Auxiliary printing unit for a printing press, in particular a rotary printing press

An auxiliary printing unit assembly including an auxiliary press unit dimensioned to fit between the frame members of a press main frame. Stops on the main frame define a working position adjacent the press impression cylinder. A coupling assembly is journaled in the press main frame for interconnecting the press drive and the shaft of the press unit. The coupling assembly has an internally splined hollow drive shaft and an externally splined mandrel slidable in the drive shaft between inwardly extended and retracted positions. The mandrel has an expandible hub at its inner end dimensioned to mate with a recess in the press unit shaft when the mandrel is inwardly extended. The mandrel and press unit shaft have respective off-center registering elements which are also axially engaged when the mandrel is inwardly extended. Register indicia on the mandrel and the press unit shaft are so positioned that upon alignment thereof the registering elements are aligned with one another in readiness for axial engagement. A manually rotated transversely arranged operating shaft in the mandrel carries cams for sequentially (a) shifting the mandrel from its retracted position to its extended position and for (b) expanding the hub to insure a tight centered driving connection with the press unit shaft.

It is known to provide an auxiliary printing unit which is portable and 
which may be installed on a printing press in a position adjacent the 
impression cylinder for making a special printed impression upon the 
product. Auxiliary printing units most often take the form of "numbering 
boxes" for printing a number on the product. With the addition of an 
automatic stepping mechanism it is possible to number the printed 
impressions consecutively. 
U.S. Pat. No. 4,024,812 which issued May 24, 1977 describes an auxiliary 
numbering unit for a sheet-fed offset press in which the numbering unit 
and its inking arrangement are separately constructed and must be 
separately installed and removed, which requires additional set-up time. 
Moreover, the coupling assembly which drives the auxiliary mechanism 
occupies considerable space within the press main frame so that the full 
width between the frame members is not available for the auxiliary unit. 
Auxiliary printing units of unitary construction are also known as shown by 
German Auslegeschrift No. 22 23 686 which was published Nov. 30, 1972. 
Such unit really falls into a different category from the present since it 
is inherently much larger in size and requires a truck to install and 
remove; nor does the unit possess those features and advantages which 
distinguish the present construction. 
It is, accordingly, an object of the invention to provide an auxiliary 
printing unit which can be quickly mounted on, and removed from, an 
associated printing press as a complete, compact and lightweight unit. It 
is an object to provide, as part of the associated press, a novel coupling 
assembly which is journaled in the press main frame and which is readily 
brought into registered driving engagement with the press unit shaft. More 
specifically it is an object of the invention to provide an auxiliary 
press unit which may be manually slid into a reference position within the 
press seated adjacent the press impression cylinder without interference 
between any driving or registering elements. Following a simple 
registering step all that is required is to manually rotate an operating 
shaft through a partial turn to complete a tight, centered drive 
connection between the press drive and the shaft of the printing unit. 
It is a more specific object to provide a coupling assembly including a 
mandrel slidable in the press frame between a retracted position for 
insertion of the press unit into the press and an extended position in 
which the mandrel drivingly engages the press unit shaft. To provide 
prompt positive coupling between the two, the mandrel is provided with an 
expandible hub which engages a hollow at the end of the press unit shaft. 
Turning of the operating shaft results in automatic sequential motion of 
the mandrel to its extended position followed by the expansion of the hub 
into gripping engagement. 
It is another object of the invention to provide a registered drive 
connection for an auxiliary printing unit including a drive shaft mounted 
in the press frame with an interposed eccentric sleeve to achieve 
throw-off and positional adjustment of the printing unit with respect to 
the impression cylinder with which it cooperates. 
It is a further object of the invention to provide a coupling assembly of 
the above type which nevertheless occupies only a small amount of space, 
measured axially, within the press frame so that the printing unit may 
utilize substantially the full width between the side frames of the press. 
It is yet another object to provide a coupling assembly for an auxiliary 
press unit which requires only a partial turn of a single operating shaft 
for coupling-up, with reversal of the movement for subsequent uncoupling, 
following which the unit may be easily removed, as a unit, from the main 
press.

While the invention has been described in connection with a preferred 
embodiment, it will be understood that I do not intend to be limited to 
the particular embodiment shown but intend, on the contrary, to cover the 
various alternative and equivalent constructions included within the 
spirit and scope of the appended claims. 
Turning now to the drawings there is disclosed in FIG. 1 a sheet-fed rotary 
printing press 10 of the lithographic type having a pair of vertical main 
frame members 11 spaced parallel to one another, as is conventional, (only 
one being shown). Journaled in the frame members are a set of cylinders 
including a plate cylinder 12, with the usual sources of ink and water 13, 
a blanket cylinder 14 and an impression cylinder 15. The press, being 
sheet-fed, includes a sheet feeder 16 for feeding a series of sheets S 
between the impression and blanket cylinders where printing occurs. Each 
sheet is then transferred to a conveyor 17 for transport from the machine. 
All rotating members of the press are synchronously driven from a common 
press drive 18, the drive connections being indicated by respective dotted 
lines. 
The auxiliary press unit generally indicated at 20 has a frame which 
includes a pair of spaced vertical frame plates 21, only one of which is 
shown, which are supported on a seating surface adjacent the impression 
cylinder 15. The seating surface is in the form of a laterally spaced pair 
of rails 22 (only one of which is shown in FIG. 3), each of the rails 
being mounted upon a bracket 23 secured to the adjacent press frame 11 by 
a set of screws 24. A stop 25 (FIG. 2) mounted in the path of movement of 
the press unit along the rails 22 determines the operating position of the 
unit. 
Mounted between the frame members of the auxiliary press unit is an 
auxiliary printing cylinder 26 which, in the event the device is used as a 
numbering machine, has a concentrated raised printing area. The printing 
area is inked by an ink feed system generally indicated at 27. For 
supporting the printing cylinder 26 a press unit shaft 30 is provided 
which is journaled in bearings 31 mounted in the respective frame plates 
21. The shaft 30 is preferably of hollow construction so that the end of 
the shaft forms a hollow cylindrical recess 32. 
In accordance with the present invention a novel coupling assembly is 
provided for interconnecting the press drive 18 and the press unit shaft 
30. The coupling assembly comprises an internally splined hollow drive 
shaft coupled to the press drive and an externally splined mandrel 
slidable endwise in the drive shaft between inwardly extended and 
retracted positions, the mandrel having an expandible hub at its inner end 
dimensioned to mate with the recess in the press unit shaft to form a 
driving connection therewith when the mandrel is inwardly extended. 
Turning to FIG. 3, the coupling assembly indicated at 40 includes a hollow 
drive shaft 41 having a gear 42 at its outer end, the gear being coupled 
by a suitable drive train 43 to the press drive 18. The drive shaft is 
supported by a bearing 44 with respect to the main press frame member 11 
with interposed eccentric sleeves to which reference will later be made. 
The drive shaft is machined with a longitudinally extending set of 
internal splines 45. 
Slidably mounted in the drive shaft is a mandrel 50 having a matching set 
of internal splines 51. The mandrel is also of hollow construction having 
an axial bore 52 which is of stepped diameter extending from the outer end 
53 of the mandrel to the inner end 54. At its inner end the mandrel 
carries a hub 55 of cylindrical shape dimensioned to extend into the 
recess 32 at the end of the press unit shaft 30. The mandrel is slidable 
between the retracted position illustrated in FIG. 3 and the extended 
position illustrated in FIG. 5 in which the hub is in driving engagement 
with the shaft 30. 
In accordance with one of the features of the present invention the hub 55 
at the end of the mandrel is of the expandible type, that is, capable, 
upon actuation, of expanding radially into a tight centered position in 
the recess 32. As shown in FIG. 3a, the hub 55 includes a fixed clamping 
plate 56 which is supported upon stand-off pillars 57 parallel to, and a 
short distance from, the end 54 of the mandrel. Cooperating with the fixed 
clamping plate is a movable clamping plate 58 which is supported upon an 
integral plunger 60 slidably mounted in the bore 52. Interposed between 
the two clamping plates 56, 58 is a circular resilient clamping element 
59. The resilient clamping element is so dimensioned as to be freely 
accommodated in the recess 32 of shaft 30 as long as no stress is applied 
to it. However, when the movable clamping element 58 is thrust outwardly 
by the plunger 60 the clamping element 59 is compressed, expanding 
outwardly into tight centered engagement with the wall of the recess 32. 
Reference will shortly be made to the means for applying the clamping 
force to the plunger 60. It will suffice to say for the present that to 
facilitate application of such force the plunger is centrally relieved at 
61 to provide two reaction forces 62 which are spaced from one another. 
Attention will next be given to the means for moving the mandrel between 
the retracted position illustrated in FIG. 3 and the extended position 
illustrated in FIG. 5. In accordance with the invention a central plunger, 
or rod, is telescoped into the mandrel, the outer end of the plunger being 
anchored with respect to the press frame. A coil spring is interposed 
between the mandrel and the plunger for biasing the mandrel to a retracted 
position. The inner end of the plunger is engaged by a manually operated 
blocking element which acts against the biasing force of the spring 
thereby to determine the axial position of the mandrel. Thus as shown in 
FIG. 3 there is, telescoped into the mandrel, a plunger 70 having an outer 
end 71 which is fixed to an end cap 72 which is secured to the gear 42 by 
screws 73 or the like. Since the gear is journaled in bearing 44 which is 
fixed against endwise movement, the plunger 70 is axially fixed with 
respect to the main frame of the press. Interposed between the mandrel and 
the plunger is a coil spring 75, the outer end 76 of which is connected to 
the outer end of the mandrel while its inner end 77 is connected to the 
plunger. The spring, being stressed in compression, tends to urge the 
mandrel into its retracted state illustrated in FIG. 3. The axial position 
of the mandrel is determined by a variable blocking member interposed 
between the mandrel and the inner end 78 of the plunger, as will now be 
discussed. 
In accordance with one of the important aspects of the present invention a 
manual operator is provided for engaging the presented ends of the two 
plungers 70, 60 for shifting the mandrel and for expanding the hub in 
sequence, so that the hub is first inserted into the recess 32 in the 
shaft 30 followed by expansion of the hub into tight centered engagement 
with such recess as shown in FIG. 5. This is accomplished, according to 
the invention, by a manual operating shaft 80 which is transversely 
arranged for limited rotational movement in the right-hand end portion of 
the mandrel. The operating shaft carries a first cam 81 which is of the 
thin disc type and a two-part cam 82 of the same type but which is 
differently profiled. For journaling the operating shaft 80 it is fitted 
into a transverse bore 83. The cam 81 engages the inner end 78 of the 
plunger 70, while the two portions of the cam 82, which are identical to 
one another, engage the reaction faces 62 at the presented end of the 
plunger 60 associated with the expandible hub. The upper end of the 
operating shaft 80 is provided with a hex socket 84 for engagement by an 
allen wrench or similar turning tool 85. 
The manner in which the sequential movements of the mandrel and the hub are 
brought about, from the condition illustrated in FIG. 3 to that 
illustrated in FIG. 5, will now be apparent. Initially the operating shaft 
80 is manually turned to the condition corresponding to FIG. 3. In this 
position the presented end 78 of the plunger 70 occupies a "low" region 
81a (FIG. 3b) on cam 81 so that the mandrel is urged by the spring 75 into 
its retracted or left-hand position. Also as an initial state, the plunger 
60, associated with the hub, occupies a "low" region 82a on the cam 82 so 
that the plunger is released and the resilient clamping element 59 is 
unstressed and therefore easily fitted into the recess 32 of the shaft 30. 
When the operating shaft 80 is manually rotated by the turning tool 85 to 
an angle of approximately 45 degrees, which is the condition illustrated 
in FIG. 5b, the cam 81 is rotated to present its "high" region 81b to the 
plunger 70, with the reaction force exerted on the cam by the stationary 
plunger serving to crowd the mandrel to the right to its extended position 
in which the hub is inserted into the recess. The hub, at this point, 
remains unstressed. 
Upon further rotation of the operating shaft 80 in the clockwise direction, 
the "high" region 81b of the cam 81 remains in contact with the plunger 70 
so that the mandrel does not move axially any further. However, the final 
45 degrees of motion is sufficient to bring the "high" region 82b of the 
cam 82 against the end faces 62 of the hub plunger 60, causing the 
clamping element 59 to be compressed so that it expands outwardly into 
engagement with the wall of the recess 32 of shaft 30, providing tight 
nearly rigid engagement. When the operating shaft is subsequently rotated 
in the opposite direction, to restore the condition of FIG. 3b, the 
sequence is reversed, that is, the hub is contracted before it is 
withdrawn. 
In carrying out the invention means are provided for limiting the range of 
operating movement of the operating shaft 80 thereby to define the two 
extreme positions of the cam which are illustrated in FIGS. 3b and 5c and 
for automatically locking the operating shaft at the ends of its range. 
The range is defined by a stop 91 recessed in the wall 83 of the 
transverse bore in the operating shaft and by providing an arcuate groove 
92 in the shaft. While a 90 degree throw has been illustrated, it will be 
understood that the invention is not limited thereto. For locking the 
operating shaft in its extreme positions of throw, a locking pin 93 is 
axially arranged within the operating shaft with its head end 94 in the 
tool socket 84 and biased endwise by a spring 95. At its lower end the 
locking pin carries a smaller transversely mounted bayonet pin 96 which 
serves as a detent, engaging angularly spaced notches 97 at the end of the 
shaft. The bayonet pin is prevented from rotating by engagement of its 
ends in axially extending grooves 98 formed in the wall of the bore 83. 
It will be apparent, then, that when the turning tool 85 is inserted into 
the socket 84 at the head end of the operating shaft, the head 94 of the 
pin 93 is pressed downwardly against the force of the spring 95, unseating 
the bayonet pin 96 from the engaged notch 97, permitting the turning tool 
to turn the operating shaft to its alternate condition where it is 
automatically locked by simply withdrawing the tool. This insures that the 
position of the mandrel and condition of the hub thereon will not depart 
from the set conditions as a result of vibration or the like. 
In accordance with one of the aspects of the present invention the mandrel 
50 and press unit shaft 30 are fitted with registering elements which are 
axially engaged when the mandrel is inwardly extended, thereby to 
establish a desired phase relationship between them, and register indicia, 
including indicia on the mandrel and on the press unit shaft, are so 
positioned that, upon relative rotation to a position of alignment, the 
registering elements are aligned with one another in readiness for axial 
engagement. The registering elements are preferably in the form of an 
axially projecting pin 101 arranged off-center on the mandrel adjacent the 
projecting hub 55 and which fits snugly into a recess 102 in the form of a 
hardened pocket in a ring or flange 103 which is rigidly secured to the 
end of the shaft 30. It will be apparent, then, that the pin 101 is 
entered into its recess at the same time that the hub is entered into the 
end of the hollow shaft thereby to insure that the shaft is properly 
phased. 
For the purpose of insuring that the pin 101 and its recess 102 are aligned 
before they are engaged, registering indicia are provided between the 
mandrel and the main frame and between the frame and shaft of the press 
unit. As shown in FIG. 4 such indicia include a pointer 111 on the main 
frame cooperating with a registering mark 112 on the mandrel as well as a 
pointer 113 on the frame of the press unit cooperating with an index mark 
114 on the ring 103 of the shaft 30. In performing the register step the 
mandrel is disengaged as shown in FIG. 3 and the ring 103 is manually 
rotated to bring the indicia 113, 114 into alignment. The press drive is 
then jogged to bring the indicia 111, 112 into alignment. When this has 
been accomplished the pin 101 is precisely opposite the recess 102, and 
thus ready to move into it, when the mandrel is extended. 
For the purpose of shifting the press unit shaft broadwise for adjustment 
of the press unit cylinder 26 an eccentric sleeve 121 is effectively 
interposed between the main frame member 11 and the bearing 44 which 
supports the drive shaft which, in turn, supports the mandrel. Such 
eccentric sleeve is positioned by a worm and worm wheel assembly indicated 
at 122. To achieve throw-off, a second eccentric sleeve 123 surrounds the 
sleeve 121 and is connected by an arm 124 to a link 125 operated by the 
regular press throw-off mechanism 126. 
While there is shown, in FIG. 3, only that coupling assembly, with its 
supporting eccentric sleeves, which exists at one end of the shaft 30, it 
will be understood that the assembly is duplicated, in mirror image, at 
the other end of the shaft. Specifically there is at the other end of the 
shaft 30 a duplicate eccentric sleeve 123 having a linkage 125 connecting 
it to the press throw-off 126, so that when the press throw-off is 
operated both ends of the shaft 30 are moved, that is, thrown off, to 
equal degree. It will be understood, however, that the coupling assembly 
provided at the opposite end of the shaft 30 may be slightly simplified if 
desired, for example by omission of the gear wheel 42 on the drive shaft 
41 if driving is desired from one side of the press only. A stop 25 may be 
provided for each sub-frame 21. 
Since the amount of "throw" introduced by the eccentrics 121, 123 is quite 
small, throw-off can be accommodated by providing a resilient annular 
mount 127 for the bearings 31 at the respective ends of the shaft 30, with 
cheek members 128 fixed to the frame 21 to permit radial lost motion while 
precluding play in the axial direction. Where such members are present for 
radial guidance, the annular element 127 may simply be omitted and the 
coupling assemblies 40 may be relied upon for support and radial 
positioning of the press unit shaft. 
The auxiliary press unit may, if desired, be employed as a sequential 
numbering machine. In this usage a control shaft 130 is provided, mounted 
at its ends in the subframe 21, having means for oscillating the same back 
and forth for automatic incremental advance of the cipher wheels. Input is 
provided by a cam follower arm 131 which engages a cam disc 132 on the 
shaft 30. The rocking movements of the shaft 130 are transmitted to the 
cipher wheels diagrammatically indicated at 133. Rocking movement may be 
artificially imparted to the control shaft 130 by means of a manual arm 
134, if desired. 
It will be apparent that the above-described auxiliary printing unit amply 
meets the objects set forth above. The unit is compact and completely 
unitary. By grasping the handles at the upper end of the sub-frames the 
device may be readily lifted by one person onto the rails 22 and slid into 
place until the stop 25 is engaged which defines the seated or working 
position. By utilizing the indicia 111-114 the register pin is aligned 
with the recess, following which the turning tool 85 is inserted to turn 
the control shaft of the mandrel, which results in sequential extending 
movement of the mandrel and expansion of the hub into tight centered 
driving engagement with the press unit shaft. Note that a single actuator 
(shaft 80) serves to both shift the mandrel and, sequentially, to clamp it 
up. For removing the unit the procedure is simply reversed. 
Since the coupling assembly is primarily accommodated in the main frame 
members of the press, the auxiliary press unit may, if desired, occupy 
substantially the entire space available between the frame members. The 
clearance space, indicated at 140, between the adjacent frames is only a 
little more than that required for the registering indicia or for 
insertion of a turning tool into the socket of the operating shaft of the 
mandrel. 
While it is desired to provide a multiple spline to permit sliding movement 
of the mandrel within the hollow drive shaft, it will be understood that 
the term "spline" as used herein is not limited thereto and includes any 
rotationally keyed axially slidable connection. The term "stop" as applied 
to stop 25 which determines the operating position of the press unit, 
shall be understood to mean any locating means for precise positioning of 
the unit. While the cams 81, 82, although closely coupled, are separated 
from one another, lying in different planes, the term "cams" as used 
herein will be understood to refer to cam surfaces, whether or not in 
different planes. It will also be understood that the resilient clamping 
element 59, while described as "circular," may consist of separated pads 
of resilient frictional material spaced in a circular locus.