US2932182A - Knitting machine - Google Patents

Description

April 12, 1960 Filed July 15. 1955 R. H. LAWSON 2,932,182

KNITTING MACHINE 4 Sheets-Sheet l INVENTOR.

OBERT H. LAWSON FIG. I. a 'h u ATTORNEYS April 12, 1960.

R. H. LAWSON 2,932,182 KNITTING MACHINE Filed July 15. 1955 4 Sheets-Sheet 2 F I G. 8.

INVENTOR. FBOBERT H. LAWSON ATTORNEYS R. H. LAWSON 2,932,182

KNITTING MACHINE April 12, 1960 Filed July 15. 1955 4 Sheets-Sheet 3 avy FIG. 6.

F 6' 5 INVENTOR.

ROBERT H. LAWSON ATTORNEYS April 12, 1960 R. H. LAWSON I 2,932,182

" KNITTING MACHINE Filed July 15. 1955 4 Sheets-Sheet 4 INVENTOR. BOBERT H. LAWSON ATTORNEYS 2,932,182 KNITTING MACHINE Robert H. Lawson, Pawtucket, R.I., assignor to Scott & Williams, Incorporated, Laconia, N.H., a corporation of Massachusetts Application July 15, 1955, Serial No. 522,226 6 Claims. (Cl. 66-153) This invention relates to knitting machines and has particular reference to takeup or tensioning means for stockings started on bare needles.

In.- my Patents Nos. 2,625,026 and 2,709,352, dated, respectively, January 13, 1953- and May 31, 1955, there are disclosed takeup or tensioning devices for circular stocking knitting machines which are arranged to grab the initial portion of a stocking started on bare needles to impart uniform tension thereto during the knitting of the leg and foot portions thereof to secure uniformity of stitches. A disadvantage of the type of takeup shown in said patents is that a considerable amount of vertical space is required for the taking up and tensioning of full length ladies stockings, requiring the machine to which it is applied to have its needle cylinder and associated mechanism substantially raised with the result that an operator must work from a platform in making adjustments in the vicinity of the top of the needle cylinder.

It is the general object of the present invention to provide a takeup of simple and compact construction which will grab the initial portion of a stocking and then apply tension at desired times thereto in proper and uniform fashion.

A further object of the invention is the provision of a stop motion device which will effect stoppage of the machine in the event of misoperation of the takeup mechanism and before damage occurs or before such entanglement of fabric'takes place as would require considerable effort in putting the machine back into operation.

The foregoing and other objects of the invention, particularly relating to details of construction and operation,

will become apparent from the following description read in conjunction with the accompanying drawings, in which: i v

Figure 1 is a fragmentary sectional view taken through the upper portion of a circular knitting machine of revolving cylinder type to which the invention is applied; Figure 2 is an enlargement of the upper portion of Figure l to show details; I

Figure 3 is a plan view showing certain of the takeup elements located adjacent to the upper end of the needle cylinder, with certain elements omitted for clarity;

Figure 4 is a diagrammatic section and elevation showing mechanism for taking the takeup out of action at desired times;

Figure 5 is an elevation, Figure 6 is a vertical section,

and Figure 7 is a planview showing a bracket used for the support of takeup rolls;

Figure 8 is a plan view showing the fabric guide for directing the welt of a stocking to takeup rolls;

Figure 9 is a fragmentary elevation showing, in particular, certain stop motion elements associated with a takeup roll;

Figure 10 is an elevation looking at the right of Figure 9; and t Figure 11 is a sectional view showing'the fashion in which certain electrical connections for thestop motion are made.

Considering first Figures 1 to 8, inclusive, which to avoid complexity do not show the stop motion hereafter described, there are indicated therein only such parts of a conventional circular knitting machine as are more or less directly concerned with the present invention, it heing understood that the machine is of the revolving cylincler type arranged to knit sheer ladies hosiery and, as illustrated, adapted to provide turned welts on the stockings, each stocking being started on bare needles and being cast ofi when completed. Such machines are well known in the trade and the conventional aspects of operation will, therefore, be omitted.

The rotary needle cylinder of the machine is indicated at 2 and is provided with axiallyextending slots for the reception .of latch needles 4, intermediate jacks 6, and

pattern jacks 8, the latter being of the type provided with selectively removable butts (not shown) for the formation of mesh or similar fabric. As will appear, the invention is applicable to many types of machines, and it will be understood that specific reference to a machine herein is not to be regarded as limiting the applicability of the invention. Also shown is the conventional dial 10 provided with stitch holding elements 12 cooperating with the needles in the formation of a turned welt by holding the stitches initially formed during the knitting of the welt fabric, the stitches being thereafter retransferred to the needles prior to initiation of the knitting of the leg fabric. The dial cap is indicated at 14 and associated therewith is an air tube 16 through which air is directed downwardly through holes 18 in the dial so as to force downwardly the fabric of the welt for grip ping by the takeup.

Details of such action and control are described in my patents mentioned above. In the present instance, a sheet metal welt fabric guide is provided at 20 and is supported by the sinker dial 22. The guide 20 is funnelshaped having a generally circular upper portion merging to an outlet 24 of generally elliptical shape and serving to flatten out to some extent the welt fabric under the action of the air blast delivered from tube 16. As will appear, this flattening action serves to position the welt fabric for engagement by takeup rolls.

The needle cylinder 2 is provided with the usual interiorkeyway 26 for the reception of a key 28 secured to the cylindrical shank 30 of the conventional sleeve 1 gear 32 which, as is conventional, is provided with bevel gear teeth for the drive of the needle cylinder. The gear 32 is fixed against axial movement but receives slidablev axial adjustments of the needle cylinder for the usual stitch quality control. By such means, the lengths of the stitches are adjusted by varying the paths of the needles with respect to the cooperating sinkers, the needle controlling cams being fixed whereas the sinkers are moved axially with the needle cylinder. While the tube 40 thus moves axially during operation of the machine, from the standpoint of operations hereafter described it may be assumed to be essentially axially fixed since its actual movements are slight in comparison with those which are involved in the takeup elements.

In the upper portion of the keyway 26 and resting on the key 28 there is a key 42 which projects inwardly into a keyway in a cylindrical member 44 which is free to move vertically with respect to the needle cylinder but is Patented Apr. 12, 1960 its lower end as indicated at 46, and threaded into its upper end is a ring 48 which supports a pair of brackets 50 at diametrically opposite points. The brackets 50 support duplicate elements which will now be described.

Each bracket 50 carries a pin 52 on which there is pivotally mounted a movable bracket 54 the construction of which will be clear from Figures 5, 6 and 7'. The bracket 54 is provided with an extended lower portion 56 at the ends of which are arms 58 providing for the mounting of trunnions 60 provided in the ends of a mandrel 62 which is conveniently formed of gear stock and serves to carry thereon a series of rubber discs 64 which are spaced as indicated most clearly at the right of Figure 3. Springs 66 which may be of light construction serve to rock the brackets 54 so as to hold toward contact the discs 64 carried by the respective brackets. Between the discs 64 there project fingers 68 secured in the brackets 54, these fingers serving to guide the fabric away: from the surfaces of the members 62 between gripping surfaces 64 of the rolls to prevent especially the start of the fabric from winding thereon. The various discs 64 serve as rollers for the gripping and tensioning of the fabric as it is being knit.

Meshing with the central portion of each gear-type mandrel 62 is a gear 70 mounted on the corresponding pin 52. These gears mesh with internal worm threads 72 provided in the upper end of a cylindrical member 74 which is provided with a shoulder which may rest on flange 46 and hasa depending extension 76- secured at 78 to a sleeve 80 which extends downwardly through the shankStt of sleeve gear 32 and past. and'beyondthe thrust bearing 38 into the upper portion of tube 40. Near its lower end the tube 80 carries a bearing ring 82 with which engage rollers 84 carried by the arms of a forked lever 86 which extends through a clearance opening 88 in the tube 40 and is supported on a fixed" pivot pin 90 and is provided with a follower roller 92 arranged for engagement by suitably located cams 94 on the main cam drum 96 of the machine. Counterweights such as indicated at 98 may be replaceably secured to. the lever 86' tothe left of its pivot as viewed in Figure 4.

Above the disc 32 the tube 80. is. provided with a conis cal clutch element arranged to cooperate. with a conical clutch element 102 carried by the tube 40, they two clutch elements being provided with respective friction facings indicated at 104 and 106.

Mounted on the outside of tube 80 by slotted. engagement on pins 112 and 114 is a slide110 urged yieldingly upwardly by a spring 1 16. When tube 80 is moved upwardly the slide 110 may engage within one or more notches 118 formed in the interior of. gear 32 so as to constrain tube 80 to rotate with the gear and needle cylinder. The possibility of yielding against the action of spring 116 prevents breakage if, when the tube 80 is raised a notch 118 is not aligned with the slide.

The operation of the takeup arrangement may'now bedescribed.

Following the press-off of the final stitches of a stocking, that stocking will be removed by the action of the: takeup rollers as will be described hereafter. Before its complete removal a new stocking'maybe started, and this is accomplished by the feeding of yarn, to needles inlconw ventional fashion. Following the starting, stitches. aretransferred in the usual way to the elements 12 in the dial and then the knitting of the welt is continued in c0,nventional fashion. As the loop of welt fabric is being formed, air is desirably delivered through the tube- 16 to smooth out and keep under controlthis welt fabric which is gradually driven downwardly in the guide 20 toward and through the opening'24. Before, the fabric reaches the grab rollers, the motion of these rollers will be at.- rested by the action of one of the earns. 94 on lever 86 to. raise. the; tube 80. s s to i eng ge the l tch. f c 104. and 1,06. The tube 80, then rotates with the needle cylinder, being locked thereto by the engagement ofthe 4 upper end of slide '110 in a receiving notch 118 of the sleeve gear 32. The worm threads 72 thus rotate with the assembly of the takeup rolls and gears 70 so that no rotation of the rolls occurs.

At the completion of the welt, the stitches are transferred from the elements 12 back to the needles and knitting of the shadow welt or upper end of the leg is begun in conventional fashion. At this time, it is desirable to initiate the imparting of tension to the fabric while it is being knit and operation accordingly proceeds as follows:

The loop of welt fabric will now, due to the action of the air. blast, be in engagement with the takeup rolls adjacent to the region of their contact under the action of springs 66. Roller 92 is nowreleased by the cam 94 which previously engaged it, and, consequently, the tube 80 will drop to produce engagement of the clutch faces 104 and 106. At the same time, the slide 110 is'released from the notch 118. The tube 80 is accordingly brought to rest, bringing to rest the worm threads 72 so that as the cylinder revolves carrying with it the gears 70 these are caused to rotate by engagement with the worm threads in the directions indicated by the arrows in Figure 2. The takeup rolls are thus driven to engage and pull downwardly the welt fabric. This action now occurs at a maximum rate which is substantially in excess of the rate at which fabric is being formed, and, consequently, there is quickly'attained a condition of application of tension to the fabric at the needles. It may be noted that in this action of drawing down and tensioning the fabric a torque is imparted by the engagement of the rolls with the fabric about each of the pins 52, causing the brackets 54 to rock inwardly to pinch more tightly the fabric between the rolls. The springs 66 accordingly may be. made quite light and play no substantial part after tensioning begins in maintaining the pressure of the rolls against the fabric. As the tension exerted on the fabric increases; there is reached the condition at which the reaction of the gears 70 on the worm threads 72 will serve to urge these threads upwardly so as to raise the tube to disengage the clutch faces 104 and 106. The result is slippage, with some friction, of the. clutch faces. relative to each other so that the tube 80 and its associated parts, including the worm threads 72, will be rotated in the direction of rotation of the needle cylinder but at an average lower rate with the result that the rolls will be rotated on their axes at a rate corresponding to the rate of formation of fabric and consistent with the. maintenance of a substantially constant tension of the stitches on the needles. The tension actually existing on the average is essentially that of the unbalanced weight.

of. the entire. assembly including the tube 80, member 74,. member 44, the rolls, brackets and other associated parts. By reference to the unbalanced weight there is.

included. the balancing action due to such weight as may be applied at 98 to the lever 86 which serves, in part, to counterbalance the weight of this assembly. Assuming, that without a weight 98 the tension applied would be the maximum ever desired inuse, it will be evident that one, or more weights may be added at 98 to secure any desired amount of tension on the fabric as it is being knit. The actual operation may be somewhat intermittent, i.e. the rotation of the tube 80 and the associated takeup parts, may not be uniform; but the elasticity of the fabric extending between the takeup rolls and the needles will serve to compensatejto the extent that the tension at the needles, which is the point of importance, will be substantially uniform throughout the operation.

While the reaction of the gears 70 on the worm threads 72 has been referred to, it will be noted that inv part the. raising, action on tube 80may be, due to the fact that the rolls tend to climb the fabric, resulting in rise of the flange 46 to tend to lift the member 74. Dueto this auxiliary action, there is not produced what might'he regarded as a sustantial wedging action of the teeth of a the gears 7 on the worm threads 72 with attendant substantial friction. An equilibrium situation results in which, as before stated, the tension on the fabric is maintained in substantial correspondence with the unbalanced Weight of the takeup assembly. A smooth action accordingly ensues.

It will now be evident that the relatively slight vertical adjusting movements which may be imparted to the tube 40 for control of stitches will have no effect on the takeup action. If the tube 40 is slightly raised, this means only that the takeup assembly will move slightly higher in releasing the clutch faces 104 and 106. Accordingly, as previously stated, the tube 40 may be regarded, in effect, as stationary.

At the times of formation of the heel and toe, the tension exerted by the takeup should be removed, and this is accomplished merely by the action of cams such as 94 on the main cam drum effecting rise of the tube 80 to such extent as to disengage the clutch faces 104 and 106 and cause slide 110 to engage within notch 118 so that the tube 80 and its associated parts will rotate with the needle cylinder at the full speed thereof. Following these pocket formations, the tensioning operation is reinstated by release of lever 86.

At the end of the loopers rounds, prior to press-off, the tension is again desirably released by the action of a cam 94 to permit press-off to occur smoothly and without danger of engagement of loops by the needles. After press-off occurs, the lever 86 is again released whereupon clutching occurs between faces 104 and 106. Since now no retarding tension is exerted on the rolls, the tube 80 is brought completely to rest with the consequence that as the needle cylinder continues to revolve the rolls operate at maximum speed to draw off the end of the stocking. During this final draw-off operation the beginning of another stocking may occur and the draw-off operation of the rolls may be continued so long as the amount of welt fabric knitted is insufficient to cause it to reach the position of roll contact. Prior to the possibility of this occurrence, the feeding action of the rolls is interrupted by the action of a-cam 94.

The stocking after final release from the rolls will drop into the lower end of the tube 40 or into a continuation thereof and may be driven outwardly to a receptacle through the use of an air blast as described in my Patent No. 2,625,026, referred to above.

The members 68 projecting between the discs 64 serve to guide therefrom any portions of the fabric tending to wind about the rolls. However, to insure against the possibility of fabric winding around the rolls as might occur from loose threads in case of a hole caused by a partial press-off, it is desirable to provide a stop motion arrangement such as will now be described.

Reference may be made to Figures 9, 10 and 11 which show particularly the stop motion devices which, for clarity, were omitted from the figures previously discussed.

The elements of the machine are electrically grounded from the standpoint of stop motion operation. Each of the takeup roll brackets 54 is provided with a member 120, secured thereto, having fingers 122 of flexible type, and desirably silver-plated projecting upwardly and between the stripping members 68 and closely approaching the peripheries of the discs 64. The fingers 122 are slightly spaced from a rod 124 secured in insulating carriers 126 carried by the brackets 54. These rods 124 are also desirably silver-plated to prevent corrosion and secure good electrical contacts. Each rod 124 is electrically connected by an insulated lead 128 to a member 130 of flexible metal carried by an insulating block 132 secured to a bracket 54 and having a flexible contact brush 134 engageable with a conducting ring 136 mounted, with interposition of insulation 138, on the interior of the member 74. In view of the fact that the brackets 54 swing, it is desirable to have the upper surthe brackets 54. The ring. 136 provides contact through- 360 to take care of the relative rotation of member 74 and the rolls about the axis of the needle cylinder.

An insulated conductor 140 connects the ring 136 to an insulated stud assembly 142' (Figure 11) which mounts a flexible contact member 144 engaging a pin 146 which is urged outwardly by a spring 148, the pin being insulated from its mounting. The pin engages, as a brush, a ring 152 mounted, with interposition of insulation 154, in the tube 40. An insulated conductor 156 extends through an opening in the tube and connects the ring 152 to the conventional stop motion which need notbe described except to say that the closure of the circuit from conductor 156 to ground will effect itsoperation to stop the machine. one which, as is usual in these machines, effects stoppage in the event of yarn breakage, pile-up of stitches, or other accidental occurrences which might produce damage if the machine continued to run.

If, despite the action of the stripping fingers 68, some fabric tended to wind about one or the other of the takeup rolls, engagement of one of the flexible fingers 122 would occur causing it to be flexed to engage the pin 124 to ground the stop motion circuit and thus stop the machine. There is a possibility that this might occur in the event that a large hole accidentally appeared in the stocking fabric, or in the case of passage of such loose portions of the fabric as heel and toe pockets. Ordi:

narily, however, the members 68 will strip such portions.

of the fabric from the rolls directing them properly downwardly.

It will be evident from the foregoing that there is provided a takeup arrangement capable of providing proper tension to a fabric such as, in particular, the sheer fabric forming the leg and foot portions of ladys stocking wherein the maintenance of predetermined uniform tension is highly desirable to secure uniformity of stitch production. This end is accomplished, furthermore, without requiring excessive space beneath the needle cylinder so that the takeup may be incorporated in machines of standard type without necessitating the raising of the level of the needle cylinder. Furthermore, the takeup may be applied to presently unequipped machines of this type with very little change in their mechanisms and with;

out interference with portions. of the mechanism used for normal purposes. It will be evident that various changes may be made in details of the invention without departing from the scope thereof as defined in the following claims.

What is claimed is:

1. In a knitting machine comprising a needle cylinder, needles carried thereby, and associated elements arranged for the knitting of separate fabric articles starting on bare needles, fabric takeup means comprising an assembly movable axially of the needle cylinder and comprising cyclically operating gripping means adapted to grip fabric during the knitting thereof, said gripping means being located within the needle cylinder'adjacent to the stitch drawing ends of the needles, and means comprising a threaded element coaxial with the needle cylinder movable relatively to the needle cylinder to effect drive of said gripping means, and means controlled by axial movement of said assembly to effect alterna tively either a stationary condition of the last mentioned means relatively to the needle cylinder to produce interruption of drive of said gripping means or relative rotation'of the last mentioned means relatively to the needle cylinder to produce drive of said gripping means.

2. In a knitting machine comprising a needle cylinder, needles carried thereby, and associated elements arranged for the knitting of separate fabric articles starting on bare needles, fabric takeup means comprising The stop motion used may be the samev cyclically operating gripping means adapted to grip fabric during the knitting thereof, said gripping means being located within the needle cylinder adjacent to the stitch drawing ends of the needles, means having relative movement with respect to the needle cylinder to effect drive of said gripping means, stop motion devices operable by fabric winding. about said gripping means, said stop motion devices comprising electrical contact elements movable by the fabric winding about said gripping means, and brush and ring elements providing electrical connection to said stop motion devices.

, 3. In aknitting machine comprising a needle cylinder, needles carried thereby, and associated elements arranged for the knitting of separate fabric articles starting on bare needles, fabric takeup means comprising an assembly movable axially of the needle cylinder to impart by its weight a substantially constant tension to the fabric and comprising cyclically operating gripping means adapted to grip and feed fabric progressively therethrough during the knitting thereof, said gripping means being located within the needle cylinder constantly adjacent to the stitch drawing ends of the needles, and means for stopping the cyclical operation of said gripping means during the knitting of a predetermined portion of an article.

4. In a knitting machine comprising a needle cylinder, needles carried thereby, and associated elements arranged for the knitting of separate fabric articles starting on bare needles, fabric takeup means comprising an assembly: movable axially of the needle cylinder and comprising cyclically operating gripping means adapted to grip fabric during the. knitting thereof, said gripping means being located within the needle cylinder adjacent to the stitch drawing ends of the needles, and means having relative movement with respect to the needle cylinder about. its axis to eifect drive of said gripping means,

means controlled by axial movement of said assembly to effect alternatively either a stationary condition of the last mentioned means relatively to the needle cylinder to produce interruption of drive of said gripping means or relative rotation of the last mentioned means relatively to the needle cylinder about its axis to produce. drive of said gripping means, and means for stopping the takeup action of the gripping means during the knitting of a predetermined portion of an article. 5. In a knitting machine comprising a rotary needle cylinder, needles carried thereby, and associated elements arranged for the knitting of separate fabric articles starting on bare needles, fabric takeup means comprising an assembly movable axially of the needle cylinder and comprising cyclically operating gripping means adapted to grip fabric during the knitting thereof, said gripping means being located within the needle cylinder adjacent to the stitch drawing ends of the needles and means having relative movement with respect to the needle cylinder about its axis to effect drive of said gripping means, means controlled by aXial movement of said assembly to effect alternatively either a stationary condition of the last mentioned means relatively to the needle cylinder to produce interruption of drive of said gripping means or relative rotation of the last mentioned means relatively to the needle cylinder about its axis to produce drive of said gripping means, and means for stopping the takeup action of the gripping means during the knitting of a predetermined portion of an article.

6. In a knitting machine comprising a needle cylinder, needles carried thereby, and associated elements arranged for the knitting of separate fabric articles starting. on bare needles, fabric takeup means comprising cyclically operating gripping means adapted to grip fabric during the knitting thereof, said gripping means being located within the needle cylinder adjacent to the stitch drawing ends of the needles, means having relative movement with respect to the needle cylinder about its axis to effect drive of said gripping means, means providing an: air blast for moving the fabric into position for engagement by said gripping means, and means for stopping the takeup action of the gripping means during the knitting of a predetermined portion of an article.

References Cited in the file of this patent UNITED STATES PATENTS 799,081. Obenhoff et al Sept. 12, 1905 980,826 Obenhofl. et al. Jan. 3, 1911 1,259,478 Bechtel Mar. 19, 1918 1,550,056 Barth Aug. 18, 1925 1,825,370 Smith Sept. 29, 1931 2,003,774 Gruna et al. June 4, 1935 2,644,325 Hanes et al. July 7, 1953 2,694,304 Butler Nov.16, 1954 2,709,352 Lawson May 31, 1955 2,799,149 Minton et al. July 16, 1957

Images