US3380266A - Attachment for circular knitting machine - Google Patents

Description

April 30, 1968 A. J. WILLIAMSON ETAL 3,380,256

ATTACHMENT FOR CIRCULAR KNITTING MACHINE Filed Oct. 24, 1965 3 Sheets$heet 1 ANDREW JOHN WILLIAMSON, WILLIAM PORTER CHESNUTT,JR.

BYA%% INVENTORS,

A ril 30, 1968 A. J. WILLIAMSON ETAL ATTACHMENT FOR CIRCULAR KNITTING MACHINE Filed Oct. 24, 1965 Sheets-Sheet 2 a I IIIIIIIIIIII I 'f\ I W22 v f ,4? FIG. 2

I a 2/ IN/4 4 I I i NI I 4? I WI I I I w 7 I W I g .y I \E/ I I k\\ /7 I I mg I V zai' 44/? I T g i; T 5 I 5' I Z5 27 I I I; I

2a; II ,50 33 if X I 4 7 4 =1 4 1 L 35 INVENTORS T 0 ANDREW JOHN WILLIAMSON,

\l 1 :3 WILLIAM PORTER CHESNUTRJRL W I I .42

\\\\ O O I\\\ April 30, 1968 A. J. WILLIAMSON ETAL 3,330,266

ATTACHMENT FOR CIRCULAR KNITTING MACHINE 3 Sheets-Sheet 5 Filed Oct. 24, 1965 wwm I mw INVENTORS ANDREW JOHN WILLIAMSON, WILLIAM PORTER CHESNUTT, JR.

BY ATTOJP/VE/ United States Patent 3,380,266 ATTACHIVIENT FOR CIRCULAR KNITTING MACHINE Andrew John Williamson, 213 Circle Drive, SW., and William Porter Chesnutt, Jr., 503 Linden Circle, NE., both of Athens, Tenn. 37303 Filed Oct. 24, 1965, Ser. No. 504,656 1 Claim. (Cl. 66150) ABSTRACT OF THE DISCLOSURE The present disclosure describes a pull down mechanism for a circular knitting machine, causing the stitches to be pulled down from the sinkers, minimizing the possibility of the formation of irregular or skipped stitches or the like. The knitting machine is provided with a delivery cylinder which carries an upwardly outwardly flaring portion having a plurality of spaced vertically extending shed bars.

This invention relates to a circular knitting machine, and more particularly to a fabric pull down mechanism for a circular knitting machine.

Still more particularly, this invention relates to a circular knitting machine having a fabric pull down attachment to assure that stitches will be pulled from the sinkers, thereby to minimize the posibility of the formation of irregular or skip stitches, jams or the like.

This invention further relates to a pull down attach ment for a conventional circular knitting machine for assuring a steady, progressive feed of the fabric which has been knitted, which feed is independent of the length or weight of the knitted increment.

The invention further relates to a knitting machine device having a novel shedding attachment to assure uniform tension of the knitted fabric as the stitches are formed.

Accordingly, it is an object of this invention to provide an improved circular knitting machine and attachment therefor.

A further object of the invention is to provide a dependable and automatic mechanism for assuring a continuous and progressive feed of knitted fabric through the cylinder of a conventional circular knitting machine, whereby there is no tendency for the stitches to hang on the sinkers and the tension on the fabric at the knitting station is at all times uniform, to assure the formation of stitches of a desired size, independent of the weight of the fabric which has been formed and fed through the throat of the knitting machine.

To attain these objects and such further objects as may appear herein or be hereinafter pointed out, reference is made to the accompanying drawings, forming a part hereof, in which:

FIGURE 1 is a perspective view of a needle cylinder and associated mechanism including the attachment of the present invention, with certain parts of the knitting device being omitted for clarity.

FIGURE 2 is a magnified vertical section taken on the line 22 of FIGURE 1;

FIGURE 3 is a schematic developed view of the cam track operating the pull down device;

FIGURE 4 is a horizontal section taken on the line 44 of FIGURE 2;

FIGURE 5 is a horizontal section taken on the line 5-5 of FIGURE 2.

In accordance with the invention, 10 represents a conventional cylinder of a circular knitting machine, the illustrated cylinder being of the type frequently employed for the fabrication of hosiery or the like. While the present invention is illustrated in conjunction with a cylinder of this type, it will be readily recognized that the invention is not limited in its use to hosiery knitting machines.

Since the knitting machine proper is in all respects conventional, the present invention residing solely in the pull down attachment and its combination with the knitting machine, only an abbreviated description of the standard knitting machine components Will be undertaken.

The cylinder 10 includes the usual vertical slots 11, slidably supporting the needles 12 (see FIGURE 2). In the usual manner, the upper edge of the cylinder 10 is formed with radially directed sinker guide slots 13, within which the sinkers 14 are radially slidably carried. Sinker guide ring 15 is movably mounted on the upper end of the cylinder 10 and incorporates the usual sinker control mechanism for effecting the inward and outward radial movement of the sinkers 14 in timed relation to the upward and downward movement of the needles 12 for the formation of the stitches which comprise the fabric.

It will be understood that the mechanism for actuating the sinker guide ring 15 through the control bracket 16 has been omitted from the drawings, for simplicity. Similarly, it will be understood that the drawings do not include the conventional yarn feed fingers which are normally located at the knitting station S.

The knitting cylinder 10, at a lower portion thereof, is provided with a drive gear portion 17 for engagement with the usual cylinder drive mechanism.

In accordance with the invention, a delivery cylinder 20 is co-axially disposed within the knitting cylinder 10,

' the upper end 21 of the delivery cylinder being provided with an outwardly flaring receiver portion 22, the receiver portion being disposed adjacent the throat area T of the knitting cylinder. As best seen from FIGURE 2, the receiver portion 22 comprises generally an inwardly tapered annulus defined by the annular wall portion 23. The delivery cylinder is provided with a plurality of vertically directed slots 24, which slots house and guide the shed bars 25, next to be described, for vertical reciprocatory movement within the delivery cylinder.

The shed bars 25 are generally flat in cross-section and include elongated body portions 26, slidably received within the slots 24. The body portion 26 of the shed bar is recessed, as at 27, to define a rectangular cutout, said cutout including a vertically extended slide portion 28.

The delivery cylinder 20 includes an annular portion 29 having an inwardly directed flat surface 30 hearing against slide portions 28 of the shed bars, to guide the latter against canting during vertical shifting movement within the cylinder.

The upper ends 31 of the shed bars are bent outwardly to conform to the inclination of the annulus 23 at the upper end of the delivery cylinder and, as Will be seen from FIGURE 2, in the lowered position of the shed bars, the upper end portions lie substantially flat against this annular surface. The lowermost ends 32 of the shed bars are directed radially outwardly, projecting beyond the delivery cylinder.

A collar 33 is made fast, as by bolts 34, to the lower end of the delivery cylinder, the collar including vertical slots 35 through which project the radially extending portions 32 of the shed bars 25.

The shed bars are biased to a normally downward position by an annular garter spring 36, which may comprise a single annular member or a plurality of individual coil springs, or any other suitable arrangement for downwardly biasing the portions 32 of the shed bars. In the illustrated embodiment, the spring 36 outwardly laps the surface of the collar 33, the spring being fastened to the collar at spaced portions 37 by bolts or other suitable fasteners.

The points 37 are located at a level below the normal lowermost position to be occupied by the projecting portions 32. of the shed bars, so that a downward biasing force will always be exerted against these portions by the spring. The spring 36 is disposed over the upper surface 32a of the projecting portion 32, said portion 32 being preferably provided with a retaining pin 38 to maintain the spring in the desired position.

The upward and downward reciprocating movement of the shed bars is effected by an annular cam member 39 which surrounds the rotating delivery cylinder and which bears against the under surface 32b of the radially projecting portions 32 of the shed bars. The annular cam 39 is generally cylindrical in conformation and includes an upwardly directed riser or tooth portion 40 (see FIG- URES 2, 3, 4) and an extended flat or dwell portion 41.

In operation, the cam remains in fixed position while the delivery cylinder rotates. To block the cam against rotation with the delivery cylinder, the cam is provided with an offset finger 42, including a downwardly directed end portion, which portion lies in the path of a stop 43, made fast to some portion of the base plate or frame of the knitting machine. Optionally but preferably, the position of the stop 43 may be varied so as to vary the position of the tooth 40 with relation to the fixed knitting station S, so that the timing of the lift and drop of the shed bars may be carefully and adjustably coordinated with the other knitting operations.

While in the illustrated embodiment, the cam 39 is shown to have only one rise portion 40, it will be readily understood by those skilled in the art that more such portions may be provided, preferably in accordance with the number of knitting stations.

Each of the shed bars is provided substantially throughout its entire length with a series of gripper means for the tubular knitted fabric, for advancing the same downwardly through the delivery cylinder. In the illustrated embodiment, these gripper means comprise short pointed barbs 44, spaced along the length of the shed bars, each of said bars being provided with a series of barbs 44a in the area of the throat portion.

The barbs are directed both radially inwardly and downwardly, and it will be evident from this orientation that as the shed bars are moved downwardly, the barbs will engage the fabric and draw the same downwardly an increment which is dependent upon the throw or extent of the downward movement of the bars. Since the fabric is tensioned by the downward movement of the bars, the barbs will not be released from the fabric while the bars remain in downward position, ie as they traverse the dwell portion 41 of the cam. However, by reason of the downward inclination of the barbs, they will be released from the fabric immediately as the shed bars are raised by the cam tooth 40.

The operation of the device will be evident from the preceding description. The knitting cylinder 10, carrying the knitting needles and sinkers, is rotated in the usual manner, with the knitting needles and sinkers being selectively shifted inwardly and outwardly adjacent the knitting station S by the usual needle and sinker cams to knit the fabric. As the cylinder 10 and the connected delivery cylinder 20 are rotated, the tubular knitted fabric is fed through the throat area T and into the interior of the delivery cylinder. As the delivery cylinder 20 is rotated, the lower or follower surface 32b of the extensions of the shed bars are progressively wiped over the upwardly di- 4 rected surface of the annular cam 39. The spring 36 assures that such follower portion will be in constant contact with the said cam surface.

In FIGURE 2, the righthandmost shed bar is depicted in its downwardmost position against the flat or dwell portion 41 of the cam 39, whereas the lefthandrnost shed bar is disclosed in an elevated position atop the tooth 40 of the cam.

As will be best seen from the developed view of FIG- URE 3, all the shed bars but one, in the illustrated embodiment, are disposed generally at the elongated dwell portion 41, whereas a single shed bar is shown at the apex of the tooth 40. Under ordinary circumstances, it will be preferred to so coordinate the position of the tooth and, hence, of the shed bars, that the bars are lifted just prior to entering the knitting station S and are lowered directly after passing said knitting station.

As will be readily recognized, the position of the tooth 40- with respect to the knitting station may be varied merely by releasing and readjusting the position of the stop 43, which is fixed with respect to the roating delivery cylinder.

While the primary utility of the device will be realized when the shed bars descend immediately after passing the knitting station, thus assuring that the loops will be completely shed from the sinkers, it will be understood that the positioning of the cam may be employed in a variety of ways, for instance as a means for pre-tensioning the fabric during the formation of loops, thus to control the size of the loops.

From the foregoing description, it will be evident that the device assures a continuous, even fiow of fabric knitted at a knitting station or stations, downwardly through a delivery cylinder.

The shed bars act positively to urge the knitted fabric downwardly, thereby assuring that the same will be shed from the sinkers.

The adjustability of the cam mechanism to permit facile variation of the timing of action of the shed bars may, in addition, be used to vary the knitted texture, as desired, and to assure optimum operation of the device.

We claim:

1. In a circular knitting machine of the type which includes a needle cylinder having a top throat portion rotatable about a vertical axis and carrying vertically movable needles, sinkers mounted between said needles for movement toward and away from the axis of said cylinder, the movement of said needles andsinkers being coordinated as said cylinder is rotated past a knitting station, thereby to form stitches at a throat area of said cylinder, a feed apparatus comprising a delivery cylinder concentrically positioned within said needle cylinder, said delivery cylinder including an enlarged upwardly flaring neck portion adjacent said throat area, vertical guide means formed on the interior sides of said delivery cylinder, vertical rectangular cross-section shed bars mounted on said guide means for vertical reciprocatory movement relative to said delivery cylinder between raised and lowered positions, said shed bars including downwardly and inwardly sloped portions in the area of said enlarged neck portion, inwardly and downwardly directed gripper means formed on said bars for gripping fabric in said throat area and delivery cylinder during downward movement and in the lowered position of said bars, and releasing said fabric as said bars move from lowered to raised position, cam follower portions on said shed bars and stationary cam means positioned to engage and vertically reciprocate said follower portions, said cam means and follower portions being coordinated to locate said shed bars in raised position just prior to said knitting station and to locate said bars in lowered position when said bars are roated past said station, said delivery cylinder at its lower end being provided with a circular collar and said shed bars being provided with outwardly extending radially projecting portions and a circular spring extending around and above said portions below said collar and retaining pins extend- 808,784 1/ 1906' Steber 66150 ing upwardly from said outwardly extending portions to 920,671 5/1909 Scott et a1 66 150 hold said spring in position. 2,3 5, 98 4/1944 Bromley et al 66-150 3,003,342 10/1961 Kent et a1. 66150 References Cited 5 UNITED STATES PATENTS FOREIGN PATENTS 433,251 7/1890 Meir 66-150 8781161 9/1942 France 751,213 2/1904 Steber 66150 801,930 10/1905 Steber 66-450 W. CARTER REYNOLDS, Primary Examiner.

Images