EP3956507A1

EP3956507A1 - Flat bed knitting machine

Info

Publication number: EP3956507A1
Application number: EP20723944.3A
Authority: EP
Inventors: Andrea SALIMBENI
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-04-16
Filing date: 2020-04-09
Publication date: 2022-02-23
Also published as: WO2020213016A1

Abstract

Flat knitting machine comprising: - a supporting frame; - a first (1) and a second (2) needle bed to support and guide knitting needles (5) arranged symmetrically relative to a vertical plane (π); - a first front working carriage (10) and a second rear working carriage (20) adapted to move needles (5', 5'') respectively of said first (1) and said second (2) needle bed so that they protrude upward relative to a horizontal zero reference plane (Δ); - motor means for said working carriages (10, 20); - a yarn feed system, comprising yarn guides (6) and tensioning members; - a pulling system of a knitted fabric (T) being formed; - a command, control and programming unit, - at least a third needle bed (3) arranged above said horizontal zero reference plane (Δ); - at least a third working carriage (30), adapted to move the needles (5''') of said at least a third needle bed (3) so that they protrude below said horizontal zero reference plane (Δ), where said first (1) and second (2) needle bed coact with said at least a third needle bed (3) to form a knitted fabric (T).

Description

FLAT BED KNITTING MACHINE

Technical field

The invention is aimed at the field of textile machinery for hosiery and knitwear, and more in detail relates to a flat knitting machine.

Background art

In weft flat knitting machines, the needles, arranged in a straight line, move individually and are capable of picking up the yarn automatically (weft knitting).

The yarns are fed transversely to the needles as the weft in conventional knitting.

Flat knitting machines are composed of the following parts:

- a frame that forms the load-bearing structure of the entire machine;

- one or two needle beds, i.e. bars that support and guide the knitting needles;

- one or two carriages acting as moving part, provided with plates for the needle control locks that, by means of cams or triangles, impart to the needles of the respective needle beds the movements required to carry out the loop-forming cycle;

- motor means of the type comprising a motor, a speed variator and a motion transmission system to obtain an alternating linear movement of the carriages;

- a yarn feed system, comprising yarn guides, which slide on prismatic bars positioned above the needle beds, and tensioning members;

- a pulling system of the fabric being formed, comprising a comb that engages the start course of the knitted fabric and of a roller that subsequently draws, by means of a series of pressurized cylinders, the fabric being formed;

- a central programming unit that controls the sequence of the various operations required to produce the fabric, such as forming of the hem, machining of the body, execution of the locking courses to prevent dropped stitches, insertion of the separating course, etc., to ensure both continuity of weaving and separation of the individual fabric parts before manufacture.

More in detail, the needle bed is a flat bar that has a milled surface comprising parallel grooves inside which the needles slide.

The needle bed rests directly on the top part of the frame and can have different inclinations based on the machine model (a typical examples is an inclination of 45 degrees relative to the floor surface).

As stated, flat knitting machines can be equipped with one or two needle beds: those with only one needle bed only knit flat (plain) stitches, while those with two needle beds, one front and one rear, can knit flat and purl stitches simultaneously. In this case the two needle beds are mutually opposite, arranged symmetrically relative to a vertical plane. The needles are symmetrical, staggered so as to interpenetrate when they operate simultaneously. The space that separates the two needle beds is proportional to the gauge of the machine and is consequently also directly proportional to the size of the needles.

The machines are also provided with a device capable of shifting the rear needle bed to the left or right so as to obtain different weaves.

The carriage is the moving part of the machine that, by sliding (alternately from left to right and vice versa) on specific bars/guides, acts (via cams) on the butts of the needles previously selected making them carry out an upward/downward movement required to form the stitches.

Flat knitting machines with one needle bed only allow limited knitting processes to be carried out and for this reason they are not widely used today and are increasingly replaced by the generally more versatile machines with two needle beds.

However, knitting machines with two needle beds also have some limits and drawbacks essentially linked to the limited types of fabrics that can be produced, exclusively of single or double faced type, but without thickness.

Instead the market currently increasingly demands particular openwork, high thickness fabrics, worked with jacquard, intarsia, etc., which to date can only be created with special loom type knitting machines. Unfortunately, these loom machines are very complex, require lengthy preparation times and use large amounts of yarns, while only allowing minimum amounts of fabrics to be produced per unit time.

Presentation of the invention

The invention intends to overcome these limits, by producing a flat knitting machine that allows the production of high thickness three- dimensional fabrics, of shaped, crimped, jacquard, intarsia type, limiting the number of yarns and increasing and speeding up production.

These objects are achieved with a flat knitting machine comprising:

- a supporting frame;

- a first and a second needle bed to support and guide knitting needles arranged symmetrically relative to a vertical plane;

- a first front working carriage and a second rear working carriage adapted to move needles respectively of said first and said second needle bed so that they protrude upward relative to a horizontal zero reference plane;

- motor means for said working carriages;

- a yarn feed system, comprising yarn guides and tensioning members;

- a pulling system of a knitted fabric being formed;

- a command, control and programming unit,

characterized in that it comprises:

- at least a third needle bed arranged above said horizontal zero reference plane;

- at least a third working carriage, adapted to move the needles of said at least a third needle bed so that that they protrude below said horizontal zero reference plane,

where said first and second needle bed coact with said at least a third needle bed to form a knitted fabric.

According to a first aspect of the invention, said needles belonging to said first and second needle bed comprise a first and a second head and a first and a second butt.

Advantageously, said second head (52) is positioned below the first head (51 ) and the second butt (54) is positioned above the first butt (53).

Preferably, also said needles (5’”) of said at least a third needle bed (3) comprise a first (51 ) and a second (52) head and a first (53) and a second (54) butt.

According to a further aspect of the invention, said at least a third needle bed is arranged symmetrically relative to one of said first and second needle beds.

In a preferred variant of the invention, said machine comprises:

- a fourth needle bed, arranged symmetrically to said third needle bed relative to a vertical plane and also arranged above said horizontal zero reference plane;

- a fourth working carriage, adapted to move the needles of said fourth needle bed so that they protrude below said horizontal zero reference plane.

Advantageously, said fourth needle bed comprises needles comprising a first and a second head and a first and a second butt, so that the work can be passed back and forth between said fourth needle bed and said second needle bed positioned below it.

Even more advantageously, said fourth needle bed is arranged symmetrically relative to one of said first and second needle beds.

In a possible embodiment of the invention, said first, second, third and fourth needle beds are arranged substantially in an X. Advantageously, said first, second, third and fourth working carriages move simultaneously.

The main advantage of the invention consists in the possibility of producing a high thickness fabric, while working with a considerably smaller number of yarn cones.

Advantageously, the two conventional needle beds coact with at least a supplementary needle bed to carry out transfers and jacquard works between a needle bed located below the horizontal zero reference plane and a corresponding needle bed located above, and vice versa.

Even more advantageously, the two heads of the knitting needles allow certain special works, such as transfers or jacquard, to be implemented. In practice, the first head is used to create the stitch (as occurs currently) and the second is used to“park” or support the stitch created, in order to free the first head again so that it can continue to work. Therefore, the second head becomes a temporary support for the stitches that are not required for the subsequent knitting works. At the required moment, the second head will carry the work onto the first head, so that the two works can be joined.

The movement between the first main working head and the second stitch supporting head and vice versa is made possible by the double butt.

The presence of a third and a fourth needle bed, arranged symmetrically relative to said first and second needle bed, so that each needle bed positioned below the horizontal zero reference plane works with a respective needle bed arranged above the horizontal zero reference plane makes it possible to work and enables the work produced to descend vertically.

The preparation times of a flat knitting machine according to the invention are considerably lower relative to the preparation times of the loom machines currently used to produce high thickness fabrics: such short times makes it possible to produce even small amounts of special fabrics, continuously varying pattern, type, colors, etc....

With the machine according to the invention it is advantageously possible to produce, in addition to fabric, also high thickness articles shaped directly in the machine, high thickness crimped, high thickness jacquard, high thickness intarsia, etc.

In general, the machine according to the invention allows a drastic reduction in working times, considerably increasing production with a consequent economic benefit.

Brief description of the drawings

The advantages of the invention will be more apparent in the following description, in which preferred embodiments are described purely by way of non-limiting example, and with the aid of the figures, wherein:

Fig. 1 shows, in cross section along a vertical plane, a portion of a flat knitting machine with two needle beds according to the prior art;

Fig. 2 shows, in cross section schematized along a vertical plane, a portion of a flat knitting machine according to the invention;

Fig. 3 shows, in cross section along a vertical plane, a portion of a flat knitting machine according to a possible variant of the invention;

Fig. 4 shows, in a side view, a knitting needle for the machine according to the variant of the invention of Fig. 3;

Figs. 5 and 6 show, schematically, the stitches of two knitted fabrics that can be produced with the flat knitting machine according to the invention.

Detailed description of a preferred embodiment of the invention With particular reference to Fig. 1 , a portion of flat knitting machine with two needle beds according to the prior art is illustrated.

Said flat knitting machine substantially comprises:

- a frame constituting the load bearing structure of the entire machine;

- two needle beds 1 , 2, consisting of grooved rectilinear plates that support and guide the knitting needles 5’, 5”;

- two carriages, a first front carriage 10 and a second rear carriage 20, acting as moving part that by means of cams or triangles impart to the needles 5’, 5” of the respective needle beds 1 , 2 the movements required to carry out loop-forming cycle;

- a yarn feed system, comprising yarn guides 6, which slide on prismatic bars 7 positioned above the needle beds 1 , 2, and tensioning members;

- a pulling system of the fabric being formed, consisting of a comb (not illustrated) that draws the fabric being formed;

- motor means of the mechanisms of the machine;

- a command, control and programming unit.

Said carriages 10, 20 thus have the function of selecting the needles 5’, 5” and imparting to them the lifting and lowering movements to form the stitch.

Each carriage 10, 20 slides on guides by means of bearings or slides and carries out an alternating movement from right to left and vice versa.

Locks, or feeds, are mounted on each carriage 10, 20 to support cams adapted to lift and lower the needles 5’, 5” allowing the stitch to be formed.

As is apparent from Fig. 1 , the needle beds 1 , 2 are two, arranged symmetrically relative to a vertical plane TT, and inclined with an angle a of around 45° relative thereto.

Said first needle bed 1 is at the front, while said second needle bed 2 is at the rear with reference to said vertical plane TT.

With particular reference to Fig. 2, this instead illustrates the preferred variant of the solution according to the invention, which provides for a third 3 and a fourth 4 needle bed, i.e., two further supplementary needle beds.

Said third needle bed 3 is at the front, while said fourth needle bed 4 is at the rear, again with reference to said vertical plane TT.

Said third 3 and fourth 4 needle beds are also arranged symmetrically relative to a vertical plane p and symmetrically, relative to said first 1 and second 2 needle bed, above said horizontal zero reference plane D.

Said first 1 , second 2, third 3 and fourth 4 needle bed are arranged substantially in an X. Said flat knitting machine thus comprises a third front working carriage 30 and a fourth rear working carriage 40 adapted to move the needles 5’”, 5”” respectively of said third 3 and said fourth 4 needle bed.

The two front carriages 10, 30 and the two rear carriages 20, 40 are respectively connected by means of bridges 8, 9, and in general said first 10, second 20, third 30 and fourth 40 working carriages move in a block and simultaneously.

With reference to Figs. 3 and 4, these illustrate a variant of the machine with more than two needle beds even more advantageous and high performance.

To be able to produce a shaped knitted accessory, worked with three-dimensional fabric, crimped, openwork, jacquard and with intarsia on both sides of the fabric, and hence to be able to produce a high thickness knitted fabric, the machines with more than two needle beds require to carry out transfers and work between and with the needle beds that are respectively below and above said horizontal zero reference plane. By equipping the needle beds with known knitting needles with a single head, comprising a hook and a lever, and with only one butt, these processes are slow and difficult to carry out.

In the variant of Fig. 3, the flat knitting machine comprises four needle beds (1 , 2, 3, 4), where the needles (5’, 5”) of said first (1 ) and second (2) needle bed comprise a first (51 ) and a second (52) head and a first (53) and a second (54) butt. With reference to Fig. 4 this illustrates a generic needle 5 with two heads useful for the embodiment of the invention.

Said needle comprises a first main working head 51 and a second parking or supporting head 52; a first butt 53 adapted to appropriately lift said first main working head 51 and a second butt 54 adapted to appropriately lift said second parking or supporting head 52.

The second head 52 is positioned below the first head 51 and the second butt 54 is positioned below the first butt 53.

In a first variant said needles 5’ and 5” belonging to said first 1 and second 2 needle bed are structured in the same way as said needle 5.

In a more complex variant, the needles 5’”, 5”” are also structured in the same way as said needle 5.

This type of needle 5 helps and causes the first needle bed 1 to work with the third needle bed 3 above and the second needle bed 2 to work with the fourth needle bed 4 above.

The head 51 substantially only serves as a support while the head 52 works actively and the work is passed back from the head 51 to the head 52, allowing work to take place between the needle bed above and the needle bed below, thus making it possible to produce the stitch and make it descend vertically.

As stated above, with reference to Figs. 5 and 6, these illustrate the stitches of two knitted fabrics produced with the flat knitting machine according to the invention and according to two different working processes that can be carried out with this machine.

Production of the high thickness fabric of Fig. 5 includes the following working steps with needle/needle section and needle beds moved in transfer:

- first needle bed work, feed one;

- first and second needle bed work, feed three;

- second needle bed work, feed two;

- transfer of the yarn from the first needle bed to the third needle bed and from the third needle bed to the first;

- transfer of the yarn from the second needle bed to the fourth needle bed and from the fourth needle bed to the second.

Production of the high thickness fabric of Fig. 6 includes the following working steps:

- first needle bed work,

- third and fourth needle bed work;

- second needle bed work;

- third and fourth needle bed work with binding for high thickness fabric plus transfer.

Advantageously, with the flat knitting machine according to the invention it is possible to produce complex works and stitches that are different from one another and with several layers.

Purely by way of non limiting example, it is possible to produce fabrics structured as follows:

A) three-layer fabric (open or bound):

- first honeycomb-like openwork layer;

- second double jacquard (inner) layer with wording;

- third flat (plain) layer; B) four-layer fabric (open or bound):

- first honeycomb-like openwork layer;

- second floating jacquard (inner) layer with wording;

- third (inner) layer with wording on the back opposite the second floating jacquard layer;

- fourth honeycomb-like openwork (outer) layer on the back.

Claims

1. Flat knitting machine comprising:

- a supporting frame;

- a first (1 ) and a second (2) needle bed to support and guide knitting needles (5) arranged symmetrically relative to a vertical plane (TT) ;

- a first front working carriage (10) and a second rear working carriage (20) adapted to move the needles (5’, 5”) respectively of said first (1 ) and said second (2) needle bed so that they protrude upward relative to said horizontal zero reference plane (D);

- motor means for said working carriages (10, 20);

- a yarn feed system, comprising yarn guides (6) and tensioning members;

- a pulling system of a knitted fabric (T) being formed;

- a command, control and programming unit,

characterized in that it comprises:

- at least a third needle bed (3) arranged above said horizontal zero reference plane (D);

- at least a third working carriage (30), adapted to move the needles (5’”) of said at least a third needle bed (3) so that they protrude below said horizontal zero reference plane (D),

where said first (1 ) and second (2) needle bed coact with said at least a third needle bed (3) to form a knitted fabric (T).

2. Flat knitting machine according to claim 1 , characterized in that characterized in that said needles (5’, 5”) belonging to said first (1 ) and second (2) needle bed comprise a first (51 ) and a second (52) head and a first (53) and a second (54) butt.

3. Flat knitting machine according to claim 2, characterized in that said second head (52) is positioned under the first head (51 ) and the second butt (54) is positioned above the first butt (53).

4. Flat knitting machine according to claim 2 or 3, characterized in that said needles (5’”) of said at least a third needle bed (3) comprise a first (51 ) and a second (52) head and a first (53) and a second (54) butt.

5. Flat knitting machine according to claim 1 , characterized in that said at least a third needle bed (3) is arranged symmetrically relative to one of said first (1 ) and second (2) needle beds.

6. Flat knitting machine according to claim 1 , characterized in that it comprises:

- a fourth needle bed (4), arranged symmetrically to said third needle bed (3) relative to a vertical plane (TT) and also arranged above said horizontal zero reference plane (D);

- a fourth working carriage (40), adapted to move the needles (5””) of said fourth needle bed (4) so that they protrude below said horizontal zero reference plane (D).

7. Flat knitting machine according to claim 6, characterized in that said fourth needle bed (4) comprises needles (5””) comprising a first (51 ) and a second (52) head and a first (53) and a second (54) butt, so that the work can be passed back between said fourth needle bed (4) and said second needle bed (2) positioned below it.

8. Flat knitting machine according to claim 6, characterized in that said fourth needle bed (4) is arranged symmetrically relative to one of said first (1 ) and second (2) needle beds.

9. Flat knitting machine according to claims 5 and 8, characterized in that said first (1 ), second (2), third (3) and fourth (4) needle beds are arranged substantially in an X.

10. Flat knitting machine according to claims 1 and 6, characterized in that said first (10), second (20), third (30) and fourth (40) working carriages move simultaneously.