MODULAR LOOPER APPARATUS FOR NARROW GAUGE TUFTING MACHINE

Abstract: A modular looper apparatus (18) for a narrow gauge, multiple-needle tufting machine including modular hook bars (20) made of solid material with hook slots (35) formed in the upper portion of each hook bar (20). Looper hooks (36, 36') are retained in the hook slots (35) by an elongated cap plate (50) secured transversely along the top portions of the hook bars (20), and the hook bars (20) are firmly seated in an elongated transverse recess (47) in a transverse back-up bar (21) to which the hook bar (20) is secured by threaded bolts (54). Set screws (55, 56) are threadedly extended through the front solid portions of each hook bar (20) for engaging the individual looper hooks (36, 36'). The individual looper hooks (36, 36'), as well as each modular hook bar (20), are designed for simple and rapid removal, insertion and replacement. The stabilility and rigidity of the solid looper apparatus (18) construction results in superior resistance to the pressures exerted by the cutting knives (58) against the sides of the looper hooks (36, 36') in a cut pile tufting machine.

Description: MODULAR LOOPER APPARATUS FOR NARROW GAUGE TUFTING MACHINE Technical Field This invention relates to a multiple-needle tufting machine, and more particularly to a modular looper apparatus for a multiple-needle tufting machine. Background Art The conventional hook bars for multiple-needle tufting machines are long bars extending transversely of the machine below the needles and the base fabric. A conventional cut-pile hook bar has uniformly spaced slots in its front face for receiving the hooks which cooperate with the needles to form loops in the yarns carried by the needles. For a narrow gauge, multiple-needle tufting machine, the slots in the front face of the hook bar must be formed close together. The closeness of the spacing of the looper slots is limited by the thinness of the walls between the slots. Conventional loopers or hooks are held in their respective slots by individual set screws which are threaded into each slot and engage the opposed walls or lands of the slots. Thus, the thin¬ ness of the walls is further limited by the diameters of the set screws. Moreover, the threaded movement of the set screws tends to expand and warp the slot walls or lands. One solution to spacing the looper slots closer together in a narrow gauge tufting machine is dis- closed in the prior U.S. Patent No. 3,635,177, issued to Larry P. Gable, et al for NARROW GAUGE HOOK BAR FOR TUFTING MACHINE on Jan. 18, 1972. The Gable patent discloses a hook bar having uniformly spaced, but staggered, looper slots formed alternately in the front and rear faces of the hook bar. Thus, the staggered front and rear slots receive two transverse rows of staggered hooks or loopers for cooperation with corresponding staggered needles. However, the hook bar disclosed in the Gable patent was primarily designed for a looper apparatus for forming narrow gauge loop pile. Another method of spacing the hook slots closer together in a narrow gauge tufting machine is dis- closed in U.S. Pat. No. 4,067,270 of Hoyt E. Short for "NARROW GAUGE CUT PILE TUFTING APPARATUS," in which the needles are staggered and the loopers are made quite thin and flexible for bending and veering around each of the corresponding staggered needles. A further solution for spacing loopers and hook slots closer together in a narrow gauge machine is disclosed in U.S. Pat. No. 4,158,339 of Hoyt E. Short, issued June 19, 1979, for "NARROW GAUGE CUT PILE LOOPER APPARATUS." In this narrow gauge cut-pile tufting machine, the needles are staggered and the slots are formed in the front and rear faces of the hook bar. However, the slots are designed to extend along the top of the hook bar and to receive and reinforce the elongated body portions of the specially constructed looper hooks. Another type of hook bar or looper apparatus for mounting a plurality. of looper hooks close to¬ gether in order to provide a more narrow gauge for cultiple-needle tufting machine, is disclosed in U.S. Pat. No. 4,217,837 of Max ϊi. Beasley, et al, issued August 19, 1980, for "FINE GAUGE LOOPER APPARATU FOR IN-LINE TUFTING MACHINE." In this looper apparatu the hook slots are formed in an insert bar received in the front face of the hook bar, and the looper hooks are held in position by a plurality of clamp □embers threadedly secured to the hook block and against the front body portions of the looper hooks. The hook bars are made in the form of elongated nodules which are mounted end-to-end and each of the clamp members is adapted to secure a limited number of hooks upon the hook bar nodule. In recent times, a plurality of thin hooks have been mounted securely and precisely in a hook bar by casting the metal forming the hook bar around the * " OM pre-set hooks. However, although strength, rigidity, and precision are attained, nevertheless an entire cast module of hooks must be discarded if only a single hook becomes defective. Disclosure of the Invention It is therefore an object of this invention to provide in a multiple needle tufting machine, parti¬ cularly adapted for cut-pile tufting, an improved looper apparatus having a solid, stable hook bar with individual shallow hook slots independently receiving corresponding looper hooks, with special means for mounting the hook bars for reciprocal move¬ ment and for securing the hooks within the hook bar. The looper apparatus made in accordance with th invention is adapted for utilization in staggered needle cut pile tufting machines or in-line (single needle row) tufting machines having coarse gauges or narrow gauges in the order of 1/lOth of an inch or greater. More specifically, the looper apparatus made in accordance with this invention includes a plurality of elongated hook bars made of solid material, speci¬ fically steel, in which elongated, transversely spaced, shallow hook slots are formed in the top portion of the hook bar and the slots are open upwardl and forwardly in the hook bar. Special looper hooks have body portions with rearward projecting shank portions, each shank portion being adapted to be snugly seated within its corresponding hook slot in the hook bar, in operative position, with the throats and bills of the hooks projecting forward from the front face of the hook bar. A transverse top wall formed in the front portion of the hook bar projects above the remaining top portion of the hook bar behind the top wall to provide an elongated transverse groove or depressed area for receiving a cap plate on top of the hook bar to hold the shank portions securely within their respective slots. A plurality of set screws project, preferably at an angle, rearwar OMPI and upward from the front face of the hook bar to individually engage the bottom edges of the shank portions of corresponding looper hooks. A plurality of the modular hook bars with their hooks and cap plates are firmly seated in a front- facing transverse recess in an elongated back-up bar. Preferably, the rear edge of the cap plate of each modular hook bar also projects into the recess in the back-up bar snugly above the hook bar where the hook bar and the cap plate are firmly held against movement. The set screws are threaded through solid portions of the hook bar beneath these slots until the free ends of the set screws penetrate the slots for firm engagement with the bottom edges of the respective shank portions of the looper hooks. The modular hook bars are securely held in the transverse face recess of the back-up bar by trans¬ versely spaced threaded bolts, rather than by welding. In a preferred form of the invention, the body <* portion of each looper hook has a rearwardly facing, vertical rear shoulder for snug engagement against the front edge portion of the transverse cap plate for further stabilized support of the looper hooks. Moreover, each looper hook has a throat which intersects the bottom cutting edge of its correspond¬ ing bill through a smooth merging arcuate portion which forms a transition area cooperating with each corresponding vertically reciprocal knife in a cut pile tufting machine. In a tufting machine incorporating modular hook bars made in accordance with this invention, individual looper hooks, as well as independent modula hook bars, may be inserted, removed, or replaced, in the looper apparatus. Brief Description of Drawings FIG. 1 is a fragmentary, sectional elevation taken along the line 1-1 of FIG. 2 longitudinally through a portion of a narrow-gauge, staggered-needle O tufting machine incorporating a cut pile looper apparatus made in accordance with this invention, and disclosing the needles and looper hooks in operative loop-forming positions; FIG. 2 is a fragmentary, front elevation of the looper apparatus, taken along the line 2-2 of FIG. 1; FIG. 3 is a fragmentary, top plan view of the looper apparatus taken along the line 3-3 of FIG. 1, with portions broken away; FIG. 4 is a fragmentary section taken along the line 4-4 of FIG. 2; and FIG. 5 is a fragmentary section taken along the line 5-5 of FIG. 2, with the looper hooks removed. Best Mode For Carrying Out The Invention Referring now to the drawings in more detail, FIG. 1 discloses a transverse needle bar 10 in a conventional multiple-needle tufting machine support¬ ing a first row of uniformly spaced front needles 11 and a second row of unifu_-~iy -Spaced rear needles 12 offset preferably mid-way between the front needles 11, to provide a uniform, narrow gauge, staggered needle tufting machine. The needle bar 10 is verticall reciprocated by conventional ceans, not shown, to cause the front and rear needles 11 and 12 to move between an upper position above the base fabric 13 to a lower position penetrating the base fabric 13 so that the needles will carry yarns, such as yarns 14 and 15, through the base fabric 13 to form loops of tufting therein. The base fabric 13 is supported upon a needle plate 16 for movement, by means not shown, in the direction of the arrow of FIG. 1, that is longitudinally from front-to-rear through the machine. The looper apparatus IS which cooperates with the needles 11 and 12 includes a transverse hook bar 20 of unique construction fixed upon a back-up bar 21, which in turn is supported upon a plurality of rocker arms 22 journaled on a rock shaft, not shown, and driven by conventional ceans connected to the rocker arms 22 for limited reciprocal movenent in x^_ K ( O synchronism with the reciprocal movements of the needles 11 and 12. The hook bar 20 has an upper portion and a lower portion and a front face which includes an upper front face portion 25, an intermediate angular front face portion 26 and a lower front face portion 27. The hook bar 20 also includes a bottom surface 28 and a rear vertical transverse surface 29. The upper portion of the hook bar 20 includes a top surface 30 and front wall portion 31 projecting upward above the main top surface 30 behind the front wall 31. The front wall 31 also includes a rearward projecting flange or lip 32. Formed in the upper portion of the hook bar 20, including the front wall 31 are a plurality of longitudinally extending, transversely spaced, verti¬ cal hook slots 35 of uniform size and of the same gauge as the needle gauge. The hook slots 35 are of relatively shallow depth, preferably occupying less than the upper half of the solid hook bar 20, but extending the full length (front-to-rear dimension of the hook bar 20. Received within each of the individual hook slots 35 is a looper hook 36 or 36'. Each looper hook 36 has a body portion including a substantially elongated, relatively straight, rearward projecting shank or shank portion 38 adapted to fit within the major portion of the corresponding slot 35. The neck or head 40 of the looper hook 36 forming a part of the body portion defines a rear vertical surface or shoulder 39 tthich intersects the shank portion 38. Projecting forward from the neck or head 40 of the looper hook 36 is an elongated bill 41 having a barbed free end portion 42 and defining a bottom cutting edge 43 intersecting the throat 44 through an arcuate or circular curved merging portion 45 of substantial radius, for example, approximately 5/32 inch. OMPI The rear face 29 of the hook bar 20 is adapted to snugly seat within a transverse recess 47, formed in the front face of the back-up bar 21. The upper edge of the transverse recess 47 terminates in a forward projecting lip or flange 48. The lip 48 projects in opposition to the rear¬ ward projecting lip 32 on the front wall 31 to define a recess above the top face 30 and between the back-up bar 21 and the front wall 31, to snugly receive an elongated transverse cap plate 50. The cross section of the cap. plate 50 is roughly an inverted T-shape so that the cap plate 50 has upper transverse recesses along its front and rear edges to define a front lower tongue 51 and a rear lower tongue 52. When the looper hooks 36 and 36' are positioned in their respective hook slots 35, and the cap plate 50 is seated in its groove with its front tongue 41 extend¬ ing beneath the rear lip 32 and the rear tongue 52 extending beneath the fσrwardly projecting lip 48, the cap plate 50 engages the top surfaces of the shank portions 38 to assist in securing the looper hooks 36 and 36' within their respective slots 35. The height of the face recess 47 is preferably equal to the conbined heights of the rear face 29 and the rear lip 52 of the cap plate 50. The hook bar 20 is held securely against the back-up bar 21 by a plurality of transversely spaced bolts 54. Furthermore, the looper hooks 36 and 36' are firmly secured within the hook bar 20, with the rear shoulders 39 tightly seated against the front tongue 51 of the cap plate 50 by means of a plurality of set screws 55 and 56. The set screws 55 and 56 are threaded through the angular front face portion 26 and through the solid portion of the hook bar 20 until the set screws engage the bottom edges of the respective shank portions 38, to securely hold the • looper hooks 36 and 36' within the hook bar 20. OMPt In the preferred form of the invention, that is in a staggered needle cut pile tufting machine, the looper hooks 36 cooperating with the rear needles 12 are identical in construction to the looper hooks 36' which cooperate with the front needles 11, except that the bills 41' of the looper hooks 36* are longer than the bills 41 by a length substantially equal to the offset longitudinal spacing between the rows of front needles 11 and rear needles 12. In the preferre form of the invention, the throats 44 of all of the loopers 36 and 36' are in transverse alignment, pursua to the teaching in the U.S. Card patent No. 4,003,321 for "CUT PILE APPARATUS FOR STAGGERED NEEDLE TUFTING MACHINE." Cooperating with each of the looper hooks 36 and 36' is a conventional cut pile knife 58 which is adapt to be reciprocated in a conventional manner in synchronism with the reciprocation of the hook bar 20 for cooperation with the respective needles 11 and 12 to catch and cut the yarns 14 and 15 in order to form cut pile loops, not shown. The back-up bar 21 may be made in several long sections for abutting end-to-end, or the back-bar 21 may extend the full width of the machine. The modular hook bars 20 are also made in sections abut¬ ting end-to-end, and are usually the same length as a corresponding back—up bar section 21. When a pair of modular hook bars 20 abut end-to- end, because of the relatively thin dimensions of the lands or side walls 62 of the slots, special provision must be made for having an uninterrupted continuation of the uniform gauge of the hooks 36, 36". As disclosed in the drawings, a double-hook nodule 64 is provided in which each hook or hook blade 65 and 66 is identical to the looper hooks 36 and 36 τ , re¬ spectively, but are permanently joined together by a transverse spacer bar 67. This spacer bar 67 is adapted to be seated within an arcuate recess 68 formed in a land at one end of the modular hook bar 20 as disclosed in the drawings. However, other means of continuing the uniform gauge of the hooks 36 from one hook bar section to the next may be employed. It will be noted that the set screws 55 and 56 are staggered in order that each set screw 55 may be in vertical planar alignment with an individual looper hook 36 while each set screw 56 may be set in vertical planar alignment with a hook 36'. By milling the hook slots 35 to a shallow depth in the upper portion of the hook bar 20 where the hook slots open through the surface 30 and also through the top surface of the front wall 31 and front face 25, substantial rigidity is obtained to securely hold the respective looper hooks 36 and 36' and to offset the cantilever pres¬ sure of the knife blades 58 exerted against the same sides of the corresponding hooks 36 and 36'. Moreover, the rigid, modular, block-type hook bars 20 seated in the face 47 and securely bolted to the back-up bar 21,' minimize any sagging throughout the length of the modular hook bar 20. Furthermore, each set screw 55 and 56 extends through a threaded portion of solid material sub¬ stantially through its entire length, until the free end of each set screw penetrates the respective hook slot 35 for engagement with the bottom edge of the shank portion 38 of a corresponding looper hook 36 and 36'. The solid cap plate 50, having its front and rear tongues 51 and 52 retained under the respective lips 32 and 48 of the hook bar 20 and the back-up bar 21, respectively, locks and holds the top edges of the shank portions 38 of the hooks 36 and 36' in secure and rigid position for operating under normally severe stresses exerted upon a looper apparatus in a tufting machine. The curved merging portion 45 in each of the OMPI hooks between the cutting edge of the bill 43 and the throat 44 provides a gradual transition portion for the movement of the knife 58 in cooperation with the cutting edge 43 of the bill 41 for severing the yarns 14 and 15. Industrial Applicability The looper apparatus 18 made in accordance with this invention enhances the accuracy of the gauge of the looper hooks 36 and 36', minimizes distortions in the hook bar 20, and also minimizes or eliminates any warping or tendency toward expansion by the lands or walls 62 of the respective hook slots 35. Both the height and depth of the solid portions of the hook bar provide effective resistance. to cantilever forces not only downward in a clockwise direction in a vertical plane, but also in transverse planes by the knives against the looper hooks, and other twisting and sagging forces caused simply by the mere weight and extensive spans of the hook bar 20 and the back-up bar 21. The upward projecting front wall 31 provides additional height to the side walls 62 of the respective slots 35 to afford additional reinforcement against the sides of the body portions of the hooks 36 and 36', and the solid cap plate 50 provides a substantial back stop for engaging the rear shoulders 39 of the respective hooks 36 and 36'.

Claims: Claims 1. In a tufting machine having means (16) for supporting the fabric (13) for longitudinal movement in the feeding direction through said machine, a plurality of transversely spaced reciprocal needles (11,12) for introducing yarns (14,15) through said base fabric (13) to form loops, a looper apparatus (18) comprising: (a) a hook bar (20) having a front face (25,26,27), a rear face (29) and a top portion (30), (b) means mounting said hook bar (20) , trans¬ versely below the plane of the base fabric (13) for longitudinal reciprocal movement between an operative position below the needles (11,12) and an inoperative position, (c) a plurality of looper hooks (36,36') , each hook having a body portion (38,40) , in¬ cluding an elongated rearwardly extending shank portion (38) and a front portion (40) , and a bill (41)* projecting forward from said front portion (40) , (d) a plurality of transversely spaced hook slots (35) having the same gauge as the needles (11,12), said hook slots (35) being formed in the top portion of said hook bar (20) and opening through said front portion (31) , (e) each hook slot (35) extending longitud¬ inally far enough to receive the shank portion (38) of each corresponding looper hook (36,36') in operative position, (f) retainer means (50) in said top portion (30) of said hook bar (20) over said hook slots (35) for holding said shank portions (38) in said corresponding hook slots (35) , and (g) threaded securing means (55,56) in the front portion (26) of said hook bar (20) for SUBSTITUTE: SHZZT adjustably engaging the body portions of said looper hooks (36,36') to urge said shank portions (38) against said retainer means (50) . 2. The invention according to claim 1 in which said hook bar (20) is made of solid material, said hook slots (35) being formed in the upper half of said hook bar, said shank portions (38) having bottom edges, said threaded securing means comprising a plurality of set screws (55,56) extending through the front portion (26) of said hook bar (20) and into engagement with the bottom edge of said shank portion (38). 3. The invention according to claim 1 in which the top portion (30) of said hook bar (20) comprises a front wall (31) projecting above the remainder of said top portion behind said front wall (31) , said hook slots (35) extending continuously through said front wall (31) , the body portion of each of said looper hooks (36,36') having a rearward facing shoulder (39) intersecting its corresponding shank portion. (38) , said retainer means comprising an elong ted cap plate (50) seated on said top portion (30) against the tops of said shank portions (38) and against the rear shoulders (39) of said looper hooks (36,36*) in operative position. 4. The invention according to claim 3 in which said front wall (31) has a rearward projecting top lip (32) and said cap plate (50) has a transverse front edge portion (51) projecting beneath said top lip (32) and abutting against said rear shoulder (39) in operative position. 5. The invention according to claim 3 in which said mounting means comprises a back-up bar (21) having a transverse front recess (47) receiving the rear face (29) of said hook bar (20), and means securing said hook bar (20) to said back-up bar (21) , said cap plate (50) having a transverse rear edge portion (52) seated in said front recess (47) above OMPI said hook bar (20). 6. The invention according to claim 5 in which said means securing said hook bar (20) to said back¬ up bar (21) comprises bolt means (54). 7. The invention according to claim 2 in which there is a set screw (55,56) for each hook slot (35), the axis of each set screw (55,56) being located in a vertical plane through the longitudinal center of each hook slot (35). 8. The invention according to claim 7 in which said front portion of said hook bar (20) comprises an angular front face portion (26), declining rearward and extending transversely of said hook bar (20) beneath said hook slots (35), said set screws (55,56), extending through said angular front face portion (26) in threaded engagement with the solid portion of said hook bar (20) for abutment with the bottom edge of each corresponding shank portion (38) in operative position. 9. In a cut pile tufting- machine having means (16) for supporting a base fabric (13) for longitudina movement in the feeding direction through said machine, a plurality of transversely spaced reciprocal needles (11,12) for introducing yarns (14,15) through said fabric (13) to form loops, a looper apparatus (18) comprising: (a) an elongated hook bar (20) having a plurality of longitudinally spaced hook slots (35), (b) means mounting said hook bar (20) trans¬ versely below the plane of the base fabric (13) for longitudinal reciprocal movement between an operative position below said needles (11,12) and an inoperative position, (c) a plurality of looper hooks (36,36'), each hook having a body portion (38,40) adapted to be received in a hook slot (35), each of said looper hooks (36,36') having a throat (44) i Afj OMP1 fty W WIIPPOO -tø O and a bill (41) projecting forward from said throat (44) , said bill (41) having a lower cutting edge (43) , (d) each of said throats (44) intersecting the lower cutting edge (43) of its correspond¬ ing bill (41) through an arcuate merging portion (45), having a substantial radius, (e) a knife (58) for each looper hook (36, 36') and (f) means supporting each knife (58) for reciprocal movement in cooperation with the throat (44), merging portion (45) and cutting edge (43) of each corresponding bill (41) for) cutting a yarn loop caught on said correspon ing bill (41) and in the cutting path of said knife (58). 10. The invention according to clain 9 in which said arcuate merging portion (45) is a circular arcuat portion. I J OREATΓ OMPI

Inventors: BEASLEY MAX M, BEASLEY, MAX, M.
Applicants: TUFTCO CORP, TUFTCO CORPORATION
Application year: 1982
Main classification: D05C15
IPC codes: D05C15