US3007326A

US3007326A - Flat warp knitting machines

Info

Publication number: US3007326A
Application number: US18116A
Authority: US
Inventors: Porter Allan William Henry
Original assignee: HOBOURN F N F Ltd
Current assignee: HOBOURN F N F Ltd; Hobourn-Fnf Ltd
Priority date: 1959-04-14
Filing date: 1960-03-28
Publication date: 1961-11-07
Anticipated expiration: 1978-11-07
Also published as: GB874717A; CH364862A

Description

Nov. 7, 1961 A. w. H. PORTER 3,007,326

FLAT WARP KNITTING MACHINES Filed March 28, 1960 United States Patent 3,007,326 FLAT WARP KNITTING MAtIIWES Allan William Henry Porter, Burton-on-Trent, England, assignor to Hobourn-F.N.lF. Limited Filed Mar. 28, 1960, Ser. No. 18,116 Claims priority, application Great Britain Apr. 14, 1959 8 tjlaims. (Cl. 66-109) This invention relates to sinker assemblies for fiat warp knitting machines of the kind which include a straight row of reciprocating hooked needles between which the sinkers, which consist of fiat plates, are situated.

The sinkers are reciprocated to and fro so that nebs on their upper edges are moved between a first position in which they lie across the row of needles and fit between the individual needles and a second position in which they are withdrawn from between the needles and lie in front, that is on the open sides, of the needle hooks.

The sinker nebs are used, during the course of the knitting cycle, to hold down previously knitted loops around the shanks of the needles as the needles rise between the sinkers.

A portion of the sinker adjacent the neb usually forms a knock-over edge which pushes the loops lying around the shanks of the needles upwards off the tops of the needles as the needles descend again later in the knitting cycle.

The portions of the sinkers which form the knock-over edges usually extend in a direction transverse to the row of needles, but in some cases the knock-over edges have been formed by a die-cast bar which extends parallel to the row of needles and into which the ends of the sinkers adjacent the nebs are cast to fix them together. This form of longitudinal knock-over edge has not proved very satisfactory because the die-cast bars are necessarily soft and gnooves are cut in them by the threads. The threads eventually tend to jam in these grooves.

According to the present invention a sinker assembly for a fiat warp knitting machine comprises a row of flat faced sinkers mounted face to face with spaces between them, each sinker having a neb projecting from one edge and pointing towards one end of the sinker, and a roller mounted between each adjacent pair of sinkers and adjacent the ends of the sinkers towards which the nebs point, the rollers being rotatable about a common axis extending along the row of sinkers.

The rollers form a knock-over edge which extends in a direction parallel to the row of needles and this has certain advantages over transversely extending knock-over edges on the sinkers themselves. Because the rollers turn they are not cut by the threads and so the disadvantages of the knock-over edge formed by a die-cast bar are overcome. To ensure that no cutting takes place the rollers may be made of hardened steel or ceramic material.

The knitted fabric as it is produced by the knitting elements is drawn oif in a direction away from the backs of the needle books by the draw-off rollers, or other drawofi mechanism of the knitting machine, and therefore passes directly across the longitudinal knockover edge. This provides a more even drag on the knitted material as it is drawn olf than is provided by transverse edges over which the fabric is drawn in a skew direction.

Preferably, each roller consists of a circular disc having a central circular hole and each roller is carried on a circular rod having a diameter substantially less than that of the hole so that the disc is movable in a plane at right angles to the row of sinkers. With this arrangement, the sinker assembly can be fixed in the knitting machine in such a way that the back of the needle hook comes into contact with the circular disc as the needles descend and the sinker nebs are withdrawn from between the needles; that is as the stage or knock-over is approached in the ice,

knitting cycle. The contact of the backs of the hooks of the needles with the discs, tends to rotate the discs on their supporting rods. Because the holes in the discs are greater than the diameter of the rod, the discs tend to roll on the rod and this lifts the part of the periphery of the disc remote from that which is in contact with the back of the needle. This lifting of the disc raises the part of the fabric which has just been knitted and which passes over the top of the disc, and greatly assists the knock-over operation.

Two examples of sinker assemblies constructed in accordance with the invention are illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective view of one assembly;

FIGURE 2 is a cross-section through a part of the assembly shown in FIGURE 1;

FIGURE 3 is a perspective View of part of another assembly; and

FIGURE 4 is an elevation of the assembly as seen in the direction of the arrow IV in FIGURE 3.

The'assembly shown in FIGURE'I comprises a series of sinkers consisting of flat plates 1 fixed together face to face by being cast into a light metal block 2. Each plate 1 has a projecting neb 3 on its upper edge. The plates 1 are fixed together at their left-hand ends, as seen in FIGURES 1 and 2 of the drawings, by a rod 4 which passes through a hole in each of the plates.

Mounted on the rod 4 between each adjacent pair of plates 1 is a circular disc 5 having an internal opening 6 with a diameter equal to approximately twice that of the rod 4.

In use in a fiat warp knitting machine, the assembly is fixed to a sinker bar as described in my co-pending appli cation Serial No. 18,039, filed March 28, 1960, now Patent No. 2,988,906. When this is done the sinker assembly is in the position shown in FIGURE 2 of the drawings relative to a needle 7 as the needle and sinker reach a stage in the knitting cycle shortly before knock-over takes place.

From the position shown in full lines in FIGURE 2 of the drawings, the back 8 of the hook 9 of the needle 7 moves downwards into the position shown in chain-dotted lines at 8'. As this happens, the part of the disc 5 in contact with the back 8 is pushed downwards and this rolls the disc 5 on the rod 4 so that the upper part of its periphery is raised into the position shown at 5. This upward movement of the top of the periphery of the disc 5, which forms the knock-over edge of the sinker, lifts the knitted fabric, and with it the last knitted loop lying around the shank of the needle '7, relatively to the needle 7 and expedites the knock-over of the loop.

The discs 5 shown in FIGURES l and 2 of the drawings have cylindrical peripheries and they are a close sliding fit between the plates 1.

In the second example illustrated in FIGURES 3 and 4 of the drawings, the discs 5 are substituted by rollers 10 which are a close rotatable fit on the rod 4. As shown in FIGURE 4 of the drawings, the rollers 10 have grooved peripheries 11. Since the rollers 10 are a close fit on the rod 4 they are only capable of rotating and cannot roll as do the discs 5. Because of the grooves in their peripheries 11, however, they locate and space the threads which pass over them accurately along the rod 4.

I claim:

1. A sinker assembly for a flat warp knitting machine, the assembly comprising a now of flat faced sinkers mounted face to face*with spaces between them, each sinker having a neb projecting from one edge and pointing towards one end of the sinker, and a roller mounted between those ends of each adjacent pair of sinkers towards which the nebs point, the rollers being rotatable about a common axis extending along the row of sinkers.

2. An assembly according to claim 1, in which each roller consists of a circular disc having a central circular hole and is carried on a circular rod having a diameter substantially less than that of the hole so that the disc is movable in a plane at right angles to the row of sinkers.

3. A sinker assembly for a flap warp knitting machine, said assembly comprising a plurality of flap elongated sinker plates, each of said plates comprising a first end portion, a second end portion, a longitudinal edge extending between said end portions, and a neb portion projecting from said edge intermediate said end portions and pointing towards said first end portion, means interconnecting said second end portions of said plates whereby said plates are fixed together in a row in spaced apart face to face relation with said neb portions in alignment with each other, a plurality of rollers, one roller being located between the first end portions of each adjacent pair of said plates, and means carried by said sinker plates on which said rollers are mounted for rotation about a common axis.

4. A sinker assembly according to claim 3, wherein each of said rollers consists of a circular disc having a central circular hole and said mounting means consists of a circular rod extending through said first end portions and through said holes, said holes being of greater diameter than said rod whereby said discs are movable in a plane at right angles to said row.

5. An assembly according to claim 3, in which said rollers each have a peripheral groove.

6. In a fiat warp knitting machine including a row of hooked needles the improvement consisting of a sinker assembly comprising a plurality of flat elongated sinker plates one between each adjacent pair of said needles, each of said plates comprising a first end portion, a second end portion, a longitudinal edge extending between said end portions and a neb portion projecting from said edge intermediate said end portions and pointing towards said first end portion, said nebs being located on the open sides of said needle hooks, means interconnecting said second end portions of said plates whereby said plates are fixed together in a row in spaced apart face to face relation with said neb portions in alignment with each other, a plurality of rollers, one roller being located between said first end portions of each adjacent pair of said plates, and means carried by said plates on which said rollers are mounted for rotation about a common axis lying on the closed sides of said needle hooks.

7. A fiat warp knitting machine according to claim 6, wherein each of said rollers consists of a circular disc having a central circular hole and said mounting means consists of a circular rod extending through said first end portions and through said holes, said holes being of greater diameter than said rod whereby said discs are movable in a plane at right angles to said row.

8. A fiat warp knitting machine according to claim 6, in which said rollers each have a peripheral groove.

References Cited in the tile of this patent UNITED STATES PATENTS 2,682,163 Stat]? et a1 June 29, 1954 2,749,730 Noe June 12, 1956 FOREIGN PATENTS 147,056 Great Britain Dec. 20, 1920