US2503838A - Circular knitting machine - Google Patents

Description

A ril 11, 1950 F. R. PAGE CIRCULAR KNITTING MACHINE Filed Oct. 3, 1946 INVENTOR FRANK R. PAGE 5; his flier-keys a stitch cam which point or apex 5 and which Patented Apr; 11, 1 9 5 0 -Fran-k Raga. Laconia, N.

1i; Williams,

H-., assignor-= to Scott ncorporatedQlLaconia, N .-/H.,-a."c0r- .poration ofMassachusetts Application October 3, 1946, Seria1'No."-70'0,993 7-Claims. (Cl..66..57)

This inventionrelates to :istitc'h cams for circular knittingmachin'es using latchr'needles. It is-ianiobject of thiszinventiontozprovide a needlenper'ating orstitch cam of improved construcof the needle'l'atches with respect to the hooks will be'prevented. Another object is to provide will; prevent cutting of the yarn by the latch of the needles.

In the drawings:

Fig. 1 is a-iview .in elevation. of a stitch cam :for a circular knitting machine in accordance with this invention, the @cam beingshown as it would appear viewed from outside the needle circle;

Fig. 2 is a diagrammatic View showin the relation of the cam and needles in the operation of the needles as they would appear from the outside of the needle 7 circle, only each third needle being shown; and g Fig. 3 is detail views of the needle hooks showing their relation to the latch pivot line and the though the 'inventionisiequaliyapplicable to knitting machines having rotating cam rings and fixed needle cylinders. As shown, the cam comprises a triangularpieceofmetal havin a suitable curved face adjacent "the needle cylinder,

a central opening 2 to receive the bolt by which cooperates with another cam (not shown) in guiding the raising of the needles. The face 3 of the cam I is hollowfac spaced from the 3 comprises an upper straight portion 3a, a curved portion 3b and a lower straight portion 3c. The lower straight portion is offset or set back to the right from what its position would be if the curved not interposed between the straight portions 3a and 3c. The castin ofi level of the machine is indicated by the dotted line k, i positioned so that the loop being cast cit is caughttbyithe Ineedlefhook and retained by'the needle. The needle therefore knits a. tuck stitch. v

To overcome thisobjection, the cam is hollow;-

ground on the draw-down side, leaving 'a straight therefore is gradually accelerated: to the speed given by the portion 30.

Forming the curved taken with the straight portion 3a offsets the the yarn as it the stitch just knit.

. straight portions feeding means, independent by the latch against the rivet cheeks and the yarn cut as the latch is closed. This is particularly important where plating yarns are being fed to the needles.

It will be seen that the new cam face not only has a hollow part to give the advantage of a slower closing of the needle latch but has a straight lower part to cast off the stitch which therefore-has all the advantages of a plain cam face, i. e. is not hollow ground. This lower portion gives the needles a uniform rate of movement. The parts of the cam face are so united that the cam engages the yarns at a higher point on the needle when'the latch is closing, thereby avoiding cutting of the yarns and yet the speed of closing of the latches and the speed of cast off are independent of each other.

What I claim is:

1. In a circular knitting machine having independent latch needles, a stitch cam having a needle draw-down surface comprising spaced upper and lower straight portions and an intermediate curved portion merging into said lower straight portion, said curved portion operating said needles during the time the latches are closing beginning about the time the latches start to close, said lower straight portion lowering said needles at a greater speed than said upper straight portion, and said curved portion lowering the needles only at a speed less than that of said upper straight portion.

2. In a circular knitting machine having independent latch needles, a stitch cam having a needle draw-down surface consisting upper straight portion for drawing the needles of an down at a, predetermined rate, a curved portion for drawing each needle down at a slower rate until the needle latch is closed and a lower straight portion for drawing the needles down at a uniform rate greater than said predetermined rate for casting off the previously drawn ,loops.

3. In a circular knitting machine having independent latch needles, a stitch cam having a needle draw-down surface comprising spaced connected by an intermediate curved portion, the curved portion being. so

shaped and located as to provide a lowering of .the needles begimiing substantially with the closing of the latches which is slower than the lowering of the needles on the straight portions.

, 4. In a circular knitting machine having independent latch needles, the combination of yarn latch needles whose latches cast off the stitches, and a stitch cam having a needle draw-down surface comprising spaced straight portions connected by an intermediate curved portion so shaped and located with relation to the needle latches as to provide a lowering of the needles during the closing of the latches that is slower than the lowering on the straight portions.

stantially with and during the time the latches are closing, said lower straight portion being adapted to lower said needles at a greater speed than said upper straight portion, and said curved portion being adapted to lower the needles at a speed less than that of said upper straight portion.

6. In a circular knitting machine having independent latch needles, the combination of yarn feeding means, independent latch needles whose latches cast off the stitches, and a stitch cam having a needle draw-down surface consisting of an upper straight portion for drawing the needles down at a predetermined rate, a curved portion beginning at a point corresponding with the time when the needle latches begin to closeand so curved and located with respect to the needle latches as to draw each needle down at a slower rate while the needle latch is closing, and a lower straight portion adapted to draw the needles down at a uniform rate greater than said predetermined rate for casting off the previously drawn loops.

7. In a circular knitting machine having independent latch needles, a stitch cam having a needle draw-down surface comprising spaced upper and lower straight portions and an intermediate curved portion, the curved portion being so curved and located with respect to the needles that it begins to lower them at a lesser rate about the time the latches begin to close, the lower straight portions being so located as to lower the needles at a greater rate than said upper straight portion.

FRANK R. PAGE.

REFERENCES CITED UNITED STATES PATENTS Number Name Date Re. 20,423 Robaczynski June 22, 193'? 1,105,735 Wildman et al Aug. 4, 1914 1,149,884 Ames Aug. 10, 1915 1,183,604 Swinglehurst May 16, 1916 1,982,566 Belford Nov. 27, 1934 FOREIGN PATENTS Number Country Date 368,376 Great Britain Mar. 4, 1932

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