GB1585452A

GB1585452A - Inking mechanism

Info

Publication number: GB1585452A
Application number: GB14802/78A
Authority: GB
Original assignee: Harris Corp
Current assignee: Harris Corp
Priority date: 1977-04-18
Filing date: 1978-04-14
Publication date: 1981-03-04
Also published as: JPS53133106A; FR2387775A1; CA1101731A; DE2816881A1

Description

(54) IMPROVEMENTS IN OR RELATING TO AN INKING MECHANISM (71) We, HARRIS CORPORATION, a corporation organised and existing under the laws of the State of Delaware, United States of America of 55 Public Square, Cleveland, Ohio 44113, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention relates to a mechanism for applying ink to a rotatable roll in a printing press.

The invention provides a mechanism for applying ink to a rotatable roll in a printing press, said mechanism comprising an ink rail extending axially of said roll, said ink rail having ink delivery and supply passages therein, means for supporting said ink rail in ink delivering relation to said rotatable roll, said ink rail including a plurality of axially spaced ink delivery stations, each of said stations including an ink applying section extending circumferentially around a part of the roll, a gear pump mounted on said ink rail at each of said stations and adapted to coact with said delivery station for forcing ink through a delivery passage in said ink rail to the surface of said ink rail for pickup by said rotatable roll, and a respective electric motor for driving each respective gear pump, said electric motors being mounted with said pumps on said ink rail.

In order that the invention may be well understood some embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is a view partially in section and partially broken illustrating a mechanism for applying ink to a rotatable roll in a printing press; Fig. 2 is an enlarged view taken approximately along the line 2-2 of Fig. 1; Fig. 3 is an enlarged fragmentary view of a portion of the structure shown in Fig. 1; Fig. 4 is a sectional view taken along line 4 4 of Fig. 3; Fig. 5 is an enlarged view taken approximately along the line 5-5 of Fig. 2; Fig. 6 is an enlarged view of a portion of Fig. 2; Fig. 7 is a view taken on the line 7-7 of Fig. 6; Fig. 8 is a schematic fluid circuit; Fig. 9 is a view in partial cross-section like Fig. 6 showing an alternative embodiment; Fig. 10 is a cross-sectional view of the ink rail as it appears in the plane indicated by the line 110 in Fig. 9; Fig. 11 is a cross-sectional view of the ink rail and pump assembly as it appears in the plane indicated by the line 11-11 in Fig. 9; Fig. 12 is a view partially broken away of a plurality of ink pumps; and Fig. 13 is a block diagram of an ink pump pulsing circuit.

The inking mechanism to be described is for depositing ink on a roll of an ink train of a printing press. Specifically, the described mechanism is of the type which is termed an ink rail in which ink is pumped into a rail which extends circumferentially around a portion of the ink roll. The roll strips the ink from the ink rail as the roll rotates.

The mechanism in particular provides an ink control module which is of a page pack size and is of a compact and unique design. It is constructed to enable easy and accurate column control of ink either by manual or automatic control It is relatively easy to maintain, has minimum hoses and fittings and has an automatic clean and purge system associated therewith.

As shown in Fig. 1, the mechanism is used to deliver ink to a rotatable roll or ink roller 10 forming a part of an ink train of a printing press. The structure illustrated in Fig. 1 is a conversion unit for use with an existing printing press. As a result, the roller 10 is driven from a motor 11 through a timing belt 13. The roller 10 could be driven from the gearing of the printing press but since the illustrated embodiment is a conversion unit for a printing press, a separate motor 11 is provided for driving the roller 10. The roller 10, of course, is in ink-transferring relationship with other rollers (not shown) in the ink train of the press, which rollers deliver ink to the plate cylinder of the printing press. The roller 10 commonly would run against a vibrator roll in the inking tram.

The roller 10 is supported at its opposite ends in bearings 14, 15 which are located in arms 16, 17, respectively. As shown in Fig. 1, arm 16 is located on the left side of the roller 10 and extends downwardly and is suitably fixed at its lower end to a frame member 20.

The arm 17 likewise extends downwardly and also is fixed at its lower end to the frame member 20. The inking mechanism for applying ink to the roller 10 includes means for supporting an ink rail in ink delivering relation to the roll in the form of an ink rail support or bridge, generaly designed 25. The ink rail support is located between the arms 16 and 17. The ink rail support 25 carries or supports a plurality of ink rails or page pack assemblies generally designated 26. The page pack assemblies 26 are supported in longitudinally spaced relation along the length of the roller 10. Each page pack assembly 26 is removably secured to the upper surface of the support rail 25 by a plurality of bolts 28 (shown schematically). Removal of the bolts 28 enables the entire page pack assembly to be manually lifed from the ink rail support 25.

When the page pack assemblies 26 are located and secured to the ink rail support 25, the page pack assemblies and support may be manually moved toward and away from the ink roll 10. Preferably, for this purpose a handle 30 is located at each axial end of the roller 10. Only one handle 30 is illustrated in the drawings on the left side of the roller 10. The handles 30 are fixedly connected to stub shafts 31, 32. The stub shafts 31, 32 are rotatably supported in openings in the arms 16, 17 respectively.

Movement of the handles 30 results in the shafts 31, 32 rotating about their axes relative to arms 16, 17. The shafts 31, 32 are fixedly connected to the ink rail support 25 and upon movement of the handles 30, the ink rail support 25 will pivot about the axis of the stub shafts 31, 32.

The ink rail support 25 may be secured in any position in which it is pivoted by means of suitable fastening arrangements, designated 40 and located at opposite axial ends of the roll 10. Only the fastening arrangement 40 at the left end of roll 10 is illustrated in detail on the drawings and will be described.

The fastening arrangement 40 at the right end of the roll is of identical construction.

The fastening arrangement 40 comprises a pin 41 which extends through a hole 43 in the arm 16 and into a curved slot 42 in support 25. The slot 42, best shown in Fig. 2, has a curvature with the center of the pin 31 being the center of the curvature. The pin 41 is threaded at one end and a threaded locknut 44 engages the pin 41. By threading the nut 44 into engagement with the pin 41, the ink rail can be secured in any given position as desired. From the above, it should be apparent that upon loosening of the locknut 44 and movement of the handle 30, the various page pack assemblies mounted on the ink rail support 25 can be moved toward or away from the ink roll 10. This movement being permitted by the fact that the pin 41 is located in the slot 42 in the arm 16 and thus does not interfere with such movement.

A suitable stop arrangement generally designated 50 is provided on both sides to prevent excessive movement of the page pack assemblies toward the roller 10. The stop arrangement (see Fig. 4) comprises a stop screw 51 which has a stop surface 52 for engagement with a surface of the arm 17.

The stop screw 51 is mounted and secured to an L-shaped plate 53 which has one leg of the L bolted to the ink rail support 25. The stop screw 51 is threaded into the other leg of the L.

When the ink support 25 moves toward and away from the roller 10 and the plate 53 and stop screw likewise move. When the surface 52 of the stop screw 51 engages the arm 17 movement stops. It should be clear by adjustment of screw 51 the inwardmost position of the page pack assemblies can be adjusted.

Each of the page pack assemblies 26 includes an ink applying section or portion 60 which extends circumferentially around a part of the roll 10 and is carried by a manifold portion 65 of the ink rail. The ink rail portion 60 has a plurality of axially spaced ink delivery stations including spaced passages 61 formed in the ink rail 60 and the sections are curved around the periphery of roller 10. The passages 61 are adapted to receive the ink as will be apparent from the description hereinbelow. Ink is delivered to the passages 61 through an outlet or ink delivery passage 70 in the ink manifold 65 from a gear pump 62 driven by a D.C. motor 63.

A plurality of gear pumps 62 is provided in each page pack. Each gear pump has an outlet or ink delivery passage 70.

Each outlet passage 70 (see Fig. 2) communicates with a horizontally extending ink delivery passage 80. The flow in the passage 80 is divided by a flow directing wedge 80c (Fig. 5) which directs the flow into two flows indicated by arrows 80a, 80b in Fig. 5. These flows are received in orifices 81, 82 located adjacent to the periphery of the roll 10. The roll 10 as it rotates past orifice 81, 82 rips the ink from the orifices 81, 82 and accelerates the ink flow from zero to press speed and carries the ink into the passageways 61. The wedge 80c extends circumferentially around the roll 10 and the ink delivered through orifices 81, 82 becomes deposited on the roll 10 in spaced strips. The vibrator roll in the ink train (not shown) acts to spread the ink longitudinally so that a film of ink is provided throughout the roll.

Each horizontally extending ink delivery passage 80 has a portion 80d located below the level of the orifices 81, 82 as best shown in Fig. 2. This portion 80d acts as a reservoir and pressure compensator and minimizes "bleeding" of ink onto the roll 10 if the press is stopped.

As noted hereinabove the ripping of the ink out of the orifices 81, 82 results in a substantial heating of the ink. The ink tends to adhere equally to the fast moving ink roll 10 and the ink rail surface and is split, with part of the ink moving with the roll and part moving u the ink rail surface. These actions also result in further heating of the ink making it quite fluid. In particular, the ink immediately adjacent to the ink rail surface is particularly subjected to heating due to friction between the ink and the rail surface.

This has resulted in the past in this fluid portion forming a bead at the end 74 of the ink applying section 60. This bead gradually increases in size until large enough and cooled enough to stick to the roller. When this bead releases from the ink rail 60 an excessive amount of ink flows through the system and a dark spot results on the print.

This problem may be minimized by providing an axially extended cavity 75 formed in the ink rail and specifically in each of the passages 61. The cavity 75 defines a pair of circumferentially spaced ink releasing gaps on the ink applying section. The cavity 75 reduces the formation of the bead on the leading end of the ink rail. This is believed to be due to the fact that the ink can cool in the reservoir provided by the cavity 75. As a result, the problem of a bead of ink releasing from the ink rail and moving down through the ink train is avoided.

The ink manifold 65 of each page pack assembly has the gear pumps 62 supported thereon. Specifically, the gear pumps 62 are supported on a surface 66a of the manifold 65. The manifold 65 of the embodiment shown in Figs. 2 and 6 has a common ink supply or inlet passage 65a which extends axially through the manifold 65. The common inlet passage 65a is adapted to receive ink from a suitable supply. A suitable valve 100 controls the flow of fluid into the common inlet passage 65a. Inlet passageways or ink supply passages 71 communicate with the common passage 65a and also communicate with the inlet of respective gear pumps 62. The gear pumps 62 draw ink from the inlet passageways 71 and force ink into the outlet or ink delivery passages 70.

As noted above, each gear pump 62 is mounted on a face or surface 66a of the ink manifold 65. In particular, the inlet passages 70 and outlet passages 71 intersect the same face 66a of the ink rail manifold 65. A port plate 90 for each gear pump 62 (see Fig. 7) engages the face 66a and ports fluid into and out of the pumping chamber of each gear pump 62. The port plate 90 includes an inlet port 91 and an outlet port 92. The pumps 62 and port plates 90 are fixedly secured on the face 66a of the manifold 65. Each pump 62 has its individual drive motor 63 to form a pump and motor unit.

Associated with each page pack 26 is a valve 100 which controls the flow of fluid into the common passage 65a of each page pack. The valve 100 is removably face mounted on the rail support 25. The valve has three inlets, 110, 111,112 and one outlet, 114 (see Fig. 8). The outlet 114 is adapted to communicate with a vertically extending passage 101 in the ink manifold 65 to deliver ink or fluid to the common passage 65a. The valve is face mounted on the face 102 of the rail support 25 which has a passage 103 communicating with the passage 101 in the ink manifold 65.

The inlet 110 (see Fig. 8) is in fluid communication with a supply 120 of black ink. The inlet 111 is in fluid communication with a supply 121 of colored ink. The inlet 112 is in fluid communication with a supply 122 of cleaning solvent.

Each valve 100 has a movable part 125 which can be moved to different positions in order to communicate either inlet to the outlet. The part 125 may be manually moved by a handle 126. Aso, the part 125 may be moved by a suitable stepping motor not shown.

Fig. 8 illustrates a system for a blanket to blanket perfecting press having upper and lower plate cylinders and thus upper and lower inkers. The inkers for the upper and lower printing units are designated top and bottom. As shown therein page pack assemblies 26 four in number are associated with the upper inking roller 10 and a plurality of page pack assemblies designated 26a are associated with the lower inking roller designated 10a. A valve 100 is associated with each page pack assembly and may be set to direct black ink to each page pack assembly or may be set to direct colored ink to each page pack assembly. For example, in the position of the valves 100 illustrated, the valve is directing black ink into the page pack assemblies.

As shown in Fig. 8 the inlet 110 communicates with the black ink supply 120 through conduit designated 130. Upon movement of a valve to a position where the inlet communicates with the outlet 114 the page pack assembly would then receive ink from the colored ink reservoir 121. Further by moving the valve to a position where the outlet 114 communicates with the inlet 112, cleaning solvent from the cleaning solvent reservoir 122 is directed through conduit 93 into the page pack assembly to effect a cleaning thereof.

The ink rail assembly includes means defining a trough 133. The trough receives solvent that runs off of the roll 10 during cleaning of the roll.

In Figs. 9-12 there is shown another embodiment of an ink rail. As indicated above, a problem sometimes encountered with a single manifold line or ink supply passage, e.g. the line 65a in Fig. 5 feeding several pumps, is starvation of certain of the pump units. Specifically, a pump unit remote from the ink inlet to the line may not receive a sufficient amount of ink because the other pumps draw off the ink before it reaches the remote pump.

To overcome this difficulty manifolding such as shown in Figs. 9-12 is used. In general, a central manifold is provided with individual conduits leading to individual ink pumps. Thus, the fluid pressure at entry into the individual conduits is close to the same for each pump, and no pump is starved.

As shown in Fig. 9, an inlet flow control valve 150 has a main inlet 152 for, say, black ink. A second fluid inlet 154 is conveniently provided for solvent (utilized in cleaning the ink rail and pumps), or for the substitution of a different color ink as described in connection with Fig. 8. The directional valve 150 is adapted for manual operation by a throw handle 156. The outlet from the valve 150 opens into a central manifold chamber or reservoir 158, in the ink rail 159.

Manifold chamber 158 is provided with eight outlets, e.g. 160, 161, 162, 163, 164, 165, 166 and 167. The eight outlets communicate with eight individual ink pumps of a page pack. Each of the outlets 16167 communicates with a respective individual conduit 168-175 extending from the manifold chamber 158 to the individual ink pumps.

Specifically, the opening 160 communicates with a series of internal bores or ink supply passages in the ink rail defining a conduit 168; opening 161 communicates with conduit 169; opening 162 communicates with conduit 170; opening 163 communicates with conduit 171 etc. Each of these conduits is connected with a respective pump.

The manifold chamber 158 is desirably centrally located on the ink rail 159. The isolated conduits 168, 169, then, are conveniently of the same length and lead to the opposite ends of the ink rail 159. Conduits 170, 171 are likewise of equal length albeit shorter than conduits 168, 169. The outlets of the conduits 168-175 are on the face 176 of ink rail 159 and are uniformly spaced and located for entry of ink or solvent issuing therefrom into the inlets of respective ink pumps, only six pumps being shown and designated 180--185. It will be understood that an individual ink pump is provided for each column, and that the number of columns usually 8 to a page pack is a matter of choice.

Also provided in ink rail 159 are individual bores or feed conduits communicating the pump outlet with a horizontally extending passage 80 as in the embodiment of Fig.

6. The outlets shown in the drawings are designated 186, 187, 188. The other outlets are not shown.

The ink pumps, e.g. pumps 180185 are face mounted on the face 176 of ink rail 159 with their inlet and outlet ports in juxtaposed registry with the conduits in the ink rail. The pump inlets communicate with a respective passage 168--175 and the pump outlets communicate with passages such as 186188. Thus, each pump is provided with its own supply of ink from a common manifold chamber 158 and delivers ink through a feed conduit having the same length as every other feed conduit. A pump that is running at a relatively high speed due to high ink demand will not now cause ink starvation for an adjacent pump. Better delivery of ink is obtained in this way resulting in better ink control, particularly at the ends of the ink rail.

The speed of each ink pump motor is individually controllable and the quantity of ink delivered for any given printed column can be adjusted in accordance with the ink desired for that column by adjusting the speed of the motor. This adjustment can be made automatically or manually. Still further, as the speed of the press varies, the amount of ink supplied a given pump may be varied in direct linear proportion.

Experiments have shown that the average ink volume requirement on each column of a newspaper at a minimum press speed of 500 ft/min. is in the range of from 2-8cc of ink/minute. For commercial application, flow requirements may be as low as 0.1 cc/min. per pump. Only one pump on the page pack of 8 pumps may be running at such a delivery rate. Others may be off entirely or running at a higher rate. The range required for commercial use is from 0.1 to 60 cc/min. Under such extreme requirements, a further problem occurs with D.C. drive motors for the pumps. With common D.C. motors driving the gear pumps for feeding the ink, the lowest reason able speed is about 500 RPM. Below this value, the motor stalls or runs erratically and control is lost.

In order to avoid any stalling of the motor at lower rpm's and still provide for a continuous output from the gear pump, a pulsing circuit, as shown in Figure 13, is preferably utilized for driving the individual motors for the pumps.

The pulsing circuit is constructed so that each motor is energized by periodic pulses for a contant period so that its pump, during each period, delivers a predetermined constant amount of ink. Increases or decreases in the amount of ink required from a given pump are provided by controlling the interval between pulses. An arrangement for accomplishing such control and enabling control of ink over a wide range of flow rate is shown in FIGURE 13.

As shown there, each motor 200 is energized by a drive circuit 202 during the period of a one-shot 205. The one-shot is fired at intervals determined by the repetition rate of pulses from a voltage controlled oscillator 207. The input to voltage controlled oscillator 207 is from an individual pump potentiometer 210. The control voltage for potentiometer 210 as well as for corresponding potentiometers of the remaining pumps for the same page pack is provided by amplifier 214. The portion of the control voltage selected by wiper 215 of the potentiometer may be determined for each pump individually to establish a base flow rate for that pump in a given run. The input to amplifier 214 is from a page pack potentiometer 217 which may be set to provide a common base flow rate signal for the set of eight page pack pumps. The control voltage to potentiometer 217 is from the press tachometer 220 and that signal is provided to all page pack potentiometers.

In operation, potentiometers 217 and 210 will be set according to the requirements for ink flow rate from the block of page pack pumps and the individual pump 200, respectively. Voltage controlled oscillator 207 includes an integrator 223 which produces a ramp signal having a slope proportional to the signal at its input. When the signal reaches a predetermined value a Schmitt trigger 225 is fired and discharges integrator 223 as well as firing one-shot 205. The oneshot produces a pulse of predetermined time duration to drive motor 200 through drive circuit 202.

A change in the speed of the press will produce a corresponding change in the output of amplifier 214 and the input to voltage controlled oscillator 207. This change results in a corresponding change in the repetition rate of pulses to one-shot 205 and in the intervals at which motor 200 is energized.

At relatively high press speeds and/or at key settings requiring relatively high output from a gear pump, the pulses delivered to the drive circuit 202 for that gear pump will be at such a rate that the motor 200 will operate in substantially a continuous manner and will drive the gear pump with which it is associated in a continuous manner, and therefore a continuous flow of ink will flow from the gear pump. At low press speeds and/or key settings requiring a small amount of ink from the gear pump associated with a particular motor, the motor will be operated in a pulsed manner so that the flow from the gear pump with which the motor is associated will be in pulses. However, there will be a sufficient supply of ink for delivery in a continuous manner to the roll so that the proper quantity of ink is supplied to the roll.

It will be appreciated that the abovedescribed mechanism for applying ink to a rotatable ink roll is not as cumbersome in construction and heavy as previously proposed designs. The described mechanism also avoids the disadvantages associated with the use of piston pumps which because of their weight are commonly mounted off the ink rail and thus require relatively large conduits or hoses and fittings to deliver the ink to the roll. In addition piston-type pumps even if mounted on the ink rail deliver a pulsing flow of ink to the ink roll rather than a continuous even flow of ink. Also the stroke adjustments are cumbersome and relatively complicated mechanisms are involved.

WHAT WE CLAIM IS: 1. A mechanism for applying ink to a rotatable roll in a printing press, said mechanism comprising an ink rail extending axially of said roll, said ink rail having ink delivery and supply passages therein, means for supporting said ink rail in ink delivering relation to said rotatable roll, said ink rail including a plurality of axially spaced ink delivery stations, each of said stations including an ink applying section extending circumferentially around a part of the roll, a gear pump mounted on said ink rail at each of said stations and adapted to coact with said delivery station for forcing ink through a delivery passage in said ink rail to the surface of said ink rail for pickup by said rotatable roll, and a respective electric motor for driving each respective gear pump, said electric motors being mounted with said pumps on said ink rail.

2. A mechanism as claimed in claim 1, wherein said ink supply and ink delivery passages intersect the same face of said ink rail, and said gear pumps are mounted on said face of said ink rail.

3. A mechanism as claimed in claim 1 or 2, wherein each electric motor is directly connected to its respective gear pump to define a pump and motor unit.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. able speed is about 500 RPM. Below this value, the motor stalls or runs erratically and control is lost. In order to avoid any stalling of the motor at lower rpm's and still provide for a continuous output from the gear pump, a pulsing circuit, as shown in Figure 13, is preferably utilized for driving the individual motors for the pumps. The pulsing circuit is constructed so that each motor is energized by periodic pulses for a contant period so that its pump, during each period, delivers a predetermined constant amount of ink. Increases or decreases in the amount of ink required from a given pump are provided by controlling the interval between pulses. An arrangement for accomplishing such control and enabling control of ink over a wide range of flow rate is shown in FIGURE 13. As shown there, each motor 200 is energized by a drive circuit 202 during the period of a one-shot 205. The one-shot is fired at intervals determined by the repetition rate of pulses from a voltage controlled oscillator 207. The input to voltage controlled oscillator 207 is from an individual pump potentiometer 210. The control voltage for potentiometer 210 as well as for corresponding potentiometers of the remaining pumps for the same page pack is provided by amplifier 214. The portion of the control voltage selected by wiper 215 of the potentiometer may be determined for each pump individually to establish a base flow rate for that pump in a given run. The input to amplifier 214 is from a page pack potentiometer 217 which may be set to provide a common base flow rate signal for the set of eight page pack pumps. The control voltage to potentiometer 217 is from the press tachometer 220 and that signal is provided to all page pack potentiometers. In operation, potentiometers 217 and 210 will be set according to the requirements for ink flow rate from the block of page pack pumps and the individual pump 200, respectively. Voltage controlled oscillator 207 includes an integrator 223 which produces a ramp signal having a slope proportional to the signal at its input. When the signal reaches a predetermined value a Schmitt trigger 225 is fired and discharges integrator 223 as well as firing one-shot 205. The oneshot produces a pulse of predetermined time duration to drive motor 200 through drive circuit 202. A change in the speed of the press will produce a corresponding change in the output of amplifier 214 and the input to voltage controlled oscillator 207. This change results in a corresponding change in the repetition rate of pulses to one-shot 205 and in the intervals at which motor 200 is energized. At relatively high press speeds and/or at key settings requiring relatively high output from a gear pump, the pulses delivered to the drive circuit 202 for that gear pump will be at such a rate that the motor 200 will operate in substantially a continuous manner and will drive the gear pump with which it is associated in a continuous manner, and therefore a continuous flow of ink will flow from the gear pump. At low press speeds and/or key settings requiring a small amount of ink from the gear pump associated with a particular motor, the motor will be operated in a pulsed manner so that the flow from the gear pump with which the motor is associated will be in pulses. However, there will be a sufficient supply of ink for delivery in a continuous manner to the roll so that the proper quantity of ink is supplied to the roll. It will be appreciated that the abovedescribed mechanism for applying ink to a rotatable ink roll is not as cumbersome in construction and heavy as previously proposed designs. The described mechanism also avoids the disadvantages associated with the use of piston pumps which because of their weight are commonly mounted off the ink rail and thus require relatively large conduits or hoses and fittings to deliver the ink to the roll. In addition piston-type pumps even if mounted on the ink rail deliver a pulsing flow of ink to the ink roll rather than a continuous even flow of ink. Also the stroke adjustments are cumbersome and relatively complicated mechanisms are involved. WHAT WE CLAIM IS:

1. A mechanism for applying ink to a rotatable roll in a printing press, said mechanism comprising an ink rail extending axially of said roll, said ink rail having ink delivery and supply passages therein, means for supporting said ink rail in ink delivering relation to said rotatable roll, said ink rail including a plurality of axially spaced ink delivery stations, each of said stations including an ink applying section extending circumferentially around a part of the roll, a gear pump mounted on said ink rail at each of said stations and adapted to coact with said delivery station for forcing ink through a delivery passage in said ink rail to the surface of said ink rail for pickup by said rotatable roll, and a respective electric motor for driving each respective gear pump, said electric motors being mounted with said pumps on said ink rail.

4. A mechanism as claimed in claim 3,

wherein said individual pump and motor units are each provided with a port plate which is secured to said ink rail and includes an inlet port and outlet port.

5. A mechanism as claimed in any one of the preceding claims, wherein said ink rail has a common ink supply inlet passage therein and other ink supply passages communicate fluid from said common passage to an inlet port of each said gear pump, and the mechanism further includes a valve for controlling the flow of fluid into said common passage, said valve having a plurality of inlets adapted to be connected to different fluid supplies and said valve having a movable valve part for selectively communicating one of said inlets with the outlet of said valve.

6. A mechanism as claimed in claim 5, wherein said valve is removably secured to said means for supporting said ink rail.

7. A mechanism as claimed in claim 5 or 6, wherein said valve has one inlet for communication with a supply of solvent for cleaning the roll, and wherein said ink rail includes a trough for receiving solvent that flows from said roll.

8. A mechanism as claimed in any one of the preceding claims, wherein each ink applying section includes an orifice for receiving ink from a respective pump, and which orifice is located adjacent the periphery of said roll, the roll ripping the ink out of said orifice as the roll rotates relative thereto, and a cavity located in said ink applying section into which ink moves after being ripped from said orifice by said roller and which provides a reservoir enabling the ink to cool therein prior to reaching the end of said ink applying section.

9. A mechanism as claimed in claim 8, wherein the ink supply passages in said ink rail direct ink from a supply to said pumps, and ink delivery passages in said ink rail deliver ink from said pumps to their respective orifices.

10. A mechanism as claimed in claim 1, wherein each said ink applying section includes an axially extending cavity defining a pair of circumferentially spaced ink releasing gaps with said rotating roll and into which cavity ink moves after being sheared from said ink rail by said roll and traversing the first of said pair of gaps, and which cavity provides a reservoir enabling the ink to cool therein prior to passing through the second of said gaps in response to rotation of said rotatable roll.

11. A mechanism as claimed in any one of claims 1 to 4, wherein said ink rail includes means defining a manifold chamber communicating with an ink supply, each of said pumps being spaced a different distance from said manifold chamber, said individual supply passages in said ink rail conducting ink from said manifold chamber to said individual pumps, respectively, each of said pumps having an inlet and only one pump inlet being connected with an ink supply passage, and individual ink delivery passages in said ink rail for delivering ink to said ink applying sections from each of said pumps.

12. A mechanism as claimed in claim 11, additionally including means for controlling the ink delivery rate from said individual pumps.

13. A mechanism as claimed in claim 12, wherein said control means are responsive in direct relation to the speed of the press.

14. A mechanism for applying ink to a rotatable roll in a printing press substantially as herein described with reference to Figures 1, 3, 4, 8 and 13 and either Figures 2, 5, 6 and 7 or Figures 9 to 12.