Notch timing device and method for card slitting machine

A slitting machine including a first slitting stage for producing a plurality of interrupted cut slits in an advancing sheet having a leading edge and a trailing edge includes a drive pulley, a driven pulley, and a belt engaging the drive pulley and the driven pulley to provide a power path and a return path between the drive pulley and the driven pulley. The slitting machine also includes a mechanism translating rotation of the driven pulley to drive an upper slitting assembly and notched blades of a lower slitting assembly in synchronization with the advancing of the sheet by a sheet feeder. A moveable idle pulley engages a portion of the belt in the power path, and an adjustment mechanism controls the moveable idle pulley to adjust the length of the power path, thereby varying the locations of the notches of the lower blades relative to the sheet being advanced, and thereby allows adjustment of the width of the margins at the leading and trailing edges of the advancing sheet to compensate for slippage of the advancing sheet due to variations in its thickness, type of material, and/or surface finish.

BACKGROUND OF THE INVENTION 
The invention relates to an improvement to a commercially available sport 
card slitting machine known as the "Rollem Slip Stream" machine, and more 
particularly to a device and method for conveniently adjusting the 
relative locations or "timing" of a pair of notches in the lower blades of 
a first stage slitter assembly relative to leading and trailing edges of 
an advancing photo sheet. 
Sport cards, such as baseball trading cards and the like, are very popular, 
and several major companies, including the present assignee, compete 
vigorously in this large market. 
In the manufacture of sport cards, a large number of photographs of various 
individual athletes are printed on each of many large, single sheets of 
suitable paper (herein referred to as "photo sheets"). Each large photo 
sheet then is slit, first "horizontally" and then "vertically", to form a 
group or collection of individual sport cards which then are collated and 
packaged. 
To this end, the sport card industry has used a card slitting machine 
called the "Rollem Slip Stream machine". The standard Rollem Slip Stream 
machine includes a first stage slitting assembly that is manufactured by 
Rollem, and is shown in FIG. 1. Various aspects of the Rollem Slip Stream 
machine are disclosed in U.S. Pat. No. 4,405,121 by Hill, issued Sep. 20, 
1983 entitled "Cutting and Collating Sheets of Paper Cards, etc.", and 
incorporated herein by reference. 
FIG. 1 herein shows a top view diagram of the Rollem Slip Stream machine 1. 
A large (typically 28 inches by 40 inches) photo sheet 40 is advanced 
along a first section 6, as indicated by arrow 3. A first stage slitting 
assembly 2 includes a lower blade assembly 15, 19 and an upper blade 
assembly 10, 18, as shown in FIG. 3. The prior art Rollem first stage 
slitting assembly 2 makes "interrupted cut" slits such as 41 in photo 
sheet 40, as shown in FIGS. 2 and 2A. The "interrupted cut" slits 41 are 
necessary to provide a leading edge margin 42A and a trailing edge margin 
42B so that photo sheet 40 remains intact, allowing it to be advanced as a 
unit in direction and then at a right angle thereto in direction 5, to a 
second stage slitting assembly 14 and then, after the "horizontal" 
interrupted cut slits 41 are made, into a second section 7. In first stage 
slitting assembly 2, a number of individual "interrupted cut" slits 41 are 
made, each of which extends to within approximately 1/2 inch of the 
opposed leading and trailing edges of photo sheet 40, leaving leading and 
trailing edge margins 42A and 42B, respectively, that maintain 
"horizontally" slit photo sheet 40 intact so further advancing and 
"vertical" slitting of the entire photo sheet 40 is possible. The second 
stage slitting assembly 14 cuts a second set of "vertical" slits (not 
shown) that are perpendicular to the "horizontal" interrupted cut slits 
41. 
Referring to FIG. 3, the prior art Rollem Slip Stream first stage slitting 
assembly 2 includes a number of upper hub/blade assemblies 18 mounted on a 
single gear-driven upper shaft 10. Each hub/blade assembly 18 includes a 
thin, circular upper blade 12 secured by set screws (not shown) to a 
planar face of an upper hub 11. Set screws (not shown) secure the various 
upper hubs 11 to shaft 10, which is journaled in several stationary 
bearing assemblies (not shown). 
Numeral 19 designates lower hub/blade assemblies of the standard Rollem 
first stage slitting assembly 2. Each lower hub/blade assembly 19 includes 
a thin circular blade 17 mounted on a hub 16, which in turn is mounted on 
a common gear-driven lower shaft 15. The drive of lower shaft 15 is 
"synchronized" with the drive of upper shaft 10 so that the cutting edge 
velocity of upper blade 12 is precisely the same as that of lower blade 
17. As shown in FIGS. 3 and 4, the lower portion of each upper blade 12 
and the upper portion of each lower blade 17 make contact in a "blade 
overlap" area. The upper blades 12 are urged against the corresponding 
lower blades 17 in the blade overlap area, as indicated by arrow 25 in 
FIG. 3. A sheet feeder 35 advances the leading edge of photo sheet 40 in 
the direction of arrow 34 in FIG. 4 in synchronization with the arrival of 
leading notch 17-1 in each of the lower blades 17 at the blade overlap 
area to determine the location of the leading end of each interrupted cut 
slit 41. When the trailing notch 17-2 of each lower blade 17 later arrives 
at the blade overlap area, it determines the location of the trailing end 
of each interrupted cut slit 41. 
As shown in FIG. 3, a resilient 0-ring 30 is disposed in a mating groove in 
each of upper hubs 11. As photo sheet 40 is advanced between the upper 
hubs 11 and lower hubs 16, resilient O-ring 30 frictionally contacts the 
upper surface of photo sheet 40 and aids in advancing it between the upper 
and lower slitter blades 12 and 17. If the upper surface of photo sheet 40 
is slippery because of the type of finish thereon, some slippage will 
occur between O-rings 30 and the upper surface of photo sheet 40. 
To produce the above-mentioned "interrupted cut" slits 41, lower blades 17 
each have two spaced "timing notches" 17-1 and 17-2, as shown in FIG. 4. 
The length of arc 45 between point A of leading timing notch 17-1 and 
point B of trailing timing notch 17-2 is equal to the length of an 
"interrupted cut" slit 41 if there is no slippage of photo sheet 40 
relative to lower blade 17. The feeding of photo sheet 40 is synchronized 
to the times at which timing notches 17-1 and 17-2 meet upper blade 12 to 
produce the leading half inch margin 42A and the trailing half inch margin 
42B (FIG. 2) that keep photo sheet 40 intact after the horizontal 
"interrupted cut" slits 41 are made. 
In order that timing notches 17-1 and 17-2 become aligned with leading and 
trailing edge portions, respectively, of photo sheet 40 at exactly the 
right times, the rotation, i.e., "timing", of upper blades 12 and lower 
blades 17 must be precisely coordinated with the advancement of photo 
sheet 40. A major problem that has arisen in use of the standard Rollem 
Slip Stream machine is that the photo sheets 40 are frequently formed on 
photo paper sheets of various thicknesses, kinds of paper, and surface 
finishes. It has been found that such variation in thickness and kind of 
photo paper and the differences in "slipperiness" of the various finishes 
result in different amounts of slippage of photo sheet 40 with respect to 
the mechanism 35 which advances it in the direction of arrow 34. This 
disturbs the relative position or "timing" between notches 17-1 and 17-2 
and the leading and trailing edges of photo sheet 40. 
In order to accurately slit photo sheets of different thicknesses, kinds of 
material, and/or surface finishes, it has been necessary to shut down the 
Rollem Slip Stream machine 1, loosen a chain-driven drive clamp located on 
the upper drive shaft, manually advance or retard the lower notched blade 
in order to advance or retard the timing notches thereon, re-tighten the 
drive clamp, and test the results by starting up the Rollem Slip Stream 
machine and running a photo sheet through it. Typically, several attempts 
have been required to obtain the correct notch timing. This has been a 
very labor-intensive, time-consuming, and expensive procedure. 
Consequently, there is an unmet need for a practical, economical solution 
to the above problems associated with varying amounts of slippage of photo 
sheets of various thicknesses, various kinds of paper, and various surface 
finishes, and especially to avoid the need to shut down operation of the 
Rollem Slip Stream machine and perform the time-consuming foregoing timing 
adjustment process. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the invention to provide a mechanism and 
technique for easily adjusting the timing of the notches on the lower 
slitting blades of a Rollem Slip Stream machine and the leading relative 
to trailing edges of an advancing photo sheet. 
It is another object of the invention to provide an apparatus and technique 
to compensate for variations in slippage of an advancing photo sheet as it 
passes through the first slitter stage of a Rollem Slip Stream machine due 
to variations in properties of various photo sheets. 
Briefly described, and in accordance with one embodiment thereof, the 
invention provides an improvement in a slitting machine which includes a 
first slitting stage adapted to produce a plurality of "interrupted cut" 
slits in an advancing sheet having a leading edge and a trailing edge. The 
first slitting stage includes a lower shaft, a plurality of cylindrical 
lower hubs rigidly mounted on the lower shaft, and a plurality of notched 
lower blades rigidly attached to the lower hubs, respectively. The first 
slitting stage also includes an upper shaft, a plurality of cylindrical 
upper hubs mounted on the upper shaft, and a plurality of upper blades 
attached to the upper hubs, respectively, wherein an edge portion of each 
rotating upper blade overlaps and engages an edge portion of a 
corresponding rotating lower blade to make the interrupted cut slits. A 
sheet feeder advances the sheet between the rotating lower blades and the 
upper blades. The improvement includes the combination of a drive pulley, 
a driven pulley, a fixed-length belt engaging the drive pulley and the 
driven pulley and defining a "power path" between the drive pulley and the 
driven pulley and a "return path" between the drive pulley and the driven 
pulley, a mechanism translating rotation of the driven pulley to drive the 
upper shaft and lower shaft in synchronization with the advancing of the 
sheet by the sheet feeder, a moveable idle pulley engaging a portion of 
the belt in the power path, an adjustment mechanism for moving the 
moveable idle pulley to adjust the length of the power path, and a 
tensioning mechanism engaging a portion of the belt in the return path to 
maintain tension of the portion of the belt in the return path as the 
length of the return path varies in response to the adjustment of the 
length of the power path. The location of the notches of the lower blade 
relative to the sheet being advanced by the sheet feeder therefore can be 
easily adjusted to adjust the margins between ends of the interrupted cut 
slits and the leading and trailing edges of the advancing sheet so as to 
compensate for varying amounts of slippage of various kinds of photo 
sheets as they are advanced through the first slitting stage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The present invention provides a way of solving the above described 
problems of the prior art by adjusting the effective length of a notched 
timing belt associated with the drive system that rotates the upper shaft 
10 and the lower shaft 15 shown in FIGS. 3 and 4. Before describing the 
present invention, however, it will be helpful to understand the slitter 
blade drive assembly of the prior art Rollem Slip Stream machine. This 
drive assembly is shown in FIG. 5. 
Referring to FIG. 5, the closest prior art arrangement for driving upper 
shaft 10 and lower shaft 15 includes a main drive timing pulley 50, which 
has precisely spaced notches that mesh with a correspondingly notched, 
fixed-length timing belt 52. Timing belt 52 drives a notched "driven 
pulley" or timing pulley 51, which is mounted on a common shaft with a 
gear 53. Gear 53 drives gear 54, which in turn drives gear 55. Gear 55 
drives gear 56, which is mounted on one end of the same upper shaft 10 
that carries the upper hubs 11 and blades 12. Gear 56 drives gear 57, 
which drives the same lower shaft 15 on which lower hubs 16 and blades 17 
are mounted. (It should be appreciated that suitable sprockets and chains 
could be used instead of timing pulleys and a notched timing belt.) 
It can be seen that the prior art arrangement of FIG. 5 provides a fixed 
relationship between the rotation of main drive pulley 50 and the rotation 
of upper blades 12 and lower blades 17. This arrangement does not allow 
convenient adjustment of the location or "timing" of notches 17-1 and 17-2 
in rotating lower blades 17 with respect to the locations or "timing" of 
the leading and trailing edges of the advancing photo sheet 40. Slippage 
of advancing sheet 40 therefore can result in elimination of either the 
leading edge margin 42A or the trailing edge margin 42B of advancing photo 
sheet 40. This would make it impossible for advancing photo sheet 40 to 
remain sufficiently intact as it exits from the first slitter station 2 as 
indicated by arrow 4 in FIG. 1 and moves through the second stage slitter 
14, to ensure accuracy of the transverse cuts made by second stage slitter 
14 (FIG. 1). 
Referring now to the embodiment of the invention shown in FIG. 6, a support 
frame 60 of the Rollem slitting machine 1 supports the upper and lower 
slitter assemblies 18 and 19 of FIGS. 3 and 4, the shafts 10 and 15, and 
also the sheet feeder advancing mechanism (not shown). All of the 
components shown in the prior art drive arrangement of FIG. 5 except 
timing belt 52 are also present in the drive arrangement of FIG. 6. 
In FIG. 6, the new combination of elements includes a belt tensioner 69, 
two idle pulleys 71 and 72, a vertically moveable idle pulley 70 the 
position of which is vertically adjustable in either of the directions of 
arrow 67, by simply turning a "notch timing adjustment" handle 61, and a 
longer timing belt 52A arranged as illustrated. 
More specifically, timing belt 52A loops around "drive" timing pulley 50, 
"driven" timing pulley 51, the upper surface of idle pulley 72, the lower 
surface of vertically moveable idle pulley 70, and the upper surface of 
idle pulley 71. The portion 52A of timing belt 52 extending between point 
E at which timing belt 52 departs from driven pulley 51, around idle 
pulley 72, moveable idle pulley 70, and idle pulley 71 to point F is 
referred to herein as the "power path" because rotation of drive pulley 50 
in the indicated direction produces enough tension in portion 52A of 
timing belt 52 to rotate driven pulley 51 by applying power to it. The 
portion 52B of belt 50 extending from point G of drive pulley 50 to point 
H of driven pulley 51 is referred to herein as the "return path". 
Notch timing adjustment handle 61 is connected to a vertical threaded shaft 
62 which extends through a threaded stationary nut block 63 and extends 
down to a vertically moveable pulley mounting block 64. A suitable 
"captured nut" or comparable structure 66 at the lower end of shaft 62 
causes vertical movement of pulley mounting block 64 by the vertical 
movement of threaded shaft 62 as notch timing adjustment handle 61 is 
rotated. Moveable idle pulley 70 is rotatably mounted on pulley mounting 
block 64. 
Belt tensioner 69 includes an air cylinder 76 anchored at one end 77 to 
frame 60 and having a moveable member pivotally connected to a mid-portion 
of an arm 74, and maintains a tensile force of approximately 15 pounds in 
timing belt 52 regardless of where moveable pulley 70 is vertically 
adjusted within its range. As notch timing adjustment handle 61 is 
rotated, thereby adjusting moveable idle pulley 70 up or down, arm 74 of 
air cylinder 76 pivots to allow tensioner idle pulley 73 to accommodate 
this change. 
In accordance with the present invention, vertical adjustment of idle 
pulley 70 in response to rotating of notch timing adjustment handle 61 
results in an effective lengthening or shortening of the power path 
portion 52A of belt 52 between main drive pulley 50 and driven pulley 51. 
If the total length of the portion of belt 52 in power path 52A is 
constant, then the amount of time required for an arbitrary point A of 
belt 52 moving in the direction of arrows 48 from point E at which belt 52 
departs from driven pulley 51 to point F at which belt 52 meets drive 
pulley 50 clearly is also constant. The rotation of lower slitter blade 
timing notches 17-1 and 17-2 is synchronized in a fixed predetermined 
fashion with advancement of photo sheet 40, because both photo sheet 40 
and notches 17-2 are moved in synchronization with main drive pulley 50. 
If the length of the portion of timing belt 52 in power path 52A changes as 
a result of turning notch timing adjustment handle 61, then the amount of 
time required for a point A of timing belt 52 to move from point E (where 
timing belt 52 departs from driven pulley 51) to point F (where timing 
belt 52 joins drive pulley 50) also changes. For example, if notch timing 
adjustment handle 61 is rotated to lower mounting block 64 and moveable 
idle pulley 70 so that timing belt 52 passes through the path indicated by 
dotted lines D', then the length of the power path 52A is increased by the 
difference between the length of the arc through the path B, D, C and the 
length of the arc through the path B, D', C. Consequently, the "phase" or 
timing of notches 17-1 and 17-2 relative to the leading and trailing edges 
of the advancing photo sheet 40 is adjusted proportionately. 
This effectively advances or retards the relative positions of notches 17-1 
and 17-2 of lower blades 17 relative to the leading and trailing edges, 
respectively, of advancing photo sheet 40. 
It has been found that for any particular type of photo paper and a 
particular surface finish thereof, the amount of slippage of photo sheet 
40 as it is advanced between the upper slitter blades 12 and lower slitter 
blades 17 is essentially constant. Therefore, that amount of slippage can 
be easily compensated for by simply turning notch timing adjustment handle 
61 until the leading and trailing edge margins of photo sheet 40 are 
equally balanced. The need to shut down the entire card slitting machine 
and make the above described drive clamp adjustments to balance such 
leading and trailing edge margins of photo sheet 40 has been avoided. 
While the invention has been described with reference to several particular 
embodiments thereof, those skilled in the art will be able to make the 
various modifications to the described embodiments of the invention 
without departing from the true spirit and scope of the invention. It is 
intended that all combinations of elements and steps which perform 
substantially the same function in substantially the same way to achieve 
the same result are within the scope of the invention. For example, pairs 
of closely spaced upper blades 12 and corresponding pairs of closely 
spaced lower blades 17 could be provided to make narrow "galley cuts" 
approximately one fourth of an inch apart to thereby cut out quarter inch 
wide strips between the various rows or columns of photos in photo sheet 
40 could be provided for example in the manner disclosed in my co-pending 
commonly assigned patent application "Floating Blade Slitting Device and 
Method", Ser. No. 08/194,045, filed Feb. 9, 1994, and incorporated herein 
by reference.