US2784579A - Transfer bit dial construction for circular knitting machines - Google Patents

Description

March 12, 1957 2,784,579

W. LARK] TRANSFER BIT DIAL CONSTRUCTION FOR CIRCULAR KNITTING MACHINES Filed March 18, 1955 PRIO'R lf/ lllllHlII lll!lll I lulu: Null] I llllul I |u|J [I] I] f5 5 h T 7W'W TRANSFER BIT DIAL CONSTRUCTION FOR CIRCULAR KNITTING MACHINES Application March 18, 1955, Serial No. 495,261

3 Claims. (Cl. 66-41) This invention relates to circular knitting machines and more particularly to hosiery machines of the type adapted for automatic formation of a turned welt.

Machines of this type may comprise the conventional needle cylinder, and a dial for transfer bits normally located at the top of and operating on the same axial center as the cylinder. As normal knitting progresses in a machine of this type, the fabric passes to the interior of the needle cylinder through the clearance space or throat between the upper end of the cylinder and the outer or peripheral portion of the dial. This throat constitutes a critical element of the knitting machine, as hereinafter set forth.

A principal object of the present invention is to provide a dial for this type of machine which by reason of its novel structural form may be mounted so that the working tips of the transfer bits are in relatively close proximity to the upper end of the needle cylinder and to the cylinder needles in the normal loop forming position.

Another object of the invention is to provide a novel dial structure which will afford a materially increased effective throat clearance with actual decrease of the distance of the transfer bits from the upper end of the needle cylinder.

Still another object of the invention is to provide a novel dial structure that will permit the use of transfer bits having a working tip formation less liable to interference with the dial needles, thereby affording relatively trouble-free operation of the machine at higher speeds.

A further object of the invention is to provide a machine of the stated type having ample throat clearance between the dial and the cylinder for accommodation of the looped fabric forming the turned welt, permitting frictiomfree passage of the loop to the interior of the needle cylinder.

A still further object of the invention is to provide a novel dial structure having means for effectively sealing the joint between the relatively movable upper and lower elements of the dial against inadvertent snagging of yarn in the joint as experienced with dials of the prior construction, as hereinafter more fully set forth.

The invention resides also in certain novel structural details hereinafter described and illustrated in the attached drawings wherein:

Fig. 1 is a fragmentary sectional view showing a dial made in accordance with my invention and showing also the relation of the dial to the needle cylinder and the elements of the sinker system;

Fig. 2 is a top plan view of the lower part of the dial in which the bits are mounted;

Fig. 3 is a sectional view on the line 3--3, Fig. 2;

Fig. 4 is a fragmentary view in perspective illustrating the manner in which the transfer bits are supported in the dial;

Fig. 5 is a similar fragmentary perspective view from the underside of the dial; i

Fig. 6 is a fragmentary sectional view illustrating conventional dial construction, and

Fig. 7 is a fragmentary view in perspective corresponding to Fig. 4 and showing the conventional dial illustrated in Fig. 6.

With reference to the drawings, a machine of the character to which the applicants invention relates comprises the usual needle cylinder 1 and a dial 2 for the transfer bits, said dial being mounted as shown adjacent the upper end of the cylinder with the peripheral portion of the dial overlying the cylinder. The machine also comprises the usual sinker ring 3 which embraces the upper end of the needle cylinder. 1

The dial 2 comprises two primary parts, namely, a lower member 4, which as shown in Fig. 2 is provided in its upper surface with a circumferential series of radial slots 5 for reception of the transfer bits 6; and an upper relatively movable cap member 7 which has a cam groove 8 at the underside which receives the actuating butts 9 of the bits 6. Relative rotation of the members 4 and 7 of the dial structure, which takes about the axis 11 of the needle cylinder, results in projection and retractive movements of the bits 6 in their respective grooves.

The bits 6 are of the type comprising an eye 12 at their forward ends which, when the bits are fully projected from the periphery of the dial, will occupy posi tions as shown in Fig. 1 wherein they are in vertical alignment with the needles 13 in the cylinder 1. When, as in the transfer operation, the needles 13 or certain of them are moved upwardly to a highposition as indicated in Fig. 1, the aligned needles will pass into the eyes. The forward walls of the eyes are split or divided vertically so, that when with the needles in the said high positions, the bits are withdrawn, the needles will escape from the eyes through the divided forward walls and will pick up the loops or bits of yarn from the hooked outer ends 15 of the bits. In this manner the loops are transferred from the bits to the needles. The general form of bits of this type and the manner in which they cooperate with the needles in the transfer operation is well known in the art.

As shown in Fig. 1, the fabric of the loop which forms the turned welt of a stocking produced on a machine of this character, started on the hooks 15 of the bits 6 in well known manner, passes inwardly as the knitting progresses over the top of the cylinder 1. The space 16 between the periphery of the dial and the upper end of the needle cylinder 1, herein designated as the throat, must be of sulficient width to afford free passage for the double layer of fabric which forms the welt. The throat clearance must provide space also for the sinkers 17 which operate in known manner with the needles 13 in the knitting operation. It is desirable, also, that the working tips of the transfer bits be as close as possible to the normal operating position of the cylinder needles, since the greater the distance between the transfer bits and the normal stitch-forming position of the needles 13, the greater will be the length of the loops in the initial courses laid in the hooks 15 of the transfer bits, and these undesirably extended loops will be carried into the base of the welt in the transfer operation. It is evident, however, that with the prior conventional dial construction shown in Figs. 6 and 7, the requirements of wide throat and needle and transfer bit proximity are not compatible, and that the greater the throat width, the greater must be the distance between the working tips of the transfer bits and the upper end of the needle cylinder and also between the tips and the position in which the needles operate in forming the stitches of the fabric.

There are other considerations which impose limitations on the form and location of the dial. It is essential,

Patented Mar. 12, .1957

for example, that the transfer bits have adequate support in the dial so as to permit their projection into operative positions with respect to the needles without deflections which might result in interference between the needles and the bits. To provide such support, it is desirable, that the radial extent of the dial be as great as possible, consistent of course with the diameter of the needle cylinder. It is desirable also that the eyes 12 of the bits be as large as possible so as to afford ample room for accommodation of the needles as they move upwardly into the eye and to avoid possible interference due to small deflection of the outer end of the bit from its normal plane and registered position with respect to the needle.

In accordance with my invention the peripheral portion of the lower member 4 of the dial 2 is undercut as indicated at 18, see particularly Figs. 1, 4 and 5. By reason of this undercut, the partition elements 19 which constitute the walls of and define the bit-retaining slots 5, or rather the upper portions of said partition elements which are designated by the reference numeral 19 in Figs. 4 and 5, are made to project outwardly radially beyond the body portion of the member 4, and the projecting portions 19 thus constitute the outer peripheral portion of the said member. Each of these projecting portions 19 has at its outer end an upwardly projecting boss 21 which, as shown in Fig. 1, extends into a circumferential recess or groove 22 in the underside of the cap member 7 of the'dial structure, and the function of which is described below. While, therefore, the slots 5 extend between the projecting portions 19 to the extreme peripheral edge of the dial member 4, the body part of this member is terminated inwardly of the periphery as indicated at 23. The lower edges of the bits 6, therefore, find support in the grooves 5 only to the edge 23, but the upper edges of the bits still find guide and lateral support between the projecting portions 19 of the groove partitions. The result of this construction is to very materially increase the effective width of the throat 16 over the throat Width afforded by the conventional dial structure illustrated in Figs. 6 and 7 wherein the lower member 24, corresponding to the member 4 of the dial structure shown in Fig. 1, extends radially substantially to the extreme outer peripheral edge of the dial structure as a whole. The advantage in throat clearance thus obtained will be apparent from a comparison of Fig. 1 of the drawings with the prior art showings of Figs. 6 and 7. It will be apparent also that with my novel construction the tips of the transfer bits 6 may be brought materially closer to the needles 13 in their normal working position, without sacrifice in effective throat width. The available increased throat clearance has several desirable effects. As described, it permils the dial to be moved downwardly toward the top of the needle cylinder without undue throat restriction to an extent bringing the working tips of the transfer bits 6 materally closer to the normal knitting position of the needles than had previously been possible. This improves the knitted product in a material respect in that it reduces the sizes of the loops at the base of the welt where the free edge of the loop is joined to the body fabric of the stocking, and makes a stocking which is not only improved in appearance, but which has better strength characteristics. It also permits a substantial increase in the size of the eye 12 so as to afford additional desirable clearance between the needles and the walls of the eye when the needles are elevated to initiate the transfer operation. It affords also additional clearance for accommodation of the fabric in the throat. By use of transfer bits constructed in accordance with the invention disclosed in my co-pending application for U. S. patent, Serial No. 495,262, now Patent No. 2,730,880, the gain in throat clearance is obtained without sacrifice of transfer bit stability, this by reason in part of the fact that the transfer bit, as formed in accordance with the aforesaid invention, has sufiicient inherent vertical and lateral rigidity to preclude any material deflection from its normal plane even when fully projected. It will be noted also that even in the fully projected position, the needle finds full lateral support in the dial substantially to the outer peripheral edge of the latter between the projecting portions 19 of the partitions which define the slots in which the bits operate.

A further material improvement is realized in the provision of the boss 21 on the outer ends of the said partitions which occupy the peripheral slot 22 in the cap 7 of the dial as previously described. Considerable difficulty has been experienced in the past due to a tendency of the yarn, particularly when initially laid onto the ends of the bits, to snag between the cap and bottom portions of the dial within the open slot indicated in Fig. 6 by the reference numeral 25. The interengaged bosses and slot 2122 provide in effect a labyrinth seal which prevents the entrance of the yarn into the space between the upper and lower relatively movable parts of the dial structure, and thereby creates a material reduction in lost production time by avoiding the shut-down periods resulting from the prior defect.

I claim:

1. For knitting machines of the type described, a dial for transfer bits comprising relatively movable contiguous upper and lower members, the said lower member having a body portion of materially lesser radial extent than the upper member and containing in the upper face thereof radial slots for reception of the said bits, and upper portions only of the Walls of said slots being extended beyond the peripheral edge of the body portion to afford correspondingly extended lateral bit-supporting surfaces.

2. For knitting machines of the type comprising cylinder and dial elements and cooperative knitting instrumentalities in said cylinder and dial, a dial structure including upper and lower members relatively movable about a central axis normal to the respective upper and lower confronting faces of the members, the said lower member having a body portion of materially lesser radial extent than the upper member and containing in the upper face thereof radial slots for reception of said instrumentalities, and upper portions only of the walls of said slots being extended beyond the peripheral edge of said .body portion to afford correspondingly extended lateral support for said instrumentalities.

3. In a knitting machine of the type comprising cylinder and dial elements and cooperative knitting instrumentalities mounted in said cylinder and dial, a dial structure in proximity to the upper end of the cylinder and including upper and lower members relatively movable about the axis of said cylinder, the peripheral p0.- tion of said lower member being in spaced overlying relation to the cylinder and said lower member containing in the upper face thereof radial slots for reception of said instrumentalities, and said lower member being recessed at the underside and inwardly from the periphery thereof to a point at the inner side of the cylinder and upwardly from said underside to an extent intersecting the lower portions of the slots so as to reduce the effective depth of the said peripheral portion and to thereby permit mounting of the dial with the peripheral portion thereof in relatively close proximity to the top of the cylinder without decrease in the effective width of the throat between the upper end of the cylinder and the dial structure.

References Cited in the file of this patent UNITED STATES PATENTS 625,856 Sturgess May 30, 1899 1,282,958 Scott Oct. 29, 1918 1,863,720 Lawson et a1. June 21, 1 932

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