Printing apparatus and method

An auxiliary apparatus is provided to supply ink to a printing press upon failure of a main ink pump assembly in the printing press. The auxiliary apparatus includes a portable auxiliary ink pump assembly which is maintained separate from the printing press during normal operation of the main ink pump assembly. Upon failure of the main ink pump assembly to properly supply ink, the auxiliary ink pump assembly is moved to a location adjacent to the failed main ink pump assembly. The failed main ink pump assembly is disconnected from the ink rail of the printing press. The auxiliary ink pump assembly is connected in fluid communication with the ink rail. A motor connected with the auxiliary ink pump assembly then drives the auxiliary ink pump assembly to supply ink to the ink rail. The speed of operation of the motor and auxiliary ink pump assembly is varied as a function of variations in the operating speed of the printing press and the density with which ink is printed on sheet material moving through the press.

BACKGROUND OF THE INVENTION 
The present invention relates to a printing apparatus and method and, more 
specifically, to the use of an auxiliary ink pump to supply ink to a 
printing press in the event of failure of a main ink pump. 
During operation of a printing press, an ink pump may fail to supply ink to 
an ink rail of the printing press. When this occurs, the printing press 
may be shut down and the pump assembly repaired. Once the pump assembly 
has been repaired, the printing press resumes production. Of course, 
having a printing press out of production for the time required to repair 
an ink pump is detrimental to efficient commercial operation of a printing 
press. 
SUMMARY OF THE INVENTION 
The present invention provides a new and improved apparatus and method for 
supplying ink to a printing press upon failure of a main ink pump. The 
apparatus includes a portable auxiliary ink pump which is maintained 
separate from the printing press during normal operation of the main ink 
pump. Upon failure of the main ink pump to supply ink to the printing 
press, the auxiliary ink pump is moved from a remote location spaced from 
the printing press to an operating location adjacent to the failed main 
ink pump. A conduit is provided to connect auxiliary ink pump in fluid 
communication with the printing press. A motor connected with the 
auxiliary ink pump is then operated to drive the auxiliary ink pump to 
supply ink to the printing press through the conduit. 
Accordingly, it is an object of this invention to provide a new and 
improved apparatus and method for use in supplying ink to a printing press 
upon failure of a main ink pump and wherein a portable auxiliary ink pump 
is connected with the printing press to supply ink upon failure of the 
main ink pump.

DESCRIPTION OF A SPECIFIC PREFERRED EMBODIMENT OF THE INVENTION 
Printing Press 
An offset lithographic printing press 10 of a generally known construction 
is illustrated schematically in FIG. 1. The printing press 10 includes a 
pair of blanket rolls 12 and 14 which print on opposite sides of a sheet 
material web 16 during operation of the printing press. An ink image is 
transferred to the blanket rolls 12 and 14 by a pair of plate rolls 18 and 
20. 
To provide for the formation of an ink image on the plate rolls 18 and 20, 
water or other dampening solution is supplied to the plate rolls by 
dampener assemblies 24 and 26. Ink is applied to the surface of the plate 
rolls 18 and 20 by identical main inker assemblies 28 and 30. Thus, during 
operation of the printing press, ink is applied to ink transfer rolls 32 
and 34 by ink rails 36 and 38. The ink rails 36 and 38 are supplied with 
ink from main pump assemblies 40 and 42 disposed at pumping stations in 
the printing press (10). The main pump assemblies 40 and 42 are driven by 
main motors 44 and 46 disposed at the pumping stations in the printing 
press (10). It should be understood that each ink rail 36 or 38 is 
supplied with ink by a plurality, for example eight or ten, identical main 
pump assemblies 40 or 42 driven by identical main motors 44 or 46. 
Although it is preferred to use main inker assemblies 28 and 30 constructed 
in accordance with the present invention in an offset lithographic 
printing press, it should be understood that the main inker assemblies 28 
and 30 could be associated with a different type of printing press if 
desired. The press 10 may print on the web 16 or may be of the sheet feed 
type. In addition, a different type of inker assembly could be used. Thus, 
rather than using the ink rail 36 to apply ink to the roll 32, ink could 
be sprayed onto the roll or directly onto the plate roll if desired. Thus, 
it should be understood that the invention is not to be considered as 
being limited to use in any particular type of printing press. 
Inker Assembly 
The inker assembly 28 includes a variable speed main electric motor 44 
(FIG. 2) disposed at a pumping station in the printing press (10). The 
main motor 44 has an output shaft 50 connected with a main drive assembly 
52. The main drive assembly 52 is in turn connected with a cylindrical 
piston 54 of the main pump assembly 40. The main pump assembly (40) is 
disposed at a pumping station in the printing press (10). During operation 
of the main motor 44, the main drive assembly 52 reciprocates the piston 
54 to operate the main pump assembly 40. Although only a pair of main 
electric motors 44, drive assemblies 52 and pump assemblies 40 have been 
shown in FIG. 2, any desired number could be used. For example, four or 
five pairs of main electric motors 44, drive assemblies 52 and pump 
assemblies 40 could be used to supply ink to the ink rail 36. 
The main electric motor 44 is of the well known stepper type. Thus, during 
operation of the main motor 44, the output shaft 50 is moved through equal 
length increments or steps. These steps occur so fast as to appear to be a 
continuous rotational motion. 
Rotation of the motor output shaft 50 operates the main drive assembly 52 
to reciprocate the piston 54. Thus, the motor output shaft 50 is fixedly 
connected to a crank arm 58 (FIG. 2) which forms an input member for the 
drive assembly 52. The crank arm 58 is rotated about the central axis of 
the motor output shaft 50 during operation of the motor 44. 
The drive assembly 52 includes a cylindrical output member or drive pin 62 
which extends through a spherical ball 64 of a ball and socket type 
universal joint 66. The ball and socket universal joint 66 is mounted on 
the crank arm 58 and rotates with the crank arm. The ball and socket 
universal joint 66 includes a circular socket 68 which is fixedly 
connected with the crank arm 58. The ball 64 is rotatably held by the 
socket 68 and is free to rotate relative to the crank arm 58 during 
rotation of the crank arm. 
The drive pin 62 extends through a cylindrical opening in the ball 64. 
During rotation of the crank arm 58, the drive pin 62 slides axially in 
the opening in the ball 64. The opposite end of the drive pin 62 is 
fixedly secured to the outer end of the piston 54. During rotation of the 
crank arm 58 by the motor output shaft 50, the crank arm rotates from the 
position shown in solid lines in FIG. 2 to the position shown in dashed 
lines in FIG. 2. 
The general construction of the main drive assembly 52 is known and is 
generally similar to the construction of drive assemblies disclosed in 
U.S. Pat. Nos. 3,168,872 and 3,366,051. It is contemplated that other 
known types of drive assemblies could be utilized if desired. For example, 
a wobble or cam plate similar to the one disclosed in U.S. Pat. No. 
4,461,209 could be used if desired. 
The main pump assembly 40 includes a cylinder or housing 76 which is 
fixedly connected with a stationary base 78. The cylindrical piston 54 is 
slidably received in the cylinder 76 and cooperates with the cylinder to 
define a variable volume pump chamber 82. 
The main pump assembly 40 operates through one complete operating cycle for 
each revolution of the motor output shaft 50 and crank arm 58. Rotation of 
the motor output shaft 50 through one-half of a revolution rotates the 
crank arm 58 from the position shown in solid lines in FIG. 2 to the 
position shown in dashed lines. As the crank arm 58 rotates from the 
position shown in solid lines to the position shown in dashed lines, the 
piston 54 moves leftwardly (as viewed in FIG. 2) along a linear path 
through a discharge stroke. When the piston 54 is in the extended position 
shown in solid lines in FIG. 2, at the beginning of a discharge stroke, 
the cylindrical pump chamber 82 has a maximum volume. When the crank arm 
58 is rotated to the retracted position shown in dashed lines in FIG. 2, 
the piston 54 will have moved through a linear discharge stroke and the 
pump chamber 82 will have a minimum volume. 
Continued operation of the motor 44 rotates the crank arm 58 through 
one-half of a revolution from the position shown in dashed lines in FIG. 2 
to the position shown in solid lines in FIG. 2. As this occurs, the piston 
54 moves through a linear intake stroke and the size of the pump chamber 
increases. Thus, the volume of the pump chamber increases from a minimum 
volume to a maximum volume as the crank arm 58 rotates from the retracted 
position shown in dashed lines in FIG. 2 to the extended position shown in 
solid lines in FIG. 2. 
As the crank arm 58 reciprocates the piston 54 along a linear path, the 
crank arm also rotates the cylindrical piston about its central axis. As 
the piston 54 is rotated, a valve surface or flat 86 on the piston rotates 
relative to an intake port 88 and a discharge port 90 to control fluid 
flow into and out of the pump chamber 82. The valve surface 86 intersects 
and extends parallel to a longitudinal central axis of the cylindrical 
piston 54. 
During the intake portion of the pump operating cycle, the pump chamber 82 
increases in volume. Thus, during the intake portion of the pump operating 
cycle, the piston 54 moves from the retracted position shown in dashed 
lines in FIG. 2 to the extended position shown in solid lines in FIG. 2. 
As this occurs, an arcuate outer side surface of the cylindrical piston 54 
blocks the outlet port 90. At this time, the flat or valving surface 86 
cooperates with the inlet port 88 to enable ink to flow from an inlet 
passage 94 through the inlet port 88 into the cylindrical pump chamber 82. 
During the discharge portion of the pump operating cycle, the piston 54 
moves from the extended position shown in solid lines in FIG. 3 to the 
retracted position shown in dashed lines in FIG. 3 with a resulting 
decrease in the volume of the pump chamber 82. As this occurs, the arcuate 
side surface of the piston 54 blocks the inlet port 88. The flat valve 
surface 86 on the piston cooperates with the outlet port 90 to allow ink 
to flow from the contracting pump chamber 82 through the outlet port. 
The pump assembly 40 has a construction and mode of operation similar to 
the pump assemblies disclosed in U.S. Pat. Nos. 3,168,872 and 3,366,051. 
However, it should be understood that other known types of pump assemblies 
could be utilized in place of the specific pump assembly 40 illustrated in 
FIG. 3. If desired, a gear unit could be connected between the motor 44 
and drive assembly 52 so that each revolution of the motor shaft 50 would 
not result in operation of the pump assembly 40 through a complete 
operating cycle. It should be understood that although only a pair of 
motors 44, drive assemblies 52 and pump assemblies 40 have been shown in 
FIGS. 2 and 3, additional motors, drive assemblies and pump assemblies are 
provided. 
The construction of the drive assembly 52 is such that equal increments of 
rotation of the motor output shaft 50 and crank arm 58 do not result in 
equal increments of linear movement of the piston 54. As a result of the 
conversion of rotational motion of the motor output shaft 50 to linear 
motion of the piston 54, the displacement or movement of the piston 54 
varies as a generally sinusoidal function of rotation of the crank arm 58. 
Thus, if the motor output shaft 50 and crank arm 58 are rotated at a 
constant speed, the speed of movement of the piston 54 will vary during 
the intake and discharge strokes. This results in a relatively large 
displacement of the piston 54 relative to the cylinder 76 occurring for 
each increment of rotation of the motor output shaft 50 and crank arm 58 
when the piston 54 is near the central portion of either an intake or 
discharge stroke. When the piston 54 is near the beginning or end of an 
intake or discharge stroke, there is a relatively small displacement of 
the piston relative to the cylinder 76 for each increment of rotation of 
the motor output shaft 50 and crank arm 58. 
The rate of flow of ink from the pump chamber 84 is a direct function of 
movement of the piston 54. In order to obtain a constant ink flow rate 
from the pump assembly 40, it is necessary to maintain the speed of 
movement of the piston 54 constant during a discharge stroke of the 
piston. Thus, to enable the pump assembly 40 to discharge ink through the 
outlet 90 at a constant flow rate, the piston 54 must move at a constant 
speed from the extended position shown in solid lines in FIG. 2 to the 
retracted position shown in dashed lines in FIG. 2. 
The drive assembly 52 cooperates with the piston 54 in such a manner that 
if the motor output shaft 50 is rotated at a constant speed, the speed of 
movement of the piston 54 varies. Thus, if the speed of operation of the 
motor 44 is maintained constant, the flow rate of ink from the pump 
assembly 40 will vary. During constant speed rotation of the motor output 
shaft 50, there will be a relatively small or low flow rate of ink from 
the pump assembly 40 when the piston 54 is adjacent to either its 
beginning or end of stroke positions. There will be a relatively large 
flow rate of ink from the pump assembly 40 when the piston 54 is adjacent 
to the central portion of its stroke. 
This uneven flow of ink from the pump assembly 40 during rotation of the 
motor output shaft 50 at a constant speed results from the conversion of 
the circular rotational motion of the crank arm 58 to linear motion of the 
piston 54. Of course, a nonuniform flow rate of ink from the pump assembly 
40 during a discharge stroke of the piston 54 is detrimental to the 
quality of print obtained with the printing press. 
During an intake stroke of the pump assembly 40, the flow of ink from the 
pump assembly is stopped. However, during the intake stroke of the pump 
assembly, the printing press is still printing on the web 16 (FIG. 1). 
Therefore, the demand for ink continues during the intake stroke of the 
pump assembly 40. If the motor output shaft 50 is rotated at a constant 
speed, the duration of an intake stroke of the pump assembly 40 is equal 
to the duration of the discharge stroke of the pump assembly. Therefore, 
during one-half of the time the pump assembly 40 is being operated, there 
would be no ink flow from the pump assembly. 
Although there is a constant demand for ink by the printing press 10 during 
operation of the printing press, the demand for ink varies as a function 
of operating speed of the printing press. Thus, when the printing press 10 
is operating at a relatively slow speed, the amount of ink applied to the 
web 16 for each increment of time is less than the amount of ink applied 
to the web 16 for each increment of time when the printing press is 
operating at a high speed. Therefore, the greater the operating speed of 
the printing press, the greater is the need for ink to be discharged from 
the pump assembly 40. 
Motor Control System 
Although one specific main pump assembly 40 and main drive assembly 52 have 
been illustrated in association with a motor 44 in FIG. 2, other known 
pump assemblies and drive assemblies could be used if desired. In fact, it 
is contemplated that rather than being driven by individual motors 44, a 
plurality of ink pumps of a known construction could be driven by a single 
motor or by the printing press drive; in a known manner. Thus, a single 
motor could be used to drive a plurality of ink pumps as is disclosed in 
U.S. Pat. No. 3,608,486. If desired, the ink pumps could be driven by a 
printing press drive, as is disclosed in U.S. Pat. Nos. 3,366,051; 
2,866,411 and 2,695,561. 
During operation of the pump assembly 40, the speed of operation of the 
motor 44 is varied to minimize the duration of the intake portion of the 
pump operating cycle and to maximize the duration of the discharge portion 
of the pump operating cycle. Thus, in one specific embodiment, the piston 
54 was moved through an intake stroke, that is, from the position shown in 
dashed lines in FIG. 2 to the position shown in solid lines in FIG. 2, in 
about 0.125 seconds. Depending upon press operating speed and the demand 
for ink, the operating speed of the pump during the discharge stroke could 
be such as to have a discharge stroke of a duration which is between 5 and 
100 times the duration of the intake stroke. Thus, depending upon the 
demand for ink, the motor 44 is operated to move the piston 54 from the 
position shown in solid lines in FIG. 2 to the position shown in dashed 
lines in FIG. 2 in 0.625 to 12.50 seconds while the intake stroke is 
completed in only 0.125 seconds. 
By having the duration of the discharge stroke of the pump assembly 40 be 
between 5 and 100 times the duration of the intake stroke, a flow of ink 
is maintained from the pump assembly 40 during the large majority of each 
operating cycle of the pump assembly. Of course, the duration of the 
discharge portion of the pump operating cycle will vary as a function of 
the amount of ink required to print specific text or images on the web 16. 
The duration of the discharge portion of the pump operating cycle will 
also vary as a function of operating speed of the printing press 10. Thus, 
the slower the operating speed of the printing press, the longer is the 
discharge portion of the pump operating cycle. 
Since the duration of the intake portion of the pump operating cycle is so 
much shorter than the duration of the discharge portion of the pump 
operating cycle, the flow of ink from the pump assembly 40 appears to be 
relatively uniform. This is because a flow of ink from the pump assembly 
40 is established and maintained during the relatively long discharge 
portion of the pump operating cycle. A brief interruption in ink flow from 
the pump assembly 40 for the intake portion of the pump operating cycle 
causes only what appears to be a minor fluctuation in the pressure of the 
ink flow. Of course, this tends to promote a uniform supply of ink at the 
rail 36 (FIG. 2) and to enhance the quality of the material printed on the 
web 16. 
Although the intake portion of the pump operating cycle is of a relatively 
short duration, the velocity of the piston 54 varies greatly during the 
intake portion of the pump operating cycle. At the beginning and end of an 
intake stroke, the speed of movement of the piston 54 is relatively slow. 
However, during the relatively large central portion of the intake stroke, 
the piston 54 is moving very fast. Thus, the motor 44 is operated at a 
constant, high speed, during the intake stroke. In converting the constant 
speed rotational motion of the motor output shaft 50 to linear motion of 
the piston 54, the drive assembly 52 causes the speed of the piston and 
the rate of flow of ink into the pump assembly 40 to vary through a large 
range. 
During the relatively long duration of the discharge portion of the pump 
operating cycle, the speed of operation of the motor 44 is varied to 
maintain a constant rate of flow of ink from the pump assembly 40. Once 
the pump operating cycle has shifted from the intake portion to the 
discharge portion, the piston 54 moves through equal increments of 
distance relative to the cylinder 76 during equal increments of time. 
Thus, the speed of movement of the piston 54 remains constant during the 
discharge portion of the pump operating cycle. 
The illustrated main motor 44 is of the well known stepper type in which 
the motor is energized to move through incremental distances or steps. The 
speed at which each step of the motor occurs remains constant. However, 
the frequency of the steps is varied to vary the rate of operation of the 
motor. 
To obtain a high rate of ink flow into the pump assembly 40, the stepper 
motor 44 is operated to take steps at a very high frequency. To maintain a 
relatively low rate of flow of ink from the pump assembly 40, the stepper 
motor 44 is operated to take steps at a relatively low frequency. By 
operating the motor 44 to take steps at a high frequency during the intake 
portion of the operating cycle of the pump assembly 40 and by operating 
the motor to take steps at a low frequency during the discharge portion of 
the pump operating cycle, the intake portion of the pump operating cycle 
is of very short duration compared to the duration of the discharge 
portion of the pump operating cycle. Of course, other known types of 
variable speed motors could be utilized if desired. 
The rate of operation of the motor 44 is varied during the discharge 
portion of the pump operating cycle to maintain a constant flow rate of 
ink from the pump assembly 40. If the motor 44 is operated at a constant 
rate during the discharge portion of the pump operating cycle, the drive 
assembly 52 causes the speed of movement of the piston 54 would vary in a 
sinusoidal manner. Of course, this would result in variations in the rate 
of flow of ink from the pump assembly 40. 
To maintain a constant rate of flow of ink from the pump assembly 40 during 
the discharge portion of the pump operating cycle, the rate of operation 
of the motor 44 is varied to maintain the velocity of the piston 54 
constant. Since the piston 54 has a constant velocity, the piston moves 
through the same incremental distance for each unit of time. Therefore, 
the volume of ink discharged from the pump chamber 82 remains the same for 
each unit of time. 
During the intake portion of the pump operating cycle, the motor 44 is 
operated at a constant speed which is as fast as is practically possible. 
This results in the duration of the intake portion of the pump operating 
cycle being as short as is practically possible. Since the motor 44 is 
operated at a relatively high constant speed during the intake portion of 
a pump operating cycle, the speed of movement of the piston 54 varies 
sinusoidally during the intake portion of the pump operating cycle. The 
speed of movement of the piston and the flow of ink into the pump chamber 
82 will be a maximum when the piston is moving through a central portion 
of its operating stroke. The speed of movement of the piston 54 and the 
rate of flow of ink into the pump chamber 82 will be relatively low when 
the piston is adjacent to either end of its operating stroke. 
During the discharge portion of the pump operating cycle, the speed of 
operation of the motor is varied. However, the average speed of operation 
of the motor 44 during the discharge portion of the pump operating cycle 
is always substantially less than the average speed of operation of the 
motor 44 during the intake portion of the pump operating cycle. During the 
discharge portion of the pump operating cycle, the speed of operation of 
the motor 44 is the greatest when the piston 54 is adjacent to the 
opposite ends of its discharge stroke and is the least when the piston is 
adjacent to a central portion of its discharge stroke. Although the speed 
of operation of the motor 44 varies, the speed of movement of the piston 
54 remains constant during the discharge portion of pump operating cycle. 
One specific embodiment of a main motor control system 100 for controlling 
the speed of operation of the motor 44 is illustrated schematically in 
FIG. 3. The main motor control system 100 includes a data storage unit or 
memory 104. The data storage unit 104 stores data corresponding to 
multipliers by which a nominal speed of operation of the motor 44 must be 
varied to effect operation of the drive assembly to move the piston 54 at 
a constant speed during the discharge portion of a pump operating cycle. 
During operation of the printing press 10 at a constant speed, ink pump 
drive motors, corresponding to the motor 44, have previously been driven 
at a constant nominal speed. This constant nominal speed of motor 
operation has resulted in the ink pump piston being moved at a variable 
speed by the drive assembly. The data storage unit 104 contains data or 
multipliers by which the previous constant nominal speed of operation of 
the ink pump drive motor is varied during the discharge portion of the 
pump operating cycle to effect movement of the piston 54 at a constant 
speed. 
A density register 106 (FIG. 3) stores data which varies as a function of 
the ink density applied to a portion of the web supplied with ink by the 
pump assembly 40. Thus, the greater the ink density on the printed portion 
of the page supplied with ink by the pump assembly 40, the greater the 
speed of operation of the motor 44 to supply the demand for ink by the 
pump assembly. 
Although the operating speed of the motor 44 is varied during the discharge 
portion of a pump operating cycle to maintain a constant rate of flow of 
ink from the pump assembly 40, the rate of operation of the motor 44 is 
also varied as a function of press operating speed. Thus, a printing press 
speed input or reference signal is received by the motor control system 
100 from a tachometer (not shown) driven by the press drive system. The 
press speed reference signal is conducted over a lead 110 to the motor 
control system 100. 
A detector assembly 112 is provided in association with the pump drive 
motor 44 to detect the end of a discharge stroke and the beginning of an 
intake stroke of the pump assembly 40. In addition, the detector assembly 
112 detects the end of an intake stroke and the beginning of a discharge 
stroke of the pump assembly 40. 
A stepper motor driver 116 is connected, through suitable circuitry, with 
the data storage units 104 and 106 and with the press speed input signal 
conducted over the lead 110. During the intake portion of the pump 
operating cycle, the stepper motor driver 116 effects operation of the 
stepper motor 44 at a very high constant speed which is independent of ink 
density and press operating speed. During the discharge portion of a pump 
operating cycle, the stepper motor driver 116 effects operation of the 
motor 44 at a relatively low speed which is varied as a function of the 
speed multipliers stored in the register 104, a factor for ink density on 
the printed page as represented by data stored in the register 106, and a 
printing press speed signal conducted over the lead 110. It is 
contemplated that the speed of operation of the printing press will 
probably remain constant, at a selected speed, during most of the time the 
printing press is operated to print particular material. 
Operation 
Upon initiation of an intake stroke of the pump assembly 40, a dark or 
opaque area 120 on a disk 122 connected with the motor output shaft 50 
moves away from the sensor 112 and a light or transparent area 124 on the 
disk moves to the sensor assembly 112. The dark and light areas 120 and 
124 both extend for one-half of the circumference of the disk 122. The 
crank arm 58 (FIG. 3) extends through an opening (not shown) in the disk 
122. Both the crank arm 58 and disk 122 rotate together with the motor 
output shaft 50. 
When the light or transparent area 124 on the disk 122 moves to the sensor 
head 124, light from an LED is transmitted through the disk to a 
photodiode. A relatively high voltage signal is then transmitted over a 
lead 126 to indicate the initiation of the intake portion of the pump 
operating cycle. Many different types of sensors 112 could be used to 
detect the beginning and the end of the intake and discharge portions of 
the pump operating cycle. However, in one specific embodiment, the sensor 
112 was obtained from Texas Instruments of Dallas, Texas under the 
designation of a TIL 147A Optoelectronic Assembly. Of course, other known 
types of sensors could be used if desired. 
The high voltage intake signal on the lead 126 is transmitted through a 
diode 128 to a junction 130. During the intake portion of an operating 
cycle of the ink pump assembly 40, the voltage conducted over the lead 126 
through the diode 128 is always far greater than the voltage conducted to 
a second diode 132. Therefore, transmission through the diode 132 is 
blocked during the intake portion of the pump operating cycle. The high 
voltage of the signal conducted from the sensors 112 to the junction 130 
during the intake portion of a pump operating cycle is of a substantially 
greater magnitude than the maximum possible voltage signal which will be 
conducted to the diode 132. 
During the intake portion of the pump operating cycle, a relatively high 
voltage is conducted from the junction 130 to a multiplying 
digital-to-analog converter 136. The digital-to-analog converter 136 
multiplies the input voltage by a constant to still further increase the 
magnitude of the voltage. In one specific embodiment, the 
digital-to-analog converter 136 was obtained from Analog Devices of Two 
Technology Way of Norwood, Massachusetts under the designation of AD 7523 
Multiplying D/A Converter. However, other known types of digital-to-analog 
converters could be used if desired. 
The high voltage output from the digital-to-analog converter 136 is 
conducted to a voltage-to-frequency converter 140. In one specific 
embodiment, the voltage-to-frequency converter was obtained from Analog 
Devices of Two Technology Way of Norwood, Massachusetts under the 
designation of A/D 537 Voltage-to-Frequency Converter. However, it should 
be understood that other known types of voltage-to-frequency converters 
could be utilized if desired. 
The extremely high frequency output from the voltage-to-frequency converter 
140 is conducted to a count divider 144. The count divider 144 divides the 
relatively high frequency input by a factor, for example 256, to reduce 
the very high frequency to a range which can be used by the stepper motor 
driver 116. The output from the count divider 144 is transmitted to the 
stepper motor driver 116. 
The high frequency series of pulses from the count divider 144 effect 
operation of the stepper motor driver 116 to operate the pump drive motor 
44 at a relatively high speed. Thus, the time between pulses conducted to 
the stepper motor driver during an intake portion of a pump operating 
cycle is very short and the motor 44 drives the pump 40 as fast as is 
reasonably possible to minimize the duration of the intake portion of the 
pump operating cycle. In one specific embodiment, the stepper motor driver 
was obtained from SGS-Thompson of Phoenix, Arizona under the designation 
of GS-D200. Of course, other known stepper motor drives could be utilized 
if desired. 
During the intake stroke of the pump assembly 40, the motor 44 operates at 
a constant and very high rate which is substantially greater than any 
possible rate at which the motor is operated during a discharge portion of 
the pump operating cycle. Therefore, the intake portion of the pump 
operating cycle is of very short duration and the ink quickly flows into 
the pump chamber 82. Although the rate of operation of the motor 44 
remains constant during the intake portion of the pump operating cycle, 
the speed of movement of the piston 54 varies sinusoidally due to the 
action of the drive assembly 52. Therefore, although the intake stroke is 
of very short duration, the flow rate during the intake stroke varies from 
a minimum flow at the beginning and end of the intake stroke of the piston 
54 to a relatively large maximum flow rate as the piston is moving through 
the central portion of the intake stroke. 
The end of the intake portion of the pump operating cycle is detected by 
the detector assembly 112. During the intake portion of the pump operating 
cycle, the motor output shaft 50 rotates through 180.degree.. The disk 122 
rotates with the motor output shaft 50. At the end of the intake portion 
of the pump operating cycle, the light or transparent area 124 on the disk 
122 moves away from the sensor 112 and the dark or opaque area 120 moves 
to the sensor. As this occurs, the output voltage conducted over the lead 
126 from the sensor 112 immediately decreases to a relatively low value to 
indicate the beginning of the discharge portion of the pump operating 
cycle. 
The press operating speed voltage signal conducted over the lead 110 from a 
press driven tachometer to a digital-to-analog converter 148 is multiplied 
by an ink density factor conducted from a register 106. The ink density 
factor at the register 106 is set by a press operator to correspond with 
the density of the ink on the portion of the web supplied with ink by the 
pump assembly 40. The output from the digital-to-analog converter 148 is 
conducted to the diode 132. The digital-to-analog converter 148 is of the 
same construction as the digital-to-analog converter 136. 
During the discharge portion of the pump operating cycle, the output 
voltage from the digital-to-analog converter 148 will be substantially 
greater than the relatively low voltage conducted from the sensor 112 over 
the lead 126. Therefore, the relatively high output voltage from the 
digital-to-analog converter 148 is transmitted through the diode 132 to 
the junction 130 and blocks the transmission of the relatively low voltage 
through the diode 128. 
A counter 152 is reset by the change in the voltage on the lead 126 from a 
relatively high voltage to a relatively low voltage indicating the 
beginning of the discharge portion of the ink pump operating cycle. The 
second digital-to-analog converter 136 multiplies the reference voltage 
from the first digital-to-analog converter 148 by data transmitted from 
the register 104. The data transmitted from the register 104 is a 
multiplier by which the nominal speed signal voltage from the 
digital-to-analog converter must be multiplied to obtain the desired 
constant ink flow rate during the first increment of the discharge portion 
of the pump operating cycle. 
The output from the digital-to-analog converter 136 is changed to a 
frequency signal by the voltage-to-frequency converter 140. The frequency 
of this signal is reduced by the count divider 144. The first pulse from 
the count divider 144 is transmitted over a lead 154 to the counter 152 to 
step the counter to read data from the next data storage location in the 
register 104. In addition, the first pulse is transmitted to the stepper 
motor driver 116 to effect operation of the motor 44 through one step or 
increment. 
The change in the data transmitted from the register 104 to the 
digital-to-analog converter 136 changes the voltage transmitted to the 
voltage-to-frequency converter 140. Therefore, the frequency of the next 
pulse transmitted to the stepper motor driver 116 is changed. 
The foregoing steps are repeated to vary the speed of operation of the 
motor 44 in accordance with the data stored in the register 104 during the 
discharge portion of the pump operating cycle. The data stored in the 
register 104 is calculated so as to vary the rate of operation of the 
motor 44 to maintain the speed of movement of the pump piston 54 constant 
during the discharge portion of a pump operating cycle. Therefore, during 
the discharge portion of the pump operating cycle, a constant flow rate of 
ink is maintained from the pump assembly 40. 
During the discharge portion of the pump operating cycle, the motor 44 is 
operated through one-half of a revolution. Although the speed of operation 
of the motor 44 varies, the motor is operated at a relatively low rate so 
that the speed of movement of the piston 54 is relatively slow. This 
results in the discharge portion of the pump operating cycle being of a 
substantially greater duration than the intake portion of the pump 
operating cycle. 
Since the voltage signal conducted over the lead 110 to the 
digital-to-analog converter 148 varies in magnitude as a function of 
variations in press operating speed, the speed at which the motor 44 is 
driven during the discharge portion of the pump operating cycle is varied 
as a function of press operating speed. However, during the intake portion 
of the pump operating cycle, a relatively high and constant voltage 
conducted over the lead 126 from the sensor 112 effects operation of the 
motor 44 at a relatively high and constant speed to enable the intake 
portion of the pump operating cycle to be completed as fast is reasonably 
possible. Therefore, during the intake portion of the pump operating 
cycle, the speed of operation of the motor 44 is independent of press 
operating speed. 
The main motor control system 100 for controlling the speed of operation of 
only one of the motors 44 and associated pump assembly 40 is illustrated 
in FIG. 3. However, a motor control system 100 is provided in association 
with each of the motors 44 and pump assemblies 40. 
A main control assembly 160 is provided in association with the printing 
press 10. The main control assembly 160 (FIG. 3) can be manually actuated 
to transmit a stop signal over a lead 162 to interrupt operation of the 
stepper motor driver 116. In addition, the main press control assembly 160 
can be actuated to transmit a signal over a lead 164 to determine whether 
the motor 44 is driven in a clockwise or counterclockwise direction. In 
one specific instance, the control assembly 60 was an Intel 80286 
Microprocessor. However, other suitable control assemblies could be used 
if desired. 
Although one specific motor control system 100 has been described in 
conjunction with the motor 44, it should be understood that other known 
motor control systems could be used if desired. In fact, the ink pump 
assemblies 40 could have a substantially different construction and b 
driven directly from the main drive for the printing press. This would 
result in the elimination of the motor 44 and the motor control system 
100. 
Auxiliary Apparatus 
In accordance with a feature of the present invention, an auxiliary 
apparatus 200 (FIG. 1) is used in association with the printing press 10 
to supply ink to the printing press upon failure of a main pump assembly 
40 or 42 to supply ink to the ink rail 36 or 38 and while the failed pump 
assembly remains at a pumping station in the printing press. During normal 
operation of the printing press 10, the auxiliary apparatus 200 is kept at 
a remote location spaced from the printing press. Upon failure of a main 
pump assembly 40 or 42 to properly supply into to the ink rail 36 or 38, 
the auxiliary apparatus 200 is moved from the remote location to an 
operating location adjacent to the failed main pump assembly 40 or 42. 
Assuming that the main pump assembly 42 fails to operate, the auxiliary 
apparatus 200 is moved to an operating location adjacent to the 
malfunctioning main pump assembly 42, as shown in FIG. 1. An ink supply 
conduit 202 which normally connects main pump assembly 42 in fluid 
communication with the ink rail 38, is disconnected from the ink rail 38 
in the manner shown schematically in FIG. 1. Once the conduit 202 has been 
disconnected from the ink rail 38, the failed main pump assembly 42 is no 
longer connected in fluid communication with ink rail 38. After the failed 
main pump assembly 42 has been disconnected from the ink rail 38, the 
auxiliary apparatus 200 is connected with the ink rail 38 to supply ink to 
the ink rail. The failed main pump assembly (42) remains at a pumping 
station in the printing press (10) (FIG. 1). Thus, whenever one or more 
main pump assemblies break down and/or fail to operate correctly, the 
auxiliary apparatus 200 can be utilized to supply ink to the ink rail in 
place of the malfunctioning pump assembly or assemblies while the 
malfunctioning pump assembly or assemblies remains in the printing press 
(10). 
The auxiliary apparatus 200 is normally maintained separate from the 
printing press 10 at a remote storage location. Thus, the auxiliary 
apparatus 200 is normally disconnected from the ink rail 38 and from other 
components of the printing press. Upon a failure of a main pump assembly, 
such as the main pump assembly 42, the main pump assembly is stopped and 
disconnected from the ink rail 38. The auxiliary apparatus 200 is then 
connected with the ink rail 38. Thus, the connector 206 at one end of the 
conduit 202 normally connects the main pump assembly 42 with the ink rail 
38. Upon a failure of the main ink pump assembly 42 to operate correctly, 
operation of the main pump assembly is interrupted and the connector 206 
is then disconnected from the ink rail 38. 
Once the failed main pump assembly 42 has been stopped and disconnected 
from the ink rail 38, the auxiliary apparatus 200 is connected in fluid 
communication with the ink rail 38 through a conduit 210. Thus, a 
connector 212 at one end of the conduit 210 is connected with the ink rail 
38. The connector 212 has the same construction as the connector 206 so 
that the conduit 210 can be readily connected with the ink rail 38 in 
place of the conduit 202. Although the connectors 206 and 212 could have 
many different constructions, the connectors may be push-in fittings of 
the type which are commercially available from Legris of Rochester, New 
York. Of course, many other types of connectors, such as quick disconnect 
couplings, threaded couplings, etc. could be used if desired. 
The auxiliary apparatus 200 includes an auxiliary pump assembly 216. The 
auxiliary ink pump assembly 216 is connected with a drive motor 218. A 
motor control systems 222 is connected with the auxiliary motor 218 to 
control the speed of operation of the motor. 
It should be understood that the auxiliary apparatus 200 includes a 
plurality of auxiliary pump assemblies 216, motors 218, drive assemblies 
220 and control systems 222. Although only a pair of auxiliary pump 
assemblies 216, motors 218, drive assemblies 220 and control systems 222 
have been shown in FIG. 1, any desired number could be provided in the 
auxiliary apparatus 200. It is contemplated that the number of auxiliary 
pump assemblies 216, motors 218, drive assemblies 220 and control systems 
222 in the auxiliary apparatus 200 may be equal to the number of main pump 
assemblies 42 used to supply the rail 38 with ink. However, if only one of 
the main pump assemblies 42 fails to operate satisfactorily, only one of 
the auxiliary pump assemblies 216 would have to be connected with the ink 
rail 38. Of course, if a plurality of main pump assemblies 42 fail to 
operate satisfactorily, a corresponding number of the auxiliary pump 
assemblies 216 would be connected with the ink rail 38. 
The auxiliary pump assemblies 216, motors 218, drive assemblies 220 and 
motor control systems 222 have the same construction and mode of operation 
as the main pump assembly 40, motor 44, drive assembly 52 and motor 
control system 100 previously described herein. Thus, the auxiliary pump 
assembly 216 includes a piston which is reciprocated by operation of the 
drive assembly 220. The drive assembly 220 is driven by the motor 218 
which is of the well known stepper type. The motor control system 222 
varies the rate of operation of the motor 218 to drive the auxiliary pump 
assembly 216 through an operating cycle which includes an intake portion 
of relatively short duration and a discharge portion of relatively long 
duration. In addition, motor control system 222 varies the rate of 
operation of the pump drive motor 218 during the discharge portion of the 
operating cycle to maintain a constant rate of flow of ink from the 
auxiliary pump assembly 216. 
Although the auxiliary pump assembly 216 is operated to discharge ink at a 
constant rate during the discharge portion of the pump operating cycle, 
the rate of operation of the motor 218 during the discharge portion of the 
pump operating cycle is varied with variations in press speed. This is 
because the demand for ink varies with variations in press speed. However, 
during the short duration intake portion of the pump operating cycle, the 
drive motor 218 is always operated at the same relatively high rate. This 
is done in order to minimize the duration of the intake portion of the 
operating cycle of the auxiliary pump assembly 216 at all operating speeds 
of the printing press 10. 
The auxiliary motor control system 222 varies the speed of operation of the 
auxiliary motor 218 during the discharge stroke of the auxiliary pump 
assembly 216 as a function of variations in the operating speed of the 
printing press 10 and as a function of variations in the density with 
which ink is applied to the sheet material 16. Thus, the speed of 
operation of the motor 218 varies as a direct function of variations in 
the operating speed of the printing press 10. The greater the operating 
speed of the printing press 10, the greater is the demand for ink and the 
greater is the speed at which the motor control system 222 effects 
operation of the auxiliary motor 218 and auxiliary pump 216. 
The speed of operation of the auxiliary motor 218 also varies as a direct 
function of variations in the ratio of the area of the sheet material 16 
which is to be covered by ink to the total area of the sheet material. The 
greater the area of the sheet material which is to be covered by ink, the 
greater is the speed of operation of the auxiliary motor 218. Thus, the 
greater the density of the ink on the sheet material, the greater the 
speed of operation of the motor 218 to drive the auxiliary pump assembly 
216 to supply the necessary quantity of ink. 
The auxiliary apparatus 200 includes an auxiliary reservoir 226 for holding 
a supply of ink. Ink is conducted from the reservoir 226 to the auxiliary 
pump assembly 216 through an inlet conduit 228. Although it may be 
preferred to provide a separate reservoir 226 of ink to supply the 
auxiliary pump assembly 216, it is contemplated that the auxiliary pump 
assembly 216 could be connected with the source of ink from the main pump 
assembly 42. If this is to be done, a conduit would be provided to connect 
the auxiliary pump assembly 216 with the main ink supply reservoir for the 
printing press 10. The auxiliary pump assembly 216 may be connected with 
the main ink supply reservoir by disconnecting the supply conduit for a 
failed main pump assembly 42 from the main ink supply reservoir and 
connecting the supply conduit for the auxiliary pump assembly 216 with the 
main ink supply reservoir at the same connection. 
The motor control system 222 for the auxiliary pump assembly 216 is 
connected with controls 232 for the printing press 10 through an auxiliary 
apparatus controller 234. The controls 232 for the printing press 10 
provide the controller 234 with input signals corresponding to the speed 
of operation of the printing press 10 and the desired density of ink on 
the sheet material 16. The controller 234 could be mounted on a movable 
base or cart 238 along with the auxiliary pump assembly 216 and reservoir 
226 if desired. However, it is contemplated that it may be desired to 
mount the controller 234 on a separate movable base or cart so that the 
auxiliary pump assembly 216 can be moved to a location adjacent to a 
failed main pump assembly 42 while the controller 234 remains in an aisle 
separated by some distance from the auxiliary pump assembly 216. 
During operation of the auxiliary pump assembly 216 to supply ink to the 
ink rail 38, the auxiliary motor control system 222 effects operation of 
the auxiliary motor 218 to drive the auxiliary pump assembly in the same 
manner as in which the motor control system 100 effects operation of the 
main pump assembly 42. Therefore, ink is supplied by the auxiliary 
apparatus 200 to the ink rail 38 in the same manner as in which it was 
supplied by the main pump assembly 42 before the main pump assembly 
malfunctioned. 
Although it is preferred to connect the controller 234 for the motor 
control system 222 with the main controls 232 for the printing press 10, 
it is contemplated that for some printing presses it will be necessary to 
have the controller 234 function separately from the main controls for the 
press. If this is to be done, a tachometer pickup assembly 242 (FIG. 4) is 
temporarily mounted in engagement with a shaft 244 of the printing press. 
The shaft 244 is driven by the main press drive at a speed which varies as 
a function of variations in the speed of operation of the printing press. 
Therefore, an output signal transmitted from the tachometer pickup 
assembly 242 to the controller 234 will vary as a direct function of 
variations in the operating speed of the printing press. 
When the controller 234 functions separately from the main controls for a 
printing press, the controller is supplied with a separate input, either 
manually or by an electrical signal, which is indicative of the ink 
density on the sheet material 16. Of course, other methods of controlling 
the speed of operation of the auxiliary apparatus 200 as a function of 
printing press speed and density of ink on the sheet material 16 could be 
utilized if desired. 
Although it is preferred to have the auxiliary pump assembly 216 have the 
same construction as the main pump assembly 42, other known types of pump 
assemblies could be utilized if desired. It should also be understood that 
although it is preferred to drive the auxiliary pump assembly 216 with the 
motor 218 through a drive assembly 220 having the same construction as the 
drive assembly 52, the drive assembly 220 could have a different 
construction if desired. In addition, it should be understood that 
although it is preferred to utilize a motor control system 222 having the 
same construction as the motor control system 100, a motor control system 
having a different construction could be utilized if desired. 
CONCLUSION 
The present invention provides a new and improved auxiliary apparatus 200 
and method for supplying ink to a printing press 10 upon failure of a main 
ink pump 42. The auxiliary apparatus 200 includes a portable auxiliary ink 
pump 216 which is maintained separate from the printing press 10 during 
normal operation of the main ink pump 42. Upon failure of the main ink 
pump 42 to supply ink to the printing press 10, the auxiliary ink pump 216 
is moved from a remote location spaced from the printing press to an 
operating location (FIG. 1) adjacent to the failed main ink pump 42. A 
conduit 210 is provided to connect auxiliary ink pump 216 in fluid 
communication with the printing press 10. A motor 218 connected with the 
auxiliary ink pump 216 is then operated to drive the auxiliary ink pump to 
supply ink to the printing press 10 through the conduit 210.