US3509738A

US3509738A - Knitting machines

Info

Publication number: US3509738A
Application number: US682856A
Authority: US
Inventors: Karl Flad
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-11-15
Filing date: 1967-11-14
Publication date: 1970-05-05
Anticipated expiration: 1987-05-05
Also published as: ES347039A1; FR1545073A; ES364360A2; GB1200468A

Description

y 970 v FLAD KNITTING MACHINES 4 Sheets-Sheet 1 Filed Nov. 14, 1967 INVENTOR lflRL FLAW ATTORNEY;

May 5, 1970 v K. FLAD 3,509,738

; KNITTING MACHINES Filed Nov. 14, 1967 r I 4 Sheets-Sheet 2 Fig. 4

INVENTOR mm. FLA Q ATTORNEYS 4 Sheets-Sheet 5 Filed Nov. 14, 1967 Fig.5

Fig.6

INVENTOR KARL FLA (D ATTORNEYJ K. FLAD' KNITTING MACHINES May 5, 1970 4 Sheets-Sheet 4.

Filed Nov.'l4', 1967 INVENTOR. KARL FLAD 3,509,738 KNITTING MACHINES Karl Flad, 7411 Undingen Hauptstrasse 29, Undingen, Germany Filed Nov. 14, 1967, Ser. No. 682,856 Claims priority, application Germany, Nov. 15, 1966, F 50,681; July 19, 1967, F 53,005 Int. Cl. D0411 15/66 US. Cl. 66154 24 Claims ABSTRACT OF THE DISCLOSURE A knitting machine having a needle selecting device which is simultaneously guided against the rear ends of jacks which displace the needles, wherein there is provided electro-magnetically held strikers, each of which can be moved to a position in which the striker engages the rear end of a jack or into another position where it misses the rear end of a jack. The position of the individual jacks are stored in an information carrier which can be read electrically or optically by a read-out unit. The information carrier, unlike known Jacquard machines which employ metal cards, has a width which is small in comparison to the operating width of the knitting machine.

This invention relates to knitting machines and is more particularly concerned with a knitting machine having a needle selecting device which is guided periodically against the rear ends of jacks displacing the needles and which has electro-magnetically actuated striker members each of which is movable into a position in which it engages the rear end of a jack and into another position in which it misses the rear end of the jack.

In known Jacquard machines the control of the jacks is effected by means of the so-called Jacquard cards. These are metal strips which have the same length as the operating width of the machine and as many strips are linked together as the Jacquard pattern has courses. Before the slur cock or cam is guided along the needle bed, the card is presented to the ends of the jacks. At each point at which the card has no recess, the respective jack end rests on the card and is moved by the movement of the card into a position in which it is engaged by the slur cock. At the points at which recesses are provided in the card, the jacks remain in their rest position and are, therefore, not engaged by the slur cock.

These Jacquard cards must be produced heretofore from steel strips. Their production is extremely time consuming and expensive, and as a rule very expensive special machines are necessary for this purpose. Placing together the Jacquard cards required for the individual courses to form a complete pattern plan is also time consuming because the cards must be connected to each other by means of steel spring rings. Finally, the insertion of the cards into the automatic Jacquard machines is an extremely laborious, difiicult and time consuming operation. These circumstances have an extremely disadvantageous effect in practice, because a knitting manufacturer must invest a great deal of capital and time in the cards before he can produce even a piece of sample fabric and can assess the effect of the pattern or design. It may also happen that the sample piece must be discarded right away and with it also the Jacquard card, or the sample piece does not meet with approval, and in this case also the whole investment involved in the pattern card has been expended in vain.

Attempts have been made to avoid these disadvantages in a known knitting machine in that a special patterning device is substituted for the Jacquard cards. This known patterning device is provided with a housing in which United States Patent 3,509,738 Patented May 5, 1970 plates are pivotally mounted which can be moved into two end positions in such manner that during periodic forward movement of the device against the rear jack ends, the plates located in the one position meet the jack ends, whereas the plates located in the other position miss the jack ends. In this known device the plates are held in the one position by a pawl which can be actuated by an electro-magnet which is guided transversely over all plates. This electro-magnet is energized when it is located above those plates which are to be selected. Whenever the electro-magnet is located above plates which are not to select the jacks associated therewith, the magnet remains unenergized. The impulses for thus purpose are derived from a drum which extends over the whole length of the apparatus, that is to say, it extends over the Whole operating width of the machine, and its surface is provided with conductive and nonconductive points corresponding to the desired pattern, the points being sensed by a contact arm attached to the magnet as the latter is guided over the plates, that is, is moved along the whole operating width of the machine.

This apparatus has, first of all, the disadvantage that the magnet must be guided along the apparatus before the knitting machine knits each course, for the purpose of selecting the needles. This movement cannot take place simultaneously with the movement of the slur cock of the machine because after the selection of the plates the patterning device must first be moved against the rear jack ends in order that the jacks are set. Only thereafter can the slur cock be guided along the needle bed. The machine operates thus very much more slowly than the known machines which use Jacquard cards. A further disadvantage resides in the fact that first a drum must be produced on which the pattern is represented. Since, however, the length of this drum corresponds to the operating width of the machine, the manipulation and production of this drum is very much more cumbersome and expensive than the manipulation and production of the Jacquard cards referred to above so that the disadvantages of this known apparatus are much greater than the disadvantages of the above mentioned Jacquard cards.

The invention has as an object to avoid the disadvantages of the above mentioned machines. The invention consists in that the positions of individual jacks are stored in an information carrier which can be read electrically or optically and the width of which is small in comparison with the operating width of the knitting machine, that a read-out device is provided which converts each information contained in the carrier into an electrical signal, and that each jack is associated with an electro-magnet which responds to the signal and which effects the adjustment of a striker adapted to co-operate with the respective jack.

Thus, the information carrier is no longer used directly for advancing the individual jacks which are to be made operative, but this task is preformed by a unit which responds to the signal read-out of an information carrier. Since, however, the carrier must only travel through the read-out device, but need not transmit a movement to the jacks, the information carrier of the apparatus according to the invention can consist of a soft material such as is generally known for information carriers in data processing. Any knitting machine operator can insert desirable information into such a carrier by means of a simple and inexpensive punching device so that the operator or manufacturer himself can produce a control card for a desired Jacquard pattern at any time and in a simple manner. The production of a piece of sample fabric therefor, does no longer require a large financial investment, and the operator or manufacturer does not run a great risk. He himself can modify a pattern with a few manual operations. Finally, he need not insert heavy pattern cards of metal into the knitting machine in a long and difficult operation, but it is sufficient that he removes a strip of paper or card, possibly even a strip of a synthetic resin, from the read-out device and inserts a new one thereon.

Read-out devices for information stored in a carrier are commercially available. Preferably inserting information into the carrier is effected by means of perforations so that the operator can see exactly what information he has entered. In known read-out devices, these perforations can be converted into electrical signals, either indirectly by optical means, or directly by electrical means. Admittedly, the apparatus according to the invention is more expensive than a single Jacquard card of steel. However, in the known machines such as a metal strip or card is required for each individual course. For example, for a Jacquard pattern comprising 40 courses, 40 punched metal strips are required each of which extends over the Whole operating width of the machine. If, furthermore, the fact is considered that an automatic Jacquard machine must be provided with new pattern cards several times within a season, and if the fact is taken into account that only a single sample piece is produced with some pattern cards, when a sample piece does not meet with approval upon inspection, it will be clear that the annual expenditure which is connected with the known J acquar cards of metal is extremely high so that amortisation of apparatus which can remain permanently on the machine and which is controlled only by perforated cards or other paper strips, is effected in a very short time.

In one embodiment of the invention the read-out device is selected so that the information for a defined portion of the width of the machine is stored on the information carrier in a row transverse to the conveyance direction of the latter. The information for the next-following portion of the machine width is disposed in the next row of the information carrier. Thus, if the operating width of the automatic Jacquard machine is, for example, 150 cm., each row of the information carrier may store the information for a section of for example 30 cm. or 50 cm. of the operating width of the machine. Thereby clarity is increased and inspection is facilitated. In this case, a plurality of information rows of the information carrier which is, for example, a perforated card, must then be scanned by the read-out device for the purpose of adjusting one course.

In one embodiment, a rail is provided which extends over the whole operating width, that is to say, along the Whole needle bed, and which is guided periodically against the rear ends of the jacks. The rail is provided with recesses or perforations into which the rear ends of the jacks can enter which are to remain at rest. Each recess is associated with an electro-magnetically operable flap which covers this recess in one position and thereby forms a striker co-operating with the jack end. This embodiment of the invention has the advantage that elements controlled by the read-out device must produce only a control movement which is utilised for covering or uncovering recesses. The power necessary for displacing the jacks is provided by a machine part in a known manner. The rail corresponds in this case to the known Jacquard card, but with the difference that in the present case the sequence of the open and covered recesses is changed after The invention is not limited to the fact that the part which co-Operates with the rear jack end has the form of a plate, but it may consist of any kind of striker or actuator the position of which depends upon the excitation of a magnet.

In a particularly preferred embodiment of the invention a drive for moving the strikers is provided which is independent of the energisation of the electro-m'agnets. A particular advantage of the invention resides in the fact that in this case the electro-magnets each of which is associated with a striker or actuator serveonly for temporarily retaining the strikers in one end position, and the magnets can, therefore, be dimensionsed very small. Thus, it is possible to use the patterning device according to the invention also with modern knitting machines having a very fine needle pitch. The power necessary for moving the strikers is provided, for example, by a shaft which rotates synchronously with the machine and which moves the strikers by means of cam discs. In this case, the electro-magnet may affect directly a member attached to or forming part of the striker so that in the position of the striker in which this member rests on the pole piece of the magnet, the striker is held directly by the magnet. In another case, the magnet may prepare a catching device for receiving a striker moved by the independent drive, and the striker is held by the catching device in its one end position. In either case the power provided by the magnet is very small.

In one embodiment of the invention the strikers are held in close contact with the drive during the movement into the end position in which they are thereafter held by means of an electromagnet. This has the advantage that all the strikers are securely displaced at the same speed and are guided into an exactly defined end position. The movement of the strikers into the other end position can be effected in various ways. Thus, for example, in one embodiment of the invention the strikers are moved by the periphery of a rotating cam disc into the one position in which they can be held by means of an electromagnet; when it is held by the magnet the striker disengages itself automatically from the drive because it does not follow any more the periphery of the cam disc while being retained by the magnet. The return movement may be effected by means of a spring which is disposed on the striker and which becomes effective when the magnet is switched off. In one embodiment of the invention, these springs are conveniently used to press a member attached to or forming part of the strikers against the periphery of a rotating cam disc of the independent drive. In a particularly preferred embodiment of the invention the striker is constructed in the form of a two-armed pivotally mounted lever, the one arm of which is pressed by a spring against the periphery of a cam disc of the drive and the other arm of which is arranged to be engaged by the electro-magnet. In this case the face of the striker coming in to engagement with the magnet in the one end position can rest without an air gap against the pole piece of the magnet. Thereby the power required for holding the striker in the one end position is particularly small.

In all the above mentioned embodiments of the invention latching or locking devices may be provided in accordance with a further embodiment of the invention, and at least in the position in which the strikers engage the ends of the jacks, these devices hold the strikers securely against the jack ends while the rail is advanced, the latter, in turn, being driven independently of the pattern plan. In this embodiment of the invention the electro-magnet must hold the strikers securely only until the latching or locking device has fixed the striker in its position. This embodiment of the invention also contributes to keeping the power small which must be provided by the electromagnet. In this embodiment of the invention a magnet which is to hold a striker in a position appropriate to the energized state of the magnet must thus be switched on at the instant at which the striker is moved towards the mag net by the motorised drive. The magnet can be switched off again at the instant at which the latching or locking device engages the striker. The latching or locking device is driven in synchronism with the movement of the strikers.

In the embodiment of the invention in which the electro-magnets do not affect directly the striker or a member attached thereto, but affect for example a catching device, the magnets must be energized only until the catching device is ready for holding the striker. This time interval can be shorter than the time interval which elapses until a latching or locking device engages a striker held by the electro-magnet.

In the subject of the invention the information carrier constituting the pattern plan is read optically or electrically by a readout device. Reading out can be effected in a known manner, either in parallel, that is to say, simultaneously for all the magnets or, however, successively in time. In the parallel read-out method, as many read-out members are needed as electro-magnets are provided. -In this case a relatively long time interval is available for reading out and for adjusting the magnets. In the series read-out method each course must be scanned sucessive ly in the time stitch by stitch within the period of time available for the adjustment of the magnets. The advantage of this read-out method consists in that only a single sensing element and an associated electronic circuit arrangement are required the latter delivering the respective pulse to the striker magnet associated with the pattern point. The control pulse is relatively short in the case of this series read-out method. In one embodiment of the invention, the magnets associated with the individual strikers are each provided with a core of high remanence. It is preferable in this case, that the part of the striker forming the armature of the magnet consists of a magnetically polarisable material, that is to say of a magnetically hard material. In this case the core is polarised by a short pulse in the one sense. After the short pulse has decayed, that is to say after the excitation of the electro-magnet has ceased, the high remanence of the core causes the magnetic flux to continue with the same polarity. If, then, the striker or a member which is rigidly attached thereto and which is magnetically polarised approaches the core, the striker either continues to approach and eventually to adhere to the pole pieces even after the switching pulse for the electro-magnet has ceased, or the striker will be repelled if it is of opposite polarity. When the striker is to be moved into its other position, the winding of the magnet receives a pulse of opposite direction.

In all embodiments of the invention in which the striker is returned to its starting position by spring force, the spring force is selected so that it cannot remove the striker from the magnet as long as the magnet is energized, or as long as the remanent flux concurs with the flux of the polarised armature attached to or forming part of the striker.

Additionally to the spring force, the magnet may receive a short pulse of opposite polarity independently of whether the core of the magnet has a particularly high remanence or not, for the purpose of repelling the striker from the magnet. This is, in particular, preferable when the magnets affect directly members which consist of a magnetically hard material, for example steel, and which, therefore, retains a quite considerable remanence even after an operating pulse has ceased. The polarity of the electro-magnet is reversed by the repelling pulse so that the member which serves as an armature and which because of itse remanence still has the previous polarity is repelled with certainty.

A further possibility for ensuring that the member attracted by and resting on the magnet is repelled with certainty consists in that during the time interval in which a striker is locked in a selected position, the member resting against the magnet is de-magnetised by an alternating current field of decreasing strength. The pole of the respective magnet may possibly be penetrated also by this alternating field. When the latching or locking device releases the striker a very weak spring is then suflicient for withdrawing the demagnetised member from the pole which has also been de-magnetised.

If the magnet does not affect directly the displaced striker, but affects a catching device the preceding statements apply to the respective member which rests against the pole of the magnet.

Owing to the close disposition of the magnets when the needle bed is finely divided, it is preferable to polarise the magnets so that in the operation a north pole of one magnet is followed in the pole plane by a south pole of the adjacent magnet.

In embodiments of the invention, the magnets may alternatively be disposed directly on the needle bed of the machine needles, and not as in the previously mentioned embodiments on a machine part which is periodically displaced relatively to the needle bed. In this case the magnets affect the jacks in the needle bed directly or by way of inserts.

Finally, embodiments of the invention can be produced in which the electro-magnet affects a coupling means which is inserted between the striker and the drive which is independent of the pattern plan and thereby switches off the drive of the striker in one end position of the latter and switches the drive on again when the striker is to be moved into the other end position.

In known Jacquard knitting machines, a roll or cylinder is usually moved periodically against the rear ends of the jacks, and on the surface of the roll there is disposed the Jacquard card associated with the respective course. This roll is removable in many known knitting machines in order that the Jacquard cards can be inserted more easily. Embodiments of the apparatus according to the invention may have holding means which can be inserted directly into the supporting means for the Jacquard rolls in each known machine so that this apparatus can be interchanged with the known Jacquard rolls. If the known machines are constructed so that during the periodic movement towards the jack ends slide faces which are stationarily attached to the machine engage the Jacquard roll, faces are provided on the apparatus according to the invention which cooperate with these slide faces.

Further features of the invention are clear from the following description of embodiments of the invention in conjunction with the claims and the accompanying drawings. The features may be realised individually by themselves or a plurality thereof may be combined in one embodiment of the invention.

In the drawings:

FIG. 1 is a plan view from above of a section of an apparatus according to the invention, illustrating a rail with recesses and flaps adapted to cover the recesses in accordance with a desired pattern,

FIG. 2 illustrates a section along the line II-II of FIG. 1,

FIG. 3 illustrates an information carrier,

FIG. 4 illustrates a section through another embodiment of the invention,

FIGS. 5 and 6 illustrate details of further embodiments, and

FIG. 7 illustrates a constructional form of a detail of FIG. 4.

FIG. 8 illustrates in partial section the embodiment of FIG. 4 in combination with a schematic diagram showing the read-out device as well as a partial section through a needle base with a needle, a jack rod and a striker.

In the embodiment of the invention illustrated in FIGS. 1 and 2 a steel rail 1 is attached to the machine part of an automatic Jacquard machine which wouldbe used in a known automatic Jacquard machine to displace the Jacquard card against the rear ends of the jacks in order to push some thereof in a forward direction. The rail has an approximately U-shaped cross section.

Recesses

2 and 3 which are square in the present example, but may alternatively be round or rectangular, extend through the yoke of the cross section, and their mutual spacing corresponds to the spacing between the ends of the jacks in the needle bed. The row of recesses 2 is associated with the upper jacks in the needle bed, the row of recesses 3 is associated with the lower jacks. One upper and one lower jack are associated with each needle. The number of

recesses

2 and 3 in each row corresponds therefore to the number of needles present in the needle bed.

The limbs of the rail 1 are provided with bearings 4 in each of which a striker in the form of a cranked lever for each recess 2 and each recess 3 is pivotal about an axis 7. The forward end of the arm 5 of each cranked lever is constructed in the form of a flap 8 which when the cranked lever is pivoted inwardly can completely cover the

recess

2 or 3, respectively. The arm 6 of each cranked lever is either itself constructed as an armature for an electro-magnet 9', or however such an armature is attached thereto. The electro-magnet 9 is in the form of a U-shaped magnet. However, it may alternatively be constructed in the form of a rod magnet if a return path of the magnetic field lines is provided in some other manner. A spring 10 keeps the cranked lever and thus the flap 8 away from the region of the

recess

2 or 3 as long as the magnet 9 is not energized FIG. 2 illustrates on the right-hand side the position of the flap 8 when the magnet 9 is energized; in this position the flap 8 covers the recess 3; on the left-hand side the position is illustrated in which the flap 8 releases the recess 2, when the magnet is not energized.

The yoke of the U-shaped cross section of the rail 1 may be V-shaped so that the flaps 8 lie flat on the upper surface of the rail and need not perform a movement parallel to the surface during their inward pivotal movement. In this case, the end portion of the flaps 8 may be provided with a wedge-shaped enlargement 12 so that in the closed position of the recess the face turned towards the jack ends 13 extends perpendicularly to the direction of the rail movement which is indicated by the double arrow 14. When the rail is pushed upwardly in the direction of the arrow 14, the jack 13 with which the covered recess 3 is associated is pushed forward, whereas the jack 13 with which the uncovered recess 2 is associated enters in this recess 2 and remains in its rest position when the rail 1 is pushed upwardly. Leads 11 extend from the magnets 9 to a commercially available read-out device which, however, is not illustrated. This read-out device connects leads 11 associated with flaps 8 which are to cover a recess in the rail 1, to a voltage source for the duration of one operating step of the automatic Jacquard machine. The information which determines which recesses 2 and 3 are to be covered, is taken by the read-out device in the present example from a perforated card 15 in which the information for a certain number of flaps is contained in a row 16 disposed transversely to the conveyance direction 17 of the card. The information is represented by the presence or absence of a recess 18. In the illustrated embodiment of the invention it may be assumed that the needle bed extending over the operating width of the machine possesses 400 needles. These 400 needles correspond to one row of loops or course, and they are associated with 800 jacks so that the perforated card which is used as information carrier in the present embodiment must contain 800 items of information. The perforated card may consist of thin card or strong paper or of a foil of synthetic resin. In order that the pattern can be monitored more easily on the perforated card 15, the 800 items of information are disposed in a plurality of individual rows 16, for example in 16 rows each having 50 items of information. In this case a row contains therefore the information relating to the upper or lower jacks of one eighth of the operating width of the machine. The

individual cards 15 for each course of the pattern are linked together or connected to each other by connecting members of any kind, for example even by adhesive strips or the like.

The embodiment just described indicates only the principle of all embodiments of the invention which can be produced. The invention may be realised in many ways utilising elements known for machine control.

In place of perforated cards, other information car riers may alternatively be used, for example carriers which contain information in the form of optically detectable signals, for example in the form of darkened or blackened points or areas which are translated into electrical pulses in the read-out device. This embodiment of the invention has the advantage that information carriers can be produced directly by photo-mechanical means from a drawing of the pattern by photocopying or the like. For example such pattern drawings can be copied on transparent foil in a manner known per se, the foils then being used in the read-out device for effecting the control. Alternatively, the information can be stored on a magnetic tape.

In the embodiment of the invention illustrated in FIGS. 4 to 6 there is provided a needle base NB having longitudinal slots S wherein needles N are mounted so as to be longitudinally displaceable. In the proximity of one end of the needles N, there is provided thereon a butt B projecting from the surface of the needle. A jack 24, extending in a longitudinal direction and being axially aligned with the needle, is provided for each needle N, and each jack 24 is likewise movable in the direction of the longitudinal axis of the needle. A look SC is disposed along the surface of the needle base NB and is movable at right angles to the axis of the needles. The lock SC has a guiding groove C on its side facing the surface of the needle base. Two displaceable strikers 21 for each pair of jacks 24 disposed above them are mounted pivotally about bearing pins 22 in a rail 20, the ends of the strikers 21 adjacent to the jack ends being cranked approximately at right angles and forming thereby striker faces 23. Two shafts 25 with cam discs 26 are disposed on the rail 20 on either side of the web-like centre member 27 of the rail 20. Electra-magnets 29 have U-shaped cores 31, each core being provided with an energizing winding 30, and are attached to the rail 20. The pole faces 32 of the cores 31 are disposed so that the lever arm 28 of the striker 21 in its one position comes to rest on the respective pole face 32 without a substantial air gap. The energizing winding 30 of each electro-rnagnet 29 is connected to a readout A device which scans optically or electrically a pattern plan contained on the information carrier 15. and appropriately sets the strikers 21 in accordance with the pattern plan for each course of the fabric to be knitted.

The read-out device A comprises a light source 2 fed by a source of current Ba. When the information carrier 15 has a perforation at the respective place, light from the light source Q impinges on a photoconductive cell F through a lens Li. The photoconductive cell F is connected to battery Bb and also to a relay R. The second terminal of the relay R is connected to the second terminal of the battery Bb. When light has impinged on the photoconductive cell F, the resistance thereof is reduced, and the relay R attracts and closes a contact K which then connects the electro-rnagnet 29 with the battery Bb so that electro-magnet receives current. If, however, there is no perforation at the scan place of the information carrier 15, then the photoconductive cell F does not receive any light and the relay R remains de-energized, so that no current is fed to the electro-magnet 29.

The lever arm 33 of the striker 21 remote from the striker face 23 is pressed against the periphery of the cam disc 26 by compression springs 34 disposed in the centre member 27. The shafts 25 rotate in synchronism with the movement of the slur cock of the knitting machine, and therefore also in svnchronisrn with the machine part which presses the rail 20 periodically against the jack ends 24. During a revolution the cam disc 26 pivots the arm 33 of the striker 21 in the direction towards the centre member 27 of the rail 20. The spring 34 holds the arm 33 in contact with the periphery of the cam disc 26 and returns the striker 21 to its starting position if or when the electro-magnet 29 is switched off.

During the reciprocatory pivotal movement of the striker 21, the arm 28 comes to rest in the one position against the pole face 32 of the electromagnet 29. If, at this instant, the energizing winding 30 is switched on the arm 28 is retained in this position and the striker 21 re mains stationary in this position, because the spring 34 is not strong enough to return the striker 21 to its rest position illustrated in the drawing while the magnet 29 is energised. In this position in which the arm 28 thus rests against the pole face 32, the striker face 23 is located outside the range of the rear end 24 of the respective jack, so that when the rail 20 is pushed forward against the rear jack ends the jack associated with the energize electro-rnagnet is not engaged by the striker face 23 and is, therefore, not pushed forward during the advance movement of the rail 20.

If, however, there is no perforation at the scan point of the information carrier 15, then the electro-magnet 29 is not energized and cannot retain the arm 28, which under the biasing of the spring 34 pivots the striker back into the position shown in FIG. 8 after the cam disk 26 assumes the position as illustrated in FIG. 8. If the rail 20 is now moved toward the jack 24, then the surface 23 of the striker engages the rear end of the jack and moves it forward a distance a. The jack in turn advances the needle N a distance corresponding to the spacing a. Thus, the butt B assumes a position wherein it can be engaged by the groove C of the lock SC. The rail 20 is thereafter returned and then the knitting operation can properly begin. During the knitting operation, the lock SC extends at right angles to the plan of the drawing of FIG. 8 moving along the surface of the needle base and engaging those needles whose butt B is in the range of the groove C of the lock SC.

A support 35 is disposed on each side of the centre member 27 of the rail 20 and is displaceable in the di rection towards the rear ends of the arms 33 of the strikers 21. The supports 35 are driven synchronously with the shafts 25 and the machine part which causes the rail 20 to advance. On each of the supports 35 there are fixed one or more U-shaped members having limbs 36' and 36" the ends of which cooperate with a recess 37 at the rear end of each lever arm 33. In the rest position illustrated in the drawing, the end of limb 36' engages the recess 37; in the other position (not illustrated) of the striker 21 the end of limb 36" engages in the recess 37. When a

limb end

36 or 36" engages the recess 37, the striker 21 is rigidly locked in the one or in the other position. The supports 35 are advanced-against the rear ends of the lever arms 33 for the purpose of locking the latter at the instant at which the shaft 25 has completed a revolution and the striker 21, the associated magnet 29 of which has not been energised during the respective operating step, has been returned to its rest position by the respective spring 34. As soon as the support 35 with the U-shaped members has locked the striker or strikers 21, the electro-magnets 29 which were switched on during the rotation of the shaft 25 can be switched off again. The shaft 25 and the support 35 remain at rest as long as the striker faces 23 rest against the rear ends of the jacks 24 during advance of the rail 20.

After the knitting operation has been completed, all the needles N and the jacks 24 are returned to their starting position and then the information carrier 15 is moved one step further. In FIG. 8, the scanning operation is shown for one point only, but in reality, an entire field of points is simultaneously scanned and the signal of each point is fed to a corresponding electro-magnet 29.

In embodiments of the invention it may be preferable to prevent magnetic stray flux from extending through the jack ends 24. This can be attained in that the displaceable strikers 21 which in the embodiment illustrated in FIG. 4 are constituted by two armed levers, consist in accordance with FIG. 5 of a non-magnetisable material and carry a ferr0-magnetic insert 38 in the region of the magnet poles. In the embodiment of the invention illustrated in FIG. 6 the striker 21 consists admittedly of a ferromagnetic material. However, a non-magnetisable insert 39 is inserted into the striker faces 23 cooperating With the jack ends 24. Finally, in a third embodiment of the invention, the jacks can be produced from a non-magnetic material. A plurality of these measures or even all three together may be realised in one embodiment in order to restrict the magnetic flux to the magnets and the parts of the apparatus acting as magnet armatures.

As mentioned above, the magnets in the invention serve merely as holding magnets and therefore can be constructed relatively small. A further reduction in size of the electro-magnets is possible if, as in another embodiment of the invention, the part serving as armature of the magnet rests without air gap against the pole face of the magnet when the armature is attracted. It has been described above that for removing the remanence and for repelling the armature, a pulse of opposite direction is passed through the winding of the electro-magnet. However, it is not absolutely necessary that this magnetic flux directed in opposition to the remanence is produced in the winding by a pulse of opposite direction; in embodiments of the invention it may alternatively be preferable for various reasons to eliminate the remanence in some manner, for example by a pulse applied to a second winding, by an alternating field of decreasing strength, or by other measures. By repelling the armature from the magnet pole in such manner it is possible to provide springs 34 which have only a small spring force.

The strikers 21 may be constructed alternatively as sliders instead of levers. Moreover, the apparatus can be constructed so that it can co-operate with more than two rows of jacks, for example with three or more rows disposed above each other. Each jack end is associated in this case also with a striker 21, the apparatus having then a slightly modified construction.

FIG. 7 illustrates an alternative form of construction of the eccentric drive constituted by the shaft 25 and cam discs 26 of FIG. 4. In this construction the shaft is made from two parts. A dove-tail like longitudinal groove 41 is produced in a shaft 40 of larger diameter, and a correspondingly shaped shaft 42 of smaller diameter is pushed into the groove and thereafter fixed therein. In this manner an eccentric cross section of the shaft 26 can be produced simply and economically.

What I claim is:

1. A knitting machine with a needle selecting device which is simultaneously moved against the rear ends of jacks displacing the needles, said needle, selecting device also being provided with striker means adapted to be moved into a position in which the rear ends of said jacks are engaged and a position in which the rear ends of said jacks are missed, an information carrier means for storing the desired positions of each of said jacks and which can be read out electrically or optically, and a read-out means for said information carrier means, wherein the improvement essentially comprises:

said information carrier means being relatively small as compared to the operating width of said knitting machine;

information bits being stored on said information carrier means in a digital manner; electro-magnetic means for holding said striker means associated with each of said jacks;

said electro-magnetic means being operatively connected with said read-out means and operable to be switched on and off in accordance with the informa- 1 1 tion readout from said information carrier means by electrical signals produced by said read-out means; and drive means for moving said striker means, said drive means being independent of the excitation of said electro-magnetic means.

2. A machine according to claim 1, wherein said information carrier means consists of perforated cards, said perforated cards being linked together, and each perforated card containing information for one course.

3. A machine according to claim 1, wherein said information carrier means contains the information for a portion of the needle bed, said information being disposed in a row transversely to the feed direction of said information carrier means, and the information for successive individual sections being disposed in successive rows in the feed direction.

4. A machine according to claim 3, wherein said information is contained on said information carrier means in the form of optically detectable signals.

5. A machine according to claim 4, wherein black areas are provided on the information carrier means which contain said optically detectable signals.

6. A machine according to claim 1, wherein said needle selecting device includes a rail extending along the entire needle bed and being simultaneously guided against the rear ends of said jacks, said rail having recesses for the entry of said jacks into said rail, and each of said recesses being associated with an electro-magnetically operable flap which, in one end position thereof, covers said recesses and forms said striker means cooperating with the rear end of each of said jacks.

7. A machine according to claim 6, wherein each said electromagnetically operable flap is disposed on said rail.

8. A machine according to claim 1, wherein said device has a rail of non-magnetisable material, two-armed levers associated with each of said jacks being pivotally mounted about a common axis which extends lengthwise through said rail, wherein the ends of each of said levers cooperating with the rear ends of said jacks, respectively, project beyond the forward end face of said rail and form the selectable striker means for the ends of said jacks, said electro-magnetic means being disposed on said rail, and said last-mentioned means affecting the individual levers.

9. A machine according to claim 8, wherein said lastmentioned means are polarized in such a manner so that adjacently disposed poles of mutually adjacent electro magnetic means have dissimilar polarities.

10. A machine according to claim 8, wherein there is provided means for locking said striker means, and said electro-magnetic means, said striker means, said drive means and said locking means forming a constructional unit which is interchangeable with the roll provided in known knittingmachines which carry the Jacquard cards.

11. A machine according to claim 6, wherein there is provided means for locking said striker means at least:

while said rail is pressed against said jack ends in the engagement position in which said striker means cooperate with said jack ends, and said locking means being independent of the pattern plan and being driven synchronously with the movement of said striker means. i

12. A machine according to claim 11, wherein said striker means are connected to said drive means by cam and cam follower means while said striker means are displaced into the one end position in which they can be held by said electro-magnetic means. I

' 13. A machine according to claim 12, wherein spring means are provided for driving said striker means during their movement from said one end position in which they can be held by said electromagnetic means into the other end positon.

14. A machine according to claim 12, wherein spring means are provided for pressing said striker means against the periphery of said cam.

15. A'machine according to claim 1, wherein each of said striker means compri es a two-armed pivotally mounted lever, the end of said lever remote from the jackcontacting surface of said striker means being engageable by a locking means, a cam disk engaging one said lever armand said electro-magnetic means engaging the other said lever arm.

16. A machine according to claim 15, wherein said other lever arm of each of said striker means arranged to engage said electro-magnetic means rest in one said end position of said striker means in direct contact with the pole face of said electro-magnetic means.

17. A machine according to claim 16, wherein said electro-magnetic means is provided with a core which has a high remanence and is adapted to be reversely polarized by a pulse dependent on the pattern plan, and a portion of said striker means constituting the armature of said electro-magnetic means comprises a magnetically polarized material.

18. A machine according to claim 17, wherein said jack-contacting surface of said striker mean constituting the striker face consists of non-magnetisable material and carries a ferro-magnetic insert in the region of the magnetic pole.

19. A machine according to claim 1, wherein an insert of non-magnetisable material is disposed in the jackcontacting surface of said striker means.

20. A machine according to claim 19, wherein said jacks consist of a non-magnetisable material.

21. A machine according to claim 17, wherein for the purpose of repelling the portion of said striker means constituting the armature of said electro-magnetic means and for the purpose of removing the remanence, a magnetic flux is produced in said electro-magnetic means which is directed in opposition to the flux with which said striker means had been held against said electromagnetic means during the selection process.

22. A machine according to claim 16, wherein said surface re ting against said electro-magnetic means is exposed to an alternating field of decreasing strength for the purpose of destroying the remanence.

23. A machine according to claim 11, wherein the energizing current of said electro-magnetic means for holding said striker means against said electro-magnetic means during the selection proce s is switched off as soon as said locking means has locked said striker means in position.

24. A machine according to claim 10, wherein said drive means for moving said striker means include essentially an eccentric shaft which is comprised of a cylindrical shaft having a longitudinal groove of dove-tail cross-section and a shaft having a shape corresponding to said longitudinal groove and having a diameter smaller than said first-mentioned shaft and being inserted in said longitudinal groove.

References Cited UNITED STATES PATENTS 1,795,235 3/1931 Ruinnet 6675 2,072,969 3/1937 Tandler 66154 2,153,342 4/1939 Ruinnet 66-75 2,157,989 5/1939 Lawson 66 2,173,488 9/1939 Tandler Ct 61 66 75 XR 3,035,426 5/1962 M66 n66n 66-154 XR 3,292,393 12/1966 Riblel 66154XR 3,313,128 4/1967 Schmidt 66-154 3,365,916 1/1968 11115161 6161 66154 XR 3,370,443 2/1968 B6n116 61 61 66154 3,375,681 4/1968 Monk 66154 FOREIGN PATENTS 1,251,516 12/1960 Fran 66.

75 RONALD FELDBAUM, Primary Examiner