US3641786A

US3641786A - Patterning mechanism for multifeed circular knitting machines

Info

Publication number: US3641786A
Application number: US817930A
Authority: US
Inventors: Henry S Burdett; Ronald Harris
Original assignee: STIBBE MACHINERY Ltd
Current assignee: STIBBE MACHINERY Ltd
Priority date: 1968-05-03
Filing date: 1969-04-21
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15
Also published as: CH493667A; FR2007781A1; DE1921929A1

Abstract

A multifeed circular knitting machine with heightwise movable elements which are radially movable selectively into cylinder tricks. In same trick as each element there is a presser jack having a single patterning butt. For action on the patterning butts there are rotary drums, one per feed, provided with protruding teeth arranged in circumferential series located in superimposed planes normal to drum axis. Bolt cams, acting on height selection butts on presser jacks, shift latter upwards and downwards to dispose their single patterning butts in predetermined planes. Each drum preferably tricked to accommodate inserts furnished with the teeth. Patterning jacks are of different forms and operate in conjunction with appropriate dispositions of the patterning butts for half-gauging.

Description

United States Patent Burdett et a]. 1 Feb. 15, 1972 [54] PATTERNING MECHANISM FOR 3,077,756 2/1963 Widdowson et al... ..66/50 B L KNITTING 3,224,227 12/1965 Beckenstein .,.66/50 A g g f g g CIRCU AR 3,315,494 4/1967 Farmer ..66/50 721 Inventors: Henry s. Bnrdett, Oadby; Ronald Harris, FOREIGN PATENTS R APPUCAnONS Leicester, both of England 996,291 6/ 1965 Great Britain ..66/50 B 1,113,296 /1968 Great Britain. ...66/5O B [73] 2;? Lemme" 1,230,961 12/1966 Germany ..66/50 13 [22] Filed; Apr 21 19 9 OTHER PUBLICATIONS PP 817,930 German Printed Application No. 1,230,961 Nuber. 12/66,

66/ 50B Fm'eign Application Priority Dam Primary Examiner-Wm. Carter Reynolds May 3, 1968 Great Britain ..20,99 5/68 y yl r & Hinds Aug. 21, 1968 Great Britain ...39,958/68 Dec. 27, 1968 Great Britain ..6l,532/68 ABSTRACT A multifeed circular knitting machine with heightwise mova- U-Sr B, bl elements are movable selectively into 51 Int. 01. ..D04b 15/74 cylinder men In Same nick as each element there is a prewar [58] Field of Search ..66/25, 36, 50, A, 50 B, jack having a single patterning bum For action on the panerm 66/156 ing butts there are rotary drums, one per feed, provided with protruding teeth arranged in circumferential series located in [56] R i r n s Clled superimposed planes normal to drum axis. Bolt cams, acting on height selection butts on presser jacks, shift latter upwards UNITED STATES PATENTS and downwards to dispose their single patteming butts in 2,208,698 7/1940 Lawson et a1. ..66/50 B predetermined Planes Eaeh drum Preferably tricked t9 2,269,288 1/1942 Saftlas et a1 ..66/50 A eemmedete inserts furnished with the teeth- Pettemingjeeks 2 579 161 12/1951 Teague ..66/50 B x are of different forms and operate in conjunction with pl 2 10 l 1 9 57 "66/50 3 propriate dispositions of the patterning butts for half-gauging. 3,004,413 10/1961 Felker ..66/50 B In Claim 29 Drawing gum 80 60s l was 5 I 73 5/ 62 74 PAIENTEUFEB 15 m2 3. 641 .786

SHEET [:5 HF 13 PATENTEBFEB 15 I972 SHEET OSUF 13 PATTERNING MECHANISM FOR MULTIFEED CIRCULAR KNITTING MACHINES This invention relates to patterning mechanism for multifeed circular knitting machines.

The invention is concerned with patterning mechanism of the general class having a selective action upon stitch forming or other appropriate elements of the machine requiring to be controlled or influenced for producing patterning effects in tubular knitted fabric.

The term multifeed" is intended to be sufficiently broad to cover a circular knitting machine having a number of feeds which is large in relation to the cylinder diameter; it is primarily the intention to apply the invention to a so-called super multifeed machine having as many as, say, 48 or more feeds.

In particular, the invention has reference to a patterning system of a previously proposed character comprising, in combination, (a) elements movably mounted in tricks or grooves in a cylinder, said elements having butts and, in addition to being selectively movable heightwise and controlled or influenced by cams acting on the butts for producing patterning effects, being also capable of movement radially into their tricks or grooves towards the axis of the cylinder so as to initiate the selective actuation, (b) presser jacks arranged in the same tricks or grooves as, and in front of, either the elements (a) themselves or intermediate jacks between the presser jacks and the said elements, there being one presser jack to each such element or intermediate jack, as the case may be, and the stem of each presser jack being furnished with only one patterning butt, (c) rotary patterning units presenting circumferential series of radial teeth in superimposed planes for action on the patterning butts, one unit per feed, adapted to be driven in timed relation with the cylinder, the said radial teeth acting on the patterning butts suchwise as to press in selected presser jacks and thus effect, directly or indirectly, inward radial movements of the aforementioned elements into their tricks or grooves, the rotary units being fixed so far as any movements thereof towards and away from the presser jacks are concerned, and (d) variable presser jack moving means for shifting the presser jacks longitudinally upwards and downwards to dispose their single patterning butts opposite to radial teeth in predetermined planes.

Thus, with the machine running, the said rotary units are all in action and operative, so that immediately any particular presser jack is raised or lowered to dispose its single patterning butt at a height coincident with a plane containing a circumferential series of teeth, then if there is a tooth at the relevant location it will act on the said patterning butt and push the presser, and hence also the associated element, or the intermediate jack, back into its trick or groove with the result already described herein.

Although there is no limitation in this respect the elements of the machine to be controlled or influenced by the patterning mechanism of this invention will usually be either independent slidable needles, or associated jacks or sliders. Thus, when the elements concerned are needles in a cylinder, the purpose of the said patterning system is to determine the manner in which predetermined needles operate at relevant stations at desired times, e.g., as to whether such needles clear and knit, miss or tuck, and so on, according to patterning requirements.

Again, although the invention is primarily applicable to a multifeed circular knitting machine of the rotary needle cylinder type with a relatively stationary cam box, it would be possible to apply it to a rotary cam box type of machine with a stationary cylinder.

Heretofore multifeed circular knitting machines have been equipped with so called half-gauging patterning systems. Such a system is necessary when the number of feeds around the cylinder limits the diameter of the rotary patterning units to such an extent that it is not readily possible to provide a radial tooth position in each plane for every patterning butt. In half-gauging alternate patterning butts are at one height, while intervening butts are at a slightly different height; the radial teeth are arranged in pairs in superimposed planes around the patterning units. The upper and lower of each pair are so relatively arranged as to act on the upper and lower butts of the respective needles. Thus the pitch, or gauge, of the teeth in each plane can be coarser than the pitch, or gauge, of the patterning butts.

Each of the rotary units has actually consisted of a stack of superimposed discs each having at its periphery a circumferential series of prearranged radially extending teeth. Thus for half-gauging it has merely been necessary to slightly angularly offset alternate discs of each stack in order to achieve the desired arrangement of the teeth.

One aim of the present invention is to obviate the necessity to employ stacks of superimposed discs having at their peripheries prearranged radially extending teeth for action on the single patterning butts on the presser jacks.

A particular aim of the invention is to provide an improvement in a patterning system to enable wider pattern areas than heretofore to be produced on a multifeed circular knitting machine having a given number of feeds which is large in relation to the cylinder diameter.

According to the present invention each rotary patterning unit is a patterning system of the character concerned equipped for half-gauging consists of a rotary drum provided with teeth which protrude from its surface, the single patterning butts on the presser jacks are provided at a plurality of heightwise positions coincident with superimposed planes occupied by a corresponding number of coadjacent circumferential series of teeth on each rotary pattern drum and are regularly arranged around the cylinder in repeating series each of the same number of successive groups equivalent in number to half the number of heightwise positions, the butts in each group encompassing a circumferential distance around the cylinder equivalent to that covered by a rotary drum as it revolves one complete revolution during relative rotation between the cylinder and its cam box and being arranged alternately along two spaced-apart planes corresponding in their spacing with half the total overall height of the planes of teeth on the patterning drums.

Thus, in this arrangement each patterning unit consists of a rotary drum provided with teeth. Such a unit is simpler to construct than a unit comprising superimposed toothed discs. Furthermore, by relatively widely separating the planes on which alternate patterning butts are arranged, setting of a pattern, by, e.g., removing selected teeth, is greatly simplified. Thus the pattern is set in two distinct halves corresponding with the upper and lower parts of the drum and the wider spacing of the teeth on the drum which results from this separation of the pattern halves greatly reduces the dangers of removing a wrong tooth.

Each drum is intended to be vertically disposed, and is driven in precisely the same manner and from the same source as are the rotary stacks of discs heretofore provided. That is to say, each drum may conveniently have, rigid therewith, a shaft the lower end of which extends well below the drum and is mounted for rotation in one or more bearings provided on a suitable bracket, the lower extremity of the said shaft being furnished with a pinion arranged in mesh either with the cylinder or the cam box driving gear, as the case may be, or with an associated gear. The single patterning butts on the presser jacks are also disposed in a similar way as before, and the teeth with which each drum is furnished correspond to the peripheral teeth on the discs previously provided.

It is within the broad scope of the invention that each drum shall, if desired, be made with integral teeth. In such a case there would initially be full complements of the integral teeth in the respective superimposed planes, predetermined ones of the teeth in each plane being broken off, according to requirements.

Preferably, however, each drum has formed therein a circumferential series of parallel, axially extending tricks or grooves in which are accommodated inserts furnished with the teeth. Each drum insert may be initially formed along its length with a full complement of frangible teeth (corresponding in number to the total number of superimposed planes of teeth), those teeth which are not required being broken off. This construction of drum is, in practice, simpler to manufacture.

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

FIG. 1 is a vertical sectional view of so much of the head of a circular knitting machine of the rotary needle cylinder type equipped with a needle-actuating jack system as is necessary to illustrate the application thereto of a rotary patterning drum provided with teeth in superimposed planes for action upon single patterning butts on presser jacks included in the said jack system,

FIG. 2 is a detail vertical sectional view corresponding to the upper part of FIG. 1 showing a needle being raised by a needle-actuating jack,

FIG. 3 is a further detail vertical sectional view depicting the manner in which the needle-actuating jacks and hence also the intermediate swiveling jacks and the presser jacks are cam actuated in readiness for reselection,

FIG. 4 is a vertical sectional view similar to FIG. I but showing an alternative, and preferred, jack system wherein the action of pressing in a presser jack causes the corresponding needle to miss-knit,

FIG. 5 is a further detail sectional view corresponding to the upper part of FIG. 4 showing how in this case the intermediate swiveling jacks are acted upon by a withdrawal cam which suitable positions the said jacks for reselection,

FIG. 6 is a diagram showing four different forms of presser jacks for use in carrying out half-gauging,

FIG. 7 is a diagram illustrating a particular presser jack patterning butt layout using presser jacks of the four forms set out in panels,

FIG. 8 is a perspective view depicting a tricked or grooved rotary drum, comprising initially separate upper and lower sections, suitable for operating in conjunction with the butt layout shown in FIG. 7 in carrying out half-gauging,

FIG. 9 is a diagram of numbered teeth-containing planes facilitating the description of one particular sequence of shifting presser jacks upwards and downwards,

FIG. 10 is a perspective view of another form of tricked or grooved rotary drum made in one piece with the tricks or grooves extending in line from end to end thereof and showing also a drum insert with frangible teeth offset both to the right and to the left,

FIG. 11 is a presser jack patterning butt layout in respect of jacks having common height selection butts and in conjunction with which the drum shown in FIG. 10 can operate,

FIG. 12 is a further perspective view of a tricked or grooved rotary drum like that shown in FIG. 10 but having therein a drum insert with a different arrangement of offset teeth hereinafter to be described,

FIG. 13 is another presser jack patterning butt layout in respect of jacks having common height selection butts and in conjunction with which the drum shown in FIG. 12 can operate,

FIG. 14 is a detail plan view including a few presser jacks shown in relation to a rotary drum furnished with inserts having teeth offset both to the left and right,

FIG. 15 is a detail perspective view of presser jacks having single patterning butts offset to left and right,

FIG. 16 illustrates a bank of bolt cams constituting the variable presser jack positioning means for action on the common height selection butts shown in FIGS. 11 and I3 for the purpose of lifting and lowering jacks in any desired sequence or for bluffing such jacks at any predetermined height,

FIG. 17 is a detail cross section, taken on the line XVII XVII of FIG. 16, of an annulus formed with horizontal buttlocating grooves,

FIG. 18-21 are diagrams illustrating how the bolt cams are mounted upon slides and associated one with another, the four views illustrating respectively different operational sequences brought about by certain of the said cams being moved to their in" positions,

FIGS. 22A and 2213 together constitute a sequence diagram illustrating the operation of the bolt cams for producing a nonmirror repeat design of full depth,

FIG. 23 is a similar sequence diagram illustrating the operation of the bolt cams for producing a smaller nonmirror repeat design using an even number of pairs of drum insert teeth,

FIG. 24 is a view similar to FIG. 23 but showing a sequence of bolt cam operations for producing a smaller nonmirror repeat design using an odd number of pairs of drum insert teeth,

FIGS. 25A and 25B together illustrate a further sequence of bolt cam operation for producing mirror-repeat designs,

FIG. 26 depicts bolt cam settings to allow presser jacks to remain at any selected height for elongated patterns, and

FIG. 27 diagrammatically illustrates how information is read from a rotary drum, using one pair of drum insert teeth in both the bottom half and in the top half of the drum at a time,

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

Referring to FIG. 1, the rotary needle cylinder of the illustrated multifeed circular knitting machine is indicated at 50. This cylinder has formed therein a circular series of axially extending tricks or grooves such as 51 in the upper end of each of which is accommodated an individually slidable latch needle 52. Each such needle is furnished with an operating butt 53 adapted to be acted upon by needle-operating and controlling cams, such as 54 and 55, mounted in a stationary annular cam box 56 surrounding the rotary needle cylinder 50.

The base of the knitting head is indicated at 57 and the cylinder drive gear at 58.

Immediately beneath each needle 52 there is provided a needle-actuating jack 59 which is fulcrummed at 59a, i.e., at its upper end. In the lower end of each needle trick or groove 51 is mounted a presser jack such as 60 (FIG. 1) which is fulcrummed at its lower end 60a and has on the front of its stern a single patterning butt 61. The lower portion of the stern of each presserjack 60 is formed with six equally spaced and outwardly directed height selection butts 62. Between each needle-actuating jack 59 and the corresponding presser jack 60 there is provided, in the same trick or groove 51, an intermediate swiveling jack 63 which is fixed as regards any movement heightwise. The particular presser jack 60 shown is one of four different forms of such jack provided in the machine as and for the purpose hereinafter to be described. In any event, and whatever its form may be, each presser jack is arranged in front of the corresponding swiveling jack 63. The swiveling jacks 63 are fulcrummed at points between their upper and lower ends so that whenever a presser jack 60 is pressed in, the lower end 63a of the corresponding swiveling jack will also be swung inwardly to the back of the relevant cylinder trick or groove 51: as a consequence, and as shown in FIG. 1, the upper end 63b of this same swiveling jack will be swung outwardly and, since it is in direct contact with the back edge of the corresponding needle-actuating jack 59, will cause the latter also to be swung outwardly to project an operating butt 59b thereon into a jack camming track 65 in the stationary cam box 56. In this way, the selected needle-actuating jack 59 and hence also the associated needle 52 are raised by the jack camming as shown in FIG. 2. Conversely, and after this selective action has taken place, a cam 66 depicted in FIG. 3 acts on the front edge of the needle-actuating jack 59 near its lower end and pushes the said jack inwardly to withdraw its operating butt 59b from the jack camming track 65. The result of this is to press the upper end 63b of the corresponding swiveling jack 63 inwards and swing its lower end 630 outwards, thereby returning the presser jack 60 into its original outward position in readiness for reselection.

The machine is provided, in advance of each feed, with a rotary patterning, i.e., selector, drum 67 presenting circumferential series of radial teeth 68 in superimposed horizontal planes for action on the single patterning butts 61 of the presser jacks 60. Thus, each presser jack 60 is selected and subsequently reselected by teeth 68 presented in the appropriate planes by the rotary patterning drums. Each drum 67, in this example, has formed therein a circumferential series of equally spaced and axially extending parallel tricks or grooves in which are accommodated inserts 69 furnished with the teeth 68. Each drum 67, moreover, has rigid therewith a shaft 70 the lower end of which extends well below the drum and is mounted for rotation in vertically spaced

bearings

71 and 72 provided in a bracket 73. This is supported in a rebated portion of the knitting head base 57. The lower extremity of the shaft 70 has secured thereto a pinion 76 arranged in mesh with a gear 77 which is rigidly attached, by screws 78, to the lower end of the needle cylinder 50. The gear 77 is, in fact, interposed between the said cylinder and its drive gear 58.

Thus, in the jack system just described with reference to FIGS. 1-3, the pressing in ofa presserjack 60, by the action of a tooth 68 upon its single patterning butt 61, causes the corresponding needle 52 to knit. However, the exact opposite may be, and preferably is, the case, i.e., the action of pressing in a presser jack 60 will cause the corresponding needle 52 to miss-knit.

In this preferred system, illustrated in FIGS. 4 and 5, the intermediate swiveling jackin this case designated 79-is fulcrummed at 80 at its lower end, so that whenever a presser jack 60, located in front of the swivelingjack, is pressed in, the upper end 79a of the swiveling jack 79 will also be swung inwards. The said upper end 79a is in the form ofa two-pronged fork, the tail 590 of the needle-actuating jack 59 being located between the two prongs. Thus, the inward movement -of the swiveling jack 79 will also cause the needle-actuating jack 59 to swing inwards and to withdraw its operating butt 59b from the jack camming track 65 thus causing its associated needle 52 to miss-knit. It follows that the needles associated with unselected jacks will knit. There is, in this example, also formed on the top of the swiveling jack 79 an upwardly projecting butt 79b, and in advance of each feed, just prior to the selector drum 67, there is provided a withdrawal cam 81 (see FIG. 5). The action of this cam 81 on the upwardly projecting butts 79b is to restore those jacks 79 which were previously selected and pressed in to their outer position in readiness for reselection. Those jacks not selected will remain in the outer position. Since the tail 59c ofa needle-actuating jack 59 is located in the forked end 79a of the corresponding swiveling jack 79, the outward movement of the latter will also cause the needleactuating jack to move outwards thus bringing its operating butt 59b back into the jack camming track 65.

In another among other possible alternative systems, the elements to be controlled or influenced are again in the form of needle-actuating jacks placed beneath needles, but in this instance the jacks are provided with downwardly extending spring extensions which, whenever permitted to do so, move outwardly under the spring influence but are capable of being pressed back by the rotary patterning drums 67 into the relevant tricks or grooves 51 by the corresponding presser jacks 60. Thus, in this alternative example (not shown), whenever the springy extension of a needle-actuating jack moves outwardly, a lower butt thereon engages with a jack-raising cam whereby the jack and hence also the corresponding needle is raised. On the other hand, a jack extension selectively pressed inwards to miss the cam remains down.

Merely for convenience in the following further description the latter will be based, as earlier, on a pattern width of I44 needles without, however, any limitation in this respect.

In one specific half-gauging arrangement, the first of the four different forms of presser jacks 60 required has a single patterning butt 61 at a heightwise position (a), the second with a patterning butt at a slightly higher heightwise position (b), the heightwise space between the positions (a) and (b) being equal to the space between any two adjacent planes of insert teeth 68 on a rotary drum 67, and the third and the fourth with single patterning butts 61 respectively at lower and higher positions (c) and (d) well spaced above the positions (a) and (b). The heightwise space between positions (c) and (d) is the same as between the positions (a) and (b) all as diagrammatically depicted in FIG. 6. The presser jacks of all these four forms, however, unlike the presser jacks shown in FIGS. 1 and 4, have similar height selection butts 82 adapted to be acted upon by variable presser jack moving means for shifting the presser jacks upwards and downwards to varying desired extents to dispose their single patterning butts 61 opposite to teeth 68 in the relevant planes. For each successive repeating series or panel of I44 needles around the needle cylinder 50 of the machine, there are, of course, the same number of presser jacks 60one per needle 52. Of the presser jacks corresponding to the first 72 needles of the said panel (a few of which jacks are bracketed together at E in FIG, 7), the alternate ones have their single patterning butts 61 at height (a) whereas the intervening ones have their patterning butts 61 at height (c). On the other hand, the single patterning butts 61 of the presser jacks corresponding to the remaining 72 needles of the same panel (a few of which jacks are bracketed together at F) alternate at heights (b) and (d). For diagrammatic purposes, the single patterning butts 61 in FIG. 7 are represented as solid black dots.

Each of the tricked or grooved rotary drums provided to operate in conjunction with the presser jack patterning butt layout shown in FIG. 7 may, as depicted in FIG, 8, comprises initially separate upper and lower sections 670 and 67b which are rigidly secured together to rotate together as a single drum 67. These sections 67a and 67b are coaxial and both of the same axial extent, i.e., height. Thirty-six equally spaced tricks or grooves are formed in and around each of these two sections, the tricks or grooves 67c in the upper section 67a being circumferentially offset in a half-gauge relationship with respect to those tricks or grooves 67d in the lower section 67b. In their initial form the inserts accommodated in all 72 tricks or grooves of the sectional drum 67 are identical. Predetermined ones of the insert teeth are, however, broken away according to patterning requirements. The teeth left protruding radially from each of the upper and lower sections 670 and 67b of each rotary drum 67 are disposed in 24 superimposed horizontal planes. The planes of teeth in the lower drum section 67b are arranged in pairs in an AB, AB, AB relationship to correspond with the patterning butt heights (a) and (b), whereas the corresponding 24 planes of teeth in the upper drum section 67a are similarly arranged in pairs in a CD, CD, CD relationship to correspond with the patterning butt heights (c) and (d). The predetermined dispositions of teeth left on the inserts in the various horizontal planes vary as between one plane and another according to the pattern.

Thus, as will be readily appreciated, teeth on drum inserts accommodated in the lower section 67b of each rotary drum 67 are for action upon patterning butts 61 at heights (a) and (b), while teeth on inserts in the upper drum section 670 are for action upon patterning butts 61 at heights (c) and (d).

Referring to FIG. 9 it will now be assumed that, starting from the bottom of the lower drum section 67b and proceeding to the top thereof, the horizontal insert teeth-containing planes are numbered 1-24, the AB pairs of such planes accordingly being numbered 1 and 2,3 and 4, 5 and 6, 7 and 8, 9 and 10, 11 and 12, and so on. It will also be assumed that, starting from the bottom of the upper drum section 67a and proceeding to the top thereof, the teeth planes are numbered 25-48, the CD pairs of planes thus being numbered 25 and 26, 27 and 28, 29 and 30, 31 and 32, 33 and 34, 35 and 36, and so on. In such a case, with all the presser jacks 60 in their fully lowered positions, the patterning butts 61 at heights (a) and (b) will be opposite to the

pair

1 and 2 of AB planes of insert teeth, whereas the patterning butts at heights (c) and (d) will be opposite to the pair 25 and 26 of CD planes of insert teeth. This particular relationship can be sequentially changed from time to time by the variable presser jack moving means provided for shifting presser jacks 60 upwards and downwards to dispose the groups of patterning butts 61 at the aforementioned different heightwise positions opposite to predetermined pairs of teeth planes.

The variable presser jack shifting means operate once per revolution of the needle cylinder 50 (in a gap where presser jacks 60, needle-actuating jacks S9 and needles 52 are left out of the cylinder).

One particular operational sequence, quoted merely by way of example, will now be described with reference to FIG. 9. Start:

Teeth planes numbered 1 and 2 and 25 and 26 select the first 144 needles of pattern. Next, the presser jacks 60 are raised so that the pattern butts 61 at (a) are opposite teeth plane No. 5 of the AB group, those at (b) are opposite teeth plane No. 6 of the same group, those at (c) are opposite plane No. 29 and those at (d) are opposite plane 30, both such planes being in the CD group, these conditions being maintained for one complete revolution of the needle cylinder 50.

Then the presser jacks 60 are again lifted so that, throughout the next revolution butts at (a) are opposite plane No. 9 butts at (b) are opposite plane No. 10, those at (c) opposite No. 33 and those at (d) opposite No. 34, and so on until (a) butts are level with plane 23, (b) butts with plane 24, (c) butts with plane 47 and (d) butts with plane 48, this completing half the pattern depth.

Thereupon, the presser jacks 60 are lowered so that, during the next revolution of the cylinder 50, (a)s are level with 19, (b)s with 20, (c)s with 43 and (d)s with 44. The presser jacks are then lowered again so that throughout the next revolution (a)s are level with 15, (b)s with 16, (c)s with 39, and (d)s with 40, and so on until the original conditions are restored, one pattern having been completed in readiness to start the next. In FIG. 9, planes with teeth acting on such jacks in the course of being moved downwardly are represented by dotted lines.

It is to be clearly understood that the sequences of up and down movements of the presser jacks are capable of practically infinite variation.

The aspect of the invention last described could, if desired, be extended, in appropriate conditions, to achieve triple gauging with rotary drums each built in three coaxial sections-and so on.

While it is practicable to manufacture a drum in two sections with the upper section offset relatively to the lower section to facilitate half-gauging and to keep the inserts standard, it nevertheless has to be realized that such a construction involves the use of comparatively large numbers of inserts. Accordingly, it will generally be preferred to manufac ture each drum in one piece with the tricks or grooves extending in line from end to end thereof, and to adopt an arrangement in which there is only one insert 69 (FIGS. 1 and 4) for every two presser jacks 60 (and hence also for every two needles 52 since in this preferred case, assuming the single patterning butts 61 on the said jacks are set out at four heights (a), (b), (c), and (d) as hereinbefore described, it is possible to retain the benefits of half-gauging using only half the quantity of drum inserts.

This can be achieved in one of two alternative ways. The first way, generally illustrated in FIGS. 10 and 12 is by initially forming each drum insert 69 along its length with a full complement of frangible teeth half of which teeth, designated 68R, are offset to the right while the other half, designated 68L are offset to the left. The teeth may be offset alternately to the right and left as shown in FIG. 12, the teeth offset to the right being capable of acting upon presser jack patterning butts 61 at heightwise position (a) or (c), FIG. 23, and the teeth offset to the left being similarly capable of acting upon patterning butts at heightwise positions (b) or (d), as the case may be. Alternatively the teeth in the lower half of the drum may be offset to one side while those in the upper half are offset to the other side; such an arrangement is shown in FIG. 10, the teeth 68R in the lower half of the drum being offset to the right and being capable of acting upon pressure jack patterning butts 61 at heightwise positions (a) or (b), FIG. 11, the remaining teeth 68L offset to the left being capable of acting upon patterning butts at heightwise positions (c) or (d).

The second way, producing the same result, is to employ flat drum inserts but to offset the single patterning butts 61 of the alternate and intervening presser jacks respectively to the right and left as shown in FIG. 15. In both arrangements the stern of each drum insert is lined up between two cylinder tricks 51.

Based on the same figures as in previous examples, each single-piece rotary drum 67 may have 36 equally spaced tricks or grooves 67c to receive inserts each initially having along its length 48 teeth; thus, in the case where insert teeth are offset, the lower 24 teeth 68R may extend to the right and the upper 24 teeth 68R may extend to the right and the upper 24 teeth 68L to the left of the central stem of each insert 69 (as shown in FIG. 10 or, to facilitate pattern reading. the initially full complement of 48 teeth on each insert may extend alternately to the right and to the left of the stem (as shown in FIG. 12).

Assuming that each drum 67 is equipped with drum inserts 69 each of a form initially having along its length 48 superimposed frangible teeth ofiset alternately to the right and left as just-described reference to FIG. 12, then for half-gauging in these circumstances, the presser jacks 60 corresponding to the first 72 needles of each repeating series or panel of 144 needles around the cylinder are comparatively short ones having at their upper ends single patterning butts 61 at heights (a) and (b) for cooperation with the bottom 12 pairs of planes of insert teeth presented by each rotary drum. The presser jacks corresponding to the second 72 needles of the said panel of 144 are longer ones having at their upper ends single patterning butts 61 at heights (c) and (d) for cooperation with the top 12 pairs of planes of insert teeth of each drum (see FIG. 13). The first 72 jacks of each panel of 144 are, in fact, arranged with the patterning butts 61 at heights (a) and (b) in alternating relation, the butts at height (b), however, being at a slightly higher heightwise position that the butts (a) and the heightwise space between (a) and (b) being equal to the space between any two adjacent planes of insert teeth. Similar remarks apply to the butts 61 at heightwise positions (c) and (d), i.e., they are in alternating relation, with butts at height (d) slightly higher than butts at height (c) and with the space between them equaling a space between any two planes of insert teeth.

Thus, in the example illustrated in FIGS. 12 and 13, information is read from each drum 67, using one pair of drum insert teeth 68 in the bottom half of the drum and another pair of drum insert teeth 68 in the top half as depicted in FIG. 27. The pairs of planes AB and CD containing drum insert teeth are to be regarded as being numbered upwards from 1 to 12 in each half of the drum. Different designs which can be produced, when using this particular system will be hereinafter described.

For half-gauging in conjunction with a drum 67 in which the lower 24 teeth 68R extend to the right and the upper 24 teeth 68L to the left, as hereinbefore described with reference to FIG. 10, the presser jacks 60 corresponding both to the first and to the second 72 needles of each repeating series or panel of 144 needles around the cylinder 50 are alternately short and long ones, the said short and long jacks of the first 72 having at their upper ends single patterning butts at heights (a) and (c) respectively, and the short and long jacks of the second 72 similarly having at their upper ends single patterning butts at heights (b) and ((1) respectively. The butts at height (b) are spaced above the butts at height (a), and the butts at height (d) are spaced above the butts at height (0) a short distance equal to the pitch of the insert teeth-containing planes.

The variable presser jack moving means for shifting presser jacks 60 upwards and downwards to dispose the groups of single patterning butts 61 at the aforementioned different heightwise positions opposite to the circumferential series of teeth in predetermined pairs of planes may, within the broad scope of the invention, consist of a height selection cam component (not shown) which is automatically movable up and down to varying desired extents, under the control of means operable once per revolution of the machine, and has formed in one side thereof a V-shaped notch adapted to provide, for action respectively upon upper and lower edges of single height selection butts e.g., 82, Fig. 6) provided on the presser jacks, downwardly and upwardly sloping cam edges both leading into a straight cam track portion.

The said cam component may be vertically movable up and down slidably within a slideway, or between suitable guides, and the desired movements of varying predetermined extents may be effected and controlled by an appropriately profiled rotary master cam through the medium of any suitable intermediate gearing.

However, the variable presser jack positioning means preferably comprise, as illustrated in FIG. 16, a bank of bolt carns operable to lift or lower the presser jacks 60 in any desired sequence-or to bluff the said jacks at any predetermined height, the said bolt cams being arranged for action upon predetermined ones of a plurality of height selection butts 62 on each presser jack (see FIGS. 11 and 13), and the presser jacks being retained in the heightwise positions to which they are either lifted or lowered by virtue of the relevant height selection butts being led and passing into horizontal butt-locating

grooves

85 and 86 formed in an annulus 87. This annulus is, of course, gapped as at 88 at the location at which the bolt cams (advantageously disposed one above another at different heights) are provided.

The specific arrangement of the bolt cams in relation to the fixed grooved annulus 87 and as applied to a machine such as that shown either in FIGS. l-3 or FIGS. 4 and will now be described. In this arrangement, the lower portion of the stem of each presser jack 60 is provided with six ofthe height selec tion butts 62 equally spaced apart one above the other. There is a bank of six bolt cams arranged one above the other, these cams, reading from the upper one downwards, comprising a cam Z adapted to lower presser jacks one pitch, a cam X adapted to lift jacks one pitch, a cam Y for lowering jacks two pitches, a cam W for lifting jacks two pitches and cams Z and X identical to the cams Z and X respectively. The needle cylinder 50 is assumed to rotate anticlockwise so that, on the diagram depicting the bolt cams, the presser jacks 69 travel from right to left (FIG. 16). Bearing this in mind, each of the bolt cams adapted to lift jacks will have an upwardly inclined edge for action upon the lower edges of height selection butts 62, whereas each bolt cam adapted to lower jacks will have a downwardly inclined edge for action upon the upper edges of such height selection butts. The fixed annulus 87, having therein a gap 88 ofa circumferential extent equal to the length of the bolt cams, is formed with two horizontal grooves. The top of the upper groove 85 is coincident with the lowest point of the cam Y, and the bottom of the lower groove 86 is coincident with the highest point of the cam W.

Selective operation of these cams can, therefore, produce both single and double lifting or lowering movements of the presser jacks 60, or any desired combination of such.movementsincluding bluffing" as a result of which presser jacks pass through at the same height. It is accordingly possible to produce:

i. Nonmirror designs of any desired depth, within the limits of the system, and which can be varied by using all, or any lesser number, of the insert teeth, as may be desired.

ii. Mirror repeat designs (in depth) which can also be varied as in (i) above.

iii. Elongated patterns by bluffing the presser jacks at any selected height.

Bluffing at any stage of a design can thus result in economy in the preparation of drum inserts for comparatively large depth patterns.

The bolt cams are mounted upon slides each of which is movable to one of three positions, viz, an out" position 89, an in" position 90 and an intermediate neutral position 91 (see FIGS. 18-21). It is an essential requirement that it shall be impossible to have cams with differing actions in operation at any one time. Thus, the cams X and X are linked and operate together. This also applies to the two cams Z and Z. The

slides

92 and 93 of cams X and Z, and also the

slides

94 and 95 of cams X and Z have a pinion 96 interposed between them meshing with opposed series of

rack teeth

97 and 98 on said slides. The

slides

99 and 100 of cams Y and W also have a pinion 101 interposed between them meshing with

opposed rack teeth

102 and 103 on the slides. Moreover, each of the

slides

92, 94, 93 and 95 of the four bolt cams X, X and Z, Z are provided with two spaced

pins

104 and 105. Between the two pairs of pins provided on the

slides

92 and 93 of cams X and Z is an arm 106 extending from the slides 99 of cam Y. Similarly, an arm 107 extending from the slide 100 of cam W, is located between the two pairs of

pins

104, 105 on the

slides

94 and 95 of cams X and Z. Interaction between the pinions 96 and the

racks

97 and 98 and between the

arms

106, 107 and the

pins

104, 105 ensures that it is impossible to have cams with differing actions in operation together.

This is illustrated in the sequences diagrammatically shown in FIGS. 182l. Only when cams are in the fully in position can they operate on relevant height selection butts 62 of the presser jacks.

Thus, FIG. 18 shows the conditions which exist when the bolt cam W is in its fully in position as will be seen rotation of the pinion 101 between the

slides

99 and 100 of cams Y and W has ensured that the cam Y is in its fully out position 89. The

arms

106 and 107 on the

slides

99 and 100 of the bolt cams Y and W have acted on

pins

105 and 104 respectively to move the cams X and Z and X and Z all to the neutral position.

In FIG. 19, the two bolt cams X and X are both in their in" positions 90. The pinions 96 have moved the slides 93 and 9S suchwise as to withdraw both of the bolt cams Z and Z to their fully out positions 89. The pin 105 on the slide 92 of the cam X has acted upon the arm 106 to appropriately move the slide 99 to the extent and in the direction necessary to locate the cam Y in the neutral" position 91. The pinion 101 between the

slides

99 and 100 has turned to move the slide 100 to the extent of also positioning the cam W in its neutral position.

FIG. 20 depicts the conditions which exist when the cam Y is in its in position 90. The pinion 101 has this time moved the cam W to its fully out position 89. The arm 106 on the slide 99 has contracted the pin 104 on the slide 93 to move the cam Z to its neutral position 91. The top pinion 96 has suitably moved the slide 92 to dispose the cam X in its neutral position. The arm 107 on the slide 100 has contacted the pin 105 on the slide 94 and shifted the latter to dispose the cam X in its neutral position 91, and the bottom pinion 96 has burned to displace the slide to such an extent as to locate the cam Z also in its neutral" position.

As to FIG. 21, this shows both of the bolt cams Z and Z in their fully in positions. In this sequence, both of the pinions 96 have turned to move both of the cams X and X to their fully out" positions 89. The pin 104 on the slide 92 of the cam X has acted upon the arm 106 and thereby moved the slide 99 suchwise as to dispose the cam Y in its neutral position. The pinion 101 has also turned to move the slide to the extent and in the direction necessary to locate its cam W in the neutral position.

The specific manner in which the various bolt cams Z, X, Y, W, Z and X operate to lift and lower the presser jacks 60 relatively to the rotary drums 67 or 67 will now be described with reference to FIGS. 22A26. In each of these figures, the direction of travel of the said presser jacks relatively to the stationary bolt cams is from right to left.

FIGS. 22A and 228 show the bolt cam operation requirements for a nonmirror repeat design of full length. Thus, starting from the right-hand side of FIG. 22A and progressing to the left-hand side of FIG. 22B (and regarding the pairs of planes AB and CD containing drum insert teeth 68 to be numbered upwards from 112 in each half of a drum), it will be appreciated that it is necessary first to lift the presser jacks 60 two pitches at a time by the bolt cam W and to act selectively upon the single patterning butts 61 by insert teeth in the oddnumbered pairs of planes, and them to lower the same jacks in two pitch stages by the bolt cam Y and so cause their single patterning butts to be acted upon by insert teeth 68 in the even pairs of insert-teeth-containing planes. More specifically, and bearing in mind that in the illustrated example there is only one group of bolt cams, it will be appreciated that in FIGS. 22A and 228 the cam W is shown in its in" position during five successive revolutions of the machine and at the sixth revolution the cam W is out" and the cams X and X is in and at the 12th machine revolution the cam Y is moved out" and the cams Z and Z in." The description will now be concentrated, by way of example, on the single patterning butts 61 of the presser jacks which read the pairs of AB planes, i.e., the 12 pairs of such planes in the lower half of each rotary patterning drum 67. Thus, at the first stage, i.e., starting position, at the extreme right of FIG. 22A, the single patterning butt 61 of each relevant presser jack is reading from No. 1 pair of planes AB of insert teeth, and the second height selection butt 62 down on each such presser jack 60 is about to be acted upon by the bolt cam W which will lift the jack two pitches. At the second stage leftwards, the butt 61 is reading from No. 3 pair of insert-teeth-containing planes and the third height selection butt down is about to be acted upon by the cam W whereby the jack will At lifted a further two pitches. At the third stage, the butt 61 is reading from N0. 5 pair of planes AB and the fourth height selection butt 62 down is about to be acted upon by the cam W with the same result. At the fourth stage, the butt 61 is reading from No. 7 pair of teeth-containing planes AB and the fifth height selection butt is about to be acted upon by cam W. At the fifth stage, butt 61 is reading from No. 9 pair of planes and the bottom height selection butt 62 is about to be acted upon by the cam W which thereupon acts to lift the presser jack two pitches for the fifth time from the start. Next, the cam W is moved out and the cams X and X in so that at the sixth stage, with the patterning butt 6] reading No. 11 pair of planes AB, the fourth height selection butt down is about to be acted upon by the cam X which acts to lift the presser jack to the extent one pitch only. This enables the fifth height selection butt down to be acted upon by the cam X to depress the presser jack to the extent of two pitches for the first time at the termination of the seventh stage during which the single patterning butt 61 reads from No. 12 pair of teeth-containing planes AB. At the eight stage, the butt 61 is reading from No. 10 pair of such planes, and the fourth height selection butt down is about to be acted upon the cam Y by means of which the presser jack will be moved down to the extent of two pitches for the second time. At the ninth stage, i.e., ninth revolution of the machine, the patterning butt 61 is reading from No. 8 pair of teeth-containing plane and the third height selection butt down is about to be acted upon by the cam Y which will depress the jack to the extent of two pitches for the third time. Then at the 10th stage, the butt 61 is reading No. 6 pair of planes AB and the second height selection butt down is about to be acted upon by the same cam Y which will thereupon function to depress the presser jack two pitches for the fourth time. Next, at the 11th revolution of the machine, the patterning butt reads from No. 4 pair of planes and the top height selection butt 62 is about to be acted upon the cam Y which moves the presser jack down two pitches for the fifth and last time. Finally, at the 12th stage the butt 61 reads from No. 2 pair of AB planes, and the third height selection butt down is about to be acted by the bolt cam Z which functions to move the presser jack down to the extent of one pitch so that the said jack is again in the starting position shown at the extreme right-hand side of FIG. 22A.

FIG. 23 shows the bolt cam operation requirements for producing a smaller depth nonmirror repeat design using an even number of pairs of drum insert-teeth-containing planes. The example shown uses, in fact, only six pairs of such planes.

To increase or decrease the number of planes used, bolt cams W AND Y are respectively operated a greater or less number of times. With the full description of the combined FIGS. 22A and 223 in mind, it will be possible for the reader readily to follow FIG. 23 along similar lines with only a minimum of description. Thus, starting from the right of FIG. 23 and proceeding leftwards, the single patterning butt 61 reads at the first stage (i.e., start) from No. 1 pair of planes, from No. 3 pair of planes at the second stage; No. 5 at the third stage; No. 6 at the fourth stage; No. 4 at the fifth stage and No. 2 at the sixth stage-preparatory to No. 1 again at the starting position shown at the extreme left hand side of FIG. 23. Meanwhile, the cam W raises the presser jacks to the extent of two pitches twice; then the cam X raises such jacks one pitch; next the cam Y depresses the jacks to the extent of two pitches twice, and finally the cam Z depresses the jacks one pitch.

A procedure for producing a small depth nonmirror repeat design using an odd number of pairs of insert-teeth-containing planes is shown in FIG. 11$. This further example shows the use of five pair of planes. To increase or decrease the number used, the cams W and Y are respectively operated a greater or less number of times. Viewing FIG. 24 from right to left: the single patterning butt 61 at the first stage (start) reads from No. 1 pair of planes; from No. 3 pair of planes at the second stage; from No. 5 at the third stage; from No. 4 at the fourth stage, and from No. 2 t the fifth stage-preparatory to the presser jack 60 resuming its starting position shown at the extreme left of the FIG. Meanwhile, the cam W, by action upon appropriate height selection butts 62, lifts the presser jacks two pitches twice; the two-pitch cam Y thereafter LOwers the jacks first to the extent of one pitch only and then to the extent of two pitches; finally, the cam Z lowers the iacks one pitch.

FIGS. 25A and 2513, considered together, illustrates a typical cam set-out for producing mirror-repeat designs. Only five pairs of teeth-containing planes are used, although this number can be increased or decreased by operating bolt cams X and W (for liftingjacks) and bolt cams Y and Z (for lowering jacks) a greater or less number of times. The cams Z and X are utilized whenever presser jacks are lifted to a higher elevation than is shown in FIGS. 25A AND B. It is also to be noted that both of the two-pitch cams W and Y are employed to move the presser jacks to the extent of one pitch only.

Viewing first FIG. 25A and then FIG. 25B from right to left, the single patterning butt 61 for each relevant presser jack 60 reads No. 1 pair of planes at the first stage (start); No. 2 pair of planes at the second stage; No. 3 pair of planes at the third stage; No. 4 at the fourth stage; No. 5 at the fifth stage; and No. 2 at the eighth stagepreparatory to the present jack being restored to its starting position where the butt 61 against reads No. 1 pair of planes, and so on. Meantime, the bolt cam X first lifts the presser jack one pitch then the two-pitch cam W lifts the jack one pitch; next, first the cam X and then the cam W against which lifts the jack one pitch; thereafter the said jack is depressed four times each to the extent of one pitch respectively by the cam Y, the cam Z, the cam Y and the cam Z in that order by which time the presser jack is again at its staring position.

The bolt cam settings to allow presser jacks 60 to remain at any selected height, for elongated patterns, are depicted in FIG. 26. As will be seen in this figure the cams X and X and Z and Z prevent presser jacks falling and also ensure that height selection butts 62 are fed accurately into the grooved annulus 87.

At the left-hand side of FIG. 26 the two cams X and X are shown "in" with the presser jacks (whose patterning butts 61 are reading from any even-numbered pair of drum insertteeth-containing planes) passing straight through the cam system without being either lifted or lowered. At the righthand side of the same figure the two cams Z and Z are "in with the presser jacks (whose butts 61 are this time reading from any odd-numbered pair of planes) passing straight through the system.

Claims

2. A multifeed circular knitting machine according to claim 1, wherein each rotary patterning drum has formed therein a circumferential series of parallel axially extending tricks, and there are accommodated in said tricks inserts furnished with the teeth.
3. A multifeed circular knitting machine according to claim 1, wherein there are four different forms of presser jacks viz, the first form having a single patterning butt at a heightwise position (a), the second form with a patterning butt at a slightly higher heightwise position, (b), the heightwise space between the position (a) and (b) being equal to the space between two adjacent planes AB of insert teeth on a rotary drum, and the third and fourth forms of presser jacks having single patterning butts respectively at lower and higher positions (c) and (d) spaced above the positions A) and (b) respectively b y an amount corresponding with half the overall height of the planes of teeth on the patterning drums, the heightwise space between positions C) and (d) being the same as the positions (a) and (b) and between two adjacent planes CD of insert teeth on a rotary drum, the groups of presser jacks patterning butts being arranged around the machine in association with stitch-forming needles requiring to be controlled for producing patterning effects and wherein for each successive repeating series of needles around the needle cylinder there are the same number of presser jacks of which alteRnate one of those corresponding to the first half of the needles of the said repeating series have their patterning butts at height (a) whereas the intervening have their patterning butts at height (c), and the single patterning butts of the presser jacks corresponding to the remaining half of the needles of the same panel alternate at heights (b( and D).
4. A multifeed circular knitting machine according to claim 2, wherein each of the rotary drums is tricked to receive inserts each initially formed with a full complement of superimposed and radially protruding teeth any of which are capable of being broken off, said drum comprising initially separate upper and lower sections of the same axial extent, which sections are rigidly secured together, the tricks in the upper section being circumferentially offset in a half-gauge relationship with respect to those in the lower section, and the inserts in their initial form, i.e., before teeth are broken off, all being identical and standard.
5. A multifeed circular knitting machine according to claim 3, wherein each rotary patterning drum is in one piece, with the tricks extending from end to end thereof, and there is only one insert for every two presser jacks, the said inserts being wholly flat, with each lined up between two needle cylinder tricks, and the single patterning butts of the alternate and intervening presser jacks being offset respectively to the right and left.
6. A multifeed circular knitting machine according to claim 3, the cylinder of which is equipped with stitch-forming needles requiring to be controlled for producing patterning effects, and wherein before any teeth are broken off, each drum insert has all of the lower half of its teeth extending in one direction and all of the remaining upper half of such teeth extending in the opposite direction, and the presser jacks corresponding both to the first and to the second half of the needles of each repeating series, around the cylinder are alternately short and long ones, the said short and long jacks of the first half of the latter having at their upper ends single patterning butts at heights (a) and (c) respectively, and the short and long jacks of the second half of the same having at their upper ends single patterning butts at heights (b) and (d) respectively, the butts at heights (a) and (b) and (c) and (d) cooperating with pairs of planes AB and CD of insert teeth in the lower and upper portions of each rotary drum respectively.
7. A multifeed circular knitting machine according to claim 1, wherein each of the presser jacks is furnished with an equal number of superimposed height selection butts, and the machine includes a bank of bolt cams operable selectively on the said height selection butts to lift or lower presser jacks in any desired sequence or to retain such jacks at any predetermined height to dispose their single patterning butts opposite to teeth in predetermined planes; and an annulus having therein horizontal butt-locating grooves into which relevant height selection butts are passed to retain presser jacks in the heightwise positions to which they are lifted or lowered.
8. A multifeed circular knitting machine according to claim 7, wherein the lower portion of the stem of each presser jack is provided with six height selection butts equally spaced apart one above the other, and there is a bank of six bolt cams comprising a cam (Z) adapted to lower presser jacks one pitch, a cam (X) adapted to lift jacks one pitch, a cam (Y) for lowering jacks two pitches, a cam (W) for lifting jacks two pitches and two cams (Z1 and X1) identical to the aforesaid one-pitch lifting and lowering cams (Z and X) respectively, the various cams being selectively operable to produce both single and double lifting or lowering movements of the presser jacks as well as ''''bluffing'''' as a result of which jacks are caused to pass straight through the cam system at the same height.
9. A multifeed circular kNitting machine according to claim 7, wherein the bolts cams are mounted upon slides each of which is movable to one of three positions, viz, in, out or neutral, the cams (X) and (X1) being linked and operable together and the cams (Z) and (Z1) being similarly linked and operable together whereby it is impossible to have cams with differing actions in operation at any one time.
10. A multifeed circular knitting machine according to claim 9, wherein the slides of cams (X) and (Z) and also the slides of cams (X1) and (Z1) have a pinion interposed between them meshing with opposed series of rack teeth on said slides; the slides of cams (Y) and (W) also have a pinion interposed between them meshing with opposed rack teeth on the last-mentioned slides; each of the slides of the four cams (X, X1) and (Z, Z1) are provided with two spaced pins; between two pairs of pins on the slides of cams (X) and (Z) is an arm extending from the slide of cam (Y): and an arm extending from the slide of cam (W) is located between the two pairs of pins of the slides of cams (X1) and (Z1).