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Publication numberUS3230742 A
Publication typeGrant
Publication dateJan 25, 1966
Filing dateApr 3, 1964
Priority dateApr 3, 1964
Publication numberUS 3230742 A, US 3230742A, US-A-3230742, US3230742 A, US3230742A
InventorsAlbert W Roedel
Original AssigneeTextile Machine Works
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Sinker mechanism for knitting machines
US 3230742 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Jan. 25, 1966 A. w. ROEDEL 3,230,742

SINKER MECHANISM FOR KNITTING MACHINES Filed April 5, 1964 TlE- l Z6 Z3 22 35 36 20 3. I5 25 /6 INVENTOR A/beri l V Paeoe/ ATTORNEY.

United States Patent 3,230,742 SINKER MEGHANISM FGR- KNITTING MACHINES Albert Roedel, North Asheboro, N;C., assignor to;

This invention relates, to circular knitting machines and more particularly to the sinker mechanism of such machines.

In circular knitting machines the sinkers are mounted in radially extendingslots for movement, in cooperation with stitch drawing movements of the needles, in inner and. outer sinker rings which are secured to the needle cylinder of the machine for rotation therewith. Conventional ly, the sinkers are constructed ofhardjened steel and the inner sinker ring, which both guides and supports the inner ends of the sinkers over which yarn stitches are drawn by the needles, is also constructed of steel; The inner sinker ring i's also provided'with. an outer peripheral surface which is adapted to slidably support the upper ends of the needles during their stitch drawing movements.

During normal operation of the machine the needles are lowered from, a high yarn taking level to measure or draw yarn for new stitches over the platforms or knockover surfaces of the sinkers and to knock off the previously formed stitches from the needles. As the needles reach their lowest stitch drawing position and while the newly drawn stitches continue to exert a slight downward pressure on the platforms of the sinkers, the sinkers are advanced inwardly to tension the, previously formed stitches to the backs of the. needles and; to hold the new stitches, as the needles are raised to. clear the new stitches prior to the next yarn taking and. stitch1 drawing operation of the needles, Wln'leboth the needles and sinkers cause gradual wear in the surfaces of the inner sinker ring engaged thereby, the wear in the bottoms of the sinker slots is the most critical since it, changes the, vertical relation between the platforms of thesinkers and. the needles as the needles drawn yarn for the new stitches. When this wear in the bottoms of the sinker slots reachesv a point that it affects the lengths of the stitches and causes the formation of defective fabric, the inner sinker ring must be discarded and replaced by a new ring.

Heretofore, in order to avoid the frequent discarding of worn parts, it has been proposed to recondition the inner sinker ring by removing a portion of the material of the ring beneath the slots and replacing the removed material by a hardened steel insert. While this insert acted to restore the bottom surfaces of the sinker slots to their normal condition wear Occurring on other portions of the inner sinker ring engaged by the sinkers and needles eventually necessitated replacement of the inner sinker ring.

It is an object of the invention to provide the inner sinker ring of a circular knitting machine with a replaceable insert to renew Worn portions of the sinker ring which will eliminate the above noted and other objections to prior proposals.

Another object of the invention is to replace the worn portions of the inner sinker ring of the sinker mechanism of a circular knitting machine with an insert of synthetic material such as nylon or the like which has a greater resistance to wear than the original metallic material of the inner sinker ring.

A further object of the invention is to provide a metallic inner sinker ring with a replaceable insert portion of synthetic material, the insert portion having slots for guiding the sinkers and a bearing surface for supporting the needles during operation thereof.

With these and other objects in View, which will become apparent from the following detailed description. of

the illustrative and practical embodiment of the invention shownin the accompanying drawings, the invention comprises the novel elements and features of construction, as more particularly pointed out in the claims.

In the drawings:

FIG. 1 is a. cross-sectional view through the knitting head of a conventional circular knitting machine having a replaceable insert incorporated in the inner sinker ring; of the knitting head according to the instant invention; and

FIG. 2 is a top plan view on a reduced scaleof the inner sinker ring.

Referring to FIG. 1 of the drawing, there is, shown a portion of the knitting head of a circular knitting machine including a needle cylinder 19 having slots 11 for pivotedlatch needles 12 which are raised and lowered in the slots through knitting movements. in cooperation with sinkers 15' to. form yarns into stitches of tubular fabrics such as stockings and the like, in a conventional manner. The sinkers are guided for sliding movements between the; needles in radially extending slots 16 formed in an outer sinker ring 17 secured to the outer surface of the needle cylinder It at the upper end thereof and in aligned; slots 20 formed in an inner sinker ring 21 secured in adjusted position to an inner surface of the needle cylinder. The inner sinker ring 21 is provided with an outer peripheral bearing surface 22 for slidably supporting the needles 12 during knitting movements of the needles. The sinkers 15 are provided with butts 23 for engagement in a cam groove 25 in a sinker cap 26, the cam groove acting on the butts 23 to advance and retract the sinkers in timed relation to the operation of the needles. The sinker cap 2e has a depending flange 27 having an inner bearing surface 3d closely interfitting an outer bearing surface 31 on the outer sinker ring 17 to maintain the sinker cap in accurately centered relation to the outer sinker ring.

During operation of the machine to form yarn into stitches, with the sinkers in retracted position as determined by the cam groove 25, the needles are raised to clear previously formed stitches thereon and after taking the yarn are then lowered to measure or draw the yarn for new stitches over platforms or knockover surfaces 32 of the sinkers, and to knock over the previously formed stitches. The sinkers are then advanced inwardly to tension the previously formed stitches to the backs of the needles and to hold the new stitches before the needles are again raised to clear the new stitches. During their cooperating stitch forming movements, the needles 12 and sinkers 15, which are made of hardened steel, gradually wear the surfaces of the inner sinker ring, which is also made of steel, engaged by the needles and sinkers. When this wear reaches a point that it affects the length of the stitches and causes defective fabric, the inner ring must be discarded and replaced by a new ring.

In order to greatly increase the wearing life of the inner sinker ring 21 and to avoid discarding the entire ring when excessively worn according to the instant invention, the upper end of the ring is machined to remove the slotted portion and the outer diameter of the ring is turned down to form an upper flange 34 as indicated in FIG. 1, and replaced by a replaceable insert 35. The insert is in the form of a ring (FIG. 2) which is initially machined only to form a recess to interfit the reshaped upper flange 34 of the ring 21 and the insert is then bonded to the upper and outer peripheral surfaces of the flange of the ring by a layer 36 of adhesive. The insert is then machined to the same shape as the original ring and reslotted to receive the sinkers.

Preferably the insert 35 is made of a material such as a synthetic linear condensation polymer of the type generally referred to as nylon or any other synthetic material having similar characteristics. The nylon provides an ideal bearing material for both the metallic needles and sinkers that resist wear and greatly increases the life of the remaining metallic portion of the inner sinker ring.

The adhesive employed for the layer 36 is of a type that is thermo setting and that will adhere or bond itself to both the metallic material of the inner sinker ring 21 and the nylon material of the insert. In carrying out the instant invention the adhesive layer that was found to provide the most desirable results includes two well known commercial adhesives, Cycle-weld which is a compound of phenol-formaldehyde and a synthetic rubber such as Buna N made by Chrysler Corp. and Cascophene No. RS216 which is a resorcinal-phenol compound made by the Borden Co.

In preparing the parts for jointure the interfitting surfaces of the insert 35 and inner sinker ring 21 are slightly roughened and thoroughly cleaned of all dirt and other foreign matter. The metal surfaces of inner sinker ring are coated with the Cycle-weld compound which is permitted to air dry for at least fifteen minutes. A second coating of the Cycle-weld is then applied to the first coating and permitted to air dry for approximately fifteen minutes after which it is baked for fifteen minutes at 170 and for thirty minutes at 340 to remove all of the solvent. A coating of Cascophene is then applied over the coating of Cycle-weld and the surfaces of the insert and the latter coatings are allowed to air dry for a few minutes after which the insert 35 is assembled and clamped to the inner sinker ring 21. The parts are permitted to cure for approximately forty-eight hours to completely set the cement and permit the cement to reach its maximum bonding strength. The insert is then machined to the required shape and slotted as above set forth.

The instant invention is applicable to both new and reconditioned inner sinker rings and results in a longer operating life of the ring. Furthermore, the insert itself when becoming worn may be readily replaced which permits the continued use of the metallic portion of the inner sinker ring.

Having described the invention in detail it will be .understood that these details need not be strictly adhered to and that various changes and modifications may be made falling within the scope of the invention as defined in the following claims.

What is claimed is:

1. In a circular knitting machine having a rotatable needle cylinder, slots in said cylinder, needles movable through stitch drawing movements in said slots, sinkers cooperating with said needles, an outer sinker ring secured to said cylinder, an inner sinker ring secured to said cylinder and having an outer peripheral surface for supporting said needles during said stitch drawing move-. ments thereof, radially extending slots for said sinkers in said outer and inner sinker rings, said inner sinker ring having a nonmetallic portion of synthetic linear condensation polymer in which said slots for said sinkers and said outer peripheral supporting surface for said needles are formed, and a metallic portion which is secured to said cylinder, said metallic portion of said inner sinker ring having an upper flange and said non-metallic portion of said inner sinker ring having a recess therein to receive said upper flange of said metallic portion.

2. An inner sinker ring for a circular knitting machine having a non-metallic portion of synthetic linear condensation polymer and a metallic portion, slotsin said nonmetallic portion for supporting sinkers for radially sliding movements thereof, a vertical extending peripheral surface on said non-metallic portion for supporting needles during stitch drawing movements thereof, a recess in 'said non-metallic portion, an upper flange on said metallic portion of said sinker ring adapted to be received in said recess on said non-metallic portion, and a layer of adhesive between the upper and outer peripheral surfaces of said upper flange and the surfaces of said. recess to bond said non-metallic portion to said metallic portion.

References Cited by the Examiner UNITED STATES PATENTS 2,271,852 2/1942v Brumbach 66110 2,384,451 9/1945 Brumbach 66110 2,710,528 6/1955 Cobert 66-110 2,931,198 4/1960 Bitzer 66-410 2,951,355 9/1960 Bryant 66-110 FOREIGN PATENTS 819,686 9/1959 GreatBritain.

825,637 12/1959 GreatBritain.

861,066 2/1961 Great Britain.

RUSSELL C. MADER, Primary Examiner.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2271852 *Jun 16, 1938Feb 3, 1942Textile Machine WorksBearing construction for knitting machines
US2384451 *Oct 7, 1941Sep 11, 1945Textile Machine WorksSinker head for knitting machines
US2710528 *Nov 22, 1950Jun 14, 1955Beautiful Bryans IncVerge plate
US2931198 *Oct 19, 1956Apr 5, 1960Textile Machine WorksSinker-head structure for knitting machines
US2951355 *Dec 12, 1958Sep 6, 1960Bryant Marvin RCircular knitting machine
GB819686A * Title not available
GB825637A * Title not available
GB861066A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3545233 *Jun 19, 1967Dec 8, 1970Lombardi Victor JCylinder and dial construction for knitting machines
US3754416 *Jul 7, 1971Aug 28, 1973H ApprichApparatus for the production of knit goods
US5577401 *Nov 15, 1995Nov 26, 1996Monarch Knitting Machinery Corp.Knitting machine cylinder having a hardened top insert ring and method of making same
US5609044 *Jan 19, 1996Mar 11, 1997Monarch Knitting Machinery Corp.Durable knitting machine cylinder assembly and method of making same
US6176107 *May 27, 1999Jan 23, 2001Monarch Knitting Machinery Corp.Circular knitting machine with replaceable member for restricting vertical movement of sinkers
EP1057914A2 *May 10, 2000Dec 6, 2000Monarch Knitting Machinery CorporationCircular knitting machine with replacable member for restricting vertical movement of sinkers
U.S. Classification66/8, 66/107
International ClassificationD04B15/06
Cooperative ClassificationD04B15/06, D04B15/14
European ClassificationD04B15/06, D04B15/14