FR2722515A3 - Fabric holding down mechanism useful for circular knitting machine - Google Patents

Abstract

A cylinder and dial double knot knitting machine has a series of presser sinkers (3) reciprocated by cam means radially relative to the cylinder needles (2). The sinkers (3) prevent the fabric (5) from rising with the needle when the dial needles are immobile. A nose (32) on each sinker (3) cooperates with the top face (40) of the fabric forming member (4) leaving a gap equal to the thickness of the knitted fabric.

Description

Mechanism for holding the fabric down for knitting machines

  The present invention relates to a mechanism for holding the fabric down which prevents the fabric from being lifted by the

  cylinder needles during the knitting operation.

  British patent application GB 2,199,341 discloses a circular knitting machine comprising a plurality of needles which move longitudinally on the cylinder to effect knitting, and a ring placed around the cylinder needles to be driven with them . To prevent the fabric from being lifted, support plates down are provided and mounted on the ring

  and they move radially with respect to the needle cylinder.

  Another knitting machine is known for forming fabric-

  sponge, disclosed in British Patent No. 1,534,575, entitled "Improved double loop knit fabric, machine and method", which comprises a plurality of needles to which hooks are pivotally attached which move between an open position and a position closed, lifting means for actuating the needles and pairs of plates intended to cooperate with the needles to form loops. The two plates of the same pair have one a groove and the other a cornice. These plates are not used for

keep the fabric down.

  The present invention relates to double knitting machines. Conventional double knitting machines are commonly used for knitting plain cotton fabrics having no embossed patterns and, therefore, the tray and cylinder needles are controlled to perform complete knitting cycles by a knitting operation of stitches, and the tray and cylinder needles of each knitting unit will retain each other, i.e. the fully extended tray needles will press on the edges of the fabric to prevent the fabric from being lifted during the rising point race. These double knitting machines are now commonly used for

  knit fabrics with embossed patterns on both sides.

  When knitting such fabrics, the cylinder needles (or platter needles) can be held stationary, causing the fabric to lift during the upstroke stroke. To eliminate this problem, the present applicant has proposed a set of plates intended for double knitting machines, as disclosed in French patent n 9,313,888, entitled "Double knitting machine for knitting a constructed fabric". The set of plates is installed in the casing of the double knitting machine corresponding to a respective cylinder needle and comprises a fixed plate for supporting and guiding the knitted fabric and a press plate placed in parallel with the fixed plate coming and going. radially for

  press the knitted fabric during each rising stitch of the cylinder-

  of needles to prevent the knitted fabric from being lifted by the

  cylinder guille. This set of decks structure is function-

  nelle; however, it is a complex structure since it includes

  a fixed plate and a press plate.

  The present invention constitutes an improvement in the provision

  sition disclosed in French Patent No. 9,313,888, entitled "Machi-

  double knitting to knit a constructed fabric. "

  The present invention eliminates the fixed plate from the set of plates. While only the press plate is installed, the same function is obtained. When the press plate is moved radially back and forth, the projecting head of the press plate will move

  up to an anterior limiting position, located above the upper edge

  of the fabric forming surface of the knitting machine, at a distance equal to the thickness of the already knitted fabric, during the rising stitch stroke of the respective cylinder needle and, therefore,

  the knitted fabric cannot be lifted by the cylinder needle.

  The present invention will be better understood on reading the

  following detailed description taken in conjunction with the drawings

  annexed, in which: FIG. 1 is a partial view of a double knitting machine according to French patent n 9,313,888; Figure 2 is an elevational view of a press platen according to the present invention; FIG. 3 shows the projecting head of the plate which presses on the knitted fabric during the rising point stroke of the cylinder needle according to the present invention; Figure 4 shows the cylinder needle in the retracted position and the press plate removed from the fabric, according to the present invention; Figure 5 is a plan view of the double knitting machine according to the present invention, which shows the position of the press plate; and

  FIG. 6 is an elevation view of FIG. 5.

  If we refer to Figures 5 and 6, the knitting machine

  circular includes a series of tray needles 8, arranged radially

  in a single horizontal plane, and a series of cylinder needles

  dre 2 arranged vertically and in correspondence with the series of tray needles. Tray needles 8 and

  cylinder 2 constitute a series of knitting units. When the ma-

  china knitting works, the tray needles 8 and the cylinder needles 2 are respectively moved back and forth at right angles and intersect around the top 40 of a surface 4 for forming the fabric; therefore, loops are respectively formed from the wire fed through the wire hole 6 and made into fabric. The fabric 5 thus formed is then gradually sent downward across the surface

4 of tissue formation.

  The main feature of the present invention is the installation of a mechanism for holding the fabric down in the circular knitting machine. intended to prevent the fabric 5 from being lifted during the knitting operation. The mechanism for holding the fabric down comprises a pressing plate 3 which is moved horizontally back and forth, a cam 10 fixedly mounted on the needle cylinder of the knitting machine, which controls the

  displacement of the press plate 3, and the top 40 of the surface above

  mentioned tissue formation. The press plate 3 is placed in a corresponding radial slot 11 of the knitting machine and is moved when the needle cylinder of the knitting machine is rotated. The pressing plate 3 comprises, in the middle of its upper face, a vertical guide strip 31, inserted in a track placed on the lower face of the cam 10. When the cam 10

  moves, the pressing plate 3 moves radially back and forth.

  As shown in Figure 2, the press plate 3 further comprises a projection head 32, placed horizontally at its front end. When the pressing plate 3 moves forward to its anterior limit, the projecting head 32 of the plate is above the top 40, being spaced from the top 40 by a distance 320 approximately equal to the thickness of the fabric. 5 (See the

figure 3).

  If we refer to Figures 3 and 4, when the cylinder needle

  dre 2 is brought back during its downward point stroke, the projecting head 32 of the pressing plate 3 is brought back; when the cylinder needle 2 is moved vertically upwards during its rising point stroke, the projecting head 32 of the pressing plate 3 is moved to the anterior limit above the top and presses on the knitted fabric 5 Therefore, the knitted fabric 5 will not be lifted by the cylinder needle 2 during the knitting operation.

Claims (1)

CLAIM   Mechanism for holding the fabric down for a double knitting machine of the type comprising a series of horizontal plate needles (8) and a series of vertical cylinder needles (2), moved back and forth by a cam drive of the machine for knitting a double-sided fabric on a fabric-forming surface (4), said fabric-holding mechanism being characterized in that it comprises a series of displaced press plates (3) radially back and forth with respect to said series of cylinder needles (2), each press plate (3) having a projecting head (32) placed horizontally at its anterior end, said projecting head (32 ) of the stage being moved to an anterior limit position situated above the edge   upper (40) of said tissue forming surface (4), at a distance   this (320) equal to the thickness of the fabric (5) already knitted during the race   rising point of the respective cylinder needle (2), which prevents   that the knitted fabric is not lifted by the cylinder needle (2).