US3022652A - Control mechanism for circular knitting machines - Google Patents

Description

Feb. 27, 1962 c. H. WAlNWRlG HT ETAL 3,022,652

CONTROL MECHANISM FOR CIRCULAR KNITTING MACHINES 6 Sheets-Sheet 1 Filed Feb. 24, 1960 ventors M /ttorney Feb. 27, 1962 c. H. WAINWRIGHT ETAL 3,022,652

CONTROL MECHANISM FOR CIRCULAR KNITTING MACHINES Filed Feb. 24, 1960 6 Sheets-Sheet 2 Attorney Feb. 27, 1962 c. H. WAINWRIGHT ETAL v3,022,652

CONTROL MECHANISM FOR CIRCULAR KNITTING MACHINES Filed Feb. 24, 1960 e Sheets-Sheet s In ven t or:

.A'Jww/ ttorney Feb. 27, 1962 c. H. WAINWRIGHT ETAL 3,022,652

CONTROL MECHANISM FOR CIRCULAR KNITTING MACHINES Filed Feb. 24, 1960 6 Sheets-Sheet 4 Inventors UMn/MW By 2414 M ttorn e y Feb. 27, 1962 c. H. WAlNWRlGHT ETAL 3,022,652

CONTROL MECHANISM FOR CIRCULAR KNITTING MACHINES 6 Sheets-Sheet 5.

Filed Feb. 24, 1960 5 I LJI y Attorney IIIUBCIIOP' 7/ Feb. 27, 1962 c. H. WAINWRIGHT ETAL 3,022,652

CONTROL MECHANISM FOR CIRCULAR KNITTING MACHINES Filed Feb. 24, 1960 6 Sheets-Sheet 6 85 F/ G. /5. 44 2/ 88 I 2/ as Qg [I p jaljvqntoU, 5

Home y United States Patent 3,022,52 CQNTRQL MECHANISM (CERfiULAR KNITTING MACEIEQES Carlyle Herbert Wainwright and Frederick Edward Deans, Leicester, England, nssigncrs to The Bentley Engineering ornpany Limited, Leicester, England Filed Feb. 24, 1959, Ser. No. 19,635 Claims priority, application reat Britain Feb. 23, 195'? 6 Claims. (Cl. 66--154) This invention is or improvements in control mechanism for circular knitting machines and is concerned with a mechanism or attachment whereby actuation of bolt cams, feeders and similar instrumentalities at one or more feeding stations can be effected. One object of the invention is to provide a mechanism or attachement of this character which has a relatively compact construction and is capable of controlling avariety of coordinated actuations of instrumcntalities.

The controlling of knitting at one or more feed points is frequently achieved by control mechanisms adjustable to secure changes in actuation of the knitting instrumentalities from time to time. Such a mechanism is disclosed in US. Patent No. 2,745,269. Basically these mechanisms have a main shaft carrying cam-s which are racked around intermittently, each cam having a camv follower attached to a lever which transmits a push or pull to the various devices such as bolt cams, feeders and trappers in order to introduce and withdraw them at the appropriate times as iswell known for ei'recting knitting changes such as striping, introducing a draw thread, 'etc. timed or regulated to take place at certain desired places during the manufacture of the article, also when striping and a new yarn is introduced the old yarn must be with drawn, out OE and trapped. In the mechanisms just mentioned the cams are split into small assemblies known as packs and each pacl; may comprise two cams, one controlling a feeder, the other a trapper (working in conjunction with the feeder), and a rack wheel. There would be one such pack for each yarn required to be introduced and each bolt cam to be operated. Each pack is racked around a common shaft by a separate pawl and these pawls are usually assembled side by side in a con mon carrier which oscillates constantly whilst the machine is in motion. In order to prevent the rack Wheels being racked with every stroke of the carrier the pawls are equipped with a feeler like err-tension which engages a bar which extends the length of the attachment. This bar, known as a selector bar, bluffs or holds the pawls away from the teeth of the rack wheel when racking is not desired. The selector bar has notices or steps out along its length which provides different heights on which the feeler of the pawl may rest, the bar being moved lengthwise to present the steps to the feeler in amanner referred to more fully in U.S. Patent No. 2,745,269. The notches are arranged in a staggered fashion so that by moving the bar varying amounts only certain pawls are lowered by their feelcr to engage the teeth of the rack wheels.

A disadvantage of the selector bar is that the number of pawls which can be individually controlled by a bar of a reasonable iength is limited due to the method of selection; in other words the more packs of cams and associated racking pawls are used the wider apart must they be spaced, or conversely the smaller must'be the lengthwise movements of the selector bar. As it is not These knitting changes must of course bev mon axis and each comprising a ratchet wheel and at least one edge cam secured thereto, pawls movably mounted on a common oscillatory pawl carrier to cooperate respectively the ratchetwhcels of the cam packs and cam followers adapted to be actuated respectively by the cams of the cam packs when racked by their.

pawls to efiect adjustments of said instrumentalities, and having rotary pawl selecting means for selectively controlling engagement of the pawls with their associated ratchet wheels. By this form of construction theendwise extent of the mechanism can be kept within reasonable limits and is independent of the number of alternative selecting adjustments required. Further the rotary means of efiecting selections tends to increase the scope of the mechanism enabling it readily to cater for a larger numberof alternative selection settings.

In a preferred arrangement the pawls are normally held out of engagement with ratchet wheels and are selectively released for engagement therewith by rotary adjustments of said selecting means. The pawl selecting means may comprise a plurality of discs mounted to turn in unison and having stepped peripheral formations suitably positioned to actuate their respective pawls as required in different rotary settings ofthe selecting means.

In a preferred form of construction each ratchet wheel is formed with high and low teeth arranged in alternation and the discs of the rotary selecting means have stepped formations of different depths whereby the pawls during their oscillation with the carrier may be caused to miss the ratchet wheels entirely, engage high teeth only, or engage low as well as high teeth as and when required. The peripheries of the discs of the pawl selecting means may cooperate with followers providing tracks against which tails of the respective pawls ride during oscillation of the latter with the pawl carrier to control their positions for missing or engaging the teeth of the ratchet wheels.

in a convenient construction an assembly of discs forming t e awl selecting means mounted to turn in unison is secured T0 a boss and is urged yieldably to an inoperative setting by a spring extending from a fixed anchorage and reaching partly around said boss and a further boss secured to the assembly of the discs has a flexible connector secured to and wound partly around said further boss and connected at its other end to an operating lever by means of which the turning movement of the set of discs is effected to move the discs to different settings.

Further provisions of the invention relate to a convenient assembly of the mechanism and the provision of a plurality of mechanisms in a single unit.

A preferred form of construction in accordance with the invention is illustrated by way of example in the accompanying drawings and will now be described with reference to the drawings in which,

FIGURE 1 is a side elevation of an opposed cylinder Patented Feb. 2?, i962 show certain of the working parts;

FIGURE 4 is a front elevation on a somewhat larger scale of the main c-am assembly of the control mechanism;

FIGURE 5 shows in end view an assembly of two cams and a rack wheel for operating bolt cams, and will be described as a bolt cam pack;

FIGURE 6 is an outline plan view of parts shown in EEG. 5;

FIGURES 7 and 8 are views similar to FIGS. 5 and 6 of an assembly referred to later as a draw thread cam pack;

assembly referred was a middle feeder cam pack;

FIGURES ll and 12 we further similar views showing anassembly referred to as a top feeder cam pack, and FIGURES 13 to 1 6 are views showing selecting cam discs for selecting respectively a bolt .cam'pack and draw thread, middle feeder and top feeder cam packs.

The machine selected for illustration of the invention is an opposed cylinder circular knitting machine suitable for knitting hosiery, e.g. socks, and comprises bottom and top needle'cylinders 8 and 9 supported respectively on a bed plate 2 and a top plate 9a and having a bottom cam FIGURES 9 and 10 are corresponding views of an the main cam assembly having been partly removed to 7 box 8a and a top cam box 9b, the bottom cam box 8a I being supported on the bottom cylinder 8 in the manner described in US. patent application Serial No. 837,550,

filed September 1, 1959. The machine is provided with a three knittingstations spaced around the cylinder aids and the control mechanism illustrated is usedto control instrumentalities at the second and third knitting stations. It is to be understood that the invention is equally applicable to other forms of circular machine and the control mechanism may be employed for actuating instrumentalities at a single knitting station.

The control mechanism is in the form of an attachment, the main casing of which is indicated at 1 in FIG. 2. It is bolted to the underside of the bottom bedplate 2 at the points 3 and 4. The attachment is split into two units, which although driven from a common shaft may be caused to operate independently.

The drive is obtained from a gear wheel 5, FIG. 2; which is attached to a vertical bevel gear 6 which drives a horizontal bevel gear "1', FIG. 1, for rotating and recip-' rocating the needle cylinders 8 and 9 as is usual in the type of machine illustrated. The gear wheelS transmits the drive through an intermediate gear 16 to a gear wheel 11 which is fixed to a shaft 12. There are two eccentrics 13 and 14 fixed to this shaft, one of these, viz. 14 is indicated by dotted lines in FIG. 3 from which the operation of the attachment can be most easfly understood. The attachment comprises two similar units divided by a wall or web 15 and for convenience the following description will be concentrated on the right hand unit. The eccen tric 14 on the shaft 12 is shown contacting a wheel 16, preferably in the form of a ball or roller bearing, which is mounted on a small shaftsecured to a cradle-like pawl left hand unit the relative timing of the eccentrics being d to the positions of the corresponding knitting stallOIle.

In the leading edge of each carrier 13, three slots are cut in which racking pawls 1.9 are located and rock about a shaft 29 on the carrier. There is one pawl mounted on the extreme end of the shaft and three in the slots making four racking pawls in each carrier 18. Each pawl has a tail 1% which rides upon the upper surface of a cam disc follower 21 and is urged into contact with this surface by a spring 22 as shown. The carrier 18 is shown in FIG. 3' in its backward position and as it rocks forwards the tails 19a of the pawls will ride down the slope 21a of the cam disc follower 21 causing the noses 19b to move inwards towards the rackwheels 23 of the cam packs. These cam packs are similar to those used in the known attachments previously described (such as illustrated in U.S. Patent No. 2,745,269) excepting that in this instance they are pushed around the shaft by the pawl acting upon the rackwheel instead of being pulled around the shaft by a claw type pawl. As illustrated in FIGS. 5 and 6 a typical pack has a rackwheel 23 which is fixed by screws 24 to one end of a core or sleeve 25. The two cams 26 and 27 are mounted on this core and each cam has a keyway and two adjusting screws 28 and 29, the keyway being clear of the key 30 in the core to allow the cam a limited angular movement for timing purposes, the cam being finally clamped to the 'key by locking up the screws 24. Thus each cam can be adjusted angularly with respect to-the other and the rack wheel; As can be seen in FIG. 5 the rackwheel has eight teeth, four high teeth spaced at 90 and four low teeth, each low tooth being interposed between two high teeth. Only one cam pack (i.e. the bolt cam pack illustrated in FIG. 5) is shown mounted on the shaft 31 shown chain-dotted in FIG. 3. The other cam-packs .(shown assembled in FIG. 4) have been omitted fromFIG. '3 to enable other mechanism to be more clearly shown.

I It maybe stated herethat the extreme right hand corner or" the right hand carrier 18' has been broken away to enable the tail of the pawl to be seen contacting the upper surface of the cam follower. A complete carrier is shown in the left hand section of the attachment.

The packs of cams and rackwheel are mounted side by side as shown by the heavy chain dotted lines in FIG. 4 and indicated as a, b, c, d forthe left hand section and e, f, g, h for the right hand section of the attachment. A spacing collar 32 bridges the gap formed by the web 15 FIG. 3. Each pack is free to revolve when its rack wheel is engaged but is restrained from accidental turning by friction discs33 between each two adjacent packs, pressure being exerted by a compression spring 34 and an adjustable threaded disc 35 which urges all the packs in the direction of the end wall 36 of the attachment.

At the bottom of the attachment a shaft 38 is secured between the end walls of the casing 1 and mounted on it are two tubes 39 and 40 FIG. 2 which are located be- 1' tween each end wall and the central web 15 of the casing.

the ends of a rod 44 are located. This rod is threaded through the holes in the discs and locates their camming surfaces with respect to one another, and causes all of the discs to be turned together when the tube 40 is rotated. Around collar 43 a tensioned spring 45 is partly wrapped, and has one end attached to the collar and the other to a rod 46 disposed between the end walls of the casing 1. This spring urges the shaft and discs to rotate but they are prevented from doing so by. a chain 47 pass= .ing around and anchored to the collar 42 the other end of the chain being attached to an arcuate chain lever 48. From this it will be seen that as the chain lever pulls on the chain (in a manner to be described later) it will rotate the discs against the action of the spring 45, and by controlling the extent of the pull the discs may be ro-, tated to the various positions in which the followers 21 may rest on the different steps cut in the periphery of the discs. As the followers 21 are lowered or raised step by step the tails 19a of the pawls 19 co-operating with the upper surface of the cam followers 21 are also lowered or raised thus causing the nose 19b of the pawls to move inwards towards the rack wheels 23 or outwards away from the rack wheels.

It can be seen in FIGS. 13 to 16 that each selecting disc (regardless of the shape of the camming surfaces) has three different levels. Thus each disc (depending upon the angular distance through which it is rotated) is capable through the medium of its follower 21 of moving the nose of its associated pawl to three positions. When the follower is resting on the top or maximum diameter of the disc (as shown in FIG. 3) the pawl nose will pass idly clear of the teeth of its rack wheel; when the follower is resting on the first step of the disc the pawl nose will be positioned to engage the high teeth only of the rack wheel; and when the follower is resting on the bottom level of the disc the pawl nose will be positioned to engage both high and low teeth of its rack wheel. As the pawls are oscillating continuously whilst the machine isin motion, partial rotating of the discs can cause the pawls to miss the teeth of the rack wheels, engage high teeth only or engage both high and low teeth, each pawl which engages ratchet teeth serving to rack its own particular cam pack. i

As the four discs of each section are rotated together through the various angular distances, the steps on their peripheries are cut in relation to one another to allow only certain selections to be made at each angular position to which they are rotated. For instance in F168. 13 to 16, an example of one selection (in this case the draw thread selection) is shown, the reference 85 indieating in each case the position in relation to its disc of each follower during this selection, and showing the following settings:

Disc for selecting bolts (FIG. 13), follower on bottom level, pawl racking low tooth.

Disc for selecting the draw thread feeder and trapper (FIG. 14).

Follower on bottom level, pawl racking low tooth.

Disc for selecting middle feeder (FIG. 15 follower on top level, pawl missing all teeth.

Disc for selecting top feeder (FIG. 16), follower on top level, pawl missing all teeth.

The means for partially rotating the discs will now be described. The chain 47 which pulls the discs round has one end attached to the arcuate chain lever 43 having a collar 49, FIG. 3 firmly fixed to its upper end and secured to a shaft 50. A similar arcuate lever 51 in the left hand section of the attachment has its collar 52 fixed to a tube 53 which turns freely on the shaft 50. The tube 53 has a bearing in the wall 36 of the casing 1 and the shaft St? has a bearing in the web 15. Thus each lever may be controlled separately by partially rotating the tube 53 or shaft 50. A bracket 54, FIG. 2, is attached to the back of the machine and forms a bearing for the other end of the shaft 50, collars 55 and 56 fixed to the shaft preventing endwise movement in the bracket. Two similar forked levers 57 and 58 FIGS. 1, 2 and 3 are screwed to the shaft 50 and tube 53 respectively, and located in the slot in each lever are pins 59 and 60 (seen best in FIGS. 1 and 2) each attached to one arm of respective bell crank levers 61 and 62 which are themselves mounted on a shaft 63 secured to the bracket 54 (FIG. 2). The other arms of the levers 61 and 62 contact horizontal push rods 63 and 64. From this it can be seen that by pushing on the ends of therods 63 and 64 protruding at the front of the machine the arcuate levers 48 and 51 are operated to pull on the chains 47 and partially rotate the selector discs, and by moving the rods in steps the discs will be turned through certain angular distances also step by step, as required in the manner previously described.

It may be found in practice that it is an advantage to provide a means for positively registering the discs to position them in their diiferent settings just for the period in which the pawls 19 are advancing to rack, to avoid possibilityof mis-racking in the event of'a variable amount of play occurring in the various connections or on the other hand any tendency arising for the discs to overrun due to a. too rapid movement of the arcuate levers 48 or 51.

A simple way of registering the discs would be to provide an extra disc on each of the tubes 39 and 46 to turn with the other discs and provided with peripheral teeth at the selection settings, and a check pawl spring urged to engage such teeth. It would benecessary of course to provide a means for lifting this check pawl immediately after each racking movement of the pawl carrier 18 because the selector discs must only be retained in their selecting position during one forward movement of the pawl carrier. If allowed to remain longer the pawl would continue to rack the selected rack Wheel and cam pack on each forward stroke of the carrier. Means for lifting the check pawl could take the form of a projection attached to the pawl carriers 18 in such a position that as each carrier is nearing-the end of its forward racking movement the projection contacts the check pawi and lifts it out of engagement with the toothed disc thus allowing the selection discs to return to their out of action position under the action of springs 45, tension having been released in the chain 47 due to racking off a stud in the pattern chain mechanism or dropping off a cam on themaindrum as will now be described.

The intermittent movement of the push rods 63 and 64 previously described for rotating the discs to various selecting positions can be obtained by using a pattern chain mechanism of known type (e.g. one as shown and described in US. Patent No. 2,463,639) briefly consisting of an attachment for advancing one or more pattern chains step by step to enable studs or projections of different heights to be positioned under followers attached to levers having arms which co-operate with the push rods to push (or release) the said push rods distances pro-determined by the arrangement or order of the studs of the pattern chains. Control of these push rods can also be obtained from suitable cams on the main drum of the machine such as one shown in FlG. 1 and identified by the number d5. This cam will act on a follower 65a of a lever 665 to push on an adjusting screw 67 in the push rods. There are two such levers mounted on a trip lever shaft 68 FIGS. 1 and 2, one for each push rod. Associated with each of these levers can be seen a bell crank lever 69 coupled to one arm of which is a link 7t) (shown broken) leading to a pattern chain attachment. The other arm 69a of each cell crank lever 69 has an adjustment screw 72 which transmits the movements obtained from the chain studs via the arm of the associated lever 65 to the respective push rod.

FiG. 3 shows a typical pair of cam actuated levers 72 and 73 rockably mounted on shaft 119 and having cam followers co-operating with the pair of cams of the bolt cam pack indicated at e in FIG. 4 and shown in detail in FIGS. 5 and 6. As the cams are racked in the direction of the arrow X the followers will ride up the lobes thus depressing the arms 72a and 73a of the levers and exerting a pull in the connecting links '74 and 75. When the foilowers'drop off the lobes of the cams the lever arms 72:: and 73a are raised by tension springs 76 and 77. FIG. 1 shows links 75 as attached at its upper end to a horizontal lever 78 which is fulcrumed on a shoulder screw 79 in a fixed block 80 which is itself secured to the bottom bedplate 2. The other end of lever 78 has a slot in which the shaped end 81 of a second lever is located, this second lever is fulcrumed on shoulder a screw 32 also in the fixed block 83 and has attached at its other end the vertical adjustable connecting rod 83 which in turn is attached at its upper end to a bell crank lever 84 which is used to withdraw (against the action of an internal spring) a bolt cam in the bottom cam box in known manner.

Although, for the sake of simplicity in the drawings, only the two levers 72 and 73 FIG. 3 have been shown co-operating with a cam pack it will be realised that there will be two such levers for each cam-pack and these levers will be positioned alongside those shown and mounted on the same shaft119 on both sides of the web 15, those on the left hand side of the web co-operating with the. cam-packs on the left hand section and those on the right with the cam-packs of the right hand section. The means for transmitting the movements provided by the cams to the various bolts, feeders, etc. need not necessarily be by linkages as just described, but may conveniently be in the form of Bowden cables or a combination of both as shown in FIG; 3 where three cables are shown. The covers of the latter are secured, in adjustable screwed adaptors in a projection of the top of the main casing 1,' the nipples of the cables being connected to the horizontal arms of levers such as 72a and 73a.

Havingdescribed in detail the working of the attachment with an example of the controlling connections be: tween it and one bolt cam in the bottom cam box it, is, now appropriate to explain the completeoperations or controlling movements of which the attachment is capable.

In FIG. 3 there are shown eight selection discs, four in each section of the attachment, indicated at a, b, c, d and e, f, g, h to correspond with the cam-packs a to h with which they are associated. The left hand section controls knitting at the second feed station and the right hand section controls knitting at the third feed station. Considering the left hand section containing selector discs a, b, c, d, the cam discs followers 21 can be seen in FIG. 3 resting on the top diameters of the discs, in which position the pawl carrier will beracking idly,

the tails of the pawls being in a raised position on the top surfaces of the cam followers as described previously. Supposing for example an article of hose is being com menced and it is required to knit a draw thread as usual after the waste courses and just prior to knitting the welt, the machine will be knitting l x 1 rib fabric on alternate needles in the top and bottom cylinders, yarn being fed to these needles at a first or front feed position. To knit a draw thread a bolt cam must be introduced to defleet bottom cylinder needles to knit at a second feed point, and a feeder must be advanced to introduce yarn to these needles, therefore at the appropriate time the main drum of the machine is racked to bring a cam such the aforementioned levers, tube and arcuate lever) the disc shown at a in FIG. 3 and a detail in FIG. 13 to turn partially until the follower 21 is positioned as indicated at 85 in FIG. 13 which is the bottom position in which, upon the forward swing of the pawl carrier, its associated pawl will rack 21 low tooth of the rack wheel of cam-pack a shown in detail in FIGS. 5 and 6.

As can be seen in FIG. 5 there are four similar lobes to each of the cams so that each time a low tooth is racked these lobes or cam surfaces will be presented to the cam followers (the followers being similar to those of levers 72 and 73 in FIG. 3). Thus when follower 21 rests at positions 85 (FIG. 13) on disc a one of the four sets of lobes of cam pack a FIG. 5, will causelthrough associatedlevers and connecting links), a bolt cam in each of the top and bottom cam boxes to be introduced. The

will be racked back to their original positions.

bolt cam in the top cam box will not however effect the needles of the top cylinder as they are in a non-knit ting track at this time, only the needles of the bottom cyl nder being caused to take the draw thread yarn. Whilst introducing the bolt cams it is necessary that the draw thread feeder be advanced to feed position and the trapper opened to release the yarn and this is accomplished in similar manner and in the same forwardrnovo ment of the pawl carrier. The selector disc marked b in FIG. 3 shown in detail in FIG. 15, having been partially rotated wtih disc a, has its follower 21 positioned as at in FIG. 14 so that its pawl will be positioned to rack a low tooth of the rackwheel associated with cam pack b. This racking movement will present a gap between two of thefour identical lobes of the feeder cam 86 FIG. 7 to the follower of a lever similar to 73 in FIG. 3 and also present a lobe of the trapper cam 87 FIGS. 7 and 8 to the follower of a lever similarto 72, and through associated links and levers not shown will advance the feeder to feed position and will open the trapper to release the end of the yarn. The yarn will then be taken by the bottom cylinder needles acted on by the bolt cam just introduced. The other two discs 0' and d FIG. 3 will also be partially rotated together with disc a and b but as their followers 21 will be positioned on the top surface of the discs as shown at '85 in FIGS. 15 and 16 their associated pawls will still be raised to pass idly over the, teeth of their respective rack wheels. I

For the reason mentioned previously, the selector discs must only be held intheir. selecting position during one forward movement of the pawl carrier, audit is necesas 65 in FIG. 2 to pass-under the follower 66a of the lever 66 to cause the selector discs to be partially rotated and maintain them in this position during one. forward movement only of the pawl carrier. In other words the drum cam must not permit the follower 66a to dwell on it any longer than it is required to hold the selector discs to cause one rack of the selected cam packs.

After the draw thread has been knitted, the main drum is racked to pass another cam such as 65, FIG. 2, under the follower 66a to cause the selector discs to select the cams required to move the bolts, feeder and trapper to their original positions. Now it will be recalled that only certain cam packs have been racked, i.e. the bolt cam pack (FIG. 5) and the drawthread feeder and trapper cam pack (FIG. 7). Therefore these two packs will have the high teeth of their rack wheels positioned under the pawls whilst the two cam packs viz., middle feeder pack and top feeder pack will have their low teeth positioned under the pawls as they were not selected the last time. It will therefore only be necessary partially to rotate the discs to the'position in which their followers engage them at 38 in FIGS. l3 to 16. In this position, that is with all the followers resting on the first or mid-level step, all the pawls will be actuated to engage high teeth only and so only the bolt cam pack and feeder and trapper cam pack Thus the bolt cams will be withdrawn and the drawthread feeder will be retracted to its trapping position and its trapper will cut and hold the yarn, thus completing the sequence of events in the knitting of a draw thread.

A method similar to that of knitting a draw thread is used when the knitting of stripes or the introduction of a different yarn is required, but dilferent cam packs must of course be selected, the angular position of the selector discs being varied by different heights of cams on the main control drum or difierent heights of studs on the pattern chains. To knit spaced bandsv each of a different colour. at, for example, the second feed the following sequence of events would take place: a 7 First: The selector discs of the left hand section (FIG. 3) turned to a setting to allow only the bolt cam pack a, FIG. 4, and one of the two feeder and trapper cam packs and d (shown in detail in FIGS. 9 and 10,. 11 and 12) to be selected for racking and the discs are then returned to their original non-selecting position, having caused the bolt cam, feeder and trapper to have been actuated.

Second: After the required number of courses have been knitted and a yarn change is desired the selector discs are moved to a setting such that the packs 0 and d are both selected; now assuming pack 0 was selected on the previous rack and its feeder is now knitting, this rack will withdraw the feeder and trap the yarn whilst the feeder controlled by pack d will have advanced to replace it with a different yarn. The bolt cams will remain in during striping changes, and the discs are immediately returned to non-selecting position.

Third: When the required number of stripes or hands have ben knitted the selector discs are moved to a setting wherein the cam pack for operating the feeder and trapper now in action are selected and racked. This rack will withdraw the bolt cams, retract the feeder and close the trapper. Thus knitting will be terminated at the second feed position, the discs being at once returned to their original non-selecting position.

As already mentioned the left hand side of the attachment with selector discs a, b, c, d, FIG. 4, controls knitting at the second feed and the right hand section with discs e, f, g, it controls knitting at the third feed. The foregoing description of effecting striping at the second feed could equally apply to the third feed but using of course the right hand section of the attachment. Both sections may be functioning together or individually as required] j The fact that-the cam-pack rack wheels have alternating high and low teeth is a feature of the attachment which permits the cam-packs to be zeroed to render the various knitting elements they control out of action simultaneously at will. As has been observed the action of racking any low tooth puts the controlled element (e.g. a feeder) into use and racking any high tooth puts it out of use. It is therefore only necessary to position a cam such as 65 FIG. 1 at a suitable height on the main drum to cause the selector discs to move to a position where their followers 21 rest on the first step, so that their associated pawls will all rack any high teeth which may be presented, in order to rack simultaneously the elements they control out of action. It is usually desirable to provide such a cam on the drum in the position corresponding to the start of a complete article of hosiery to ensure that at that time the cam-packs are zeroed, i.e. in inoperative settings.

The following is a list of the instrumentalities controlled by the individual selector discs and cam-packs in the preferred construction shown but it will be understood that it can be varied to suit individual requirements:

Selector disc a controls cam-pack a which operates 2nd feed top and bottom bolt cams.

Selector disc b controls cam-pack b which operates 2nd feed draw thread feeder and trapper cam.

Selector disc c controls cam-pack c which operates 2nd feed middle feeder and trapper cams.

Selector disc d controls cam-pack d which operates 2nd feed top feeder and trapper cams.

Selector disc e controls cam-pack e which operates 3rd feed top and bottom bolt cam.

Selector disc f controls cam-pack 1 which operates 3rd feed bottom feeder and trapper cams.

Selector disc g controls cam-pack g which operates 3rd feed middle feeder and trapper cams.

Selector disc 11 controls cam-pack It which operates 3rd feed top feeder and trapper cams.

It will be noted that the draw thread is controlled by a selector disc and cam pack in the left hand section of the attachment only, its place being taken by a bottom striping feeder in the right hand section.

From the foregoing description it will be realized that the control mechanism in accordance with the invention is of relatively compact construction and eminently suited to the making of a plurality of alternative selections to etfect changes in the knitting operation as and when required. By reason of the employment of rotary selecting discs the endwise spacing'of the selecting elements and cam-packs is in no way dictated by the number of alternative selections to be made or instrumentalities to be actuated and consequently an attachment capable of effecting a substantial number of alternative selections (which require only the same number of relatively closely spaced rotary settings of appropriately contoured selector discs) can be accommodated in a reasonably small space.

What we claim is:

1. For a circular knitting machine, control mechanism for selective actuation of control means comprising a supporting frame, a cam pack spindle on said frame, a plurality of cam packs mounted side by side on said spindle to turn about the axis thereof and each comprising a rachet wheel and at least one edge cam secured thereto, cam disc followers cooperating respectively with the cams of the cam packs, an oscillatory pawl carrier mounted on said frame, pawls, the tails of which ride on the upper surfaces of the cam disc followers, mounted on said pawl carrier to cooperate respectively with the rachet wheels of the cam packs and which rack the appropriate cam packs to effect machine adjustments through the action of the cam disc followers cooperating with the cams of the cam packs, and a rotary pawl selecting means comprising a plurality of discs having stepped peripheral formations positioned to actuate their respective pawls as required in different rotary settings of the pawl selecting means, and mounted on the frame for selectively controlling engagement of the pawls with the rachet wheels of their associated cam packs.

2. Mechanism according to claim 1 wherein each ratchet wheel is formed with high and low teeth arranged in alternation and the discs of the pawl selecting means have stepped formations of different depths whereby the pawls during their oscillation with the pawl carrier may be caused to miss the ratchet wheels entirely, engage high teeth only, or engage low as well as high teeth as and when required.

3. Mechanism according to claim 1 wherein selector followers engage respectively with the peripheries of the discs of the pawl selecting means and provide tracks against which the tails of the respective pawls ride during oscillation of the latter with the pawl carrier.

4. Mechanism according to claim 1, wherein, a boss is secured to the pawl selecting discs, a biassing spring being wrapped partly around said boss and connected at one end thereto, an anchorage for the other end of said spring whereby the spring is tensioned to urge the discs yieldably to an inoperative setting, a further boss attached to the discs, a flexible connector partly wrapped around said further boss and attached at one end thereto and a lever connected to the other end of said flexible connector and operable to effect through said connector selecting adjustments of the discs. 7

5. For a circular knitting machine, control mechanism for selective co-ordinated actuation of controlling instrumentalities, comprising a casing, a spindle mounted therein, a cradle-like pawl carrier pivoted within the easing on the spindle, a second spindle mounted in said casing parallel to the first spindle, an assembly of cam packs individually rotatable on said second spindle, and each comprising a cam and a ratchet fixed thereto, friction applying means to resist undesired turning of said cam packs, pawls on the pawl carrier'to co-operate respectively with the ratchets of said cam packs, cam followers co-operating with the cams of the cam packs and pivoted on the spindle supporting the pawl carrier, means yieldably urging said cam followers to engage said cams, a third spindle mounted in the casing parallel to said first and second spindles, an assembly of selector discs mounted on said third spindle, tails on said pawls, selector 3,022,662 11 i 12 p followers co-operating respectively with the discs and the units being mountedv on common spindles each exadapted to engage the tails of said pawls, means for adtending through the plurality of units.

justing the rotary setting of the selector discs and means V for oscillating the pawl carrier. References Cited in the file of this patent 6. Mechanism according to claim 5 wherein the cas- 5 UNITED STATES PATENTS ing forms a mounting for a plurality of units each comprising a pawl carrier and associated pawls, cam packs, 2 2? et 3:, g

selector discs and followers, the corresponding parts of st-it fever-

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