United States Patent: 3552248

[US Patent & Trademark Office, Patent Full Text and Image Database]

( 711459 of 711459 )

United States Patent	3,552,248
Pernick	January 5, 1971

TENTER MEANS FOR FABRICS AND THE LIKE

Abstract

The invention is directed to a novel pin tenter apparatus, in which tenter pins, arranged for engagement with the edges of a fabric or other web, are pivoted on the tenter chain and are arranged for mechanically actuated movement between generally horizontal and generally vertical positions. The arrangement enables the tenter pins to pick up a vertically draped web, draw it out horizontally, and then release it. The novel tenter mechanism has broad application, but is particularly useful for applications such as the slitting and opening of tubular knitted fabric.

Inventors:	Pernick; David (Brooklyn, NY)
Assignee:	Knitting Specialty Machinery Corporation (Brooklyn, NY)
Appl. No.:	04/792,714
Filed:	January 21, 1969

Current U.S. Class: 83/151 ; 26/73; 26/82; 26/87; 26/89; 26/91; 26/96; 83/155; 83/175; 83/435

Current International Class: D06C 3/00 (20060101); D06C 3/02 (20060101); D06H 7/08 (20060101); D06H 7/00 (20060101); D06c 003/02 ()

Field of Search: 83/151,155,175,425,435 242/56.2,62 26/1,55,61A,62A,62C

References Cited [Referenced By]

U.S. Patent Documents


1085538	January 1914	Burgess et al.
2787822	April 1957	Morrill
3196723	July 1965	Cohn et al.
3203386	August 1965	Briggs
3289510	December 1966	Carter et al.
3436796	April 1969	Coates

Foreign Patent Documents


4,819	Dec., 1876	GB
789,799	Nov., 1935	FR

Primary Examiner: Lawson; William S.

Claims

I claim:

1. A tenter apparatus for reorienting, conveying and processing web materials, which comprises:

a. a pair of nonuniformly spaced tenter conveyors;

b. support means extending from said conveyors at a plurality of closely spaced locations;

c. tenter element carriers mounted on said support means for pivotal movement relative thereto;

d. web tenter elements mounted on said carriers and movable therewith between predetermined angular orientations, in which said tenter elements generally project toward one another in the same general plane at minimally spaced portions of said conveyors and said tenter elements project parallel to or away from one another in different planes at maximumly spaced portions of said conveyors; and

e. carrier guide means associated with said conveyors for controllably determining the angular orientations of said tenter elements relative to said conveyors.

2. A tenter apparatus according to claim 1, further characterized by:

a. said tenter element carriers being biased to pivot in a first direction toward limit positions; and

b. said carrier guide means comprising means for controllably urging the carriers in the second direction into displaced orientations.

3. A tenter apparatus according to claim 2, further characterized by said carrier guide means comprising camlike means disposed along at least portions of the conveyors, whereby the orientations of the carriers is controllably determined in accordance with the positions of the respective carriers in the travel path of the conveyors.

4. A tenter apparatus according to claim 2, further characterized by:

a. locking levers being associated with the respective carriers and the support means therefor;

b. said locking levers being operative to lock said carriers in predetermined displaced orientations;

c. said carrier guide means being operative to pivot said carriers into said predetermined displaced orientations to effect locking of said carriers; and

d. carrier release means being disposed along the paths of said conveyors and operative to activate said locking levers to release said carriers for pivotal movement toward their respective limit positions.

5. A tenter apparatus for reorienting conveying and processing web materials, which comprises:

a. a pair of nonuniformly spaced tenter conveyors;

b. tenter element carriers mounted on said conveyors at a plurality of closely spaced locations;

c. web tenter elements movably mounted on said carriers; and

d. guide means associated with the conveyors for controllably determining the orientation of said tenter elements in a manner in which said tenter elements generally project in the same general plane at minimally spaced portions of said conveyors and said tenter elements project parallel to or away from one another in different planes at maximumly spaced portions of said conveyors.

6. A tenter apparatus according to claim 5, further characterized by:

a. said carriers being independently biased for movement toward a first angular orientation;

b. said guide means comprising means for moving said carriers toward a second angular orientation in accordance with the travel of said conveyors;

c. means being provided for locking said carriers in said second angular orientations independently of said guide means; and

d. means being provided for releasing said locking means in accordance with the travel of said conveyors.

7. A tenter apparatus according to claim 6, further characterized by:

a. said conveyors comprising chain loops mounted to be driven in the same plane or in parallel planes;

b. said carriers being mounted on said said conveyors for pivotal movement relative thereto in planes disposed generally at right angles to said same or parallel planes; and

c. said carriers being controllably pivotable through an angle of approximately 90.degree. .

8. A tenter apparatus according to claim 7, further characterized by:

a. at least certain links of said chain loops either carrying or constituting carrier support arms;

b. said carriers being pivoted on said arms;

c. cooperating means being provided on said carriers and arms forming stop positions for said carriers and defining the said first angular orientations thereof; and

d. cooperating locking means being provided on said carriers and arms for holding said carriers in said angular orientations.

9. A tenter device, for incorporation in a web tenter, which comprises:

a. a support arm adapted to constitute or to be carried by a link of a tenter chain;

b. a tenter element carrier pivotally mounted on said support arm for movement throughout a large angle;

c. cam follower means on said carrier for effecting controlled pivotal movement thereof relative to said support arm;

d. means to bias said carrier to pivot to a first angular orientation; and

e. locking means acting between said arm and carrier to retain said carrier in a second angular orientation.

10. A tenter device according to claim 9, further characterized by:

a. said locking means comprising a lever pivotally mounted on said support arm and biased to rotate toward a locking position; and

b. said lever having a cam-engageable arm for rocking the lever to a release position.

11. A tenter device according to claim 9, further characterized by:

a. said carrier having secured thereto a pin plate mounting a plurality of tenter pins; and

b. said carrier being mounted for pivotal movement throughout an angle on the order of 90.degree. .

12. An apparatus for slitting and opening tubular knitted fabric or the like, which comprises:

a. an input means having a supporting surface of substantially smaller width than the circumference of the fabric tube, arranged to be received within the tube and enabling the tube to drape loosely below said supporting surface;

b. a fabric cutter for slitting the tube adjacent the discharge of the input means;

c. opposed tenter conveyor means disposed on opposite sides of the cutter;

d. said tenter conveyor means having first portions closely approaching said cutter from opposite sides and having divergently directed second portions on the downstream side of the cutter;

e. said conveyor means including tenter pins for engagement with the cut edge margins of the fabric; and

f. said tenter pins being generally horizontally directed in said first conveyor portion and being generally vertically directed in said second conveyor portion.

13. A slitting and opening apparatus according to claim 12, further characterized by:

a. said first and second tenter conveyor portions comprising portions of continuous tenter chains;

b. said tenter pins being pivotally mounted on said chains; and

c. camlike means being provided for controllably reorienting the angular disposition of the tenter pins as they advance from the first to the second conveyor portions.

14. A slitting and opening apparatus according to claim 13, further characterized by:

a. said tenter pins being mounted by pivotable pin carriers; and

b. cam means being disposed along at least a portion of the tenter chains between said first and second portions thereof for effecting controlled angular reorientation of the carriers in accordance with the forward travel of the tenter chains.

15. A slitting and opening apparatus according to claim 14, further characterized by:

a. locking means being associated with each of the respective pin carriers for holding said carriers in reoriented angular disposition independently of said camlike means; and

b. means being provided adjacent the discharge ends of said conveyors for effecting release of said locking means.

16. A tenter apparatus for converting a loosely draped fabric to horizontal, laterally extended form, which comprises:

a. a pair of divergently related tenter chains, each mounted for operation in a generally horizontal plane;

b. said chains having a discharge-end separation corresponding to the full open width of the fabric and an entry-end separation of significantly narrower dimensions;

c. a large plurality of tenter pin carriers mounted by said chains for independent pivoting movement in vertical planes;

d. control means for changeably orienting said carriers about their respective pivot axes whereby the tenter pins supported by said carriers may be controllably moved from a first, generally horizontal disposition to a second, generally vertical disposition; and

e. said control means being operative to orient said pins in their generally horizontal dispositions when said pins are adjacent the entry-end region of said chains, and to reorient said pins toward their generally vertical dispositions as said chains progress divergently from said regions.

17. An apparatus according to claim 16, further characterized by said control means including:

a. spring means independently associated with said carriers and urging them to pivot in one direction;

b. camlike means for pivoting said carriers in the other direction in accordance with advancement of the tenter chains;

c. locking means for holding said carriers in predetermined displaced positions against the action of said spring means and independently of said camlike means; and

d. means for releasing the locking means for the respective individual carriers in accordance with advancement of the chains.

18. An apparatus according to claim 17, further characterized by:

a. said spring means urging said carriers into a limit position in which the tenter pins are generally horizontal;

b. said camlike means being operative to pivot the carriers upward, to orient the tenter pins in generally vertical disposition in accordance with advancement of the chains;

c. the locking means engaging the carriers to hold the pins in generally vertical disposition independently of the camlike means during portions of the advancing movement of the chains; and

d. said means for releasing being effective to release individual carriers in succession as they near the discharge-end region of the conveyor chains.

19. An apparatus according to claim 18, further characterized by the means for releasing being so arranged and positioned, relative to the discharge end of the tenter apparatus as effect withdrawal of the tenter pins from the fabric by reason of the downward pivoting of the pin carriers relative to the horizontally disposed fabric.

Description

BACKGROUND AND SUMMARY OF INVENTION

In the handling and processing of web materials, particularly fabrics, there is frequently employed a tenter facility, which includes means for engaging the opposed selvages or edge margins of the web material. The thus engaged edges of the material are controllably advanced in the desired manner and may also, if desired, be subjected to a degree of lateral or widthwise tension. A common form of tenter apparatus is the so-called pin tenter, which engages the web edges in a more or less continuous fashion by means of a large multiplicity of tenter pins projected through the web material at its edges.

In a typical pin tenter apparatus, there are opposed tenter chains, spaced a predetermined distance apart and typically arranged to be driven in synchronism. The links of the tenter chains carry individual pin plates from which project a plurality, perhaps a dozen or two, of needlelike tenter pins, usually arranged in a plurality of rows. The web material, which is typically fabric, is impaled on the tenter pins in a suitable fashion, and thereafter can be conveyed and subjected to processing manipulations by the tenter chains.

In its most basic aspect, the present invention is directed to improvement in the tenter facilities, relating specifically to the mounting of the tenter pins with respect to the supporting and conveying chains. More particularly, this aspect of the invention is directed to the mounting of the tenter pins in pivotable relation to the individual links of the tenter chains, in a manner enabling the tenter pin plates to pivot in a plane disposed at right angles to the principal plane containing the tenter chains themselves. Thus, in a typical tenter apparatus incorporating the invention, the tenter chains will be disposed in a generally horizontal plane, and the tenter pin plates are supported for pivotal movement in a vertical plane. The tenter pin plates are thus pivotable from a conventional position, in which the tenter pins are projected generally vertically upward, to a position in which the pins are generally horizontal, projecting toward each other from opposite sides of the tenter frame.

A further broad objective of the invention resides in the provision of a novel and improved tenter apparatus containing pivotable pin plates as described above, which incorporates a novel and advantageous arrangement for manipulating the tenter pin plates throughout their range of operative positions. Desirably, this includes spring arrangements biasing the pin plates in one direction, cam means for controllably repositioning the tenter pin plates in opposition to the biasing springs, and a locking facility for holding the tenter pins in a predetermined principal operating position. The locking means is arranged to be released by a suitable trip mechanism at a desired point in the operating cycle, causing the pin plates to be pivoted by their biasing springs back to their previous operating positions. The overall arrangement is uniquely simplified, yet affords an unusual and highly advantageous new operating mode for pin tenter mechanisms.

Although the new tenter arrangements generally described above may be used to advantage wherever it is desired to provide for multiple pin orientations in a pin tenter mechanism, one of the especially advantageous uses for the new tenter mechanism is in the slitting and opening of tubular knitted fabric. In U.S. Pat. No. 3,289,510 granted Dec. 6, 1966 to Sidney L. Carter, et al., there is disclosed and claimed an advantageous form of apparatus for slitting a tube of knitted fabric and converting it to an open width form. This apparatus includes a preliminary or input conveyor arranged to engage and support a narrow portion of an incoming tube of fabric. The remainder of the fabric tube drapes loosely below the conveyor. The fabric is conveyed in this manner to a cutting knife, which slits the fabric tube. At this point, the downwardly draped portions of the fabric are engaged, on opposite sides of and closely adjacent to the cutting knife, by opposed sets of generally horizontally disposed tenter pins carried by suitable tenter chains. The tenter chains are then divergently directed, such that the now-cut edges of the fabric are separated substantially to the full width of the cut fabric. At the discharge end of the tenter chain, the fabric is in the desired, open width form.

In accordance with an important aspect of the invention, a slitting and opening apparatus of the general type envisioned by the Sidney L. Carter, et al. U.S. Pat. No. 3,289,510 may be significantly improved by the utilization of a controllably pivotable tenter pin mounting as provided in accordance with the broader aspects of the invention. Such an arrangement enables the tenter pins to be more or less horizontally inwardly directed in the region where the fabric is initially picked up on the pins, affording the most efficient pickup of the then vertically disposed fabric margins. Thereafter, as the slit fabric web is converted from its loosely draped condition to its horizontally disposed, open width form, the tenter pins may be reoriented into generally vertical, upwardly disposed positions, for most efficient control of the fabric, and without the likelihood of the fabric becoming "depinned" as a result of the horizontally directed reaction forces exerted by the fabric. Thus, in the arrangement of the invention, the tenter pins may be first disposed in an optimum position for engagement and pickup of the fabric, and thereafter reoriented to an optimum position for supporting, conveying, and applying widthwise tension to the fabric.

In a tenter apparatus incorporating the new tenter pin arrangement of the invention, whether or not the apparatus be used for slitting and opening the tubular knitted fabric, depinning of the fabric at the end of the tentering operation is efficiently accomplished by release of the locked tenter pins for rapid pivoting movement from generally vertical to generally horizontal positions, both permitting and encouraging the fabric to be withdrawn from the pins. In the case of the slitting and opening apparatus described immediately above, this also serves to reorient the pins in the desired position for engagement of the newly slit fabric during the recycling of the tenter chains.

For a better understanding of the above and other objects and advantages of the invention, reference should be made to the following detailed description and to the accompanying drawing.

DESCRIPTION OF DRAWING

FIG. 1 is a top plan view of an advantageous form of slitting and opening apparatus for tubular knitted fabrics, and the like, incorporating the new tenter means.

FIG. 2 is an elevational view of the apparatus of FIG. 1.

FIG. 3 is a perspective representation of cam arrangements incorporated in the apparatus of FIG. 1 for effecting controlled reorientation of tenter pins in accordance with the invention.

FIG. 4 is a greatly enlarged, fragmentary top plan view of the apparatus of FIG. 1, showing the arrangement of tenter pins in the region of initial engagement of the fabric thereby.

FIG. 5 is an enlarged, fragmentary cross-sectional view taken generally on line 5-5 of FIG. 4.

FIG. 6 is an enlarged, fragmentary cross-sectional view similar to FIG. 5, but illustrating the apparatus at a state "downstream" of the region of initial fabric engagement by the tenter means.

FIG. 7 is an enlarged fragmentary cross-sectional view taken generally on line 7-7 of FIG. 1.

FIGS. 8 and 9 are fragmentary cross-sectional views taken generally along lines 8-8 and 9-9 respectively of FIG. 7.

DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

In the following description, the new tenter pin mechanism, forming the broader aspects of the invention, will be described in the environment of an apparatus for slitting and opening tubular knitted fabric. Nevertheless, it is to be understood that the tenter mechanism itself may be utilized in a variety of applications in which tenter means are incorporated.

Referring now to the drawing, and initially to FIGS. 1 and 2 thereof, the slitting and opening apparatus as shown comprises a suitable frame, generally designated by the numeral 10, which mounts an input conveyor means 11, a cutting knife 12, a pair of opposed tenter chains 13, 14, and a suitable windup facility 15. In accordance with the disclosure of the Sidney L. Carter et al. U.S. Pat. No. 3,289,510, tubular knitted fabric is fed onto and supported on the input conveyor 11, which typically comprises a pair of spaced V-belts 16. The fabric tube is draped loosely over the belts 16 and hangs freely downward therefrom, much in the manner indicated in FIG. 5.

The fabric tube is advanced by the input conveyor 11 onto a pair of spaced upper guide bars 17 (FIG. 5) which straddle and extend beyond the cutting knife 12 and provide a supporting plane for the fabric while it is being cut. A similar pair of lower guide rails 18 are disposed directly below the guide rails 17 and provide support for fabric margins to be engaged by tenter pins.

With reference to FIG. 4, fabric travelling from left to right over the guide bars 17 is engaged and cut by the knife 12 approximately at the point designated C. Just shortly in advance of the cutting point C, adjacent margin areas of the fabric are engaged by tenter pins 20, which project horizontally inward from the respective tenter chains 13, 14. As will be observed in FIGS. 1 and 4, the tenter pins 20, which are supported in multiples from conventional tenter pin plates 21, are carried by sprockets 22, 23 into positions in which the pins 20 project inwardly through the vertical planes defined by the guide bars 17, 18. The fabric draped over and supported by these guide bars is thus impaled upon the pins, shortly before the fabric is severed by the cutting knife 12. The tenter chains 13, 14 then proceed divergently, carrying the now-slit fabric along and converting it to its open width condition.

As will be understood by reference to FIGS. 5 and 6, when the fabric F is initially engaged by the tenter pins 20, the fabric is draped over the guide bars 17. Thus, the optimum orientation of the tenter pins 20, not only for effecting initial pinning of the fabric, but also for supporting the weight of the draped fabric after severing by a cutting knife 12, is the generally horizontal, inwardly directed disposition indicated in FIG. 5. Typically, conventionally available tenter pin plates 21 will provide for a slight canting of the tenter pins, so that with the plates 21 themselves disposed in a vertical plane, the pins 20 will be canted slightly upward, and this is a desirable condition, as will be understood.

As the tenter chains 13, 14 progress away from the cutting station and diverge toward the full-width dimension of the fabric, the pull of the fabric on the pins changes direction, from an initially vertical direction to an ultimate horizontal direction, eventually resulting in the premature and uncontrolled depinning of the fabric, unless special retaining means are provided

In accordance with the present invention, optimum tentering conditions are maintained throughout the entire tentering cycle by providing for the controlled pivoting movement of the tenter pins from an initial, generally horizontal directed position as indicated in FIG. 5 to a subsequent, generally vertically disposed position indicated in FIG. 6. Thus, while the FIG. 5 orientation of the pins is optimum for fabric engagement and for the initial conveyance of the fabric, the FIG. 6 disposition of the pins is optimum for subsequent stages of the tentering operation, as it enables the tenter to apply force across the full width of the fabric without any tendency for the fabric being prematurely depinned.

In the tenter arrangement of the invention, alternate links of the tenter chains are comprised of support brackets 24, the lower surfaces 25 of which are arranged to be supported throughout all or part of the traverse of the chains by structural members 26. Each link bracket 24 includes spaced arms 27 which pivotally support both a tenter pin carrier 28 and a locking lever 29.

Advantageously, the tenter pin carriers 28 are pivoted by pins 30 and are biased to pivot in a downward direction, by means of coil springs 31. Cooperating abutment surfaces 32, 33 on the arms 27 and on the pin carrier 28 limit the downward pivoting movement of the pin carrier, and the arrangement is such that, when the carrier is in this downward limit position, pin plates 21 mounted thereon are substantially vertically disposed, as reflected in FIG. 5.

Each of the pin carriers 28 advantageously is provided with a locking notch 34 arranged for engagement with a locking foot 35 carried by and projecting downward from each of the locking levers 29. By means of suitable springs 36, the locking levers 29 are biased in a downward direction, into stop positions reflected in FIG. 5. However, when the pin carrier arms 28 are rotated upwardly about their pivot shafts 30, the locking feet 35 are engaged by cam surfaces 37 on the pivotable pin carriers and these surfaces serve to cam the locking levers in an upward direction. The geometry of these respective parts is such that, when the pin carriers 28 are pivoted into positions in which the pin plates 21 are substantially in horizontal planes, the locking feet 35 drop into the notches 34, thereby locking the tenter pins in their generally vertical orientations, as reflected in FIG. 6.

To effect controlled rotation of the pin carriers 28, for horizontal-to-vertical reorientation of the tenter pins 20, the mechanism of the invention advantageously includes an elongated cam plate 38 (FIG. 3) which is supported at a plurality of points by rods 39 projecting from the chain support structure 26. As reflected in FIGS. 3, 5 and 6, the elongated cam plates 38 extend along each of the tenter chains 13, 14, from a region opposite the point of initial fabric engagement to a point suitably downstream thereof, at which it is desired to have the tenter pins reoriented to their generally vertical positions.

As shown in FIGS. 5 and 6, each of the pin carriers 28 carries a cam follower arm 40, which is arranged to engage and follow the contour of an associated cam plate 38. Thus, in the condition of the apparatus reflected in FIG. 5, the pin carriers 28 are held by the springs 21 in their stop positions, with the pin plates 21 oriented in vertical planes. The cam follower arms 40 face the vertically oriented surfaces of the cam plates 38. However, in this orientation of the pin carriers, the cam plates 38 do not bear with any force upon the cam followers 40. The curvature of the cam plates 38 is such that, as the tenter chains advance in the "downstream" direction, the plates gradually urge the cam follower arms 40 in an upward pivoting direction until, in the ultimate position reflected in FIG. 6, the carrier arms 28 have been pivoted through 90.degree. and have been engaged by the locking feet 35. Once in a locked position, the pin carriers 28 no longer require the support of the cam plates 38, so the cam plates need not extend the full length of the tenter chains.

If desired, the cam plates 38 may be contoured in a manner such that the pin carriers are located gradually over a substantial length of the forward travel of the tenter chains. On the other hand, the cam plates may be contoured to effect relatively rapid upward pivoting of the pin carriers, the maximum rate of upward pivoting being determined by a tendency, at some point, for the fabric to be depinned. In other words, if a pin carrier is pivoted upward too abruptly, relative to the carrier immediately adjacent to it, and following it, the fabric may be lifted by the leading carrier off of the pins of the adjacent following carrier. In practice, it has been found that the pin carriers 28 may be pivoted through an angle of 90.degree. within a linear travel on the order of one foot without experiencing any tendency for depinning of the fabric.

In the illustrated arrangement, the tenter chains 13, 14 are adjustably disposed in divergent relation, such that the edge margins of the fabric are conveyed by the tenter pins into a generally flat, full open width condition. In addition, and as will be more fully described in my copending application Ser. No. 792,656, filed Jan. 21, 1969, the tenter chains 13, 14 include articulated parallel sections 13a, 14a arranged to convey the fabric in a forward direction, while maintaining it at a predetermined width. While thus conveyed, the fabric may, for example, be exposed to steam from a steam box 41, cooled by an air nozzle 42 and, after depinning, conveyed over guide rollers 43, 44 to the windup 15, where the fabric is gathered is a wound roll 45 of full width material. If the fabric initially is in wet condition, it may be carried by the tenter sections 13a, 14a through a suitable dryer stage, before being depinned and wound up.

As will be understood, after the pinned fabric has advanced a short distance along the divergent portions of the tenter chains 13, 14, the pin carriers 28 have been pivoted into their locked positions, in which the tenter pins 20 are in a generally vertical orientation. The cam plates 38 thus may be of limited length, and the pin carriers 28 will remain in their locked positions throughout the further divergent portions and the subsequent parallel portions of the tenter chain travel.

As the pin carriers 28 approach the discharge end of the tenter chains 13, 14, the upstanding arms 46 of the locking levers 29 are engaged by releasing cams 47. As the tenter chains continue to advance, the arms 46 are displaced outwardly by the cams 47, raising the locking levers and ultimately releasing the pin carriers 28. The released carriers are shaped downwardly by their respective coil spring 31, so that the tenter pins 20 reassume their generally horizontal disposition. This rapid downward pivoting movement of the unlocked pin carriers 28 not only tends to withdraw the pins 20 from the fabric, but also encourages the fabric release by reason of the eventual horizontal disposition of the pins. Particularly in the handling of knitted fabric, where there is some elasticity to the laterally distended fabric, the fabric will literally draw itself off of the pins as they are brought into horizontal orientation.

In the tenter arrangement illustrated herein, the entry ends of the tenter chains 13, 14 are arranged for pivoting movement about fixed vertical axes, forming the rotational axes for the main sprockets 22, 23. These sprockets are carried by shafts 47 (FIG. 5) driven through pairs of beveled gears 48 by a drive shaft 49. The sprockets 22, 23 thus form the power input for the tenter chains.

The outer portions of the tenter chains 13, 14 are movably supported by means of rollers 50 and guide tracks 51 disposed below the articulated parallel extensions 13a, 14a. The upstream guide tracks 51 are proportioned and disposed to provide a supporting surface which is inclusive of an arcuate path followed by the rollers 50, and the downstream guide tracks 51 are disposed in parallel relation to the upstream pair. By means of a pair of threaded control shafts 52, 53 arranged for simultaneous control manipulation by handwheel 54 and connecting chain 55, the articulated tenter chain extensions 13a, 14a may be moved inward or outward in substantially parallel relation. Pivoted connecting arms 56, 57, are threadedly engaged with the shafts 52, 53 and are connected to the supporting structure for the tenter chain extensions, for accommodating the arcuate motion of the chain extensions during adjustment. As will be understood, the desired width adjustment of the tenter chain extensions 13a, 14a is a function of the width of the fabric being processed.

In typical operation of the apparatus of the invention, the cutting knife 12 is driven at high speed by means of a suitable motor 58. The tenter chains are driven by a main drive motor 59, which is connected by a belt 60 and pulley 61 to the main tenter drive shaft 49. The input conveyor 11 is driven off the tenter drive shaft 49 through a system comprising a variable pulley 62, belts 63, 65, 67, and shafts 64, 66, 68. The arrangement is such that the tenter chains 13, 14 are driven at the basic "machine speed," determined by the speed of the main drive motor 59 and a variable output control 69 therefor. The input conveyor 11, is in turn, driven at a speed which may be varied relative to machine speed by control of the variable pulley 62. Desirably, the input conveyor 11 is arranged to operate at a slightly higher speed than the tenter chains 13, 14, to provide for a degree of overfeeding of the fabric onto the tenter chains.

The variable output 69 of the drive motor 59 has a second power takeoff comprising a belt 70, shafts 71--73, a belt 74, a variable pulley 75, and belt 76 leading to the windup device. By appropriate control of the variable pulley 75, the speed of the windup may be varied relative to the basic machine speed, so that controlled amounts of tension can be imparted to the fabric at the windup stage, enabling a uniform, square-ended roll of material to be formed.

SUMMARY OF OPERATION

Tubular fabric, in either wet or dry form, is advanced over the input conveyor 11 and carried up to the cutting knife 12, where the fabric is split longitudinally. Immediately in advance of the splitting operation, and as the fabric is being conveyed over pairs of guide bars 17, 18, the fabric is engaged by opposed pairs of horizontally, inwardly directed tenter pins 20. Desirably, the fabric is in a slightly overfed condition as it is initially engaged by the tenter pins.

After slitting, the fabric is divergently conveyed by the tenter chains 13, 14, to convert the fabric from its initial, tubular form, to a full, open width form.

The tenter pins are mounted pivoted pin carriers 28 and, after an initial short advancing movement of the tenter chains from the fabric pickup region, the pivoted carriers are engaged by cam tracks carried in fixed relation to the tenter chain supports. As the chains continue to advance, the individual tenter pin carriers are gradually pivoted through an arc of about 90.degree. , so that the tenter pins are disposed in a generally upright position. Thereafter, as the tenter chains continue to convey the pinned fabric edges in a divergent manner, to the full open width condition of the fabric, the lateral tension of the fabric on the pins acts generally at right angles thereto, in the manner desired.

Once pivoted into an upright position, the pin carriers are secured by locking levers. During the remainder of the tenter conveying, the tenter pins function in a more or less conventional manner. However, as the pin carriers approach the discharge end of the tenter chains, the locking levers are engaged and displaced by releasing cams 47, causing the pin carriers to pivot back to their original positions, with the tenter pins projected inward in a generally horizontal disposition. The now full-width fabric is thus easily depinned, and the fabric is conveyed further in a conventional manner to a suitable windup or gathering facility.

One of the particularly important features of the present invention resides in the provision of means for controllably altering the angular orientation of the tenter pins during the operative cycle of the tenter chains, so that the tenter pins may at all times have an optimum orientation relative to the fabric. Most desirably, the controlled pin orientation is achieved by means of suitably contoured cam tracks disposed alongside at least portions of the tenter chains and arranged to effect controllable pivoting of the tenter pin carriers in accordance with the linear advancement of the tenter chains. Where the tenter chains are of significant overall length, it is further desirable to incorporate releasable locking means for holding the tenter pin carriers in a predetermined orientation initially effected by the cam tracks.

As will be readily appreciated, the use of tenter pin carriers which can be controllably oriented over the operative run of a tenter chain may have widespread application in processing tenters of all types. The controllably oriented pin carriers are, however, useful to particular advantage in a slitting and opening apparatus of the general type disclosed in the Sidney L. Carter, et al., U.S. Pat. No. 3,289,510, where fabric, initially in tubular form, is longitudinally slit, engaged by closely spaced pairs of tenter chains, and advanced divergently to convert the once-tubular fabric to a full, open width form. In such an apparatus, the optimum orientation of the tenter pins is generally horizontal during the initial pinning stage, generally vertical during the conversion stage (at least during the latter portions thereof), and generally horizontal again during the discharge or depinning stage. The arrangement of the invention, while being of an inherently simplified mechanical nature, readily accommodates these various optimum conditions, as will be readily understood.

Where the slitting and opening facility includes an integral or continuous processing tenter stage, with generally parallel sections of the tenter chains forming an uninterrupted continuation of the divergently related portions thereof, the controllably oriented tenter pin arrangements, are even more useful still. Thus, as will be understood, if it is desirable to utilize a processing stage, as for setting the fabric to width, drying, or otherwise controllably processing the fabric while retaining it uninterruptedly engaged by a pair of continuous tenter chains, it is particularly important to provide for the vertical disposition of the tenter pins, during at least the processing stages, where substantial widthwise tensions may be experienced.

It should be understood, of course, that the specific form of the invention herein illustrated and described, is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following appended claims in determining the full scope of invention.

* * * * *

Current U.S. Class:	83/151 ; 26/73; 26/82; 26/87; 26/89; 26/91; 26/96; 83/155; 83/175; 83/435
Current International Class:	D06C 3/00 (20060101); D06C 3/02 (20060101); D06H 7/08 (20060101); D06H 7/00 (20060101); D06c 003/02 ()
Field of Search:	83/151,155,175,425,435 242/56.2,62 26/1,55,61A,62A,62C