US3793850A - Patterning system for a multi-feed circular knitting machine - Google Patents

Abstract

A multi-feed circular knitting machine equipped with needles selectively raised to different heights by jacks having patterning butts arranged to be acted upon by air-operated selector cams. The latter are in pairs stacked into housings, one in advance of each feed. The two cams of each pair are for raising needles, via jacks, to tucking and clearing heights respectively. To each stack of selector cams there is a block of fluidic elements with sensing orifices in alignment with channels of information carried by a punched tape or an apertured drum driven in time with the machine. The selector cams are pushed forward by low pressure air and retracted by induced vacuum. The jacks are in a cylinder larger than a cylinder accommodating the needles, movement transmitting and amplifying levers being provided between the two whereby short movements of the jacks are converted into longer movements of the needles.

Description

United States Patent [191 Wills-Moren et al.

[ PATTERNING SYSTEM FOR A MULTI-FEED CIRCULAR KNITTING MACHINE [75] Inventors: William James Wills-Moren,

Stevington; Walter Goadby, Evington, both of England [73] Assignee: Camber International (England) Limited, Leicester, England [22] Filed: July 6, 1971 .1 1 RRl-hN9-Fl l i s c [30] Foreign Application Priority Data 7, Jil 2 21922199 1 Britain [52] US. Cl 66/50 R [51] Int. Cl D041) 15/68 [58] Field of Search... 66/50 R, 50 A, 50 B, 25, 40,

66/42, 36 A, 36 B, 8, 154 A; l37/8l.5

[56] References Cited UNITED STATES PATENTS 3,270,960 9/1966 Phillips l37/8l.5 UX

3,274,800 9/1966 Mishcon et a1. 66/50 A 3,586,061 6/1971 Lauritsen 66/154 A 3,587,251 6/1971 Vincoli 66/8 3,664,383 5/1972 Minchey et al. 66/154 A X 3,683,644 8/1972 Chvala et al 66/8 FOREIGN PATENTS OR APPLICATIONS 1,287,447 2/1962 France 66/8 1,930,522 l/l970 Germany 66/154 A 2,031,089 l/l97l Germany 66/8 892,332 3/1962 Great Britain 66/154 A Feb. 26, 1974 1,193,118 5/1970 Great Britain 66/50 R 522,556 4/1955 Italy 66/50 R OTHER PUBLICATIONS Fluidics; New Knitting Technology, The Hosiery Trade Journal, Vol. 78, N0. 930, June 1971, pp. 138 & 139.

Primary Examiner-Wm. Carter Reynolds Attorney, Agent, or FirmLarson, Taylor and Hinds 5 7] ABSTRACT A multi-feed circular knitting machine equipped with needles selectively raised to different heights by jacks having patterning butts arranged to be acted upon by air-operated selector cams. The latter are in pairs stacked into housings, one in advance of each feed. The two cams of each pair are for raising needles, via jacks, to tucking and clearing heights respectively. To each stack of selector cams there is a block of fluidic elements with sensing orifices in alignment with channels of information carried by a punched tape or an apertured drum driven in time with the machine. The selector cams are pushed forward by low pressure air and retracted by induced vacuum. The jacks are in a cylinder larger than a cylinder accommodating the needles, movement transmitting and amplifying levers being provided between the two whereby short movements of the jacks are converted into longer movements of the needles.

5 Claims, 9 Drawing Figures PATENTED FEB26 I974 sum 1 BF 6 PATENTED FEB26 I974 SHEEI 2 0F 6 PATENTEI] FEBZB I974 SHEET 6 BF 6 PATTERNING SYSTEM FOR A MULTI-FEED CIRCULAR KNITTING MACHINE This invention relates to a patterning system for a multi-feed circular knitting machine, and has reference particularly to such a system of the kind comprising, in combination, groups of individually movable selector cam members, one group in advance of each feed, arranged around the knitting head of the machine, individually operable instruments accommodated in tricks of an axially tricked cylinder co-axial with respect to the knitting machine head, said instruments being furnished with patterning butts, one patterning butt per instrument, so disposed in a multiplicity of superimposed planes as to enable them to be operated upon by the selector cam members to effect selective actuation of the instruments, and, for each group of selector cam members, programmed control means functioning at a speed related to that of the machine for selectively operating the said cam members in advance of the relevant feed in accordance with predetermined patterning requirements.

Although there is no limitation in this respect, it is principally the intention that the patterning system of this invention shall be for the selective actuation, under control, of individually operable knitting needles whereby the latter are caused either to knit or to tuck or to non-knit, according to patterning requirements. In this regard, the aforementioned instruments, broadly considered, may be the knitting needles themselves. More usually, however, the butted instruments will be in the nature of needle-actuators, such as jacks or sliders, entirely separate from the needles and, for this reason and where the context so admits, will hereinafter for convenience be referred to as pattern instruments."

Moreover, it is primarily the intention to apply the invention to a circular multi-feed knitting machine of the rotary needle cylinder type, in which instance the individually operable needles and their actuating pattern instruments move round with the knitting head, whereas the groups of selector cam members and the programmed control means for selectively operating the same are associated or combined with the stationary cam box or shell surrounding the rotary needle cylinder, or superimposed needle cylinders, as the case may be.

It would, however, alternatively be possible to apply the invention to a multi-feed machine of the stationary needle cylinder type, in which case the groups of selector cam members and the programmed control means therefor would be required to revolve together with the annular cam box or shell.

Whilst the invention is applicable to multi-feed double cylinder machines and machines of the cylinder and dial type, it is expected that the principle field of application will be to multi-colour Jacquard single cylinder body machines having cylinders of comparatively large diameter and relatively large numbers of feeds.

As to the disposition of the pattern instrument patterning butts in a multiplicity of superimposed planes as aforesaid, this will usually be such as to enable the patterning butts in any one horizontal plane to be well spaced apart circumferentially; in such an arrangement, the butts on successive pattern instruments are so relatively offset laterally in the superimposed planes as to form right around the machine circumferentially spaced inclined, i.e., diagonal, lines of butts, the lateral offsetting corresponding, of course, with the pitch of the pattern instruments circumferentially of the machine. But it is considered that other dispositions of pattern instrument butts may be adopted within the broad scope of the invention.

The invention may most advantageously be applied to the particular arrangement of pattern jacks in which these jacks are accommodated in tricks formed in a separate jack cylinder which is co-axial with, but of a larger diameter than the needle cylinder, the butts on the jacks being set out in circumferentially spaced inclined or diagonal lines (hereinafter more fully described) but with the vertical pitch of said butts reduced to such an extent that lifting movements imparted to the pattern jacks by action upon their butts of jack selector cams are less than sufficient to raise the corresponding needles to the heights required. The particular arrangement just described thus essentially also includes the provision, between the pattern jacks in the separate cylinder and the corresponding needles in the needle cylinder, of means of any suitable character, e.g., levers, for transmitting to the needles and simultaneously amplifying the lifting movements imparted to the jacks by the selector cams.

A patterning system of the kind herein referred to applied to a multi-feed circular knitting machine has heretofore often been wholly mechanical. Whilst such a mechanical system enables a wide range of patterns to be produced consistent with a reasonable system cost, its physical space limitations restrict the number of yarn feeds possible and the amount of data that can be contained in the control or programme media or component. This restricts both the rate of output of knitted fabric and the possible pattern area before repeats of pattern are necessary. In order to overcome these limitations, systems have previously been developed using programme media other than mechanical. One example is by use of a programme stored on a film which is read by photoelectric means. The electrical pulses are then used to influence the needle operation by the use of a solenoid for each needle. Such an electro-magnetic system overcomes most of the technical limitations imposed by the mechanical system but is expensive and very complex. Data must be read at a high rate, this again limiting the number of yarn feeds and output rate but allowing the much more comprehensive pattern area than a mechanical system.

The object of the present invention is to provide, in a multi-feed circular knitting machine, a generally improved patterning system of the kind concerned designed not only to increase the patterning potential, but also to permit as many feeds as possible to be incorporated in the machine, thus maintaining a high output rate of patterned knitted fabric, without either necessitating complex data preparation or incurring prohibitive cost.

The improved patterning system according to this in- In accordance with an important aspect of the invention, there is preferably provided a separate predeterminedly apertured and movable programming element or component and means for reading the same at each selector station. Such a unitary, self-contained system for each feed makes possible extensive patterning potential coupled with high output rates. In this connection it has to be realised that the rate at which information must be read and transmitted to the selector cam members would usually be too great for a central data element or component reading device to be employed. It is considered that development of such a centralised control system although not altogether excluded from the scope of this invention, would probably incur a prohibitively high development cost, with the risk that the resulting equipment, even though technically successful, would be too expensive for the market to accept.

In any event, there are in the preferred embodiment of the invention, provided in each separate programming element or component as many channels of information, i.e., lines of holes predeterminedly interspersed with un-apertured portions, as there are selector cam members in the group at each selector station: this enables relatively low reading speeds to be adopted.

The controlled air pressure system at each selector station may be wholly pneumatic in character, in which instance the movable apertured programming media or component ma itself constitute valve means to control the admission of pressurised air into or the cutting off of such air from conduits in line with the selector cam members of the relevant group. Alternatively, in a pneumatic system, the apertured programming media or components may be used to influence air valves of the diaphragm or any equivalent type.

It is, however, considered that the most suitable air pressure system fot the intended purpose may prove to be a truly fluidic one in which there are no moving parts; in such a system, a continuously flowing stream of main pressure air, confined within a conduit, would either be allowed to flow idly past a selector cam member or be diverted for rendering the said member operative by a fluidic switch or an amplifier responsive to a subsidiary low pressure air jet in turn controlled by the presence or absence of a hole in the apertured programming element or component. In other words, the presence of a hole enables a signal, in the nature of an emission, i.e., puff, of low pressure air, to pass to a fluidic switch or an amplifier the output from which operates the selector cam member.

Accordingly, the expression air pressure system herein used is intended to be a generic one sufficiently wide to cover any of the foregoing arrangements.

But whatever the precise nature of the air pressure system adopted, a selector cam member may be acted upon by air under pressure either directly or through the medium of a piston or a plunger movable axially within the relevant air conduit. Return of a selector cam member to its inoperative position, preparatory to re-selection after having been operated, may be effected either by fluidic, pneumatic or mechanical means. As examples of mechanical means may be mentioned, firstly, a spring, e.g., of the leaf type, and, secondly, a cam-like protuberance on the needle cylinder designed to push back the selector cam member as a consequence of rotation of the knitting head.

The selector cam members at each selector station may consist either of fulcrummed levers or of rectilinearly movable slides. In either event, the said members may advantageously be banked one above another in a suitable housing located at the selector station, the operative portions of the members being in the nature of inclined cams.

It has previously been stated that the knitting needles are caused either to knit, or to tuck or to non-knit, according to patterning requirements. In this regard, the projection of a selector cam member into its operative position by air pressure may serve, either directly, or through the medium of pattern instruments (with or without associated lift-amplifying means) to raise relevant needles either to clearing height or tucking height so that these needles will either knit or tuck respectively. In such a case, any needles not so raised will non-knit. Broadly considered, however, the arrangement could be reversed so that whilst all needles will normally either knit or some knit and others tuck, only those needles which fail to be raised, by selective retraction of previously operative cam members, will be caused to non-knit.

In order that the invention may be more clearly understood and readily carried into practical effect, specific embodiments thereof will now be described with reference to the accompanying drawings, wherein,

FIG. 1 is a vertical sectional view taken through the knitting head of a circular multi-feed knitting machine of the rotary needle cylinder type, this figure showing a pattern jack in a separate jack cylinder; a lever transmitting to the corresponding needle and amplifying the lifting movement imparted to the said jack by selector cam slides; a bank of fluidic elements with their respective selector cam slides at a selector station; and an apertured programming element in the form of a punched tape,

FIG. 1A is a detail vertical sectional view showing more clearly one of the pattern jacks,

FIG. 1B is a fragmentary portion of FIG. 1 drawn to a larger scale,

FIG. 2 is a detail perspective view showing a pair of the selector cam slides, a succession of the pattern jacks, and two of the needles and of the corresponding intermediate movement transmitting and amplifying levers,

FIG. 3 is a detail inner end view, as seen when looking outwardly from the centre line of the knitting head, of a few of a bank of fluidic elements together with their selector cam slides, and illustrates how these slides elevate jacks to different positions heightwise,

FIG. 4 is a plan view looking down on a few of the banks of fluidic elements and the corresponding control tapes,

FIG. 5 is a developed layout showing, in purely diagrammatic fashion, a few of the inclined or diagonal lines of patterning butts on pattern jacks, pairs of selector cam slides included in the banks at two selector stations and fragmentary portions of pattern jacks,

FIG. 6 is a part-sectional plan view of one of the fluidic elements per se, shown in relation to the punched control tape at the relevant selector station, the selector cam slide of the said element being depicted in its inwardly projected operative position, and

FIG. 7 is a view similar to FIG. 6 but showing the same selector cam slide retracted outwardly to its inoperative position.

Like parts are designated by similar reference characters throughout the drawings.

Referring to FIG. 1, it will be seen that the illustrated multi-feed circular knitting machine includes a rotary needle cylinder which is peripherally tricked at 10a to receive individually slidable knitting needles 11 of the pivoted latch type. Each needle has an operating butt 11a. The machine is also furnished, for cooperation with the needles, with outside holding-down sinkers such as 12 which are radially slidable in a horizontally disposed sinker bed 13 and are operated by cams mounted in a sinker cam cap 14.

For selectively raising the needles 11 there is provided a corresponding circular series of pattern jacks such as that indicated at 15 in FIG. 1A one to each needle. These jacks are accommodated in tricks 16a formed in a separate jack cylinder 16 which is co-axial with, but of a larger diameter than the needle cylinder 10. At its lower end the needle cylinder 10 seats within a recess 17a formed in the top of a ring 17 which in turn fits within, and sits upon an internal shoulder 16b formed on, the jack cylinder 16. The needle cylinder 10 is firmly attached to the ring 17 and the latter is secured to the jack cylinder. The lower end of this jack cylinder has bolted to it the conventional cylinder driving gear 18. Accordingly, when the gear 18 is driven from the drive source customary in such a machine, the needle cylinder 10 and the jack cylinder 16 will rotate together at the same speed.

Although the size of the machine, the number of feeds with which it is equipped and the rotational speed of the knitting head may vary widely, the particular machine now being described is assumed to have the following specification:

Needles per inch28 Needle cylinder diameter-26 inches Cylinder speedup to 20 rpm.max.

Number of feeds-78 A 30 inch machine having ninety feeds is a practical proposition commercially.

It is convenient here to mention that in FIG. 1 the jack trick 16a is shown as being empty so that the form of the trick can be fully seen: for this reason the pattern jack 15 in the next trick is for the most part hidden in FIG. 1 by the relevant trick wall. But in FIG. 1A a pattern jack 15 is fully shown.

As will be seen, the stem of each pattern jack 15 is furnished with only one patterning butt 15a; at its lower end each such jack is provided with a butt 15b arranged to be acted upon by cams such as 19 by means of which jacks, after being raised, are restored to their original positions for re selection. The upper end of each pattern jack is increased somewhat in width, from its back edge to its front edge, to provide an abutment 150 having a rounded, i.e., semicircular, upper extremity for a purpose hereinafter to be described. The single patterning butts 15a on the pattern jacks 15 are provided at different points along their straight stems so that these butts are disposed in a multiplicity of superimposed horizontal planes. The particular disposition of the illustrated butts is such as to enable the patterning butts 15a in any one such plane to be well spaced apart circumferentially. That is to say, the butts 15a on successive pattern jacks 15 are so relatively offset laterally in the superimposed planes as to present right around the jack cylinder 16 circumferentially spaced inclined, i.e., diagonal, lines of butts, the lateral offsetting corresponding, of course, with the pitch of the pattern jacks circumferentially of the machine. One such inclined line of patterning butts is clearly shown in FIG. 2. Moreover, three complete inclined lines L2, L3 and L4 of patterning butts 15a and a part of such a line L] are also depicted in FIG. 5. The pitch P of these inclined lines corresponds with a circumferential distance sufficient to accommodate a succession of 36 of the pattern jacks 15. Thus, in each inclined line there are 36 patterning butts 15a. The direction of cylinder rotation is indicated by the horizontal arrow at the bottom of FIG. 5. Assuming the patterning butts in each line to be differentiated by virtue of being lettered downwards in the sequence A, B, C, D-, these letters designating the superimposed planes, then the pattern jack 15 at the right-hand side of FIG. 5 is shown as having a butt in the top plane A, whereas the jack 15 has a butt in the plane R.

Preferably, the vertical pitch of the patterning butts 15a on successive pattern jacks 15 is such that the lower edge of the butt on any one jack is spaced vertically from the corresponding edge of the butt on the next jack a distance equal only to the overall vertical dimension of a single butt. In this preferred case, therefore, an individual selected jack can only be lifted a distance equivalent to the vertical pitch of the butts.

Advantageously, the patterning butts 15a may, as shown, be of saw-tooth form, having horizontal lower edges and upper edges which incline downwardly and outwardly from the stems of the jacks 15. By virtue of this particular shaping of the butts, inner operative cam portions of selector cam slides (hereinafter to be described) are enabled to be inserted beneath the horizontal lower edges of butts and well into the spaces between butts.

Since each pattern jack 15 is arranged to be lifted only minimal vertical distances, there must, as previously mentioned herein, be provision between the jacks in the separate cylinder 16 and the corresponding needles l 1 in the needle cylinder 10 of means for transmitting to the needles and simultaneously amplifying the lifting movements imparted to the jacks by the aforementioned selector cam slides. Conveniently for this purpose there are provided, as shown in FIGS. 1 and 2, simple, radially extending movement-transmitting and amplifying levers 20 between the upper ends of the pattern jacks l5 and the lower ends of the needles 11. These levers 20 thus extend across the annular space S between the two co-axial cylinders 10 and 16 of respectively different diameters and are located beneath the customary annular cam box or shell (not shown) surrounding the needle cylinder 10. The outer end of each of the movement-transmitting and amplifying levers 20 is formed with a near-circular fulcrum 20a which is seated in a suitably formed ring 21 combined with the upper end of the pattern jack cylinder 16. To enable them to avoid interference with the jack cylinder 16, the pivoted levers 20 may, as shown in FIGS. 1 and 1A, be of upwardly arched form. In any event, the semicircular upper extremities of the aforementioned abutments 15c of the pattern jacks 15 act upon the lower edges of the levers 20 at carefully predetermined points fairly close to the near-circular fulcrum 20a so that comparatively small lifting movements of the jacks l5 imparted by the jack selector slides now tobe described are magnified into substantially greater heightwise movements of the inner ends of the said levers.

These ends are forked as indicated at 20b to embrace and act upon outwardly directed butts 11b at the lower extremities of the needles 11.

The jack selector slides at each selector station SS are arranged in a vertical bank of superimposed pairs. The selector slides of each pair are hereinafter for convenience designated 22A and 22B. There are, of course, as many selector stations SS around the knitting head of the machine as there are feeds. Only two of these stations are diagrammatically illustrated in FIG. 5. The idea is that the operative cam portion of one of the slides, say the slide 22A of each pair shall have an outwardly directed cam face 23 adapted, by engagement with butts 15a, to lift relevant pattern jacks 15 sufficiently to cause corresponding needles 11, through the medium of the movement-transmitting and amplifying levers 20, to be raised to tucking height, whereas the operative cam portion of the companion slide 22B of the pair shall have an upwardly directed cam face 24 which, together with the cam face 23 of the slide 22A, lifts pattern jacks 15 to an extent sufficiently far to cause corresponding needles to be raised to clearing height. The cam faces 23 and 24 are gently inclined at less than to the horizontal. The butt ends of the slides 22A and 22B are, in effect, similar to pistons of air cylinders, In FIG. 3 (as seen looking outwardly from the centre line of the machine), the normal run height of a patterning butt 15a is indicated at RH. A butt 15a is lifted to height TH by a cam face 23 to position the corresponding needle at tucking height, whereas such a butt is lifted to height CH to position the relevant needle at clearing height preparatory to knitting. In FIG. 1, the pattern jack is raised only sufficiently to position the corresponding needle at tuck height, the slide 22B being shown in its retracted position. In FIG. 2, on the other hand, both of the slides 22A and 228 shown are operative, their combined upwardly directed cam faces 23 and 24 having just acted upon the patterning butt 15a of the slightly raised pattern jack 15 to position the right-hand needle 11 at clearing height. The left-hand needle in this figure is shown down in its non-knit position.

Of each such pair of jack selector slides, the slide 22A is longitudinally moved radially inwards into its operative position, independently of the slide 223 which latter remains stationary. On the other hand, whenever the slide 22B of the pair is moved radially inwards, the slide 22A is also caused to move forwardly together therewith. Each slide is arranged to traverse a distance of only 0.1 inch in a radial direction to the machine cylinder.

In the preferred example illustrated in FIGS. 1 7, the major portions of the slides 22A and 22B are disposed in superimposed horizontal planes, only the operative cam portions of the said slides having faces appropriately inclined to the horizontal. In this preferred arrangement, whenever the slide 228 of a pair is selectively moved into its operative position, the companion slide 22A is as a matter of course, also similarly moved into its operative position.

Alternatively, the selector cam slides in each vertical bank may themselves be in parallel inclined planes with respect to the horizontal so that their operative portions can be in these same planes, the angle of inclination being such as to impart to the jacks 15 the required extents of lift, all as will be hereinafter more fully described with reference to FIGS. 8 and 9.

Each of the selector cam slides 22A and 22B is operable by air pressure, and the air pressure system employed includes fluidic elements 25 each consisting of a single laminate section having an accurately produced cavity to receive one of the said slides. Seventy two of these fluidic elements 25 are stacked one above the other to form a vertical block 26 at each selecting station SS.

Each block 26 is supported upon an upstanding inner portion 270 of a fixed annular plate 27 which latter is located near to the lower end of the jack cylinder 16 and is in turn secured upon the fixed bed plate 28 of the machine. The seventy two fluidic elements 25 of each stack are clamped together between upper and lower plates 29 and 30 respectively, long screws, rivets or the like such as 31 being used to produce the clamping effect. The fluidic elements 25 are only 0.75 in. thick, the whole block 26 measuring only 5.40 in. in height. This allows the jack cylinder 16 to be of a reasonable height.

As shown in FIGS. 6 and 7, each fluidic element has a sensing orifice 32 in alignment with a channel or line of holes 33 punched in a programming element in the form of a punched tape PT. The orifice 32 extends along the median line of the fluidic element. This tape is adapted to be driven at a linear speed corresponding with the rotational speed of the knitting head of the machine, i.e., of the two co-axial cylinders 10 and 16. The tape PT, moreover, passes around a vertical tape guide 34 which, as shown in FIGS. 6 and 7, has a mainly convex front face 34a with a flat 34b thereon, a vertical exhaust duct 35 extending therethrough to practically the full height thereof and a vertical series of as many air exhaust slots 36 as there are selector cam slides 22A and 22B in the corresponding bank. Thus, the air exhaust slots 36, of which there are 72, are disposed one above the other, each of them communicating, on the one hand, with the interior of the vertical exhaust duct 35 common to them all and, on the other hand, with the small vertical space 37 provided between the aforementioned flat 34b and the opposed back of the tape. In the upstanding portion 27a of the fixed annular plate 27 is formed an annular air chamber 38 which is adapted to be continuously supplied with compressed air at low pressure. Such air may be supplied from a low pressure, high volume turbo-blower which is mounted on the machine. Extending upwardly from the top of the air chamber 38 are air feed channels 39 one per stack of fluidic elements 25. Each such air feed channel 39 leads upwardly into the lower end of a vertical air tube 40. This tube 40 extends upwardly through all of the superimposed fluidic elements 25 and has formed in its wall a vertical series of as many air feed holes 41 as there are selector cam slides 22A and 22B in the corresponding bank. The air feed holes 41, disposed one above another, are in alignment both with the respective sensing orifices 32 and also the corresponding air exhaust slots 36 in the tape guide 34. The inner end of each orifice 32 communicates with an annular channel 42 formed in the relevant fluidic element 25. This channel extends partially around the adjacent portion of the vertical air tube 40 and freely communicates with the rear or back edge of the particular selector cam slide carried by the relevant fluidic element 25. The upper end of each exhaust duct 35 is aligned with a hole 43 (open to atmosphere) provided in a plate 44 constituting a part of a punched tape cassette 45. At 46 is represented a base plate of a cassette for, say, six tapes for controlling needle selection at six feeds of the machine.

Presence of a hole 33 in the appropriate channel or line of a punched tape PT causes the relevant selector cam slide to retract in the direction of the arrow in FIG. 7, whereas no hole causes the same slide to advance in the direction of the arrow in FIG. 6. The relative sizes of orifice 32 and hole 33, and the pitch between holes 33, are arranged so that a continuous row of holes 33 is read as a continuous hole so that the selector cam slide remains retracted. Obviously, a length of tape without holes will cause the slide to remain advanced. The space 37 between the flat 34b on the front face of the tape guide 34 and the opposed back of a punched tape PT, which space is segment-shaped in crosssectional plan (see FIGS. 6 and 7), ensures that a hole 33 in the travelling tape remains in communication with the vertical exhaust duct 35, via the relevant air exhaust slot 36, for a sufficient length of time to enable retraction of the corresponding selector cam slide to fully take place as and when the said hole 33 registers with the corresponding orifice 32.

Thus, the illustrated air pressure system is such that whenever a hole 33 in a punched tape PT is in such a position as to allow air to escape to atmosphere through an air exhaust slot 36, the common exhaust duct 35 and the hole 43 at the upper end of the latter, the pressure in the channel 42 between the air feed hole 41 and the back of the relevant selector cam slide falls below atmospheric due to the Venturi effect. The result is that the slide is drawn inwards into its retracted, i.e., inoperative position as shown in FIG. 7. But as soon as the punched hole 33 passes, so that an unapertured portion of the tape is then blocking the orifice 32, the pressure of the air issuing through the relevant air feed hole 41 and passing into the annular channel 42 thereupon builds up above atmospheric and the selector cam slide is advanced into its operative position as shown in FIG. 6.

A single hole 33 in, and an un-apertured blank portion of, a tape causes a tuck selection slide 22A to move forward. No holes cause both slides 22A and 22B to move forward to raise the corresponding needles to clearing height. A double hole in the tape causes both slides of a pair to be retracted so that needles miss.

It will accordingly be appreciated that each selector station has its own punched tape PT, the latter, as shown in FIG. 4, being in the form of an endless loop.

If required, each tape loop can be punched with a different pattern of punched holes. It will accordingly be readily appreciated that a pattern could, if required to do so, extend the full width of the fabric. As previously mentioned, there is in each punched tape PT a separate channel or line of holes 33 for each fluidic element 25 in the corresponding stack. The pitch of the holes 33 along the length of a tape is, in the specific example now being described, .0935 in. Since the machine is equipped with 2,304 needles, there are 64 hole positions per revolution of the cylinders and '16, i.e., per 5.984 in. of tape. As the machine being described, merely by way of example, has 78 feeds it will be realised that punched tapes of a reasonable and easy to handle lengthcan produce a pattern area of considerable depth.

Each punched tape PT is driven by means of a roller 47 having sprocket teeth 47a at each end for engagement in drive holes 48 in the tape margins (see FIG. 1). At each end of the said roller there are 16 sprocket teeth on a circular pitch of 0.187 in. Consequently, 32 hole positions are traversed past each sensing orifice 32 in a vertical block 26 for each revolution of the corresponding toothed roller 47. If, therefore, the roller 47 is geared in such a way that it rotates twice for each revolution of the cylinders 10 and 16, then 64 hole positions will be allowed to pass each sensing orifice 32, i.e., one signal for each inclined line of patterning butts 15a. Manifestly, machines having different needle pitches and different needle cylinder diameters to those hereinbefore specifically quoted will incorporate different gearing or employ different numbers of sprocket teeth according to requirements.

For convenience of handling and loading, the tapes and their drive and guide rollers are, as previously mentioned, mounted in cassettes 45 in sets of six. Each cassette takes off a drive from the cylinder driving gear 18 which is coupled in the manner depicted in FIG. 1 directly to one of the six toothed drive rollers 47 of the set. The remaining five drive rollers 47 of the set are driven from the first by means of a timing belt (not shown) passing over pulleys mounted on each drive roller spindle.

Each punched tape PT passes between a concave rear face of the relevant vertical block 26 of fluidic elements 25 and the mating convex front face 34a of the tape guide 34, the two being lightly spring loaded together.

Referring again to FIG. 1, the particular toothed drive roller 47 shown therein is driven from the cylinder driving gear 18 through the medium of a train of spur gearing. This train comprises a pair of intermeshed rotary gears 49 and 50 the axles 51 and 52 of which are fixed in the driving gear 18. The rotary gear 49 meshes with a stationary gear ring 53 which is secured to the fixed bed plate 28. The gear 50 is integral and rotatable together with a gear 54. The latter meshes with a gear wheel 55 arranged to drive a pinion 56. Lastly, the pinion 56 meshes with a gear 57 secured to the lower end of the spindle 47b of the roller 47. The spindle 56a of the pinion 56 rotates, as also does the spindle 47b, in the fixed annular plate 27.

Each toothed drive roller 47 has co-operating therewith a plain guide roller 58, and three vertical guide pins 59, 60, and 61 extending up from the relevant base plate 46 are provided for the guidance of each tape loop. Thus, as shown in FIG. 4, each punched tape PT passes between the relevant rollers 47 and 58, around the rounded front of the tape guide 34, then around the guide pins 59, 60 and 61 in that order.

One of the major advantages of the invention is that a control system isattained without moving parts or electrical or electronic circuitry. The only mechanical movement is that which the control system initiates. It is this which leads to simplicity and low unit cost both for the knitting machine pattern programme and the selector units themselves. An air control system has the added advantage that it is self-cleaning: air is discharged through working clearances in the system which helps to disperse dust and lint around the selector units themselves and the knitting elements. Air control also results in a minimum of wear on the operating components within the selector units as they are, in a sense, working on air bearings.

We claim:

l. A multi-feed circular knitting machine comprising, in combination; an axially tricked cylinder co-axial with respect to the knitting head of the machine; individually operable needle-controlling jacks which are accomodated in tricks in the cylinder and are furnished with patterning butts, one butt per jack, said butts on successive jacks being so relatively offset laterally in a multiplicity of superimposed planes, as to form right around the machine circumferentially spaced inclined lines of the butts, the lateral offsetting corresponding with the pitch of the pattern jacks circumferentially of the machine; groups of individually movable selector cam slides, one group in advance of each feed arranged around the knitting head, and for each group of selector cam slides, programmed control means including an apertured programming element functioning at a speed related to that of the machine for selectively operating the said slides in advance of the relevant feed for effecting selective actuation of the jacks in accordance with pre-determined patterning requirements; the machine being characterized in that the vertical pitch of the said patterning butts on successive jacks is such that the lower edge of the butt on any one jack is spaced vertically from the corresponding edge of the butt on the next jack a distance equal only to the vertical pitch of the butts, whereby an individual jack can only be lifted by any one selector cam slide a distance equivalent to the said vertical pitch; and in that each of the selector cam slides in the group at a selector station in advance of each feed is operable by an air pressure system and the supply of air under pressure to these slides is controlled by said apertured programming element movable in timed relation with the rotation of the knitting head of the machine whereby the selector cam slides are air operated selectively, the air pressure system in cluding fluidic elements each consisting of a single laminate section having therein a cavity to receive one of the selector cam slides, twice as many of these fluidic elements as there are patterning butts in each inclined line of such butts being stacked one above the other to form a vertical block at each selecting station, each fluidic element having a sensing orifice in alignment with a channel or line of information in the apertured programming element.

2. A multi-feed circular knitting machine according to claim 1, said apertured programming element being a punched programming tape, and wherein the sensing orifices detect the presence or absence of holes in said punched programming tape which extends around a vertical tape guide having a mainly convex front face fitted into a concave face of the vertical block of stacked fluidic elements, said tape guide having formed therein an exhaust duct and a vertical series of as many air exhaust slots as there are fluidic elements in the stack, these slots being aligned with the lines of information in the punched tape and communicating with the interior of the exhaust duct common to them all, and wherein a vertical air feed tube in communication with a source of low pressure air extends up through the block of fluidic elements and has formed in its wall as many air feed holes as there are fluidic elements in the stack, said air feed holes being in alignment both with the corresponding air exhause slots and the respective sensing orifices, and the outer ends of the latter terminating in the concave face of the vertical block whilst their inner ends lead into channels freely communicating with the inner butt ends of the selector cam slides in the respective fluidic elements.

3. A circular knitting machine according to claim 2, wherein air under low pressure is fed into the blocks of stacked fluidic elements at the selector stations from an annular chamber formed in a fixed plate which surrounds a rotary cylinder wherein are accommodated the instruments furnished with the patterning butts.

4. A multi-feed circular knitting machine according to claim 1, wherein the selector cam slides in the group at each selector station are arranged in superimposed pairs, the first slide of each such pair having an operative end adapted by engagement with patterning butts, to raise corresponding needles to tucking height only, whereas, the second slide of the pair has an operative end which, together with the operative end of the first slide, causes patterning butts to be lifted sufficiently far as to cause corresponding needles to be raised to clearing height, the arrangement being such that the first cam slide is movable into its operative position independently of the second cam slide, which latter remains stationary, whereas whenever the second slide is rendered operative the first slide is also rendered operative together therewith.

5. A multi-feed circular knitting machine in accordance with claim 1, said apertured programming element being a punched tape, and wherein for driving an endless loop of said punched tape at each selector station there is provided a driveable roller having sprocket teeth for engagement in drive holes in the tape loop, the said rollers at adjacent selector stations being mounted in a removable cassette and wherein at least one of the driveable sprocket rollers in the cassette is driven from a cylinder driving gear through the medium of a train of gearing.

Claims (5)

1. A multi-feed circular knitting machine comprising, in combination; an axially tricked cylinder co-axial with respect to the knitting head of the machine; individually operable needlecontrolling jacks which are accomodated in tricks in the cylinder and are furnished with patterning butts, one butt per jack, said butts on successive jacks being so relatively offset laterally in a multiplicity of superimposed planes, as to form right around the machine circumferentially spaced inclined lines of the butts, the lateral offsetting corresponding with the pitch of the pattern jacks circumferentially of the machine; groups of individually movable selector cam slides, one group in advance of each feed arranged around the knitting head, and for each group of selector cam slides, programmed control means including an apertured programming element functioning at a speed related to that of the machine for selectively operating the said slides in advance of the relevant feed for effecting selective actuation of the jacks in accordance with pre-determined patterning requirements; the machine being characterized in that the vertical pitch of the said patterning butts on successive jacks is such that the lower edge of the butt on any one jack is spaced vertically from the corresponding edge of the butt on the next jack a distance equal only to the vertical pitch of the butts, whereby an individual jack can only be lifted by any one selector cam slide a distance equivalent to the said vertical pitch; and in that each of the selector cam slides in the group at a selector station in advance of each feed is operable by an air pressure system and the supply of air under pressure to these slides is controlled by said apertured programming element movable in timed relation with the rotation of the knitting head of the machine whereby the selector cam slides are air operated selectively, the air pressure system including fluidic elements each consisting of a single laminate section having therein a cavity to receive one of the selector cam slides, twice as many of these fluidic elements as there are patterning butts in each inclined line of such butts being stacked one above the other to form a vertical block at each selecting station, each fluidic element having a sensing orifice in alignment with a channel or line of information in the apertured programming element.

2. A multi-feed circular knitting machine according to claim 1, said apertured programming element being a punched programming tape, and wherein the sensing orifices detect the presence or absence of holes in said punched programming tape which extends around a vertical tape guide having a mainly convex front face fitted into a concave face of the vertical block of stacked fluidic elements, said tape guide having formed therein an exhaust duct and a vErtical series of as many air exhaust slots as there are fluidic elements in the stack, these slots being aligned with the lines of information in the punched tape and communicating with the interior of the exhaust duct common to them all, and wherein a vertical air feed tube in communication with a source of low pressure air extends up through the block of fluidic elements and has formed in its wall as many air feed holes as there are fluidic elements in the stack, said air feed holes being in alignment both with the corresponding air exhause slots and the respective sensing orifices, and the outer ends of the latter terminating in the concave face of the vertical block whilst their inner ends lead into channels freely communicating with the inner butt ends of the selector cam slides in the respective fluidic elements.

3. A circular knitting machine according to claim 2, wherein air under low pressure is fed into the blocks of stacked fluidic elements at the selector stations from an annular chamber formed in a fixed plate which surrounds a rotary cylinder wherein are accommodated the instruments furnished with the patterning butts.

4. A multi-feed circular knitting machine according to claim 1, wherein the selector cam slides in the group at each selector station are arranged in superimposed pairs, the first slide of each such pair having an operative end adapted by engagement with patterning butts, to raise corresponding needles to tucking height only, whereas, the second slide of the pair has an operative end which, together with the operative end of the first slide, causes patterning butts to be lifted sufficiently far as to cause corresponding needles to be raised to clearing height, the arrangement being such that the first cam slide is movable into its operative position independently of the second cam slide, which latter remains stationary, whereas whenever the second slide is rendered operative the first slide is also rendered operative together therewith.

5. A multi-feed circular knitting machine in accordance with claim 1, said apertured programming element being a punched tape, and wherein for driving an endless loop of said punched tape at each selector station there is provided a driveable roller having sprocket teeth for engagement in drive holes in the tape loop, the said rollers at adjacent selector stations being mounted in a removable cassette and wherein at least one of the driveable sprocket rollers in the cassette is driven from a cylinder driving gear through the medium of a train of gearing.

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