US3517529A - Knitting machine - Google Patents

Description

June 30, 1970 J. A. CURRIER KNITTING MACHINE 6 Sheets-Sheet 1 Filed Nov. 2, 196'? I INVENTOR JOHN A. CURRIER ON mm on on ATTORNEYS June 30, 1970 J. A. CURRIER 3,517,529

KNITTING MACHINE Filed Nov. 2 1967 6 Sheets-Sheet 2 INVENTOR JOHN A. CURRIER ATTORNEYS June 30, 1970 .3. A. cuRmER 3,517,529

KNITTING MACHINE Filed Nov. 2, 196'. 6 Sheets-Sheet 5 INVENTOR JOHN A. CURRIER ATTORNEYS June 30, 1970 J. A. CURRIER KNITTING MACHINE 6 Sheets-Sheet 4 Filed. Nov. 2, 196'.

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INVENTOR JOHN A. CURRIER ATTORNEYS June 30, 1970 J. A. CUlRRlER 3,517,529

KNITTING MACHINE Filed Nov. 2, 1967 6 Sheets-Sheet 5 F I G. 4.

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INVENTOR JOHN A. CURRIER ATTO RNEYS 6 Sheets-Sheet 6 Filed Nov. 2, 1967 mm mm INVENTOR JOHN A. CURRIER ATTORNEYS United States Patent 0 3,517,529 KNITTING MACHINE John A. Currier, Canterbury, N.H., assignor to Scott & Williams, Inc., Laconia, N.H., a corporation of Delaware Filed Nov. 2, 1967, Ser. No. 680,224 Int. Cl. D04b 9/54 US. Cl. 66-41 4 Claims ABSTRACT OF THE DISCLOSURE A knitting machine for the knitting of stockings beginning with the toe and terminating with a turned welt is provided with fabric tensioning means for control of welt fabric during welt knitting. Tubes provide a central passage for reception of the leg and preceding portions of a stocking, and an annular passage for reception of the welt fabric. Suction is controlled in both passages to secure tensioning conditions desired at different portions of the knitting operation.

BACK-GROUND OF THE INVENTION The present invention is particularly directed to an improvement in the machine and method for stocking production described in Currier Pat. 3,340,706 dated Sept. 12, 1967.

In accordance with this patent stockings are knit hav' ing the particular characteristic that toe pockets are produced by twisting fabric to effect closure without recourse to the usual looping procedure. For achievement of this type of toe pocket the stocking must be knit beginning at the toe, the knitting then proceeding through the foot, heel and leg portions, followed by the formation of a turned welt. The turned Welt comprises a pair of plies with the last knitted having its final course transferred to the needles to close the welt. The operation cannot be terminated by this transfer, but knitting must be continued to form a short tab since otherwise the transferred stitches would immediately open up. In accordance with the patent the tab is provided with run resisting structure and curls in such fashion that there is substantial resistance to raveling.

SUMMARY OF THE INVENTION The present invention relates particularly to the control of tensioning of fabric during and associated with the formation of the welt and tab. In particular, the invention is concerned with rectifying problems which have arisen in the knitting of long turned welts. A fabricreceiving tube provides inner and annular regions, and at the beginning of knitting of welt fabric the leg and preceding portions of a stocking are located inside this tube. As the knitting of the welt proceeds, fabric is received in the annular space outside the tube. In accordance with the invention suction is controlled by valves operated by the usual main pattern control of the machine to effect suction independently in both the regions inside and outside the aforementioned tube. Further controls remove the suction and the consequent tension of the fabric. Bunching of the welt fabric is prevented. During tab knitting all of the tension is removed. Thereafter press-off occurs and suction removes the completed stocking.

The objects of the invention relate to the satisfactory achievement of what has been outlined, and various detailed objects will become more apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A, 1B and 1C are successive portions, in sequence from top to bottom, of a vertical section taken through the knitting machine provided in accordance with the present invention;

FIG. 2 is a fragmentary section taken on a plane indicated at 22 in FIG. 1A;

FIG. 3 is a schematic diagram of the electrical connection leading to the heating element;

FIG. 4 is a fragmentary plan view illustrating the arrangement of the fabric as formation of the selvedge takes place;

FIG. 5 is a development of the cams operating on the needles and jacks, showing other associated elements; and

FIG. 6 is an elevation, partly in section, showing particularly certain pneumatic elements of the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT Only so much of the knitting machine is shown as is involved in the matters pertinent to the present invention, and references may be made to the foregoing Currier patent for other aspects of the machine and operation. This patent goes into detail concerning the matters of formation of the twisted toe and the other portions of the stocking, including the formation of the turned welt, preceding the tab formation, which is the matter of concern herein. Reference will be made first to aspects of construction which are essentially illustrated in said Currier patent.

The needle cylinder 2, driven for rotation and reciprocation, is provided with slots slidably mounting the latch needles 4 provided with the usual butts 5, the arrangement of which in the needle circle is as described in the Currier patent. Individually located below the needles in the same slots are the intermediate jacks 6 provided with butts 7, and beneath these are the usual pattern jacks 8 provided with the selectively removable butts l0 and with upper butts 12 and lower butts 14, these jacks being of the tiltable type provided with fulcra at 16 above which they are provided with ends 18 engageable by cams which tilt the lower ends outwardly for selection. These jacks are selected not only for conventional patterning operations but also to provide needle selection for various special operations in makeup and the like. The actuating cams for the selected butts It will be hereafter mentioned, without detailed discussion, however, of the conventional cam controlling means.

A sinker dial 2t and a sinker ring 22, both mounted to rotate and reciprocate with the needle cylinder, mount the sinkers 24 which are provided with the usual butts 26 acted upon by conventional cams mounted in the sinker cap 28. These sinkers provided with nebs and ledges are operated in the usual fashions at the two feeds.

The latch ring of the machine is indicated at 36', and mounts the bracket arrangement which serves for the mounting of various parts as shown in said Currier patent. The latch ring, as usual, is pivotally mounted so that it can be raised, carrying with it the bracket and the parts mounted thereby.

A transfer dial 34 is slotted to mount the transfer elements 40. These elements 40 are formed of two members associated side by side. These elements are provided with butts, those associated with the longer butt needles being high as indicated at 42 while those associated with shorter rbutt needles are low as indicated at 44. The differentiation of butts is merely to provide for the possibility of proper insertion and removal of operating cams.

3 The dial cap 36 mounts certain cams and also the outer cam ring 38.

Continuing the description of the basically conventional elements of the machine, reference may now be made to FIG. 5 showing in development various cams and other elements.

The latch ring 30 is provided at the main feed with a throat plate 46 from which yarns are fed from the usual feeding fingers of which only one is indicated at 48 in active position. Conventional yarn changing controls are used as will be readily understood to substitute different weights or types of yarn as desired. At the auxiliary feed a similar throat plate 50 is provided, and here also there are located the substitutable yarn feeding fingers of which only one is indicated at 52. Located at these feed positions are nozzles 54 and 56, to direct blasts of air inwardly against the fabric which is produced, thereby controlling its position and providing desired tension.

Cams and other elements operating on needle butts are generally conventional. A fixed cam 58 is arranged to raise needles to tuck height, and this is followed by radially movable ca ms 60 and 62, respectively adapted to raise needles to cleared height and to lower them to welt level. A fixed cam 64 raises needles to tuck level. The main feed center cam 66 is flanked by the forward and reverse switch cams 68 and 70 and their respective landing cams 72 and 74. A cam 76 following stitch cam 68 is arranged to raise needles to tuck level. Another cam above this indicated at 78 may raise needles to a low cleared level and this is followed by a cam 80 which may lower needles to tuck level. Following this is a further cam 82 arranged to raise needles to cleared level. All of these earns 76, 78, 80 and 82 are radially movable.

A pair of separate cams 84 and 86 constitute jointly the stitch cam arrangement at the auxiliary feed. Associated with the cam 86 is the landing cam 88, which is followed by the cam 58 already mentioned.

A radially movable cam 90 is located beyond cam 64 to lower needles. The usual switch cams 92 and 94, both radially movable, are provided. The lowering picker is indicated at 96, while the raising pickers 98 and 100 are indicated in inactive positions. It may be remarked that heel formation in accordance with the present invention is essentially conventional, though the sequence of heel formation is reverse, the lower or forward portion of the heel being first formed followed by the upper or rear portion. As specifically described in said Currier patent, the heel is formed single feed. It will be understood, however, that conventional arrangements for twofeed knitting of the heel may be provided.

The usual cams are provided at 102 and 104 for lowering the intermediate jacks 6 by action on their butts 7.

Conventional cam levers 106 are provided preceding the main feed for the selection of pattern jacks by action on butts thereof. The cam levers 106 rock the lower ends of the pattern jacks inwardly, and those which are so rocked miss the jackraising the cam 108 which acts on the butts 14 of those pattern jacks which are not rocked inwardly. In similar fashion pattern selection levers 110 are provided between the main and auxiliary feeds and are associated with a jack raising cam 112. Jack guard cams 114 and 116 are provided as usual. Cams 118 and 120 preceding the respective selecting cam levers 106 and 110 are arranged to engage the upper ends 18 of the pattern jacks to rock their lower ends outwardly for selection.

Referring to FIGS. 1A and 2, the heating assembly comprises the stationary bracket 122 fastened to the latch ring. An H-shaped block 124 carries the remainder of the assembly and is mounted in position by pivot pin 126 held in position by screw 128. By this arrangement the assembly may be adjusted and set to locate the heating element 134. A slot is milled in the latch ring to provide space for the unit. Slide 130 is movable in recessed parallel slots 132 in the block 124. The heating element 134 is for-med as a U-shaped loop swedged into two larger diameter parallel electrodes 136 that are inserted in brass terminal blocks 138 and clamped by screws 140. Conductor wire terminals 142 are fastened to the terminal block 138 by screws 144. A fibre T-shaped member 145 provides an insulator between the terminal blocks 138 and slide 130. Screws fasten the terminal blocks 138 and slide to the insulator in a fashion to maintain the required insulation of the conductive metal components.

The operative position of the heating element 134, as shown in FIG. 1A, is adjustable in its position by stop screws 148 bearing against block 124. Set screw 150 holds the stop screw 148 in position.

A conventional Bowden cable 152, having a sheath secured to the stationary bracket 122, is tensioned by the usual connections operated by cams on the main pattern drum to compress the spring 154 to move the slide assembly to operative position. The heating element 134 is moved radially outwardly beyond the needle circle to its inactive position upon movements of the main pattern drum as will be evident hereafter, whereupon Bowden permits the main cable to slacken and compressor 154 contracts the slide assembly.

The electrical connections are illustrated in FIG. 3. Alternating current line terminal 156 are connectable through a main switch 158 to the primary winding of a transformer 160 which is desirably of a voltage-stabilizing type to provide a regulated output from its secondary to the variable inductor 162 which may be maunally preset to supply a voltage output, the adjustment being conventionalized as a variable tap 166.

The output is delivered through a normally closed switch 168 (connected in the conventional stop motion elements of the machine) and through a second series switch 170 to the step-down transformer 172 which provides the desired output, at low voltage, to the heating element which is conventionalized in FIG. 3 as a resistor. The switch 170 is closed at the times when energization of the heating element is desired by camming on the main cam drum of the machine.

The heating element is desirably of a nickel-chromium alloy and may be operated through the adjustment described at any temperature suitable for the particular fusible yarn which is used in the knitting of the tab.

Referring to FIGS. 1A and 4, the sinker cap is slotted at 174 to provide a mounting location for the stationary bracket 176. For sinker withdrawal the sinker cam 178 is attached to a radially movable slide 180 which is controlled and set in conventional manner from the main drum camming through the use of Bowden cable 182 and stop screw 184. Referring to FIG. 5 which shows the cam ring layout, prior to introduction of the element 134, shown thereon, over the needle circle, the needles are lowered to welt height by cam 62 and remain at this level until they are elevated by cams 64 and 70.

Referring to FIG. 4, the active end portion of the heating element 134 is shown in active position inward of the needle circle. Shading illustrates the peaks and valleys in the tab fabric 186. Transfer courses, preceding the tab in the order of knitting, are shown at 188, while indicates the inside face of the in-turned welt fabric as it is gathered toward the upper edge, and inwardly into, the fabric receiving tube, the fabric being further indicated at 192.

The fabric tensioning system is in part shown in FIGS. 1A, 1B and 1C. Tubular member 200 replaces the funnelshaped member 220 of said Currier patent. Elongated ports 202 are provided opposite the suction source opening 204 in the cylinder raising tube 205. A clamp ring 206 serves to maintain support and concentricity of the fabric tube 207, as well as providing a closed end for chamber 208. Tubular member 200 is fastened to the clamp ring 206 by screws 210. Tube 200, ring 206, and fabric tube 207 are driven by, and rotate with, the needle cylinder.

A ring 212, fastened to the cylinder raising tube 205 by screws 214, serves as a closed end for chamber 216. Though suction may be applied at required times from ports 202 through chamber 216 to chamber 208, a stationary flanged bushing 218 is supported by ring 212 and serves as a bearing corresponding to 230 of the Currier patent. Fitting 219 and tube 220 correspond to the members 228 and 226, respectively, shown and described in the Currier patent.

Referring next to FIG. 6 which is a diagramamtic illustration of the pneumatic tensioning system, the suction source is represented by a motor-driven centrifugal blower shown at 230. The conventional portion of the system comprises suction tube 232, chamber 234 and fabric-receiving tube 220. After press-off the stocking is delivered to charm her 234. By operation from a main cam drum move, valve 236 is closed and door 237 is opened to drop the stocking into a collecting receptacle.

To provide suction to the welt chamber 208, a branch tube 238 and valve 240 are provided. During the initial part of welt knitting, a main cam drum move effects opening of valve 240 to divide the suction to both the fabricreceiving tube 220 and chamber 208. The setting of valve 240 is adjustable to secure a satisfactory tension on the welt, the adjustment depending upon the Weight of the fabric.

Just prior to transfer, and to avoid hanging up of the fabric on the dial bits, valves 240 and 236 are closed, resulting in no tension being applied to the fabric. The tension is also eliminated by closure of these valves during the knitting of the tab. Immediately after press-off, valve 236 is opened to suck the completed stocking into chamber 234.

In addition to the tcnsioning on the welt by the suction, air under pressure flows through the nozzles 54 and 56 (FIG. 5) to aid in positioning the initial courses of the welt fabric into chamber 208.

In the production of a typical stocking, the operation from makeup to the beginning of the welt is as described in said Currier patent and need not be repeated. During this knitting tension is maintained on the fabric by suction through the tube 220, the valve 236 being open, while the valve 240 is closed.

The welt is begun in the fashion described in said Currier patent, and knitting thereof proceeds as therein described. However, using what has been disclosed, following the initiation of welt knitting both valves 236 and 240 are open and air jets are produced through the nozzles 54 and 56 shown in FIG. 5. The result is that the loop of fabric constituting the turned welt is introduced into and then maintained in proper condition in the region 208. In particular, proper tension is applied to the fabric as it is produced on the needles.

Just before the transfer of loops from the dial elements to the needles is to occur, both valves 236 and 240 are closed by a move of the main cam drum of the machine to interrupt the suction action. The purpose of removing tension just before transfer is to avoid possible hanging up of any portions of the fabric on the transfer elements.

The suction now remains off during the formation of the tab. In the preferred operation the tab is knit two feed either with or without run-resist structure of the type shown and described in said Currier patent. Run-resist structure seems preferable but in view of the raveling resistance afforded by the use of a low melting yarn, the run-resist structure is not too important. The two-feed knitting proceeds as already indicated using yarns at the respective feeds which have relatively higher and relatively lower melting points. Desirably, for complete continuity, nylon of a type used for the knitting of the welt is continued at the main feed. However, at the auxiliary feed there is introduced a yarn of lower melting point such as a lower melting point nylon or a polypropylene yarn as already indicated. The particular nature of the yarn having the lower melting point is not significant so long as this property exists. The only requirement is that by controlled heating the yarn of lower melting point may be softened or completely melted while the main yarn maintains its identity substantially unchanged to avoid complete disintegration of the tab. By this is meant that portion of the tab adjacent to the transfer, since as will be noted, the major portion of the tab may be torn away and discarded to lessen the bulk of what remains.

After a preliminary portion of the tab is knit, cam 178 is inserted to efiect the special sinker withdrawl, and needles are caused to remain low at the region where they pass the heater 134, as already described.

Simultaneously with this, or immediately thereafter, the heater assembly is moved into action causing the element 134 to engage the high portions at least of the tab fabric. As has been mentioned, and as shown in FIG. 4, because of the absence of tensioning, the tab fabric will have a wavy configuration which is particularly advantageous in the operation involved. As the tab nears completion, switch is closed to provide the heavy current through the element 134 to bring it to the desired temperature suitable to the particular yarns which are involved in the tab. Desirably, the knitting machine is also now slowed down to permit heating to be effective. What occurs as the result of the heating is somewhat a mixture of actions. In part the yarn of less melting point may be quite completely fused, in which case it tends to run into the concatinations of loops of the main yarn to act as a matrix locking them together. In other regions the yarn of lower melting point may merely soften to act more or less as an adhesive securing together both loops of the main yarn and loops of itself as well. Due to one or both of these actions, a selvedge is produced which may not be strong but quite suflicient to prevent raveling considering, as mentioned hereafter, the selvedge becomes enclosed in the natural roll of the terminal fabric so as to be quite Well protected against engagements which would produce sufficient raveling to cause a run back into the transfer region.

Following the completion of the tab-forming operation, press-off is effected by withdrawal of the yarns and clearing of all the needles. The valve 236 is then opened (valve 240 remaining closed) with the result that the pressed-off stocking is drawn through the tube 220 into the chamber 234. The knitting may then be immediately resumed by makeup for the next stocking.

From the finished stocking there may be manually torn off the terminal portion of the tab to remove bulk. This may be accomplished, though not necessarily at a definite course, by reason of the weakening of the structure beyond the portion which serves as a selvedge, the tab, as it comes off the machine, being generally perforated at various points and quite weak at others so that this removal is simple. Due to the natural tendency of the tab fabric to curl, the residual portion becomes rolled into a circumferential roll or curl so that the ruff selvedge edge is well hidden and effectively protected against abrasion or other action which might tend to destroy the selvedge and thus permit raveling.

The matter of forming a tab with a selvedge is described for completeness, but it is the subject matter claimed in the copending application of John J. Millar, Ser. No. 680,226, filed Nov. 2, 1967, now abandoned. The tensioning provisions forming the subject matter of the present application may, of course, be used in the formation of turned welts even if the described tabforming method is not used.

I claim:

1. A circular knitting machine comprising a pair of circular substantially coaxial beds, elements, including needles, mounted throughout the circumference of, and for movements in, said beds, devices cooperating with said elements, for their operation and the formation of stitches, elements mounted in a first one of said beds being arranged to hold a tubular knitted portion of fabric during further rotary knitting of tubular fabric by elements mounted in the other of said beds, means for effecting transfer of loops from the elements of the first bed to the elements of the other bed to form a closed loop of fabric, and tensioning means, said tensioning means comprising means providing a first chamber for the reception of fabric knitted prior to said closed loop, means providing a second chamber for reception of fabric during the formation of said closed loop, and means for applying suction selectively to said chambers.

2. A knitting machine according to claim 1 in which the second bed is a needle cylinder and in which said chambers are respecitvely provided interiorly and exteriorly of a tubular member located within said cylinder.

3. A circular knitting machine according to-c1aim 1 in which controlling means is provided to control selectively suction to the first of said chambers, suction simultaneously to both of said chambers, and no suction to either of said chambers so that, in the last case, knitting may proceed without suction tension on fabric.

4. A knitting machine according to claim 3 in which the control means applies suction to only the first of said chambers to remove a knitted product following press-off.

References Cited UNITED STATES PATENTS 2,636,364 4/1953 Moss 66-41 3,159,015 12/1964 Moretta. 3,273,360 9/1966 Mahler, 2,747,390 5/ 1956 Reymes-Cole .66-173 3,340,706 9/ 1967 Currier 6695 XR FOREIGN PATENTS 570,628 2/1957 Canada. 1,040,384 8/1966 Great Britain. 1,047,123 11/1966 Great Britain. 1,055,701 1/1967 Great Britain.

WM. CARTER REYNOLDS, Primary Examiner US. Cl. X.R. 66149

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