Abstract:
A rotary trimmer apparatus and signature trimming method are provided that enable operators to set a gap spacing between a rotating knife and an anvil at different predetermined sizes in an easy and accurate manner. The operator chooses the optimum knife/anvil spacing that produces a scissors-like cutting action on the particular type of signatures being trim cut and which does not cause premature knife dulling. The selected knife/anvil spacing is readily reproducable for future runs with the same operating conditions. This is true regardless of changes in the knife thickness as can be created by sharpening thereof, or knife replacement. For this purpose, a user operated control assembly including a control knob and calibrated indexer are provided. To keep the knife/anvil spacing at the set size during trim cutting operations, a temperature control system is employed that keeps axial expansion of the knife spindle shaft from reducing the gap size. In the preferred form, the temperature control system is a cooling system that uses a temperature controlled housing for the spindle shaft that maintains a substantially constant and relatively low operating temperature, e.g. 80° F., therein that is effective to avoid any significant axial shaft growth that would unduly reduce the knife/anvil gap size and cause less than high quality cuts to be generated.

Description:
FIELD OF THE INVENTION 
     The invention relates to an apparatus and method for trimming signatures and, more particularly, to a system for obtaining high quality, precision trim cuts of signatures. 
     BACKGROUND OF THE INVENTION 
     Post press signature finishing equipment including such items as folders, rotary trimmers, and various types of stackers, transporters and palletizers are regularly being required to handle greater rates of throughput as printing presses are continually being developed with increasingly fast operating speeds as otherwise high production speeds can be quickly lost post press. For rotary trimmers, this means that the knife needs to be able to maximize the number of cuts, e.g. 15-30 million trims, before requiring maintenance for sharpening or replacement of the cutting surfaces thereof. With high throughputs, trimmers undertake more cuts in a shorter period of time so that if the blade needed maintenance after a relatively few number of cuts there would be unduly frequent downtime for the production line due to the in-line rotary trimmer. This is especially undesirable if the knife starts creating low quality cuts in the middle of a press run requiring interruption of production for knife maintenance. 
     In rotary trimmers, proper setting of the clearance gap between the rotary knife and anvil is extremely important as that will in large part determine whether the trimmer generates high quality trims over a long knife life. Thus, maximizing knife life is of paramount concern because resharpening the knives is expensive, especially if it goes dull during a press run, as mentioned. Assuming the proper knife/anvil gap is set, they will cooperate with each other to cut or sever edge portions of the signatures with a scissors-like action generating clean, square cut surfaces. However, if this gap is too small or tight, the knife will quickly dull due to the excessive applied force at the cutting edges thereof. As opposed to a scissor-like severing action applied to the signatures, the dulling knife and anvil will exert more of a tearing or ripping action that generates fuzzy cut surfaces. On the other hand, if the gap is too large or loose, then the knife/anvil will not cut at all. Because the difference between a properly set knife and an improperly set knife can be the result of a change in the gap of only thousandths of an inch, setting of the knife/anvil gap needs to be a precise operation. 
     Currently, rotary knives of trimmers are usually adjusted by very low wage operators whose turnover rate generally is very high. A rough adjustment mechanism is provided to advance the knife toward a lower anvil that is mounted for some vertical overlap with the knife. The operator is supposed to select a feeler gauge with a thickness corresponding to the gap between the blade and anvil needed to generate high quality trim cuts for the particular sheet material to be trimmed. The operator carefully inserts the gauge into the cutting area between the knife and anvil and holds it there with one hand while reaching back with their other free hand to operate the adjustment mechanism for advancing the knife until the gauge is clamped between the knife and anvil. Then, using the adjustment mechanism the operator slightly backs up the knife just enough to allow them to free the gauge. 
     Of course, at this point the gap is necessarily larger than the gauge thickness so that already it is likely that there will be some quality concerns in cutting with the knife so set. Also, requiring the operator to insert the feeler gauge into the cutting area brings them dangerously close to cutting surfaces on the rotary knives increasing chances for injury. Moreover, as is apparent, this is an arduous procedure that frequently is just not done by low wage operators who instead try to eyeball the adjustment of the knife so that there is the correct gap between it and the anvil. 
     After this initial set-up, operators are instructed to let the rotary trimmer run for about fifteen minutes, and to then recheck the gap to determine whether the knife/anvil spacing has shifted due to thermal expansion of the knife assembly, and thus if the knife needs to be backed up to maintain the gap at its desired size. However, it has been found that it is very rare for operators to ever undertake this secondary check of the knife/anvil spacing especially since it is inefficient in that it requires the rotary trimming line to be shut down while the rechecking takes place. Since it is the usual case that the knife/anvil gap is not rechecked, it is much more likely that the knife life will be seriously compromised due to thermal expansion. 
     Directing ambient air into a shroud extending about the knife has been attempted to address the problem of excessive heat at the cutting edges which can cause the ink and varnish at the cut edges to smear and can also cause burning of the cut edges. However, this approach will not be satisfactory in avoiding the reduction in size of the knife/anvil gap during trim cutting operations as heat is also generated at other portions of the knife assembly beyond just at the knife head. 
     Manufacturers of rotary trimmers and the knives thereof want to be able to market their machines based on how many high quality trims one can expect to obtain before knife maintenance should occur. In this way, their customers can plan for knife maintenance to avoid generating excessive amounts of spoiled product, i.e. signatures with poorly cut surfaces by dull knives. In other words, customers want to be able to plan press runs so they will not be started with a knife that will need to be sharpened or replaced in the middle of the run, which also increases undesirable downtime, as previously discussed. 
     Certain known variables relating to the paper to be cut such as type, content, weight and thickness, for example, as well as operating speed of the trimmer can be factored in to allow manufactures to determine the knife life a customer can expect. However, the current situation where human operators are required to properly set-up the trimming machine as set forth earlier make such determinations virtually impossible as it has been found that significant inconsistencies in knife life and trim quality arise between different customers that cannot be attributed to differences in the other known variables. Of course, this makes sales of rotary trimmer knifes more difficult as very meaningful statements regarding knife life correlated to the known variables are hard to substantiate. Instead, very large ranges for knife life are specified, e.g. 15-30 million trim cuts, and even so, reaching this range still depends on proper set-up of the machine including the knife/anvil gap spacing. 
     Accordingly, a need for a rotary trimmer apparatus and signature trimming method exists that provides precision adjustments of the knife/anvil gap to be made in an accurate, easy and efficient manner. Further, a rotary trimmer apparatus and method that allow for high quality trims to be consistently made over long knife lives would be desirable. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a rotary trimmer apparatus and signature trimming method are provided that allow the gap spacing between a rotary knife and anvil to be easily and precisely set prior to operation of the apparatus with the knife staying sharp for a maximum number of trims to generate high quality cuts therewith, without the need to recheck the set knife/anvil spacing as previously required. To this end, the present invention allows an operator to incrementally shift the rotary knife to one of the plurality of predetermined spaced positions relative to the anvil without the need for separate special tools or the like. Further, during operation, the knife is maintained at the selected position via a temperature control system for a rotary spindle shaft to which the knife is mounted. The temperature control system maintains the temperature of the rotating shaft substantially constant between its temperature during set-up to its temperature during trim cutting operations. In this manner, axial shifting of the knife due to temperature changes of the shaft, especially thermal expansion of the spindle shaft during cutting operations is substantially obviated, thus keeping the knife at its selected spaced position relative to the anvil ensuring that the knife does not prematurely dull and/or generate less than high quality precision cuts. Accordingly, by way of the present invention, manufacturers of these trimmers and rotary knives will be able to more precisely determine their useful life as a function of various known operating conditions, e.g. paper type, number of folds in the signature books, and operating speeds, as the knife is readily accurately shifted to the desired spaced position relative to the anvil and is maintained thereat, even during high throughput cutting operations of the rotary trimmer, e.g. up to 110,000 signatures per hour. 
     It has been found that unwanted linear shifting of the knife due to thermal expansion during trimmer operations occurs primarily because of the expansion that occurs at the knife spindle shaft which shifts the knife closer toward the anvil along the shaft axis increasing the forces at the cutting edges of the knife which, in turn, prematurely dulls these edges shortening knife life. Accordingly, the temperature control system herein keeps the temperature of the shaft substantially constant from when the knife/anvil gap spacing is set to its temperature during trim cutting operations. Although the preferred mode of operation is by directing a cooling medium, e.g. cool air, into heat transfer relation with the spindle shaft, it is also contemplated the shaft could be subjected to high heat so that when the knife position is set, the shaft is at a pre-heated high temperature and subsequent heat generation in the shaft bearings will not cause a temperature rise in the shaft. Alternatively, such as where spindle shafts are open as discussed further herein, high volumes of ambient air can be discharged at the shaft so that the shaft does not experience a significant temperature rise during trim cutting operations. The temperature control system herein in whichever form that is employed is effective to keep the shaft at a substantially constant temperature during set-up and trim cutting operations. 
     Herein, substantially constant temperature of the spindle shaft means the system keeps any temperature differential that develops to a minimum so that any knife shifting due to this differential will be so minor as to not affect the quality of the cuts obtained or be a detriment to the life of the knife. The differential that is acceptable depends on several factors, such as the length of the shaft from where it is held in its forwardmost bearing to the end of the knife and the shaft material, as well as the characteristics of the signature being trim cut. 
     By way of example and not limitation, to keep shaft expansion to an amount that is not detrimental to trim quality and knife life such as 0.0005 inch and with the spindle shaft being of alloy steel material and having a length of 2.0 inches from bearing to knife end, the temperature differential is preferably kept to approximately 15° F. by the temperature control system herein. The maximum amount of knife shifting that is tolerable is approximately 0.001 inch. In this instance, the temperature differential can be approximately 30° F. To obtain the allowable temperature differential for a particular amount of linear expansion that is tolerable, this amount of linear expansion of the shaft is divided by the product of the operable shaft length, in this instance 2.0 inch, and the coefficient of linear expansion per linear inch, e.g. 0.0000160 in/°F. for an alloy steel knife spindle shaft. 
     With the preferred cooling of the shaft provided by the present temperature control system, thermal expansion of the knife spindle assembly is minimized thus maximizing the number of trims obtained with the knife that are of a consistently high quality, and avoiding the need to recheck the knife/anvil spacing after running of the trimmer apparatus as was previously required. More particularly, the present preferred cooling system can include a temperature controlled housing or knife spindle block. The spindle block includes a chamber through which the knife spindle shaft extends. Preferably, air is used as the cooling medium and is fed into the knife spindle block, circulates within the internal chamber thereof, and then exits the block to keep the internal space of the housing at a constant, relatively cool operating temperature, e.g. 80° F., at which significant axial shaft expansion will not occur. In this regard, it is preferred that the air be cooled before being fed to the spindle block to below room temperature to improve the cooling capacity of the system. 
     After exiting the knife spindle block, the cool air can be directed at the periphery of the knife via an adjustable hose with an outlet nozzle that is pointed at the knife edge of the trimming knife such that the cool air impinges thereon. Thus, the present cooling system can cool both the knife spindle and trimming knife simultaneously using a common cool air source. In addition, focusing the cool air directly at the knife cutting edge is much more effective in keeping the heat generation thereat to a minimum versus simply supplying a knife shroud with ambient air flow therethrough. Where the knife is of a solid body design with an integral serrated cutting edge at its periphery versus having a plurality of removable segments, the temperature rise at the cutting edge is more significant, e.g. 170° versus 120°, thus rendering the auxiliary cooling of the knife edge more important in achieving a large number high quality trim cuts therewith. Even with the segmented knife, the auxiliary cooling herein is beneficial in reducing heat build-up at the cutting edges and the low quality product and product spoilage this can create. 
     As previously mentioned, the present rotary trimmer apparatus allows an operator to very easily and accurately position the knife relative to the anvil. For this purpose, the rotary trimmer apparatus preferably has a control knob that is calibrated for different predetermined spaced positions of the knife relative to the fixed anvil so that turning of the knob indexes the knife between the different positions. This allows an operator to determine which spacing of the knife and anvil generates the best cuts for particular operating conditions and so that when these operating conditions are repeated, they will easily be able to obtain the same knife/anvil spacing and reproduce the high quality cuts they need. 
     The control knob is remote from the cutting area between the knife and anvil and does not require the use of a feeler gauge or the like so that the operator can remain at the remote position of the control knob during precision setting of the knife position relative to the anvil. Accordingly, no longer is there a need for an operator to get near the cutting area and endanger themselves with the sharp cutting edges of the rotary knife as could previously occur when using the feeler gauge. 
     For precision shifting of the knife, turning of the control knob rotates a threaded actuator shaft that is operable to translate the spindle block carrying the spindle and knife therewith. An internally threaded member fixed to the spindle block cooperates with the threads on the actuator shaft so that turning of the control knob causes the spindle block to translate on a slide fixture therefor. However, with normal thread tolerances, there will be a backlash after shifting of the spindle block that is unacceptable for the precision movements of the knife needed herein, i.e. on the order of thousandths of an inch. While obtaining precision ground threads is possible, manufacture of these types of threads would undesirably increase the cost of the present trimmer apparatus. 
     Accordingly, the internally threaded member attached to the spindle block is preferably in the form of a take-up member that is split into opposing portions that are adjustable relative to each other. Thus, the take-up member can be provided with internal threads of a normal tolerance while allowing the portions thereof to be adjusted to take up the slack between the threads of the take-up member portions and the actuator shaft threads while still allowing an operator to rotate the shaft for shifting of the spindle block without seizing. In this manner, the present adjustment mechanism provides precision movements of the spindle block without necessitating the increased cost associated with high precision ground threads. A further advantage of the take-up member is that it can be of a softer material than the actuator shaft, e.g. brass versus steel. Even as the brass take-up member wears, the take-up member portions can be adjusted to accommodate for the extra play in the threads the wear creates thus maintaining the precision movements provided by the present adjustment mechanism over time. 
     In another aspect of the present invention, a method of maximizing the knife life in a rotary trimmer apparatus is provided. The method includes providing an adjustable rotary knife having at least one peripheral cutting surface and a rotary anvil to form a signature cutting area, adjusting the knife to one of a plurality of predetermined known spacings from the anvil by a user at a position remote from the cutting area, running the signatures through the cutting area and cutting edge portions off therefrom, and keeping thermal expansion of a rotary spindle shaft carrying the rotary knife to a minimum to maintain the knife at the predetermined spacing from the anvil during cutting operations so that the peripheral cutting surface of the knife stays sharp over a maximum number of cuts therewith to generate square cut surfaces of the signatures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic perspective view of a rotary trimmer apparatus including two trimming units for trim cutting of edge portions from signatures conveyed in a shingled stream through the trimming units; 
     FIG. 2 is an elevational view of a cutting apparatus for the trimming units in accordance with the present invention showing a rotary knife and a lower rotary anvil forming a signature cutting area therebetween and including a cooling system for a spindle shaft mounting the knife and a user operated control assembly for precision indexing of the knife to different spaced positions relative to the anvil; 
     FIG. 3 is an enlarged fragmentary elevational view of the cutting area formed at the overlap between the rotary knife and anvil; 
     FIG. 4 is a perspective view of the rotary knife and anvil during operation of the rotary trimmer apparatus showing edge portions of the shingled signatures being severed and the knife including a plurality of removably attached cutting segments; 
     FIG. 5 is a front elevational view of the rotary knife and anvil as shown in FIG.  2 . showing a solid body knife having a serrated peripheral cutting edge; 
     FIG. 6 is a plan view of the cutting apparatus of FIG. 2 showing a control knob for turning an actuator shaft of the control assembly, a take-up member on the actuator shaft attached to a spindle block, a cool air source of the knife spindle cooling system that supplies cool air to the spindle block and an auxiliary cooling line that directs cool air at the knife peripheral cutting edge; 
     FIG. 7 is a cross-sectional view of the cutting apparatus taken along line  7 — 7  of FIG. 5 showing an internal space in the spindle block housing in which the knife spindle extends and an indexing mechanism including a plunger and apertured collar that are calibrated to cooperate to identify the different predetermined spaced positions of the knife relative to the anvil obtained by turning the control knob; 
     FIG. 8 is an enlarged fragmentary sectional view of a scraper mechanism for the anvil including a scraper that engages the anvil and a biasing member for the scraper to urge it into contact with the anvil; 
     FIG. 9 is a perspective view of the user operated control assembly including the control knob, the plunger and apertured collar, and the take-up member on the actuator shaft; 
     FIG. 10 is a rear elevational view of the cutting apparatus showing a releasable lock in the form of screw clamps having lever operating arms for the apertured collar and the slide block; 
     FIG. 11 is a cross-sectional view taken along line  11 — 11  of FIG. 10 showing the control knob, the plunger and apertured collar, and the take-up member on the actuator shaft; 
     FIG. 12 is an enlarged fragmentary view partially in section of the plunger and apertured collar; 
     FIG. 13 is an enlarged perspective view of the take-up member showing opposing portions thereof and an adjustment member therefor; 
     FIG. 14 is an enlarged fragmentary sectional view of the take-up member on the actuator shaft showing the threaded engagement therebetween with the take-up member adjusted to take up the slack in the threads; 
     FIG. 15 is an enlarged cross-sectional view of the slidable mounting of the spindle block on a fixture base including the releasable locking clamp therefor; 
     FIG. 16 is a perspective view of a mounting plate for the user operated control assembly; 
     FIG. 17A is a perspective view of the apertured collar; 
     FIG. 17B is a front elevational view of the collar of FIG. 17A showing two sets of apertures thereof; 
     FIG. 18 is a elevational view of a mylar label including indicia that are to be aligned with the apertures of the collar with the label adhered thereto; 
     FIG. 19 is a side-elevational view of a spacer member for the releasable lock of the collar member; 
     FIGS. 20A-C are various views of the take-up member; and 
     FIG. 21 is a schematic view of a layout for post-press in-line finishing equipment including the rotary trimmer apparatus that can incorporate the cutting apparatus of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1, a rotary trimmer apparatus  10  for incorporating a signature cutting or trimming apparatus  12  (FIG. 2) in accordance with the present invention is shown. The rotary trimmer apparatus  10  can take on a variety of configurations including the illustrated apparatus  10  having a pair of trimming units  14  that are at a 90° orientation relative to each other so as to allow signatures  16  to have edge portions  18  cut off therefrom that also extend at 90° relative to each other. For transporting the signature  16 , the rotary trimmer apparatus  10  has a frame  20  that supports a conveying system  22  on which a stream of signatures  16  is carried downstream. The signatures  16  can be folded and in overlapping orientation with adjacent signatures to provide a shingled stream of the signatures or books  16  that are to be trimmed as they are transported through the trimming units  14 . 
     The trimming units  14  each have at least a single set  23  of an upper knife  24  and a lower anvil  26  which are preferable mounted for rotation via respective spindle shafts  28  and  30  therefor. It is also contemplated that the position of the knife  24  and anvil  26  can be substantially reversed so the knife  24  is below the anvil  26 . Also, the anvil  26  need not necessarily be rotated; however, for most types of paper and folded books  16 , rotation of the anvil  26  generates the best cutting action and thus is desired. As shown in FIG. 1, opposing knife/anvil sets  23  can be provided on either side of the conveyor  22  for trimming of opposite parallel edge portions  18  from the signature books  16 . The spindle shafts  28  and  30  are part of a rotary drive system including motors and transmission belting (not shown) that rotate the shafts in opposite directions to cause the knife  24  and anvil  26  to similarly rotate and cut signatures  16  as they pass through a cutting area  32  formed therebetween. In this regard, the knife  24  and anvil  26  overlap each other at their lower end  34  and upper end  36 , respectively, with a very small gap  37  therebetween, as best seen in FIGS. 2 and 3. 
     The spacing of this gap  37  transverse to the travel direction  48  of the signature stream in large part determines the quality of the scissors-like cutting action obtained between the rotating knife  24  and anvil  26 , as previously discussed. For this purpose, the present cutting apparatus  12  preferably includes both an adjustment mount, generally designated  38 , that allows for precision shifting of the knife  24  to a plurality of predetermined spaced positions relative to the anvil  26  and a temperature control system, generally designated  40  (FIG.  6 ), that, in the preferred and illustrated form thereof, is operable to keep thermal expansion of the knife spindle shaft  28  to a minimum during cutting operations, although each of the adjustment mount  38  and the temperature control system  40  can be utilized in the cutting apparatus  12  independent of the other and still substantially obtain the advantages for high quality precision trimming that each provides. 
     One significant cause of problems during trim cutting operations that has been identified herein is heat generation in the knife spindle assembly including the spindle shaft  28 , and the temperature differential this creates between the temperature of the material of the shaft as set before cutting operations, and the temperature of the shaft material with the shaft undergoing high rpm&#39;s, e.g. 2000, during cutting operations. In prior rotary trimming machines, after the usual rough setting of the knife position relative to the anvil  26  to the desired gap spacing  37  therebetween, the operator needed to go back after running of the machine to make sure a reduction in the size of the gap  37  had not occurred. Any such reduction can prematurely dull the peripheral cutting edge  42  of the knife so that the number of high quality trims generated thereby is not maximized. Herein, the temperature control system  40  is focused on keeping the heat generated at the knife spindle shaft  28  to a minimum. 
     What has been found is that when there are large forces generated on the knife cutting edge  42 , such as when thick signature books  16  are being trimmed or the gap  37  is smaller than it should be, there is greater loading on the knife spindle shaft bearings  43 , which, in turn, creates more friction in the bearings and more heat generated on the shaft  28 . Heat generation in the spindle shaft  28  causes it to grow in the axial direction  44  along its shaft axis  46  toward the anvil  26  which is transverse to the downstream travel direction  48  of the signature books  16  on the trimmer apparatus conveyor system  22  thus reducing the gap  37 . Such thermal expansion of the spindle shaft  28  is believed to account for the majority of the reduction in the knife/anvil gap  37  that occurs during trim cutting operations. As is apparent, the problem of thermal expansion is cumulative and can quickly dull cutting edges  42 , especially if sufficient to cause the knife to engage the anvil during trim cutting operations. 
     Accordingly and has been mentioned, the preferred temperature control system  40  herein is adapted to minimize the thermal expansion of the spindle shaft  28 . In the illustrated and preferred form, the temperature control system  40  includes a temperature controlled housing  48  having an internal cavity or space  50  in which the shaft  28  extends and into which cooling medium can be directed into heat transfer relation with the knife shaft  28  to keep it from thermally expanding and changing the gap spacing  37  between the knife  24  and anvil  26  during trimming operations. Alternatively, where the spindle shaft  28  is not disposed in a housing  48 , the cooling medium can be simply discharged directly at the open shaft  28 . While the cooling medium can be air that is cooled below ambient as described more fully hereinafter, it is also possible for this medium to simply be ambient air, of course recognizing that this would necessitate higher rates and volumes of such air discharged into heat transfer relation with the shaft versus those required for cooled air. 
     More particularly, the housing  48  can be a spindle block similar to prior spindle blocks modified to including porting  52  for a cooling medium supply line  54 , as shown in FIG.  6 . The supply line  54  directs cooling medium from a source  56  therefor into the housing internal space  50 . The present temperature control system  40  preferably uses air as the cooling medium with the air also having preferably been reduced to a temperature below ambient temperature, e.g. approximately 50° F. Air as the cooling medium is preferred due to its low cost, ready availability and environmental friendliness. With cool air being supplied into the spindle block housing space  50 , the temperature of the spindle shaft  28  can be kept substantially stable during trim cutting operations such as at a constant 80° F., for example, at which temperature the shaft  28  will undergo little, if any, thermal expansion along its axis  46  that would negatively affect the knife/anvil gap spacing  37  in terms of obtaining high quality cuts therewith, as previously has been described. 
     In the preferred and illustrated form, the temperature control system  40  also provides for cooling of the rotary knife  24  that is focused at the area where it is needed most; that is, the temperature control system  40  also directs cool air at the knife peripheral knife cutting edge  42 . This is of particular importance where the knife  24  is of a solid body design such as shown in FIG. 5 with the cutting edge  42  being serrated to form a large number of cutting teeth  58  integral with the knife body and extending around the periphery thereof. With these type of solid body knives versus the knives  25  shown in FIG. 4 that have a plurality of segments  60  each with a cutting edge  62  thereof, as described in applicant&#39;s assignees U.S. Pat. No. 4,840,098, there is a significant difference in the temperature rise that occurs during cutting operations. The segments  60  are of a very hard material such as a tungsten carbide material. With solid body knives  24 , the temperature can reach approximately 180° F. during trim cutting operations while with the segmented knife  25  operating temperatures reach only approximately 120° F. It is believed that this is primarily due to the increase in the amount of cutting edge surfaces provided with the serrated cutting edge  42  of the solid body knife  24  versus the cutting edges  62  of the segmented knife  25  and the lack of heat dissipating surfaces on the solid body knife  24  as compared to those provided by the segments  60  of the knife  25 . 
     Accordingly, the spindle block housing  48  is also ported at  64  to provide an outlet for the cool air fed to the internal cavity  50  via supply line  54 . At the outlet port  64 , a flexible air line or hose  66  is attached, as best seen in FIG.  6 . The line  66  includes an outlet nozzle  68  with the line being flexible yet capable of retaining its flexed orientation so as to allow an operator to manipulate the line  66  to orient the nozzle  68  for directing cool air taken from the housing internal space  50  toward the knife serrated cutting edge  42 . In this way, the temperature control system  40  keeps the heat generated at the cutting edge  42  during trim cutting operations to a minimum. 
     For generating cool air, the source  56  can include a vortex tube  70  utilizing technology similar to that disclosed in U.S. Pat. No. 1,952,281, which is incorporated by reference herein. Utilizing a vortex tube  70  allows a feed line  72  to be attached to a shop air source for utilizing pressurized ambient temperature air, e.g. 90 psi in the range of approximately 50-70° F., with the tube  70  creating two streams of air therein including a hotter outer stream that is vented and a cooler inner stream that is fed to the supply line  54  for being directed into the spindle block housing internal space  50 . As is apparent, the vortex tube  70  provides an inexpensive way for the present temperature control system  40  to provide the spindle block housing  48  with cool air. 
     Turning next to the precision adjustment mount  38 , reference will be initially had to FIGS. 9-11 which show a user operated control assembly, generally designated  82 , thereof. Similar to the temperature control system  40  that was retrofittable to prior rotary trimmer machines having a spindle block, the control assembly  82  can be retrofit by attaching it to the spindle block housing  48 , as will be described more fully hereinafter. The user operated control assembly  82  allows an operator to precisely control the position to which they shift the knife  24  relative to the anvil  26  so that the gap spacing  37  therebetween is known to the operator. As this control assembly  82  is mounted at the rear end portion  84  of the spindle shaft housing  48  and the operator need only turn a control knob  86  and utilize an indexing mechanism  88  adjacent the knob  86  to effect incremental shifting of the knife  24  to form predetermined known gap spacings  37  with the anvil  26 , the operator will be at a position remote from the cutting area  32  when adjusting the position of the knife  24  with the present user operated control assembly  82 . In this way, the control assembly  82  herein substantially obviates the safety concerns posed by the prior adjustment techniques that require an operator to insert a gauge in the cutting area  32 , as previously described. 
     More specifically, the control knob  86  operates a screw drive system  89  for the spindle block  48  by way of its attachment to an actuator shaft  90  as by fastener  92  at one end of the shaft  90  so that turning of the control knob  86  causes the actuator shaft  90  to rotate. At its opposite end, the actuator shaft  90  threadably drives the spindle block  48  for translation via internally threaded member  94  secured to the rear end portion  84  of the spindle block housing  48 . For this purpose, the member  94  includes a pair of fastener receiving through holes  96  and  98  on either side of internally threaded bore  100  with the apertures  96  and  98  aligned with corresponding threaded apertures (not shown) in the spindle block rear end  84  and the bore  100  aligned with a recessed bore  102  in the spindle block rear end portion  84 . 
     As mentioned, the control assembly  82  includes an adjacent indexing mechanism  88  that is disposed between the control knob  86  and a support plate  104  for the actuator shaft  90 , as can be seen in FIG.  7 . The plate  104  rotatably supports the actuator shaft  90  extending through a central bore  106  formed in vertical wall portion  108  thereof, as shown in FIG. 16. A bushing  110  is press-fit in the vertical wall portion bore  106  for rotatable supporting the actuator shaft  90 . 
     Continuing reference to FIG. 7, the indexing mechanism  88  includes an indexing collar  112  that is mounted on the actuator shaft  90  between the control knob  86  and the support vertical wall portion  108 . A retainer member  113  is mounted at a predetermined axial position along the shaft  90  behind the wall portion  108  to capture the collar  112  between the support plate  104  and knob  86  against axial shifting on the shaft  90 . 
     As best seen in FIGS. 17A and 17B, the collar  112  includes a large diameter portion  114  having calibrated apertures  116  formed therein. These apertures  116  cooperate with a plunger assembly  118  so that a user has an indication of when they have reached a certain predetermined spacing  37  of the knife  24  from the anvil  26 . 
     More particularly, the support plate  104  includes an upper rearwardly extending overhang portion  120  to which the plunger assembly  118  is mounted. The upper overhang portion is situated above the indexing collar  112 , and particularly apertured portion  114  thereof, and has a vertical through aperture  122  in which plunger shaft  124  is biased downwardly by spring member  126 , as best seen in FIG.  12 . Accordingly, when the indexing collar  112  is rotated such that one of the apertures  116  is brought into alignment with the through aperture  122 , the plunger shaft  124  will be biased so that its lower end  124   a  projects into the aligned aperture  116  to arrest further turning of the collar  112 , and in this way the operator will know that they are at the indicated spaced position  37  for the knife  24  and anvil  26 , as discussed further hereinafter. If the operator wants to continue to shift the knife  24  relative to the anvil  26 , they pull on upper knob  128  of the plunger assembly  118  so that the plunger shaft lower end  124   a  clears the aligned aperture  116  allowing the collar  112  along with the actuator shaft  90  to be turned. 
     The indexing collar  112  is also provided with an integral smaller diameter portion  129  with both the portions  114  and  129  having aligned central through openings to define a through bore  130  for the collar  112  through which the actuator shaft  90  extends. The collar  112  is oriented on the shaft  90  so that the small diameter portion  129  projects rearwardly and is disposed between the control knob  86  and the large diameter portion  114 . Accordingly, there is an annular surface  132  on the large diameter portion  114  that faces the operator as they are turning the control knob  86 . To this annular surface  132 , a ring label member  134  is adhered. The label member  134  can have a self-adhesive backing thereon and is provided with indicia  136  that when adhered to the annular surface  132  are aligned with the apertures  116  to allow an operator to read at which knife/anvil gap spacing  37  they are set. As shown, there are two sets  138   a  and  138   b  of apertures  116  with the aperture set  138   a  being adapted for a fine knife/anvil spacing size adjustments and the aperture set  138   b  adapted for coarser knife/anvil spacing size adjustments. 
     By having a number of different predetermined knife/anvil spacings  37  that an operator can select, the operator has significant flexibility in choosing the spacing  37  that provides the highest quality of cuts given the type of signatures  16 , e.g. paperweight, thickness, number of folds, etc., being run and the anticipated operating speed of the trimmer apparatus  10 . In addition, the operator can either make fine or course adjustments of the spacing  37 . By way of example and not limitation, the apertures  116  of the aperture set  138   a  can be calibrated so that shifting of the knife  24  is at increments of 0.0015 inch, while the apertures  116  of the set  138   b  can be calibrated so that shifting of the knife  24  is at increments of 0.002 inch. For this purpose, the apertures  116  of aperture set  138   a  are angularly spaced at 13.5° intervals from each other, and the apertures  116  of the set  138   b  are angularly spaced at 18° from each other. 
     For setting of the knife/anvil spacing  37  utilizing the control assembly  82 , the zero position of the knife/anvil set  23  needs to be initially set. In other words, the position at which the knife  24  is in engagement with the anvil  26  is to be the starting point for making the predetermined incremental adjustments to the spacing  37 . To do this, the collar  112  is allowed to rotate relative to the actuator shaft  90  by the provision of a narrow slot  140  in the small diameter portion  129  of the collar  112  that extends normal to the bore  130 . The slot  140  does not extend all the way through the entire diameter of the portion  129 . As can be seen best in FIG. 17A, the slot space  140  is very narrow, and increases the diameter of the bore  130  just enough to allow it to be in a clearance fit with the actuator shaft  90  extending therethrough. This allows an operator to turn the collar  112  on the shaft  90  until the zero position aperture  116   a  in aperture set  138   a  or aperture  116   b  in aperture set  138   b  is aligned with the plunger shaft  124  for receipt thereof. The control knob  86  is then turned with the collar  112  held against rotation by the plunger shaft  124  to advance the knife  24  into engagement with the anvil  26 . 
     By first setting the zero position of the collar  112  before operation of the control knob  86 , unintended rotation of the shaft  90  by turning of the collar  112  as by its frictional engagement with the shaft  90  will not occur. This ensures that the knife  24  will stay engaged with the anvil  26  during the zero position setting operation. Also, this zero position setting procedure where the shaft  90  is rotated with the collar  112  held in place, renders thickness changes in the knife  24  such as due to sharpening or use of different types or styles of knives irrelevant. Whatever the knife thickness may be, the knife  24  will be in engagement with the anvil  26  at the zero set position and from which the incremental adjustments to the knife/anvil gap spacing  37  will be made, as described further below. 
     After setting of the zero position, a releasable lock in the form of a screw clamp  142  is then operated to lock the collar  112  onto the actuator shaft  90  so that subsequent rotations thereof rotate the collar  112  therewith. For this purpose, a transverse counter-bore  142  is formed in the collar portion  129  with the bore  142  spanning the slot spacing  140 , as shown in FIG.  17 B. The bore  142  includes an enlarged counter recess  144  in which a spacer  146  (FIG. 19) is held. The spacer  146  is preferably cylindrical to allow a threaded shaft (not shown) of the screw clamp  141  to extend therethrough and for being threaded to a small diameter tapped bore section  148  on the opposite side of the slot  140  relative to the bore opening  144 . 
     Accordingly, rotation of the screw clamp  141  via lever operating arm  150  thereof in a tightening direction causes the space provided by the slot  140  to be taken up or reduced with the surfaces of the collar bore  130  tightly engaged on the portion of the actuator shaft  90  extending therethrough. With the lock  141  in its locked condition, the collar  112  will now rotate with the shaft  90  as the operator turns the control knob  86  to incrementally adjust the position of the knife  24  relative to the anvil  26  away from the zero position. As shown in FIG. 18, the mylar label  134  can include arrow indicia  152  showing the operator which way to turn the knob to move the knife  24  toward or away from the anvil  26 . As the operator turns the knob  86 , they will also have lifted the plunger shaft  124  so that its lower end  124   a  clears the zero aperture  116   a  or  116   b,  as previously discussed. 
     As previously mentioned, the member  94  is fixed to the spindle block housing  48  at the rear end portion  84  thereof and it cooperates with the actuator shaft  90  to provide the screw drive system  89  for precision shifting of the knife  24 . The bore  100  of the member  94  is provided with internal threads  152  that mate with external threads  154  on actuator shaft end  156 , as best seen in FIG.  14 . The shaft end  156  projects forwardly from the member  94  and into recessed bore  102  formed in the spindle block rear end portion  84 , as previously described. As shown, the recessed bore  102  is formed with sufficient clearance so that the shaft end  156  can translate therein as the shaft  90  rotates. 
     One of the problems with utilizing a screw drive system for the precision shifting of the knife  24  is that with threads of a normal tolerance sizing, there will be play between the threads  152  and  154  that creates backlash after the knife  24  has been shifted to the desired gap spacing  37  with the anvil  26 . This backlash is unacceptable for precision trim cutting as it causes the gap spacing  37  between the knife  24  and anvil  26  to change and can make the difference between a high and a low quality trim cut on the signatures  16 . Normal tolerance on threads is of the order of a couple of thousandths of an inch. While that appears small, herein the knife  24  is to be incrementally moved between the various spaced predetermined positions on the order of 0.0015 inch or 0.002 inch, as previously described. Accordingly, the normal play for threads is not acceptable. 
     Thus, the member  94  is formed as a take-up member with adjustable portions  158  and  160  thereof each having the threads  152 . These adjustable portions  158  and  160  are axially spaced from each other by a small gap  162  machined into the take-up member  94 . This gap  162  is adjustable so as to allow the member  94  to take up the play between the threads  152  and  154 . 
     More specifically, an adjustment member in the form of a threaded set screw  164  can be threaded through small threaded bore  166  in the member portion  158 . To increase the gap size  162  thus placing the members  158  and  160  in tension as indicated by arrows  168  in FIG. 14, the adjustment screw  164  is threaded until its distal end  166  abuts against rearwardly facing wall  160   a  of the take-up member portion  160 . Continued turning of the adjustment screw  164  pushes the portions  158  and  160  apart from each other widening the gap  162  and taking up the play in the threads  152  and  154 . The amount of tension on the threads  152  and  154  can be fine-tuned so as to allow threads  152  and  154  to rotate relative to each other without seizing while still substantially eliminating the backlash problems associated with a normal loose tolerance sizing of the threads  152  and  154 . In this way, the take-up member  94  herein avoids the need to provide precision ground threads and the high expense associated therewith while still providing for precision positioning of the knife  24  relative to the anvil  26  without the aforedescribed backlash problems. 
     The take-up member  94  can be of a softer material than the preferred hardened steel actuator shaft  90  such as brass so as to minimize seizing between the threads  152  and  154 . With repeated usage the softer brass take-up member  94  may start to wear; however, the wear can be compensated for by simply tightening the set screw  164  to take-up any additional play in the threads  152  and  154  created by the wear of the take-up member material. 
     Referring next to FIG. 15, there is shown the slide mounting of the spindle block  48  to allow it to undergo translation in the fore and aft direction  44  when the control knob  86  is turned. Slide mount  170  includes a base plate or fixture  172  and a gib portion  174  at the lower end of the spindle block  48 . The fixture plate  172  and gib portion  174  can have a dovetail fit with each other. In this regard, the fixture plate  172  includes undercut side portions  176  and  178  on either side of the gib portion  174  which has inclined surfaces  180  and  182  in close confronting relation the facing surfaces  176   a  and  178   a  of the respective fixture plate side portions  176  and  178  to provide secure guiding of the spindle block  48  as it slides on the fixture plate  172 . 
     Continuing reference to FIG. 15, a releasable lock in the form of a screw clamp  184  is provided for either locking the spindle block  48  in fixed position relative to the fixture plate  172  or releasing it for translation thereon as earlier described. The screw clamp  184  is similar to the index collar screw clamp  141  and includes an operating lever  186  for turning a threaded shaft  188  attached thereto. The fixture plate  172  has a threaded through bore  190  formed in the plate side portion  178  and in which the shaft is received with the bore  190  opening to a notched area  192  formed in the gib surface  182 . The notched area  192  extends for a sufficient distance in the axial direction  44  to allow the necessary shifting of the spindle block  48  in that same direction. 
     As shown in FIG. 15, the screw clamp  184  is in its unlocked condition which allows an operator to turn the control knob  86  as they lift up on the plunger assembly knob  128 . Once the plunger shaft  124  clicks into the aperture  116  corresponding to the desired knife/anvil spacing  37 , the operator turns the operating lever  186  to advance the shaft  188  through the bore  190  until the distal shaft end  194  engages and presses against a flat surface  196  of the notched area  192 . This pressing engagement of the shaft end  194  and surface  196  will tightly push the surfaces  176   a  and  180  of the fixture plate  172  and spindle block gib portion  174 , respectively, against each other causing binding and locking the spindle block  48  against further axial movement in the direction  44  thus fixing the knife/anvil spacing  37  at the selected size. 
     Referring next to FIG. 8, a scraper mechanism  198  is shown for keeping the rotary anvil  26 , and particularly the rear disk face  200  thereof, clean and free of debris that might collect thereon during cutting operations. It is this rear disk face  200  that cooperates with the cutting edges  42  or  62  of the rotary knives  24  or  25  to generate the scissors-like cutting action on the signatures  16 . The disk face  200  projects radially out from the disk body  202  to provide sufficient clearance for the necessary vertical overlap between the cutting edges  42  or  62  and the disk face  200  for proper scissors cutting of the signature  16 . 
     The scraper mechanism  198  is disposed at the lower end  204  of the anvil  26  opposite the upper end  36  thereof and remote from the cutting area  23 . Debris such as ink, varnish and glue from the signatures may adhere to the disk face  200  such as due to the heat generated during cutting operations. This debris will cause an effective reduction in the size of the gap spacing  37  and can lead to premature wear of the knife edges  42  or  62 . Accordingly, the scraper mechanism  198  is advantageous in that it maintains the set clearance gap  37  between the knife  24  or  25  and anvil  26 . 
     More specifically, the scraper mechanism  198  can include a plastic scraper member  204  that is urged into engagement with the disk face  200  by way of biasing member  206 . A housing  207  for the biasing member  206  has a side opening  207   a  through which a disk engaging portion  204   a  of the scraper member  204  extends. The biasing member can be in the form of a wave spring  206  that is effective to keep the plastic member  204  in scraping engagement with the disk face  200  even as the harder disk face  200 , e.g. of tungsten carbide material, wears the engaging surface of the plastic scraper member  204  down. In this manner, the scraper mechanism  198  will scrape the disk face  200  clean over a large number of cycles of the rotary anvil  26  before the scraper member  204  needs to be replaced. 
     FIG. 21 is a schematic of a room layout in which the rotary trimmer apparatus  10  can be utilized. As shown, upstream from the trimmer apparatus  10 , a high speed printing press  216  produces printed signatures which are subjected to other processing equipment such that the rotary trimmer apparatus  10  receives a shingled stream of signatures  16  that have not been diverted by an overhead conveyor  208  to a log stacker  209 . The trimmer apparatus  10  trims the signatures  16  with the trimmed signatures then transported to a compensating stacker  210  for either automated or manual pickup. After strapping of the trimmed signatures, a log gripper  212  can take logs of these signatures to the stacker which then delivers them to a palletizer  214 . 
     As is apparent, the rotary trimmer apparatus  10  is part of an integrated processing line for the signatures  16  post press. Accordingly, high speed operation of each of the pieces of equipment in the processing line is needed to obtain the maximum amount of throughput and allow the printing press to be run at its maximum operating speed. With the cutting apparatus  12  herein, the rotary trimmer apparatus  10  will be able to maximize the number of high quality of trim cuts of the signatures  16  it generates and thus achieve the maximum throughput of the rotary trimmer apparatus  10  for a maximum duration before knife maintenance is required. In addition, since the present apparatus  10  and method obviate the unknown variable associated with inexact operator setup of the gap spacing  37  between the knife  24  and anvil  26  as in prior setup techniques, more precise information will be developed as to the knife life based on known variables relating to the type of signatures  16  and operating speeds where the optimum gap spacing  37  for these variables is used. More exact knife life information is beneficial for many reasons such as allowing operators to know precisely when the knife  24  will be in need of maintenance so as not to start a press run with a knife  24  that is close to the end of its useful life. 
     While there have been illustrated and described particular embodiments of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention.