US3551969A

US3551969A - Apparatus for slitting,opening and processing tubular knitted fabric

Info

Publication number: US3551969A
Application number: US629326A
Authority: US
Inventors: Eugene Cohn; Andrew P Cecere
Original assignee: Samcoe Holding Corp
Current assignee: Samcoe Holding Corp
Priority date: 1967-04-07
Filing date: 1967-04-07
Publication date: 1971-01-05
Anticipated expiration: 1988-01-05

Abstract

THE INVENTION IS DIRECTED TO THE CONVERSION OF TUBULAR KNITTED FABRIC TO OPEN WIDTH FORM, WITH IMPROVED ARRANGEMENTS AND PROCEDUCES FOR SLITTING THE FABRIC, ENGAGING ITS SLIT EDGE MARGINS, AND THEN DIVERGENTLY ADVANCING THE EDGES TO CONVERT THE FABRIC FROM TUBULAR TO OPEN WIDTH CONFIGURATION. ADVANTAGEOUSLY, THE FABRIC MAY BE PROCESSED DURING THE CONVERSION, AS BY PERFORMING CROSS LINE REALIGNING OPERATIONS, FOR EXAMPLE.

Description

Jan. 5, 1971 E. COHN ETAL 3,551,969

APPARATUS FOR SLITIING, OPENING AND PROCESSING TUBULAR KNITTED FABRIC Filed April '2, 1 967 6 Sheets-Sheet 1 FIG. 1

INVENTORS EUGENE COHN ANDREW F! CECERE ATTORN EYS Jan. 5, 1971 E. COHN' ETAL I 3,551,969

APPARATUS FOR SLITTING, OPENING AND PROCESSING TUBULAR KNITTED FABRIC Filed April 7. 196'? 6 Sheets-Sheet v2 INVENTORS EUGENE COHN ANDREW P CECERE ATTOR NEYS Jan. 5, 1971 E. COHN ET AL 3,551,969

APPARATUS FOR SLITTING, OPENING AND PROCESSING TUBULAR KNITTED FABRIC Y Filed April '7, 196'? 6 Sheets-Sheet 5 Jan. 5, 197 1 ECOHN IETAL 3,551,969

APPARATUS FOR SLI'I'TING, OPENING AND PROCESSING v TUBULAR KNITTED FABRIC Filed April 196'? N FIG. 4

Jan. 5, 1971 E. COHN ETAL I 3,5513% APPARATUS FOR SLITTING OPENING AND PROCESSING TUBULAR KNITTED FABRIC Filed April '7, 196'? 6 Sheets-Sheet 5 FIG. 7

INVENTORS EUGENE COHN 5 ANDREW P CECERE Jan. 5, 1971 .Filed April 7.

FIG. 8

E. COHN AL 3,551,969

- APPARATUS FOR SLITTING, OPENING AND PROCESSING 'IUBULAR KNITTED FABRIC L96? 6 Sheets-Sheet 6 I l l N CD N INVENTORS 1 ANDREW F. CECERE l ATTORNEYS EUGENE COHN I iBY United States Patent O 3,551,969 APPARATUS FOR SLITTING, OPENING AND PROCESSING TUBULAR KNITTED FABRIC Eugene Cohn, Great Neck, and Andrew P. C ecere, Valley Stream, N.Y., assignors to Samcoe Holding Corporation, Woodside, N.Y., a corporation of New York Filed Apr. 7, 1967, Ser. No. 629,326

Int. Cl. D06c 3/02 US. Cl. 26-1 8 Claims ABSTRACT OF THE DISCLOSURE The invention is directed to the conversion of tubular knitted fabric to open width form, with improved arrangements and procedures for slitting the fabric, engaging its slit edge margins, and then divergently advancing the edges to convert the fabric from tubular to open width configuration. Advantageously, the fabric may be processed during the conversion, as by performing cross line realigning operations, for example.

RELATED PATENTS The present invention is closely related to the subject matter of the Sidney L. Carter et al. US. Pat. No. 3,289,- 510, and concerns cerain improvements to and over the method and apparatus of the patent.

BACKGROUND OF INVENTION In the manufacture of knitted fabrics, it is usually advantageous to produce the fabric initially in circular or tubular form, and even to carry out certain of the required processing operations while the fabric remains in tubular form. However, since many of the end uses of the fabric require it to be in open width form, provision is made in the processing sequence for slitting. the fabric tube longitudinally and then converting it to an open width configuration.

A particularly advantageous arrangement for performing the slitting and opening operations forms the subject matter of the beforementioned Carter et al. US. Pat. No. 3,289,510. The machine of the patent incorporates means for conveying the tubular knitted fabric up to a slitting knife, and tenter means for engaging the newly formed edge margins of the slit fabric. The slit edges of the fabric are conveyed forward and outward by the tenter means to convert the fabric from slit-tubular form to flat form, the fabric being permitted to drape freely, between the diverging tenters. Equipment of this type is particularly desirable because it enables the tubular fabric to be conveniently slit and opened while in wet condition, which is advantageous in many instances.

In general, the present invention is directed to the improving and perfecting of the apparatus of the beforementioned Carter et al. patent, rendering the apparatus even more desirable and suitable for slitting and opening of tubular knitted fabric on a commercial basis.

SUMMARY OF THE INVENTION As tubular knitted fabric is produced on circular knitting machines, the knitting proceeds in a spiral manner, with several rows of stitches being knitted simultaneously. Accordingly, a given row of stitches will have a spiral configuration, with a substantial longitudinal spacing or lead between adjacent convolutions, depending on the number of rows being simultaneously knitted. As a result of the essentially spiral structure of the knitted fabric tube, the rows of stitches in the initially slit and opened fabric will inherently have a bias or diagonal cast corresponding to the lead of the knitted spirals. Desirably, the fabric is processed or manipulated to eliminate this bias in the finished fabric.

In accordance with one aspect of the invention, novel and improved arrangements are incorporated into slitting and opening equipment of the type covered by the Carter et al. patent whereby, as the slit fabric is being converted to open width configuration, it is simultaneously manipulated to effect realigning of its cross lines. In one specific, advantageous form of the invention, appropriate manipulation of the fabric is achieved by diverting one of a pair of tenter chain elements relative to the other, whereby one slit edge of the fabric is required to travel a longer distance than the other during the conversion process. The extent of the diverted travel corresponds to the lead of the knitted spiral so that, at the end of the conversion process the cross lines or stitch lines of the fabric ideally are disposed at right angles to the longitudinal axis of the fabric. In a broader sense, the invention is directed in part to the performance of a combined slitting, opening and processing sequence, in which the slit fabric is suitably processed While still engaged by tenter means provided for converting the newly slit fabric to open width configuration. The processing may take place during or after the conversion stage.

In accordance with certain more specific aspects of the invention, improvements are made in slitting and opening apparatus of the aforementioned type, enabling better control and manipulation of the fabric, before and after slitting, whereby the fabric is more advantageously aligned with the tenter means in the first instance and whereby more effective control is maintained over the fabric as it is advanced and converted by the tenter means. One such improvement involves the provision of a vertically adjustable supply conveyor for the unslit tubular fabric, enabling the incoming fabric to be adjustably positioned, vertically, with respect to the tenter means. By this adjustment, it is possible to readily control the width of the edge margin of the slit fabric which is engaged by the tenter means. Another such improvement concerns the provision of a steerable control element in conjunction with the fabric supply conveyor, enabling the rotational orientation of the incoming fabric tube to be adjusted relative to the slitting knife and/or the tenter means. This permits the line of the cut to be adjusted and accurately maintained as the slitting and opening operations proceed. A further such improvement is directed to the provision of fabric retention guide means in conjunction with the tenter means, for effecting a relative manipulation of tfe tenter elements and the fabric to keep the fabric at all times properly engaged by the tenter elements.

For a better understanding of the above and other advantageous features of the invention, reference should be made to the following description of a preferred embodiment of the invention and to the accompanying drawing.

DESCRIPTION OF DRAWING tional views taken along lines 5-S and 66 respectively,

of FIG. 3.

FIG. 7 is an enlarged fragmentary view of the entry end section of the apparatus, illustrating details of certain improvement features incorporated therein.

3 FIG. 8 is a schematic representation of the apparatus of the invention, illustrating the flow of fabric therethrough, as it is converted from tubular knitted form by orienting, slitting, stripe realigning, and opening.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the drawing, the illustrated apparatus includes, in broad terms, a frame structure 10, a fabric supply conveyor means 11, a slitting knife 12, and a converting tenter means, generally designated by the numeral 13. The supply conveyor 11 is arranged to receive tubular knitted fabric 14 from a supply source (not shown) and to advance the fabric to and beyond a rotating knife 12, which slits the fabric tube longitudinally. As the edges of the slit fabric are carried past the slitting knife, they are applied to pins 15 (e.g., see FIG. 6) of the tenter means 13, and then the slit fabric edges are advanced divergently to convert the fabric to generally flat, open width configuration.

In the illustrated form of the apparatus, the slitting knife 12 is rotatably mounted by a shaft 16, at the entry end of the machine frame 10, and is arranged to be rotated at relatively high speed by a suitable drive motor. A frame structure 17 for the supply conveyor forms part of the principal machine frame 10 and is positioned generally below the slitting knife 12, extending forwardly and rearwardly thereof. Advantageously, the supply conveyor includes a pair of

narrow belts

18, 19, which are trained about a series of pulleys 2023, and pass on opposite sides of the slitting knife, closely adajacent thereto. Typically, the

conveyor belts

18, 19 may extend several feet in front of the slitting knife, so that the incoming fabric is adequately stabilized and supported, and the belts desirably also extend at least a short distance behind the slitting knife, in order to provide a measure of continued support and guidance for the fabric until it is engaged properly by the tenter means 13.

In general accordance with the beforementioned Carter et al. patent, the tenter means 13, comprising a pair of

tenter chains

24, 25, is arranged with an entry end portion closely adjacent the slitting knife 12 and a discharge end portion, substantially removed from the slitting knife, at

which the tenter chains are widely separated. At the entry end, the

chains

24, 25 are supported by

chain sprockets

26, 27 secured to

vertical shafts

28, 29. The

shafts

28, 29 are journalled and supported by the machine frame 10 and are arranged to be driven in synchronism from a suitable power source. Typically, the

shafts

28, 29 are mounted on fixed axes.

Pivotally supported by the

drive shafts

28, 29, by means of

bearings

30, 31, are tenter

arms

32, 33, which extend in divergent relation toward the discharge end of the machine frame. Near its free end, each of the

tenter arms

32, 33 is provided with a bearing pad 34, which rests upon the upper surface of a cross beam 35 forming part of the machine frame. The arrangement of the cross beam and bearing pads is such as to accommodate pivotal movement of the the tenter arms in a horizontal plane, for adjustment of the discharge-end width of the tenter means.

In the illustrated apparatus, the outer ends of the

tenter arms

32, 33 carry

bearings

36, 37 journalling and supporting

vertical shafts

38, 39. These shafts, in turn, carry

chain sprockets

40, 41, about which the

tenter chains

24, 25 are trained at the discharge end of the equipment.

Typically, the

tenter chains

24, 25 may be more or less of conventional drive chain construction, except that certain chain links are provided with L-shaped extensions, each including a downward vertical leg 44 (FIG. Secured to the extension leg is a pin plate 45, which is elongated in a horizontal direction and may carry six or seven tenter pins 15, aligned in a horizontal row and projecting generally horizontally outward, and slightly upward.

For control of the divergence of the

tenter arms

32, 33 there is provided a threaded shaft 46, which is journalled in bearings 47 on the machine frame and is oppositely threaded at its ends for threaded engagement with link 48 attached to the tenter arms. The threaded shaft 46 may be manipulated by a hand wheel 49, for example, for simultaneous widening or narrowing of the discharge end of the tenter section, in accordance with the open width dimensions of the fabric being processed.

As shown in FIGS. 2 and 3, the axes of the

chain sprocket shafts

28, 29 are located a few inches behind the effective cutting edge of the slitting knife 12, so that the slit fabric travel a few inches before being pinned upon the tenter pins 15 as they are brought successively into position travelling around the

sprockets

26, 27. A suitable herringbone roller or plate 50 or similar element is positioned adjacent the slitting knife 12 on both sides, to lie inside of the just-slit edges and prevent or remove curl. In addition, brush elements 51 may be provided to press the fabric onto the tenter pins, as the fabric proceeds into the entry end of the tenter section.

In accordance with one of the specific features of the invention, provision is made for precisely controlling the free margin of the fabric edge, which extends beyond the tenter pins 15 after application of the fabric thereto. This free margin is indicated by the reference numeral 52 in FIG. 6. To this end, one or more of the pulleys, in this instance the pulley 21, supporting the fabric

supply conveyor belts

18, 19 is adjustably mounted, as by means of a link 53 pivoted to the conveyor frame 17 and connected to a handwheel-operated threaded adjusting rod 54.

In order to increase the width of the free margin 52, the position of the pulley 21 is raised, elevating the supply conveyor belts 1-8, 19 in the region of the entry end of the tenter stage. As a result, the fabric will be supported generally at a higher level at the moment of its being pinned on the tenters. To decrease the free margin, the

conveyor belts

18, 19 are simply lowered, so that the incoming fabric is supported at a lower level relative to the tenter stage. As an additional, advantageous control over the supplied tubular fabric, a steerable guide wheel 55 is provided directly in advance of the

supply conveyor belts

18, 19 arranged to engage the inside of the fabric tube and guide it smoothly onto the belts. In accordance with the present invention, the guide wheel 55 is mounted on a suitable bracket 56, which is secured to the conveyor frame 17 by a shaft 57 or the like for pivoting movement about a vertical axis. The guide wheel 55 is arranged to rotate with the fabric and is steerable to orientations in which its axis of rotation is not at right angles to the longitudinal axis of the incoming fabric. Thus, if the incoming fabric is imprecisely aligned with the slitting knife, or if the fabric tends to "wander with respect to the slitting knife, it may be steered back into align ment, by controlling the orientation of the guide wheel axis. As indicated in FIG. 8, for example, an imaginary cutting axis 58 of the fabric can be manipulated from a misaligned position back into the desired slitting axis by appropriate steering of the guide wheel.

For a high speed installation, it may be advantageous to provide for a suitable remote control of the guide wheel orientation, but for some installations it is sufiicient merely to provide for pivoting of the bracket 56. The operator is able to grip the guide wheel through the fabric and manipulate it to the proper orientation.

To facilitate proper alignment and orientation of the fabric as'it approaches the guide wheel 55 and the supply conveyor, there is advantageously provided a blower B, which is mounted on the machine frame 10' and is arranged to direct a stream of air back into the fabric tube. This tends to inflate the fabric tube somewhat, so that it is free of folds and easy to handle. In addition, it may be desirable to provide a light source L near the entry end of the supply conveyor so that the condition and alignment of the fabric may be more readily ascertained by the operator.

In accordance with one of the particularly significant features of the invention, provision is made for manipulating the slit edges of the fabric, while they are engaged by the tenter chains, in order to relatively advance one edge and relatively retard the other edge. This enables the cross lines of the fabric to be brought into right angular relation to its longitudinal axis. As schematically illustrated in FIG. 8, for example, a typical tubular knitted fabric 14 has spirally disposed stitch lines. This structure is particularly noticeable if the fabric is knitted with cross line strips 59 of contrasting color. When the fabric is simply slit and laid open to its flat width, the cross lines 59 would be disposed at an acute angle to the axis of the fabric. In other words, the cross line at one edge would be ahead of the same line at the other edge of the fabric. To compensate for this, and to enable expedient, readily controllable reorientation of the fabric geometry, the invention provides for the controllable manipulation of the

respective tenter chains

24, 25, such that the chain having the leading side of the cross line may be diverted and caused to travel through a longer path than the chain carrying the trailing side of the cross line. Thus, when the fabric reaches the discharge end of the tenter section, one fabric edge has been retarded relative to the other a controllable amount suffieient to bring the cross lines 59 of the open width fabric into a desired, right angular disposition.

In the schematic illustration of FIG. 8, for example, the fabric is shown to have a right hand spiral construction, such that, in the slit and laid-open fabric, the left side of the fabric (viewed with the fabric going away from the viewer) leads the right side. In accordance with the invention, the left side tenter chain 24 is so guided and directed that the active reach of the chain (i.e., that portion of the chain which engages and acts upon the fabric at a given moment) is caused to be diverted to a significant extent from a straight line path to the discharge point so that the fabric edge is, in effect, delayed. The right side chain may be directed so that its active reach travels in a straight line or is diverted to a lesser extent than the left side.

Referring now to FIG. 3, each of the tenter assemblies is provided with a pair of

chain guide elements

60, 61 and 62, 63, a pair of

chain diverting elements

64, 65 and 66, 67, and spring-urged chain take-up

elements

68 and 69. As shown, the elements 60, 63 and 64-69 are conventional sprockets. However, in accordance with the invention, the elements 61, 62 are in the form of fixed, relatively large radius, arcnate plates, over which the

tenter chains

24, 26 may freely pass or snake without unduly sharp flexing. It will be appreciated that the plates or quasi-sprockets, 61, 62 may be easily disposed within the available space. Moreover, the use of such plates is especially important if only limited space is avail able for the guide elements 61, 62, for if relatively small radius sprockets were to be employed instead of plates, they would tend to unduly bend the tenter chains.

The guide sprockets 60-63 are carried by extension brackets 70, 71, mounted on the

respective tenter arms

32, 33. The inside guide plates 61, '62 are arranged with respect to the discharge

end chain sprockets

40, 41 to define a straight line portion of the active reaches of the

respective chains

24, 25. The outside guide sprockets are generally symmetrically arranged with the inside guide plates, but the chains are guided around the take-up

sprockets

68, 69 in travelling from the

main sprockets

40, 41 to the outside guide sprockets. The take-up sprockets are mounted on

pivot arms

72, 73 and are urged inward by

springs

74, 75 to maintain predetermined tension in the chains and to accommodate changes in the positions of the diverting sprockets '6467.

Advantageously, the pairs of diverting sprockets are mounted for movement in unison, by means of triangular mounting

plates

76, 77 which are pivoted at 78, 79 to the

respective tenter arms

32, 33. The free ends of the plates are supported by means of slidably engaged pairs of Z-shaped sections 80, 81 (see FIG. 4). As shown in FIG. 3, the pairs of diverting sprockets are located between the guide sprockets and the

main sprockets

26, 27 at the entry end. The sprockets of each pair are arranged so their inside edges are separated only a short distance. Thus, when the diverting sprockets pairs are arranged in neutral or symmetrical positions, the chain loops are diverted inward on both sides.

In order to advance or retard one of the tenter chains relative to the other an appropriate pair of diverting sprockets is pivoted in an appropriate direction, to either increase or decrease the extent of diversion of the active chain reach. And the opposite chain may be varied in an opposite manner. Thus, for the conditions illustrated in FIG. 8, for example, the left side tenter chain 24 would be retarded or delayed by pivoting the mounting plate 76 in a clockwise manner. This would increase the extent of the diversion of the active reach of the chain and decrease the diversion of the return reach.

If desired, all of the advancing or retarding adjustment may be applied to one chain. More advantageously, however, both chains are adjusted in a mutually contributing manner, so that part of the adjustment is effected by relatively retarding one side and the balance is effected by relatively advancing the other side. Thus in the FIG. 8 illustration, the left side tenter chain would be delayed, as above described, and the right side tenter chain 25 would be advanced, also by a clockwise pivotal adjustment of the triangular mounting plate 77, to decrease the normal diversion of the active chain reach on the right side and correspondingly increase the diversion of the return reach. The effect of the mutually contributory adjustments, as illustrated in FIG. 8, is to bring the angularly disposed cross lines 59 into the desired right angular relationship.

Most advantageously, simultaneous adjustment of the left and right side tenter chains is effected by means of a control rod assembly 82, which extends between the respective tenter assemblies and is provided at one end with a hand wheel 83. The control rod assembly 82 comprises a telescoping center section 84 which is journaled in and attached at each end to the

respective tenter arms

32, 33. Connected to each end of the center section, by suitable universal joints, are threaded

sections

85, 86, which engage threaded bushings carried by the respective mounting

plate

76, 77. The control rod sections are threaded in the same direction, such that manipulation of the hand wheel 83 causes the mounting plates to pivot simultaneously in the same direction, thus effecting mutually contributing advance-retard adjustments of the opposite side tenter chains.

When a diverting sprocket pair is adjusted, the increased chain diversion on one chain reach may not exactly equal the decreased diversion on the other reach. However, the difference can readily be accommodated by the action of the take-up

sprockets

68, 69.

As will be observed particularly in FIG. 8, the slit fabric is pinned on the tenter chains immediately adjacent the

entry end sprockets

26, 27. Accordingly, as the fabric edges are advanced, they are diverted by the

sprockets

65, 66 and then returned to the straight reaches of the tenter chains. The diversion of the fabric edges, being in an outward direction, causes the fabric to travel through an inside curve, relative to the direction in which the tenter pins 15 are projecting. The inherent nature of this fabric manipulation is such that the pinned edges will tend to draw off the tenter pins. To prevent this from occurring, the inside diverting sprockets are provided with annular fabric retention guides 87 (see FIG. 5) which are secured in concentric relation to the sprockets, spaced a predetermined distance below the chains, by means of spacer elements 88. As shown in FIG. 5, the size and positioning of the retention guides 87 is such that the circular outer edges thereof lie slightly below, and relatively aligned vertically with, the tenter pins 15. As a result, any tensions in the fabric, while it is being conveyed through the diverted chain sections, necessarily is exerted vertcally downward in the edge margin regions of the slit fabric. As will be understood, as long as the tension forces are exerted in a vertically downward direction, the fabric will remain securely engaged by the generally horizontally directed tenter pins 15.

As the fabric is progressively laid open to its flat width, the forces exerted by the fabric on the tenter means tend increasingly to be directed toward the horizontal, while at the same time tending to increase in magnitude. To prevent these forces from causing the fabric margins to become disengaged from the tenter pins, it is advantageous to provide fabric retention guide rods 89 located slightly below and in relative vertical alignment with the tenter pins, over the straight active reaches of the tenter chains and even around the guide plates 61, 62. The guide rods 89 may be suitably suspended from the

respective tenter arms

32, 33, by brackets 90 (see FIG. 6) secured to the arms and extending inward and downward therefrom. As will be observed in FIG. 6, the guide rods 89 assure that horizontally directed tension forces in the fabric are redirected so as to be applied vertically downward to the tenter pins. This arrangement is maintained until the discharge end of the equipment, where it is desired to depin the fabric.

In the apparatus principally illustrated herein, the fabric is disengaged from the tenter means substantially upon being fully laid open at the full width condition. However, it may be desirable for certain applications to extend the tenter chains onward and maintain the fabric continuously engaged throughout further processing operations, possibly including chemical processing and drying. In such cases, the tenter chains would be arranged to pass around inside sprockets 91 (FIG. 8) and extend on in parallel relation, as indicated at 92.

As a further important aspect of the invention and for those applications in which a subsequent fabric spreading or lateral stretching operation is contemplated, a variable speed drive 9 is provided for the

supply belts

18, 19, in order that those belts may be driven at sufficiently high speed to overfeed the fabric onto the

tenter chains

24, 25. The rate of overfeed will be a function of the degree of increase in width and concomitant shortening in length of the fabric during the spreading step.

As will be understood, the invention provides for advantageous improvements in the equipment and process of the Carter et al. US. Pat. No. 3,289,510. The improvements render the prior equipment even more useful for higher speed, continuous production runs and enable certain fabric processing activities, such as cross line realigning, to be performed in the course of handling the fabric on the tenter means, which are required in any event for laying open the slit fabric. The basic concepts of the invention are of course subject to expression in a variety of specific ways.

What is claimed is:

1. In a fabric slitting and opening apparatus of the type comprising means for supplying tubular knitted fabric, means for slitting longitudinally the fabric tube, and tenter means for engaging the slit edges of the fabric and advancing said edges divergently to convert said fabric from tubular to open width form, the improvement characterized by (a) said tenter means being disposed in a generally horizontal plane,

(b) said tenter means having projecting tenter pins,

(c) said tenter pins, at the entry end of said tenter means, projecting generally horizontally for engagement with the edge margins of slit fabric, with the fabric suspended loosely between opposite sets of tenter pins, and

(d) fabric retaining guide means disposed along at least portions of said tenter means, generally parallel thereto and below the tenter pins,

(e) said fabric-retaining guide means engaging said fabric below said tenter pins and diverting the engaged portions of the fabric downward in relation to said tenter pins,

(f) whereby a relatively large angle is maintained between the tenter pins and the edge portion of the fabric immediately below the tenter pins.

2. A fabric slitting and opening apparatus according to claim 1, further characterized by:

(a) said fabric retaining guide means comprising means for guiding the edge margin of the fabric.

3. In a fabric slitting and opening apparatus of the type comprising means for supplying tubular knitted fabric, means for slitting longitudinally the fabric tube, and tenter means for engaging the slit edges of the fabric and advancing said edges divergently to convert said fabric from tubular to open width form, the improvement characterized in that said tenter means comprises:

(a) a pair of chain sprockets including an entry end sprocket and a discharge end sprocket, for each of said fabric edges,

(b) a tenter chain trained about each of said pair of sprockets and having a divergently related active reach extending from near said slitting means toward the discharge end of the apparatus, and

(c) a diverting sprocket positioned along the active chain reach of each tenter chain and engaging said chain to divert said chain from its normal path, whereby to increase the length of travel of said chain in traversing said active chain reach,

(d) means mounting the diverting sprockets for adjustable positioning, for variably controlling the length of travel of said chain over said active chain reach,

(e) interrelated adjusting means for said diverting sprockets,

(f) said interrelated adjusting means being arranged to effect opposite adjustments of the respective diverting sprockets, whereby the length of travel of one tenter chain over its active chain reach is increased while the length of travel over the active reach of the other chain is decreased.

4. In a fabric slitting and opening apparatus of the type comprising means for supplying tubular knitted fabric, means for slitting longitudinally the fabric tube, and tenter means for engaging the slit edges of the fabric and advancing said edges divergently to convert said fabric from tubular to open width form, the improvement characterized in that said tenter means for at least one fabric edge comprises:

(a) a pair of chain sprockets, including an entry end sprocket and a discharge end sprocket,

(b) said chain sprockets being carried by an arm arranged for pivoting adjustment about the axis of the entry end sprocket,

(c) a tenter chain trained about said sprockets and having a divergently related active chain reach extending from near said slitting means toward the discharge end of the apparatus,

(d) said tenter chain being trained in a closed loop about said chain sprockets,

(e) a pair of guide members being mounted on said arm for engaging and guiding the chain between said entry end and discharge end chain sprockets,

(f) a pair of diverting sprockets positioned along said active chain reach adjacent said guide members for engaging and diverting opposed chain reaches of the closed loop from its normal path, and

(g) means for effecting adjustable movement of said diverting sprockets in unison relative to the chain loop whereby, as the length of travel of one chain reach is increased, the length of the other is decreased.

5. A fabric slitting and opening apparatus according to claim 4, further characterized by (a) said diverting sprockets being positioned in straddling relation to the chain loop, between said guide members and the entry end chain sprocket,

(b) the separation of said diverting sprockets being substantially less than the normal separation of the chain reaches in the region of said diverting sprockets, whereby said chain reaches are diverted toward each other, and

(c) said diverting sprockets being connected together for movement in unison in directions generally transverse to the travel of the chain reaches.

6. In a fabric slitting and opening apparatus of the type comprising means for supplying tubular knitted fabric, means for slitting longitudinally the fabric tube, and tenter means for engaging the slit edges of the fabric and advancing said edges divergently to convert said fabric from tubular to open width form, the improvement characterized by:

(a) said tenter means being disposed in a generally horizontal plane and having generally horizontally directed tenter pins arranged to engage the opposite edge margins of the slit fabric initially in narrowly separated regions and to advance said edges divergently, with said fabric suspended therebetween,

(b) said tenter means including a pair of flexible loop elements extending generally along divergently related paths,

(c) a tenter guide element being associated with one of said flexible loop elements for diverting said one of said flexible loop elements in an arcuate path, and

(d) fabric retaining guide means disposed along at least portions of said one element, generally parallel thereto and below the tenter pins,

(e) said fabric retaining guide means comprising a circular element carried by said tenter guide element and operative to guide the fabric generally in the arcuate path of said one of said flexible elements,

(f) the edge areas of said fabric being guided generally directly downward from the tenter pins by said retaining guide means to effect retention of the fabric on the generally horizontally directed pins notwithstanding laterally directed tensions in the fabric.

7. In a fabric slitting and opening apparatus of the type comprising means for supplying tubular knitted 10 fabric, means for longitudinally slitting the fabric tube, and horizontally disposed tenter means having generally horizontally directed tenter pins for engaging opposite edge margins of the slit fabric and advancing the engaged edges divergently, with the body of the fabric suspended therebetween, the improvement comprising:

(a) fabric edge retaining means for counteracting the progressively increasing lateral forces tending to disengage said fabric edges from said generally horizontally disposed tenter pins,

(b) said fabric edge retaining means being disposed along at least portions of said tenter means and engaging the edge portions of said fabric below said tenter pins,

(c) said fabric edge retaining means generally imparting an obtuse angle to the fabric between its edge portions immediately below the tenter pins and its body portion,

(d) said obtuse angle being progressively smaller as the fabric is opened and generally approaches a right angle when the fabric is fully opened.

8. A fabric slitting and opening apparatus according to claim 7, further characterized by:

(a) said fabric retaining guide means comprising elongated rod-like elements disposed along portions of the fabric conveying reaches of said tenter means.

References Cited UNITED STATES PATENTS 380,139 3/1888 Scholfield 2661(A)UX 727,443 5/1903 Ratignier et al. 2652 764,254 7/1904 Ratignier et al 26-52 848,416 3/1907 Voland et al. 2651.3 2,773,296 12/1956 Cohn et al. 2655 2,831,234 4/1958 Vitz 26-57(A)UX 3,289,510 12/1966 Carter et a1. 2655(UC)UX 3,160,340 12/1964 Menkel 2661 (A) (X) FOREIGN PATENTS 354,110 8/1931 Great Britain 2657 (A) 802,750 10/1958 Great Britain 2655 21,864 5/1883 Germany 2661 (A) 0 ROBERT D. MACKEY, Primary Examiner US. Cl. X.R.