Net cartridge assembly for use with transfer and delivery cylinders in rotary printing presses

A cartridge assembly for providing a source of anti-smear fabric net material to be used to cover the support surface of a transfer or delivery cylinder in a printing press, the assembly comprising an axle assembly mounted to brackets attached to the cylinder and having a replaceable cartridge roll wound with a continuous supply of fabric net material supported thereon. Structure is provided for releasably locking the axle assembly against removal from the brackets, and for releasably locking the axle assembly against rotation relative to the brackets.

BACKGROUND OF THE INVENTION 
This invention relates to printing presses, and more particularly to a new 
and improved cartridge assembly for providing a source of fabric net 
material to be used to cover the support surface of a transfer or delivery 
cylinder in a high speed, sheet fed off-set rotary printing press. 
Disclosed in my U.S. Pat. No. 4,402,267 issued Sept. 6, 1983 and entitled 
"Method And Apparatus For Handling Printed Sheet Material", is a system 
for preventing the marking and marring of freshly printed sheets in a high 
speed, sheet fed off-set rotary printing press as the wet inked side of 
those sheets are supported by a transfer or delivery wheel or cylinder 
during transfer between processing stations within the press. That system, 
which has met with very substantial commercial success and worldwide 
acceptance in the printing industry, employs an ink repellent fabric 
material, referred to in the trade as a "net", loosely disposed over the 
support surface of the transfer or delivery cylinder, and which engages 
and clings to the wet ink side of the sheet as the sheet it being 
transferred over the cylinder. 
As described in my aforementioned U.S Pat. No. 4,402,267, it is important 
that the net be properly tensioned over the cylinder so that the net 
remains relatively loose during operation. In my later U.S. Pat. No. 
4,691,632 issued Sept. 8, 1987, there is disclosed a method and apparatus 
for attaching the anti-smear net to the cylinder so that the net may be 
readily and easily removed, installed and adjusted for proper tension. 
That later patent employs a pair of identical reel assemblies, one 
disposed adjacent the leading or gripper edge of the cylinder, and the 
other disposed adjacent the trailing or tail edge of the cylinder, and to 
which each end of the net is attached. By winding the net onto the reels, 
the proper tension of the net over the support surface of the cylinder can 
be maintained. 
While the reel assemblies disclosed in my U.S. Pat. No. 4,691,632 have 
simplified the mounting of nets to the cylinder and the maintenance of 
proper net tension during the useful life of the net, the net must still 
periodically be replaced when it becomes soiled and/or worn out after 
prolonged use and begins to mark the sheets, or if the net is in some way 
damaged or torn during operation. It has been found that frequently the 
net will become soiled in only a small area, typically adjacent the 
leading or gripper edge, and that when this occurs, the entire net will 
have to be removed from the press and replaced with an entirely new net. 
This requires that the press be stopped and the old net removed from the 
cylinder. Thereafter, the entire new net must be reinstalled over the 
cylinder by attaching the ends to the gripper and tail edges of the 
cylinder, a process which can result in significant loss of press 
production time while the net is removed and a new net reinstalled. 
Additionally, during operation of the press, the net material may be 
required to be adjusted to insure that the proper net tension over the 
cylinder is achieved for the particular printing job being run. This 
frequently requires that the press be stopped and the net tension adjusted 
by tightening the net slightly over the cylinder surface, since the net 
material may become stretched after prolonged use. 
Thus, there exists a need for a new and improved method and apparatus for 
permitting only the soiled or damaged portion of the net to be quickly and 
easily replaced and/or the net tension adjusted with a minimum of lost 
press production time, yet which is simple, relatively inexpensive and 
highly reliable. As will become more apparent from the following detailed 
description, the present invention solves this need in a unique and 
unobvious way. 
SUMMARY OF THE INVENTION 
The present invention provides a new and improved method and apparatus for 
permitting any amount of fabric net material to be replaced over the 
support surface of a transfer or delivery cylinder, and which is 
relatively simple in design, inexpensive to manufacture, yet is highly 
reliable in use and permits rapid net replacement and tension adjustment 
to minimize lost press production time. The present invention provides a 
cartridge assembly preferably mounted to the tail edge of a transfer or 
delivery cylinder and which supports a replaceable cartridge roll having a 
continuous supply of fabric net material wound thereon. The cartridge 
assembly and replaceable roll provide a source of supply of net material 
which can be quickly and easily advanced from the roll to replace any 
amount of old net material on the cylinder, from an amount sufficient to 
cover the entire support surface of the cylinder, to an amount sufficient 
to replace only a very small soiled or damaged portion of the net. With 
the cartridge assembly of the present invention, replacement of soiled or 
damaged net material and uniform adjustments in the net tension can be 
done very quickly, thereby minimizing the amount of lost press production 
time necessary to effect net replacement and adjustment. Moreover, with 
the replaceable cartridge of the present invention, a new supply of net 
material can be quickly and easily installed in the press by installing a 
new cartridge roll on the axle assembly whenever the old cartridge has 
become spent. 
In accordance with the invention, the cartridge assembly includes a pair of 
mounting brackets attached to the inner surface of the cylinder adjacent 
each end, and which support an axle assembly on which the replaceable 
cartridge roll is mounted. The cartridge assembly preferably extends along 
the tail edge of the cylinder, and includes means for releasably mounting 
and locking the axle assembly to the brackets. Means are also provided to 
releasably lock the cartridge assembly against rotation in one direction 
relative to the brackets to prevent the net material from unwinding from 
the cartridge roll during press operation, yet which can be simply and 
quickly released to permit fabric net material to be unwound from the 
cartridge roll when ever desired. Moreover, the releasable lock means 
includes a ratchet mechanism which permits the cartridge roll to be 
rotated in a direction to wind the fabric net material onto the roll 
without having to unlock the cartridge assembly, thereby to permit 
tightening adjustment of the net tension over the cylinder whenever net 
tensioning becomes necessary. 
The many features and advantages of the present invention will become more 
apparent from the following detailed description, taken in conjunction 
with the accompanying drawings which illustrate, by way of example, the 
principles of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
As shown in the exemplary drawings, the present invention is embodied in a 
cartridge assembly, generally designated by the reference numeral 10, 
intended to be used to provide a source of supply of ink repellant fabric 
material 12, referred to in the trade as a "net", for covering the outer 
support surface of a transfer or delivery wheel or cylinder 14 in a high 
speed, sheet fed off-set rotary printing press (not shown). In this 
instance, the transfer or delivery cylinder 14 is of the general type 
illustrated and described in my aforementioned U.S. Pat. No. 4,402,267, 
and is intended to be mounted in a printing press to support the wet ink 
side of a printed sheet as the sheet is transferred from one processing 
station within the press to another or to the delivery end of the press, 
as is well understood by those skilled in the printing press art. 
Herein, the cylinder 14 is formed as a cylindrical shell having axially 
spaced ends 16 and an inner surface 18 and an outer support surface 20 
which are discontinuous so as to form an axially extending opening 
defining a cylinder leading or gripper edge 22 and a cylinder trailing or 
tail edge 24, the opening being provided for cooperating with a gripper 
bar assembly (not shown) within the press which functions to withdraw and 
carry the printed sheet as it moves around the cylinder. Projecting 
radially inwardly from the inner surface 18 of the cylinder 14 are axially 
spaced mounting webs 26 terminating in U-shaped shaft brackets 28 for 
attaching the cylinder to a drive shaft (also not shown) within the press, 
the specific mounting and operation to the cylinder within the press being 
well known and understood by those skilled in the printing press art. 
As described in my aforementioned U.S. Pat. No. 4,402,267, the outer 
support surface 20 of the cylinder 14 is provided with a coating or 
covering of low friction material 30 over which the fabric net 12 is 
loosely disposed, the low friction coating permitting the net to cling to 
the printed sheet yet allowing the net to move relative to the support 
surface 20 of the cylinder 14 during transfer of a printed sheet, thereby 
to eliminate marking and marring of the wet ink surface. The net 12, which 
may be of the type manufactured and sold by Printing Research, Inc., of 
Dallas, Texas, under its registered trademark "SUPER BLUE", preferably is 
formed from loosely woven cotton cloth treated with an ink repellant 
substance such as that manufactured by the 3M Manufacturing Company, 
Minneapolis, Minn. under its Part No. FC4101-C-12, and is formed to have 
an unstretched width substantially equal to the axial length of the 
cylinder 14 so as to extend completely across the support surface 20 
between the axial ends 16 of the cylinder. 
In accordance with a primary aspect of the present invention, the cartridge 
assembly 10 is mounted to the inner surface 20 of the cylinder 14 herein 
adjacent the tail edge 24, and supports a replaceable cartridge roll, 
herein generally designated by the reference numeral 32, about which is 
wound a continuous supply of fabric net material 12. The cartridge 
assembly 10 and replaceable cartridge roll 32 provide a source of supply 
of net material 12 which can be quickly and easily pulled from the roll 
over the support surface 20 of the cylinder 14 and attached to the gripper 
edge 22, herein by securing the end of the net to an attaching strip 34, 
preferably a strip of the type made under the trademark VELCRO, disposed 
along the inner surface 20 of the cylinder adjacent the gripper edge. 
Moreover, the cartridge assembly 10 and removable cartridge roll 32 are 
constructed to operate in a highly reliable and effective manner to permit 
any amount of net material to be withdrawn from the roll, from an amount 
sufficient to provide a totally new net over the cylinder, to a very small 
amount sufficient to only replace a small portion of the net covering the 
cylinder, and when the supply of net material 12 has been exhausted from 
the roll, a new supply of net material can be quickly and easily replaced 
in the cartridge assembly. 
Toward the foregoing ends, as best can be seen in FIG. 3, which 
illustrates, in exploded perspective, the cartridge assembly 10 and 
cartridge roll 32 without the supply of fabric net material wound 
therearound, the cartridge assembly 10 includes a pair of mounting 
brackets 36 and 38, one disposed adjacent each axial end 16 of the 
cylinder 14, and which function to support an axle assembly 40 extending 
axially along the tail edge 24 of the cylinder between the brackets, and 
about which the cartridge roll 32 is disposed. Herein, each bracket 36 and 
38 is formed as a generally rectangular block, preferably of metal, having 
a radially outer peripheral surface 42 formed with a curve corresponding 
to the curvature of the inner surface 18 of the cylinder 14, and is 
secured to the cylinder by counter-sunk screws 44 to project radially 
inwardly from the inner surface of the cylinder. Each bracket 36 and 38 is 
also provided with a blind cylindrical socket 46 dimensioned to receive 
one end of the axle assembly 40 for rotation therein, the sockets being 
formed to open toward each other along an axis parallel with the tail edge 
24 of the cylinder 14 so that when the axle assembly 40 is mounted to the 
brackets, the center line of the axle assembly will be parallel with the 
tail edge and spaced radially inwardly from the inner surface 18 of the 
cylinder 14. 
The axle assembly 40 is formed to be removably mounted to the brackets 36 
and 38 of the cylinder 14, and when the press is in use, will normally be 
locked against rotation in the clockwise direction as viewed from the left 
end in FIG. 1 relative to the brackets, to prevent the fabric net material 
12 from unwinding from the cartridge roll 32 when the press is in use. As 
shown herein, the axle assembly 40 includes an elongated tubular axle 48 
of circular cross-section having a length that is equal to or slightly 
less than the distance between the facing sides of the brackets 36 and 38, 
and has a cylindrical passageway 50 extending longitudinally therethrough. 
Projecting outwardly from one end of the passageway 50 of the axle 48, 
herein the right end 39 as viewed in FIG. 3, is a plunger 52, preferably 
formed of metal, and having a cylindrical stem portion 54 dimensioned to 
slideably fit within the passageway 50 and an enlarged hexagonal shaped 
head portion 56 having flat faced sides 57, and is adapted and dimensioned 
to be rotatively received in the socket 46 of the adjacent bracket 38. The 
opposite end of the axle 48, that is, the left end 37 as viewed in FIG. 3, 
is dimensioned to be rotatively received in the socket 46 of its adjacent 
bracket 36, and is adpated to be releasably locked within the socket of 
the bracket. Importantly, the socket 46 of the left side bracket 36 as 
viewed in FIG. 3 is formed to have a smaller diameter than that of the 
socket in the right side bracket 38 so that the axle assembly 40 can only 
be installed in the brackets in the manner shown in FIG. 3. 
In this instance, as best seen in FIGS. 3, 7 and 8, the axle 48 is provided 
with an annular recess 58 formed adjacent the left end 37 to lie inside 
the socket 46 of the bracket 36, and which cooperates with a spring biased 
lock pin 60 mounted to the bracket to lock the axle assembly 40 in 
position. The lock pin 60 herein comprises a plunger, preferably of metal, 
having a cylindrical shank portion 62 terminating in a relatively small 
diameter nipple portion 64, and is provided with an annular groove 66 
formed in the shank adjacent the junction with the nipple portion. The 
lock pin 60 is received for sliding movement between extended and 
retracted positions in a bore 68 formed in the bracket 36 and which is 
located to intercept the socket 46 such that when the lock pin is 
installed within the bore, the cylindrical shank portion 62 will be 
aligned with and lie in the annular recess 58 of the axle 48. 
A spring 70 is positioned in the bore 68 to bias the lock pin 60 toward the 
extended position with the shank portion 62 in the recess 58 and the 
nipple portion 64 projecting outwardly from the radially inner face of the 
bracket 36, a stop shoulder 61 being formed by a reduced diameter section 
of the bore to prevent the pin from being withdrawn from the bracket. With 
the lock pin 60 in the extended position as shown in FIG. 7, the shank 
portion 62 will lie in the recess 58 to prevent the left end 37 of the 
axle 48 from being withdrawn from the socket 46, and the axle can be 
released from the socket only by depressing the nipple 64 to retract the 
lock pin against the bias of the spring 70 and bring the groove 66 in the 
shank into alignment with the recess 58 in the axle, the depth of the 
groove being formed to permit the left end of the axle to be withdrawn 
past the locking pin when aligned therewith. 
At the right end 39 of the axle assembly 40, as best can be seen in FIGS. 
5, 6 and 9, the plunger 52 is mounted with the stem portion 54 disposed in 
the passageway 50 and biased outwardly therefrom by a spring 72 which is 
compressed between the end of the stem opposite the head 56 and a 
cylindrical plug 76 seated against an internal shoulder 74 formed by a 
reduced diameter portion of the passageway inwardly of the end of the axle 
48. The plug 76 functions to prevent the inner end of the spring 72 from 
distorting and moving further into the passageway 50. With this 
arrangement, the plunger 52 is normally biased by the spring 72 toward an 
extended position so that the axle assembly 40 can be installed in and 
removed from the brackets 36 and 38 simply and quickly by compressing the 
plunger into the passageway 50 against the bias of the spring 7 to free 
the right end 39 of the axle from engagement with its socket 38, and then 
depressing the nipple 64 of the lock pin 60 to release the left end 37 for 
withdrawal of the axle from the bracket 36. Preferably, the head 56 of the 
plunger 52 is larger than the left end 37 of the axle 48 and the socket 46 
for receiving the head of the plunger will have a larger diameter than 
that of the socket within which the left end is mounted so that the axle 
assembly 40 can only be installed with the plunger in the proper bracket 
and cannot be accidently reversed. 
The replaceable cartridge roll 32, which preferably is formed from a 
relatively inexpensive material such as PVC plastic, is tubular in shape 
and is mounted to the axle 48 by sliding the roll over one of the ends, 
herein the left end 37, the length of the roll being slightly less than 
the length of the space between the inside faces of the mounting blocks 36 
and 38 to permit the axle assembly 40 to be removed from the brackets. 
Prior to assembly onto the axle 48, the roll 32 is wound with an amount of 
fabric net material 12 sufficient to permit recovering of the support 
surface 20 of the cylinder 14 numerous times, the only restriction on the 
amount of material used being space limitations dictated by the particular 
type of press and the radial space available inside the cylinder shell. 
Typically, sufficient net material 12 can be provided to approximately 
equal six times the surface area of the support surface 20 of a cylinder 
14. 
As best seen in FIGS. 3, 9 and 10, to couple the cartridge roll 32 to the 
axle 48, herein a coupling pin 41 is secured transversely through the axle 
and extending into diametrically opposed, axially directed blind slots 33 
formed in the end of the roll, the pin having a length equal to the 
diameter of the outer surface of the roll such that with the roll 
installed on the axle, the end portions of the pin will be received in the 
slots and couple the axle to the roll. The pin 41 projects through an 
elongated slot 55 formed diametrically through the stem portion 54 of the 
plunger 52, the slot having an axial length sufficient to permit the 
plunger to be moved between the extended and retracted positions for 
removal and reassembly of the axle assembly 40 in the brackets 36 and 38. 
With this arrangement, once the supply of net material 12 has been 
exhausted from the roll 32, a new cartridge roll with fabric net material 
wound thereon can be quickly and easily replaced on the axle assembly, 
thereby minimizing the lost press production time required for net 
changes. That is, all that need be done to replace the cartridge roll 32 
is to remove the axle assembly 40 from the brackets 36 and 38 and slide 
the spent cartridge roll off the axle 48, and then slide a new cartridge 
roll with a new supply of net material 12 wound therearound onto the axle 
and replace the axle assembly into the brackets. Of course, should it be 
desirable to rewind new net material 12 onto the old roll 32, this can 
also be done by attaching the free end of a continuous supply of net 
material to the surface of the spent roll, typically by using an adhesive 
strip or other fastening means such as a VELCRO strip, and then winding 
the desired amount of fabric onto the roll. 
When in use, the axle assembly 40 and the cartridge roll 32 are locked in 
position and can not be rotated relative to the brackets 36 and 38 in a 
direction to unwind the fabric net material 12. When it is desired to 
withdraw fabric net material 12 from the roll 32 for replacing soiled or 
damaged net material over the support surface 20 of the cylinder 14, the 
axle assembly 40 can be quickly and easily released from its locked 
condition to permit unrestricted and free rotation of the axle 48 relative 
to the brackets 36 and 38. Toward this end, the hexagonal head 56 of the 
plunger 52 is dimensioned to be rotatively received in the socket 4 of the 
adjacent bracket 38, and a spring biased lock pin 78, which is generally 
similar in construction to that of the lock pin 60 for locking the left 
end 37 of the axle 48 to the bracket 36, is provided for releasably 
locking the axle against rotation in one direction with respect to the 
bracket. 
As best can be seen in FIGS. 5 and 6, the lock pin 78 comprises a plunger 
formed by a cylindrical shank portion 80 terminating in a nipple portion 
82 of reduced diameter, and having an annular groove 84 disposed about the 
shank adjacent the nipple. The lock pin 78 is disposed for movement 
between extended and retracted positions in a bore 86 formed in the 
bracket 38 to intercept the socket 46 such that when the pin is in the 
extended position, the cylindrical shank portion 80 will abut one of the 
flat faces 57 of the hexagonal head 56 of the plunger 52. A spring 88 is 
compressed within the bore 86 against the end of the shank 80 and biases 
the lock pin 78 toward the extended position with the nipple 8 projecting 
outwardly from the inner face of the bracket 38, a stop shoulder 79 being 
formed by a reduced diameter portion of the bore to prevent the pin from 
being withdrawn from the bracket. With the lock pin 78 in the extended 
position shown in FIG. 5, the head portion 56 of the plunger 52 is 
prevented from rotating in the clockwise direction within the socket 46 
which, of course, also will prevent the plunger 52, axle 48, and cartridge 
roll 32 from being rotated in that direction. By locking the axle assembly 
40 and cartridge roll from rotating in the clockwise direction relative to 
the brackets 36 and 38 as viewed in FIG. 5, the axle assembly 40 is 
prevented from turning in a direction to permit unwinding of the net 
material 12, thereby maintaining net tension over the support surface 20 
of the cylinder 14 during press operation. 
To permit the axle assembly 40 and cartridge roll 32 to rotate for removal 
of net material 12, all that need be done is to depress the nipple 82 as 
shown in FIG. 6 to move the lock pin 78 inwardly against the bias of the 
spring 88 and bring the groove 84 into alignment with the head 56 so that 
the head will be free to rotate within the socket 46, the groove being 
herein formed as a radiused curve having a diameter substantially equal to 
the maximum effective diameter of the hexagonal head 56 so that the groove 
has a depth sufficient to permit the hexagonal head to rotate freely when 
alined therewith. Once the lock pin 78 has been depressed to permit the 
cartridge roll 32 to be rotated, any amount of fabric net material 12 can 
be removed quickly and easily from the roll. After the net material 12 has 
been withdrawn from the cartridge roll 32, by releasing the lock pin 78, 
the axle assembly 40 and cartridge roll will again be locked against 
rotation in the clockwise direction since the spring 88 will return the 
shank 80 to the extended position abutting the head 56. 
In accordance with another important aspect of the present invention, the 
hexagonal head 56 of the plunger 52 cooperates with the lock pin 78 to 
form a ratchet mechanism which permits the axle assembly 40 to be rotated 
in the counter clockwise direction as seen in FIG. 5 without having to 
depress the lock pin, thereby to permit the tension of the net material 12 
over the support surface 20 of the cylinder 14 to be tightened quickly and 
easily with a minimum of lost press production time. As can best be seen 
in FIG. 5, with the lock pin 78 in the extended position, the shank 
portion 80 is engaged with a portion of one of the flat faces 57 of the 
head 56. Should, however, a torque in the counter clockwise direction be 
applied to the axle assembly 40, the hexagonal head will rotate into the 
groove 84 and abut against the increasing radius portion of the groove to 
cause the lock pin to retract slightly against the bias of the spring 88. 
This retraction of the lock pin 78 functions as a ratchet mechanism which 
will permit fabric net material 12 to be wound onto the cartridge roll 32, 
thereby permitting the net tension to be uniformly tightened without 
having to depress the nipple portion 82 of the lock pin, but which will 
continue to prevent reverse rotation and unwinding of the net material so 
long as the lock pin remains in the extended position. 
By way of example, when it is desired that any amount of new fabric net 
material 12 is needed to replace soiled or worn net material, all that 
need be done is to release the edge of the soiled net from the fastener 
34, depress the lock pin 78, and then pull out the desired amount of new 
net from the cartridge roll 32. Thereafter, the old net material is cut 
off and the free edge of the new net material is secured to the gripper 
edge fastener 34. To properly tension the new net material 12 over the 
support surface 20 of the cylinder 14, the lock pin 78 is released to 
permit the lock pin to return to the extended position, and the the axle 
assembly 40 is manually turned in the counter clockwise direction to wind 
in the necessary amount of net material to achieve the proper net tension. 
Should it be necessary to let out net material 12 from the cartridge roll 
32 to achieve proper net tension, the nipple 82 can quickly and easily be 
depressed to retract the lock pin 78 and free the axle assembly 40 for 
rotation in the clockwise direction. 
From the foregoing, it should be apparent that the present invention 
provides a new and improved method and apparatus for permitting any amount 
of soiled or damaged fabric net material to be replaced over the support 
surface of a transfer or delivery cylinder of a press, and which permits 
easy and fast net replacement and/or net tension adjustment thereby to 
reduce lost press production time. Moreover, the present invention allows 
the press operator to have a constant supply of new net material for 
replacement when ever needed, and the removable cartridge allows rapid and 
easy replacement of the net supply when the old cartridge becomes spent. 
While the foregoing invention has been described in connection with the 
mounting of the cartridge assembly 10 to the trailing or tail edge 24 of 
the cylinder 14, there may be instances where it is desirable to mount the 
cartridge assembly to the leading or gripper edge 22. Should space and 
press configuration permit mounting to the gripper edge 22, all that need 
be done is to change the location of the mounting brackets 36 and 38 from 
the tail edge 24 to the gripper edge, and change the location of the 
fastening strip 34 from the gripper edge to the tail edge. Of course, the 
brackets 36 and 38 would also have to be reversed left to right to 
maintain proper orientation of the cartridge roll 32 with respect to the 
lock pin 78 to insure that the fabric net material 12 would not unwind 
during press operation. 
Those skilled in the art will appreciate that a variety of modifications 
and changes to the present invention may be made without departing from 
the spirit and scope of the invention as defined in the appended claims.