US2737913A - Needle construction - Google Patents

Description

March 13, 1956 R. c. KLINE NEEDLE CONSTRUCTION Filed Sept 1953 INV TOR. RICHARD C. KLNE ACIT RNE-Y United States Patent- O 2,737,913 NEEDLE CONSTRUGHON Richard C. Kline, Mount Kisco, N. Y. Application September 2, 1953, Serial No. 378,640

3 Claims. (Cl. 112-79) The present invention relates generally to tufting devices for the manufacture of carpet and the like, and in particular to an improved needle assembly for forming stitches or loops of yarn on a fabric base in the production of loop-pile or cut-pile carpets.

In the manufacture of tufted carpets, especially those of varying sizes, shapes and designs, it is often expedient to employ a manually manipulated hooking device, which is either mechanically or hand driven, and is effective to tuft carpet yarns into a foundation fabric, usually of woven and intermeshed threads. A hooking device well suited for this purpose may include longitudinally slidable thrust members movable relative to each other, one of the thrust members carrying one or more laterally aligned needles, and the other of the thrust members carrying a corresponding number of stepper prongs. Upon imparting steering motion to the needles and stepper prongs in appropriate timed relation, the needles are first passed through the foundation fabric carrying along the tufting yarn, whereupon the steppers are advanced through the foundation fabric into side-by-side positions in relation to the needles to constrain the tufted yarn as a partially formed loop or stitch. Upon withdrawal of the needles to complete the loops and preparatory to succeding tufting stitches, the stepper prongs remain stationary and hold the partially formed loops. Thereafter, the cyclic and timed displacement of the needles and stepper prongs repeats to form further loops or stitches.

As the needles pierce the interwoven fabric base during formation of successive loops, the warp and weft threads of the fabric base are spread apart and distended to permit extension therebetween of the needles with attendant tensioning of the fabric threads. Upon withdrawal of the needles followed by the stepper prongs incident to completion of successive stitches or loops, the warp and weft threads, if not overstressed, are partially restored to their initial woven pattern, remaining somewhat under tension by the presence of the interposed yarn loops. In most instances, this tensioning is relied upon to maintain successive stitches as formed, especially when further processing is needed.

A frequently encountered problem has been the tendency of the yarn of a previously formed loop to feed into the following loop while the latter is being hooked. This difficulty becomes more marked when manufacturing cutpile carpet, since this requires cutting of successively formed loops concurrent with or following hooking. As a general proposition, insufficient tension exerted by the foundation fabric on the yarn of the formed loopepile or cut-pile carpet runs the risk of uneven pile height over a piece of goods and/ or pulling out of loops, both necessitating extensive revisionof the gopds,

Steps have been taken to overcome the mentioned culties, characterized by looseness of the loops formed on the base fabric, by careful selection of the types of material for the base, control over the tightness gt the we ve. t e pp ic ion of '01; t9 the ns, an the gene a p ev 2,737,913 Batented Mar. 13, 1956 2. assemblies. However, these various precautions and mechanisms usually entail increased cost and the need for continuous supervision by skilled personnel.

It is therefore'an object of the present invention to provide a tufting device obviating one or more of the aforesaid shortcomings, preferably in a manner compatible with manufacture at relatively low unit cost. Specir'ically, it is within the contemplation of the present invention to provide a needle assembly which substantially accommodates associated stepper prongs and the like, as well as the yarn being tufted, thereby minimizing overstressing of warp and weft threads of the base fabric and the manifest disadvantages.

Certain objects of the present invention are realized by the provision of a reciprocatory tufting needle including an elongated slot terminating in an end wall associated with a tensioning prong nested with the needle and including an end face adjacent to and spaced from the end Wall of the slot. The end face of the tensioning prong cooperates with the adjacent wall of the slot to provide an aperture through which the yarn may be threaded. The tensioning prong is further arranged relative to the needle to define a longitudinal yarn-accommodating channelway which opens into the yarn-receiving aperture, whereby the yarn may be accommodated substantially within the cross section of the needle during feed toward the yarn-receiving aperture. The length of the elongated slot is related to the throw or stroke of the needle to permit retention of the yarn within the channelway during forma tion of successive loops thereby decreasing the effective cross-section of the yarn-inserting assembly during formation of successive loops or stitches.

The above objects and brief description, as well as further features and advantages of the present invention will become apparent upon reference to the following detailed description of a presently preferred embodiment, when taken in conjunction with the accompanying drawings, wherein:

Fig. l is a sectional view, with parts broken away, showing a carpet-forming device embodying features of the present invention, illustrated in the position wherein a loop is formed, but prior to restrain by the stepper prong;

Fig. 2 is a sectional view, similar to 'Fig. l, but showing the cycle advanced to the time at which the stepper prong is arranged in side-by-side relation relative to the needle to constrain the formed loop preliminary to withdrawal of the needle;

Fig. 3 is a sectional view similar to Fig. 2, but showing the cycle progressed to the time at which the needle is withdrawn from the fabric base and with the stepper prong retaining the formed loop; and,

Fig. 4 isan elevational View taken from the right of Fig. 1.

Although the invention is illustrated specifically in conjunction with a hand-operated device for forming looppile carpet, it is to be expressly understood that the described needle assembly may be mechanized, for example as disclosed in U. S. Patent 2,680,993 of June 17, 1953. Further, it is within the contemplation of the invention to employ the needle assembly in the formation of cutpile carpeting in accordance with weil understood principles. In the following description, the term elastic limit as applied to the warp and weft threads of the interwoven fabric base, is to be construed as meaning the maximum tension which may be placed on these threads incident to the piercing of the needle assembly into the fabric foundation, such that upon withdrawal of the needle assembly, the unfilled hole in the fabric foundation will be smaller than the cross-section of the yarn scheduled to be accommodated therein. tated differ: onl when the m il is era d a con m late he h ead mus restat ssfiis ent t9 sq stt t n-std yarn loops by the tensioning effect exerted by the warp and weft threads. The term effective stroke length as applied to the needle is to be construed as meaning the distance between the yarn-receiving aperture of the needle and the maximum depth of needle penetration. In most instances, this will correspond to the pile height or depth.

Referring now specifically to the drawings, there is shown a needle-thrust member or bar ltl and a stepper thrust member or bar 12, interconnected for longitudinal displacement relative to each other in spaced and parallel paths. Projecting from the lower end of the needle thrust member 10, which is arcuately curved at Lida to provide a lateral shoe or yarn guide surface, is a needle assembly including laterally contiguous and aligned needles i4, i6 and 18. The respective needles are assembled to the needle thrust bar 10 by appropriate screws or like, and if needed, additional rigidity may be imparted to assembly by soldering together the contiguous longitu dinal edges of the needles in the regions designated by the numeral 22 as seen in Fig. 4. Since each of the needles is of similar construction, it will sullice for the present purposes to describe only one in detail. For example, the needle 14 is a sheet metal stamping of tempered steel or the equivalent, which includes a base section 14a secured in abutment with the thrust bar it), an intermediate section 14b projecting beyond the shoe or surface ltla of the thrust bar 10, and a piercing section Me which terminates in a point 14d. Although the needle 14 is generally planar and of flat sheet material, marginal portions are reinforced and stiffened as by marginal flanges 14c, 14 extending at right angles to the needle proper and generally co-extensive with the lateral side edges of the base and intermediate sections 14a, 14b. Formed longitudinally of the intermediate section 14:) of the needle 14, is an elongated slot 24 bounded by opposed longitudinal marginal edges or walls 2 in and leading and trailing lateral marginal edges or walls 24b. The several purposes of the elongated slot 24- in each of the needles will become apparent upon further description of the device. As clearly seen in Fig. 4, the length of the slot 24 is at least three times the slot width as measured by the separation between the longitudinally extending walls 24a.

In order to impart appropriate tension to yarn Y which is to be fed to the respective needles through appropriate eyelets 26 on the needle thrust member 10, yarn-tensioning prongs or members 28, 3th and 32 are associated with the respective needles. By reference to Figs. 1 to 3 inclusive, it can be seen that the yarn-tensioning prongs, for example, the prong 28 associated With the needle 14 is accommodated or nested within the outline of the needle 14 and is disposed in a plane generally offset from and at one side of the plane of the needle. Further the yarn tensioning prong 28 is bowed toward the needle 14 to provide an end or contact face 28a disposed in spaced relation adjacent to and in substantially coplanar relation with the leading lateral end wall 24a of the slot 24. The leading terminal wall 24a of the slot 24 and the leading contact end or face 28a of the tensioning prong 28 are concavely curved and cooperate to define a substantially circular yarn-receiving aperture of a cross-section, related to the section of the yarn. Although the several tensioning prongs are shown rigidly fixed to the needle thrust bar by screws 34, it is to be expressly understood that the yarn-tensioning prongs may be adjusted relative to their associated needle, so that the generally circular aperture may be adjusted to obtain an effective opening commensurate with the cross-section of the yarn.

As a prominent feature of the present invention, the longitudinal edges or walls 24:: of the slot 24 and the laterally offset tension prong cooperate to define a longitudinally extending yarn-accommodating channelway 36, which merges into the yarn-receiving aperture defined by the concave faces 24a, 28a. As can be seen by viewing Figs. 1 and 2, the leading leg 11 of the loop or stitch L being formed may be accommodated entirely within the channelway 36 during piercing of the base B by the needle 14, while the trailing leg 12 can be accommodated substantially within the outline of the needle and rearwardly of the associated tensioning prong.

in order to constrain a partially formed loop L during hooking of the next successive loop, stepper prongs, all indicated by the numeral 40, are associated with the respective piercing needle and tensioning prong assemblies.

Although not shown in detail, the stepper prongs 40 are fixed to the stepper thrust member or bar 12 and take the form of a stamping from spring steel or the equivalent having a series of three prongs which are laterally spaced according to the needle spacing, the prongs being bent in the direction of the needles and having concave free ends 40:: engaging the yarn during the tufting cycle as detailed below.

As can be appreciated by reference to Fig. l, the pile height is determined by the needle stroke, which in turn is controlled at least in part by the spacing of the leading end wall 24b of the slot 2 relative to the shoe 10a. By making the length of the channelway 36 in excess of the needle stroke required to form the loop L, the leading leg [1 of the loop L will be substantially accommodated within the outline of the needle and laterally confined by the opposed longitudinal walls 24a of the slot 24. If not for the channelway 36, the leading leg 11 of the loop L would lie against the outer surface of the needle, with no provision for lateral constraint and requiring a corresponding enlarged piercing hole for the extension of the yarn through the backing cloth B. This would result in unneeded tensioning of the warp and weft threads b1, b2 of the base B. Even though the yarn is nested and laterally constrained by the needle, it is to be observed that the tensioning prong 22 is completely effective to maintain the yarn in desired loop lengths. Thus by the arrangement of the needle and the transioning prong, forming both the channelway 30 and the yarn feeding aperture, the warp and Weft threads b1, [22 of the fabric base B are not as greatly stressed. This reduces the risk of exceeding the desired elastic limit and as sures return of the warp and Weft threads to a gripping position relative to the yarn loops.

A typical cycle of operation will be described as applied to the formation of successive uncut loops L on the fabric base B:

Referring now to Fig. l, the needle thrust bar 10 is shown with the shoe 10a bearing against the base fabric B, the needles 14, 16, 18 having been pierced through the base fabric and carrying therewith an appropriate length of yarn Y to form the loop L. Thereupon the steeper thrust bar 12, which is reciprocated in lagging and timed relation to the needle thrust bar by mechanical means or hand operation, is advanced (as seen in Fig. 2) to bring the respective stepper prongs into position for maintaining the formed loops L. Thereupon, the needles l4, 16, 18 are withdrawn (as seen in Fig. 3) with the yarn-retaining prongs or steppers 40 in the extended position and holding down the formed loops. The needles are again advanced, piercing the base fabric at a location ahead of the formed loops L, whereupon the steppers may be retracted, and through spring action, are restored to the operative position immediately contiguous to the extended needles for constraining the next set of loops.

From the foregoing, it can be appreciated that the needle assembly of the present invention, whether employed in the formation of loopor cut-pile carpeting and/or whether mechanically or hand operated, is effective to form successive loops on a woven fabric base without excessively distorting the warp and weft threads of the base, thereby contributing substantially to firm gripping of the loops by the base fabric.

While in accordance with the provisions of the statues, I have illustarted and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the article disclosed without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What I claim is:

l. A tufting assembly including a longitudinally-reciprocable needle having a wall formed with an elongated slot laterally bounded by opposed longitudinally-extending walls and terminating in a forward transversely-extending wall, a yarn-tensioning prong nested within and movable with said needle and having a contact face adjacent to and spaced from said transversely-extending wall and cooperating therewith to form a yarn-receiving aperture, said yarn-tensioning prong being generally offset from said wall and cooperating with said opposed longitudinally-extending walls of said elongated slot to form a yarn-accommodating channelway within the confines of said needle and merging into said yarn-receiving aperture, and a longitudinally-reciprocable stepper prong displaceable relative to the assembly of said needle and yarntensioning prong and adapted to cooperate therewith in forming successive yarn loops on a fabric base.

2. A tufting assembly including a longitudinally-re ciprocable needle having a wall formed with an elongated slot laterally bounded by opposed longitudinally-extending Walls and terminating in a forward transversely-extending wall, said slot being of a length in excess of three times its width, a yarn-tensioning prong nested within and movable with said needle and having a contact face adjacent to and spaced from said transversely-extending wall and cooperating therewith to form a yarn-receiving aperture, said yarn-tensioning prong being generally offn set from said wall and cooperating with said opposed longitudinally-extending walls of said elongated slot to form a yam-accommodating channelway within the conlines of said needle and merging into said yarn-receiving aperture, and a longitudinaliy-reciprocable stepper prong displaceable relative to the assembly of said needle and yarn-tensioning prong and adapted to cooperate therewith in forming successive yarn loops on a fabric base.

3. A tufting assembly including a longitudinally-reciprocable needle having a wall formed with an elongated slot laterally bounded by opposed longitudinally-extending walls and terminating in a forward transversely extending wall, said slot being of a length in excess of three times its width, a yarn-tensioning prong nested within and movable with said needle and having a contact face adjacent to and spaced from said transversely-extending wall and cooperating therewith to form a yarn-receiving aperture, said yarn-tensioning prong being generally 0&- set from said wall and cooperating with said opposed longitudinally-extending walls of said elongated slot to form a yam-accommodating channelway within the conlines of said needle and merging into said aperture, and a longitudinally-reciprocable stepper prong displaceable relative to the assembly of said needle and yarn-tensioning prong and adapted to cooperate therewith in forming successive yarn loops on a fabric base, said transverselyextending wall and said contact face each being curved concavely whereby said yarn-receiving aperture is substantially circular.

References Cited in the file of this patent UNITED STATES PATENTS 604,759 Johnson May 31, 1898 l.487,318 DeForest Mar. 18, 1924 1,832,636 Kalbach Nov. 17, 1931 2,591,944 Kline Apr. 8, 1952 2,600,993 Kline et a1. June 17, 1952 2,635,567 Drake Apr. 21, 1953

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