US3898819A

US3898819A - Warp knitting machine

Info

Publication number: US3898819A
Application number: US178505A
Authority: US
Inventors: Siegfried F Brand
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-07-01
Filing date: 1971-09-07
Publication date: 1975-08-12
Anticipated expiration: 1992-08-12

Abstract

A warp knitting machine, knitting process and the fabric produced thereby, the machine employing rigid guide needles, sinkers and presser which cooperate with two needle sets mounted on independent needle bars. The needles of one bar are aligned with the needles of the other bar in a straight line across the width of the machine. The same spacing and total number of stitch needles and rigid guide needles as in a conventional single needle bar machine is provided, although each needle bar has less than the total number of needles of a conventional machine. The needle bars are movable independently in cooperation with the guide needles and sinkers, thereby providing a greater variety of patterns. The knitting motion preferably requires in any sequence at least one alternate and one simultaneous rise and fall movement of each of the two needle bars. The resultant fabric may have at least some of the stitches arranged in diagonal course lines, may have tuck stitches and may have both tight and loose stitches arranged side by side.

Description

United States Patent [1 1 Brand I 1 Aug. 12, 1975 WARP KNITTING MACHINE [76] Inventor: Siegfried F. Brand, RFD l, Hayes Dr., Yorktown Heights, NY. 10598 221 Filed: Sept. 7, 1971 21 Appl. No.: 178,505

Related US. Application Data [63] Continuation-impart of Ser. No. 838,075, July 1,

Primary ExaminerRonald Feldbaum Attorney, Agent, or FirmRobert J. Blanke 5 7 ABSTRACT A warp knitting machine, knitting process and the fabric produced thereby, the machine employing rigid guide needles, sinkers and presser which cooperate with two needle sets mounted on independent needle bars. The needles of one bar are aligned with the needles of the other bar in a straight line across the width of the machine. The same spacing and total number of stitch needles and rigid guide needles as in a conventional single needle bar machine is provided, although each needle bar has less than the total number of needles of a conventional machine. The needle bars are movable independently in cooperation with the guide needles and sinkers, thereby providing a greater variety of patterns. The knitting motion preferably requires in any sequence at least one alternate and one simultaneous rise and fall movement of each of the two needle bars. The resultant fabric may have at least some of the stitches arranged in diagonal course lines, may have tuck stitches and may have both tight and loose stitches arranged side by side.

10 Claims, 7 Drawing Figures PATENTED AUG 1 2 I975 SHEET WARP KNITTING MACHINE BACKGROUND OF THE DISCLOSURE This invention which is a continuation-in-part application of copending application Ser. No. 838,075, filed July 1, 1969, relates to warp knitting, and more particularly to needle positioning systems in warp knitting.

Since the warp knitting technique provides the fastest means of making yarn into fabric, it has come to be utilized primarily for the mass production of staple textile at the greatest speeds and at the lowest costs. The development of high speed equipment had to be done at the expense of versatility and variety and has created a market for warp-knits, in which a few basic fabrics sell in volume and many novelties in short yardages.

As a consequence there has developed an increasing interest in machines which depart from the standard design and permit the production of new and distinctly different basic fabrics. Even if such devices necessitate decreased speeds and increased costs, they will be fully justifiable and desirable from a standpoint of diversification, so long as the resultant product is unique, cannot be produced by any other practical and more efficient process and the fabric is both attractive and functional in terms of end use.

A conventional warp knitting machine pulls yarn from two beams on the machine and by stitching joins the yarns of one beam with parallel yarn ends of the other beam. Typically, there are two guide bars extending across the width of the machine and a guide needle on the front bar is provided for each yarn end drawn from one beam. A similar guide needle is provided on a separate guide bar for the corresponding yarn end of the other beam.

In a conventional knitting machine, the stitch needles are mounted in a single needle bar, which is movable upwardly and downwardly with respect to a row of horizontal sinkers extending across the width of the machine.

Knitting machines having split needle bars and rigid guide needles are known, such machines being employed to produce dense or tightly constructed fabrics or to prevent laddering or splitting or to facilitate the production of jacquard patterns through the use of drop pins. Representative of the split needle bar machines of the prior art are German Pat. No. 243,433 issued Feb., 1912, and German Pat. No. 106,618, issued Dec., 1899. These prior art split needle machines having been designed to rapidly produce dense fabric have, as in the case of German Pat. No. 106,618, extremely close spacing of the stitch needles. such an arrangement would ordinarily prevent guide needles from passing between the stitch needles, however, the patented apparatus is permitted to function by employing one guide needle for every pair of stitch needles and adjusting the movement so that the guide needles use the space left unoccupied by the lowered or dormant stitch needles; that is to say, only one split needle bar may be in the raised position.

German Pat. No. 243,433 which has as an objective, the rapid fabrication of dense fabric employs slip needle bars which rise in alternation but fall simultaneously in order to speed production. It can therefore be seen that these machines are suitable for the rapid production of dense fabrics, but lack the flexibility necessary for the production of new fabric designs. i

The movements of the guide needles, sinkers and needle bars of a conventional single needle bar machine are controlled by cams, cam shafts, crank shafts, pattern wheels, chain links, or other positive displacement mechanisms. Thus, variations in patterns is limited by the degree of changes that can be made in the motions of these components.

SUMMARY OF THE INVENTION It is the object of this invention to provide method and apparatus for producing novel fabrics by warp knitting.

Another object of this invention is to provide novel warp knitted fabrics.

It is a further object in this invention to provide method and apparatus for readily and conveniently changing stitch patterns in a warp knitting machine.

These objects are accomplished in accordance with a preferred embodiment of the invention by providing two stitch needle bars on a warp knitting machine, with the bars being movable independently by an eccentric device. Needles in both bars face in the same direction, fall into the same line extending transversely of the machine and move upwardly and downwardly along parallel axes. The machine is provided with rigid or nondeflectable guide needles, one guide needle being provided for each stitch needle, even though at times, not all of the stitch needles may be threaded, depending on pattern requirements. The total number of stitch needles is the same or less than the corresponding single needle bar on a conventional machine, but variations in the sequence of needles arranged in each of the needle bars provides a variety of stitch patterns that is not possible with conventional machines. The two needle bars are preferably driven by an eccentric device in a manner so that they may be raised both alternately and together in any sequence. When both needle bars are in the raised position, the rigid guide needles may still pass between the stitch needles. The two needle bars preferably have separate warp yarn feed and tension controls. If desired, the eccentric device may be arranged such that tuck stitching is produced. When tuck stitching, both needle bars go up at the same time, but one bar does not come down to the point of cast off, thereby holding individual yarns on the hook o the needle. When the needle with the held yarn is raised again, it will produce a stitch with two yarn ends. A tuck stitch may then be made on the other bar to produce a pattern. When tuck stitching, it is preferred that a latch needle be employed.

The basic fabric produced by this invention is a single faced warp knit fabric wherein none of the underlaps cross each other, the fabric having a greatly diminished wale rib and a course line that appears offset rather than straight. The fabric may also have tuck stitches and have both tight and loose stitches knitted side-byside and have at least some of the stitches arranged in diagonal course lines.

DESCRIPTION OF DRAWINGS This preferred embodiment is illustrated in the accompanying drawings in which:

FIG. 1 is a schematic view of the needle bars and associated conventional machine structure cooperating with the needle bar structure of this invention;

FIG. 2 is a perspective view of the needle bars;

FIG. 3 is a perspective view of the components shown in FIG. 1, but with the front needle bar lowered;

FIG. 4 is a schematic view of a conventional stitch pattern utilizing a single needle bar;

FIG. 5 is a schematic view of a stitch pattern utilizing the two needle bars of this invention;

FIG. 6 is another schematic view of the stitch pattern utilizing the two needle bars of this invention; and

FIG. 7 is a schematic view of still another stitch pattern utilizing the two needle bars of this invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT A conventional warp knitting machine has two or more beams mounted on the top or back of the machine frame. A sheet of parallel yarns is wound on each beam, each yarn end from one beam passes through the eye of a corresponding guide needle on the guide bar. Referring to FIG. 1, guide bars 2 and 4 are shown schematically. The guide bars are movable in unison about a shaft extending transversely of the machine. This vertical swinging movement of the guide bars is controlled by a cam shaft or other suitable means. The entire guide bar mounting also moves laterally of the machine frame for wrapping the yarn around the needles. This lateral motion is known as a shog.

Rigid guide needles 6 and 8 are secured on the guide bars 2 and 4 respectively. Typically, a plurality of rigid guide needles are formed as a unit and secured on the guide bar. Below the rigid guide needles 6 and 8, sinkers 10 are mounted on a sinker bar 12 that extends across the width of the machine. The sinker bar is movable forwardly and rearwardly. The sinkers 10 are thin metal blades which extend parallel to each other across the width of the machine. Directly above the sinker bar 12, a presser bar 14, which also extends across the width of the machine, is mounted for inward and outward movement. A presser edge 16 extends forwardly from the presser bar 14.

A pair of needle bars 18 and 20 are provided below the sinker bar 12. Each needle bar has a series of needles mounted on the opposed face of the bars. The needles 22 of the rear needle bar 18 are bent forwardly and the needles 24 are bent rearwardly adjacent their base, so that all of the needles are aligned, as shown in FIGS. 1 and 2. Beard needles are shown in FIGS. 1 and 2, but, of course, latch needles could also be utilized in accordance with this invention and are preferred when tuck stitching. The needle bars 18 and 20 are supported on

arms

26 and 28. The

arms

26 and 28 are displaced vertically by cams or other suitable means which are coordinated with the motion of the rigid guide needles, sinker bar and presser bar. The method and structure utilized to control movements of the needle bars 18 and 20 are substantially the same as those currently utilized for controlling conventional single needle bar machines, but the movements of the

bars

18 and 20 are separately controlled and are capable of lifting the bars either alternately or together.

As shown In FIG. 3, the needles 22 of the rear needle bar 18 are positioned between pairs of sinkers 10, while the needles 24 of the front needle bar 20 are positioned in the alternate spaces between the sinkers 10. The front needle bar 20 is shown in a lowered position in FIG. 3, so that the needles 24 do not catch the yarn during the underlaps of the guide bars. Thus, the front needle bar 20 remains at rest, while the rear guide bar 18 executes the normal motion, as if it had the full complement of needles and stitching is carried out on the needles 22 by relative motions of the guide needles 6 and the sinkers 10. At the completion of the stitch on the rear needle bar 18, it is lowered to an inoperative position and the front needle bar 20 is raised into an operative position and moved according to conventional practice for the formation of stitches on the needles 24. The needle bar 20 then returns to its lowered position and the cycle is repeated. Since the needles of the bar which is lowered are not operative for the formation of stitches, the motion of the associated guide needles does not produce a stitch, although a stitch is produced on the needles that are raised.

A typical fabric knitted on a warp knitting machine is shown in FIG. 4. The needle positions are indicated by dots. It can be seen that the yarn loops are formed along straight lines that correspond to the needle positions of the single needle bar of a conventional knitting machine. In FIG. 5, a fabric knitted on apparatus according to this invention is shown. The yarn loops are offset in adjacent courses to produce novel patterns.

In FIG. 6, a fabric knitted on the apparatus of this invention having the preferred knitting motion is shown, the preferred motion requiring, at least one alternate and one simultaneous rise and fall movement.

In FIG. 7 a fabric knitted on the apparatus of this invention having needle bars set 1 to 1 and two guide bars drawn 1 to l is shown. The fabric is a simple basic stitch 45 bias course line fabric having high flex and recovery.

For simplicity, the

needles

22 and 24 are arranged alternately in the rear bar 18 and the front bar 20. Other arrangements of the needles, of course, can be used, although both bars together at any time may contain no more than the total number of needles present in a full-set bar of the particular gauge. For example, the rear needle bar 18 may have a needle at every other location, as shown in FIG. 3, and the needle bar 20 may have needles at the locations where there are none in the rear needle bar, or the rear needle bar may have 2 needles adjacent to each other, then 2 needle spaces without needles, while the front needle bar has 2 vacant spaces and 2 needles at the locations where there are none in the rear needle bar, or even 3 needles in the rear needle bar and one vacant space, with three vacant spaces in the front needle bar and one needle at the location of the vacant space in the rear needle bar. All of these arrangements are complementary in the sense that total number of needles is no greater than the number of spaces between the sinkers 10. Of course, as another alternative, there may be fewer needles, with vacant spaces left in both bars at appropriate location.

Fabrics made on machines in which the needle bars 18 and 20 have

alternate needles

22 and 24 as shown in FIG. 3, offer new and interesting surfaces in which both wale and course lines are less prominent and provide a choice of either better stretch and recovery or greater stability. Thus, many new pattern possibilities are made available.

The two

needle bars

18 and 20 are mounted on

separate lifting arms

26 and 28, which are driven by separate crankshafts, cams, or eccentric devices in accordance with conventional practice, in such a manner so that they may be raised both alternately and together, in any sequence according to the pattern desired. The lifting mechanisms for the

arms

26 and 28 may, for example be activated by a pattern chain or pattern wheels, similar to the ones now used to control the lateral movement of the guide bars, as well as other functions. Such mechanisms provide a great variety in the sequence in which two needle bars may be raised and lowered. Separate yarn feed and tensioning mechanisms and separate knock over adjustments may also be employed so that both tight and loose stitches may be knitted side by side. New fabrics can be produced in accordance with this invention on either tricot or raschel machines, using beard or latch needles. Moreover, fabrics can be produced in accordance with this invention from very heavy denier yarns which cannot be knitted on a full set single needle bar machine. Such fabrics can be comparatively lightweight fabrics even though produced from relatively heavy denier yarn.

While this invention has been illustrated and described in a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.

Having thus disclosed the invention, What is claimed 1. A method of knitting novel fabrics on a knitting machine having a row of sinkers, rigidly mounted guide needles disposed above said sinkers, and a row of stitch needles below said sinkers and movable upwardly and downwardly relative to said sinkers, said method comprising, in any sequence a motion described by moving a first portion of the total number of said stitch needles in unison between said sinkers, forming a stitch on said stitch needles of said first portion without forming a stitch on the remainder of said stitch needles, and a motion described by moving a second portion of said stitch needles in unison between said sinkers, forming a stitch on said second portion of stitch needles without forming a stitch on said first portion stitch needles, and simultaneously moving said stitch needles of said first portion and said stitch needles of said second portion between said sinkers forming a stitch on said first and said second portion of stitch needles, said individual stitch needles employing a spacing sufficient to allow said rigidly mounted guide needles to clear when both said first portion and said second portion of stitch needles are simultaneously raised.

2. The method according to claim 1 wherein said first portion stitch needles and said second portion stitch needles are mounted on separate needle bars, and including moving said first needle bar between said sinkers while said second bar remains below said sinkers, moving said second needle bar between said sinkers, while said first needle bar remains below said sinkers, and simultaneously moving said first and said second needle bars between said sinkers, the movements being in any sequence.

3. A method of tuck stitch knitting novel fabrics on a knitting machine having a row of sinkers, rigidly mounted guide needles disposed above said sinkers, and a row of stitch needles below said sinkers and movable upwardly and downwardly relative to said sinkers, said method employing at least one motion comprising simultaneously moving a first portion of the total number of said stitch needles and a second portion of the total number of said stitch needles in unison between said sinkers, moving said first portion of the total number of said stitch needles down to the point of cast off while moving said portion of said stitch needles down but not to the point of cast off and then simultaneously raising said first portion stitch needles and said second portion stitch needles.

4. The process of claim 3 wherein said stitch needles are latch needles.

5. In a warp knitting machine having a row of sinkers, rigidly mounted guide needles associated with said sinkers, and a row of stitch needles associated with said sinkers, support means for said stitch needles comprising first and second needle bars on said machine, said needle bars being movable relative to each other and relative to said sinkers, said row of stitch needles being secured individually, either in said first bar or in second bar, said stitch needles being aligned with the spaces between adjacent sinkers and spaced such that when said first and said second needle bars are simultaneously in a raised position said rigidly mounted guide needles may pass between said stitch needles, said first needle bar and said second needle bar being driven by an eccentric device in a manner such that said first needle bar and said second needle bar are raised both alternately and simultaneously in any sequence.

6. A warp knitting machine according to claim 5 wherein said first and second bars have a plurality of needle locations, said locating being substantially equally spaced along said bars, said needles being positioned at locations, but the number of locations in one bar being greater than the number of needles in said one bar.

7. A warp knitting machine according to claim 6 wherein the total number of needles in both needle bars is no greater than the total number of spaces between said sinker bar.

8. A warp knitting machine according to claim 7 wherein said needle locations in both said first and second bars are aligned with each of said spaces between said adjacent sinkers, each space between said adjacent sinkers having less than two needles, whereby needles are selectively mounted in one needle bar or the other, or are omitted from both bars for each of said sinker spaces.

9. A warp knitting machine according to claim 8 wherein said guide needles are movable in unison at each of said sinker spaces, whereby the presence or absence of the stitch needles affects the pattern of stitch- 10. A warp knitting machine according to claim 8 wherein said stitch needles are movable longitudinally into said space between said sinkers.

Claims

1. A method of knitting novel fabrics on a knitting machine having a row of sinkers, rigidly mounted guide needles disposed above said sinkers, and a row of stitch needles below said sinkers and movable upwardly and downwardly relative to said sinkers, said method comprising, in any sequence a motion described by moving a first portion of the total number of said stitch needles in unison between said sinkers, forming a stitch on said stitch needles of said first portion without forming a stitch on the remainder of said stitch needles, and a motion described by moving a second portion of said stitch needles in unison between said sinkers, forming a stitch on said second portion of stitch needles without forming a stitch on said first portion stitch needles, and simultaneously moving said stitch needles of said first portion and said stitch needles of said second portion between said sinkers forming a stitch on said first and said second portion of stitch needles, said individual stitch needles employing a spacing sufficient to allow said rigidly mounted guide needles to clear when both said first portion and said second portion of stitch needles are simultaneously raised.

4. The process of claim 3 wherein said stitch needles are latch needles.

9. A warp knitting machine according to claim 8 wherein said guide needles are movable in unison at each of said sinker spaces, whereby the presence or absence of the stitch needles affects the pattern of stitching.

10. A warp knitting machine according to claim 8 wherein said stitch needles are movable longitudinally into said space between said sinkers.