Apparatus and method for severing textile fabric
United States Patent 11 1 Lee, Jr. et a1.  
 1 1 APPARATUS AND METHOD FOR SEVERING TEXTILE FABRIC [75] Inventors: Charles D. Lee. Jr.: James H.  
 Henderlite, 111. both of Charlotte.  
 [73] Assignee: Parks-Cramer Company. Fitchburg.  
 Mass.  
 [221 Filed: Aug. 21. I973 1211 Appl. No: 389.034  
 Related US. Application Data 163] Continuzttiotrixt-part of Scr. No. 283.165. Aug, 23.  
 I972. abandoned.  
 [ 1 Apr. 29, 1975 3.135.298 6/1964 Marles 139/302 3.144.882 8/1964 Steinem... 139/291 C 3.174.515 3/1965 Luber 139/291 C 3.414.955 12/1968 Courtney et a1. 28/19 3.461.920 8/1969 Sakamoto .J 139/302 FOREIGN PATENTS OR APPLICATIONS 10.771 4/1970 Japan 139/302 Primary E.\&#39;aminerHenry S. .laudon Attorney. Agent. or FirmParrott. Bell. Seltzer, Park &amp; Gibson [57] ABSTRACT Textile fabric is severed by the impingement there against of a heated fluid stream. preferably compressed air heated to a temperature at least sufficient to soften thermoplastic yarns forming a portion of the fabric and impinged against the yarns at a velocity at least sufficient to separate the softened yarns. and the fabric being maintained in a tensioned condition and supported adjacent the location of impingement.  
 4 Claims. 5 Drawing Figures cuuM OUBCE PATENIED Z E 3,880,201  
 sum 1 a? 2 ELEACTEJ CAL A SouIacE V CUUM ouBcE- APPARATUS AND METHOD FOR SEVERING TEXTILE FABRIC This application is a continuation-in-part of copending application Ser. No. 283,l65, filed Aug. 23, 1972, entitled SHUTTLELESS TEXTILE LOOM YARN SEVERING APPARATUS AND METHOD and now abandoned.  
  As is well known to persons familiar with the formation of textile fabrics, conventional textile looms which employ shuttles for inserting weft yarns into filling yarns produce a smooth fabric edge known as a selvage. Similar fabric edges are produced by appropriate manipulation of yarns being formed into fabrics by knitting. More recently developed textile fabric forming machines, and particularly certain shuttleless looms which insert weft yarns in a different manner, produce fabric which has a fringed or rough appearing edge along one longitudinal side edge.  
  As such fabric forming apparatus have grown in commercial acceptance, efforts have been made to develop arrangements and methods for producing a smooth longitudinal side edge along the fabrics produced. Sharp blades or knives have been mounted for cutting or trimming inserted yarns. Proposals have been made to use heated elements, typically in the form of an electrical resistance wire through which current is passed to cause the wire to become sufficiently hot to sever thermoplastic yarns and known as hot wires.  
  Both of these prior approaches suffer from difficulties and shortcomings. In the case of a blade or knife, the sharpened edge rapidly becomes dull and inefficient. Hot wires are relatively fragile and are subject to becoming broken. In addition, hot wires accumulate deposits of softened textile material and become thermally insulated, thereby losing efficiency.  
  Similar difficulties and deficiencies have been encountered in those instances where it has heretofore been proposed that fabric be severed at some widthwise intermediate location. By so severing fabric, a relatively wide apparatus may be employed to produce two or more widths of fabric narrower than the maximum width available for the particular apparatus.  
  The present invention overcomes the difficulties and deficiencies encountered by such prior arrangements, and additionally provides other advantages and benefits, by severing textile fabric with high velocity impingement of a heated fluid. Such severance of textile fabrics proceeds irrespective of whether the fabric is composed of yarns which are fully thermoplastic in nature, blended thermoplastic and natural fiber, or wholly natural fiber. As will be understood, the high velocity heated fluid stream is not subject to becoming dulled and does not accumulate deposits of textile material so as to loose efficiency.  
  Accordingly, it is an object of this invention to sever textile fabric by directing a flowing stream of pressurized fluid to be heated and to be impinged against the fabric. Delivery of the flowing stream of pressurized fluid is preferably accomplished by delivery of compressed air through an appropriate heater. The compressed air, on contacting of the textile fabric, is to be at a temperature at least sufficient to soften any thermoplastic content of yarns forming the fabric and be moving at a velocity at least sufficient to separate the softened yarns.  
  A further object of this invention is the formation of a smooth edge along a fabric by the severance of yarns forming the fabric through high velocity impingement of the heated fluid stream thereagainst. In accomplishing this object of the present invention, particularly where thermoplastic or partially thermoplastic yarns are used, a sealed edge having ravel resistance characteristics is obtained by the softening and adhesion of the yarns in accordance with the method of the invention.  
  Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is a perspective view of one textile fabric forming apparatus incorporating a fabric severing means in accordance with this invention;  
  FIG. 2 is an enlarged plan view of a portion of the apparatus of FIG. 1, illustrating the apparatus of this invention;  
  FIG. 3 is an elevation view, partially in section, taken generally along the line 33 in FIG. 2;  
  FIG. 4 is an elevation view, partially in section, taken generally along the line 4-4 in FIG. 2; and  
  FIG. 5 is an enlarged fragmentary view, partially in section, taken generally along the line 55 in FIG. 4.  
  This invention will be described hereinafter with particular reference to the accompanying drawings. It is, however, to be understood at the outset of this disclosure that the drawings and the description which follows are intended as a broad and general teaching of the apparatus and method of this invention and it is contemplated that various changes in the detailed structure disclosed may be made within the scope of this invention. Accordingly, the drawings and description are to be taken as illustrative only and not as limiting on this invention.  
  The accompanying drawings illustrate the anticipation that this invention is useful with a textile loom (generally indicated at 10 in FIG. 1) of the shuttleless type in which textile fabric is formed by the delivery of warp yarns by warp handling instrumentalities and the insertion of weft yarns into the warp yarns by weft yarn carrier instrumentalities. One conventional type of shuttleless textile weaving machine to which this invention has been applied is the Draper DSL machine commercially available in the United States from the Draper Division of Rockwell International. It is believed that machines of this type are generally known to persons working in the textile industry and, for that reason, detailed description of the DSL apparatus and its operating instrumentalities will not be given here. For the same reason, illustration and description of the application of this invention to a knitting machine, tenter frame and other fabric producing or handling apparatus, will not be given here, as it is contemplated that persons familiar with such apparatus and learning of this invention from this description will be enabled to incorporate this invention into such apparatus.  
  Fabric F produced on the loom 10 moves from the fell at which warp and weft yarns are interwoven toward a breast beam 11 of the loom, with a side edge portion of the fabric engaging the temples 12 (FIG. 2). Adjacent the breast beam 11, the fabric is passed about a take-off or sand roll 14, which maintains the fabric in tension and aligned with a predetermined path of travel (FIG. 3). As will be pointed out more fully hereinafter it is an important feature of this invention that the fabric be tensioned and guided along a predetermined path of travel.  
  In accordance with the present invention, the loom has mounted thereon means for severing the fabric F adjacent a longitudinal side edge thereof. The severing means, generally indicated at 15, directs a heated fluid stream to impinge against the fabric at high velocity, so as to sever the fabric as described more fully hereinafter.  
  In the form illustrated, the pressurized fluid employed is a compressed gas and particularly, compressed air. Air was chosen for use in an operating embodiment from which the present drawings were taken due to the usual availability of compressed air in textile mills. The air is delivered to the severing means through a conduit 16 which is suitably connected with an appropriate source (as schematically illustrated in FIG. 1).  
  In the form illustrated, the severing means 15 includes a thermally insulating casing 18 within which is positioned an electrical resistance fluid heater l9 having resistance wires 20 about which compressed air is directed to flow (FIGS. 4 and 5). Electrical current is supplied to the resistance wires 20 through suitable conductors 21, 22 from a suitable source (schematically illustrated in FIG. 1). As was the case with the selection of compressed air delivered from an appropriate source, selection of an electrical resistance heater means was influenced by the usual availability of electrical current in textile mills.&#39;Other gases or heaters may, of course, be adapted to the present invention.  
  Heated compresed air passing from the electrical heater 19 is directed, by an outlet conduit 24, toward the predetermined path in which the fabric F is guided and against a portion of the fabric which is under tension. It is to be noted that, in accordance with an important feature of this invention, the location of impingement is spaced inwardly from a side edge of the fabric (FIG. 2). In the specific arrangement illustrated, the heated air flow is directed to impinge upon the fabric F at 90 to the path of movement thereof (FIGS. 3 and 4). At the location of impingement, the fabric F passes above an underlying support plate 25, which has an opening therethrough for passage of the air stream. Inasmuch as the fabric is tensioned along its predetermined path of travel, guided along that path and supported by the plate 25, the impingement of the heated air stream severs the yarns of the fabric F. Particularly in instances where the yarns of the fabric are predominantly or wholly thermoplastic materials, softening of these yarns assures production of a ravel resistant edge along the resulting longitudinal side edge of the fabric F.  
  In the illustrated arrangement, the support plate 25 and the casing 18 of the severing means 15 are maintained in operative position by a mounting bracket 26 secured to the breast beam 11 of the loom 10 by appropriate fastener means.  
  Experimentation with apparatus as described hereinabove and illustrated in the accompanying drawings has shown that satisfactory operation will be obtained over a range of temperatures and a range of velocities. While more specific examples will be given hereinafter, it has been noted that operation in accordance with the present invention will occur where the temperature to which the air is heated is at least sufficient to soften any thermoplastic content of the yarns of the fabric. Reference to generally available descriptions of thermoplastic textile materials will show that polyesters typically soften in a range of from about 445 to 470 Fahrenheit and will melt at temperatures in the range of from about 470 to 550 Fahrenheit. Nylon will soften in a range below 550 Fahrenheit. Polypropylene will soften in a range of from about 275 to about 330 Fahrenheit and will melt in a range of from about 320 to 350 Fahrenheit. These temperature ranges may be considered as representing ranges in which operation in accordance with the present invention will occur and have been contemplated as operative with blends of thermoplastic and natural fiber and with natural fiber alone. Early experimentation with arrangements as contemplated by the present invention obtained satisfactory operation with such a range of fabrics at temperatures of at least about l,000 Fahrenheit. Typically, where an electrical resistance heater such as the heater 19 is employed, the application of voltages on the order of 40 to volts to a heater rated at 500 watts when operated at 110 volts will achieve the necessary temperatures.  
  As to velocities of flow, early experimentation with apparatus as described and illustrated here suggested that operation should be at a velocity of at least about 8,000 feet per minute. Subsequent experimentation revealed a correlation between the pressure, in pounds per square inch, at which air was supplied; the temperature to which the air was heated; and the velocity at which the air was delivered through an orifice having a diameter of about 0.055 inch. By way of example, the delivery of air at a pressure of about 1.5 psi and without heating resulted in a velocity of about 5,500 feet per minute. With application of approximately 35 volts, the air was heated to a temperature of approximately 450 and the velocity was found to be approximately 7,500 feet per minute. At a pressure of approximately 4 psi, the unheated velocity was approximately l0,000 feet per minute. With the application of approximately 55 volts the air was heated to a temperature of approximately 520 Fahrenheit and the velocity was increased to about 12,500 feet per minute.  
  One example of a material which has been satisfactorily severed in accordance with this invention, while being formed, is a relatively light weight shirting constructed with a plain weave having 44 warp ends per inch and 40 picks per inch. In the specimen fabric, both warp and filling yarns were a 250 denier zero twist bright polyester. Satisfactory cutting was achieved, with this relatively light weight fabric, at an air pressure of about 0.5 psi and a voltage of about 50 volts.  
  Another example of a fabric satisfactorily severed in accordance with this invention was a 10 ounce chambrey having filling yarns of percent cotton and warp yarns of 65 percent polyester and 35 percent cotton. A limited number of 100 percent polyester warp yarns were introduced at one side edge and medially of the width of the fabric, in order to provide for assured sealing of side edges to be produced in accordance with this invention. Satisfactory severing was achieved at air pressures of approximately 4 pounds per square inch and applied voltages on the order of 50 volts.  
  In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.  
 That which is claimed is:  
  l. A method of severing a length of textile fabric comprising the steps of moving fabric along a predetermined path of travel while imposing on the fabric forces tensioning the fabric in the plane of the path and while contacting one face of the fabric to restrain the fabric against movement in one direction transversely away from the plane of the path, delivering a flowing stream of gas while heating the gas stream to an elevated temperature and while directing the heated gas stream in the one direction for impingement against the moving and tensioned fabric at a location generally opposite the restraining contact therewith, and severing the fabric with the heated gas stream.  
  2. The combination, with a textile apparatus for handling textile fabric, of means for severing textile fabric and comprising means for moving the fabric along a predetermined path of travel, means for imposing on the fabric forces tensioning the fabric in the plane of the path, means contacting one face of the fabric for restraining the fabric against movement in one direction transversely away from the plane of the path, means for delivering a flowing stream of pressurized gas, and means for heating the gas stream to an elevated temperature and for directing the heated gas stream transversely of the plane of the path in the one direction and for impinging the heated gas stream against the other face of the fabric at a location generally opposite the location at which said restraining means contacts the one face of the fabric for severing the fabric at a location spaced inwardly from any side edge thereof.  
  3. In combination with a textile loom for manipulating textile yarns to form at a fabric forming location a woven textile fabric which includes at least some thermally degradable yarns, the fabric having at at least one edge successive separated weft yarn ends protruding therefrom and said loom having means for moving the fabric along a predetermined path of travel from the fabric forming location and means for imposing on the fabric forces tensioning the fabric in the plane of the path of travel; means for severing the fabric along a warpwise longitudinal line spaced inwardly of but adjacent to said one edge, said severing means comprising thermally insulating housing means mounted on said loom, means for supplying a flowing stream of noncombustible gas, means mounted within said housing means for receiving the gas stream and for heating the same to an elevated temperature of at least about 500F., and means for directing the heated gas stream transversely of said plane of the path and for impinging the heated gas stream against a face of the tensioned fabric at a velocity of at least about 6,000 feet per minute to sever the fabric while producing a smoothly cut edge.  
 4. The combination according to claim 3 wherein said stream supplying means supplies compressed air.