cam
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.)
Withdrawn
Application number
EP89102929A
Other languages
German (de)
English (en)
French (fr)
Inventor
Mario Scavino
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0335099A1 publication Critical patent/EP0335099A1/en
Withdrawn legal-status Critical Current

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Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04B—KNITTING
    • D04B15/00—Details of, or auxiliary devices incorporated in, weft knitting machines, restricted to machines of this kind
    • D04B15/66—Devices for determining or controlling patterns ; Programme-control arrangements
    • D04B15/68—Devices for determining or controlling patterns ; Programme-control arrangements characterised by the knitting instruments used
    • D04B15/78—Electrical devices

Definitions

  • This invention relates to a needle selector for textile machines, in particular for machines used for forming hosiery and knitwear.
  • linear knitting machines are known, the essential part of which is a carriage driven with reciprocating motion and carrying electromagnets to upwardly or downwardly urge bars which engage the butts of needles lying in a fixed bed facing the carriage. These bars are moved by the action of oscillating cams which cause the bars to rise, and with them the needles so that they grip the yarn.
  • Another example of the aforesaid type of machine comprises a series of needles disposed peripherally on a rotary drum and arranged to intercept in known manner the appropriate textile yarns which are carried by known members positioned in the vicinity of said drum. To produce this interception, the needles are moved to a variable height in predetermined sequence to cooperate with the appropriate yarns and thus obtain the required patterns with different stitches and/or colours.
  • the needles are moved by a system of cams which act consecutively on the ends of said needles to lift them and so enable a pointed part carried by each needle to intercept the yarns.
  • a selector device is provided which acts on said ends to prevent the cams operating on those needles which are not required for the chosen pattern, such needles therefore not undergoing any vertical movement.
  • the selector device or more simply selector consists substantially of an oscillating cam of ferrous material pivoted on a pivot and having at the end facing the needle ends or butts a face inclined at a certain angle so that an angular movement of the cam causes the butt to touch the inclined face and become urged inwards so as not to be subjected to the action of the previously stated lifting cams.
  • the oscillating cam is moved upwards or downwards so that the butt does not touch said inclined face.
  • the angular movement of the cam is obtained by electromagnets which when powered by an electric current act on said oscillating cam (moved by an arm pivoted to the centre of the two electromagnets) to cause it to rotate.
  • a further drawback is that in a selector of the said construction the oscillating cam can have only two working positions. Moreover there is the possibility that any metal residues produced by the rubbing of the butts against the inclined surface can be attracted by the electromagnets, so falsifying their operation.
  • An object of the present invention is therefore to provide a selector device for the needles of textile machines of the aforesaid type which obviates the problems connected with known selectors.
  • a selector for use in textile machines in particular for forming hosiery and knitwork and comprising a series of needles disposed peripherally on a rotary drum or on a fixed bed and arranged, when selected, to intercept textile yarns in order to obtain particular patterns and/or colours, characterised by comprising a bimorphous piezoelectric cell of known type clamped at one end between support elements of insulating material and carrying at its free end an arm operating on an oscillating cam which, following the passage of current within said piezoelectric cell and its consequent deflection, acts on said needles to cause their selection and/or deselection to obtain the particular pattern and/or colour required on the finished fabric.
  • Figure 1 shows diagrammatically a hosiery and knitwork machine comprising a series of needles 1 disposed peripherally on a rotary drum 2 and having at one end a butt 3 and at their other end a gripper member 4 for the yarns (not shown) which are carried in known manner by a member (also not shown) positioned in proximity to the drum 2.
  • first and second cam 5, 6 of known type, disposed in any known manner consecutively in the direction of rotation of said drum.
  • first cam 5 withdraws from the drum 2 all the needles 1 without distinction when the butt 3 of these latter slides along said cam 5.
  • the butts 3 which are thus moved outwards for each revolution of the drum 2 are then brought, by the rotation of this latter, into correspondence with the second cam 6 which acts on said butts to raise the needles 1 to the scheduled height at which the gripper member 4 of said needles hooks the textile yarns.
  • a selector 7 which, as explained hereinafter, causes the butts 3 of those needles 1 which are not to be used for the particular pattern and/or colour to retract towards the drum 2.
  • the selector 7 incorporates a bimorphous piezoelectric cell 8 comprising a ceramic bar 9 carrying two current conductors 10 and 11, upperly and lowerly respectively.
  • One end 12 of the cell 8 is inserted between two blocks 13 and 14 of insulating material which are secured to the cell for example by screws 15. Said blocks 13 and 14 act as the support for the cell 8 and are fixed in any known manner (not shown) to a part of the textile machine concerned.
  • an arm 17 comprising for this purpose a fork-shaped end 18.
  • Said arm 17 has that end 19 distant from the end 18 also fork-shaped and cooperating with a fin 20 of an oscillating cam 21 mounted on a shaft 22 supported by members 23 and 24 fixed onto the textile machines.
  • Said cam also comprises a further fin 25 opposite the fin 20 about the shaft 22 and having an inclined face 26 facing the butts 3 of the needles 1.
  • stop member 27 the function of which is described hereinafter and which has a fork-shaped free end 28 acting on the fin 20 of the oscillating cam 21 and its other end 29 fixed to the textile machine.
  • the purpose of the selector 7 is to cause the butts 3 of those needles 1 which are not to be used for the required pattern and/or colour on the finished fabric, and must therefore not cooperate with the cams 5 and 6 and be raised by the second cam 6, to retract towards the rotary drum 2.
  • the fin 20 of the oscillating cam 21 is associated with the stop member which acts by its free end 28 on said fin 20 to limit the rotation of said cam and thus limit the movement of the arm 17 and bimorphous cell 8.
  • Figure 2 shows the selector 7 applied to a different known textile machine of linear type.
  • parts identical to those described in Figure 1 are indicated by the same reference numerals.
  • the fin 25 of the oscillating cam 21 cooperates with a recess 30 in a bar 31 slidable between fixed guides 32 and having one end 33 substantially of C-shape into which a projecting part 34 of the needle 1 is inserted.
  • deflection of the bimorphous cell 8 causes the cam 21 to rotate about the shaft 22 (arrow Z) to thus pull the bar 31 upwards (arrow X) with consequent raising of the needle 1.
  • the response of the piezoelectric ceramics used in the selector 7 of the present invention is from 2 to 4 times faster than the response of actuators comprising electromagnets, where response signifies the time between the giving of the command and the obtaining of the movement.
  • This increased speed means that the drum can be theoretically rotated 2 to 4 times faster with consequently increased machine production, which depends directly on the drum speed. If the drum speed cannot be increased because of limitations posed by other machine members, the greater operating speed of the oscillating cam 21 enables the number of selectors to be reduced by making the same selector operate several needles successively.
  • the force which the ceramic bars can exert by virtue of their deflection is of the order of only a few grams, and therefore two or more bars 9 can be superposed on each other.
  • the proposed arrangement does not produce heat because the ceramics remain cold, and in addition are not affected by vibration or metal residues arising from contact between the fin 25 and the butts 3 of the needles 1.
  • the angular displacement obtained can be used in programming the radial movement of the butts.
  • a microprocessor can be provided to control the operation of the selector.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Knitting Machines (AREA)
EP89102929A 1988-03-02 1989-02-20 Selector of bimorphous piezoelectric cell type for needles of textile machine Withdrawn EP0335099A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT1962088 1988-03-02
IT8819620A IT1215967B (it) 1988-03-02 1988-03-02 Selettore a cella piezoelettrico bimorfa di aghi per macchine tessili.

Publications (1)

Publication Number Publication Date
EP0335099A1 true EP0335099A1 (en) 1989-10-04

Family

ID=11159733

Family Applications (1)

Application Number Title Priority Date Filing Date
EP89102929A Withdrawn EP0335099A1 (en) 1988-03-02 1989-02-20 Selector of bimorphous piezoelectric cell type for needles of textile machine

Country Status (3)

Country Link
EP (1) EP0335099A1 (it)
JP (1) JPH01250452A (it)
IT (1) IT1215967B (it)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2229198A (en) * 1989-03-15 1990-09-19 Nagata Seiki Kk Piezoelectric needle selector for knitting machine
EP0796939A1 (en) * 1996-03-19 1997-09-24 Precision Fukuhara Works, Ltd Piezoelectric needle selection device for knitting machines
ES2178518A1 (es) * 1999-05-31 2002-12-16 Apein S L Dispositivo de accionamiento de las agujas de maquinas de tejer.
ES2206000A1 (es) * 2001-12-17 2004-05-01 Apein, S.L. Mejoras en dispositivos de accionamiento de las agujas de maquinas de tejer.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3995451A (en) * 1971-03-30 1976-12-07 Firma Franz Morat Gmbh Patterning mechanism
EP0210790A2 (en) * 1985-07-24 1987-02-04 Watanabe Kutsushita Kogyo Co. Ltd. Knitting needle driving mechanism of knitting machine
EP0219029A1 (en) * 1985-10-14 1987-04-22 LONATI S.p.A. Device for selecting the needles in a knitting machine, particularly for stockings
EP0235068A1 (en) * 1986-02-18 1987-09-02 Jumberca, S.A. Mechanism for selecting and controlling the raising of needles in circular and flat bed knitting machines, having a plurality of adjacent needles, with electronic programming control

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3995451A (en) * 1971-03-30 1976-12-07 Firma Franz Morat Gmbh Patterning mechanism
EP0210790A2 (en) * 1985-07-24 1987-02-04 Watanabe Kutsushita Kogyo Co. Ltd. Knitting needle driving mechanism of knitting machine
EP0219029A1 (en) * 1985-10-14 1987-04-22 LONATI S.p.A. Device for selecting the needles in a knitting machine, particularly for stockings
EP0235068A1 (en) * 1986-02-18 1987-09-02 Jumberca, S.A. Mechanism for selecting and controlling the raising of needles in circular and flat bed knitting machines, having a plurality of adjacent needles, with electronic programming control

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2229198A (en) * 1989-03-15 1990-09-19 Nagata Seiki Kk Piezoelectric needle selector for knitting machine
GB2229198B (en) * 1989-03-15 1992-09-09 Nagata Seiki Kk Piezoelectric needle selector in a circular knitting machine
EP0796939A1 (en) * 1996-03-19 1997-09-24 Precision Fukuhara Works, Ltd Piezoelectric needle selection device for knitting machines
US5823015A (en) * 1996-03-19 1998-10-20 Precision Fukuhara Works, Ltd. Piezoelectric needle selection device for knitting machines
ES2178518A1 (es) * 1999-05-31 2002-12-16 Apein S L Dispositivo de accionamiento de las agujas de maquinas de tejer.
ES2206000A1 (es) * 2001-12-17 2004-05-01 Apein, S.L. Mejoras en dispositivos de accionamiento de las agujas de maquinas de tejer.

Also Published As

Publication number Publication date
JPH01250452A (ja) 1989-10-05
IT8819620A0 (it) 1988-03-02
IT1215967B (it) 1990-02-22

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