Abstract:
A method of producing a needled product of a selected material or materials of a desired thickness and size. A first carded batt of a selected material or materials is moved from a feed support into a needle loom between a vertically reciprocating needle bed and a support bed located beneath and in spaced relation to the needle bed. The needle bed and/or the support bed are vertically movable to vary the spacing therebetween. The upper surface of the first carded batt is penetrated by the needles in the needle loom so that the needles do not reach an upper surface of the support bed and are able to flex laterally. The needled first batt is then lifted and moved to the feed support or a feed support for another needle loom. Thereafter, a second batt is positioned over the first batt in overlapping relation, the needle bed or support bed is moved to increase the vertical spacing therebetween to accommodate the overlapped batts, and the batts are moved through the needle loom and connected. This method may be repeated to add additional overlapped batts to produce a layered product of any suitable thickness.

Description:
This application claims the priority of Provisional Patent Application No. 61/972,642 filed on Mar. 31, 2014. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to the manufacture of nonwoven materials and, more particularly, to a new and improved method and apparatus for producing nonwoven materials of any suitable thickness and/or composition. 
     Description of the Background Art 
     At the present time, substantially all needle looms for producing nonwoven materials such as felt have a maximum opening between the stripper plate for the needles and the upper surface of the supporting bed having holes for receiving the needles of about 3½ inches. Accordingly, the maximum thickness of needle felts produced by existing needle looms is about 1¾ inches and the maximum density is about 170 oz per square yard of product. This is because the number and pattern of needles is limited for the reason that the present needle looms are constructed so that the needles pass through the product to be needled and into aligned openings in the upper surface of the supporting bed. The number and pattern of needles, therefore, is limited by the pattern of openings in the supporting bed. 
     Current needle looms are constructed so that the vertical movement of the needle bed is limited to 1 9/16 inches to 3 inches. 
     Also, the speed of the material being advanced through the current needle looms is limited by the fact that the needles extend through the material into the openings in the supporting bed. Because the needles enter the openings in the supporting bed, they are subject to breakage if, for some reason, they are not properly aligned with the openings in the support bed. 
     As a result of the current needle loom constructions, the production of needle felts or nonwoven materials is limited to materials of small thickness, such as 1¾ inches maximum and this limitation limits the uses of such needle felts or nonwoven materials. 
     A need has risen, therefore, for a new and improved method and apparatus for producing needle felts and other nonwoven materials that can be used for any suitable or desired applications. The present invention meets this need and allows the creation of any density or oz per sq yd to any thickness requirement above the standard needling of 170 oz per sq. yard and 1¾″ thick. It also allows any desired or suitable synthetic fibers to be added to needle felts throughout the build, such as, e.g., ceramic fiber, high-purity alumina, zirconia, silica spun ceramic fibers or a base rayon viscose or cellulose base product prior to carbonization. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, a carded batt of any suitable material or combination of materials is advanced from a roll or in flat form on a feed apron into a needle loom that is constructed to vary the opening between the stripper plate or bed for the needles and the supporting bed for the batt to any suitable or desired size, e.g., a few inches to many feet as desired. As the batt is advanced through the needle loom, the needles in any suitable or desired pattern and density are reciprocated at any suitable or desired speed to penetrate the batt to tangle the fibers together and make the batt thinner, more compact and tighter as a result of the reciprocating movement of the needles generally in accordance with known technology. In the apparatus of the present invention, however, the needles do not extend completely through the batt into any holes in the supporting bed. Accordingly, the supporting bed may be of lighter construction, the needles may have limited lateral movement without worrying about breakage, and the reciprocating speed of the needles can be increased over the speed used in current needle looms. The needles may be of any suitable construction depending on the materials in the batt. 
     The distance between the stripper plate or needle bed and the support bed is adjusted to accommodate the thickness of the batt and the desired needle penetration thereof. The adjustment is accomplished by vertical movement of the support bed for the batt or vertical movement of the bed supporting the needles. 
     After the batt is needled and leaves the needle loom, it may be conveyed on a take up apron or the like to an apparatus for lifting the batt, turning it over to an inverted position and moving it again to the feed apron to be advanced into the same needle loom or another needle loom such that the batt is needled from the opposite side in both directions in a manner similar to that of the first needle penetration of the batt. 
     Thereafter, the double needled batt is removed from the needle loom by a suitable take up apron or the like and is moved to a position wherein it can be fed to the same or a different needle loom. Before advancing the double needled batt into the needle loom, another batt of any desired or suitable material is positioned on the double needled batt, the distance between the stripper plate or needle bed and the support bed of the needle loom is increased and the two batts in overlapped relation are advanced through the needle loom wherein the reciprocating needles extend through the upper batt into the lower batt short of the supporting bed to connect the two batts together. After the overlapped batts are removed from the needle loom by a take up apron or the like, the overlapped batts may then be lifted, inverted and transported to a feed apron or the like for movement into the same or a different needle loom wherein they can be needled from both directions in a manner as hereinbefore described. 
     Within the scope of the present invention, any suitable or desired number of batts of any suitable material, density or thickness may be added in overlapping relation to a needled batt as described herein without inverting the needled batt or the overlapped batts so that they are needled together from one direction only and not from both directions. The new and improved method and apparatus of the present invention, therefore, may be used to produce layered batts of any suitable thickness that are needled from one and/or two directions in any desired manner. 
     Thereafter, in accordance with the present invention, any suitable number of batts can be added to the needled batts, the opening between the stripper plate or needle bed and the support bed can be adjusted accordingly and the overlapped batts can be moved and needled in any desired manner to produce a multilayered batt of any suitable thickness limited only by the construction of the needle loom and the size of the opening between the stripper plate or needle bed and the support bed thereof. 
     In accordance with the method and apparatus of the present invention, the feed apron, needle loom and take up apron and devices are constructed and operate to insure for each cycle of operation that the needle beam movement and the movement of the batt or overlapped batts into, through and out of the needle loom is uniform and does not vary in speed. 
     With the improved method and apparatus of the present invention, layered and needled felts or nonwoven materials of any suitable or desired thickness can be constructed of any suitable material or materials and can be used for any desired application wherein lightweight strong materials are required such as in space or aircraft applications or any other desired applications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic side elevational view of an apparatus for conveying a carded batt of one or more materials through a needle loom; 
         FIG. 2 a    is an enlarged schematic side elevational view of a portion of an apparatus for conveying one or more layers or batts of a selected material or materials through a needle loom in accordance with the present invention, showing the needle bed at the upper end of its reciprocating movement; 
         FIG. 2 b    is a side elevational view similar to  FIG. 2 a    showing the needle bed at the lower end of its reciprocating movement; 
         FIG. 3  is a side elevational view of one embodiment of a movable support bed for the apparatus shown in  FIGS. 2 a    and  2   b;    
         FIG. 4  is a side elevational view of a portion of a needling apparatus showing another embodiment of a movable support bed; 
         FIG. 5 a    is a perspective view of one embodiment of a needle loom with a movable support bed like the one shown in  FIG. 4 ; 
         FIG. 5 b    is an enlarged perspective view of a portion of the needle loom shown in  FIG. 5   a;    
         FIG. 6  is a side elevational view of a portion of a needling apparatus showing a further embodiment wherein the support bed is fixed and the needle bed and associated portions of the apparatus are movable; 
         FIG. 7  is a perspective view of a further embodiment of a needle loom having a movable needle bed like that shown in  FIG. 6 ; 
         FIG. 8  is a schematic view of a needle from a needle loom extending through a stripper plate on its down stroke into the fiber of one or more batts in a needle loom of the present invention; 
         FIG. 9  is a view similar to  FIG. 8  showing the needle at the bottom of its stroke through the batt; 
         FIG. 10  is a view similar to  FIGS. 8 and 9  showing the needle on its upstroke through the fiber of the batt; 
         FIG. 11 a    is a side elevational view of one embodiment of a needle for use in the needle loom of the present invention; 
         FIG. 11 b    is an enlarged side elevational view in section of a portion of the needle shown in  FIG. 11   a;    
         FIG. 12  is a perspective view of an apparatus for conveying a batt or layers of batts through a needle loom with a movable needle bed and for lifting a needled batt or layers of batts exiting the needle loom and conveying them to a feed apron in an inverted or another position so that they can be again conveyed through the needle loom; 
         FIG. 13  is a side elevational view of a portion of the apparatus shown in  FIG. 12 ; 
         FIG. 14  is a perspective view similar to  FIG. 12  of an apparatus for conveying a batt or batts through a needle loom having a movable support bed; 
         FIG. 15  is a perspective view of a crane for moving and/or inverting or turning over a needled batt or batts showing a track system for moving the crane; 
         FIG. 16  is a perspective view of a portion of the apparatus shown in  FIG. 14  wherein the crane is positioned to pick up a needled batt or batts from the take up apron; 
         FIG. 17  is a perspective view similar to  FIG. 16  wherein the crane has lifted the needled batt or batts from the take up apron; 
         FIG. 18  is a perspective view of a portion of the apparatus shown in  FIG. 14  showing the crane at the beginning of the feed apron with the needled batt or batts supported on the crane being rotated to be inverted; 
         FIG. 19  is a perspective view similar to  FIG. 18  showing the needled batt or batts supported by the crane being turned over completely; 
         FIG. 20  is a perspective view similar to  FIGS. 18 and 19  wherein the turned over or flipped needled batt or batts are again positioned on the feed apron for movement into the needle loom for additional needling in the opposite direction and on the opposite side thereof; 
         FIG. 21  is a perspective view of a portion of a feed apron or conveyer for a needle loom in accordance with the present invention; 
         FIG. 22  is a perspective view of a portion of the feed apron shown in  FIG. 21  showing a holding or pushing rail and associated operational devices; 
         FIG. 23  is an exploded perspective view of the feed apron components shown in  FIG. 22 ; 
         FIGS. 24 a , 24 b  and 24 c    show various views of the slats of the feed apron shown in  FIG. 21 ; and 
         FIG. 25  shows enlarged perspective views of portions of the take up apron and associated apparatus shown in  FIGS. 12 and 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1 , a batt B is fed by a feed apron  10  into a needle loom  12  of any suitable construction wherein the batt is engaged by a predetermined number and pattern of reciprocating needles (not shown) for the purpose of compacting and tightening the fibers of the batt. The batt B is then removed from the needle loom  12  by a take up apron  14  and associated apparatus of any suitable construction for storage, shipping or further processing. In accordance with the present invention, the batt B may be positioned on a needled batt or overlapped batt layers B 1  that are positioned on the feed apron  10  for passage through the needle loom  12  in overlapped relation, as will be further explained in more detail hereinafter. 
     As shown schematically in  FIGS. 2 a  and 2 b   , the new batt B and/or the underlying needled batts B 1  can be conveyed through the needle loom  12  wherein they are engaged by needles  13  on a vertically reciprocating needle bed  16  and are supported by a bed  18  that is vertically movable by a hydraulic device or any other suitable device to vary the spacing between the support bed  18  and the stripper plate  19  to accommodate one or more layers of batts to be needled of different thicknesses. In accordance with one embodiment of the invention, a hydraulic cylinder  20  may be located in a pit  22  of any suitable size or depth that is positioned beneath the needle loom  12  and operates to move the support bed  18  vertically, as shown in  FIG. 3 . 
     Referring to  FIG. 2 b   , on the down stroke of the needle bed  16 , the needles  13  pass through the stripper plate  19  and penetrate the batt B or batts B 1 . As will be explained hereinafter, in accordance with the present invention, the needles  13  do not enter the support bed  18 . 
     In accordance with another embodiment of the invention shown in  FIGS. 4, 5   a  and  5   b , the support bed  18  is slidably mounted on the frame  21  of the needle loom  12  for vertical movement in relation to the needle bed  16  and stripper plate  19 . The needle bed  16  is mounted on the frame  21  for limited vertical reciprocating movement thereon. The frame  21  is fixed in position on the floor and thus is not movable to vary the spacing between the needle bed  16  or stripper plate  19  and the support bed  18 . A jack support system  23  of any suitable construction mounted on the frame  21  is connected to the support bed  18  and is operable mechanically or hydraulically to vary the spacing between the support bed  18  and the stripper plate  19  up to about two feet. 
       FIGS. 6 and 7  illustrate a further embodiment of the present invention wherein a new and improved needle loom  100  comprises a needle bed  102  that is mounted for reciprocal movement on the frame  104  secured to a plurality of vertically extending legs  106  that are telescopically mounted on vertically extending supports  108  secured to base pads  110  that include any suitable type of shock absorbing devices. The legs  106  are vertically movable on the supports  108  by any suitable type of hydraulic or mechanical drive means (not shown). 
     The upper portion of the needle bed  102  comprises a suitable type of drive apparatus  112  for the vertical reciprocal movement of the needle bed  102  and needles  103  connected thereto. 
     A support bed  114  is positioned under the needle bed  102  and is fixedly mounted on base girders  116  of any suitable type. 
     The sturdy construction of the needle loom  100  enables the vertical spacing between the support bed  114  and the stripper plate  119  to be varied a significant amount, e.g., up to ten feet or more, by vertical movement of the frame  104  secured to the support legs  106  that are vertically movable on the supports  108 . This construction also minimizes any vibration that may occur from reciprocating movement of the needle bed  102 . In cases where the needle loom  100  is constructed for significant vertical spacing between the support bed  114  and the needle bed  102 , additional support legs  106  and supports  108  may be provided on the needle loom  100 . 
       FIGS. 8-10  illustrate schematically the reciprocating movement of a needle in accordance with the principles of the present invention. As shown in  FIG. 8 , on the down stroke of a needle N of any suitable or desired construction, the needle extends through an aligned aperture in a stripper plate  200  of a needle loom (not shown) and engages the fibers of a batt  202  formed of one or more layers being advanced between the stripper plate  200  and the support bed or plate  204  of any suitable construction. During the downstroke of the needle N, fiber gathers inside of barbs on the needle that continue to grab strands of fiber and draw them down towards the support bed  204 . At the bottom of the stroke of the needle N, as shown in  FIG. 9 , the needle stops short of the support bed  204  and therefore does not enter into the plane of the support bed  204  in accordance with the present invention. In this manner, the support bed  204  may be of simple lightweight construction without any apertures therethrough and the needle N may be free to move laterally to a limited extent in any direction without any danger of breakage by not being aligned with apertures in the support bed  204 . Depending on the type of needle N used in the needle loom and the type of fibers in the batt  202 , the use of a stripper plate  200  on the needle loom (not shown) may not always be necessary. 
     On the upstroke of the needle N as shown in  FIG. 10 , the fibers of the batt  202  begin to tangle together, the thickness of the batt  202  is reduced and the batt becomes more compact and tighter. As more needle penetrations occur, the tightness of the batt will increase and its thickness will decrease up to a certain point which is controlled by the penetration depth of the needle, the number of barbs on the needle, and the number of penetrations of the needle. 
       FIGS. 11 a  and 11 b    illustrate one example of a needle N that may be used in a needle loom constructed in accordance with the present invention. The needle N comprises a plurality of barbs  206  in its lower portion that grab strands of fibers  208  and push them downwardly on the downstroke of the needle N through a batt being advanced between a stripper plate and a support bed of a needle loom. 
     In accordance with the present invention, any suitable needle construction may be used in a needle loom depending on many factors such as the composition and thickness of the batt or layers of batts being advanced through the needle loom and the depth and reciprocating speed of penetration of the needles into the moving batt. 
       FIGS. 12-20  illustrate different embodiments of an apparatus  300  for performing the new and improved method of the present invention comprising the following basic steps:
         1. Advancing a carded batt of a selected material or materials through a needle loom between the stripper plate and support bed of a needle loom which is constructed in accordance with the present invention to vary the vertical spacing between the stripper plate and support bed a significant amount to accommodate a batt or layers of batts of significant thickness, e.g., up to ten feet or more;   2. Adjusting the vertical spacing between the stripper plate and the support bed for a predetermined penetration of the batt or layers of batts by the needles on the needle bed;   3. Limiting the downward movement of the needles on the needle bed through the advancing batt such that the needles do not penetrate or contact the support bed which allows the needles to be mounted for limited lateral movement in any direction to reduce needle breakage;   4. Removing the needled batt from the needle loom onto a take up apron of any suitable construction;   5. Lifting the needled batt from the take up apron, and moving it in the same or an inverted position to a feed apron for the needle loom or another needle loom;   6. Advancing an inverted needled batt through the needle loom so that it is needled in the opposite direction and on the opposite side thereof;   7. Removing a double needled batt from the needle loom onto a take up apron and moving it again to a feed apron;   8. Positioning a second carded batt over a single or double needled batt on the feed apron and advancing and connecting the batts in overlapped relation through a needle loom which has been adjusted to increase the spacing between the stripper plate and the support bed to accommodate the increased thickness of the overlapped batts;   9. Moving the layered, needled and secured batts to the take up apron for the needle loom and lifting and moving them in the same or an inverted position to a feed apron for the same or another needle loom for a repeat of the same cycles as hereinbefore described which can be repeated a desired or selected number of times to produce a layered batt of any suitable thickness.       

     Referring to  FIGS. 12-20 , the apparatus  300  generally comprises a feed apron  302 , a needle loom  304  or  304   a , pinch rolls  306 , a take up apron  308  and an overhead crane  310  that is movable longitudinally over the feed apron, needle loom and take up apron. 
     The feed apron  302  may be of any suitable construction and, in one embodiment of the present invention, comprises upstanding bars  312  for engaging the rear portion of a batt and overlying clamp arms  314  or the like for holding the batt on the feed apron  302  as will be more fully disclosed hereinafter. 
     The needle loom  304  may be of any suitable construction in accordance with the present invention, such as the construction shown in  FIG. 5 a    or  7  wherein the vertical distance between the stripper plate and the support bed can be varied to a significant extent as hereinbefore explained. 
     The pinch rolls  306  may be of any suitable construction for advancing the needled batt or batts in a uniform manner onto the take up apron  308  which also may be of any suitable construction and may comprise movable clamp arms  316  for holding the batt B on the take up apron. To insure that a needled batt or batts of certain materials, such as viscose or cellulose fibers used in a carbon/carbonization process, are metal free, the apparatus  300  also comprises a magnet  307  and metal detector  309  positioned between the needle loom  304  and the take up apron  308 . 
     As shown in  FIG. 15 , a crane  310  is longitudinally movable over the feed apron  302 , the needle loom  304  and the take up apron  308  in any suitable manner, such as by mounting it for movement on a track  318  or the like. The crane  310  comprises a frame  320  having support arms  322  slidably mounted on the upper portion thereof for lateral movement. Each arm  322  comprises vertically moveable legs  324  having a clamp mechanism  326  rotatably mounted on the bottom portion thereof. The vertically movable legs  324  may be of any suitable construction, such as a telescoping construction, and may be movable by any suitable hydraulic or mechanical means (not shown). 
     Each clamping device  326  may be of any suitable construction to enable it to engage and pick up a batt or layered batts on the take up apron  308  when the crane  310  is positioned over the take up apron and to deposit them on the feed apron in the same or an inverted position when the crane is moved to a position over the feed apron. 
     In an illustrative embodiment, each clamp mechanism  326  comprises an inwardly extending fixed bottom plate  328  and an inwardly extending top plate  330  that is vertically movable with respect to the bottom plate  328 . 
     In the operation of the apparatus  300  in accordance with the method of the present invention, the crane  310  is movable over the take up apron  308  to engage and pick up a needled batt or layers of batts B that have been moved onto the take up apron  316  from the needle loom  304 , as shown in  FIG. 12 . This is accomplished by moving the support arms  322  outwardly, moving the support legs  324  downwardly so that the fixed bottom plate  328  of each clamp device  326  can be inserted under the adjacent batt or layers of batts on the take up apron  308 , moving the support arms  322  inwardly to insert the fixed bottom plates  328  under the batt or layers of batts B, moving the top plates  330  downwardly into engagement with the top of the batt B and moving the support arms  324  upwardly to lift the batt B upwardly from the take up apron  308 , as shown in  FIGS. 16 and 17 . 
     The crane  310  is then moved to a suitable position wherein the clamp devices  326  may be rotated approximately 180° on the support legs  324  when it is desired to invert or turn the supported batt B over on its opposite side as shown in  FIGS. 18 and 19 . 
     Thereafter, as shown in  FIG. 20 , the crane  310  is moved to a position over the feed apron  302 , the support arms  324  are moved downwardly to position the movable plates  330  on the clamp devices  326  on the feed apron  302 , the movable plates  330  are moved away from the fixed plates  328  of the clamp devices  326 , the support arms  322  are moved laterally outwardly to remove the movable plates  330  from the supported batt B so that the batt B rests on the feed apron  302  in the same or an inverted position. An inverted batt B can then be advanced into the needle loom  304  so that it is needled in the opposite direction and also on the opposite side. 
     The described operation of the apparatus  300  can then be repeated in the manner shown in  FIGS. 12-20  to pick up batts or layers of batts from the take up apron  308  and deposit them in the same or an inverted position on the feed apron  302 . In this manner, layers of batts B can be needled together in the same or different directions and on different sides, if desired, to produce a layered batt of any desired thickness and composition, and the spacing between the stripper plate and the support bed of the needle loom  304  can be increased to accommodate the increases in thickness of the layered batts, as hereinbefore described. 
     For the operation of the method and apparatus of the present invention, it is essential that a batt or layered batts be moved into, through and out of the needle loom at a constant speed. To accomplish this, the apparatus of the present invention comprises a new and improved feed apron, take up apron and associated devices. 
     Referring to  FIGS. 12 and 21-24   c , the feed apron  302  is formed of slats  303  that are connected by hinges  305  and have longitudinal grooves  311  on the inner surfaces thereof that are engaged by teeth  313  on supporting end rollers  315  for moving the feed apron  302  between and over the end rollers  315 . The feed apron  302  is supported at its upper portion by a plurality of support rollers  317 . 
     A plurality of holding or pushing rails  319  are movably mounted on the slats  303  for engaging a batt or overlapped batts on the feed apron  302  to advance the batt or batts on the feed apron  302  at a constant speed into a needle loom  304  and  304   a . The apparatus for moving the rails  319  is illustrated in  FIGS. 22 and 23  and generally comprises an air cylinder  321  or the like, guide devices  323 ,  325  and gearing  327 . 
     As an alternative, the fed apron may comprise upstanding bars  312  and overlying clamp arms  314  as shown in  FIG. 12  that are operated in any suitable manner. 
     The take up apron  308  shown in  FIGS. 12 and 25  generally comprises a movable conveyor belt  329  and movable clamp arms or pinch rollers  316  for holding a batt or overlapped batts and moving them at a constant speed out of the needle loom  304 ,  304   a.    
     Drive rollers  331  are positioned at the exit end of the needle loom  304 ,  304   a  and pinch rollers  306  are positioned above them to hold a batt or batts down on the drive rollers  331  and move them at a constant speed out of the needle loom  304 ,  304   a  and onto the take up apron  308 . 
     A removable table  333  may be positioned between the drive rollers and the take up apron  308  when the batt or batts cannot be rolled. 
     From the foregoing description, it will be readily seen that the new and improved method and apparatus of the present invention can be used to produce a needled batt of any suitable material or materials and of any desired thickness and size for use in any desired field of use. Because layered needled batts of lightweight, strong and heat resistant materials of any suitable thickness can be effectively produced by the method and apparatus of the present invention, such layered batts are especially useful in aerospace and space applications, high temperature environments, marine applications or any other desired fields. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.