US3695060A - Apparatus for controlling the jacks of knitting machines - Google Patents

Abstract

In a knitting machine, such as a Jacquard controlled knitting machine, in which the needles are selected by means of pivotal plates which are mounted on a reciprocatory plate bed and which are actuated by electromagnetic means energized in accordance with information stored in an information carrier, at least some of the parts cooperating with the electromagnetic means to effect selection of the needles are arranged to be temporarily demagnetized before the plates are released for return to their rest position.

Description

United States Patent Flad [451 *Oct. 3, 1972 [54] APPARATUS FOR CONTROLLING THE J ACKS OF KNITTING MACHINES [72] Inventor: Karl Flad, Hauptstrasse 29, 7411 Undingen, Germany Notice: The portion of the term of this patent subsequent to May 5, 1987, has been disclaimed.

[22] Filed: June 30, 1969 [21] Appl. No.: 837,741

Related U.S. Application Data [63] Continuation-in-part of Ser. No. 682,856, Nov.

14, 1967, Pat. No. 3,509,738.

[30] Foreign Application Priority Data Oct. 2, 1968 Germany ..P 18 00 568.0 June 29, 1968 Germany ..P 17 60 768.0

[52] U.S. Cl ..66/75 [51] Int. Cl. .....D04b 7/28, D04b 15/70, D04b l5/78 [58] Field of Search ..66/25, 36 A, 36 B, 50, 50 A,

[56] References Cited UNITED STATES PATENTS 1,795,235 3/1931 Ruinnet ..66/75 3,2 62,285 7/1966 Begum era; .;......'.66' "s'0' 3,370,443 2/1968 Bentley et a1 ..66/75 x 3,461,690 8/1969 Martinetz et a]. ..66/50 3,492,836 2/1970 B1666 et al. ..66 5 3,141,316 7/1964 McCarthy et al. ..66/154 A 3,509,738 5/1970 Flad ..66/154 A FOREIGN PATENTS OR APPLICATIONS 1,545,073 9/l968 France ..66/154 A Primary Examiner-Wm. Carter Reynolds Att0rneyCraig, Antonelli, and Hill [5 7] ABSTRACT In a knitting machine, such as a Jacquard controlled knitting machine, in which the needles are selected by means of pivotal plates which are mounted on a reciprocatory plate bed and which are actuated by electromagnetic means energized in accordance with information stored in an information carrier, at least some of the parts cooperating with the electromagnetic means to effect selection of the needles are arranged to be temporarily demagnetized before the plates are released for return to their rest position.

19 Claims, 12 Drawing Figures Pmmmnm I91 3.6954060 SHEET 1- [IF 3 v Fig.1

Fig.2

INVENTOR KA R L FLA D ATTORNEY) P'ATENIEBnm 1912 3.695.060

SHEET 3 OF 3 l 117 fl Fig. 5-

Fig.7

APPARATUS FOR CONTROLLING THE J ACKS OF KNITTING MACHINES This application is a continuation-in-part of my copending application Ser. No. 682,856, filed Nov. 14, 1967, now US. Pat. No. 3,509,738, patented May 5, 1970. Attention is also directed to my copending application Ser. No. 802,931, filed Feb. 27, 1969, now U.S. Pat. No. 3,604,219, patented Sept. 14, 1971 for disclosure of a related invention.

This invention relates to apparatus for controlling the jacks of knitting machines such as described in US. Pat. No. 3,509,738.

The applicant has already proposed an arrangement in which the jacks actuating the needles in the needle support of a knitting machine, in particular a Jacquard machine, are controlled by means of an information carrier in which information relating to the positions of the individual jacks in each course is stored, the knitting machine being provided with a rail which extends over the length of the needle support and which is periodically guided against the rear end of the jacks for the purpose of adjusting selected needles, the rail being provided with displaceable strikers which cooperate with the ends of the jacks and which are disposed at one end of plates pivotally mounted on the rail, the strikers being adapted to be moved selectively by means of electromagnets into and/or out of engagement with the ends of the jacks as required by the information stored in the information carrier.

In such apparatus flat Ushaped magnets are used, the plane containing the pole faces of each magnet being adjacent to the respective plate. The lateral distance of the plates from each other is equal to the lateral spacing between the jacks in the needle support and this, in turn, depends upon the gauge of the knitting machine. These spacings are relatively small, even when the gauge of the needle support is relatively large, as for example in the case of an eight-gauge support which has eight needles per inch of knitting width. The higher the gauge number, the smaller are these spacings. Therefore, care must always be taken that the individual magnets affect only the plates associated therewith and an effect on adjacent plates is avoided. For this reason it has already been proposed to produce the plates from a non-magnetizable material and to attach an insert of ferro-magnetic material in the edge of the plates adjacent to the pole face of the magnet. Moreover, it has been found preferable to produce also the rail on which the plates are pivotally mounted from a non-magnetizable material. In order that the plates are reliably guided, it is preferable to construct the rail in a similar manner as the needle supports, that is to say to provide the rail with grooves in which the plates are inserted and in which they perform their pivotal movement. Suitable non-magnetizable material for the production of such rails are, in the first place, steels with austenitic structure, that is to say stainless steels. These steels, however, are difficult to manipulate so that the production costs of such a rail are quite considerable.

In particular in the case of electromagnets which, because of restricted space, must be small and located closely adjacent to each other, the displaceable armature may remain adhering to the stationary part of the electromagnet after the energizing current has been switched off, because a re-set spring attached to the armature is insufiicient to pull the armature ofi against the attraction force produced by residual magnetism. If the reset springs are made stronger, the electromagnets must also be stronger and therefore larger, whereby the apparatus according to the parent application, now US. Pat. No. 3,509,738 would be difficult to realize.

Even if the stationary and the displaceable parts of the magnetic circuit of the electromagnet are made from special soft magnetic alloys some remanent magnetism remains after the energizing current has been switched ofi', and the flux thereof causes the armature to adhere to the core of the magnet and therefore requires an increase of the force of the reset springs which are intended to pull the armature off the magnet. The increased force of more powerful reset springs must be compensated by more powerful electromagnets. More powerful electromagnets, however, take up more space, and with the fine gauges of modem knitting machines difficulties arise for the accommodation of the electromagnets associated with the individual jacks.

When the plates and the rail are produced from ferromagnetic material the plates may also stick in the grooves of the rail in which they are guided, if the plate and the rail have been locally magnetized; in order to avoid interruptions of the operation owing to this sticking of the plates, the re-set springs must also be strengthened, so that they can pull the plates off against the adhesion force.

The invention is based on the problem to avoid the disadvantages referred to above, and to improve the subject matter of the parent application now US. Pat. No. 3,509,738. The problem is solved in accordance with the invention, in that the rail with the plate and magnetizable parts of the magnetic circuit of each of the electromagnets are at least partly demagnetized during the operation.

The particular advantage of the invention resides in the fact that disturbances of the operation owing to residual magnetism (remanence) are avoided. The plates cannot stick in the rail, and the armatures cannot stick to the electromagnets; the return springs can be weaker and therefore the electromagnets can be made smaller, whereby also knitting machines of fine gauges can be fitted with a system for electromagnetic selection of the jacks.

De-magnetization of magnetizable parts of the'magnetic circuit of the electromagnet must be effected periodically after the excitation has decayed. At the same instant, the rail and the plates can also be demagnetized. In a preferred embodiment, however, provision is made that the rail and the plates remain continuously de-magnetized. This is attained by the invention in that an armature rod of non-magnetizable material is disposed at the plates which extends approximately at ri t angles to the longitudinal axis of the plates and at right angles to the pivot axis, the rod carrying in the region of the pole faces of the associated electromagnet an armature disc of magnetizable material.

The particular advantage in this case resides in the fact that the magnetically effective armature is not located directly at the plate and therefore is not disposed between the edges which limit the grooves for the plates in the rail, but is spaced from therail. Therefore, the possibility is provided to guide the magnetic flux also at a spacing from the rail and to arrange the magnet in such manner that its stray flux which may reach the rail cannot produce any disadvantageous effects, even if the rail is produced from a magnetizable material. The magnetic flux is sufficiently isolated from the plate and the rail by the armature rod of non-magnetizable material. The rail, therefore, can be produced from any of the conventional steels which can be manipulated relatively easily. When U-shaped magnets are used, the pole plane of the magnets may extend parallel to the armature rod, that is to say also perpendicular to the longitudinal axis of the plates.

The armature rod may be rigidly connected to the plate. In this case the armature rod performs a pivotal movement relatively to the magnet pole which corresponds to the pivotal movement of the plates, and the armature rod may be attached to the plate in the region of the pivot axis or at a distance from the pivot axis.

In one embodiment of the invention, the armature rod is pivotally attached to the plate at a spacing from the pivot axis of the plate and is axially guided. This embodiment of the invention has the advantage that the armature rod executes substantially only a movement extending in its longitudinal axis and therefore the space requirement is very small.

In one embodiment of the invention, the magnets which are associated with adjacently disposed, that is to say, mutually adjacent plates, are arranged staggered in two mutually offset rows. The magnets of mutually adjacent plates, therefore, can be disposed on different sides of an armature rod which is rigidly or displaceably connected to the plate, mutually adjacent armature rods being disposed either at the same location on their plate, or, however, at different locations, for example in the case of plates constructed as two-armed levers, on different sides of the pivot axis at mutually corresponding spacings. Owing to the fact that not all the magnets are disposed adjacent to each other, but are arranged staggered in two mutually ofiset rows, the apparatus according to the invention can be realized also in the case of knitting machines which have a very fine gauge, for example in the case of a 14-gauge flat bed machine and also in the case of round knitting machines of a corresponding finer gauge.

In one embodiment of the invention, flange-like upstanding edge rails of non-magnetizable material are provided along the edges of the rail accommodating the plates, and guides for the armature rods are provided in the edge rails. Since the rail accommodating the plates consists of a suitable steel and is therefore sufficiently bending-resistant, it is unnecessary to produce the edge rails from a particularly hard material. It is even possible to make this edge rail from a soft non-yielding material, for example aluminum or brass, in which the guides for the armature rods can be produced with little effort and expense. p

In a preferred embodiment of the invention, a plurality of magnets are grouped together to form insert units. Insert units can be handled more simply than individual magnets, so that when a magnet becomes faulty the whole insert unit can be interchanged. For example the magnets disposed along a length of l or 2 inches of the needle support are grouped together to form such an insert unit. This embodiment of the invention may be developed further in the manner that in the case of magnets disposed staggered in two mutually offset rows, only the magnets disposed in one row are grouped together to form an insert unit. Thereby, the insert units become relatively narrow. Therefore, two rows of insert units are provided on the rail between the two edge rails.

In one embodiment of the invention, the insert units may have cassettes which are U-shaped in cross-section and which are open towards the armature rods, the electromagnets being inserted into the cassettes which are provided with connecting terminals for the ends of the windings of the electromagnets.

In embodiments of the invention comprisinginsert units inserted into the rail, at least the terminals for one end of the magnet windings are connected in an electrically conductive manner to terminal parts which are accessible from the outside. If the one ends of all magnet windings are all electrically connected to each other, for example connected to earth, these winding ends of each individual magnet winding need not be accessible from the outside. However, if required, the terminals of these winding ends also may be accessible from the outside. The external terminal parts are preferably in the form of sockets, so that the insert units can be connected to the circuit controlling the electromagnets by means of multiple plugs and an interchange of the insert units can be effected particularly quickly.

De-magnetization of parts of the magnetic circuit of the electromagnets which have become magnetized during the operation of the apparatus may be effected according to one embodiment of the invention in such manner that a cancelling impulse transmitter is provided which is controlled in synchronism with the operating cycle and the output of which is connected to the electromagnets, where in the canceling impulse produced by the canceling impulse transmitter has a magnitude and duration which is sufficient for cancelling the remanent magnetism in the stationary and in the displaceable parts of the magnetic circuit of each of the electromagnets. Similarly, if necessary, the rail and the plates may be de-magnetized by suitably disposed coils which are also connected to the canceling impulse transmitter. The advantages of the invention reside in the facts that the canceling impulse is matched to the properties of the materials of the core and the armature of the electromagnets, or of the rail and the plates and that the residual magnetism is removed thereby to such extent that adhesion forces of too high a magnitude, such as occur with adhesion in the absence of an air gap, are not present any longer after the application of this impulse, so that the return springs for the armature can be made very weak and thus also the electromagnets can be made relatively small; this in turn leads to the advantage that this electromagnetic control of knitting machines can be applied also to machines with very fine gauge and thus very restricted space conditions. The canceling impulse is adjusted in this case in such manner that reverse magnetization in the magnetic circuit of the electromagnet does not take place or not to a substantial extent. Also, a very uniform operation of all electromagnets is obtained in this manner, because in every operating cycle every magnet starts from the same initial state. This is assisted further by the fact that the cancelling impulse is delivered in synchronism with the operating cycle, whereby at the release of the strikers which are held by the electromagnets by means of a mechanical detent device, all armatures can be caused to disengage uniformly and simultaneously, because at this instant cancellation of the remanent magnetism of all magnets has been effected.

In one embodiment of the invention, provision is made that the setting impulse which effects the detention of the strikers by the respective magnets, terminates directly after mechanical detention of the strikers has taken place, and the cancelling impulse follows directly the setting impulse while the strikers are detained. In one embodiment of the invention, the detent means for the strikers is constructed in this case in such manner that the strikers are displaceable slightly in the reset direction. Owing to the fact that the cancelling impulse follows directly the setting impulse, sufficient time is available for performing the cancelation of the residual magnetism before the detention is released. During this period, the strikers can already move away slightly from the electromagnets, whereby uniform disengagement of all strikers is obtained after the removal of the detention.

In a preferred embodiment of the invention, the canceling impulse has an adjustable amplitude and consists of at least one half-wave of the alternating mains supply current. For producing the canceling impulses, it is therefore sufficient to provide a half-wave rectifier which delivers a half-wave voltage from which the respective required portion is tapped off which is conveniently adjustable, for example by means of an adjustable transformer or a potentiometer, to the amplitude required for the core and the armature in accordance with the kind of steel used therefor.

In a preferred embodiment of the invention, the canceling impulse extends in the form of a highly damped oscillation. This embodiment of the invention has the advantage that the cancelling impulse need not be matched exactly to the respective magnetic values and the geometrical dimensions of the armature and of the stationary part of the electromagnetic circuit of the electromagnets because owing to the decreasing oscillation amplitudes, substantially complete deletion of the remanent magnetism can be obtained in any case for any cross-section of the magnetic circuit. In the case of magnetic circuits having soft magnetic parts of difi'erent cross-sections in the magnetic circuit, different field strengths arise dependently upon the crosssectional area, and thus also differently high remanence values occur unless saturation is achieved even for the largest cross-section, which generally is not the case.

When a canceling impulse is used which has the form of a damped oscillation, different cross-sections and different remanence values are just as unimportant as stray fields and production tolerances of the magnetic values and geometrical dimensions of the core and the armature of the electromagnets. In one embodiment of the invention, a capacitor connected in parallel with the winding of the electromagnet may be provided in this case for producing the cancelling impulse. This embodiment has the substantial advantage that no additional circuit measures are necessary to obtain the result that the canceling impulse becomes effective immediately after the end of the setting impulse, because the parallel connected capacitor is charged by the setting impulse and begins to discharge in the form of a damped oscillation through the parallel connected inductance of the electromagnet at the instant when the setting impulse disappears, the frequency of the oscillation depending upon the inductance of the winding and the capacitance of the capacitor. In this manner, very simple and reliable cancellation of the remanent magnetism of the electromagnet is obtained.

Alternatively, the canceling impulse transmitter may be provided as a separate apparatus and is then controlled in synchronism with the operating cycle by a contact member of a main machine shaft. It may alternatively be triggered by a control impulse produced by the read-out device forming part of the information carrier. In a preferred embodiment of the invention, the cancelling impulse transmitter is contained or incorporated in the read-out device and is controlled thereby. The capacitors connected in parallel with the windings of the electromagnets may also be housed in the read-out device, if always the same number of electromagnets is connected to each signal output.

Details and constructional features of the invention may be seen from the following description in which the invention is explained with reference to examples illustrated in the accompanying drawings, in which FIGS. 1 to 4 illustrate two embodiments of the invention with continuously de-magnetized rail and plates, and FIGS. 5 to 10 illustrate arrangements for de-magnetizing, and in which:

FIG. 1 illustrates a cross-section through a rail constructed in accordance with the invention,

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

FIG. 3 illustrates a section along the line Ill-Ill of FIG. 4 through an insert unit in one embodimentof the invention,

FIG. 4 is a plan view of the insert unit illustrated in FIG. 3,

FIG. 5 is a block diagram of the synchronous control of the canceling impulse transmitter,

FIG. 6 is a cross-section through ,a plate bed with magnets attached thereto,

FIGS. 7 to 9 are various impulse diagrams, and

FIG. 10 is a circuit diagram of a cancelling impulse transmitter for producing impulses in the form of a damped oscillation.

FIG. 11 shows a perspective view of the detent rail and plate structure with a detent rail in unlocked position,

FIG. 12 shows a partial cross-section of FIG. 11 with a detent rail in locked position.

In the embodiment of the invention illustrated in the drawings a rail 1 is shown in FIG. 1 in cross-section and extends along the whole operating width of a knitting machine; therefore, it has exactly the same length as the needle support of the machine. This rail is moved periodically against the rear end of the jacks which are guided in the needle support, for the purpose of adjusting the needles. In the upper surface as well as in the lower surface of this rail, transversely extending grooves 2 are provided into which plates 3 are inserted. The plates 3 have striker faces 5 at their ends adjacent to jack ends 4. Each plate 3 is pivotally mounted about an axis formed by a round rod 6 which traverses the rail 1 in its longitudinal center plane. The plates 3 have recesses 7 by means of which they engage over sections of the rod 6 which constitute bearing pins therefor. A strip 8 of suitable material is laid transversely over the edges of the grooves in the rail 1 in the longitudinal center portion thereof and holds the plates 3 in the grooves 2 and in engagement with the rods 6. A tension spring 9 tends to hold the plates in the position illustrated in FIG. 1 in which the striker faces of the plates 3 come into engagement with the rear ends of the jacks 4 and push the jacks forward in the needle support 11 when the rail 1 is moved in the direction of the arrow 10. The rear end of the plates 3 is constructed in such manner that when the rail 1 is moved opposite to the direction of the arrow 10, stationary inclined faces 12 cause the plates to pivot about the axis of the rod 6, against the effect of the tension spring 9. A notch 13 in the rear end of the plate serves for engagement therein of a detent device not illustrated.

The plates 3 and the rail 1 are produced from a conventional magnetizable steel. Flange-like upstanding edge rails 14 of a non-magnetizable material, for example, brass or aluminum are attached along the edges of the rail 1. The inside of these edge rails 14 is provided with grooves 15 which terminate in the grooves 2 and in each of which an armature rod 16 of non-magnetizable material is guided which carries an armature disc 17 of a magnetizable material, preferably soft iron, and which serves as armature for a flat electromagnet 18 disposed between the edge rails 14. The length of the armaturedisc 17 is dimensioned so that it overlaps the poles of the electromagnet 18. The magnetic flux in the armature disc 17 short circuiting the poles of the electromagnet 18 is isolated from the rail 1 and the plate 3 by the non-magnetizable armature rod 16.

Each armature rod 16 extends approximately at a right angle to the longitudinal axis of a plate 3, is longitudinally displaceable in and guided by the recess 15, and is pivotally connected to the plate 3 at a location spaced from the pivot axis formed by the rod 6. Electromagnets 18 of mutually adjacent plates 3 are staggered in two offset rows as illustrated in FIG. 2. Each one armature rod 16 is pivotally connected to the forward lever arm of the one plate, each other armature rod 15' associated with the respective adjacent plate and illustrated by broken lines in FIG. 1, is pivotally connected to the rear lever arm of the latter plate, and the electromagnet 18' associated with this plate and illustrated in FIG. 1 by a broken line is located, with reference to the electromagnet 18, on the other side of the pivot axis of the plate 3. The electromagnets 18 are fixed in a suitable manner in the gap between the edge rails 14, and cavities may be filled in a known manner with a paraffin wax. Cover plates 19 may upwardly close the space in which the electromagnets 18 are disposed. The rail is constructed similarly on both sides of its horizontal longitudinal center plane if the knitting machine has needle supports with jacks disposed one above the other.

The windings of the electromagnets 18 are connected to a read-out device which scans an information carrier on which information relating to the positions of the individual jacks 4 in each course are stored. When the rail 1 is displaced in opposition to the direction of the arrow 10, the upper plates 3 are displaced in a clockwise direction and the lower plates 3 are disposed in an anti-clockwise direction because the rear plate ends are pivoted towards each other by the inclined faces 12. When thereupon one of the electromagnets 18 receives a current impulse it holds the respective plate in this position when the rail 1 is moved out of the region of the inclined faces 12 in the direction of the arrow 10 towards the rear ends of the jacks 4. In this movement the plates which are not detained in the above described position by the associated electromagnets 18, are pivoted back again by the spring 9 into their starting position illustrated in FIG. 1. If this appears to be preferable, the plates may be detained in the position then assumed by a detent means (not illustrated) which engages the rear end of the plates. The forward ends of the plates pivoted back into the starting position, not, however, the plates temporarily held by the electromagnets 18, then come into abutting engagement with the rear ends of the jacks 4 and push the respective abutting jacks forward in the needle support 11 when the rail 1 is moved further in the direction of the arrow 10.

In the embodiment of the invention illustrated in FIGS. 3 and 4 a plurality of electromagnets 18 which are disposed on the same side of the vertical longitudinal center plane are grouped together to form independent insert units in cassettes 20 having a U-shaped cross-section open towards the armature rod 15; the electromagnets 18 are inserted in grooves 21 at the inner surface of the walls of the cassettes forming the limbs of the U-shaped cross-section. The cassettes 20 are l or 2 inches wide and contain, for example for a l4-gauge machine, seven or 14 electromagnets 18. Each electromagnet 18 has a winding 22 which produces the magnetic flux to the pole faces 27 and 28 when it is energized. The ends of the winding 22 are joined, such as by soldering, to connecting terminals 23 and 24, respectively, after insertion of the electromagnets into the cassette. In a further embodiment of the invention, all the connecting terminals 23 disposed in thecassette 20 are conductively conducted to each other and to a common point, such as earth, by means of a metal strip 25. The connecting terminals 24 are conductively connected to sockets 26 which are accessible from the outside, e.g., from above in the case of cassettes 20 inserted between the upper edge rails 14 in FIG. 1.

The cassettes 20 consist of a synthetic resin, for example of thermosetting or thermoplastic extrudable or hot moldable material. They do not extend over the whole width of the gap between the edge rails 14 but only half way, so that, therefore, the yokes (referred to the U-shaped cross-section) of mutually oppositely disposed cassettes rest against each other. The connecting terminals 24 do not extend to the outer surface of the cassette so that the connecting terminals of oppositely disposed cassettes cannot come into mutual conductive contact. Push connectors are inserted into the sockets 26 and the control impulses are applied thereby to the respective magnets 18. Any cavities still remaining within a cassette 20 may be filled in a known manner with a paraflin wax or any other suitable insulating substance.

Referring now to FIGS. and 6, a knitting machine (not illustrated) may have a shaft 61 which rotates once during each operating cycle of the machine and which is provided with a cam 62 arranged to actuate a switch 63 which controls by way of a lead 64 a canceling impulse transmitter 65, from which the canceling impulses are supplied to the electromagnets 138. In this case, the switch 63 and the cam 62 on the shaft 61 are arranged in such manner that the cancelling impulse transmitter 65 is triggered at the instant at which the setting impulse terminates which energizes the electromagnet 138.

A plate bed 107 extends over the whole width of the machine and plates 110 are supported thereon by a stationary bearing pin 109 permitting them pivotal movement through a limited angle. Each of the plates 110 has at its end adjacent to the jack ends 139, a striker face 111 which is intended for abutting engagement with a respective jack end 139. At their opposite ends the plates 110 which are disposed on both sides of the plane of symmetry of the plate bed 107 are provided with profiled ends 112 having inclined faces 113, 114 which cooperate with appropriate surface portions 116, 117 of a detent rail 115; the latter is guided for movement towards the ends of the plates 110 and away therefrom. The plate bed 107 together with the plates 110 is displaceable approximately in the longitudinal direction of the plates. Symmetrically disposed adjusting rails 134 are provided on both sides of the path of movement of the plate bed 107 and are rigidly attached to the machine. The adjustment rails 134 have run-up faces 135 which have an inclination of between 15 and 60 relatively to the plane of symmetry. The reciprocatory movement of the plate bed 107 extends parallel to the plane of symmetry of the plate bed. In the return movement of the plate bed 107, in which the plate bed moves away from the jack ends 139, a rounded projection 137 at each end 112 of a pair of plates 110 comes into abutment with the respective inclined face 135. During the further return movement of the plate bed 107, these projections which are disposed remote from each other and thus also the plate ends 112 are guided inwardly by the inclined faces 135, whereby the plates are pivoted about the bearing pins 109 so that the striker faces 111 move outwardly.

The adjusting rails 134 are attached to the machine frame with the run-up faces 135. In contrast thereto, the entire plate bed 107 is moved together with the electro-magnets 138 and the plates 110 in a direction corresponding approximately to the longitudinal direction of the jack ends 139. The detent rail 115 also takes part in the aforementioned motion, but also executes an additional movement. At the instant at which the projections 137 contact the faces 135, the rail 115 is moved with respect to the plate bed 107 from the position illustrated in FIG. 6 toward the right in the direction toward the U-shaped part carrying the adjusting rails 134 so that the pivotal movement of the plates 110 is not impeded by the rail 115. Only after the plate bed 107 has been moved backwards again together with its associated parts and the projections 137 have been moved out of the effective range of the faces 135, the rail 115 is shifted with respect to the plate bed 107 to such an extent that it assumes the position shown in FIG. 6, thereby effecting locking.

FIG. 11 shows the detent rail 115 in a detached position from the plates 110. When in this position the plates can pivot around the axes 109.

FIG. 12 shows the detent rail in its locking position wherein the plates are precluded from movement around the axes 109. The upper plate in FIG. 12 is locked so as not to be contacted by a jack 139 while the lower plate is locked in a working position for engagement with a jack 139.

The operation takes place in the following manner. The detent rail 115 moves rightwardly relative to the plate bed 107. Thereafter, the plate bed 107 likewise moves toward the right together with its associated parts such as the plates 110 and the electromagnets 138 in the direction toward the adjusting rails 134. The position of the detent rail 115 relative to the plate bed 107 remains constant, i.e., the rail 115 moves together with the plate bed 107. Then, the faces bring about the pivoting of the plates 110. At this point, the electromagnets 138 select specific plates in accordance with the desired pattern, and these magnets retain the associated plates. With the plates being retained, the bed 107 moves again to the left thereby maintaining the relative position with respect to the detent rail 115. Thereafter, the rail 115 is shifted relatively to the plate bed 107 into the position shown in FIG. 6. During this step, the plates 110 are either locked in the illustrated position or are locked in a somewhat displaced position wherein they contact the electromagnets 138.

My copending application Ser. No. 802,931, now US. Pat. No. 3,604,219 discloses a mechanism for translating bed 107 and rail 115 relative thereto as described herein.

Each plate 110 is associated with an electromagnet 138. All electromagnets 138 of one side of the plate bed 107 are fixed in a common rail, one such magnet rail being provided on each of the two sides of the plate bed 107. After all plates 110 have been placed against the electromagnets 138 by the inclined faces 135 during the return movement of the plate bed 107, individual electromagnets 138 are supplied by the readout device with a setting impulse in accordance with the desired pattern; they are energized thereby and thus hold the selected plates 1 10 in position. During the forward movement of the plate bed 107 towards the jack ends 139, the plates 110 which are not detained by electromagnets 138 associated therewith are pivoted back into their starting position by means of tension springs 146 one of which is always arranged between two mutually oppositely disposed plates 110; in the starting position the striker faces 111 are moved inwardly and form abutments for the jack ends 139. All the plates 110 which are detained by the electromagnets 138 are located in a position in which the striker faces 111 are pivoted out of the region of the jack ends 139. Before the striker faces 111 of the plates 110 come into abutting engagement with the jack ends 139, the detent rail 115 is moved towards the rear plate ends 112 and all plates 110 are detained in their respective position.

The plates 110 are provided at their edge turned towards the plate bed with an open slot 140 which permits them to be seated on the bearing pin 109. The plates 110 are held on the continuous bearing pin 109 by means of a rail 141 which is attached to-the rail carrying the electromagnets 138.

In the diagram illustrated polarized FIG. 7 a setting impulse 66 and a cancelling impulse 67 following thereupon are plotted against time; also shown is a detent graph 68 indicating the course of movement of the detent device and the time relationship to the pulses. The setting impulse 66 has a rectangular shape and its trailing front continues directly as the leading front of the oppositely polarised canceling impulse 67 the amplitude and duration of which is matched to suit the respective electromagnet 138. The movement of the mechanical detent means begins earlier than the trailing front of the setting impulse 66 and is completed not later than at the instant at which the setting impulse 66 terminates. The period of detention is longer than the duration of the cancelling impulse. In place of the approximately rectangular shape of the canceling impulse 67, alternatively alternating current half-waves 69 having a length of milliseconds and taken, e.g., from the mains supply, may be used for cancelling the remanent magnetism. In order to ensure that the trailing front of the setting impulse coincides in time with the start of the 10 millisecond impulse, the setting impulse may be arranged to be switched off dependently upon the mains phase position. In most cases, however, it is sufficient to use the mains half-wave following the trailing front of the setting impulse, because this time interval is always shorter than ms.

Instead of a steep rising front, the setting impulseillustrated in FIG. 9 has a rising front in the shape of a curve following an exponential law. Such curved rising front is obtained when a capacitor 71 is connected in parallel with a winding 70 of the electromagnet 138 and is charged when the direct current setting impulse is applied, thereby deforming the potential rise across the winding. The winding 70 and the capacitor 71 form an oscillatory circuit, and as soon as the setting impulse ends the capacitor 71 discharges throughthe winding 70 and produces a damped oscillation 72 which follows always immediately the trailing front of the setting impulse.

It is understood that the invention is not limited to the embodiment illustrated by way of example, but that modifications thereof are possible without the scope of the invention being exceeded. Such modifications may result in particular from the fact that in embodiments of the invention optional features are used by themselves or several thereof in any combination. In particular, in place of a direct switch control of the cancelling impulse transmitter, the impulse transmitter may be controlled by the read-out device.

What is claimed is:

l. A knitting machine comprising needles mounted in a needle support, jack means engageable with said needles, a rail member arranged to be moved periodically towards and away from said jack means, plates pivotally mounted on said rail member and provided with striker means for selective engagement with said jack means upon movement of said rail member towards said jack means for displacing selected needles, electromagnetic means mounted on said rail member, one electromagnetic means being provided for and associated with each of said plates, an armature member attached to each plate; said armature member of said plate being associated with said electromagnetic means and said rail member to form parts of an electromagnetic circuit, an information storage means, said electromagnetic means being arranged to be energized in accordance with signals derived from information stored in said information storage means thereby to effect selective pivoting of said plates into a position in which said striker means engage selected jack means, and means for de-magnetizing at least temporarily at least some of said parts forming said electromagnetic circuit, while said plates are detained in said selected position.

2. Apparatus for controlling the jacks of the needles in the needle support of a knitting machine, in particular a Jacquard machine, by means of an information carrier in which information relating to the position of the individual jacks in each course is stored, wherein the knitting machine has a rail which extends over the length of the needle support and is periodically moved against the rear end of the jacks for the purpose of adjusting the needles, and wherein displaceable strikers are provided which cooperate with the jack ends and which are disposed at one end of plates pivotally mounted on the rail, the strikers being adapted to be moved selectively into and out of engagement with the jack ends by means of electromagnets in accordance with the information stored in the information carrier, characterized in that the rail and the plates and magnetizable parts of the magnetic circuit of each of the electromagnets are arranged to be at least temporarily de-rnagnetized during the operation.

3. Apparatus for controlling the jacks of the needles in the needle support of a knitting machine, especially a Jacquard machine, by means of an information carrier in which information relating to the position of the individual jacks in each course is stored, wherein the knitting machine has a rail which extends over the length of the needle support and is periodically moved against the rear ends of the jacks for the purpose of adjusting the needles, displaceable strikers being provided for cooperation with the jack ends and disposed at one end of plates pivotally mounted'on the rail, the strikers being selectively moveable into or out of engagement with the jack ends in accordance with a pattern stored in the information carrier by means of electromagnets, wherein an armature rod of non-magnetizable work material is disposed at each plate and extends approximately at a right angle to the longitudinal axis of the plate and at a right angle to its pivot axis, which armature carries an armature disc of magnetizable material in the region of the pole faces of the associated electromagnet.

4. Apparatus according to claim 3, wherein each armature rod is displaceably guided in its axial direction and is pivotally connected to the plate at a location spaced from the pivot axis of the plate.

5. Apparatus according to claim 1, wherein the electromagnets associated with mutually adjacent plates are staggered and disposed in two rows.

6., Apparatus according to claim 1, wherein the plates are constructed as two armed levers and wherein the electromagnets of adjacent plates are disposed on different sides of the pivot axis of the plates.

7. Apparatus according to claim 3, wherein flangelike upstanding edge rails of non-magnetizable material are disposed along the edges of the rail, and guides for the armature rods are provided therein.

8. Apparatus according to claim 1, wherein a plurality of magnets are grouped together to form insert units.

9. Apparatus according to claim 7, wherein the magnets are staggered and disposed in two rows and wherein only magnets disposed in the same row are grouped together to form an insert unit.

10. Apparatus according to claim 8, wherein an insert unit is provided with a cassette which has a U- shaped cross-section and which is open towards the armature rods, the cassettes having inserted therein the magnets and being provided with connecting terminals for the winding ends of the electromagnets.

11. Apparatus according to claim 10, wherein at least the terminals of one end of the magnet windings are connected in an electrically conductive manner to terminal parts which are accessible from the outside when the respective insert unit is inserted in the rail.

12. Apparatus according to claim 1 1, wherein the external terminal parts are constructed as sockets.

13. Apparatus according to claim 1, wherein a magnetic flux is produced which is directed oppositely to the remanence of the magnetic circuit of the electromagnet, wherein a cancelling impulse transmitter is provided which is controlled in synchronism with the operating cycle of the apparatus and the output of which is connected to the electromagnets, and wherein the canceling impulse produced by the cancelling impulse transmitter has sufficient power and duration for canceling the remanent magnetism in the stationary and in the displaceable parts of the magnetic circuit of the electromagnets.

14. Apparatus according to claim 13, wherein the setting impulse terminates directly after detention of the strikers has been effected, and the canceling impulse follows directly the setting impulse while the strikers are detained.

15. Apparatus according to claim 14, wherein the detention means for the strikers is constructed so that the strikers are movable slightly in the return direction.

16. Apparatus according to claim 13 wherein the cancelling impulse with adjustable amplitude consists of at least one half-wave of the alternating mains current.

17. Apparatus according to claim 13 wherein the canceling impulse is in the form of a darnped oscillation.

18. Apparatus according to claim 17, wherein for producing the cancelling impulse a capacitor is provided which is connected in parallel with the winding of the electromagnet.

19. Apparatus according to claim 13 wherein the canceling impulse transmitter is contained in a read-out device and is controlled thereby.

Claims (19)

1. A knitting machine comprising needles mounted in a needle support, jack means engageable with said needles, a rail member arranged to be moved periodically towards and away from said jack means, plates pivotally mounted on said rail member and provided with striker means for selective engagement with said jack means upon movement of said rail member towards said jack means for displacing selected needles, electromagnetic means mounted on said rail member, one electromagnetic means being provided for and associated with each of said plates, an armature member attached to each plate; said armature member of said plate being associated with said electromagnetic means and said rail member to form parts of an electromagnetic circuit, an information storage means, said electromagnetic means being arranged to be energized in accordance with signals derived from information stored in said information storage means thereby to effect selective pivoting of said plates into a position in which said striker means engage selected jack means, and means for demagnetizing at least temporarily at least some of said parts forming said electromagnetic circuit, while said plates are detained in said selected position.

2. Apparatus for controlling the jacks of the needles in the needle support of a knitting machine, in particular a Jacquard machine, by means of an information carrier in which information relating to the position of the individual jacks in each course is stored, wherein the knitting machine has a rail which extends over the length of the needle support and is periodically moved against the rear end of the jacks for the purpose of adjusting the needles, and wherein displaceable strikers are provided which cooperate with the jack ends and which are disposed at one end of plates pivotally mounted on the rail, the strikers being adapted to be moved selectively into and out of engagement with the jack ends by means of electromagnets in accordance with the information sTored in the information carrier, characterized in that the rail and the plates and magnetizable parts of the magnetic circuit of each of the electromagnets are arranged to be at least temporarily de-magnetized during the operation.

3. Apparatus for controlling the jacks of the needles in the needle support of a knitting machine, especially a Jacquard machine, by means of an information carrier in which information relating to the position of the individual jacks in each course is stored, wherein the knitting machine has a rail which extends over the length of the needle support and is periodically moved against the rear ends of the jacks for the purpose of adjusting the needles, displaceable strikers being provided for cooperation with the jack ends and disposed at one end of plates pivotally mounted on the rail, the strikers being selectively moveable into or out of engagement with the jack ends in accordance with a pattern stored in the information carrier by means of electromagnets, wherein an armature rod of non-magnetizable work material is disposed at each plate and extends approximately at a right angle to the longitudinal axis of the plate and at a right angle to its pivot axis, which armature carries an armature disc of magnetizable material in the region of the pole faces of the associated electromagnet.

4. Apparatus according to claim 3, wherein each armature rod is displaceably guided in its axial direction and is pivotally connected to the plate at a location spaced from the pivot axis of the plate.

5. Apparatus according to claim 1, wherein the electromagnets associated with mutually adjacent plates are staggered and disposed in two rows.

6. Apparatus according to claim 1, wherein the plates are constructed as two armed levers and wherein the electromagnets of adjacent plates are disposed on different sides of the pivot axis of the plates.

7. Apparatus according to claim 3, wherein flange-like upstanding edge rails of non-magnetizable material are disposed along the edges of the rail, and guides for the armature rods are provided therein.

8. Apparatus according to claim 1, wherein a plurality of magnets are grouped together to form insert units.

9. Apparatus according to claim 7, wherein the magnets are staggered and disposed in two rows and wherein only magnets disposed in the same row are grouped together to form an insert unit.

10. Apparatus according to claim 8, wherein an insert unit is provided with a cassette which has a U-shaped cross-section and which is open towards the armature rods, the cassettes having inserted therein the magnets and being provided with connecting terminals for the winding ends of the electromagnets.

11. Apparatus according to claim 10, wherein at least the terminals of one end of the magnet windings are connected in an electrically conductive manner to terminal parts which are accessible from the outside when the respective insert unit is inserted in the rail.

12. Apparatus according to claim 11, wherein the external terminal parts are constructed as sockets.

13. Apparatus according to claim 1, wherein a magnetic flux is produced which is directed oppositely to the remanence of the magnetic circuit of the electromagnet, wherein a cancelling impulse transmitter is provided which is controlled in synchronism with the operating cycle of the apparatus and the output of which is connected to the electromagnets, and wherein the canceling impulse produced by the cancelling impulse transmitter has sufficient power and duration for canceling the remanent magnetism in the stationary and in the displaceable parts of the magnetic circuit of the electromagnets.

14. Apparatus according to claim 13, wherein the setting impulse terminates directly after detention of the strikers has been effected, and the canceling impulse follows directly the setting impulse while the strikers are detained.

15. Apparatus according to claim 14, wherein the detention means for the strikers is constructed so that the strikers aRe movable slightly in the return direction.

16. Apparatus according to claim 13 wherein the cancelling impulse with adjustable amplitude consists of at least one half-wave of the alternating mains current.

17. Apparatus according to claim 13 wherein the canceling impulse is in the form of a damped oscillation.

18. Apparatus according to claim 17, wherein for producing the cancelling impulse a capacitor is provided which is connected in parallel with the winding of the electromagnet.

19. Apparatus according to claim 13 wherein the canceling impulse transmitter is contained in a read-out device and is controlled thereby.

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