US3435637A

US3435637A - Straight-bar knitting machines

Info

Publication number: US3435637A
Application number: US617204A
Authority: US
Inventors: Reginald F Wholton; Clive Cartledge
Original assignee: TEXTILE MACHINERY DEV Ltd
Current assignee: TEXTILE MACHINERY DEV Ltd
Priority date: 1967-02-20
Filing date: 1967-02-20
Publication date: 1969-04-01
Anticipated expiration: 1986-04-01

Description

A ril 1, 1969 Filed Feb. 20, 1967 WHOLTON ET AL 3,435,637

STRAIGHT-BAR KNITTING MACHINES Sheet of 8 j Fig.1.

67* as 24 I 24 April 1, 1969 R. F. WHOLTON ET STRAIGHT-BAR KNITTING MACHINES Filed Feb. 20. 1967 Sheet L of 8 April 1, 1969 wHoLTo ET AL 3,435,637

STRAIGHT-BAR KNITTING. MACHINES Sheet Filed Feb. 20, 1967 Ap 1969 R; F. WHOLTON ET AL 3,435,637

STRAIGHT-BAR KNITTING MACHINES Sheet 4 of8 Filed Feb. 20, 1967 April 1, 1969 R. awn- 0130M E AL STRAIGHT'JBAR KNITTING MACHINES Sheet Filed Feb. 20, 1967 April 1, 1969 w o ET AL 3,435,637

STRAIGHT-BAR KNITTING MACHINES Filed Feb. 20, 1967 Sheet of s April 1, 1969 RF. WHOLTON ET AL 3,435,637

STRAIGHT-BAR KNITTING MACHINES Filed Feb. 20, 1967 Sheet 7 of a,

April 1, 1969 R. F. WHOLTON ETAL 3,435,637

STRAIGHT-BAR KNITTING MACHINES Filed Feb. 20, 1967 Sheet 8 018 United States Patent Office 3,435,637 Patented Apr. 1, 1969 3,435,637 STRAIGHT-BAR KNITTING MA'CHINES Reginald F. Wholton, Syston, and Clive Cartledge, Arnold,

England, assignors to Textile Machinery Developments Limited, Leicester, England, a British company Filed Feb. 20, 1967, Ser. No. 617,204 Int. Cl. D04b 11/14, 11/26 US. Cl. 66-88 20 Claims ABSTRACT OF THE DISCLOSURE A plain straight-bar knitting machine having a plurality of knitting sections and normally adapted to produce only non-rib fabric. Invention provides initially separate conversion units, applied one to each section to convert the machine into one capable of changing from rib to plain knitting. Each unit comprises a unitary sub-framework supported from a longitudinal member of the machine frame, and includes a bar of horizontal machine needles, a rib knock-over slide and means in the sub-framework operated and controlled from a main cam shaft of the machine for producing motions of the said bar and slide.

This invention relates to straight-bar knitting machines of the Cottons patent or similar type.

Such a machine is divided up into sections or heads each adapted to knit a garment blank, and basically includes, in combination, a sectional needle bar equipped with simultaneously operable vertical frame needles, thread carriers or guides-at least one to each section or headfor laying the thread and feeding them to the needles, sinkers for sinking and holding down the loops, means for closing the needle hooks at appropriate times and means for knocking over the old loops.

Usually, but not essentially the said frame needles are of the bearded type, in which instance the means for closing the needle hooks are in the form of beard pressers.

The invention may advantageously be applied to fullyfashioned straight-bar knitting machines which, as well known to those acquainted with the knitting machinery art, are equipped with fashioning mechanism including points the function of which is to take ofi, at intervals as required, certain of the selvedge loops and to replace them on needles either inwards or outwards according as to whether the knitted fabric is to be narrowed or widened.

In a straight-bar plain knitting machine for producing plain (non-rib) fabric, there is only a single line of frame needles, usually vertically disposed comprising all the needles set in the aligned sections of the needle bar.

But in a straight-bar rib machine capable of producing rib fabric there are two needle bars furnished with lines of needles for drawing loops in respectively opposite directions, viz. a line of frame needles and a line of socalled machine needles.

In particular, the invention is concerned with, and in the result aims to provide, a straight-bar knitting machine of a previously proposed form adapted to produce rib and plain (non-rib) fabric and to change at required times from rib to plain knitting, such a machine for this purpose having, in combination, vertical frame needles operable simultaneously in producing plain fabric, and rib to plain transfer mechanism comprising means for causing selected vertical needles not to knit for rib fabric, and, corresponding to these selected frame needles, an arrangement of horizontal machine needles operable, when rib fabric is to be knitted, to receive yarn and rib knit with the remaining vertical needles, and when plain fabric is to be knitted, to transfer (or have transferred) loops thereon to said selected vertical needles.

A straight-bar knitting machine of this previously proposed form thus, for instance, avoids the necessity for the production of, say, rib borders or welts on a separate rib machine and their transfer to a plain machine for plain (non-rib) fabric to be knitted onto them in continuation thereof.

The primary object of the present invention is to provide efficient and economical attachments of robust form which can be separately produced and sold for application to existing straight-bar basically plain knitting machines to convert the latter into machines of the aforementioned previously proposed form.

Nevertheless, it is also within the broad scope of the invention to similarly convert into a machine of the previously proposed form a conventional straight-bar rib machine, the conversion in this instance involving, inter alia, wholesale removal of both the bar of machine needles and the conventional means for operating the same and the replacement of these, at the various machine sections, by attachments separately produced in accordance with the present invention. As will be appreciated, however, the first phase of this particular conversion is so to modify such a rib machine by subtraction therefrom as to produce a basically plain straight-bar knitting machine of the type herein referred to suitable for having the present invention applied thereto.

According to this invention there are provided, in a basically plain straight-bar knitting machine of the type herein referred to normally adapted to produce only nonrib fabric, initially separate conversion units applied one to each section or head of this existing machine to convert the latter into a machine of the form adapted to produce rib and plain fabric and to change at required times from rib to plain knitting, each of said units comprising, in combination, (a) a unitary sub-framework which includes spaced side plates and is secured to and supported from an existing longitudinally extending member of the machine frame, (b) a movable bar of horizontal machine needles housed within the said sub-framework, (c) a rib knock-over (K.O.) slide in the sub-framework for both controlling rib fabric in relation to the vertical frame needles of the machine and the aforementioned horizontal machine needles and also assisting in knocking-over rib loops during transfer thereof to selected frame needles, and (d) means accommodated within the sub-framework and operated and controlled from a main cam shaft of the existing machine for producing the necessary motions of the bar of machine needles and the rib K.O. slide.

Associated with each conversion unit, and either forming a part thereof or being separate therefrom and adapted for attachment to the relevant section or head of the basically plain machine itself, are (e) means for preventing selected frame needles from knitting during the production on the machine of rib fabric but permitting such needles to receive loops when plain fabric in continuation of said rib fabric is to be knitted.

Although, generally speaking, the selected frame needles at each section or head will be the alternate ones of the line so that the straight-bar knitting machine to which the conversion units of this invention are applied will produce 1 x l rib fabric, there is no limitation in this respect since such selected needles may be so interspersed with Lin-selected frame needles that in collaboration with a complementary set out of machine needles, the head or section of the machine will be capable of producing a rib combination other than 1 x 1.

Where, as may be, the aforementioned means (d) in each sub-framework (a) comprises self-contained cam and lever systems for producing the necessary motions both of the machine needle bar and also of the rib knockover slide each initially separate conversion unit may conveniently include an auxiliary cam shaft assembly adapted to rotate at the same speed as the main cam shaft of the existing straight-bar knitting machine to which the separately produced conversion units of this invention are applied.

It is to be clearly understood, however, that instead of providing cam and lever systems operated by or from an auxiliary cam shaft, it is possible to incorporate in the sub-framework of each conversion unit electro-magnetic linear actuators or fluid-operated piston and cylinder devices or equivalent operated and controlled by or from a master cam, e.g. attached to the main cam shaft of the machine, and adapted to operate programmed switch means of any appropriate character.

As will be appreciated, the idea, in any event, is to provide what is virtually a kit of attachments by means of which an existing straight-bar knitting machine, more especially a plain machine originally equipped with vertical frame needles only, can with a minimum of labour and at relatively small cost be converted into a desirable straight-bar rib knitting machine of the particular previously proposed form herein defined, i.e. a machine having the facility to transfer from rib to plain and thus to knit, without interruption, plain fabric in continuation of rib fabric.

As to (e) above, such means may take any one of several forms a few of which will now be broadly described.

Thus, and especially where the vertical frame needles are of the spring beard type, the said means (e) may advantageously consist of a common bar furnished with a series of masking blades-one to each machine needle of the section or head concernedthese blades being adapted, whenever the said bar is operatively positioned manually or automatically, to mask the beards of the selected frame needles which are thereby prevented from knitting by virtue of the yarn fed to them being cast off during production of rib fabric.

A bar furnished with masking blades may, if desired, be spring-loaded by conveniently arranged springs of either the compression or extension type. Such a carrier bar, moreover, may advantageously be located above the frame needles and supported from the sinker head of the machine.

However, a masking blade bar, whether or not it is spring loaded and adjustable for stitch length, may alternatively be carried by the conventional catch bar of the machine used for pushing forward dividers for dividing loops in known manner.

Each conversion unit may also embody, or can be used in conjunction with, some means for either facilitating or actually effecting transfer of loops from the relevant bar of machine needles to the selected vertical frame needles-preparatory to knitting plain fabric in continuation of rib fabric.

In order that the invention may be more clearly understood and readily carried into practical effect, one constructional form of a conversion unit for the intended purpose, and a specific example of a masking blade bar attachment will now be described with reference to the accompanying purely schematic drawings, wherein,

FIGURE 1 is a vertical cross-sectional view through so much of what was originally a plain straight-bar knitting machine as is necessary to show the application thereto, at one section or head thereof, of a conversion unit for converting the said machine into a rib knitting machine of the form herein referred to,

FIGURE 2 is a front view of one such complete conversion unit,

FIGURE 3 is a plan view of the same, partly in section,

FIGURE 4 is a vertical cross-sectional view taken on the line IV-IV of FIGURE 3, showing more particularly the cam and lever systems for producing the required motions of the bar of machine needles,

FIGURE 5 is a further vertical cross-sectional view taken on the line VV of FIGURE 3 and illustrating the cam and lever system for producing the necessary movements of the rib K.O. slide,

FIGURE 6 is a detail vertical sectional view in part taken on the line VI-VI of FIGURE 4 depicting the carrier means for the bar of horizontal machine needles and the auxiliary cam shaft assembly of the conversion unit,

FIGURE 7 is an enlarged detail cross-sectional view taken on the line VII-VII of FIGURE 3,

FIGURE 8 is an enlarged detail front view, partly in section on the line VIII-VIII of FIGURE 3, showing one end of the masking blade bar provided at the illustrated section or head of the machine,

FIGURES 9 and 9A are broken plan views of alternative forms of the masking blade bar,

FIGURE 10 is a composite view showing a front view, a vertical sectional view and a cross-sectional view of the operative portion of an alternative form of masking blade,

FIGURE 11 is a diagram depicting means to facilitate manual transference of loops from relevant machine needles to selected vertical frame needles,

FIGURE 12 illustrates an alternative form of means to assist such manual transference of loops, and

FIGURE 13 is a plan view of a special form of rib K.O. slide incorporating loop-spreading devices designed for automatic transference of loops from relevant machine needles to selected vertical frame needles as aforesaid.

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

Referring to FIGURE 1, it will be seen that the existing horizontal template bar or rail of the main frame of the machine is indicated at 1. The reference numeral 2 indicates the main cam shaft of the machine. The vertical frame needles 3 at each section or head of the machine are mounted in a bar 4. The conventional sinkers are provided at 5, the jacks for the sinkers at 6 and 7 represents the usual slurcock mechanism for operating these jacks. 8 is the catch bar for operating the sinkers 5, which bar is operable, through the medium of mechanism 9 actuated by a cam 9 on the shaft 2. Merely for identification purpose, one of a plurality of thread carriers is shown at 10, this being operated by a thread carrier bar 11. A lever system 12, also operated from the main cam shaft 2, imparts the necessary movements to the bar 4 of vertical frame needles 3. The customary pressing motion of the frame needles 3 is effected by a cam-operated mechanism 13, whilst the cam-operated mechanism indicated at 14 is for the knocking-over bits 15.

The portion of the conventional basically plain straight-bar knitting machine illustrated in FIGURE 1 is further identified by a purely diagrammatic showing of the customary narrowing head 16, and at 17 as indicated the hand-wheel shaft of the machine.

In accordance with the present invention, an existing plain machine such as that just described in very broad terms with reference to FIGURE 1, has applied to each section or head thereof a conversion unit CU, these units serving to convert the machine into one of the form adapted to produce both rib and plain fabric and having the facility to change at required times from rib knitting to plain knitting in continuation of the rib knitting.

As shown more clearly in FIGURES 2, 3, 4, 5 and 6, each conversion unit CU (only one of which is shown) basically comprises a unitary sub-framework which includes, at each side thereof, suitably spaced inner and

outer side plates

18 and 19 respectively. For strengthening purposes, the peripheries of the

side plates

18 and 19 are respectively formed with opposing

inturned flanges

18a and 19a. The four side plates are rigidly secured together to provide a framework by means of longitudinally extending horizontal tie rods such as 20 some of which carry comparatively short distance pieces 21 to maintain separation of the two plates of each pair, and longer distance pieces 22 to determine the distance apart of the opposed side plates 18. Where, as indicated at 23 in FIGURES 2 and 3, a horizontal rod or shaft of the basically plain straight-bar knitting machine is required to extend freely through a conversion unit CU, the four side plates are, of course, formed at appropriate locations with holes to permit the said rod or shaft to pass through.

As will be seen most clearly in FIGURES 4 and 5 each of the side plates is provided with a thickened bearer part 24 which is machined with horizontal and

vertical faces

24a and 24b respectively adapted to rest upon the top and to bear against the back of the template bar or rail 1. To secure the framework of each conversion unit CU firmly in position upon the said template bar or rail 1 there is mounted to turn about the axes of a horizontal pivot pin 25 carried by and at the inner side of each outer side plate 19 a radially adjustable screwthreaded link 26 which at its inner end is articulated as at 27 (FIGURE 4) within a bifurcated portion 28a of a bearer element 28. Each such element is recessed at 28b for engagement with the lower front corner of the template bar or rail 1. Thus, by appropriate manipulation of nuts 29 engaged with the screwthreaded links 26, the bearer elements 28 can be forced upwardly against the underside and the front of the template bar or rail 1, thereby drawing the

side plates

18 and 19 forwardly and downwardly so that the machined faces 24a and 24b of their bearer parts 24 firmly engage the top and the back of the said bar or rail. Additionally, however, the sub-framework of the unit CU is supported lower down and at the front upon the hand-wheel shaft 17. To make such additional support possible, each of the four

side plates

18 and 19 has formed therein a vertical slot 30 open at its lower end to enable the plate, when being positioned, to be engaged over the shaft '17. Surrounding the upper closed end of each slot 30 is a part-circular pad 31 constituting a thickened part of the corresponding side plate. This part is drilled with a circular series of tapped holes 32 (see FIGURE 4) to permit of the attachment to the relevant side of the plate, by means of screws 33, of two

complementary halves

34 and 34 of a split bearing through which the tnunable hand-wheel shaft 17 extends.

Housed within the back part oft he sub-framework of each conversion unit CU, i.e. the part nearest to the knitting sections or heads of the converted plain machine, is a horizontal machine needle bar support bracket 35. Against the undersides of horizontal end portions 35a of this bracket are secured, by means of screws 36, fiat horizontal attachment lugs 37a extending laterally from opposite ends of the lower part 37 of a composite machine needle bar NB. The upper part 38 of this bar is most clearly seen in FIGURE 7. The upper face of the lower part of the .bar NB is tricked to receive the horizontal machine needles 39, the tails of the stems of these needles being accommodated in vertical holes 40. The lower and

upper parts

37 and 38 are clamped together, by means of screws 41, with a piece 42 of leather or the like interposed between them. The upright back portion 35b of the needle bar support bracket 35 is attached, by means of screws 43, to a straight carrier bar 44 of flat cross-section the opposite ends of which extend freely through openings 45 cut in the inner side plates as depicted most clearly in FIGURE 3.

In the upper part of the space S between each pair of

side plates

18, 19 is a bracket 46 which is of rightangular form as viewed in plan (see the right-hand side of FIGURE 3). These two brackets 46, one left-hand and the other right-hand, in turn serve to support the carrier bar 44 and hence the entire machine needle bar assembly. Thus, as will be seen in FIGURE 3, the end portions 44a of the carrier bar 44 are drilled to receive screws 47 by means of which the said bar is attached to the inturned or laterally extending portions 46a of the support brackets 46. The outer face of the forwardly extending limb 46b of each such bracket 46 has thereon two spaced

lugs

48 and 48 which are drilled with axially aligned holes and slidably engaged with a slideway 49 of rod form. Each round-section rod 49 constituting such a slideway is secured at its ends within drilled lugs 50 and 51 formed on the top edge of a lever 52 which is bossed at 53 and arranged to turn about a horizontal pivot 54 fixed in position between the relevant pair of inner and

outer side plates

18 and 19. Hence, there are two of the levers 52one left-hand and the other right-handat respectively opposite ends of the machine needle bar assembly. These two levers 52 are connected by an eccentrically mounted rod 55 which is held in any position to which it may be turned (for an adjustment purpose hereinafter to be explained) by means of screws 56 passed inwardly through the said levers into tapped holes formed eccentrically in the ends of the rod 55 as illustrated in FIG-

URES

3 and 6.

The left-hand and right-hand support brackets 46 are rigidly connected together by a cross rod 57 (see FIG- URES 3 and 4). On the opposite end portions of this cross rod 57 extending between the respective pairs of inner and

outer side plates

18, 19 are pivotally mounted forwardly extending horizontal needle bar actuating links 58. The outer end of each link 58, near to the front of the conversion unit CU, is screw-threaded at 58a to receive nuts 59 for facilitating adjustment of a bifurcated coupling component 60 mounted on the said link. Each bifurcated component 60 constitutes the means whereby the corresponding needle bar actuating link 58 is coupled to the upper, suitably bossed end of an upwardly directed limb 61a of a two-armed cam lever 61 which is accommodated between the relevant pair of inner and outer side plates and is centrally bossed at 61b to take a bearing on a horizontal fulcrum rod 62 extending right across the unit. The two cam levers 61 are respectively left-hand and right-hand, their upwardly directed limbs 61a being connected, for the sake of rigidity, by a rod 63 which extends through elongated openings 64 formed in the inner side plates 18 (FIGURE 4). The lower, bossed ends of the downwardly directed limbs 610 of the two cam levers 61 are similarly connected by a cross-rod 65 which, like the rod 63, extends through elongated openings 65 formed in the lower portions of the two inner side plates 18. The rod 65, however, also serves to carry a cam follower roll 66 arranged to engage, at appropriate times, the appropriately contoured edge of a rib cam 67 mounted on an auxiliary cam shaft 68 the details of which will be hereinafter described. The cam 67 effects and controls the horizontal to and fro movements of the machine needles 39. The horizontal movements of the machine needle bar assembly are also subject to the restraining influence of tension springs TS one of each of which is anchored to a pin P upstanding from a collar on the cross rod 57, adjacent to the inner side of the relevant support bracket 46, whilst the other end is anchored to a pin P extending inwardly from the corresponding outer side plate 19 all as shown in FIGURES 3 and 4.

The beards 39a of these machine needles are arranged to be pressed at the required times during rib knitting by contact thereof with presser faces 69 and 70 (FIGURE 7) presented below the sinker head SH of the machine. In accordance with conventional practice, the said machine needles require to be moved up and down heightwise for beard pressing. These up and down movements are achieved by the action on the underside of the eccentrically mounted rod 55 of left-hand and right-hand relatively wide levers 71 of a flat cross-section accommodated between the pairs of inner and outer side plates. The rear end of each flat lever 71 is bossed at 71a on its underside to take a bearing on a fulcrum pin or rod 72. The top surface 71b of the rear portion of each such flat lever, which surface engages the underside of the eccentrically mounted rod 55, has an accurately ground finish. The leading, i.e., front, end of each lever 71 is forked at 71c and suitably slotted for coupling to the upper end of a vertical pin 73. Each of these pins 73, one at each side of the conversion unit, is arranged to slide up and down freely through

hushed bearings

74 and 75 carried by a bracket 76 attached to the relevant inner side plate 18, as depicted in FIGURES 4 and 6. The lower ends of the two vertical pins 73 are rigidly secured to and connected by a common bracket structure 77 which is, of course, bodily movable up and down under the guidance of the pins 73. As seen more clearly in FIGURE 6, the underside of the lower part 77a of the bracket structure 77 is forked at 77b and fitted with an axle pin 78 designed to carry a cam follower roll 79 arranged to engage, at appropriate times, the appropriately contoured edge of a rotary cam 80 mounted upon the auxiliary cam shaft 68. The cam 80 effects and controls the vertical pressing movements of the horizontal machine needles 39. The aforesaid lower part 77a of the vertically slidable bracket structure 77 has set in the centre thereof a vertical screwthreaded pin 81 which extends up through a hole formed centrally in the upper bar 770 of the said structure and has nuts 82 applied thereto as shown in FIGURES 2, and 6. To steady the upper bar 77c in relation to the lower part 77a, the latter is also provided, at respectively opposite sides of the central screwthreaded pin 81, two plain vertical guide pins 83. Thus, by suitable manipulation of the two nuts 82, the upper bar 770 can be initially raised or lowered in relation to the lower part 77a to achieve a final adjustment determining the amount of press on the beards 39a of the horizontal machine needles 39.

A preliminary adjustment to determine the required amount of vertical (press) movement of the needle bar NB can be effected by slackening the nuts 56, suitably turning the eccentric rod 55 and re-tightening the said nuts. Such an adjustment slightly varies the leverage, i.e., the distances between the fulcra of the levers 71 and the lines of contact between these levers and the eccentric rod 55.

From the foregoing description it will accordingly be appreciated, in summary, that the conjoint horizontal and vertical movements of the machine needles 39 set in the needle bar NB are imparted and controlled by the two earns 67 and 80 rotating together with the auxiliary cam shaft 68. Specifically, the horizontal to and fro movements of the needle bar NB, respectively against and under the influence of the two tension springs TS, are effected and controlled by the rib cam 67 through the medium of the two two-armed cam levers 61, the cam follower roll 65, the actuator links 58 and the two needle bar support brackets 46 which are slidable back and forth along the slideway rods 49. On the other hand, the vertical up and down movements of the machine needles, for the pressing of the beards 39a, are effected and controlled by the cam 80, through the medium of the vertically slidable bracket structure 77, the vertical pins 73 and the two flat levers 71 which act on the underside of the eccentrically mounted rod 55.

An initial adjustment to determine the amount of the horizontal displacement of the machine needles 39 can be effected by appropriate manipulation of the nuts 59 on the screwthreaded ends 58a of the needle :bar actuating links 58.

The rib K.O. slide necessarily provided for operation in conjunction with the machine needles 39 is indicated by the numeral 84. As will 'be seen in FIGURES 1 and 5 this slide 84, which is tricked, is carried by bossed brackets 85 which are arranged to turn radially about pivots 86 carried by the lower ends of two arms 87 respectively disposed on the outer sides of the two outer side plates 19. The arms 87 depend from fixed pivots, like that shown at 88 in FIGURE 3, combined with spacer elements interposed between the pairs of inner and

outer side plates

18 and 19. The K.O. slide pivot brackets are controlled by tension springs 88 arranged, as shown, to bias the slide upwardly into yieldable engagement with the backs or undersides of the horizontal machine needles 39. In actuating the rib K.O. slide 84 for the usual purpose, the depending arms 87 are swung to and fro about the pivots 88 by means of a rotary cam 89 on the auxiliary cam shaft 68, through the medium of connections now to be described. These connections include an arm 90 which is fitted with a cam follower roll 91 arranged to be engageable with the contoured edge of the cam 89. The arm 90 is rigidly secured to and extends downwardly from a cross shaft 92 which extends through and is turnable within bearings formed in the inner and

outer side plates

18 and 19--or in the two outer plates 19 only. In either event, the opposite end portions of the turn able cross shaft 92 project right through, and to the outer sides of the side plates 19, each of such projecting portions having pinned thereto an upwardly and rearwardly extending lever 93. The two levers 93 are thus disposed at the outer sides of, and closely adjacent to, the outer side plates 19 as clearly illustrated in FIGURE 2. The upper ends of the said levers 93 are connected to the depending arms 87 by means of straight links 94 (see FIG- URES l, 5 and 7). Shoulder bolts are provided at 95 to connect the opposite ends of the links 94 respectively with the arms 87 and the levers 93. In this regard, each of the arms 87 and each of the levers 93 is formed with a straight series of communicating holes 96 to permit of appropriate adjustments of the links 94 to vary the amount of knock-over. Thus, the shoulder bolts are appropriately moved upwardly or downwardly along the arms 87 and the levers 93 to secure fine adjustments.

As shown in FIGURE 6, the three

cams

67, 80' and 89 are accommodated in annular recesses formed in

rings

97, 98 and 99 respectively which rings are mounted upon a reel or sleeve 100 and clamped up together thereon by means of a nut 10*1 applied to a screwthreaded end of the said reel. The latter is longitudinally grooved at 100a to receive a key spline 102 set in the auxiliary cam shaft 68. This enables the reel 100 to be shifted axially from the right-hand position shown in FIGURES 2 and 6 to a left-hand position (not shown). When the reel is in its right-hand position the three cam follower rolls 66, 79 and 91 are respectively engaged with the rib cam 67, the pressing cam 80 and the rib knock-over cam 89 for rib knitting. But when this reel is shifted into its left-hand position, for plain knitting,

blufiing cams

103, 104 and 105 also mounted on the said reel in alternating relation with the

cams

67, 80 and 89, are presented to the cam follower rolls 66, 79 and 91 respectively. The three bluffing cams are so peripherally contoured as to impart no movements, or at least no operative movements to machine needle bar NB and the rib K.O. slide 84. That is to say, by virtue of shifting the reel 100 from right to left the rib knitting attachments, previously operative, are rendered inoperative to enable the machine to continue knitting plain only. To enable the reel 100 to be so shifted, the end thereof remote from the nut 10 1 is formed integrally with an enlarged circumferentially grooved portion 10% designed to be engaged by a forked shift lever 106 (see FIGURES 2 and 6).

The auxiliary cam shaft 68 is mounted for rotation in bearings such as 107 and 108' (FIGURE 6) secured in the inner and

outer side plates

18 and 19, and this shaft has rigidly secured thereon a chain sprocket 109 around which and another chain sprocket 110 mounted on a drive shaft 111 is passed an endless chain 112. The

sprockets

109 and 110 are of the same size, i.e. each have the same number of teeth, whilst the drive shaft 111 is additional to the normal drive means of the machine. Also mounted on the shaft 111 and rotatable together with the chain sprocket 110 is a somewhat larger chain sprocket 113 around which and a further chain sprocket 114 on the main cam shaft 2 of the machine is passed another endless chain 115'. The

sprockets

113 and 114 are of the same size as one another, the arrangement accordingly being such that the auxiliary cam shaft 68, individual to each conversion unit CU, rotates at the same speed as the main cam shaft 2.

The roller indicated at 116 is a fabric support roller.

As previously mentioned, there is provided at each section of head of the machine, in association with the conversion unit CU thereat, any suitable means for preventing selected vertical frame needles 3 from knitting during the production on the machine of rib fabric but permitting such needles to receive loops when plain fabric in continuation of said rib fabric is to be knitted. Thus, in the specific conversion illustrated in FIGURES l-8, applied to a plain straight-bar knitting machine wherein, as shown, the frame needles 3 are of the spring beard type, the said means is in the form of the masking blade assembly indicated generally at 117 in each of FIGURES l, 3, 5, 7 and 8. As will be seen, this assembly comprises a common bar 118 from the underside of which depend a series of masking blades 119' of flat form arranged to be positioned laterally alongside the beards 3a of the selected frame needles as illustrated in FIGURE 7. Where, as in the present case, the conversion is adapted to produce 1 x 1 rib knitting, the number of masking blades 119 equals half the number of frame needles 3 and the full number of machine needles 39. The bar 118 is mounted on the flat top of a carrier 120 of angle section and is secured thereto by means of screws 121 which may, as shown, extend down through elongated holes 118a formed in the bar to permit of adjustments of the latter back and forth within limits to vary the quality, i.e. stitch length, of the rib knitting. Such adjustments may be made in any other suitable manner. The opposite ends of the bar carrier 120 have attached thereto brackets 122 the outer ends of which are provided with laterally extending housings 123 for manually operable spring plungers 124. The inner ends of these housings are drilled vertically and the brackets 122 are similarly drilled and counterbored at 122a in such a way as to enable the whole masking blade assembly 117 to be slida-bly engaged with vertical pins 125 set in the existing sinker head SH of the machine. As shown in FIGURE 8, the lower ends of each vertical pin 125 is screwthreaded for screwing into a tapped hole formed in the sinker head SH, whilst an intermediate portion 125m of the pin is screwthreaded to receive an adjustable nut 126. The nuts 126 constitute heightwise adjustable abutments for supporting the brackets 122. The upper plain portions of the vertical pins 125 are grooved at 1251) for engagement by the inner ends of the spring plungers 124. The arrangement is simply this: that to render the masking blade assembly 117 inoperative, the knobs 124a of the plungers 124 are pulled out and the assembly is lifted up along the pins 125 by which it is guided, the plungers thereupon being released to retain the assembly in its raised position. Conversely, the knobs are pulled out to release the assembly and enable it to fall into its operative position determined by contact of the undersides of the brackets 122 with the tops of the adjustable nuts 126. The bar carrier 120 is attached to the undersides of the brackets 122 by means of screws 127 which extend through elongated holes 1202: formed in the said carrier to enable the masking blade bar 118 to be longitudinally adjusted. It is to be understood that in FIGURES 5 and 7 the needle 3 is shown in a starting position and, to enable its heard to be masked by the lower narrowed portion of the blade 119, the needle must first be moved down and away from the presser face.

The masking blade bar may alternatively be adjusted upon the carrier 120 in the manner depicted in FIGURE 9. Or, as shown in FIGURE 9A, the bar 118 may be spring-loaded by conveniently arranged springs of either the compression or extension type.

In an alternative form of the masking blade assembly, instead of blades of fiat form being employed, the operative portions of the blades, indicated at 128 in FIGURE 10 are of U-shape in cross-section suchwise as to provide in front of each selected vertical frame needle 3 a spoonlike formation 128a channelled or grooved to temporarily receive and shroud the needle beard 3a. Masking blades of this alternative form may be arranged for either pivoting or sliding to facilitate movement thereof into and out of their operative positions.

Also as previously mentioned herein, each conversion unit CU may also embody, or can be used in conjunction with, means for facilitating or actually effecting transfer of loops from the machine needles 39 set in the needle bar NB to the selected vertical frame needles 3.

Such a transfer of rib loops may be executed either manually or automatically. To facilitate manual transfer, there may be provided for use in conjunction with each machine needle bar NB a bar (not shown) carrying grooved transfer points such as those indicated at 129 in FIGURE 11 operable to pick-up rib loops on the machine needles 39 and transfer them on to the selected frame needles 3. Alternatively, and especially in a case where, as shown, the horizontal machine needles 39 are of the bearded type, these needles, set in a bar which is readily attachable to and detachable from the conversion unit, may themselves have rib loop-spreading shanks 39b the undersides of which are longitudinally grooved at 390 to receive the heads of the selected vertical frame needles.

In one example of the invention, embodying an automatic rib loop transfer system but applicable only to a coarse gauge machine, the machine needle shanks may have upturned rear ends of channelled or grooved form, so that, in a rib to plain transfer, loops on these ends are received by selected vertical frame needles moving upwards in the channels or grooves.

The K.O. slide 84 may, if desired, and as shown in FIGURE 13, incorporate loop-spreading devices 130, one to each horizontal machine needle 39 in the needle bar NB, these devices being arranged in grooves 131 in the slide and the latter being appropriately operable either from above or from below the said horizontal machine needles. Such a K.O. slide may be longitudinally split, and is for automatic rib loop transference.

To enable the invention to be applied to certain forms of existing straight-bar knitting machines, greater clearance than usual must be provided between the customary knock-over bits 15 and the horizontal needles 39 when rib knitting. To achieve such a clearance, the existing knock-over cam may be suitably modified or any other expedient which suggests itself to a person skilled in the art may be adopted. Moreover, an additional needle bar cam and follower on the main machine shaft is required to provide a different knock-over position for the relevant vertical frame needles during rib knitting.

When the herein described attachments of this invention are applied to a straight-bar knitting machine, one convenient method of turning a Welt and starting-up is as follows:

First, preliminary courses of plain fabric are knitted of a yarn fed in by one auxiliary carrier, whereupon the fabric is hooked-up with the existing take-up mechanism. Then, a draw-thread supplied by a second carrier is knitted into the plain fabric. A main carrier is next introduced for the first course in a 1 x l rib but before rib knitting commences, the horizontal machine needles may be caused to idle for three or four courses to produce a roll welt. An alternative procedure may comprise the steps of introducing a set-up wire after one course of 1 x l rib has been knitted of yarn supplied by the main carrier, hooking-up, then knitting a single or two course draw-thread followed by a roll-welt and 1 x l rib. When using grooved horizontal needles in a detachable needle bar for the manual transfer of rib loops to selected vertical frame needles, a set-up comb similar in design to that used on a flat knitting machine may be employed.

We claim:

1. A straight-bar knitting machine of the type which is divided up into sections each adapted to knit a separate fabric and which comprises a frame including longitudinally extending member, a sectional needle bar mounted in said frame and equipped with simultaneously operable vertical frame needles having hooks, at least one thread carrier to each section for laying threads and feeding said threads to the said needles, sinkers for sinking thread about said needles and for holding down loops formed by the said needles, means for closing the needle hooks, means for knocking over old loops, and a main earn shaft for operating and controlling said frame needles, said sinkers, said closing means and said knocking over means, wherein the improvement comprises the addition of initially separate conversion units to each section of the machine for converting the machine from a basically plain machine into a machine adapted to produce rib and plain fabric and to change at required times from rib to plain knitting, each of said units comprising in combination, a unitary sub-framework including side plates, said framework being secured to and supported from an existing one of said longitudinally extending members; a movable bar of horizontal machine needles housed with the said subframework; a rib knock-over slide in the sub-framework for controlling rib fabric in relationship to the said vertical frame needles and the said horizontal machine needles and for assisting in knocking-over rib loops during trans fer thereof to selected frame needles; and means accommodated within the said sub-framework and operated and controlled from the said main cam shaft for producing movement of the said bar of machine needles and of the said rib knock-over slide.

2. A straight-bar knitting machine according to claim 1, 'which includes, in association with each conversion unit, an attachment equipped with means for preventing selected frame needles at the relevant section of the machine from knitting during the production of rib fabric but permitting such needles to receive loops from the machine needles in the unit when plain fabric in continuation of said rib fabric is to be knitted.

3. A straight-bar knitting machine according to claim 2 and having vertical frame needles of the spring beard type, wherein each of said attachments consists of a movable carrier bar furnished with a series of masking blades, one to each section of the machine, said blades being adapted, whenever the said bar is moved into an operative position at the section, to mask the beards of the selected frame needles which are thereby prevented from knitting by virtue of the yarn fed to them being cast off during the production of rib fabric.

4. A straight-bar knitting machine according to claim 3, wherein the masking blades of each attachment are of flat form arranged to be positioned laterally alongside the beards of the selected frame needles.

5. A straight-bar knitting machine according to claim 3, wherein the masking blades of each attachment are of U-shape in cross-section suchwise as to provide in front of each selected vertical frame needle a spoon-like formation channelled to temporarily receive and shroud the needle beard.

6. A straight-bar knitting machine according to claim 3, wherein the masking blade carrier bar of each attachment is in turn carried by brackets which are drilled for engagement with vertical guide pins on a sinker head of the machine and are provided with retaining means cooperable with said pins, the said carrier bar being adapted to be raised up manually along the pins and held by the retaining means in an inoperative position, and released by manipulation of said retaining means to enable it to drop down the pins into an operative position.

7. A straight-bar knitting machine according to claim 1, 'wherein the spaced side plates of each conversion unit have parts presenting faces which are engaged respectively with the top and the back of the template bar of the machine, appropriate ones of said side plates having articulated thereto adjustable bearer elements formed for engagement with the lower front corner of said template bar so that by adjustment of the said bearer elements the latter can be forced upwardly against the underside and the front of the said bar, thereby drawing the side plates forwardly and downwardly.

8. A straight-bar knitting machine according to claim 1, wherein each of the side plates has formed therein a vertical slot open at its lower end to enable the plate, when being positioned, to be engaged over a hand-wheel shaft for turning the machine by hand, two complementary halves of a split bearing through which said shaft extends being attached to each side late in the region of the upper closed end of the vertical slot therein.

9. A straight-bar knitting machine according to claim 1, wherein each conversion unit includes an auxiliary cam shaft assembly, means whereby said auxiliary cam shaft is driven at the same speed as the main cam shaft of the machine, cams on the auxiliary cam shaft, and levers and linkages which are operable and controllable by said cams and are connected with the machine needle bar and the rib knock over slide for producing the required motions thereof.

10. A straight-bar knitting machine according to claim 9, wherein each conversion unit includes support means for the machine needle bar; guides along which said support means are movable to and fro, horizontally disposed pivoted levers on which said guides are provided; two cam levers which are fulcrummed in the unit; means laterally connecting said cam levers; links extending between said cam levers and said machine needle bar support means; a first cam on the auxiliary cam shaft from which the laterally connected cam levers are operated; means for action upon the undersides of the horizontally disposed levers to swing the latter up and down and so impart vertical movements to the machine needle bar; and a second cam on the auxiliary cam shaft from which the last mentioned means are actuated.

11. A straight-bar knitting machine according to claim 10, wherein the two horizontally disposed levers are laterally connected by means of an adjustable eccentrically mounted rod the underside of which rests upon upper surfaces of further fulcrummed levers which are connected with guided members movable up and down by means of a common bracket structure operated from the second cam on the auxiliary cam shaft assembly.

12. A straight-bar knitting machine according to claim 10, wherein the links extending between the cam levers and the machine needle bar support means have associated therewith screw adjustment means whereby adjustments to determine the amount of the horizontal displacements of the machine needles can be effected.

13. A straight-bar knitting machine according to claim 11, wherein the said common bracket structure comprises upper and lower horizontal parts which are relatively adjusta'ble 'vertically suchwise as to effect a final adjustment determining the amount of press on beards of the horizontal machine needles.

14. A straight-bar knitting machine according to claim 11, wherein the eccentrically mounted rod is adjustable by turning to effect a preliminary adjustment for determining the required amount of vertical (press) movement to be imparted to the machine needle bar, such an adjustment slightly varying the distances between the fulcra of the further fulcrummed levers and lines of contact between these levers and the eccentric rod.

15. A straight-bar knitting machine according to claim 10, wherein the rib knock-over slide in each conversion unit is carried by brackets arranged to pivot at the lower ends of depending arms in turn pivoted upon side plates of the unit, these arms being linked with connected levers arranged to be operated from a third cam on the auxiliary cam shaft assembly.

16. A straight-bar knitting machine according to claim 15, wherein the first, the second and the third cams are all mounted on a sleeve arranged for axial sliding movement along the auxiliary cam shaft, cam follower rolls for contact with the peripheries of these cams being included in the means through the medium of which the machine needle bar assembly and the rib knock-over slide are operated and controlled and the aforesaid sleeve being shiftable from one position in which the cam follower rolls are respectively engaged with the three cams during rib knitting to another position in which the rolls are disengaged from the cams during plain knitting.

17. A straight-bar knitting machine according to claim 16, wherein bluffing cams, also mounted on the sleeve in alternating relation with the aforementioned first, second and third cams, are provided for presentation to the cam follower rolls whenever the sleeve is shifted into its position for plain knitting, the aforesaid blufiing cams being 15 so peripherally contoured as to impart no operative movements to the machine needle bar and the rib knockover slide.

18. A straight-bar knitting machine according to claim 1, wherein each conversion unit is adapted to be used in conjunction with means facilitating transfer of loops from the relevant bar of needles to selected frame needles at the section preparatory to knitting plain fabric in continuation of rib fabric.

19. A straight-bar knitting machine according to claim 18, wherein horizontal needles of the bearded type set 14 in a bar attachable to and detachable from the conversion unit have rib loop-spreading shanks the undersides of which are longitudinally igrooved to receive the heads of selected frame needles.

20. A straight-bar knitting machine according to claim 18, wherein the rib knock-over slide incorporates loopspreading devices, one to each machine needle in the unit, these devices being arranged in grooves in the slide.

References Cited UNITED STATES PATENTS 621,723 3/ 1 899 Lowe 66'88 2,132,135 10/1938 Taylor -668 8 2,957,324 10/1960 Willner -6688- XR 2,984,092 5/1961 Start 66'88 3,050,967 8/1962 Taylor 668 8 3,111,828 11/1963 Brooke 668 3,376,717 4/1968 Scheller et a1. 66-88 XR RONALD FELDBAUM, Primary Examiner.