US3516268A

US3516268A - Device for minimizing twisting of circular knit fabric

Info

Publication number: US3516268A
Application number: US759299A
Authority: US
Inventors: Caley A Foreman
Original assignee: US Industries Inc
Current assignee: DANSKIN Inc; Danpen Inc; US Industries Inc; Security Pacific Business Credit Inc
Priority date: 1968-09-12
Filing date: 1968-09-12
Publication date: 1970-06-23
Anticipated expiration: 1987-06-23

Description

June 23, 1970 c. A. FOREMAN 3,516,268

DEVICE FOR MINIMIZING TWISTING OF CIRCULAR KNIT FABRIC Filed Sept. 12, 19,68

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INVENTOR 27 27 CALEY A FOREMAN l I v ATTORNEYS United States Patent 3,516,268 DEVICE FOR MINIMIZING TWISTING 0F CIRCULAR KNIT FABRIC Caley A. Foreman, Grenada, Miss., assignor to US. In-

dustries, Inc., New York, N.Y., a corporation of Delaware Filed Sept. 12, 1968, Ser. No. 759,299 Int. Cl. D04b /88 U.S. Cl. 66-149 6 Claims ABSTRACT OF THE DISCLOSURE A device for minimizing the twisting of fabric produced on circular knitting machines, which device is particularly useful when the fabric is of considerable length as for example waist length stockings or panty hose, especially those of stretch yarn which are loosely knitted in order to permit later development of crimp or stretch characteristics.

In a circular knitting machine the fabric is taken off within the needle cylinder by means of a take-off device which may be of any one of a number of types, but which is intended to permit rotation of the fabric with the needle cylinder at all times.

Recently ladies stockings have been knitted in much greater lengths than heretofore due to the fact that panty hose comprising two stockings of waist length has become popular and due also to the fact that yarns have been developed which require loose knitting and subsequent crimp development, resulting in the knitted fabric being much longer than present takeup devices can care for, and likewise resulting in twisting of the fabric, particularly when the take-up carriage drops to its lower limit and is no longer held up by the fabric, or in the case of a vacuum take-up, when the fabric accumulates in the vacuum tube. In addition, there is likely to be some twisting resulting through air or fabric tube friction and even on machines not equipped with take-up facilities, the fabric has a tendency'to twist due to air or fabric tube friction or to reaching the floor beneath a machine.

Although attempts have been made to solve the problem of twisting by elevating the machine to provide more floor-to-knitting head length, or by installing greaterdiameter fabric tubes to permit the fabric to balloon out to foreshorten the fabric, these attempts have met with very limited success, since the fabric tube or air friction, or both, still tends to cause the fabric to lag behind the cylinder rotation.

There are a number of disadvantages of this twisting, amongst Which is the fact that when knitting yarns which are subsequently crimped-developed, the fabric must be straightened before it can be steamed to develop the crimp, since if it is not, the crimp will be unevenly de veloped and shaded areas will result. This prevents the blowing of the stockings into a bag for subsequent steam setting and requires that the twisted fabric be untwisted and laid out flat, which is time-consuming and hence expensive. Additionally, when low-denier fabric in the range of from 15 to 45 denier is twisted, the loops tend to lock together and cause pulled threads when the fabric is untwisted. Furthermore, tension of the pull-off is uneven, resulting in differential stitches and stitch distortion.

My invention is simple and inexpensive while at the same time providing a positive means for substantially preventing fabric twist. My invention consists essentially of a tube or rod extending downwardly centrally of the needle cylinder and driven synchronously with that cylinder to provide a rotating core about which the fabric 3,516,268 Patented June 23, 1970 accumulates as it is knit. The fabric adheres to this core and therefore continues at all times to rotate with the needle cylinder so that no twisting of the fabric occurs. Any tendency of the fabric to twist, as a matter of fact, merely causes it to adhere to the core and to thus even more positively rotate with the core and prevent other than a very slight initial twisting.

It is a primary object of the invention, therefore, to provide a device for use with a circular knitting machine which prevents or minimizes the twisting of fabric and thus minimizes the defects resulting from the knitting of long fabric lengths, while at the same time requiring no extensive changes in the knitting machine and thus being relatively inexpensive to manufacture and install.

Other objects and features of the invention will become apparent when the following description is considered in connection with the annexed drawings, in which:

FIG. 1 is a schematic fragmentary vertical crosssectional view of a conventional circular knitting machine, modified in accordance with my invention. The machine so modified is of the type normally having a mechanical take-off, and

FIG. 2 is a view similar to FIG. 1, but showing my invention applied to a circulating knitting machine having a vacuum take-off.

Referring now to the drawings and particularly to FIG. 1, there is shown therein a conventional circular knitting machine generally designated 10, having a needle cylinder 11 carrying the needles 12 and carrying likewise the usual sinker ring 13 and sinkers 14. In addition, as is customary, the machine includes a transfer dial jack 15 carrying transfer jacks (not shown) and the needle cylinder 11 and transfer dial 15 are driven in synchronism through the medium of gearing including the bevel gear 16 and the bevel gear 18.

In the usual manner, a fabric tube 20 is fixed by any suitable means within the needle cylinder 11 and fixed supporting cylinder 21. The fabric, as it is produced by the needles 14, falls into this tube 20. In the type of machine having a mechanical take-off arrangement, it is customary to supply a cup 22, which in a manner not shown in FIG. 1, can be elevated to an upper position and operated in such a manner as to grab the end of the fabric after a short length has been produced and lowered at the rate of fabric production until it reaches a lower position, where it remains until the knitting is completed, after which it is moved to a still lower position and the fabric blown out, by means of an air jet 30 into a receptacle cup 32. The cup 22 is mounted in any suitable manner to cause these motions and is freely rotatable on a vertical axis so that the fabric can cause rotation of the cup. As has been stated above, when the stocking is of great length, the mechanical take-up device does not function well, in part because the cup 22 when in its intermediate position is not driven by the fabric and the fabric balloons out and engages the tube 20 or the cylinder 21, or as a result of air friction, becomes twisted.

By my invention I support a rod or tube 23 from the dial 15, thus providing a rotating core about which the fabric is deposited as it is knit. Preferably the rod 23 is fixed to the dial 15 by means of a spring 24 so that the dial may be tilted to provide for normal maintenance, although other types of flexible connection may be utilized, and the rod may be driven in other manner synchronously with the needle cylinder.

The customary grab type take-up is modified so that it consists of a disc or platform 25 mounted on the cup 22, with no provision for elevating the cup to an upper limit and with no provision for grabbing the fabric while the cup is in that upper position. On the contrary, the

cup 22 terminates in the disc 25 which is fixed thereto, the cup 22 rotating as usual on antifriction bearings while supported on the piston rod of a pneumatic cylinder 27. It will be understood of course that in place of the pneumatic cylinder 27 a mechanically operated device which is in common use may be substituted and operated by cams driven by the drive mechanism of the knitting machine in a customary manner.

The disc 25 is provided centrally thereof with a depression 28 and is cupped as indicated. The lower end of the core rod or tube 23 is conical or rounded and mates with the depression 28 so that the core drives the cup 22 and disc 25. It should be noted at this time that the core rod or tube 23 is highly polished throughout, as is the surface of disc 25, in order to prevent snags in the fabric.

As has been indicated, the usual pulley and weight mechanism for causing the grab mechanism to be elevated to a position just under the inner tube 20 is omitted when my improved take-off device is utilized, since it no longer would serve any function, due to the extreme length of the stockings intended to be knitted, as mentioned above. As is usual in an arrangement of this sort, when the stocking has been finished and pressed off, the control mechanism of the knitting machine admits air under pressure to the cylinder 27 and simultaneously to a jet 30. The jet 30 is situated diametrically across the outer tube 21 from a discharge tube 31. Thus, when the disc 25 is lowered, the jet causes the stocking to pass into the tube 31 and to be driven upwardly and be deposited in the receptacle 32, from which it may be manually taken or, in some instances, discharged through a pneumatic system to a central point.

Referring now to FIG. 2, it should be noted that the same reference characters have been utilized in designating similar parts in the application of my invention to the common vacuum type take-off mechanism. As shown in FIG. 2, the tube or rod 23 is made in two parts, one of a lesser diameter than the other, as illustrated at 23a and 23b, in order to accommodate the device to the inner tube 20 which normally has a lesser diameter than the corresponding fabric tube of a machine having mechanical grab type take-off. The device is otherwise the same and operates in the same manner to assure that there will be no rotation of any portion of the knitted fabric tube relative to the needle cylinder and transfer jack dial.

In this instance the take-off mechanism comprises a lower inner perforated cylinder 40 together with an outer supporting cylinder 41, the inner cylinder having an opening 42 which permits egress of the tubular fabric when the piston rod 26 is lowered. Joined to the outer cylinder 41 is a tube 43, which at its upper end extends into a housing 44 and is perforated, as indicated at 45, within that housing.

During knitting, vacuum is applied to a tube 46 and therefore to the housing 44, perforations 45, tube 43, and through perforations of the inner tube 40 to that inner tube and thus causes the stocking to be drawn downwardly through the fabric tube 20 and to accumulate upon the disc 25. Tube 43 is closed at its upper end by a pivoted top 47, and the housing 44 has an extended portion 48 which terminates in a tube 49 having a U-bend enabling it to discharge into a receiving basket 50. Also, at the lower bend of the tube 43 there is provided an air jet 51 which is similar to the air jet 30 described in connection with the FIG. 1 application. When a stocking has been completed the control mechanism of the knit ting machine causes the cylinder 27 to actuate and pull down the piston rod 26, thus freeing the lower end of the fabric, and at the same time a jet of air is emitted through the jet 51, which causes the stocking to be expelled into tube 48 through the top 47, tube 46 then being closed by a valve 52 also operated by the knitting machine control mechanism and the pivoted cover 47 being open. As a result, the stocking is propelled through the tube 49 and is received in the basket 50.

As mentioned hereinabove in connection with the application of my invention to the mechanical grab type take-off, a pneumatic conveyor system may be connected to the individual receiving baskets 50 so that stockings may accumulate and be taken from the machines of a group under a specialized control. However, this forms no part of the present invention, which is limited entirely to the provision of means for assuring that stockings will not be so twisted during the knitting and take-off thereof as to prevent proper crimp development and other detrimental effects.

Also as has been indicated the preferred mode of operation is to drive the rod 23 from the needle dial and by friction drive the disc or platform from the rod. However, it is entirely possible to mount the rod 23 on the needle dial for freer rotation with respect thereto and to drive the disc 25 either through connection to the piston rod 26 or otherwise synchronously with the needle cylinder.

1 While I have described a preferred form of my invention and have shown it as applied to slightly different forms of circular knitting machines in common use, it is to be understood that many variations would be possible and I therefore wish to be limited not by the foregoing description, but on the contrary, solely by the claims granted to me.

- What is claimed is:

' 1. A device for preventing twisting of fabric as it is knitted by a circular knitting machine having a rotating needle cylinder and a synchronously rotating concentric dial and in which the fabric accumulates within the said disc for limited vertical movement relative to said dial and rod, means normally urging said disc upwardly against said rod and means for driving said rod and disc synchronously with the needle cylinder.

2. A device as claimed in claim '1 wherein said rod is fixed to said dial and wherein said disc is mounted for free rotation about a vertical axis in alignment with the axis of said dial.

3. A device as claimed in claim 1 wherein means are provided to move said disc downwardly away from said rod upon completion of a predetermined fabric length.

45A device as claimed in claim 1 wherein said rod hasa curved lower end and said disc has a mating depression centrally of the upper surface.

5. A device as claimed in claim 1 wherein said rod and said disc are highly polished.

- 6. A device as claimed in claim 1 wherein said rod is connected to the dial by means of afiexible connection whereby said dial may be tipped to permit inspection.

References Cited UNITED STATES PATENTS 3,071,948 1/1963 Comas 66-149 3,214,944 11/1965 Kienez 66-149 RONALD FELDBAUM, Primary Examiner