US3797080A

US3797080A - Apparatus and method for separating fabric sections

Info

Publication number: US3797080A
Application number: US00244050A
Authority: US
Inventors: M Rockman; A Cecere
Original assignee: Samcoe Holding Corp
Current assignee: Samcoe Holding Corp
Priority date: 1972-04-14
Filing date: 1972-04-14
Publication date: 1974-03-19
Anticipated expiration: 1991-03-19

Abstract

The invention relates to apparatus for separating connectedtogether sections of tubular knitted fabric, such as sweater bodies, for example. The apparatus includes a spreading frame, which engages the tubular fabric internally and arranges it in flat form. The tubular fabric is advanced by belts engaging the internal side edges of the frame. As the fabric sections are conveyed along the spreader frame, a draw thread or connecting thread is partially withdrawn and engaged by a rotating mandrel which serves forcibly to withdraw the connecting thread from the moving fabric, thus substantially separating a pair of adjacent fabric sections. The construction of this mandrel, to provide for high production, semi-automatic operation, is one of the features of the invention. After withdrawal of the connecting thread, adjacent fabric sections are connected together only by a ''''cord'''' of yarns, and a novel and improved arrangement is provided for severing this yarn cord on an automatic, high-speed basis. A new cutting means includes automatically fluctuated fingers which engage the yarn cord and carry it to a high-speed cutter. An additional feature of the invention is the method by which the successive fabric sections are handled and conveyed to assure proper location of the yarn cord for the automatic cutting operation.

Description

PATENTED HAR l 9 |974 SMU 1 9? 7 United States Patent i191 Rockman et al.

i451 Mar. 19, 1974 [54] APPARATUS AND METHOD FOR sEPARATlNG FABRIC SECTIONS [75] Inventors: Murray L. Rockman, Plainview;

Andrew P. Cecere, Valley Stream, both of N .Y.

[73] Assignee: Samcoe Holding Corporation,

Woodside, N Y.

[22] Filed: Apr. 14, 1972 [2l] Appl. No.: 244,050

2.926.416 3/1960 Feldstein et al. .i 28/17 3,163,912 l/l965 Loflen 28/17 3,166,261 l/l965 Loflen 28/17 X 3,298,077 l/1967 Russak 28/17 Primary Examiner- Robert R. Mackey Attorney, Agent, or Firm-Mandeville and Schweitzer [57] ABSTRACT The invention relates to apparatus for separating connected-together sections of tubular knitted fabric, such as sweater bodies, for example. The apparatus includes a spreading frame, which engages the tubular fabric internally and arranges it in flat form. The tubular fabric is advanced by belts engaging the internal side edges of the frame. As the fabric sections are conveyed along the spreader frame, a draw thread or connecting thread is partially withdrawn and engaged by a rotating mandrel which serves forcibly to withdraw the connecting thread from the moving fabric, thus substantially separating a pair of adjacent fabric sections. The construction of this mandrel, to provide for high production, semi-automatic operation, is one of the features of the invention.

After withdrawal Of the connecting thread, adjacent fabric sections are connected together only by a cord of yarns, and a novel and improved arrangement is provided for severing this yarn cord on an automatic, high-speed basis. A new cutting means includes automatically fluctuated fingers which engage the yarn cord and carry it to a high-speed cutter.

An additional feature of the invention is the method by which the successive fabric sections are handled and conveyed to assure proper location of the yarn cord for the automatic cutting operation.

10 Claims, 10 Drawing Figures PATENTE!) HAR 19 |914 SHEET 6 UF 7 FIG. 7

FIG. 8

APPARATUS AND METHOD FOR SEPARATING FABRIC SECTIONS BACKGROUND AND PRIOR ART ln the manufacture of sweater blanks and other relatively short sections of tubular knit fabric, it is conventional practice to knit a continuous length of connect- -edtogether sections to facilitate handling of the fabric during the various necessary preliminary processing operations. At some stage, of course, it becomes necessary to effect separation of the connected-together sections, to enable them to be incorporated into garments. To this end, the initial knitting construction of the fabric is carried out in a manner such that some of the yarns going into the structure of the fabric section are combined together and are transferred from one section to another in a single bundle or cord located at one point on the circumference of the fabric tube. A special withdrawable connecting thread is also incorporated in the fabric construction at this stage and serves temporarily to join adjacent fabric sections in order to maintain the lengthwise integrity of the knitted fabric tube.

After preliminary processing of the fabric has been completed, it is necessary to separate the individual fabric sections by withdrawing the connecting threads and severing the yarn cords. In some cases, this can be done by hand. However, for sustained production operations, it is, of course, advantageous to provide mechanical assistance and a degree of automation.

Earlier proposals for the mechanization of fabric section separation are reflected in the following U.S. Pats: Weller Pat. No. 2,422,154; Kastrinsky Pat. No. 2,779,084; Feldsten, et al., Pat. No. 2,926,416; Loflen Pat. No. 3,163,912 and Loflen Pat. No. 3,166,261. Rights to the before-mentioned Loflen patents are owned by the assignees of this application.

Principally, the Weller, Kastrinsky and Feldstein et al. patents are directed to arrangements for mechanically assisting the withdrawalof` the connecting thread. ln the Weller patent, for example, the thread is engaged by meshing gears and is thereby pulled from the fabric. ln the Kastrinsky patent, the connecting threads (conventionally forming loops at the edge of the fabric) are engaged by hooks on a rotatable mandrel, and the threads are withdrawn by rotation of a mandrel. ln the Feldstein et al., patent, a rotating mandrel is provided with a plurality of radial fingers for engagement of looped ends of the connecting threads, enabling the threads to be withdrawn by rotation of the mandrel. The Loflen 3,163,912 patent represented an important advance in the art by introducing an advantageous arrangement for holding the tubular fabric in flat form to facilitate automatic withdrawal of the connecting threads by a power-driven mandrel. The related Loflen 3,166,261 patent is directed to a special, frusto-conical form of mandrel.

SUMMARY OF THE INVENTION The present invention is directed to the general type of machine reflected in the above-described prior art patents, but incorporates a number of important improved features and improved principles of operation, providing for higher speed and more reliable operation, and an increased degree of automation of the overall operation. Thus, in accordance with one aspect of the invention, a novel and improved thread-pulling mandrel arrangement is provided which significantly facilitates the ability of the operator to apply the drawthread to the mandrel and thus enables the overall processing operation to be carried out at a higher rate of speed. In this respect, the apparatus includes a spreading frame for internally engaging the fabric tube, and the operator customarily stands at the upstream or entry end of the spreader frame and applies the fabric onto it in such manner that the yarn cord is generally aligned with one edge of the spreader frame. The rotating thread-pulling mandrel is, in accordance with the invention, arranged to extend alongside the spreader frame, substantially to the loading station, and is arranged so the operator can conveniently apply the end loop of the connecting thread over the free end of the mandrel. The design of the mandrel is such that, at the proper time, the connecting thread is automatically engaged for effecting withdrawal; the operator is not required separately to perform this task. To this end, the mandrel has an elongated, tapered entry portion at its upstream extremity, and an adjacent associated winding portion having means for automatically engaging vthe connecting thread loops as the fabric advances alongside the mandrel.

In accordance with another important aspect of the invention, the new apparatus includes a cutting knife arrangement at the discharge end of the spreadingconveying frame, arranged to engage and sever the yarn cord following withdrawal of the connecting thread. In order to assure reliable alignment of the yarn cord, the spreader frame is asymmetrically arranged, so that the side of the frame opposite the yarn cord, is shorter than the other side. Thus, as the laterally distended fabric reaches the discharge end of the frame, the entire lateral contraction of the knitted fabric will occur at the side opposite the yarn cords. Thereafter, as the fabric is discharged from the long side of the spreader frame, the yarn cord remains in its original alignment, providing maximum reliability in the cutting operation.

In accordance with another aspect of the invention, proper carrying out of the yarn cord cutting operation is facilitated by providing a conveyor blanket directly under the spreader frame, traveling at a slightly higher rate of speed than that at which the fabric is being conveyed over the frame itself. Thus, after withdrawal of the connecting thread, and particularly after discharge of the fabric from the short side of the frame, the fabric will tend to be advanced at an accelerated speed by the underlying blanket. The yarn cord, however, remains connected to the principal fabric body, traveling at a slower speed. As a result, a tapered gap is opened up between adjacent fabric sections, facilitating proper meeting of the cutting knife and yarn cord with minimized opportunity for the knife to damage any part of the basic fabric body. I

A further advantageous feature of the invention resides in the provision of a novel and highly effective cutting knife mechanism, including a pair of cyclically operated fingers arranged to engage the yarn cord, between otherwise separated fabric sections, and to lift the cord quickly into a high-speed cutting knife to complete the separating operation. The operation of these fingers is effected by an advantageous arrangement of photocell and light source, which detects a fabric edge forming one side of partially separated fabric sections and effects controlled actuation of the filtering fingers in precisely timed relationship to the location of the yarn cord at such gap.

The invention is also directed in important respects to new procedural or method'aspects of processing connected-together fabric sections to effect their efficient separation. Among these are the manner in which the fabric is handled during its conveyance, first being laterally distended and conveyed, then released at one side and conveyed at a somewhat higher speed, and then separated by yarn cord severance. This new procedure is both efficient and highly reliable, making it eminently suitable for high volume, production operations.

For a more complete understanding of the above and other advantageous features of the invention, reference should be made to the following detailed description and to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are top plan and side elevational views, respectively, of a fabric separating machine incorporating the principles of the invention.

FIG. 3 is an enlarged, fragmentary side elevational view of the apparatus of FIGS. 1 and 2, with parts broken away, to show details of an advantageous guide bar arrangement. l

FIG. 4 is an enlarged, fragmentary, cross-sectional view, taken generally on line 4-4 of FIG. 1.

FIG. 5 is an enlarged, fragmentary cross-sectional view taken generally along line 5--5 of FIG. 6, and illustrating details of a cutting knife arrangement and photocell control.

FIGS. 6, 7 and 8 are sequential views illustrating the operation of the cutting knife and lifting finger mechanism incorporated in the apparatus of FIGS. 1 and 2.

FIG. 9 is a simplified top plan view of the spreading and conveying frame of the apparatus of FIGS. l and 2, illustrating the manner of handling and separating connected-together tubular fabric sections according to the invention.

FIG. 10 is an enlarged cross sectional view taken along line 10-10 of FIG. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to the drawings, and initially to FIGS. 1 and 2 thereof, the reference numeral 10 designates generally a tubular length of knitted sweater body sections or the like 11. Typically, the sweater body sections 1 1 comprise body portions 12 and waistband portions 13. The tubular length 10 typically is knitted on a contiuous basis to form the body portion 12 and waistband 13 of one body section, and then to knit the bodyv and waistband portion of successive sections. Where the waistband portion 13 ofone section connects with the body portion 12 of a subsequent section, there is conventionally provided a connecting thread or draw thread (not shown in its entirety) which includes a looped portion 14, as shown in exaggerated form in broken lines in FIG. l. The looped portion enables the draw thread to be engaged and pulled from the otherwise continuous fabric tube, to effect partial separation of the successive sections.

In the continuous knitting of the connected-together sweater bodies, various of the yarns utilized in the construction of the fabric are, at the time of transition from the ending of construction of one section to the beginning of another, gathered together and transferred as a single cord of yarns, sometimes hereinafter referred to as the yam cord. Such a yarn cord is evident at 15 in FIG. 6, for example.

The above described technique for constructing connected-together sweater bodies is conventional, and the conventional sever yarn cord first procedure for separating the sections at the desired time consists of first severing the yarn cord 15 and then removing the connecting thread 14. The apparatus and method of the invention enables these operations to be carried out on a relatively high sPeed, automatic basis, enabling great savings in labor to be realized and overall production rates to be increased.

In the new apparatus, there is a basic frame structure 16 supporting on suitable transverse slide rods 17 a pair of edge drive roll carriages 18, 19 (the carriage 19 being shown in FIG. l with a protective cover). The near side carriage 19 is fixed while the carriage 18 is adjustable toward and away from the near side of the machine, by means of a transverse threaded shaft 20. Each of the carriages mounts an edge drive roll 21 arranged to be rotated by a square drive shaft 22.

The edge drive rolls 21 are circumferentially grooved to engage and support a width-adjustable spreaderpropeller frame, designated generally by the numeral 23. The spreader frame 23 includes a pair of longitudinally extending

frame members

24, 25 mounting a plurality of sheaves 26 carrying fabric engaging belts in a manner well-known per se. The

spreader frame sections

24, 25 are supported in adjustable spacing by a connecting element 27. The arrangement is such that, after the width of the spreader frame has been determined by adjustment of the connecting member 27, to suit the desired processing width of the tubular fabric 10, the spreader frame may be positioned between the spaced edge drive rolls 21 and the carriage 18 adjusted laterally to engage the spreader frame in the recessed portions of the edge drive rolls. In the area of engagement with the edge drive rolls, the spreader frame is recessed inwardly, as reflected in FIG. 1. Accordingly, the entire frame is effectively secured in position, both vertically and horizontally, by the rolls 2l.

The carriage 19 is fixed in position, to establish a fixed reference position for the near side frame section 2S of the spreader. The front or upstream end of the spreader frame is provided with a wire guide element 28 which facilitates the entry of the incoming fabric tube over the spreader frame. The guide 28 advantageously includes wire sections 28A connected by flexing spring sections 28 B to accomodate adjustment.

Extending underneath the back or downstreamportions of the spreader frame is a supporting conveyor blanket 29, carried by

transverse rolls

30, 31 joumaled in the machine frame, The width of the supporting blanket 29 is sufficient to accommodate the maximum width capacity of the equipment. At least one of the

rolls

30, 31 is driven, and in the illustrated arrangement the roll 31 is driven by means of a belt 32 connected to the drive shaft 22 for the edge drive rolls. To advantage, the driving relationship between the edge drive rolls 21 and the supporting blanket 29 is such thatthe speed of the blanket slightly exceeds the speed at which the fabric tube vis conveyed along `the spreaderpropeller frame by the edge drive rolls. The reason for thiswill become apparent hereinafter.

In thc illustrated apparatus, a single variable speed motor 33 (FIG. 2) may be utilized to control the principal driving functions of the equipment, principally the edge drive rolls 21 and the support blanket 29.

As shown particularly in FIG. 1, the supporting blanket 29 commences at a point somewhat downstream of the

edge drive carriages

18, 19 and extends at least slightly beyond the downstream or discharge end of the spreader frame, so that the fabric sections are supported and conveyed by the blanket 29 after being discharged from the frame. In addition, for reasons which will be made apparent, one side frame 24 of the spreader-propeller extends downstream at least a short distance beyond the terminal end of the other frame section 25. In a typical case, the frame section 24 might extend 6 inches or so beyond the end of the frame section 25. For purposes of reference, the side of the machine along which the longer frame section 24 extends will be referred to as the far side, whereas the side along which the frame section 25 extends may be considered the near side.

Mounted along the front side of the machine, generally at the level of the plane of the spreader frame 23, is a thread drawing mandrel, generally designated by the reference numeral 34. In accordance with one aspect of the invention, the draw mandrel 34 comprises a winding section 35 and a guiding section 36. The

' winding section 35 is of tubular, generally cylindrical form and is mounted by means of bearings 37, 38 (FIG. 4) on an elongated, longitudinally disposed shaft 39. The shaft 39 is mounted in cantilever fashion by means of bearing pillow blocks 40, 41, bolted to the machine frame and rotatable relative thereto. At its downstream end, the mandrel shaft 39 mounts a large diameter pulley 42 driven through a belt 43 by a small diameter pulley 44. The pulley 44 is driven from a motor 45 through a speed reduction system including a small diameter motor pulley 46, a large diameter pulley 47 and a shaft 48 on which the

pulleys

44, 47 are carried. The shaft 39 thus is driven through a double speed reduction system at a relatively low rotational speed relative to the motor 45.

A shaft 48 also mounts an additional pulley 49 of large diameter which drives a belt 50 engaged with a suitably grooved end portion of the winding section 35 of the mandrel. The grooved portion of the mandrel is` of relatively small diameter compared to the pulley 49, and thus is arranged to be driven at a relatively high rotational speed relative to that of the mandrel shaft 39. The motor 4S desirably has a variable speed control, enabling the mandrel to be operated at the minimum speed appropriate for the task.

Mounted on the upstream end of the Mandrel shaft 39 is the guiding section 36 of the mandrel. This is of elongated tapered configuration, extending sufficiently far in the upstream direction as to have its terminal end 51 adjacent the upstream end of the spreader frame 23. The arrangement of the machine is such that the upstream end of the mandrel is convenient to the operators station for the machine, at its front, upstream region. An operator stationed in this area can feed the incoming fabric tube l0 properly onto the spreader frame, and also has convenient access to a control switch housing 52 and a width control adjustment 53.

As reflected in FIG, 2, the guiding section 36 of the mandrel projects a substantial distance from the bear# ings 40, 4l mounting the mandrel shaft 39. Since the front or upstream end of the mandrel is unsupported, the rotation of the shaft 39, and the guiding section 36 of the mandrel is kept at a very low rate, to avoid excessive vibration and problems derived therefrom.

The arrangement of the guiding section 36 of the mandrel is such that, as successive fabric sections are drawn over the spreader-propeller frame 23, the operator can manually engage the draw thread loops 14 as they come along in succession and draw these loops outward a sufficient distance to apply them over the upstream end of the mandrel. Desirably, the upstream extremity is provided with an enlarged tip 54 forming a rearwardly facing shoulder 5S. Thus, when an operator pulls the draw thread over the front end of the mandrel, the thread is held momentarily from sliding back off the mandrel by the enlarged tip 54. Of course, during the normal operation of the equipment, the fabric tube is continuously traveling in a downstream direction, so that the draw thread is quickly carried toward the rear along the guiding portion of the mandrel. In this respect, the slow speed of rotation of the mandrel section 36 need be sufficient only to minimize the friction acting on the draw thread loops as the same are moved in a downstream direction along the mandrel.

As shown in FIGS. 2 and 4, the configuration of the guiding portion of the mandrel is such that the mandrel increases in diameter in the downstream direction. It is provided with a short skirt portion 56 at its downstream end which closely surrounds the upstream end of the winding section 35. Thus, as successive fabric sections are propelled along the spreading frame 23, the draw threads 14 applied over the mandrel are drawn along the guiding portion and are applied on the upstream end of the winding section 35. n

In accordance with one aspect of the invention, and as reflected particularly in FIG. 4, the upstream portion of the mandrel section 35 is provided with a plurality (typically four) of radially extending draw pins 57. The pins have outer portions S8 which extend at about a 45 angle to the access of the mandrel section 35, in an outward and upstream direction.

As successive fabric sections are conveyed along the spreader frame, the loops 14 of separating thread are advanced along the mandrel 34 up to a point where, as illustrated in FIG. 10, one of the draw pins 57 engages a portion of the separating thread, deflects the thread in a downstream direction, and thereby causes the thread loop to straddle at least one of the draw pins. The winding section 35 of the mandrel, which is rotating at high speed, thereupon snags the loop of the draw thread and quickly and forcibly withdraws it laterally from the fabric tube, which continues to advance in the downstream direction. The fabric sections are thereupon separated, except for the yarn cord connection which remains.

In accordance with the techniques employed in the practice of the invention, the operator guiding the fabric tube onto thespreader-propeller frame 23 does it in such a way as to align the fabric cord substantially with the far edge extremity of the flattened tube. Accordingly, after removal of the separating thread, the fabric sections are connected only along the far edge of the tube.

In the construction of the machine, ample clearance is provided about the winding section 35 of the mandrel, such that a large number of successive separating threads may be engaged and withdrawn from successively advancing connected fabric sections without stopping the machine. The threads occupy little space and a great number of them may be accumulated on the surface of the mandrel section 3S without requiring removal. Typically, this may have to be done only once or twice per shift.

In order that the mandrel guided thread loops properly clear the near side edge drive roll 21 (see FIG. 3), one or more guide bars 59-62 are mounted on the machine frame. The bars 59-61 overlie the top of the near side edge drive roll and serve to deflect the advancing draw threads upwardly and over the top of the roll. In addition, depending on the nature of the fabric being processed, the resistance of the separating threads to being laterally withdrawn occasionally may be so great as to actually tend to draw the fabric itself` laterally toward the mandrel. To prevent this happening to an excessive extent, one of the lower guide bars 61 extends in parallel relation alongside the winding section 35 of the mandrel and cooperates with an upper guide bar 62 spaced slightly above and disposed parallel to the guide bar 61. The upstream end portion 63 of the guide bar 62 extends upwardly at an angle and forms an enlarged entrance opening to facilitate guiding the thread into the narrow, horizontal slot 64 formed between the parallel portions of the guide bars 61, 62. As evident in FIG. 3, the slot 64 extends from a point near the draw pins 57 in a downstream direction, for a distance sufficient under normal operating conditions to assure complete withdrawal of the thread. The width of the slot 64 is such as to easily accomodate the separating thread while preventing passage therethrough of the fabric itself in cases of extreme resistance to separating thread withdrawal. The

bars

61, 62 also confine the direction of pull of the separating threads substantially to the plane of the flattened tube.

As reflected in FIG. 9, the initial adjustment of the spreader-propeller frame 23 is such that the fabric l0 is laterally distended to at least some degree as it passes over theV frame. This assures that the fabric is maintained in flat, wrinkle-free condition and engages the frame with sufficient force to accomodate the necessary handling and control. As the fabrictravels along the spreader frame, the draw threads are successively engaged bythe draw pins 57. The reference numeral 65 in FIG. 9 reflects the partial withdrawal of a separating thread between

fabric sections

66, 67. Slightly farther downstream along the spreader frame, complete withdrawal of the separating thread has been effected between

fabric sections

67, 68, although these sections remain attached in the region indicated by the reference numeral 69, by reason of the still-intact yarn cord l5.

' As the fabric continues to travel downstream on the spreader frame, the near edge of the fabric will be discharged from the near edge extremity 70 of the spreader frame, causing the laterally distended fabric to contract widthwise to its relaxed width dimension. In this respect, it is a feature of the invention that, by reason of the discharge end 70 of the near frame section being located upstream of the discharge end 71 of the far frame section, the entire widthwise contraction of the fabric will occur at the near edge thereof.l When the fabric an instant later, is discharged from the far side of the frame, it is fully relaxed and has little or no tendency to contract further. This enables the far edge 72 of the fabric to be kept in a predetermined aligned relationship as initially established by the spreader frame itself to facilitate automatic severance of the yarn cord as will appear.

As reflected in FIG. 2, for example, the supporting blanket 29 is disposed directly underneath the discharge end portion of the spreading frame, in a position to receive and support the fabric sections as they are discharged from the spreader. Thus, as particularly reflected in FIG. 9, when a fabric section 73 is discharged from the near side of the spreader frame, it is immediately supported by the blanket 29 and conveyed along at the speed of the blanket, which is slightly faster than that of the spreading frame. Since the fabric section remains attached by the yarn cord 15, at the far edge extremity, it therefore cannot travel at a faster rate of speed than the fabric being advanced over the propeller-spreader 29. The remainder of the fabric, however, is tending to be advanced more rapidly, at the speed of the supporting blanket 29, and this causes a converging gap 74 to open between the

successive fabric sections

72, 73. This gap, being wide at the near edge of the fabric and diminishing toward the far edge, greatly facilitates the severance of the yarn cord 15 and thereby the ultimate separation of the fabric section 73 from the oncoming material.

In accordance with one aspect of the invention, a novel and advantageous form of cutting facility is provided to permit the automatic, accurate severance of a yarn cord 15 between successive blanks without, in turn, damaging the sweater blanks. The cutting facility shown in detail in FIGS. 5-8, includes both a cutting means and an automatic detecting means for precisely timing the actuation of the cutting means. The timing means (see FIG. 6) includes a specially arranged light source and a photocell 81 mounted on a bracket 82 secured to a laterally adjustable cutter carriage 83. The cutter carriage 83 is mounted for transverse movement on a pair of spaced supporting

shafts

84, 85 and is controlled as to its position by means of a transverse threaded shaft 86. As reflected in FIG. l, the transverse threaded shaft 86 is connected by a chain 87 and suitable sprockets to the threaded control shaft 20 for the

edge roll carriages

18, 19. Accordingly, the cutter carriage 83, supporting a cutting knife 88 and related mechanism to be described, as well as the photocell control bracket 83, is laterally adjustable along with the far edge drive carriage 18, so as to be kept at all times in a predetermined alignment relationship with the far spreader frame section 24. l

In the illustrated apparatus, an elongated thin metal blade 89 is secured to the far edge drive carriage 18 and extends downstream therefrom, resting on the upper surface of the supporting blanket 29. The length of the blade 89 is such that its downstream extremity generally underlies the plane of the cutting knife 88.v

The end area of the blade is provided with a reflecting area 90, which may comprise a section of reflective material. n

Normally, the reflecting area 90 is covered by the moving fabric being conveyed by the blanket 29. However, when the tapered gap 74 between partially separated fabric sections, from which the draw thread has been removed, passes over the reflecting area the photocell 8l is activated to a standby condition. When the edge of the oncoming fabric section (i.e., the upstream edge ofthe gap 74), passes under the light beam and greatly reduces the amount of reflected light reaching the photocell 81. The deactivation of the photocell 81 initiates the cutting sequence described below.

With reference particularly to FIGS. -8, the cutter carriage 83 is shown to mount a motor 97 driving, through a pair of

pulleys

98, 99 and a belt 100, a high speed rotary cutting knifev 88. The cutting knife 88 is journaled by suitable carriage brackets 102 and is contained in a protective housing 103. As reflected particularly in FIG. 6, the axis of the cutting knife is mounted in fixed relation to the carriage 83, so that is lower edge is slightly above and to the rear of the normal position of the yarn cord 15. As will be described, cutting of the yarn cord is effected by causing the cord to be picked up and carried into the rotating knife blade, rather than moving the knife blade toward the yarn cord. Additionally, in this respect, the

side plates

104, 105 of the knife guard 103 are of sufficient radial dimension to completely enclose the cutting knife 88, but are spaced sufficiently far apart as to permit the pliable yarn cord to be carried into the housing sufficiently far to engage the cutter.

Lifting of the yarn cord into the cutter is effected by a pair of pickup fingers 106, which are disposed in straddling relation to the plane of the cutting knife 88 and are pivotally connected at 107 to the end of a lifting lever 108. The lever 108 is, in turn, pivotally connected at 109 to a crank arm 110 carried by a rotary shaft lll journaled in the cutter carriage. The lifting lever 108 is also pivotally supported, at allocation 112 to a rocker arm 113, which is pivoted at 114 in a bracket 115 suspended from the cutter carriage.

Normally, the pickup fingers 106 and lifting lever 108 are held in a predetermined geometrical relationship, as shown in FIGS. 6 and 8. This is realized by providing a suitable adjustable stop bolt 116 positioned to act upon upper end portions 117 of the pickup fingers, in conjunction with extendable springs 118. As viewed in FIG. 8, for example, the springs 1 18 tend to pivot the pickup fingers in a clockwise direction, to bring the upper end extremities 117 into Contact with the stop bolt means 116. The pickup fingers may, however, be pivoted in a counterclockwise direction, relative to the lifting lever 108, against the action of the springs 118, as is reflected in FIG. 7, for example.

A typical sequence of operation of the pickup fingers 106 is reflected in the sequential views of FIGS. 6, 7 and 8. In FIG. 6, for example, the crank arm 110 is shown in a rest or start position, disposed generally in alignment with the lifting lever 108 and pickup fingers 106, but extending generally in the opposite direction. In this configuration of the mechanism, the pickup fingers 106 are in a position of maximum retraction from the surface of the supporting blanket 29. Upon clockwise rotation of the shaft 1 11 and crank arm 110 to the position shown in FIG. 7, the pivot point 109 for the lifting lever 108 has been advanced downward and toward the far side. This causes the lever 108, whose outer end is confined by the rocker arm 113, to be moved in a downward direction and toward the far side, and also to be rotationally reoriented in a clockwise direction. As reflected in FIG. 7, the geometry of the elements is such that, in this configuration, the lower extremities 119 of the pickup fingers, which are desirably flattened and bent upwards somewhat, are pressed into contact with the upper surface of the supporting blanket 29. This contact is established prior to the mechanism reaching the configuration shown in FIG. 7, whereupon the tips 119 of the pickup fingers remain pressed against the blanket 29, and continued movement of the lifting levers 108 is accommodated by extension of the springs 1 18 and pivoting of the fingers at 107.

Continued clockwise rotation of the shaft 111 and crank arm 110 to the configuration shown in FIG. 8 causes the pivot point 112, connecting the rocker arm 113 to the lifting lever 108, to be advanced in an arc, in a downward direction and toward the far side. This causes the tips 119 of the lifting fingers to be advanced toward the far side along the surface of the blanket, while being urged lightly against the surface of the blanket by the extended springs 118.y Eventually, the pickup fingers slide underneath the yarn cord 15 and, with continued movement, the yarn cord becomes engaged by stop pins 120 extending upward from the pickup fingers.

By the time the mechanism has reached the position of FIG. 8, the lifting lever 108 has been rotationally reoriented in a counter-clockwise direction and has caused the pickup fingers 106 to be lifted off the surface of the supporting blanket 29 and carried to the cutter housing 103. As is apparent in FIG. 5, the tips of the pickup fingers 106 are received in the lateral clearance spaces between the cutter blade 88 and the

housing walls

104, 105.

A yarn cord l5 engaged by the pickup fingers 106 and the stop pins 120 will be carried into and beyond the outer edge extremity of the cutting blade 88 (See FIG. 8) and thus will be reliably severed, allowing the now separated fabric section 73`to be conveyed away at an accelerated speed by the supporting blanket 29 and permitting the next successive sweater blank to resume its normal advancement. Continued clockwise rotation of the shaft 111 and crank arm 110 results in a retraction of the lifting lever 108 and rocker arm 113 and an eventual return to the condition of the vapparatus reflected in FIG. 6.

To effect proper, timed actuation of the crank arm 110, there is provided a single revolution clutch 121 driven by a belt 122 from a pulley 123. The pulley 123 is, in turn, driven from a shaft 124 mounting the cutter blade 88. The belt 122 is driven continuously by the pulley 123 and, upon appropriate signal from the photocell control -82, the single revolution clutch is actuated to cause the crank arm to be advanced at high speed through a single revolution, starting and finishing generally in the position shown in FIG. 6.

SUMMARY OF OPERATION AND ADVANTAGES In the normal operation of the apparatus of the invention, a machine operator is typically stationed in the region of the front or upstream end, at the near side of the machine. A more or less continuous length of connected-together tubular fabric sections is drawn by the operator from a suitable supply (not shown), oriented to align the yarn cord 15 with the far edge of the spreader-propeller frame, and applied over the front end of the frame. The width of the frame is adjusted, along with the postioning of the far side edge drive roll 21, to impart a slight width-wise distention to the fabric and to cause it to be advanced along the frame by engagement with internal belts.v As successive connecting threads 14 appear at the upstream end ofthe frame, the operator engages the draw thread loops 14 and pulls them laterally outward and somewhat in a downstream direction over the shouldered tip 54 of the mandrel guide section 36.

As the sweater sections are advanced along the propeller frame, the draw thread loops are guided along the mandrel section 36, onto a winding section 35. There, the successive loops are engaged by the draw pins 57 rotating at a suitably adjusted high speed with the winding section 35 of the mandrel, and the draw threads are quickly and forcibly withdrawn from the fabric to partially separate successive sections. The guide bars 59-63 assure proper control over the draw threads prior to the actual withdrawal operation, and, moreover, serve to prevent possible engagement between the draw pins 57 and the fabric sections themselves, in the case of severe resistance to removal of the draw thread.

After removal of the draw thread, the fabric sections continue along on the spreader-propeller frame until dropped off of the near side bar of the spreader onto the surface of conveyor blanket 29 and permitted to contract laterally to a relaxed condition, with all ofthe contractions occurring from the near side toward the farside. Since the fabric section is advancing at a more rapid rate on the conveyor blanket 29 than on the spreader-propeller frame, a converging gap 74 is opened up between fabric sections in the vicinity of the cutter. The upstream edge of this gap is detected by the photocell control 80,-81, causing the pickup fingers 106 to be actuated to engage the exposed yarn cord 15 and lift it into the rapidly rotating cutter 88. lnthis connection, the tapered configuration of the gap between adjacent sweater blanks facilitates movement of the pickup fingers 106 into a proper relationship with the yarn cord l and accurate guidance of the fabric, for effecting precise cutoff.

The method and apparatus of the invention greatly expediate the separation of successive, connectedtogether fabric sections from a continuous length of tubular knitted fabric and significantly reduce .the manpower requirements for this operation. In general, the production may be carried out on a high speed, substantially continuous basis, by means of a single operator, whose primary responsibility is to properly align the incoming tube of fabric and to initially apply the draw thread loop over the upstream end of the mandrei.

A feature of particular significance is the manner in which the fabric is handled and controlled after removal of the draw threads, enabling the remaining yarn cord to be severed on an entirely automatic basis, without further operator intervention. ln this respect, the mounting of the pickup fingers 106 is such that the tips 119 thereof are lowered into lightly pressing engagement with the surface of the conveyor blanket 29 and caused to slide laterally along the surface of the Vblanket, against the force of the extended springs 118, so as to reiiably slide underneath the yarn cord 15. Further, the manipulation of the fabric sections to form a converging gap toward the yarn cord facilitates proper initial lowering of the pickup fingers into the open gap, without lcontacting the surface of the fabric itself through minor mis-alignment. Thereafter, by reason of the pressure of the fingers against the conveyor blanket 29, at least a limited degree of self-alignment of the fabric with respect to the pickup fingers is provided for, assuring precise positioning of the yarn cord at the moment of cutting. i

The winding mandrel arrangement incorporated in the new apparatus is advantageous in that its twosection, two-speed construction permits the mandrel to extend from a cantilever mounting, near the downstream end of the machine, over a significantly long unsupported distance, such that the free and extremity of the mandrel is positioned adjacent the upstream end of i the spreader frame, at a convenient location for the operator. This enables the operator, stationed to orient and apply the incoming fabric over the spreaderpropeller frame, also to conveniently engage the draw thread loops and apply them successively over the tip of the mandrel. The upstream or guiding section of the mandrel is supported for rotation at as low a speed as practicable, consistent with the need to minimize sliding friction of the bar thread loop and permit the loop to advance along the length of the mandrel as the fabric is conveyed along the spreader-propeller frame. The winding portion of the mandrel, on the other hand, is arranged to be driven at a higher rotational speed, to effect removal of the draw thread as it travels along the length of the drawing station.

To enable automatic severance of the yarn cord to be accomplished on a reliable high speed production basis, the propeller-spreader frame is of an asymmetrical configuration, with the near side of the frame being effectively shorter than the far side. The laterally distended fabric sections being advanced along the spreader frame are discharged from the near side thereof slightly in advance of the far side. As a result, the lateral relaxation of the fabric is derived entirely by contraction of its near edge toward its far edge, while the far edge remains guided by the far section of the spreader frame. Thus, the yarn cord, aligned with the far edge of the frame, retains-its predetermined longitudinal alignment with the cutting apparatus, so that the eventual cut-off operation may be carried out in a reliable and precise manner. In addition, by providing for the conveyor blanket 29 to be operated at a slightly higher rate of speed than the propeller-spreader frame, the fabric sections supported by the blanket will tend to accelerate slightly as they are discharged from the spreader frame. However, since the sections remain attached at the yarn cord prior to severance thereof, such tendency to accelerate serves to open up a tapered gap, converging toward the yarn cord. This facilitates and renders more reliable not only the photocell-actuated triggering of the cut-off operation, but also the mechanical operations involved in the cut-off.

It will be understood, of course, that the specific form of the invention herein illustrated and described is intended to be representative only, as many 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 the invention.

We claim:

1. In a thread-pulling machine for separating connected sections of knitted fabric and which includes means for advancing fabric and a rotating threadpulling mandrel disposed alongside the advancing means, the improvement in said thread-pulling mandrel characterized by a. said mandrel having its axis disposed generally parallel to the axis of the advancing means,

b. said mandrel being of elongated form and having an elongated, tapered entry portion at its upstream lend and a thread winding portion at its downstream end,

c. the tapered entry portion being adapted to receive a loop of pulling thread and accommodating the movement of the loop along the entry portion of the mandrel as the fabric is conveyed by the advancing means,

d. the winding portion of said mandrel having means to engage the loop of thread and draw it laterally from the fabric.

2. The thread-pulling machine of claim 1, further characterized by a. the tapered entry end of said mandrel having an enlarged tip forming a retaining shoulder for retaining a loop of pull thread against movement in the upstream direction.

3. The thread-pulling machine of claim 1, further characterized by a. means journaling the entry and winding portions of said mandrel for independent rotation,

b. means for rotating said entry portion at relatively slow speed, and

c. means for rotating the winding portion at relatively higher speed.

4. The thread-pulling machine of claim 3, further characterized by a. said mandrel being mounted in cantilever manner at its downstream end,

b. a drive shaft being mounted for rotation, extending in an upstream direction through the winding portion of the mandrel and supporting and drivingly engaging the entry portion of the mandrel,

c. bearing means on said drive shaft supporting said winding portion for independent rotation relative to the shaft, and

d. means for driving the shaft and the winding portion of the mandrel at relatively lower and relatively higher respective rotational speeds.

5. The thread-pulling machine of claim 4, further characterized by a. the downstream end of the entry portion of the mandrel having an axially extending flange surrounding in telescoped relation the upstream end extremity of the winding portion.

6. The thread-pulling machine of claim l, further characterized by a. the loop-engaging means of the winding portion comprising one or more loop-engaging pins mounted adjacent the upstream end of the winding portion,

b. said pins extending radially outward and in an upstream direction.

. 7. The thread-pulling machine of claim 6, further characterized by a. said loop-engaging pins having outer extremities inclined outward and upstream relative to the axis of the winding portion.

8. A thread-pulling machine for separating connected sections of tubular knitted fabric, which comprises a. a spreading frame for supporting and guiding the tubular knitted fabric in flat form,

b. means for advancing the fabric along the spreading frame,

c. a thread-pulling mandrel disposed alongside the spreading frame in generally parallel relation, and

d. means forming a longitudinally extending guide slot between the spreading frame and the mandrel,

e. said slot being of sufficient width to receive a pulling thread while preventing passage in a lateral direction of portions of a fabric section.

9. The thread-pulling machine of claim 8, further characterized by a. said guide slot being formed by a pair of longitudinally extending guide rails mounted in closely spaced relation.

10. The thread-pulling machine of claim 9, further characterized by a. said spreading frame including fabric propelling belts along its lateral edges,

b. edge drive rolls being provided for supporting the spreader frame and having driving relation with said belts, and

c. at least the lower one of said guide rails having an upwardly offset section extending over the edge drive roll adjacent thereto, for guiding .the pulling threads over said edge drive roll.

Claims

1. In a thread-pulling machine for separating connected sections of knitted fabric and which includes means for advancing fabric and a rotating thread-pulling mandrel disposed alongside the advancing means, the improvement in said thread-pulling mandrel characterized by a. said mandrel having its axis disposed generally parallel to the axis of the advancing means, b. said mandrel being of elongated form and having an elongated, tapered entry portion at its upstream end and a thread winding portion at its downstream end, c. the tapered entry portion being adapted to receive a loop of pulling thread and accommodating the movement of the loop along the entry portion of the mandrel as the fabric is conveyed by the advancing means, d. the winding portion of said mandrel having means to engage the loop of thread aNd draw it laterally from the fabric.

3. The thread-pulling machine of claim 1, further characterized by a. means journaling the entry and winding portions of said mandrel for independent rotation, b. means for rotating said entry portion at relatively slow speed, and c. means for rotating the winding portion at relatively higher speed.

4. The thread-pulling machine of claim 3, further characterized by a. said mandrel being mounted in cantilever manner at its downstream end, b. a drive shaft being mounted for rotation, extending in an upstream direction through the winding portion of the mandrel and supporting and drivingly engaging the entry portion of the mandrel, c. bearing means on said drive shaft supporting said winding portion for independent rotation relative to the shaft, and d. means for driving the shaft and the winding portion of the mandrel at relatively lower and relatively higher respective rotational speeds.

6. The thread-pulling machine of claim 1, further characterized by a. the loop-engaging means of the winding portion comprising one or more loop-engaging pins mounted adjacent the upstream end of the winding portion, b. said pins extending radially outward and in an upstream direction.

7. The thread-pulling machine of claim 6, further characterized by a. said loop-engaging pins having outer extremities inclined outward and upstream relative to the axis of the winding portion.

8. A thread-pulling machine for separating connected sections of tubular knitted fabric, which comprises a. a spreading frame for supporting and guiding the tubular knitted fabric in flat form, b. means for advancing the fabric along the spreading frame, c. a thread-pulling mandrel disposed alongside the spreading frame in generally parallel relation, and d. means forming a longitudinally extending guide slot between the spreading frame and the mandrel, e. said slot being of sufficient width to receive a pulling thread while preventing passage in a lateral direction of portions of a fabric section.

10. The thread-pulling machine of claim 9, further characterized by a. said spreading frame including fabric propelling belts along its lateral edges, b. edge drive rolls being provided for supporting the spreader frame and having driving relation with said belts, and c. at least the lower one of said guide rails having an upwardly offset section extending over the edge drive roll adjacent thereto, for guiding the pulling threads over said edge drive roll.