US3818728A - Control device for the needles of a knitting machine - Google Patents

Abstract

A control device for the needles of a knitting machine having a control element which, in accordance with a predetermined knitting pattern, selects the needles required for the knitting process. The needles or pushrods associated therewith are moved by a drive device, out of a rest position and into an operative position, wherein the control element has a surface which is divided up into electrically-conductive and nonconductive fields which correspond to the knitting pattern and are scanned consecutively during operation by a scanning element adapted to be moved transversely to the direction of feed of the fields. This scanning element provides an output signal of a first or a second type, depending on the character of the scanned fields. The drive device is moved past the needles or their associated pushrods synchronously with the scanning speed. In the presence of a signal of the first type, an electomagnetic setting element of the drive device is moved so that the path is free for a needle or pushrod which at this time is located in the region of the setting element so that it can move out of the rest position into the operative position.

Description

United States Patent [191 Erb [54] CONTROL DEVICE FOR THE NEEDLES or A KNITTING MACHINE [75] Inventor: Ernst Erb, Basel, Switzerland [73] Assignee: Erba Maschinenbau AG, Basle,

Switzerland 22 Filed: Nov. 30, 1972 21 Appl. No.: 310,711

[30] Foreign Application Priority Data Nov. 30, 1971 Switzerland 17397/71 [52] U.S. C1. 66/154 A, 66/75, 66/50 R [51] Int. Cl D04b 15/66 [58] Field of Search 66/75, 78, 154 A, 50

[56] References Cited UNITED STATES PATENTS 1,795,235 3/1931 Ruinnet 66/75 2,072,969 3/1937 66/154 A 2,153,342 4/1939 Ruinnet 66/75 2,157,989 5/1939 Lawson 66/75 2,173,488 9/1939 Tandler et a1. 66/75 3,247,815 4/1966 Polevitzsky... 112/79 3,292,393 12/1966 Ribler 66/154 A 3,534,566 10/1970 Farmer et a1. 66/50 3,641,788 2/1972 Mori et al. 66/75 3,722,434 3/1973 Strother et a1 112/79 June 25, 1974 Primary Examiner-Ronald Feldbaum Attorney, Agent, or FirmWenderoth, Lind & Ponack 5 7 ABSTRACT A control device for the needles of a knitting machine having a control element which, in accordance with a predetermined knitting pattern, selects the needles required for the knitting process. The needles or pushrods associated therewith are moved by a drive device, out of a rest position and into an operative position, wherein the control element has a surface which is divided up into electrically-conductive and nonconductive fields which correspond to the knitting pattern and are scanned consecutively during operation by a scanning element adapted to be moved transversely to the direction of feed of the fields. This scanning element provides an output signal of a first or a second type, depending on the character of the scanned fields. The drive device is moved past the needles or their associated pushrods synchronously with the scanning speed. In the presence of a signal of the first type, an electomagnetic setting element of the drive device is moved so that the path is free for a needle or pushrod which at this time is located in the region of the setting element so that it can move out of the rest position into the operative position.

12 Claims, 23 Drawing Figures PAIENIEDmzsxsu SHEEY 1 BF 4 PATENTED JUNZ 51974 SHEET 2 (IF 4 PATENTED JUNZS m4 SHEEI 3 OF 4 FIG. .10

FIG. 11 FIG. 12 FIG 13 CONTROL DEVICE FOR THE NEEDLES OF A KNITTING MACHINE BACKGROUND OF THE INVENTION The invention relates to knitting machines and concerns a control device for the needles of a knitting machine comprising a control element, which in accordance with a predetermined knitting pattern automatically selects the needles required for the knitting pro cess which are then moved out of a rest position into an operative position.

In the knitting of coloured patterns, that is so-called Jacquard patterns, or structured patterns with breaks, left-left effects or the like on a knitting machine, the needles required for the pattern must be pre-selected and made ready before every row is knitted in order that the selected group of needles can be brought into operation by a lock element.

In flat knitting machines it is known to effect needle pre-selection by means of so-called Jacquard cards. A Jacquard card of this kind usually consists of a strip of steel plate with punched-out perforations which correspond to the knitting pattern of a row of stitches and a separate Jacquard card is required for each row. The Jacquard cards required for the knitting of a complete knitting pattern are lined up next to one another by means of chain elements and, in operation, are individually and consecutively pressed against the ends of the pushrods arranged in line with the needles, by means of a Jacquard roller. In this arrangement only the needles whose pushrods strike against a solid part of the Jacquard card are moved into an operative position, whilst the pushrods which encounter a perforation remain, with their assigned needles, in the rest position.

Because each pressing of a Jacquard card against the pushrods can take place only at the end of the sliding movement of the lock, the slide must cover an additional distance after every row of stitches, which considerably lengthens the knitting time. A separate chain of Jacquard cards is required for each knitting pattern, this chain being of considerable length and involving substantial costs both in its production and installation.

A further disadvantage of this system consists in the fact that when the perforations are very finely spaced, pushrods frequently become locked and needles are consequently broken. It is clear that a frequent change of the knitting pattern is unprofitable on account of the expensive installation associated with the known Jacquard cards.

SUMMARY OF THE INVENTION An object of the invention is to provide a control device for the needles of a knitting machine which provides a reliable mode of operation, is suitable both for flat and for circular knitting machines, permits a rapid and inexpensive change of knitting patterns and is capable of effecting the needle selection during the operational movement of the lock.

The invention consists in a control device for the needles of a knitting machine having a control element which, in accordance with a predetermined knitting pattern, selects the needles required for the knitting process, which needles or pushrods associated therewith are then moved by a drive device, out of a rest position and into an operative position. The control element has a surface which is divided up into electricallyconductive and non-conductive fields which correspond to the knitting pattern, and are scanned consecutively during operation by a scanning element adapted to be moved transversely to the direction of feed of the fields, and which element provides an output signal of a first or a second type, in dependence upon the character of the scanned fields. The drive device is moved past the needles or their associated pushrods synchronously with the scanning speed. In the presence of a signal of the first type, an electromagnetic setting element of the drive device is moved so that the path is free for a needle or pushrod which at this time is located in the region of the setting element so that it can move out of the rest position into the operative position.

In this way the control element is mechanically separated from the setting element and the control elements required for the various knitting patterns may be produced relatively rapidly, and economically both in terms of cost and space.

Preferably the non-conductive fields are formed by a layer of a non-conductive coating on the metallically conductive surface of the control element. The control element may optionally be in the form of a cylindrical roller, an electrically-conductive loop which is conducted across a driven roller, or an electricallyconductive strip which is conducted in appropriate fashion.

When the control element is designed as a cylindrical roller, one rotation of the roller corresponds, for example, to one row of stitches of the relevant knitting pattern.

Means are provided for moving the scanning element transversely to the direction of feed of the fields by a threaded spindle, so that during the knitting operation, the rows of fields which are arranged in succession in the axial direction of the control element, are scanned consecutively.

For the synchronisation of the control element with the setting element there is provided a rack which meshes with a gear wheel which is connected to the control element.

The scanning element preferably has a punctiform scanning tip so that the fields of the control element may be extremely small. As only weak currents are used in the control arrangement a thin insulating layer can be used for the non-conductive fields.

When the control element is in the form of an electrically-conductive strip, the non-conductive control fields may be produced by printing, e.g. by the silkscreen printing method. The traced pattem can be transferred photographically, to the silk screen printing template, which involves advantages even in the case of small production series.

ln the case of control elements which are to be produced individually, the control surface is preferably completely printed with fine lines which correspond to the sub-division into control fields. Then the control surface is so plated that the lines in the finishing layer remain untouched and provide a permanent marking of the control fields. Subsequently the non-conductive control fields may be easily established manually by coating with an insulating lacquer. ln order to increase its resistance to wear, the insulating lacquer may be annealed.

A further advantage of the subsequent application of the non-conductive control fields is that the current signals of the electrically-conductive fields may be maintained for an arbitrary length of time without interruption, because the control surface is electrically conductive throughout.

By suitable electronic devices it can be provided that both the conductive and also the non-conductive control fields can produce control signals. For example the signals may pass through an amplifier which is provided with a switch-over arrangement by means of which a phase reversal of the signals can be achieved.

Due to this arrangement, in the case of a twocoloured row of stitches, only one row of control fields is required, because the conductive control fields can emit signals during one direction of movement, the phase reversed signals being used for the other direction. This arrangement also reduces the costs, because it is possible to produce signals of the same type on one path of the slide by means of the conductive fields and on the return path of the slide by the non-conductive fields. In this way it is possible to knit, e.g. a two-colour row of stitches with a single row of control fields so that the control pattern not only becomes cheaper, but also has a more natural appearance.

For multi-system knitting machines, it can be arranged for each lock to be assigned an individual control element, the control elements being characterised by different colours.

For coarse sub-divisions, the control fields can be drastically reduced in size on both sides, so that the control elements become smaller and cheaper. This provides the possibility that equal-sized control elements can be used for different pattern sub-divisions. It need only be ensured that the surface of the control element runs synchronously with the needle bed.

For the knitting of particularly broad patterns, preferably conductive and printed strips of a longer length are used. For example, loops of synthetic plastics material coated with a noble metal are particularly suitable for this purpose. The drive of these control bands takes place by means of a control roller which is provided with pins, in a guide arrangement.

In a development of the invention, the setting element takes the form of a very small, and thus very rapidly movable cover plate member which may be controlled by magnetic or electric pulses which are produced in the aforementioned amplifier which is driven by signals from the control element. This cover plate is particularly advantageous in association with a pushrod device in which the individual pushrods which are arranged in line with the needles are equipped with a pushrod foot, which, on the appearance of an appropriate control signal, is moved past the cover plate into a gap in a partition wall, and is subsequently automatically brought into the operative position. The advantage of this construction consists in the fact that the operative cover plate movement can take place in a small fraction of a second and need only cover a short distance of a fraction of a millimeter. It is thus possible to achieve very high control frequencies.

Preferably the pushrod foot of the pushrod possesses a wedge-shaped profile which is matched to a further wedge-shaped profile on the rear of the partition wall and behind the gap. In a first exemplary embodiment, the pushrod foot is loaded by a spring, and can penetrate into the gap in the partition wall when the cover plate opens the gap. In the course of the further feed movement of the pushrod, the pushrod foot slides up,

with its wedge-shaped profile, onto the matching profile of the partition wall.

In a second exemplary embodiment, pushrods which are not subjected to a spring-load can be pressed into the gap in the partition wall by a wedge-shaped cover plate. A predetermined frictional area of the pushrods prevents undesired displacements.

In another embodiment, all the pushrods are subjected to a spring load and, before the gap in the partition wall is reached, are allowed to slide up a sloping platform and then, on the opening of the gap by the electromagnetically-driven cover plate, move into the gap under spring force. Again in this embodiment, only an extremely short cover plate is necessary.

In the case of very fine sub-divisions one pushrod foot may be provided which connects two pushrods, for two needles.

In the case of flat knitting machines the control element, with the setting element may be arranged on a separately conducted auxiliary slide which is coupled with the main slide of the machine in such a manner that the control device precedes the pushrod lock. In this way it is ensured that the drive gear wheel of the control element is constantly engaged and synchronism cannot be disturbed.

In the case of multi-lock machines, each lock is provided with its own control device. In the case of circular knitting machines each lock is preliminarily assigned to a control device.

BRIEF DESCRIPTION OF THE DRAWINGS Some exemplary embodiments of the invention will now be described with reference to the drawings forming part of this Specification, in which:

FIGS. 1 and la are side and end views respectively of a control roller;

FIG. 2 shows part of a flexible control strip;

FIG. 3 is a longitudinal section through a scanning device for a control roller;

FIG. 4 is an enlarged individual view of a scanning head on a threaded spindle of the scanning device shown in FIG. 3,

FIG. 5 is a side view of the scanning head shown in FIG. 4;

FIG. 6 is an end view of a transport roller with an endless control strip;

FIG. 7 shows a transport roller with a guide device for an open control strip;

FIG. 8 is part of a plan view of a first example of a pushrod lock with spring-loaded pushrods;

FIG. 9 is a section through the line II of FIG. 8;

FIG. 10 is part of a plan view of a further embodiment of a pushrod lock with a cover-plate;

FIG. 11 is a cross-section through the pushrod lock of FIG. 10;

FIGS. 12 and 13 respectively show side and front views of a twin-pushrod;

FIGS. l4, l5 and 16 show respectively a broken-off sectional view, side view and plan view of a modified pushrod lock;

FIGS. 17 to 20 show further exemplary embodiments of pushrod feet;

FIG. 21 is a schematic illustration of the arrangement of the control element with pushrod lock on a special auxiliary slide; and

FIG. 22 is an illustration, corresponding to FIG. 21, of a double lock arrangement.

DETAILED DESCRIPTION OF THE INVENTION FIGS. 1 and la of the drawing show as a first exemplary embodiment, a roller-shaped control element 1 with an electrically conductive control surface, which is divided into conductive control fields la and nonconductive control fields lb. The non-conductive control fields 1b are provided, for example, by means of an insulating lacquer. The control fields la and lb of each row of fields which is distributed over the periphery correspond for example to one row of the knitting pattern, FIG. 2. The control element 1 is eg a casing drawn from brass, the surface of which has been electroplated. A keyway 1e is formed in the base by a punched-out section. During operation, this control element l is placed on a scanning device, shown in FIG. 3, of a knitting machine. This scanning device is pennanently secured to the knitting machine by means of a bearing block 14. The bearing block 14 carries a stationary spindle 2 with a front limiting plate 2a, which serves to locate a sintered bearing 9 which runs on the spindle. At the foot of the spindle 2, there is arranged a gear wheel 3, mounted thereabove, having teeth 3a, which mate with the teeth of a rack (not shown) which is fixed to the knitting machine. This gear wheel 3 serves to synchronise the control element 1 with a pushrod drive device which will be described later.

A roller bearing 4, which accommodates the rollershaped control element 1 is also pivotally mounted on the spindle 2 and a recess 4a in the roller bearing 4 serves to receive the keyway 1e. To provide a connection between the gear wheel 3 and the roller bearing 4 there is provided toothing 6, a coupling magnet 7 and a coupling plate 7a.

On the front sintered bearing 9 there is arranged a front centering attachment 8 for the control element 1, with a holding magnet 8a. The roller bearing 4 is produced from synthetic plastics material. The holding magnet 8a considerably simplifies the change of control elements, when knitting patterns are changed. In order to change the control element 1, as shown in FIG. 3, one merely loosens the front centering attachment 8 against the force of the holding magnet 8a, from the sintered sleeve 9 and then, with the new control element, brings it back into a force-locking connection with the sintered sleeve 9.

The coupling magnet 7 also consists of a permanent magnet body which is detachably assigned to the iron coupling plate 70.

In order to be able to consecutively scan the rows of control fields which are arranged behind one another on the control element 1 in the axial direction, the scanning device has a scanning head 10 with a fine scanning wire 10a which is displaceably mounted by means of a threaded spindle 11 in the bearing block 14, arranged parallel to the longitudinal axis of the control element 1. By a predetermined rotation of the threaded spindle II, the scanning head 10 is moved from one row of control fields to the next row of control fields. For the adjustment of the scanning head 10 relative to the control element 1, there is provided on the bearing for the threaded spindle 11, a setting knob 12 of a locking device 12a. The scanning wire 10a possesses a slight bias in the direction of the control element 1.

As shown in FIGS. 4 and 5, the scanning head 10 has a threaded slide 10b which may be brought into engagement with the threaded spindle II by means of a compression spring 100. By depressing the threaded spindle 10b, whose free end projects beyond the scanning head 10, the scanning head may be manually released from the threaded spindle and rapidly brought into the starting position. This scanning head arrangement is particularly suitable for manual knitting machines in which the selection of the control field rows is effected manually. In industrial knitting machines, on the other hand, the threaded spindle 11 is preferably moved mechanically or electromagnetically by means of a ratchet wheel which is not shown.

For the fine setting of the control element 1 on the device shown in FIG. 3, the drive gear wheel 3 is provided with numbered dividing lines and the roller bearing 4 is provided with reference lines. In order to be able to shift the pattern to any position, the toothing 6 between the gear wheel 3 and the roller bearing 4 must possess as many teeth as there are rows of control fields on the periphery of the control element.

As already described, the metallic surface of the control element is provided with control fields, in a predetermined sub-division. It is further provided that with coarser sub-divisions, the control fields can be drastically reduced in size in order to be able to produce smaller and cheaper control elements. Control elements of a given size can also serve for various subdivisions. What is important is that the drive wheel should possess the same sub-division as the machine and that the control element should possess the same number of control fields as the number of teeth on the gear wheel. In the production of the control element 1, fine lines are provided by a covering lacquer which, on a subsequent electroplating, represent breaks in the plated layer. After electroplating, the lines of covering lacquer are removed so that these zones become electrically conductive. However, a fine field marking still remains which simplifies the application of nonconductive fields lb, by hand. Alternately, it is possible to produce the conductive boundary lines by plating with a different coloured noble metal for example silver on gold or vice versa.

Manual application of the non-conductive fields lb is used only for control elements which are required in small numbers. If control elements of this kind are to be produced on a large scale, for example for use on home knitting machines, then these non-conductive fields can be printed on e.g. by means of silk screen printing in direct fashion, with the application of an insulating lacquer to the finished surface which lacquer can be subsequently annealed.

In addition to cylindrical control elements I, for example for very wide knitting patterns, strip-shaped control elements are provided, as shown in part in FIG. 2. The control element shown in FIG. 2 consists of a loop or a strip of metal or synthetic plastics material which has been electroplated with a metal. To ensure a synchronous feed, this control strip is provided with transport holes 1d, and its metallic surface is divided, as described above in the case of the control element 1, by visible and electrically conductive lines 10 into control fields 1a, in accordance with a knitting pattern, some of which may be transformed into non-conductive control fields lb by covering with a non-conductive coating. If the control element 1 shown in FIG. 6 is formed as a loop, it is transported by a transport roller 16 provided with pins 16a. in synchronism with the feed of the machine. The pins engage in the transport holes 1d of the strip-shaped control element 1, as shown in FIG. 6, and two guide rollers 17 serve to guide the strip.

Very long control elements 1 are formed, as shown in FIG. 7, as strips and are additionally conducted through a linear, double strip guide 19. Particularly wide knitting patterns may be accommodated on control elements of these two kinds as shown in FIGS. 6 and 7. The synchronisation of the transport roller 16 takes place in a similar manner as that described above with reference to FIG. 1.

Whereas FIGS. 1 to 7 relate to the embodiments of the control element and scanning device, FIGS. 8 to 18 show arrangements for the selection and the feed of the needles of the knitting machine to their operative position. All the exemplary embodiments have as a common feature, the combination of a partition wall with an inlet gap for pushrod feet, which gap is normally closed off by a coverplate and only in the presence of a specific control signal from the control element, is temporarily released to allow passage therethrough of a selected pushrod foot. As a result of a special formation of the partition wall in the region of the inlet gap and of the coverplate it is arranged that a coverplate movement of a few tenths of a millimeter is sufficient to release a selected pushrod foot.

FIGS. 8 and 9 show one embodiment of the pushrod selection arrangement, which embodiment is particularly suitable for circular knitting machines. Needles 26, associated respectively with pushrods 20 are mounted in parallel grooves of a needle bed 27 so as to be longitudinally displaceable. Each pushrod 20 is provided with a foot 20a which is wedge-shaped on both lateral sides thereof and which co-operates with a drive device including a partition wall 22, which is part of a pushrod lock of the knitting machine. During the knitting process, this partition wall 22 is moved from left to right as shown in FIG. 8 on top of the pushrod feet 20a. In the partition wall 22 there is located a gap 23 which is bounded on both sides by acute-angled dividing edges 23a, and, from one dividing edge 230 extends into a sloping wedge surface 220, which displaces the selected pushrod feet 20a upwardly so that their associated needles 26 pass into their operative position.

As shown in FIG. 9, each of the pushrods 20 is biased upwardly by a spring 21 towards its operative position. As soon as a pushrod which has been selected by the control element 1, is located, with its foot 20a in front of the gap 23, an electromagnet or other electrically operated means (not shown) and which is arranged to operate a setting element such as the coverplate 24, is fed with a current pulse which is produced by amplification of a control signal emanating from the control element 1. As the coverplate 24 is also wedge-shaped. complementarily to the wedge surface 220, a movement of a few tenths of a millimeter of cover plate 24 (to the right as viewed in FIG. 9) is sufficient to allow the sloping wedge surface of the coverplate 24 to pass beyond the dividing edge 23a in the gap 23, thus allowing the selected pushrod foot 20a to be moved upwardly into gap 23 by its associated spring 21. The selected pushrod 20 is then automatically pushed along on the wedge surface 22a, with its foot 200.

The coverplate 24 is moved by a control magnet axially to the pushrod feet, into the gap 23 to such an extent that the end of a nonselected pushrod foot is conducted from the end of the partition wall 22 by coverplate 24 across the gap 23. Due to this arrangement,

the coverplate only needs to move a small distance from the position which allows the pushrod foot to slide over the gap, and the coverplate needs to be withdrawn by only a few tenths of a millimeter, so that it is possible for the magnet to follow the high frequency of the control pulses.

The essential advantage of this construction is the high operative frequency which is obtainable due to the small coverplate movements and its co-operating wedge surface.

FIGS. 10 and 11 show another embodiment of a pushrod selection device which is particularly suitable for flat knitting machines. This embodiment differs from that described above mainly in that here the pushrods 20 are not biased in one direction by spring force, but are mounted, with a predetermined static friction, in their grooves in the needle bed 27. Thus the pushrod feet 20a do not automatically slide upwardly into the opened gap 23 in the partition wall 22, but are pushed in by a suitably-formed slide rod 25. As shown in FIG. 10, this slide rod 25 is wedge-shaped. In the rest state (moved to the right from the position shown in FIG. 11), the wedge-shaped slide rod 25 is arranged at such a distance from the region of the pushrod feet 200, that the latter will not contact slide rod 25 and still retain their rest state, i.e. they move past the gap 23. If, however, the electromagnet which operates the rod 25 is fed with a current pulse, then rod 25 is moved a small distance towards the gap 23, so that the next pushrod foot 20a to be selected slides upwards, with its wedge surface, against the complementary wedge surface of the slide rod 25, to subsequently be moved by the wedge surface 22a of the partition wall 22 towards its associated needle which it is to set in operation.

In this embodiment also, the path of the wedgeshaped slide rod 25 is so short that high operational frequencies are possible. In this embodiment the gap 23 is kept somewhat wider than the pushrod foot 20a in order that the pushrod feet can move into the gap from both sides.

For very fine pattern sub-divisions, as shown in FIGS. 12 and 13, twin pushrods are provided, which have a common foot. In this way the pushrod selection frequency may be reduced by half.

FIGS. 14 to 16 show another embodiment of pushrod selection and drive device. In an auxiliary needle bed 28 provided with channels 29 are arranged pushrods 30 which are initially stressed by means of springs 31 in the transverse direction so that they are pressed into their lower position as shown in FIG. 14. Each pushrod 30 has, at its rear end, an offset pushrod foot 32 which as a double-wedge shaped profile as shown in FIG. 15 in a rear end view of the pushrods 30.

A drive device including a flat, strip-shaped, sloping platform or wall 33, when in operation, moves from right to left under the pushrods 32, as shown in FIG. 15, and raises the pushrods against the force of springs 31. Between the end of the platform 33, which is at the rear in the direction of feed, and a sliding wedge 36 which in the end view shown in FIG. 15 is flat and in the plan view of FIG. 16 is wedge-shaped, there is arranged a gap 34, which is normally open. Pushrod feet 32 which find the gap 34 open, are pressed in by their springs 31 and remain below the sliding wedge 36, as shown in FIG. 15.

To bring a selected pushrod 30 into its operative position, a flat cover plate 35 is driven by its electromagnet (not shown) in such manner (upwardly from the position shown in FIG. 16) that it closes the gap 34. As shown in FIG. 15, this selected pushrod foot 32 then slides up to the upper edge of the sliding wedge 36, and in the continued feed movement of sliding wedge 36 with respect to the pushrods 30, this selected pushrod as shown in FIG. 16 is moved along, by means of its offset neck-piece, on the wedge surface of the wedge 36, until it has reached the operative position.

The wedge angle of the pushrod feet 32 matches a corresponding wedge angle of the platform 33 and the wedge 36 in the region of the gap 34 so that the danger of blockage is ruled out.

The described gap selection mechanism can also be applied without the use of pushrods, in which case one selection pin 41 and the associated pushrod lock is provided at each of the correspondingly lengthened needle ends.

On account of the extraordinarily small space requirement of the above-described control devices, in the case of flat knitting machines it is possible for the pattern to be carried out on the front needle bed, which entails the advantage that the pattern being knitted can be seen from the front.

The invention of course is not limited to the abovedescribed exemplary embodiment and various modifications thereof are possible. For example, the base of the control element may be a non-conductive surface, for example one consisting of synthetic plastics material upon which are subsequently applied conductive control fields which are connected e.g. by a fine line to one another and to an electric terminal.

In order to achieve in fiat machines an absolute synchronism of the control field starts with the starts of the needle divisions, when the needle lock moves to and fro, the control element, together with the pushrod lock can be arranged on an auxiliary slide which may be coupled with the main slide of the knitting machine in such a manner that the pushrod lock can precede the main lock in both directions. In this arrangement the auxiliary slide is unlatched at the end of the row, until the main lock has emerged, and turned, and then again be latched on and taken along ahead. The control element constantly remains engaged, via its gear wheel, with the rack, so that control elements with various pattern repeats can be used, where control elements in endless band form are available.

Such embodiments are schematically represented in FIGS. 21 and 22; here the main lock is marked A and indicated by a large triangle, whilst the pushrod lock is marked B and represented by a small triangle. The control element is symbolically indicated by concentric rings. In the embodiment shown in FIG. 22, a double lock is shown which can also be extended in similar manner to form a triple lock. This feature constributes substantially to the simplification of the pattern in machine knitting.

The pushrods shown in FIGS. 8 to 13 can be cast in synthetic material, but the pushrod feet 32 shown in FIGS. 14 to 16 must be milled or ground out of steelpunched pushrods.

The most important factor of the selection mechanism is however, the gap, having two acute ends facing towards it and the cover plate which penetrates into the gap in a direction parallel to the pushrod foot. This cover plate need be moved only a few tenths of a millimeter under the end of the pushrod foot 32, in order that the latter is conductive via the gap into the slide wedge 36, thus allowing the rapid selection of the pushrod feet.

FIGS. 17 to 20 show a further embodiment of the pushrod feet. Here a pushrod foot 39 or 40 is in the form of a thin, round pin, which is simple to produce and can be hardened and pressed into a bore in the pushrod. Conductive pins of this kind can also be formed by screwing or grinding. As their diameter need only amount to a few tenths of a millimeter, again a high selection frequency can be attained because only the centre of the diameter must pass behind the edge of the partition wall. The end movement of the selection process then takes place through the corresponding wedge surface.

The pushrod shown in FIG. 17, with its transverse arrangement of the pin 39 can operate in the arrangement shown in FIGS. 8 to 11, whilst the pushrod shown in FIG. 19, with a longitudinally arranged pin 40 can operate in the arrangement shown in FIGS. 14 to 16.

For the sake of simplicity, the pushrod feet 39 and 40 are preferably in the form of cylindrical pins, but they may have a different cross-section, provided that the end section thereof possesses a cylindrical crosssection.

An important feature of the control elements is that the storage of a pattern should take place by the application of non-conductive control fields on a good conductive surface. This pattern surface is then supplied from a current source and rotated and scanned with a fine scanning wire. The conductive control fields produce weak current signals, which, amplified, are fed to a control magnet of the associated needle selection device. Control elements of this kind provide the possibility of maintaining a continuous control signal from one boundary of a control field to another while the same signal is required, which reduces the operative frequency of the cover plate.

Control elements according to the invention provide a great simplification and reduction in costs in the provision of patterning in knitting machines. The life duration thereof is also very great. The scanning wire 10a is made very thin so that it rests on the control field with a very light pressure, and as the current amounts to only a few milliamperes, the depreciation of the scanning wire an the printed-on control fields is largely avoided. The weak control signals are electronically amplified and fed to the control magnet. For the purpose of cheapening the pattern, the electronic amplifier may be provided with a switch-over arrangement by which it is possible to reverse the phase of the signals. Thus in the case of two-colour patterns, on one slide movement the conductive control fields produce signals and on the return path, using the phase reversal facility, the non-conductive control fields produce signals.

I claim:

1. For use in a knitting machine including a knitting bed and a plurality of needles longitudinally movable in said knitting bed, a control device for selecting in accordance with a predetermined knitting pattern selected of said needles of said knitting machine required for knitting said predetermined pattern and for controlling movement of the thus selected needles from a rest position to an operative position, said control device comprising:

a plurality of pushrods mounted in said knitting bed to move said needles from said rest position to said operative position, each of said pushrods having extending therefrom an integral pushrod foot;

a slide mounted to move with respect to said needle bed along a path adjacent to each of said pushrods;

a drive device mounted on said slide to move said therewith, said drive device including a surface positioned in moving contact with each of said pushrod feet, said surface having a single gap therein for passage therethrough of selected of said pushrod feet, and a single electrically operated setting elementselectively movable in a direction transverse to the direction of movement of said slide from a first position toward said gap to a second position away from said gap;

a control element having a control surface with electrically-conductive and non-conductive control fields thereon, said control fields corresponding to said predetermined knitting pattern, said control element being mounted on said slide t move therewith;

gear means interconnecting said slide and said control element for angularly displacing said control element, in synchronization with the movement of said drive device, with respect to said slide by an increment of one of said control fields per movement of said drive device between adjacent of said pushrods; and scanning element means mounted on said slide to move therewith for detecting the presence of an electrically-conductive or non-conductive control field on said control element, for producing signals of a first or second type dependent on such detected presence, and for selectively moving said setting element to or from said first and second positions thereof dependent on the production of said first or second signals, respectively.

2. A control device as claimed in claim 1, wherein said control fields are arranged in parallel rows extending in the direction of angular displacement of said control element, each of said rows corresponding to a row of said predetermined knitting pattern; and further comprising a threaded spindle mounted on said slide, said scanning element means being mounted on said threaded spindle, means for selectively biasing said scanning element means into engagement with said threaded spindle, and means for rotating said threaded spindle to move said scanning element means longitudinally of said threaded spindle to selectively align said scanning element means with a predetermined of said rows of control fields.

3. A control device as claimed in claim 1, further comprising a stationary spindle attached to said slide, bearing means mounting said control element for rotation about said stationary spindle; and wherein said gear means comprises a gear wheel mounted on said spindle and having teeth on the periphery thereof for engagement with a rack on said knitting machine, interengaging teeth on said bearing means and said gear wheel, whereby rotation of said gear wheel is imparted to said bearing means and said control element.

4. A control device as claimed in claim 3, further comprising a coupling magnet and coupling plate coupling said bearing means and said gear wheel for selective disengagement of said bearing means.

5. A control device as claimed in claim 1, wherein said movable drive device includes a wall having said single gap therein, the edge of said wall on at least one side of said gap being inclined at an acute angle upwardly and away from said gap, each of said pushrod feet having lateral edges inclined at angles equal to the actue angle of said edge of said wall, and said setting element having opposite lateral edges inclined at angles equal to the acute angle of said edge of said wall.

6. A control device as claimed in claim 5, further comprising springs biasing each of said pushrods upwardly to move the respective needles thereof into said operative position, said setting element when in the first position thereof preventing movement of a pushrod foot under the bias of the respective spring thereof through said gap, and said setting element when in the second position thereof allowing movement of a pushrod foot under the bias of the respective spring thereof through said gap into said operative position.

7. A control device as claimed in claim 5, wherein said setting element when in the first position thereof causes contact between one of the inclined lateral edges thereof and one of the lateral edges of a pushrod foot, thus pushing said pushrod foot into said gap and into contact with said inclined edge of said wall.

8. A control device as claimed in claim 5, further comprising spring means biasing each of said pushrods into said rest position, said setting element when in the first position thereof preventing movement of a pushrod foot under the bias of the respective spring means thereof through said gap, and said setting element when in the second position thereof allowing movement of a pushrod foot under the bias of the respective spring means thereof through said gap into said rest position.

9. A control device as claimed in claim 1, wherein said control element comprises an electricallyconductive surface, electroplated fine lines dividing said surface into equally sized control fields, and insulating lacquer covering those control fields constituting said non-conductive control fields.

10. A control device as claimed in claim 1, wherein said control element comprises a cylindrical roller.

11. A control device as claimed in claim 1, wherein said control element comprises an electricallyconductive loop.

12. A control device as claimed in claim 1, wherein said control element comprises an elongated electrically-conductive strip.

Claims (12)

1. For use in a knitting machine including a knitting bed and a plurality of needles longitudinally movable in said knitting bed, a control device for selecting in accordance with a predetermined knitting pattern selected of said needles of said knitting machine required for knitting said predetermined pattern and for controlling movement of the thus selected needles from a rest position to an operative position, said control deVice comprising: a plurality of pushrods mounted in said knitting bed to move said needles from said rest position to said operative position, each of said pushrods having extending therefrom an integral pushrod foot; a slide mounted to move with respect to said needle bed along a path adjacent to each of said pushrods; a drive device mounted on said slide to move said therewith, said drive device including a surface positioned in moving contact with each of said pushrod feet, said surface having a single gap therein for passage therethrough of selected of said pushrod feet, and a single electrically operated setting element selectively movable in a direction transverse to the direction of movement of said slide from a first position toward said gap to a second position away from said gap; a control element having a control surface with electricallyconductive and non-conductive control fields thereon, said control fields corresponding to said predetermined knitting pattern, said control element being mounted on said slide to move therewith; gear means interconnecting said slide and said control element for angularly displacing said control element, in synchronization with the movement of said drive device, with respect to said slide by an increment of one of said control fields per movement of said drive device between adjacent of said pushrods; and a scanning element means mounted on said slide to move therewith for detecting the presence of an electrically-conductive or non-conductive control field on said control element, for producing signals of a first or second type dependent on such detected presence, and for selectively moving said setting element to or from said first and second positions thereof dependent on the production of said first or second signals, respectively.

2. A control device as claimed in claim 1, wherein said control fields are arranged in parallel rows extending in the direction of angular displacement of said control element, each of said rows corresponding to a row of said predetermined knitting pattern; and further comprising a threaded spindle mounted on said slide, said scanning element means being mounted on said threaded spindle, means for selectively biasing said scanning element means into engagement with said threaded spindle, and means for rotating said threaded spindle to move said scanning element means longitudinally of said threaded spindle to selectively align said scanning element means with a predetermined of said rows of control fields.

3. A control device as claimed in claim 1, further comprising a stationary spindle attached to said slide, bearing means mounting said control element for rotation about said stationary spindle; and wherein said gear means comprises a gear wheel mounted on said spindle and having teeth on the periphery thereof for engagement with a rack on said knitting machine, interengaging teeth on said bearing means and said gear wheel, whereby rotation of said gear wheel is imparted to said bearing means and said control element.

4. A control device as claimed in claim 3, further comprising a coupling magnet and coupling plate coupling said bearing means and said gear wheel for selective disengagement of said bearing means.

5. A control device as claimed in claim 1, wherein said movable drive device includes a wall having said single gap therein, the edge of said wall on at least one side of said gap being inclined at an acute angle upwardly and away from said gap, each of said pushrod feet having lateral edges inclined at angles equal to the actue angle of said edge of said wall, and said setting element having opposite lateral edges inclined at angles equal to the acute angle of said edge of said wall.

6. A control device as claimed in claim 5, further comprising springs biasing each of said pushrods upwardly to move the respective needles thereof into said operative position, said setting element when in the first position thereof preventing movement of a pushrod foot under the bias of the respective spring thereof through said gap, and said setting element when in the second position thereof allowing movement of a pushrod foot under the bias of the respective spring thereof through said gap into said operative position.

7. A control device as claimed in claim 5, wherein said setting element when in the first position thereof causes contact between one of the inclined lateral edges thereof and one of the lateral edges of a pushrod foot, thus pushing said pushrod foot into said gap and into contact with said inclined edge of said wall.

8. A control device as claimed in claim 5, further comprising spring means biasing each of said pushrods into said rest position, said setting element when in the first position thereof preventing movement of a pushrod foot under the bias of the respective spring means thereof through said gap, and said setting element when in the second position thereof allowing movement of a pushrod foot under the bias of the respective spring means thereof through said gap into said rest position.

9. A control device as claimed in claim 1, wherein said control element comprises an electrically-conductive surface, electroplated fine lines dividing said surface into equally sized control fields, and insulating lacquer covering those control fields constituting said non-conductive control fields.

10. A control device as claimed in claim 1, wherein said control element comprises a cylindrical roller.

11. A control device as claimed in claim 1, wherein said control element comprises an electrically-conductive loop.

12. A control device as claimed in claim 1, wherein said control element comprises an elongated electrically-conductive strip.

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