Synchronous Grass Tufting Machine

This invention claims the benefit of U.S. Provisional Patent Application No. 63/659,394 filed Jun. 13, 2024, which is incorporated herein by reference in its entirety.

This invention relates to tufting machines, particularly those for manufacturing artificial grass products, and in still more particular, sports field applications with multiple colors.

When manufacturing artificial grass tufted fields, many manufacturers tuft a single colored field (aka, normally green) and then design areas or field markings are often separately tufted. Installers, if not manufacturers, then often cut and paste the field markings, and/or logos or other designs relative to the background to attempt to maintain the integrity of the field while providing what is normally a lower resolution or simple image. This time-consuming and difficult process has led to attempts such as U.S. Pat. No. 9,051,672 to provide staggered needle bars where each needle bar tufts a single color of yarn and leave areas untufted where another color is to be tufted. The asynchronous needle bars and associated loopers/hooks are spaced many feet apart thereby requiring significant space for a manufacturing company that desires to have an ability to tuft multi-colored logos or have multi-colored field lines for various sporting activities.

Conventional broadloom tufting machines designed for manufacturing carpet and artificial athletic turf in high volume are primarily characterized by having cooperating backing feed and tufting head assemblies. Typically, such a backing feed assembly is defined by al arrangement of feed and take-up rollers that convey an elongate sheet of backing fabric through a tufting zone area in which yarn is inserted into the steppedly advancing backing. Differential rotation between feed assembly rollers stationed at opposing ends of the tufting zone creates longitudinal tension in the backing.

The tufting head portion of the broadloom machine generally features one or more elongate bars of yarn-delivering needles which are disposed above the horizontal backing and aligned transverse to the direction of its movement, as well as an equivalent number of yarn-catching loopers that are disposed below the backing. Needles along the needle bar(s) each receive yarn, delivered by any of a variety of suitable yarn feed mechanisms, from a designated spool situated within a yarn creel. So, as the backing sheet travels past the tufting head, needle bars are continually reciprocated downward so that the needles along them penetrate and insert yarn into the backing in unison. The loopers operate in synchronicity with the needles such that, as each needle momentarily protrudes the backing, a corresponding looper catches its yarn before the needle returns upward. This repeated interaction produces “loop pile” tufts of yarn along the backing. Additionally, knives can be used to sever just-formed loops and thereby render “cut pile” tufts.

Where uniformly patterned carpet or vast monochrome sections of athletic turf are to be produced in high volume, a broadloom tufting machine's needles can span the entire transverse width of the backing material. The incremental, longitudinal progression of the backing material that immediately follows each stroke of the needle bar causes the laterally-aligned needles to form every longitudinal running row of tufts intended to be created across the lateral length of the backing sheet. Thus, the tufting needles stationed along the needle bar remain at constant lateral positions, and there is no need for them to be transversely shifted when creating carpet or turf sections having uniform tuft placement and yarn color. On the other hand, tufting machines exhibiting constant axis needle bar movement are generally not suitable for producing multicolored articles of tufted material. So, the prior art has seen tufting machines improved to enable their needle bars to shift laterally, relative to the backing, in order that the particular type of yarn delivered by particular individual needles be selectively inserted into the backing at specific tuft locations in accordance with a preconceived pattern. For example, U.S. Pat. No. 4,829,917 to Morgante, et al. discloses the use of a computer-controlled hydraulic actuator for shifting a needle bar into different lateral positions in response to pre-selected stitch pattern information stored in the computer. As another example, U.S. Pat. No. 5,979,344 to Christman. Jr. discloses the use of computer-controlled inverse roller screw actuators for shifting needle bars laterally, as well as for shifting the backing sheet itself laterally, in order to tuft a graphic pattern of yarn into the backing as it advances longitudinally past transversely aligned needles. The applicant's V-tech technology as described in U.S. Pat. No. 10,889,931 is certainly another way to shift the backing sheet relative to needles.

Nevertheless, even with the lateral shiftability of needles relative to backing, backing relative to needles, or both, these prior tufting machines that employ backing feed mechanisms have not successfully been employed to producing precise, dynamic, multicolored tuft patterns like those often found in artistic logo-bearing sections of artificial athletic turf.

Inherent characteristics of backing material itself tends to undermine the quality of graphic output of these prior art machines. To wit, because backing sheets are typically fabricated of coarsely woven material, they are susceptible to being non-uniformly stretched, in either direction, as feed rollers advance them through the tufting zone. Since athletic field logos, and certainly field lines, are almost always too large to be entirely formed within the lateral boundaries of a machine's tufting zone—which is typically no more than 15 feet wide they must be created in pieces by individually tufting separate sheets of backing material and then gluing those sheets, side-by-side, onto a base layer material. This leaves open the possibility that one image-bearing section of backing will progress through the tufting zone differently, in some respect, than does an adjacently laid section and will, in turn, manifest as color discontinuity within the composite image that is visible upon installation. Therefore, in the process of tufting separate graphically patterned artificial turf pieces for a single installation, there is a premium on being able to ensure that tension applied to backing material remains consistent and that no unwanted lateral movement occurs within the tufting zone.

Tufting head assemblies that operate while moving two-directionally relative to statically held backing sheets have been developed in the prior art to address these stability concerns related to production of detailed tuft patterns. See, U.S. Pat. Nos. 5,743,200 and 7,814,850. This technology is believed to significantly slow the speed of manufacturing.

Accordingly, the present invention a longstanding need for a tufting machine configured to produce continuous, lengthy sections of graphic and non-graphic athletic turf under conditions of backing stability achieved by previous fixed backing machines, at a satisfactory throughput rate. U.S. Pat. No. 9,051,672 advertises that it achieves this longstanding need. A simpler, more compact system which operates differently of a tufting machine of the present invention is believed to substantially fulfill this need.

Instead of having asynchronous tufting of separated tufting heads with needle bars having corresponding hooks and knives as is done in U.S. Pat. No. 9,051,672, the applicant has developed selectively synchronously deployed needle bars driven by a common driver or geared to the same drive. When using Independently Controlled Needles (ICN) machines, such as those having adjacent needles of two different colors in a needle bar in one or both of first and second rows of needles, four different colors may be selectively tufted at a specific location. Since all yarns are cut when transitioning from one color to another, for at least some embodiments, there will be a void when starting the next color, whether on a front or back row since there will be no instruction to insert the former color at the void. ICN Machines are described in Kaju, U.S. Pat. No. 5,392,723, incorporated herein by reference. Some embodiments may provide cut loop, loop or combinations thereof for various embodiments.

The applicant has been able to space the front needle bar at up to 20 inches in front of a rear needle bar, preferably in a mechanically linked manner, while still having sufficient room to access and operate loopers/hooks and knives below the backing. This construction is different than applicant's prior at U.S. Pat. No. 4,841,886, incorporated herein by reference. Depending on the specific ICN machine selected, a specific needle in the front row is either selected to be driven through the backing, or not. The same is true for the rear row of needles. Since there is spacing between the rows of needles, it is further possible that needles in both the front and rear rows at the same position are selected at the same time (but they do not drive yarn through the same hole since there is a 9-12 inch spacing in the direction of backing feed.

The applicant has achieved the desired tufting in two different ways. Needles of the first and second needle rows may be moved into and out of the backing (selectively) with a synchronized driver (such as the driven shaft having a gear to drive a geared slave shaft with one rotating clockwise and the other rotating counterclockwise, or otherwise, with other gearing/coupling relationships, or otherwise), or a bridge driver (a single push rod drives a bridge oriented in the direction of backing feed with the front and rear needle rows oppositely disposed relative to the push rod). While bridge drivers having a common push rod have been employed laterally or perpendicularly to the direction of feed, the applicant is unaware of any use of a bridge driver to drive needles into and out of backing in the direction of feed. For synchronized driving with the front and rear needle bars linked or geared together in synchronization, counterweights on one or both shafts driving the vertical reciprocation may be desirable.

Backing may also be shifted to select gauge. See U.S. Pat. No. 11,661,694, incorporated herein by reference. Both backing and/or needle bars such as provided in U.S. Pat. No. 4,285,787, incorporated herein by reference, may be moved in still further embodiments.

In a four color machine, the applicant has provided A/B setup on the front needle bar and C/D setup on the rear needle bar to provide for one of four possible color choices at each location along the backing. Still other embodiments may provide more than six color choices such as by providing A/B/C on the front needle bar and D/E/F on the rear bar and shifting at least two positions on each lateral indexing of the backing. Also, the front and rear needle bars need not necessarily provide the same number of color choices. The front could provide A, the rear could provide B/C, etc. Hall. U.S. Pat. No. 8,141,505, incorporated herein by reference, discloses A/B/C/D threading on four different yarns. A/B patterns, or A/B/C patterns, or other patterns may be selected as would be understood by those of ordinary skill in the art.

More sophisticated pattern attachments and associated systems like applicant's iTuft™ (see U.S. Pat. No. 11,661,694 incorporated herein by reference) may provide extremely precise yarn control and possibly provide pattern loop, pattern cut or pattern cut and loop constructions. Dense or more loosely tufted options are possible. Needle clamps may be employed to prevent certain needles from performing certain stitches in at least some embodiments. Knife wedges may also be employed to separate knives from hooks when no yarn is being tufted or particular hooks. Some embodiments may not require sophisticated yarn feed systems depending on the particular desired uses. For instance, shag carpet may not require additional “boost” of yarn pull provided by needle clamps or sophisticated pattern attachments.

The backing is preferably indexed incrementally with a cloth feed past the needle bars. Forward movement of the backing is preferably halted while shifting at least one of the backing and needle bar to ensure desired placement of a particular color at a specific location on the backing.

A common bed plate and pin rollers may be provided with many embodiments. By synchronizing the tufting of the front and rear tufting heads, precise and rapid tufting may occur. With ICN and each tuft being cut, precise locations of each tuft is achieved so that each location may be addressed with one of the various colors since each tuft location will be selectively penetratable by a needle of every color provided to the tufting machine for at least many embodiments.

Turning then to, a generalized tufting machineand a creelto hold cones or spools of yarn is illustrated. It should be understood that aspects of the invention can be practiced on a wide variety of tufting machines, not simply the broadloom machinedepicted in. Indeed, versions of the system can be implemented on most computer controlled tufting apparatus and sensor data can be captured and processed in an even wider variety of settings.

For explanatory purposes, the tufting machinedisclosed inincludes a rotary needle shaft or main drive shaftdriven by stitch drive mechanismfrom a drive motor or other conventional means, rotary eccentric mechanismmounted upon rotary needle shaftis adapted to reciprocally move the vertical push rodand possibly first push rodfor vertically and reciprocally moving the first needle bar slide holderand first needle bar. The first needle barsupports a plurality of uniformly spaced tufting needlesin a longitudinal row or staggered longitudinal rows, extending transversely of the feeding direction of the backing fabric or material. The backing fabricis moved longitudinally in directionthrough the tufting machineby the backing fabric feed mechanismand across the backing fabric support with needle plate and needle plate fingers.

Second push rodvertically and reciprocally moving the second needle bar slide holderand second needle bar. The second needle barsupports a plurality of uniformly spaced tufting needlesin a longitudinal row or staggered longitudinal rows, extending transversely of the feeding direction of the backing fabric or material. Second needle baris preferably synchronously tied to first needle bar to be moved vertically and reciprocally with first needle barsuch as being connected with bridge(s)or gearing(shown in phantom in). First and second may be front and rear, or visa versa, depending upon design characteristics as would be understood by those of ordinary skill in the art.

Yarnsare fed from the creelto the pattern control yarn feedto the respective needles. When any individual needlecarries a yarnthrough the backing fabric, a first hook or first looperis reciprocally driven by looper driveto cross each corresponding needleand hold the corresponding yarn endto form loops. Cut pile tufts are preferably formed by cutting the loops with knives. Each component, the looper drive, the yarn feed, needle selector, needle bar or backing shifter, and backing feed apparatus, may share and/or have independent controllers such as the operator controls.

Yarn feedmay be simple or complex, like U.S. Pat. No. 11,661,094 or other yarn feed system.

The same, or different system can feed the yarnsto needles. Second hook or second looperis reciprocally driven by looper driveto cross each corresponding needleand hold the corresponding yarn endto form loops. Cut pile tufts are preferably formed by cutting the loops with knives. Each component, the looper drive, the yarn feed, needle selector, needle bar or backing shifter, and backing feed apparatus, may share and/or have independent controllers such as the operator controls. Some embodiments may cut all loops, some embodiments may provide both cut and uncut loops, and some embodiments may not cut any loops.

The needle bar shifteris designed to laterally or transversely shift needle bars,relative to the needle bar holders,a predetermined transverse distance, typically equal to the needle gauge or multiple of the needle gauge, and in either transverse direction from its normal central position, relative to the backing fabric, and for each stroke of the needles,. The rows of needles,can preferably be shifted in unison or independently.

A jute or backing shiftermay move the backing fabric laterally with respect to a transversely stationary needle bar, or simultaneously with one or more transversely shifting needle bars. If backing shifteris utilized, an oscillating needle plate, such as described in U.S. Pat. No. 11,802,359, incorporated herein by reference, may also be utilized and moved with needle plate shifteras seen in.

Whether any needle,passes through backing on any given stroke is dependent upon the pattern and whether that particular needle,is selected by the needle selector mechanism. Needle clampsmay be useful to hold specific selected needles,from engaging the backing in a stroke. Knife wedgesmay be useful to keep the knives from cutting yarn against hooks when no yarn is being tufted on particular hooks.

In order to generate input encoder signals for the needle bar shifting apparatuscorresponding to each stroke of the needles, an encodermay be mounted upon a stub shaft, or in another suitable location, and communicate positional information from which a tufting machine controller can determine the position of the needles in the tufting cycle. Alternatively, drive motors may use commutators to indicate the motor positions from which the positions of the associated driven components may be extrapolated by the controller. Operator controlsmay also interface with the tufting machine controllersto provide necessary pattern information to the storage associated with the various tufting machine controllersbefore machine operation.

Needle selector mechanismpreferably assists in selecting which, if any of needles,on the needle bars,are selected to penetrate the backing fabricon any specific stitch (downstroke of any pushrod,). No other party is believed to have provided synchronously driven needle bars,with ICN capability. No other party is believed to have provided bridgesfrom a common push rodoriented with the bridgesparallel a direction of feedand/or provide spaced apart needle bars,with independent control of any needle,on the needle bars,. No other party is believed to have provided selectively synchronizable needle bars spaced apart in the direction of feed with corresponding selectively synchronizable loopers with front and rear needles independently selectably controlled to provide stitches separately from each other or in unison.

While bridgesfunction particularly well for many embodiments to join a front and rear pushrod,to main shaftvia vertical push rod, other embodiments may rely more on gearing or linkages to couple a first shaftto a second, or slave, shaftsuch as with gearingor otherwise as shown in. First shaftcould correspond to the main shaftin many embodiments. Counterweights,may be helpful for many embodiments.

While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alterations, modifications, and variations in the appended claims.