(19)
(11) EP 0 056 619 A2

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
28.07.1982 Bulletin 1982/30

(21) Application number: 82100222.7

(22) Date of filing: 14.01.1982
(51) International Patent Classification (IPC)3D04B 15/80
(84) Designated Contracting States:
DE FR GB

(30) Priority: 20.01.1981 IT 2052681 U

(71) Applicant: LONATI S.p.A.
I-25123 Brescia (IT)

(72) Inventor:
  • Lonati, Francesco
    I-25100 Brescia (IT)

(74) Representative: Modiano, Guido, Dr.-Ing. et al
Modiano & Associati S.r.l. Via Meravigli, 16
20123 Milano
20123 Milano (IT)


(56) References cited: : 
   
       


    (54) Yarn feeding finger control device for a circular knitting machine, in particular a single cylinder hose knitting machine


    (57) For selectively controlling yarn feeding fingers (2) in a circular knitting machine the yarn feeding fingers (2) whereof are individually pivoted to a stationary structure (4) and movable between a rest position and an operative one, with the drive ends (2b) of the feeding fingers (2) there are associated respective electromagnets (11) the movable armatures (12) whereof act as by thrust application on the respective drive ends (2b) of the yarn feeding fingers (2). The selective energization of the various electromagnets (11) is accomplished through a memory device driven by a photoelectric unit located astride a disk formed with peripheral notches and made rigid with the machine main drum. Each forward step movement of the drum results in the sending of one or more pulses from the photoelectric unit to the memory device, wherein the knitting program is stored such that for each pulse or number of pulses there correspond an energization or de-energization control impulse to a given electromagnet (11).




    Description


    [0001] This invention relates to a yarn feeding finger control device for a circular knitting machine, in particular a single cylinder hose knitting machine, comprising a plurality for yarn feeding fingers individually pivoted to a stationary structure of the machine and selectively movable between a rest position, whereat one yarn feeding end thereof is moved away from the needles and the respective yarn is not picked up by the latter, and an operative position, whereat said end is moved close to the . needles and the latter pick up the yarn, the selective movement being accomplished through program controlled means.

    [0002] Devices of the above general type are well known to the experts, e.g. from US Patents No.s 1,763,378 and 1,938,673. The means for selectively actuating the yarn feeding fingers comprise in general a plurality of cams arranged circumferentially around a machine drum in accordance with the yarn feeding fingers program for operation, and a system of levers and tie rods arranged between the cams and respective yarn feeding fingers.

    [0003] A device of this kind requires, therefore, as many cams along the drum periphery as are the yarn feeding fingers. Assuming a machine with plural feeds, there are to be found as many groups of cam rows as are the feeds, thus resulting in a drum of considerable bulk. Moreover, the linkage system is also bulky as well as being complex, since each set of levers and tie rods associated with a yarn feeding finger must be indipendent of the others.

    [0004] This situation remains substantially unaltered where the tie rods are replaced with Bowden cables, as it is usual with double cylinder machines.

    [0005] A primary object of this invention is to provide a drive device of the type indicated in the preamble, which is significantly less bulky than conventional ones, requires virtually no space around the periphery of the machine main drum, or any other drums thereof, and can bring about less advancement movements of the drum on behalf of other' machine controls.

    [0006] Another object of the invention is to provide a device of the type mentioned in the preamble, which can even be controlled, instead by the machine drum, by some other programming means.

    [0007] .These and other objects, such as will be apparent hereinafter, are all achieved by a yarn feeding finger control device for a circular knitting machine of the type mentioned in the preamble, characterized in that with the yarn feeding fingers there are associated respective electromagnets for moving said yarn feeding fingers, and that a means is provided for detecting the movement of a mechanical programming member of the machine, as well as a memory device electrically connected to said detecting means and driven thereby to selectively energize and de-energize individual electromagnets in accordance with the advancing movement of 'said mechanical programming member of the machine.

    [0008] Advantageously, the mechanical programming member may be the machine main drum, and the detecting means may comprise a photoelectric unit adapted for sending electric pulses to the memory device at each advance step of the drum, the memory device controlling, selectively and sequentially, the energization and de-energization of the individual electromagnets and, accordingly, the intervention and withdrawal of the various yarn feeding fingers in accordance with the pulse sequence from the photoelectric unit.

    [0009] In a device of this type, the machine main drum (or other equivalent drum) no longer requires, to drive the yarn feeding fingers, any cams along its periphery and can thus be made smaller in size or utilized to drive other machine members, thus extending the knitting capabilities of the machine. It will be sufficient, for example, to provide a disk rigid with the drum and having a peripheral arrangement of plural notches for each advancing movement of the drum during a full revolution, the notch succession supplying, during the drum advancing movement and through a pair of photo-elements in the photoelectric unit, electric pulses for driving the memory. In the memory, there is stored the knitting program, and the driving of the memory by the detecting means causes each given pulse, from a setting or reference position or upon completion of ascertain number of pulses starting from that position, to produce an energization or de-energization control impulse for a given electromagnet, thus controlling to knit or withdrawing from knitting the respective yarn feeding finger. It will be appreciated, therefore, that all of the lever and tie rod and/or Bowden cable systems are eliminated, thus leaving a significant clear space peripherally to the machine and facilitating access to parts thereof. The electromagnets easily find room under the yarn feeding fingers. If desired, the ends of the yarn feeding fingers associated with the electromagnets may be bent outwardly from the plane of movement of the yarn feeding fingers, should the available room for the electromagnets prove insufficient.

    [0010] Further details and advantages of the invention will be more readily apparent from the following detailed description of one embodiment thereof, illustrated in the accompanying drawings, where:

    Figure 1 is a perspective view of a yarn feeding finger group according to the invention;

    Figure 2 is a perspective view of the detecting means associated with the machine drum;

    Figures 3 and 4 show one yarn feeding finger and the electromagnet associated therewith, respectively in the operative and inoperative positions; and

    Figure 5 is a block diagram of the memory device intervening between the detecting means and yarn feeding fingers.



    [0011] As shown more clearly in Figure 1, a feeding group 1 of a circular knitting machine, in particular a single cylinder hose knitting machine, comprises a plurality of yarn feeding fingers 2 individually pivoted at 3 to a structure 4, in turn secured to the stationary portion of the machine (not shown). The yarn feeding fingers 2 are each provided, in a manner known per se, with a work end 2a, formed with guiding means in the form of holes or small tubes 5 for a respective yarn 6, the end 2a being movable between a rest position (Figure 4), whereat the end 2a is moved away from the needles 7 and the related yarn 6 is not picked up by them, and an operative position (Figure3) whereat said end 2a is moved closer to the needles 7 and the latter pick up the yarn 6. The reference numeral 8 designates a yarn guiding plate having holes 9 ' therein for the individual yarns 6 which are supplied from bobbins or reels, not shown.

    [0012] The control ends 2b of the feeding fingers, opposed to the work ends2a, are urged by respective springs 10 (for clarity reasons, only one of them has been represented in Figure 1) stretched between the ends 2b and stationary structure'4 such as to hold the yarn feeding fingers 2 normally in their rest positions. Advantageously, the ends 2b of the yarn feeding fingers which are located on either sides of the middle or center feeding finger are bent outwardly to extend in different planes from the movement planes of the respective yarn feeding fingers 2. This in order to permit electromagnets 11 to be arranged at these ends, in particular below them, as shown in Figure 1. For space reasons, the electromagnets 11 are staggered in several rows, e.g. with two of them further outboard and three further inboard along the radial direction of the machine. They are secured to the structure 4 by means not shown and act on the yarn feeding fingers 2 with their respective rod armatures 12, which urge the yarn feeding fingers 2 from their rest positions (Figure 4) into their operative ones (Figure 3) upon energization of the electromagnets 11. With the yarn feeding fingers 2 in their rest positions, the electromagnets 11 are de-energized and the armatures'12 drawn back.

    [0013] According to the invention, for controlling the yarn feeding fingers, that is to selectively energize and de-energize the individual electromagnets 11, provision is made for a means13 for detecting the movement of a mechanical programming member of the machine, in particular of the machine main drum 14, as shown in Figure 2, and a memory device 15, illustrated in block diagram form in Figure 5, which is electrically connected to the detecting means 13 through leads 16 and driven by such means to selectively energize and de-energize the individual electromagnets 11 as a function of the advancing movement of the mechanical programming member 14.

    [0014] For the detecting means, a disk 17 rotatively rigid with the drum 14 on one side thereof and provided peripherally with a plurality of notches 18, and a photoelectric unit 19, secured to straddle the disk 17 to a holder 20, are provided. The notches 18 are preferably equispaced and in a multiple number of the advancing steps of the drum, e.g. five notches per advancing step of the drum. The photoelectric unit 19which comprises a photoemitter element and photoreceiver one, of a type known per se, is, mounted stationary with respect to the disk 17, and is connected to the memory device 15 through the cited leads 16. It will be appreciated that each advancing step of the drum 14, which is conventionally driven by means of pawls, not shovm, results in the supply of one or more electric pulses to the memory device 15, depending on the number of notches 18 which move past the photoelectric unit 19 during each advancing step of the drum.

    [0015] The pulses are passed to the memory device 15 through a peripheral interface adapter 21, of a type known per se.. The memory device 15 contains a knitting program in accordance wherewith, to the sequence of pulses from the detecting means 13 starting with the zero or setting time and up to the time when knitting commences on the machine, there correspond a sequence of selective energization and de-energization impulses to the electromagnets 11.

    [0016] The device 15 essentially comprises a microprocessor 22, a pair of random access memories (RAM) 23,24, a read-only memory (ROM) 25, and some peripheral interface adapters 26,27,28, in addition to the cited adapter 21. Also provided is a keyboard 29 for program writing, which is connected to the group through the adapter 26, while a display unit 30, connected to the group through the adapter 27, enables the machine rpm to be displayed visually. The group control output is represented by the adapter 28, which controls a number of amplifiers 31, whereto the electromagnets 11 are connected respectively through the leads 32. The group of elements just described is fed through a power supply 33 or battery 34, the microprocessor 22 being driven by a crystal oscillator 35. The device components are respectively connected through the connections 36 and 37, the former being the data bus and the latter the address bus.

    [0017] The microprocessor 22 will process and check the data from the machine, as well as those set on the keyboard 29, in accordance with the machine knitting program, and compare them upon occurrence to those in the various storage devices. More specifically, the read-only memory 25 contains the basic program, which is each time adapted to suit specific knitting requirements by means of the random access memories 23,24. Thus, the device is made extremely versatile and suitable for a high number of knitting programs.

    [0018] The various components of the device are electronic components which are readily available " on the market, and will require no further discussion herein, also because the memory device just described is not a part of this invention.

    [0019] In actual practice, the device will be set for knitting by writing on the keyboard 29 the knitting program, in the sense that each advance movement of the drum 14, in turn related to the progressive number of revolutions of the machine and accordingly to each pulse or series of pulses from the detecting means 13, is made to correspond to a state of energization or de-energization of each electromagnet 11 in accordance with the knitting program. Thereafter, the yarn feeding fingers 2 are automatically selected in accordance with the knitting instant. In other words, each time that a pulse is supplied by the detecting means 13, the memory device 15 will hold or change the state of one or more electromagnets 11 in accordance with the preset program. It should be noted that with the drum 14 at a standstill, the controls to the electromagnets are maintained. Of course, they may also be maintained during the motion of the drum 14, if the stored program does require it. It is also noteworthy that the fine distribution of the notches 18 affords the possibility of providing several controls within a single advancing step of the drum in very quick succession. Thus, one is enabled to select with a high accuracy the time instant of insertion to knit of a yarn feeding finger 2 and time instant of withdrawal from knitting of another yarn feeding finger 2. In all cases, the operation of the memory device 15 affords high simultaneous control number capabilities with even a single pulse, whereas conventional machines would require, for the same purpose, the provision of a high number of separate mechanical elements on the drum.

    [0020] With the device described hereinabove, it also becomes possible to readily modify the knitting program, by simply setting a different program with the aid of the random access memories 23,24 and keyboard 29, whereas a conventional machine would require that a large number of cams be replaced on the drum, which is a critical and time-consuming operation.

    [0021] It will be appreciated from the foregoing that the inventive device can bring about a considerable reduction in the drum bulk. In fact,' this device requires no space availability around the drum periphery, and the electronics can be easily enclosed in a case or box of small dimensions, which can be mounted at any convenient location on the machine.

    [0022] Of course, the mechanical programming member which cooperates with the detecting means may be other than the machine main drum, and be, for example, the machine main chain.

    [0023] This device, as described in the foregoing, is obviously equally applicable on single cylinder machines and double cylinder or cylinder and dial machines.


    Claims

    1. A yarn feeding finger control device for a circular knitting machine, in particular a single cylinder hose knitting machine, comprising a plurality of yarn feeding fingers (2) pivoted individually to a stationary structure (4) of the machine and selectively movable between a rest position whereat one yarn guiding end (2a) thereof is moved away from the needles (7) and the respective yarn (6) is not picked up thereby, and an operative position whereat said..end (2a) is moved closer to the needles (7) and the yarn (6) is picked up thereby, the selective movement being accomplished by program controlled means, characterized in that with the yarn feeding fingers (2) there are associated respective electromagnets (11) for moving the yarn feeding fingers (2), and that a means (13) is provided for detecting the movement of a mechanical programming member (14) of the machine, as well as a memory device (15) electrically connected to said detecting means (13) and.driven thereby to selectively energize and de-energize individual electromagnets (11) in accordance with the advancing movement of said mechanical programming member (14) of the machine.
     
    2. A device according to Claim 1, characterized in that said mechanical programming member. (14) is the machine main drum, and that said detecting means (13) comprise.s a photoelectric unit (19) adapted for supplying electric pulses to said memory device (15) at each advancing step of said drum (14), the memory device (15) being effective to selectively and sequentially control the energization and de-energization of individual electromagnets (11) in accordance with the pulse sequence from said photoelectric unit (19).
     
    3. A device according to Claims 1 and/or 2, characterized in that said detecting means (13) comprises a disk (17) rotatively rigid with said drum (14) on one side thereof and formed with a plurality of peripheral notches (18), and a pair of photoelements arranged to be stationary with respect to said disk (17).
     
    4. A device according to Claim 3, characterized in that several notches (18) are provided for each advancing step of said drum (14).
     
    5. A device according to one or more of the preceding claims, characterized in that the yarn feeding fingers (2) arranged alongside a center yarn feeding finger (2) have control ends -( 2b), opposedly located to the yarn guiding ends (2a), arranged on further outboard planes, different from the planes of movement of the respective yarn feeding fingers (2), and that said electromagnets (11) are staggered in several rows.
     
    6. A device according to one or more of the preceding claims, characterized in that said electromagnets (11) are provided with rod armatures (12) effective to apply a thrust action on said yarn feeding fingers (2).
     
    7. A yarn feeding finger control device for a circular knitting machine, in particular a single 3 cylinder hose knitting machine, substantially as 4 herein described and illustrated.
     




    Drawing