Abstract:
A chopper for chopping continuous items like fiber, fiber strand, yarn, string, wire, tape or ribbon, etc. which enters the chopper in unwound form at a high linear speed is disclosed having improvements that permit the chopper to tilt to change the angle of discharge of the chopped item(s). Also disclosed is a fast acting roll retainer and a chopper having the fast acting roll retainer that permits a backup roll and a blade roll to be removed and replaced in a faster and less damaging manner. Methods of chopping and changing rolls on an apparatus using the disclosed apparatus are also disclosed.

Description:
BACKGROUND 
     The present invention involves an improved chopper for chopping continuous or very long fiber, fiber strands, yarn, string, wire, ribbon, tape and the like comprising a backup roll and a blade roll. More specifically, the present invention involves a chopper having a novel quick release knock off-knock on roll retainer for the rolls that must be frequently changed, and means for tilting the chopper to change the angle of discharge of the chopped strand, etc. 
     It has long been known how to chop continuous fibers or fiber strands into short lengths of about 3 inches or shorter. More than a billion pounds of such products including chopped glass fibers and fiber strands are produced each year in processes and chopping apparatus like those disclosed in U.S. Pat. Nos. 5,970,837; 4,398,934; 3,508,461; and 3,869,268. The choppers disclosed in these patents comprise a blade roll containing a plurality of spaced-apart blades for separating the fibers into short lengths, a backup roll, frequently driven, which the blades work against to effect the separation and which pulls the fibers or fiber strands, often using an idler roll to hold the fibers or fiber strands down onto the surface of the backup roll. In the chopped fiber processes disclosed in these patents, the chopper is usually the most productivity limiting equipment in the processes that typically operate continuously every day of the year, 24 hours each day. Therefore, improvements in the chopper that allow the chopper to pull and chop faster, allow longer times between maintenance shutdowns, and/or to pull and chop more fibers or fiber strands at a time have an extremely positive impact on productivity and production costs. 
     Due to wear, the blade roll and backup roll on each chopper must be changed frequently with the actual life between changes depending upon the type of item being chopped. The life typically ranges between 4 and 24 hours or more, but a defect in a blade or the elastomer layer on the backup roll can cause even shorter life. Due to their tightness on their spindles and the tacky chemical sizing from the fiber that gets on all exposed parts, it has been necessary to strike the old blade rolls and old backup rolls with a hammer or a heavy bar to loosen them from their spindles before they could be removed for replacement with new rolls. This hammering damages the rolls and in time knocks them out of alignment causing vibration and premature replacement. These are expensive problems for the industry considering that there are hundreds of fiber choppers in operation. 
     Another problem with fiber choppers when chopping wet fiber having a tacky chemical sizing on the surface of the fibers is that the stream of fibers will, depending on factors such as moisture content and the degree of tackiness of the sizing, leave the chopper at different angles. This presents a problem in catching the fiber with a conveyor belt due to the limited space in the fiber forming rooms where the fiber is formed and chopped and results in some fiber being thrown off the conveyor and onto the floor causing scrap and a housekeeping problem. This problem is discussed in U.S. Pat. No. 4,161,897 and the problem is addressed in that patent by designing the chopper such that the position of the blade roll can be changed to contact the backup roll in different locations. While this may change the angle of discharge of the chopped fiber, it greatly complicates the design and is a costly solution. A simpler, less costly solution has been needed. 
     SUMMARY OF THE INVENTION 
     The present invention includes an improved chopper that comprises a backup roll and a blade roll, each roll being mounted on a spindle with a novel fast acting knock off/knock on roll retainer for holding the blade roll and/or the backup roll in place and for pulling the roll(s) loose from its spindle. This roll retainer assembly comprises a spinner attached to a stub shaft at or near one end, the stub shaft having engaging means that will engage with the spindle for the roll, a locking cup surrounding the stub shaft and free to rotate around the stub shaft, the locking cup having a depression therein with an opening facing away from the spinner, a lock-ring or collar surrounding the stub shaft and residing in the depression in the locking cup, the lock-ring being fixed to the stub shaft. The roll retainer also comprises a locking plate attached to the open end of the lock cup, the locking plate having two or more slots therein for allowing heads of shoulder bolts that are fastened to the blade roll and/or backup roll at locations spaced from the axis of the roll to pass into or through the slots in a wide portion of the slots. At least one end portion of each slot is narrower than the heads are wide such that the heads cannot pass through the narrower end portion(s) of the slots. 
     Preferably the assembly also includes a thrust washer or a lubricated washer around the stub shaft and between the spinner and the lock cup to enhance the tightening and loosening of the spinner. Preferably the roll retainer also comprises a lubricated thrust washer in the bottom of the depression in the lock cup to enhance relative movement under stress between the locking ring and the lock cup. Also, preferably the roll has two or more shoulder bolts circumferentially spaced around the opening, most preferably equidistant from each other and from the axis of the roll. This chopper can also comprise means on or attached to the chopper for lifting one side of the chopper to tilt the chopper to change an angle of discharge of an array of chopped product discharging from the chopper. 
     The present invention also includes a fast acting roll or wheel retainer comprising: 
     a) a cylindrical stub shaft having one end portion threaded, 
     b) a locking ring having a spaced apart parallel surface perpendicular to and surrounding the stub shaft and being either integral with the stub shaft or being rigidly attached to the stub shaft, 
     c) a spinner having one or more handles, the spinner being located at or near an end of the stub shaft opposite the end that is threaded, the spinner being either integral with the stub shaft or rigidly attached to the stub shaft, 
     d) a lock cup having a bottom and an open top, the bottom of the locking cup having a hole therein and surrounding the stub shaft in a ratable manner at a location between the two ends of the stub shaft, the open top of the locking cup being closest to the threaded end of the stub shaft, and 
     e) a locking plate attached to the open end of the lock cup, the locking plate having a hole therethrough for the stub shaft to reside in a rotatable manner, the locking plate having one or more slot openings at least partially therethrough and spaced from the hole for the stub shaft, each slot opening having a wide portion and a narrower portion, one face of the locking plate being compatible with an engaging face on the roll or wheel and the area on an opposite face around the narrower portion of each slot being compatible to engage a bottom surface of an enlarged head of one or more projections extending from an outboard surface of said roll. 
     The present invention also includes a method of removing a used roll and replacing it with a new or repaired roll, each roll having an opening around its axis and at least two shoulder bolts with enlarged heads spaced from its axis and protruding from a face of the roll, on a chopper, or other apparatus, having a spindle with threads on a working end using a novel knock on/knock off roll retainer assembly that comprises a spinner attached to a stub shaft at or near one end, the stub shaft having engaging means that will engage with the spindle, a lock cup surrounding the stub shaft and free to rotate around the stub shaft, the lock cup having a depression therein with an opening facing away from the spinner, a lock ring or collar surrounding the stub shaft and residing in the depression in the lock cup, the lock ring being fixed to the stub shaft and a locking plate attached to the open end of the lock cup, the locking plate having one or more slots therein for allowing heads of projections fastened to the blade roll and/or backup roll at locations spaced from the axis of the roll to pass through a wide, central portion of each slot, at least one end portion of each slot being narrower than the heads are wide such that the heads cannot pass into or through the narrower end portion(s) of the slots, comprising the steps of: 
     a) rotating the spinner in a direction to back the stub shaft off a spindle having a threaded portion such that an outer face of the locking plate which is in contact with the enlarged heads of the shoulder bolts will pull the used roll loose from the spindle without damaging the roll, 
     b) rotating the locking plate such that the wide portion of the slots align with the enlarged heads of the shoulder bolts, 
     c) rotating the spinner to back the stub shaft off of the spindle while preventing the locking plate from rotating and removing the roll, 
     d) placing a new or repaired roll onto the spindle such that a portion of the spindle is in the opening of the roll and such that the two or more projections are facing away from the chopper or other apparatus, 
     e) threading the threaded stub shaft of the roll retainer assembly onto the spindle, 
     f) aligning the slots in the locking plate so that the wide portion of the slots align with the enlarged heads of the shoulder bolts on the roll, 
     g) rotating the spinner to move the stub shaft further onto the spindle while maintaining the alignment of the slots as described in (f) above until the lock plate is against a hub of the roll and the roll is snugly in place on the spindle, and then backing off the stub shaft by rotating the spinner in the opposite direction about 5 to about 180 degrees, 
     h) rotating the locking plate until the end of the slots at the narrower end portion engage the shoulder bolts, and 
     i) rotating the spinner to move the stub shaft onto the spindle the amount backed off in step (g) and then knocking the spinner or a projection on the spinner to tighten the roll on the spindle. 
     The present invention also includes a chopper for separating long fiber, fiber strands, string, wire, tape or ribbon into short pieces and discharging the short pieces in a direction away from the chopper, the chopper comprising a blade roll, a backup roll and a frame, the improvement comprising means for varying the elevation of one end of the frame of the chopper for the purpose of changing the angle of discharge of the short pieces from the chopper or for maintaining the angle of discharge the same when a different item is fed into the chopper, i.e. an item which has a different tendency to adhere to the elastomer layer on the backup roll. The means for varying the elevation is preferably a jack screw, but can be any known compact means of lifting including a gas cushion lifting device, a fluid cylinder lifting device, a mechanical lever type lifting device similar to a bumper jack with lock, a chain hoist or winch mounted above the chopper frame, and other equivalent lifting devices or shimming means. 
     Preferably, the lower side of the chopper opposite the lifting means is pivotly mounted to a foot or feet that is/are bolted to the floor or otherwise equipped so that the feet won&#39;t slide along the floor when the opposite end is raised by the lifting means. The chopper can be any chopper having a backup roll and a blade roll including the improved chopper using the novel roll retainer described above. 
     The present invention also includes a chopper for chopping items selected from the group consisting of fibers, fiber strand, yarn, string, wire, and ribbon, tape that enter the chopper in an unwound form at a high linear speed into an array of short lengths, the chopper having an upstream side and a downstream side and a blade roll and a backup roll, the improvement comprising: a second framework or an inner frame or member on which the chopper is mounted, the second framework or inner frame or member being pivotly supported near one side of the chopper by a first framework or an outer frame surrounding at least a part of the second framework or inner frame or member, and lifting means attached to an opposite side of the chopper, said opposite side of the chopper being opposite the side that is near where said inner frame is pivotly supported. 
     The present invention also includes a method of separating long lengths of items such as fiber, fiber strands, string, wire, tape or ribbon into short pieces by passing the items continuously into a nip between a rotating blade roll and a rotating backup roll of a chopper whereby the item is separated into short pieces which are discharged from the chopper in an array having a direction, the improvement comprising changing the elevation of one end of the chopper with respect to an opposite end of the chopper to change the direction of the array of short pieces. 
     When the word “about” is used herein, it is meant that the amount or condition it modifies can vary some beyond that so long as the advantages of the invention are realized. Practically, there is rarely the time or resources available to very precisely determine the limits of all the parameters of one&#39;s invention because to do so would require an effort far greater than can be justified at the time the invention is being developed to a commercial reality. The skilled artisan understands this and expects that the disclosed results of the invention might extend, at least somewhat, beyond one or more of the limits disclosed. Later, having the benefit of the inventor&#39;s disclosure and understanding the inventive concept and embodiments disclosed, including the best mode known to the inventor, the inventor and others can, without inventive effort, explore beyond the limits disclosed to determine if the invention is realized beyond those limits and, when embodiments are found to be without unexpected characteristics, those embodiments are within the meaning of the term “about” as used herein. It is not difficult for the skilled artisan or others to determine whether such an embodiment is either as might be expected or, because of either a break in the continuity of results or one or more features that are significantly better than reported by the inventor, is surprising and thus an unobvious teaching leading to a further advance in the art. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of a typical prior art chopper. 
     FIG. 2 is a front view of a chopper according to the present invention and also shows in phantom the chopper in a tilted position according to the present invention. 
     FIG. 2A is a plan view of the chopper shown in FIG.  2 . 
     FIG. 3 is a partial expanded front view of a backup roll having a knock on/knock off roll retainer shown in FIG.  2 . 
     FIG. 4 is a partial expanded side view of a backup roll, spindle, and the knock on/knock off retainer shown in FIGS. 2 and 3. 
     FIG. 5 is a partial front view of another embodiment of the invention related for tilting the chopper. 
     FIG. 6 is a partial front view of still another embodiment of the invention for tilting the chopper. 
     FIG. 7 is a perspective view of a preferred chopper base for tilting the chopper showing in phantom a portion of the chopper mounted on the base. 
     FIG. 8 is a front view of the preferred base shown in FIG. 7 which also shows part of the chopper mounted thereon. 
     FIG. 9 is a perspective view of a still further embodiment which is a modification of the embodiment shown in FIG.  7 . 
     FIG. 10 is a perspective view of a still further embodiment which is another modification of the embodiment shown in FIG.  7 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a typical prior art chopper  2  comprising a front plate  4  attached to a structural frame (not shown) with a foot  5  at each corner, a blade roll  6  having spaced blades  7  protruding from its periphery. A backup roll  8  comprised of a hub  9 , preferably with cutouts and spokes, a rim  10  and an elastomer layer  11  on the rim  10  for the blades  7  to work against. The hub  9  can be continuous or solid with no cutouts or open spaces since the cutouts or open spaces are for the purpose of reducing the weight of either roll. 
     The continuous or long item(s)  12 , for example fiber strands, to be chopped or separated are held against the elastomer layer  11  of the backup roll  8  with an idler roll  13  which permits the rotating backup roll  8  to pull the item(s)  12  into the chopper  2  and on into the nip  14  between the blade roll  6  and the elastomer layer  11 , usually at high linear speeds, 1000 or more feet per minute off-line and 2000 or more ft./min. on-line, which chops or separates the item(s)  12  into short lengths  15 , such as chopped fiber strands. When the chopper  2  is working on loose items  12  like fibers, fiber strands, yarn, string or wire, the individual strands, etc. are typically separated from each other and guided onto the elastomer layer  11  with a separator or guide roll  16 . The blade roll  6  and the backup roll  8  are mounted on spindles  17 ,  18  respectively and are held tight onto these spindles with large nuts  19 ,  20  respectively. Choppers of this type are well known and are more fully described in U.S. Pat. Nos. 5,970,837; 4,398,934; 3,508,461; and 3,869,268, the disclosures of which are incorporated herein by reference. 
     FIG. 2 shows chopper  2  modified according to the present invention having a novel, fast acting knock on/knock off roll retainer assembly A holding the blade roll  6  and the backup roll  8  onto their respective spindles  17  and  18 , and preferably also comprising a chopper tilting assembly B. The roll retention assembly A can be used on either one of the blade roll  6  or the backup roll  8 , and preferably is used on both. Preferably one lower end of the chopper opposite the tilting assembly B is mounted in a pivoting manner on one or preferably two legs  21  on a floor mount or plate  64 , preferably with brackets  22  attached to a bottom side of the chopper and connected to the legs  21  with pins  23  to allow the chopper  2  to be tilted by the tilting assembly B which will be described in detail later. Preferably, the floor mount  64  has four feet  39  to allow prongs of a conventional walking lift truck to move under the floor mount  64  to lift and move the chopper  2 . 
     The roll retainer assembly A is shown in detail in FIGS. 3 and 4 and is comprised of a spinner  24 , preferably having at least one handle  25  and most preferably two or three handles  25 . The spinner  24  is integral with or rigidly attached at or near one end of a stub shaft  26  which is threaded on an end portion  27 , preferably on the outside of the end portion  27  of the stub shaft  26 , however in an alternative embodiment the stub shaft  26  could be a pipe and could be threaded on the inside of the pipe. In the latter embodiment, the stub shaft  26  would fit over a threaded end of a spindle. 
     The roll retainer A also comprises a locking plate  28  having at least one, and preferably three, slots  29  therein that extend at least partially and preferably completely through the thickness of the locking plate  28  and also having a circular hole  30  of a diameter sufficient to slip around the stub shaft  26  and preferably also an end  32  of the spindle  34  for either the backup roll  8  or the blade roll  6 . Since the roll retainer A is usable on both the blade roll  6  and the blade roll  8 , the term roll or roll  6 , 8  will be used hereafter to mean either roll. 
     A centerline of each slot  29  is preferably an arc, being a radius of the axis of the stub shaft  26 . Each slot  29  is also spaced from an outer periphery of the hole  30  and has a wide portion  35  and at least one narrower end portion  36 . Preferably, each slot  29  has a narrower end portion  36  on each end of the wide portion  35 , as shown in FIG.  3 . 
     Preferably the locking plate  28  is circular with the spinner  24  rigidly attached to and centered on the stub shaft  26 , the latter protruding through the hole  30  in the locking plate  28  such that the spinner  24  is spaced from an outboard face  37  of the locking plate  28  and the end portion  27  of the stub shaft  26  being spaced from an inboard face  38  of the locking plate  28 . The outboard face  37  of the locking plate  28  should be parallel to the inboard face  38  of the locking plate  28 , at least in an area adjacent to the narrow end portion(s)  36  of the slots  29 . 
     The locking plate  28  is bolted to a locking cup  40  that surrounds the stub shaft  26  between the spinner  24  and the locking plate  28 , preferably with a plurality of socket head cap screws  42 , the heads of which are recessed in the inboard face  38  of the locking plate  28 . The locking cup  40  has a circular hole  44  having a diameter slightly larger than the diameter of the stub shaft  26  and completely through its bottom surface  41  so that the locking cup  40  can rotate around the stub shaft  26 . The locking cup  40  is oriented on the stub shaft  26  such that its bottom  41  is close to the spinner  24  and its top surface butts against the outboard face  37  of the locking plate  28 . 
     Optionally, but preferably, a thrust washer or pre-lubricated washer  46  surrounds the stub shaft  26  in a loose and rotatable manner between the spinner  24  and an exterior bottom surface  43  of the locking cup  40  to allow the spinner  24  and the stub shaft  26  to more easily rotate, while under stress and while the exterior bottom of the cup  40  remains stationary. A suitable washer for this purpose is an oil impregnated bronze thrust type washer. Other thrust washers can be used so long as they don&#39;t deform excessively under the load to cause binding to the bottom exterior surface  41  of the locking cup  40 . Any type of thrust washer can be used. Lubrication of the washer  46  helps to prevent fiber sizing from drying and sticking to the washer surfaces. 
     A lock ring (collar)  48  surrounds the stub shaft  26  and is rigidly attached such as by being welded to the stub shaft  26  as with welds  49 . The lock ring  48  can be rigidly attached to the stub shaft  26  in any suitable manner, such as welding, or could even be an integral part of the stub shaft  26 , but this case the spinner  24  is not integral with the stub shaft  26 . The lock ring  48  is attached to the stub shaft  26  such that it is contained in and surrounded on its periphery by the locking cup  40  with a face of the lock ring  48  closest to, but spaced from, an interior bottom surface  45  of the locking cup  40  and an opposite face closest to the locking plate  28 . Optionally, but preferably, a lubricated thrust washer  50  surrounds the stub shaft  26  and resides in the space between the interior bottom surface  45  of the lock cup  40  and the face of the lock ring  48  closest to the interior bottom surface  45  of the locking cup  40 . The thrust washer  50  is preferably the same type washer as the thrust washer  46 . The purpose of the thrust washers  46  and  50  will be described later in the description of the knock on/knock off roll retainer A. 
     The roll spokes and hub  9  for use with the preferred roll retainer A illustrated here has a hole  51  centered around its axis and oversized for the spindle so that the hole  51  can receive an insert  52 . The insert  52  is securely attached, preferably by a pressed fit or strong adhesive, to the hub  9  of the roll  8 . It is further held in place with recessed bolts  54 , or an equivalent, passing through a flange  56  adjacent the insert  52  and into the hub  9 . The outer diameter of the flange  56  is larger than that of the insert  52  whose outer diameter is preferably just slightly greater than the diameter of the hole  51  in the hub  9 . The insert  52  and flange  56  could be an integral part of the hub  9 . 
     The insert  52 , including the flange  56 , has a hole through it centered around its axis. The diameter of the hole is preferably smallest, as installed on the chopper  2  and spindle  34 , on an outboard side and tapers to a larger diameter on the inboard side to fit a preferred reverse taper on an outboard end of the spindle  34 . This taper insures a tight fit of the insert  52  onto the spindle  34 , but also is what has made it necessary to strike the backside of the roll or pry the backup and blade rolls off their spindles. This is not necessary with the knock on/knock off roll retainer of the present invention. 
     The spindle  34  need not be tapered on the portion that engages the hub  9  of the rolls  6 , 8  or the insert  52 , but can be of uniform diameter and can also have ridges or grooves to engage grooves or ridges in the insert  52  to insure against slippage. In any case, rolls  6 , 8  have been difficult to get loose from the spindle when it is desired to remove the rolls  6 , 8  after they have been in operation chopping for at least a few hours. The spindle  34  including the outboard end portion  32  has a threaded opening  55  centered around its axis on its outboard end to accept the threaded stub shaft  26  in a threaded relationship. Preferably, the outer periphery of the outboard end portion  32  of the spindle  34  is surrounded by the flange  56  and or the locking plate  28  as it resides in the opening of the locking plate  28  and/or at least a portion of the flange  56  when the roll  6 ,  8  and its insert  52  is in place in the hub  9  on the spindle  34 . 
     Threaded into the flange  56  of the insert  52  from the outboard side are at least one and preferably two, three or more spaced apart shoulder bolts  57  having a threaded portion  58 , an unthreaded portion  59  having a diameter of slightly less than the width of the end portion  36  of the slots  29  in the locking plate  28  of the roll retainer A, and a head  60  having a diameter larger than the width of the end portion  36  of the slots  29 , but smaller than the width of the wide portion  35  of the slots  29 . The length of the unthreaded portion  59  of the shoulder bolts  57  should be slightly greater than the thickness of the locking plate  28 . To save time in changing the backup roll  8  and the blade roll  6 , it is preferred that all such rolls be equipped with the insert  52  and the shoulder bolts  57  secured tightly into the flange  56 , and into the hub  9  if desired, but of course, neither of these preferences or modifications are necessary to practice the present invention. Also, preferably, but not necessarily, all of the secured shoulder bolts  57  are spaced apart, preferably equally spaced apart, around a single radius of the axis of the opening  30  in the locking plate  28 , but obviously different arrangements will also work so long as the slots  29  in the locking plate  28  align with the shoulder bolts  57  when the stub shaft  26  is threaded into the opening  55  of the spindle  34 . 
     All parts of the roll retainer A, except for the thrust washers  46  and  50 , are preferably made from a strong material such as a stainless steel that will not corrode in the hot, wet environment. Many other materials can also be used such as other metals, alloys and fiber reinforced plastics. 
     To use the fast acting roll retainer A of the present invention, a new roll such as a backup roll  8  containing the insert  52  therein and having preferably three shoulder bolts  57  secured in the flange  56  is placed on the spindle  34 , preferably in a snug manner. The threaded end of the stub shaft  26  of the roll retainer A is then threaded into the threaded opening  55  of the spindle  34  at least several turns by turning or spinning the spinner  24  and handles  25 . Next, the locking plate  28  is rotated with one hand, preferably while holding the handles  25  with the other hand to prevent the stub shaft  26  from rotating, to align the wide portion  35  of the slots  29  with the heads  60  of the shoulder bolts  57 , and the stub shaft  26  is rotated into the opening  55  of the spindle  34  until at least hand tight using the handles  25 . Then, the spinner  24  is backed off about 5-180 degrees and the locking plate  28  is rotated to seat the end portion  36  of the slots  29  against the unthreaded portion  59  of the shoulder bolts  57 . Last, the spinner  24  is rotated to tighten the inboard face  38  of the locking plate  28  against the outboard face of the hub  9  and/or the flange  56  on the insert  52 , and finally, tightened by striking one of the handles  25  with a dead blow, such as by striking it with a lead-headed hammer or a hammer containing heavy pellets in the head portion. In the final tightening step the lubricated washer  46  enhances the relative movement of an inboard face of the spinner  24  to move while the exterior bottom surface  43  of the locking cup  40  remains fixed, i.e. does not rotate. The roll  6 , 8  is now in place and ready to operate. 
     When it is time to remove the roll  6  or  8  from the chopper  2 , one of the handles  25  is struck one or more dead blows to start backing the stub shaft  26  out of the hole  55  in the spindle  34 . As that happens the outboard face of the lock ring  48  pushes against the second lubricated thrust washer  50  which pushes against the interior bottom surface  45  of the locking cup  40 . Note that the lock ring  48  is fixed to, or integral with, the stub shaft  26 . The thrust washer  50  enhances the relative movement of the outboard face of the rotating lock ring  48  and the non-rotating interior bottom surface  45  of the locking cup  40  under stress. As the lock cup  40  is pushed in an outboard direction by the action of backing the stub shaft  26  out of the hole  55 , the insert  52  and the roll  6 , 8  is pulled loose from the spindle  34  by the outboard face  37  pushing against the heads  60  of the shoulder bolts  57 . Once the insert  52  has been broken loose on the spindle  34 , the spinner  24  is rotated in the other direction a few degrees by hand to loosen the locking plate  28  with respect to the heads  60  of the shoulder bolts  57 . While holding the spinner  24  from rotating, the locking plate  28  is rotated to move the heads  60  into the wide portion  35  of the slots  29  and then the spinner  24  is spun with the handles  25  to remove the stub shaft  26  from the opening  55  in the spindle  34  and the roll retainer A is removed. The roll  6 , 8  is now ready to be removed and replaced with a new or repaired roll  6 , 8 . 
     Using the roll retainer A of the present invention, a roll  6 , 8  on a chopper can be changed faster than was the experience with the roll retainer means of the prior art. Large wrenches or compressed air impact tools are not required. Instead only a dead blow hammer or device such as a lead hammer is needed and this makes the job go faster and easier. Also, since it is not necessary to strike the rolls to loosen them from the spindle when it is time to remove a roll, the rolls last longer. With each roll change, the roll retainer of the present invention saves at least about 30 seconds and typically more than that. With two rolls to be changed at each chopper rebuild the time savings are at least one minute. When this savings is cumulated over the period of a year with the typical number of choppers used and the typical blade life, the extra production gained is at least 100-186 hours and at least 1,000,000 pounds of additional product and at least 1,000,000 pounds of reduced scrap produced. This amounts to substantial marginal profit improvement. 
     When a different sizing is used causing more or less tackiness on the surface of the fiber, the angle at which the chopped fiber array leaves the backup roll  8  changes. This change in angle or direction of discharge with different products causes the fiber to sometimes strike the collecting or transporting device like a conveyor at less than an optimum location and some fiber misses and either falls on the floor or gets under the belt, the latter causing belt tracking problems and scrap which can contaminate the good product. The material falling on the floor creates a costly housekeeping problem and often ends up as scrap. These conditions are costly and undesirable. Also, when the chopped product being produced requires partial or complete drying, it is desirable to feed the product directly into an entrance to the dryer. To accomplish the latter it is necessary to change and adjust the angle of discharge of chopped fiber from the chopper. 
     FIGS. 2 and 2A show a preferred embodiment, B, according to the present invention for precisely changing the angle of discharge. Prior art choppers  2  typically rested on four feet  5  on the floor. In the preferred embodiment of the present invention, the chopper  2  rests instead on one or more brackets  22  pivotly attached to one or more legs  21  at or near one bottom edge of one side of the chopper  2 , which legs are attached to a pedestal  64 , and brackets  63  connected to a lifting mechanism B that is also supported by the pedestal  64 . This arrangement allows the chopper to be tilted. This arrangement is accomplished with at least one, and preferably two, clevis type brackets  22  spaced apart and attached rigidly to a lower portion of one side of the chopper  2 . Each bracket  22  is pivotly attached to one leg  21  with the pin  23 . The leg or legs  21  are attached to the pedestal  64  in any suitable manner. 
     On the opposite side of the chopper  2  at least one, and preferably two spaced apart, larger clevis type brackets  63  are rigidly attached to a lower portion of the opposite side of the chopper, preferably at or near the bottom edge. Pivotly attached to each of the brackets  63  is a jack, preferably a screw jack  65 . A bottom end of a screw  67  of the screw jack  65  is attached in any known pivoting manner, such as with a pivoting bracket  70  attached to the top surface of the pedestal  64 . A semi-spherical depression in the top surface of pedastal with a ball on the bottom end of screw  67  would also be suitable. The pedestal  64  can be solid or can be a frame having an open center portion  74  as shown. 
     Preferably two screw jacks  65  are used and the two are tied together with a drive shaft  69  which is turned with a ratchet tool or hand crank (not shown) at a socket receiver  68 . This allows both screw jacks  65  to be adjusted to the same degree at the same time. A protective guard  72  is removably attached to the upstream end  66  of the chopper  2  to protect the screw jacks  65  and the screws  67  from fiber and sizing that would otherwise fall on the these items and interfere with their smooth operation. 
     In this embodiment the screw jacks  65  are on an upstream side  66  of the chopper  2  and the legs  21  are on the discharge side  68  of the chopper  2 , but the screw jacks  65  could be mounted on the discharge side  68  of the chopper  2  with the legs  21  and brackets  22  being mounted on the upstream side  66  of the chopper  2  when that configuration is needed to provide the desired result, or the same desired result in a more desirable manner. 
     FIG. 2 shows in phantom the chopper  2  tilted by lifting the upstream side  66  with the screw jacks  65  to cause the angle of discharge of chopped item  15  to be lowered in a direction closer to the pedestal  64 . Also, the chopper  2  can be operated normally in the position shown in phantom. Then the angle of discharge of the chopped items  15  can be raised in a direction away from the pedestal  64  by lowering the upstream side  66  of the chopper  2 , using the screw jacks  65 , until the angle of discharge of the chopped item  15  is acceptable. 
     As shown in FIGS. 5 and 6, lifting devices other than the screw jack  65  can be used in accordance with the present invention such as a fluid cylinder  73  powered by either a gas like air or a hydraulic fluid, or a simple mechanical jack like an automotive bumper jack  75 . Other types of lifting devices can also be used such as one or more overhead winches, chain-falls, fluid cylinders, etc. and off floor lifting devices such as one or more scissor jacks, inflatable bags, etc. 
     FIGS. 7 and 8 show a preferred frame  76  for mounting the chopper  2  upon to tilt the chopper according to the present invention. The frame  76  contains a square or rectangular framework  77  having a square or rectangular opening  79  therein in which is pivotly mounted a second framework  80  on an axle  82  that passes through the framework  77  and into or through the second framework  80  near one end of the second framework  80 . The framework  77  and the second framework  80  could be other shapes including other polyagonal shapes, U shaped, a circle or oval. Also, the second framework can be just two separate members with one end of each member attached to an axle  82  and the member attached to the bottom of the chopper frame or one member attached to the the chopper front plate and the other member attached to a chopper back plate. 
     Optional stops  84  can be attached on an opposite end of the second framework  80  to contact the top of the framework  77  when the top of the second framework  80  is level. Brackets  86  are attached in any suitable manner, preferably to the top of the framework  77 , in the embodiment shown in FIG. 7 near where the stops  84  contact the framework  77  for connecting the bottom ends of the screw  67  of the screw jacks  65  (See FIG.  8 ). The brackets could also obviously be placed on the bottom or one of the sides of the framework  77 . 
     The chopper  2  is preferably attached to the movable framework,  80  in the embodiment shown in FIGS. 7 and 8, in any suitable manner which will secure the chopper in a stable and safe manner. In the embodiment shown in FIGS. 7 and 8, threaded holes  83  are placed in at least two sides of the second framework  80  for attaching the bottom edges of the chopper  2  to the second framework  80 . The chopper need not be bolted to the frame but that is preferred. The chopper could simply sit on the second framework  80  and in such an embodiment, the chopper would be more secure if the top of the second framework  80  had depressions in its top surface for chopper feet  5  such as shown in FIG.  1 . The frame  76  also has legs  78  attached to the framework  77  for setting on the forming room floor and for spacing the bottom of the framework  77  from the floor so that a lift truck can get under the frame  76  and chopper  2  to lift and move the frame  76  and chopper  2 . 
     While the embodiment shown in FIGS. 7 and 8 show the chopper attached to the second framework  80  and legs  78  attached to the first or outer framework  77 , it is also workable to reverse this arrangement by placing the legs on the second framework  80  and attaching the chopper  2  to the first or outer framework  77 . In this latter configuration the brackets  63  would be located inside the chopper cabinet formed by the front plate  4 , the side plates  66  and  68  and a back plate, and the lifting devices  65  would also be inside the chopper  2  cabinet and would rest on the top face of the second framework  80 . 
     FIG. 9 shows in perspective an embodiment that is a modification of the embodiment shown in FIG.  7 . In this embodiment, the second framework  80  has been modified to make a U-shaped framework  88  to support the chopper  2 . Since the two legs of the U-shaped framework  88  are bolted to the front or back plate of the chopper  2  using threaded holes  83  in each of the legs of the U-shaped framework  88  as shown, this arrangement works well. It is also possible to flip the U-shaped framework so that the open end of the U is at the end of the frame  77  opposite the end supporting the screw jacks  65 . In this latter case the axle  82  passes through, or into, an end portion of each leg of the U-shaped framework  88 . 
     Using the embodiment shown in FIG. 9, and omitting the optional stops  84  (FIG. 7) and placing the brackets  63  higher on the chopper, the angle of discharge can be raised or lowered with the same embodiment since the free end of the second framework  80  nearest the screw jacks  65  can be both raised and/or lowered as the second framework  80  can be lowered through the opening  79  to below the first framework  77 . 
     FIG. 10 shows in perspective a still further embodiment which is another modification of the embodiment shown in FIG.  7 . In this embodiment, the inner frame  80  is replaced with a first chopper support member  89  and a second chopper member  90 . Each of the chopper support members  89 ,  90  are pivotly mounted or supported by the axle  82  passing into or through each of the chopper support members  89 ,  90  near one end. Each of the chopper support members  89 ,  90  contain threaded holes  83  for attachment to the front plate  4  and a back plate (not shown) of the chopper  2 . 
     The preferred embodiments of the invention and other embodiments of the invention are disclosed above with the broader concept of the invention. It will be obvious to the artisan in the appropriate art that modifications other than those disclosed above can be made to achieve the same results in substantially the same manner within the concept of the invention, and it is intended that these modifications are encompassed in the following in which we claim.