US1718648A - Circular-knitting machine - Google Patents

Description

June 25, 1929. F. ISRAELSON CIRCULAR KN ITTING MACHINE Filed Nov! 14, 1927 Patented June 25, 1929.

UNITED STATES FRITZ ISRAELSON, OF STOCKHOLM, SWEDEN.

CIRCULAR-KNITTING MACHINE.

Application filed November 14, 1927, Serial No. 233,116, and in Sweden September 1'7, 1926.

This invention relates to circular knitting machines of the type having an annular needle cylinder and a cam cylinder rotatable with respect to each other and in which said cam cylinder carries a ledge to support the needle butts which are guided in vertical grooves in said needle cylinder, and cams to reciprocate the needles in the stitch forming operation.

The object of this invention is to enable the use of such niachiities for the manufacture of those kinds of knitted wares hitherto manufactured by such machines but also knitted wares having longitudinally extending. one-coloured or medley stripes, as well as of checkered. knitted wares or wares presenting combinations of such designs and plain knittin The invention is characterized. by the provision in. front of the stitch cams or each set of stitch cams, of a point-lever which under the influence of a spring or weight is normally held in engagement with the above mentioned ledge in order to guide the needle butts into an inoperative level outside the cam slot formed by the stitch cams, said pointlever being so shaped on its surface facing said ledge that each needle butt after shifting the point lever from said ledge is intro duced between the point of the lever and said ledge to allow to engage said cam slot and cause the lever, after a certain relative rotation of the needle cylinder and cam cylinder cm'rcsponding to a number of needle pitches, to turn on its pivot away from the ledge so as to allow a further needle butt to enter the space between the lever and the ledge. In this way a grouping of the needles into operative and inoperative needles once effected at a point-lever will automatically maintain itself during any desired part of the operation. of the machine.

The invention is illustrated in the accompanying drawings. Fig. 1 is a development of the inside of the cam cylinder 0 f a circular knitting machine according to this invention.

Fig. 2 is a development of the outside of said cam cylinder.

Fig. 3 is a development of part of the inside of the cam cylinder of a modified embodiment of a circular knitting machine according to the invention.

lVith reference to Figs. 1 and 2 the numeral 1 indicates the development of the cam cylinderwhich is rotatable in the direction of the arrow around the annular needle cylinder (not shown) with its vertical grooves to guide the needles. Only the butts of the needles are indicated in the drawing by short strokes in conventional manner. The cam cylinder is provided with an inwardly projecting ledge 2 forming a support for the needle butts. In the embodiment shown said ledge is interrupted at two points by a cam slot 7 to guide the needles in the stitch forming operation. In front of each cam slot a vertically adjustable raising block .3 is provided adapted to lift the needles to such a height as to release the needle latches from the loops previously formedwhich will now place themselves around the stem of the needles. Needles so positioned are shown at 4 to the right in Fig. 1. The needles lifted by a block 3 will embrace a yarn guided by a yarn-guide whereupon said needles are drawn down by the knitting cam 5 which is vertically adjustable to vary the length of the stitches. Thesecuring of the cam 5 in the desiredposition is effected by means of the screw 6, Fig. 2. As the earn 5 moves a needle downwards into the cam slot 7 the hook of the need 10 will carry the yarn engaged by it down through the loop embracing the stem of the needle. The respective co-operating cam sin-face will then lift the needle butt up on to the ledge to cause the loop to open the needle latch. In this position the needle will remain until it is again acted on by a cam slot. I

In the drawing the cam cylinder is shown as provided with two sets of stitch cams, that is, two cam slots whereby each needle will produce two stitches during each revolution of the cam cylinder. The cam cylinder is accordingly provided with two yarn guides which may either guide yarn of the same colour or yarns of different colours, and in the latter :ase striped knitting will be obtained with one row of each colour.. If desired, the cam cylinder may be provided with more than two sets of stitch cams, that is,

more than two slots, one yarn guide and one yarn reel being provided for each cam slot.

It is evident,jthat if a needle is lifted to such a position that it cannot be engaged by the cam 5 to be drawn downwards said needle will not. form any stitch. The yarn that should be engaged by said needle will then be placed on the rear side of the stitch formed at the corresponding point of the work by a succeeding cam slot.

The present invention has now for its object to provide means whereby an automatic raising of certain individual needles or groups of needles into an inoperative level will be effected. This is realized by the provision of movable point levers 8 disposed in front of the raising blocks 3. In the drawing the point levers 8 are shown as mounted on pivots 9. The levers 8 may be operated by springs or weights so as normally to hold the point 11 down against the ledge 2 or against an adjustable block 12 therein. The upper side 17 of the-lever, 8 forms in this position a cam shapedextension of the ledge to pick up the needle butts which in the rotation of the cam cylinder engage'the point of the lever causing thenr'to slide up on the lever to be thereby lifted to such an extent that they cannot be engaged by the cam 5. To again draw such ino erati've needles down into operative level a owering cam 10 is provided behind each cam 5 on the-inside of the cam cylinder. The levers-8 are formed on their side facing the ledge with 2. depending projection 14 which in the normal position of the lever, that is, when the point thereof bea-rsagainst the block 12,'wi1:l bear against the ledge 2. Between the'point 11 and said projectionl l the lower surface of the lever forms a concave curve 13.

Assuming a number of needles, say 3, are introduced between the righthand lever 8 and I the ledge Fig.1, 'and a-ssuming the left hand I earn slot shown in this figure to be removed.

Thedistancebetween thepoint 11 and the projection'lmay correspond to, say pitch of six needles After three needles have been introduced (below the lever '8, then three needles are moved upon the upper surface 17 of the lever. When a nee'dle, as 15, is just below the projection 14 with-its butt resting on the ledge 2, then the projection 14' bears upon the upper edge of said butt so as to hold the lever 8 I in raised position in which position there will lbe a'sulficient gap between the point 11 of the lever- 83nd the block 12 to permit a needle butt toentersaid gap. In the continued rotation of thecam cylinder "the lever 8 is maintained in said position until the projection 14 has passed the needle 16,-and during said move- :ment three further needle butts have been allowed to enter 'thespace below the lever 8 isj then 'allowed to return to its normal position in engagement with the block 12 thereby causing a number, in the case assumed three, needles to ride up on the upper surface 17 of the lever. As the length of the curved lower surface of the lever 8 corresponds to the pitch of six needles, the first one of the needles passing below the lever will reach the projection 14 when the said three needles have just slid up on the surface 17. Consequently, the lever will now be lifted by said three first-mentioned needles to again permit three other needles to enter the space below the lever 8. The lever will then again be restored to normal and maintained there until the succeeding three needles have slid up on to the surface 17 whereupon the operation described is repeated. Thus, the lever 8 will operate automatically alternately to pass three needles to the cam slot to form stitches and three needles outside said cam slot, said lastmentioned needles placing only a float thread on the inside of the knitted fabric the length of which float is equal to the width of 3 stitches. The sinking cam 10 situated beyond the cam slot 7 will lower said inoperative needles to again bring them into position for selection.

It will be seen from the above description that if initially five needles were passed below the lever 8 and one needle over the lever 8,then said five first-mentioned needles should be allowed to form stitches but not the sixth needle, and in such case five stitches would alternate with a float thread corresponding to the width of one stitch on the inside of the knitted fabric. If initially six needles are introduced below the lever 8 the lever will be continuously maintained in lifted position and the machine will in such case operate as if no lever 8 existed. It is evident that with a length of the curved lower surface of lever 8 corresponding to the pitch of six needles all combinations from six operative to five inoperative needles may be obtained. By the useof levers of another length of said curved surface any combination desired may be obtained.

According to the above specification the grouping of the needles into operative and inoperative groups as necessary for the production of pattern fabric, when once initially made, will automatically maintain itself under the control of the needles, inasmuch as each needle which passes the lever on its way to the cam slot will operate the lever to allow another needle to pass to the cam slot. In the preferred embodiment of said invention as described in the said specification those the needle supporting ledge upon which projection the needle butts will ride so as to lift the lever sufficiently to allow another needle to enter between the lever and the ledge. The distance between the point of the lever and said projection corresponds to the largest number of needles which is desired to keep out of operation at a time.

The said projection may be formed integral with the supporting ledge or be rigidly or adjustably attached thereto.

The structure shown in Fig. 3 (JOIIGSpOllClS substantially to that shown in Fig. 1 and the like reference numerals indicate similar parts in both views.

The difference with respect to Fig. 1 consists in this that the point lever 80 is formed without any projection (as 14) the under surface of the lever being plane except for the curve 130.

Instead of the said projection 14 an up wardly extending abutment 18- is provided in the supporting ledge 2. Said abutment which may be rigid or adjustable is directed with its point at the plane under surface of the lever 8 immediately beyond the end of the curve 13 and reaches with its point to such a height above the ledge 2 that the lever 8 will rest thereon with its plane under surface when the point 111 thereof rests on the block 12 so that a needle butt (as 15) when in contact with the point of the abutment 18 will lift the lever 8 to such an extent as to cause it to allow a further needle butt to pass through the gap between point 11 and block 12.

The operation is otherwise similar to that described in connection with Figs. 12.

What I claim is:

1. In a circular knitting machine, an annular needle cylinder to guide the needles and a cam cylinder, said cylinders being rotatable relatively to each other, a ledge on said cam cylinder to support the butts of the needles and a plurality of knitting positions on said cam cylinder, a shift-able lever in front of each of said knitting positions to form alternate needle passages at both sides to guide the needles into and out of knitting position, means to cause the lever normally to maintain one of said passages closed, and means to allow each needle introduced in said normally closed passage to automatically shift said lever to cause it to momentarily open said passage to allow a needle to enter therein.

2. In a. circular knitting machine an annular needle cylinder to guide the needles and a cam cylinder, said cylinders being rotatable relatively to each other, a ledge 011 said cam cylinder to support the butts of the needles and a plurality of knitting positions on said cam cylinder, a shiftable lever in front of each of said knitting positions to form alternate needle guiding passages at both sides, an adjustable block in said ledge to cooperate with said lever to close one of said passages, means to normally hold said lever in contact with said block and an abutment on the side of said lever facing said ledge to be operated by each needle passing between the ledge and the lever in order to momentarily lift the lever out of contact with said block to allow a needle butt to enter the normally closed passage.

3. In a circular knitting machine an annular needle cylinder to guide the needles, and a cam cylinder, said cylinders being rotatable relatively to each other, a ledge 011 said cam cylinder to support the butts of the needles and a plurality of knitting positions on said cam cylinder, a shiftable lever in front of each of said knitting positions to form alternate needle guiding passages at both sides of the lever, said lever being so arranged as normally to close the passage formed between the lever and the ledge in order to cause the needles to be lifted by the lever to an inoperative position, an abutment on the side of the lever facing said ledge to be operated by each needle butt which after shifting of the lever from said normal position is introduced in the space between the lever and said supporting ledge to be moved into the knitting position so as to lift the lever from said ledge after a definite relative rotation of the cylinders to allow a further needle butt to enter said passage, and means in front of each shiftable lever to restore those needles lifted to an inoperative level. into operative position in contact with the ledge.

V 4. In a circular knitting machine, an annular needle cylinder to guide the needles and a cam cylinder, said cylinders being rotatable relatively to each other, a ledge on said cam cylinder to support the butts of the needles and a plurality of knitting positions on said cam cylinder, a shiftable'lever in front of each of said knitting positions to form alternate needle guiding passages at both sides of the lever, said lever being pivoted at one end and arranged normally to engage said ledge by its free end to hold. one of said passages closed, a projection on that surface of said lever facing said supporting ledge to be operated by the needle butts momentzrily to shift the lever, the edge of the lever extendin between said free end and said projection being shaped as a curve permitting a number of needle butts to be enclosed between it and the ledge in the normal position of the lever.

5. In a circular knitting machine an annular needle cylinder to guide the needles and a cam cylinder, said cylinders being rotatable relatively to each other, a ledge on said cam cylinder to support the butts of the needles and at least two knitting positions on said cam cylinder, a shiftable lever in front said lever to momentarily shift the lever to allow a further needle butt to enter the space between the ledge and the lever.

In testimony whereof I have signed my name.

FRITZ ISRAELSON

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