EP0008924A1

EP0008924A1 - Apparatus for providing ink feed to printing presses

Info

Publication number: EP0008924A1
Application number: EP79301768A
Authority: EP
Inventors: John C. Hovekamp
Original assignee: Bangor Punta Corp
Current assignee: Bangor Punta Corp
Priority date: 1978-09-05
Filing date: 1979-08-29
Publication date: 1980-03-19
Also published as: MX153747A; BR7905718A; CA1133756A

Abstract

The invention relates to apparatus for providing ink feed to a printing press.

An inking-unit attachment for a printing press includes a fountain roller (30), a ductor roller (32) for rocking movement between the fountain roller (30) and a receiver roller (34) an idler roller (28) in the nip between the receiver roller (34) and an oscillator roller (26), and a pair of form rollers (22) for transferring ink from the oscillator roller (26) to the plate cylinder (20) of the printing press.

The receiver (34) and oscillator rollers (26) rotate at different peripheral speeds to provide a skidding action between one or both of such rollers and the idler roller (28) to provide an even distribution and an increased quantity of ink to the oscillator roller.

A three-function cam serves to reciprocate the oscillator roller (26) in an axial direction, rock the ductor roller (32) between positions in engagement with the fountain (30) and receiver (34) rollers respectively, and intermittently to drive the fountain roller (301. The form rollers (22) are movable between a position in the nip between the oscillator roller (26) and plate cylinder (201, a position spaced from the plate cylinder (20) and engaged with the oscillator roller (26), and a lift position spaced from both the plate cylinder and oscillator roller. The inking-unit attachment (18) is adapted to be releasably hung on the frame of the printing press (10) and to be driven from the plate-cylinder gear on the printing press through a shaft affixed to the plate-cylinder frame, where the shaft has an overload clutch to guard personnel from injury and the unit from damage

Description

The present invention relates to apparatus for providing ink feed for printing presses. More particularly, this invention relates to ink-feed devices for printing presses useful in direct and offset lithography.
Multicoloured offset presses in some cases employ a common blanket cylinder disposed in a main frame..Plate cylinders are conventionally arranged in a planetary manner about the common blanket cylinder, and each plate cylinder is provided with its own inking unit. Thus, the inking units transfer inks of selected colours to their associated plate cylinders which, in turn, transfer the inks to the blanket cylinder.
Gears from the blanket cylinder are employed to drive the plate cylinders and the rollers of the inking units. The inking units, plate cylinders and drive mechanisms therefor conventionally are attached to the main frame of the printing press.
In the conventional arrangement for inking units now employed, the unit is disposed on the circumfer.ence,of the plate cylinder, with the plate-cylinder gear driving the inking unit through the form-roller gear, or through a gear on a common shaft with the form roller. This arrangement provides the proper direction and speed for the form roller and the balance of the unit, but it has certain inherent disadvantages.
A common method used to secure the inking unit to the press is a bolt with adjustment means, adapted to be secured to both the press and the inking unit. If the operator determines that the pressure of the form roller on the plate cylinder is too little, he can adjust the bolts to increase that pressure, by urging the unit into closer contact with the plate cylinder. However, in so doing, the gears must necessarily be brought closer together. If the original spacing of the gears was correct, their closer proximity could then cause increased wear and possibly incresed frictional loss in the main press drive. If the form-roller pressure on the plate cylinder is too high, it can be decreased by backing the unit away from the main frame slightly. Again, initially correct drive gear spacing could then be lost; in the latter case, gear play and backlash could then approach unacceptable limits, also resulting in excessive gear wear, but not any appreciable frictional loss.
For multicolour presses, a number of units can be affixed to the press, in order to provide inks of different colours; or for other desired functions. The problems associated with a single inking unit in combination with a press will be multiplied when a number of such units are affixed to it. Thus, if all four inking units on a press are found to have the form rollers exerting insufficient pressure, subsequent adjustment to achieve the correct pressure could have the effect described above, with a resultant unnecessary frictional drag on the press mechanism. Further, the braking effect of the fountain roller can be transmitted to the press mechanism through the gear train, adding more drag to the entire apparatus.
Obviously, there is a point beyond which the physical interposition of the plate-cylinder gear and the form-roller gear will prevent any closer approach of the form roller on the side where the two gears mesh. However, the other end of the form roller is not under such constraint, and can approach the plate cylinder more closely. Nevertheless, the problems of securing adjustment of the inking unit on the press are clearly not just those of adjusting four units, but both sides of each unit, until good printing copy is achieved.
Where an inking unit is removed for any reason, such as repair, routine maintenance, cleaning or replacement, the removal itself destroys the adjustment, and when the same or a different unit is placed back on the press, the process of adjustment has to be followed for both sides of the unit.
Existing inking units function adequately to perform the task of supplying ink to a press, but the time between when the press is started and when the ink reaches the plate cylinder is longer than is desirable. After initial adjustments are made for the supply of ink to the fountain roller, it may require many revolutions of the plate cylinder to bring enough ink to it to determine whatever further fine adjustments may be needed, and a similar, though somewhat shorter, time to effect the individual fine adjustments until the ink feed from a given unit is correct.
A problem which has plagued inking units, and the printing industry, for a considerable time is more precisely defined as a two-component problem, with complementary aspects: contamination of the ink, and the image produced thereby, with lubricant, and contamination of the lubricant with ink, with resultant detrimental effects on the lubricating properties necessary to maintain the unit in proper condition. No completely satisfactory solution to these related problems has yet been found.
There are any number of devices for supplying ink to a printing press known in the art; the problem of proper supply is one which has received much attention. For instance, Dahlgren et al., in U.S. Patent No. 4,041,864, disclose an inking unit having a metering device and doctor-blade means for controlling ink-film thickness. While the Dahlgren device performs the functions for which it was designed, it has the disadvantage of being rather complex.
Other devices are known, such as Brackett, U.S. Patent No. 3,593,659, and Keller, U.S. Patent No. 2,185,342, for supplying ink to printing presses. However, no devices are known which have,the advantage of easy detachability and replacement.
According to the present invention there is an apparatus for providing ink to a printing press, comprising a frame having attachment means thereon;

a fountain roller;
a ductor roller;
a receiver roller;
an idler roller;
an oscillator roller; and
at least one form roller
said rollers being disposed within said frame; said receiver rollers and oscillator roller being driven from a drive source, and said fountain roller being intermittently driven from said drive source, said ductor roller, idler roller and form roller being driven frictionally by direct or sequential contact with said receiver roller or oscillator roller, or by direct or sequential contact with a plate cylinder of said printing press.

Preferably said fountain roller is adjustably indexed.
Preferably said ductor roller intermittently contacts first said fountain roller and then said receiver roller.
The receiver roller and said oscillator roller may operate at different rotational speeds, e.g. from 50% to 150% of the rotational speed of said oscillator roller, and preferably from 90% to 120%, with an optimum of 107%.
The fountain roller may be adjustably indexed, said ductor roller intermittently contacts first said fountain roller and then said receiver roller, said oscillator roller reciprocates axially, the indexing of said fountain roller, intermittent contact of said ductor roller and reciprocation of said oscillator roller being simultaneously driven by a three-function cam.
Additionally, an important feature of the present invention provides for uniform ink distribution and increased ink flow from the fountain roller to the form rollers and consequently to the plate and blanket cylinders. In the present invention, ink is transferred in sequence from a fountain roller to a ductor roller, a receiver roller, an idler roller, an oscillator roller and then to at least one, and generally a pair of form rollers for transfer to the plate cylinder. To accomplish uniform distribution of ink and increased ink flow, the peripheral speed of the receiver and oscillator rollers are preferably different one from the other such that a skidding action occurs between one or both of those rollers and the idler roller which is adjustably held in the nip of the receiver and oscillator rollers in surface contact therewith. The receiver roller most preferably has a peripheral speed'of approximately 107% of the peripheral speed of the oscillator roller, whereby a skidding action at the interface of the.receiver and idler rollers and/or the idler and oscillator rollers or both is achieved. The peripheral speed of the receiver roller may, however, range from 50% to 150% of the peripheral speed of the oscillator roller to achieve the skidding effect, and preferably, the receiver roller should rotate at a peripheral speed of 90% to 120% of the peripheral speed of the receiver roller. Although the 107% speed differential is most preferred, the result in any case provides uniform distribution of ink on the form rollers and minimizes ink starvation or ghosting. The precise mechanism of the improved effect resulting in uniform distribution of ink and prevention of ink starvation is not known; it is sufficient to note, however, that the mechanism of the present invention is effective in significantly reducing former problems of the control of ink feed which have heretofore led to starvation and ghosting.
A feature of the present invention resides in a unitary cam which reciprocates the oscillator roller in an axial direction, rocks the ductor roller to transfer ink from the fountain roller to the receiver roller, and indexes the fountain roller. This is achieved by a three-function cam driven by gearing on the inking-unit attachment which, in turn, is driven from a gear of the printing press, most frequently the plate-cylinder gear.
The inking-unit attachment of the present invention comprises a frame, a fountain roller carried by the frame for rotation about its axis, means carried by the frame for supplying ink to the fountain roller, a receiver roller carried by the frame for rotation about an axis parallel to the axis of rotation of the fountain roller and means for transferring ink from the fountain roller to the receiver roller, including a ductor roller rotatable about an axis parallel to the axes of rotation of the fountain roller and the receiver roller and in surface contact with the fountain roller and the receiver roller whereby ink is transferable in sequence from the fountain roller to the ductor roller, to the receiver roller, to an idler roller, then to an oscillator roller and then to at least one form roller for transfer to the plate cylinder of a printing press, the ink-transfer means including means for rotating at least one of the rollers at a peripheral speed different from the peripheral speed of another of the rollers in surface contact with the one roller to provide a skidding action between the contacting surfaces of the latter two rollers.
In accordance with another aspect of the present invention, the inking-unit attachment for a printing press having a plate cylinder comprises a frame, a form roller carried by the frame, means for supplying ink to the form roller including a plurality of rollers in ink-transfer relation one to the other and to the form roller, and means carried by the inking-unit attachment for releasably securing it to the printer with the form roller in ink-transfer relation to the plate cylinder carried by the printing press.
In accordance with a still further aspect of the present invention, the apparatus for supplying ink to a printing press comprises a frame including a pair each of inner and outer frame plates spaced one from the other and defining a pair of outer compartments and an intermediate compartment, a fountain roller carried by the frame and disposed in the intermediate compartment, the fountain roller being carried by the frame for rotary indexing movement, a receiver roller carried by the frame and disposed in the intermediate compartment, a ductor roller carried by the frame and disposed in the intermediate compartment, the ductor roller being carried by the frame for rocking movement between positions engaging the fountain roller and receiver roller for transferring ink from the fountain roller to the receiver roller, an oscillator roller-carried by the frame and disposed in the intermediate compartment, the oscillator roller being carried by the frame for axial reciprocating movement, an idler roller carried by the frame and disposed in the intermediate compartment in surface engagement with the receiver roller and the oscillator roller for transferring ink from the receiver roller to the oscillator roller, means carried by the frame in one of the outer compartments for driving the receiver roller and the oscillator roller, and unitary means coupled to the drive means and carried by the frame in one of the compartments for indexing the fountain roller, rocking the ductor roller, and reciprocating the oscillator roller.
A pair of side-plate extensions is provided for rigid attachment to the printing press, generally to the plate-cylinder frame. The side-plate extensions have an upper recess into which a coupling means of the attachment fits, and a lower stop means against which a lower brace rests. A shaft is disposed between the side-plate extensions, and is driven by a gear on the shaft in mesh with the plate-cylinder gear. Another gear on the same shaft is disposed to drive the oscillator and receiver roller through gearing in the inking-unit attachment. An overload clutch on the shaft disposed between the side-plate extensions is connected with either gear on the shaft in such fashion that the mechanism of the inking-unit attachment may be stopped while the plate-cylinder gear continues to move; without injury to personnel or machinery.
The coupling means, lower brace and the shaft disposed between the side-plate extensions are juxtaposed in a fashion which requires that the inking-unit attachment be raised from the rear in a hinging manner to remove it from the printing press. In the act of raising the rear of the attachment, the driven gear in the attachment is moved away - from the driving gear on the shaft disposed between the side-plate extensions. It is thus impossible to remove the attachment without first disconnecting the power; it is also impossible to connect the attachment while it is running, because the driving and driven gears cannot mesh until the lower brace of the attachment is virtually in contact with the lower stop means of the side-plate extensions.
The side-plate extensions are adjustable to permit proper spacing of the pitch diameters of the plate-cylinder gear and the gear on the shaft disposed between the side-plate extensions. The spacing of the upper recess, lower stop means, coupling means, lower brace and the driving and driven gears between the side-plate extensions and the attachment is chosen to cause the pitch diameters of the driving and driven gears to mesh at the optimum when the attachment is affixed to the side-plate extensions.
In the accompanying drawings:-

Figure 1 is a fragmentary top elevation with parts broken away of a printing press having an inking-unit attachment disposed thereon;
Figure 2 is an enlarged cross-section of the inking-unit attachment, taken generally along line 2-2 in Figure 1;
Figure 3 is an enlarged schematic illustration of the relative arrangement of the various rollers forming the inking-unit attachment hereof, and including a portion of the plate cylinder of the printer;
Figure 4 is an enlarged schematic illustration of the gearing arrangement for driving the rollers and the three-function cam;
Figure 5 is an enlarged fragmentary top plan of the attachment with portions of the rollers broken away for ease of illustration;
Figure 6 is a fragmentary enlarged side elevation of the attachment illustrated in Figure 5 with parts thereof in cross-section;
Figure 7 is a perspective view of the three-function cam;
Figure 8 is an enlarged fragmentary side elevation of an adjustment and positioning mechanism for the form rollers of the inking-unit attachment hereof;
Figure 9 is an enlarged fragmentary cross-section of the adjustment and positioning mechanism taken generally along line 9-9 in Figure 8;
Figure 10 is a fragmentary side elevational view with portions broken way illustrating the positioning mechanism for the form rollers in an "on" condition;
Figure 11 is a fragmentary cross-section of a portion of the positioning mechanism of Figure 9, taken generally along line 11-11 in Figure 9;
Figure 12 is a view similar to Figure 10 illustrating the positioning mechanism in an "off" condition;
Figure 13 is a view similar to Figure 11 illustrating the positioning mechanism in the off condition;
Figure 14 is a view similar to Figure 10 illustrating the positioning mechanism in a "lift" conaition;
Figure 15 is a view similar to Figure 11 illustrating the positioning mechanism in the lift condition;
Figure 16 is a cross-sectional view of the attachment taken generally along line 16-16 in Figure 9; and
Figure 17 is a fragmentary side elevation similar to Figure 10 and illustrating the adjustment mechanism;
Figure 18 is a side elevation showing the attachment means and the gear drive of the present invention;
Figure 19 is a fragmentary top elevation showing the gear drive and the overload clutch of the present invention.

In Figure 1 is shown a printing press, generally designated 10, having a central blanket cylinder 12 disposed in a main frame 14. Frame 14 has a spaced side frame plate 16 which extends from the central frame 14 housing blanket cylinder 12. Side frame plate 16 houses a plate cylinder 20, as well as devices, described in detail hereinafter, for releasably attaching an inking-unit attachment, generally designated 18, to the printing press. A plurality of the inking-unit attachments 18 may be hung from the central frame 14; but the operation of the present invention is independent of the number of inking-unit attachments secured to the press.
Each inking-unit attachment 18 is designed to apply a specified colour of ink to the plate cylinder disposed between it and the blanket cylinder 12. Thus, blanket cylinder 12, in the illustrated form, can pick up a four-colour image from four plate cylinders as it rolls in contact with the plate cylinders. The blanket cylinder 12 then applies this wet-ink multi-coloured image to an object to be printed by rolling contact between it and the object. For example, a bottle or a can lid may be disposed on a conveyor, not shown, below blanket cylinder 12 such that the multi-coloured inking images carried by blanket cylinder 12 can be applied directly by rolling contact with the items as they move in contact with blanket cylinder 12, for example, along a conveyor, not shown, in the direction indicated by the arrow C.
In Figures 3 and 4, the relative arrangement of the various rollers and other elements of one of the inking-unit attachments 18 of the present invention is illustrated. Particularly, form rollers 22, spaced one from the other, are disposed for engagement with the corresponding plate cylinder 20 on the side thereof opposite blanket cylinder 12, as shown in Figure 1, when attachment 18 is applied to printing press 10. In the nip of form rollers 22 and on the side of form rollers 22 opposite plate cylinder 20 is an oscillator roller 26. An idler roller 28 bears in the nip of oscillator roller 26 and a receiver roller 30 spaced from oscillator roller 26 on the opposite side thereof from form rollers 22. As! described in detail hereinafter, a ductor roller 32 is carried for swinging movement between positions respectively engaging receiver roller 30 and a fountain roller 34. It will be appreciated that ink supplied from a reservoir, not shown, to fountain roller 34 is transferred from the fountain roller 34 in succession to the ductor, receiver, idler, oscillator and form rollers and then to the plate cylinder 20 for application, in turn, to blanket cylinder 12 (Figure 1).
As illustrated in Figure 4, attachment 18 is driven from main drive shaft 36 suitably connected to a drive from the printing press 10, such as, e.g. from a gear, not shown, coupled to plate cylinder 20. Main drive shaft 36 carries a driving gear 38 in mesh with a larger gear 40 mounted on an oscillator roller shaft 42. A cam drive shaft 44 is rotatably carried by attachment 18 and carries a gear 46 in mesh with gear 40. Gear 46 also meshes with a gear 48 carried on a shaft 50, carrying receiver roller 30. As explained in detail hereinafter, a drive mechanism is provided for intermittently rotating fountain roller 34 as a result of the driving connection between it and the cam-drive shaft 44. Also, ductor roller 32 is mounted for free rotation in brackets 92 carried by a shaft 94 which is oscillated by cam-drive shaft 44 in a manner explained hereinafter. Consequently, it will be appreciated that the oscillator and receiver rollers 26 and 30 respectively have a continuous rotary motion as a result of the drive from the printer. The oscillator and receiver rollers 26 and 30 respectively drive the idler roller 28 and the form rollers 22 by contact between their respective surfaces. Ductor roller 32 is driven by fountain roller 34 when the two are in contact by the operation of cam-drive shaft 44; ductor roller 32 is driven by receiver roller 30 through the engagement of their respective peripheral surfaces when ductor roller 32 is oscillated to contact receiver roller 30.
In Figures 2 and 5, each attachment 18 is shown divided into three compartments by pairs of inner and outer frame plates 52-i and 52-o, respectively. The centre compartment defined by the inner pair of side plates 52-i houses the rollers 22, 26, 28, 30, 32 and 34 while the two outer compartments defined between each spaced pair of side plates 52-i and 52-o house the gears, cams and other operating mechanisms. Thus, all ink-carrying rollers are isolated from parts requiring lubrication and, conversely, all parts requiring lubrication are isolated from the parts carrying the ink.^*
In Figures 5-7, a three-function cam, generally designated 54, is provided to reciprocate oscillator roller 26 in opposite directions along its axis, to drive ductor roller 32 between positions respectively engaging the fountain and receiver rollers 34 and 30, and to rotate fountain roller 34 intermittently.
Three-function cam 54 comprises a spool or barrel! having inner flange 56 and outer flange 58 defining a groove 60 therebetween. Groove 60 is formed on cam 54 such that it has constant width but wobbles, or shifts axially upon rotation of cam 54. On one side of flange 56 is rigidly carried a gear 62 (see Figure 5). Gear 62 has an axially projecting stub shaft, not shown, rotatably mounting gear 62 and cam 54 for rotation in the frame plate 52-i on the front side of attachment 18. Gear 62 is driven by a gear 64 (Figure 4) mounted on cam-drive shaft 44 and located in the front compartment of the attachment. Consequently, the drive from the printer, particularly the drive from the oscillator to the receiver rollers through the cam drive shaft 44, also rotates three-function cam 54.
To reciprocate oscillator roller 26 in an axial direction, a bracket 66 (Figures 5 and 6) is secured to the outside of front frame plate 52-i. An arm 68 is pivotally secured at one end by pivot pin 70 to bracket 66. The opposite end of arm 68 carries a roller 72 which engages in a groove 74 (Figure 5) of a spool 76 carried on the end of oscillator roller shaft 42. Oscillator roller shaft 42 is axially slidable in bushings 78 carried by the frame plates 52-i.
To impart an oscillatory motion to arm 68 about the pivot pin 70 and consequently oscillate or reciprocate oscillator roller 26 in a direction parallel with its axis, a roller 80 is pivotally carried by arm 68 intermediate its ends. Roller 80 engages in the groove 60 of cam 54. Consquently, as cam 54 is rotated by the drive imparted through gears 38, 40, 46 and 64, shaft 44 and gear 62, roller 80 will follow groove 60 to oscillate arm 68 in a generally horizontal direction about pivot pin 70. Since roller 72 is carried by the free end of arm 68, its engagement in spool 76 causes shaft 42 carrying oscillator roller 26 to reciprocate in an axial direction. Gear 40 and shaft 42 are fixed one to the other and the gear 40 slides axially relative to gears 38 and 46, whereby oscillator roller 26 is continuously rotated as it reciprocates in an axial direction. Gear 40 and shaft 42 may be splined one to the other, if desired, to enable shaft 42 and oscillator roller 26 to reciprocate in an axial direction relative to gear 40 while roller 26 continues to rotate.
Three-function cam 54 also serves to oscillate ductor roller 32 between positions alternately engaging receiver roller 30 and fountain roller 34. As illustrated in Figures 3 and 6, ductor roller 32 is carried by stub shafts 90 received in slots in the upper ends of a pair of axially spaced brackets 92 disposed inside frame plates 52-i. Brackets 92 are carried on a shaft 94, journalled in frame plate 52-i. A plate 95 is suitably clamped or otherwise affixed to shaft 94 and projects forwardly toward the printing press and carries a laterally projecting stub shaft 96. Shaft 96 rigidly carries an arm 97 which also projects toward the press. The distal end of arm 97 carries a roller 98 in engagement with cam surfaces carried by the flange 58 of three-function cam 54·: Arm 97 is biased, as illustrated in Figure 6, for movement in an upward direction by a spring 100 coupled between a pin 101 carried by plate 95 and bracket-66 on frame plate 52-i.
In Figures 6 and 7, the outer flange 58 of three-function cam 54 has an axial projection in the general form of a truncated triangle with the base of the triangle forming the arc of a circle having its axis coincident with the axis of rotation of three-function cam 54. That is, the arcuate cam surface 102 of the axial projection from flange 58, together with the surfaces 104, 106 formed by the sides of the triangle and the flat 108 formed by the truncated top of the triangle, form cam surfaces for roller 98. Thus, roller 98 is biased by spring 100 into following engagement with one of the cam surfaces 102, 104, 106 or 108, depending upon the rotary position of three-function cam 54. Consequently, when roller 98 moves from arcuate cam surface 102 on to one of the surfaces 104 dr 106, depending upon the direction of rotation of the three-function cam 54, the bias of spring 100 causes arm 95 and brackets 92 to pivot in a counterclockwise direction as illustrated in Figure 6 to displace ductor roller 32 away from receiver roller 30 and toward fountain roller 34. When roller 98 engages and tries to follow cam surface 108, ductor roller 32 is pivoted and maintained in engagement with fountain roller 34. When the roller 98 engages surfaces 104 and 106 upon continued rotation of three-function cam 54, plate 95 and brackets 92 are rotated about the axis of'shaft 94 in a clockwise direction as illustrated in Figure 6 to displace ductor roller 32 away from fountain roller 34 and toward receiver roller 30. When roller 98 engages arcuate surface 102 of the three-function cam 54, ductor roller 32 is maintained in engagement with receiver roller 30.
The three-function cam 54 also serves intermittently to rotate fountin roller 34; a circular ratchet wheel 112 is disposed on shaft 110 carrying fountain roller 34. Rotatably carried on shaft 110 is a rocker plate 114, the upper end of which, illustrated in Figure 6, carries a pin 116 on which a pawl 118 is rotatably carried. The tip 120 of pawl 118 is adapted to engage the ratchet teeth 122. Spring 124 connects between a pin 126 carried by pawl 118 and pin 130 carried by rocker plate 114.
A rocker arm or crank 131 is pivotally connected at one end to the lower side of rocker plate 114; its opposite end is pivotally connected to the outer axial face 134 of three-function cam 54 by a pin 136. The rotation of three-function cam 54 thus causes rocker plate 114, through rocker arm 131, to oscillate about shaft 110. When rocker plate 114 pivots in a clockwise direction as illustrated in Figure 6, the tip 120 of pawl 118 rides over teeth 122. When rocker plate 114 pivots about shaft 110 in the opposite direction, tip 120 of pawl 118 engages teeth-122 to drive fountain roller 34 carried by shaft 110 in counterclockwise direction, as shown in Figure 6; however, the direction of rotation is not critical to the operation of the present invention.
To adjust the extent of the angular rotation of fountain roller 34, a pawl shield 140 is rotatably carried on shaft 110 in side-by-side relation with ratchet wheel 112 and in a position to underlie part of the tip 120 of pawl 118. Pawl shield 140 has a circular outer surface 142 which extends for approximately 2700. The remaining outer surface comprises a flat 143, e.g. the chord of a circle. The diameter of surface 142 is slightly larger than the diameter of ratchet wheel 112 such that when part of the tip 120 of pawl 118 bears on the surface 142 of pawl shield 140, pawl 118 is maintained out of engagement with ratchet teeth 122. However, when the shield is rotated such that flat 143 is located below the tip 120 of pawl 118, the bias of spring 124 urges tip 120 into engagement with ratchet teeth 122 and, upon rotation of rocket plate 114, drives fountain roller 34.
The rotary position of shield 140 about shaft 110 is maintained by detent 144 engageable in one of several openings 146 formed in the peripheral surface 142 of pawl shield 140. By rotating pawl shield 140 about the axis of shaft 110, through operation of handle 145, and locking the shield 140 in a selected angular position, the extent of engagement of the tip 120 of pawl 118 with ratchet teeth 122 during angular movement of rocket plate 114 can be adjusted. Consequently, the extent of angular rotation of fountain roller 34 for each rocking movement of plate 114 can be adjusted from zero to a practical maximum of about 45 degrees of arc.
In Figures 8-15, is illustrated a form-roller positioning mechanism for moving the form roller into a selected one of three positions: an "on" position in engagement with both the oscillator roller 26 and plate cylinder 20; an "off" position disengaged from plate cylinder 20 and remaining engaged with oscillator roller 26; and a "lift" position for moving the form roller out of engagement with both the oscillating roller and plate cylinder to enable the rollers to be cleaned.
In Figures 9, 11 and 16, form roller 22 is provided with stub shafts 151, shown in Figure 16 at its opposite ends which are suitably secured to the rotatably carried by the ends of a pair of support arms 152. The opposite end of each support arm 152 is freely rotatable about eccentric shaft 154 which extends through openings 164 formed in the opposite inner frame plates 52-i of the attachment unit. Each support arm 152 is spaced from the associated frame plate 52-i by a collar 158. Collar 158 is secured to eccentric shaft 154 for rotation therewith and carries a lift stop 160 (Figure 11) which projects outwardly of its periphery for engagement with a stop pin '162. Stop pin 162 projects laterally outwardly from support arm 152. As best illustrated in Figure 6, openings 164 in frame plate 52-i are sufficiently large to permit movement of shaft 154 in a direction normal to its axis.
As shown in Figure 9, a stub shaft 166 having a smaller diameter than shaft 154 is suitably secured to each of the opposite ends of shaft 154. Stub shafts 166 are eccentric to the axis of shaft 154. Stub shafts 166 are also rotatably carried in eccentric bushings 168 secured to frame plate 52-o at opposite sides of the attachment unit. That is, the common axis of the bores of bushings 168 is offset from the common axis of the outer surfaces of the bushings. Each bushing mounts a collar 179 inwardly of the outer frame plates 52-o.
At the control or front side of unit 18, each stub shaft 166 is provided with a collar 172 which carries a lever 174. The distal end of lever 174 carries a knob 176 which serves to control a spring-loaded pin 178 which can be inserted into and withdrawn from any of three openings 180, 182, or 184 provided in outer front frame plate 52-o, and which openings correspond to on, off and lift positions of the form roller respectively. Thus, lever 174 can be disposed and maintained in any one of the three positions by operation of knob 176. Movement of lever 174 between the on, off and lift positions caused stub shafts 166 to rotate in the bores of bushings 168. Consequently, eccentric shaft 154 is rotated, and its axis is displaced along an arc having the axis of rotation of stub shafts 166 as its centre.
In Figures 10 and 11, form roller 22 is illustrated in the one position, in engagement against bbth oscillating roller 26 and plate cylinder 20. Knob 176 locates pin 178 in the corresponding opening 180, holding stub shafts 166 and eccentric shaft 154 in a fixed rotary position. The support arms 152, freely rotatable on eccentric shaft 154, enable roller 22 to lie in a position maintained in engagement with the oscillator roller and plate cylinder. A spring-loaded pin 186, carried by the attachment-unit frame along each of its opposite sides, bears on an inclined surface of the corresponding support arm 152 to maintain the form roller 22 in position engaged with both oscillator roller 28 and plate cylinder 20.
To back form roller 22 away from the plate cylinder and consequently move the attachment unit to the off position, lever 174 is rotated, for example in a counterclockwise direction, from its position illustrated in Figure 10 to the position illustrated in Figure 12. Knob 176 is thus operated to locate pin 178 in the second opening 182 in frame plate 52-o. By rotating lever 174, and consequently stub shafts 166, shaft 154 is swung along the arc of a circle having its centre of rotation coincident with the axis of rotation of stub shafts 166. Thus, shaft 154 is displaced in discrete distance along an arcuate path in direction away from plate cylinder 20. As illustrated in Figures 12 and 13, this displacement of eccentric shaft 154 moves the support arms 152 in a like direction, causing form roller 22 to move away from plate cylinder 20 and along the surface of oscillator roller 26'.. Consequently, form roller 22 is spaced from plate cylinder 20 and is slightly elevated with respect thereto as illustrated in Figures 12 and 13. Pins 186 continuously engage support arms 152 to maintain the form roller in engagement with the oscillator roller 26 when the attachment unit is in the off position.
To place the form roller in the lift position, lever 174 is rotated further counterclockwise to the position illustrated in Figure 14, and pin 178 is the lift position. By rotating lever 174 to the lift position, eccentric shaft 154 rotates further about the common axis of stub shafts 166. While rotating, the lift stops 160 carried by collars 158 engage stop pins .162 carried by support arms 152. As shown in Figure 15, further rotation of eccentric shaft 54 thus causes lift stops 160 to lift support arms 152 and form roller 22 therewith. In the lift condition, form roller 22 is spaced from both plate cylinder 20 and oscillator roller 22. As previously noted with reference to Figures 11 and 13, pins 186 are spring-loaded, and retract so that arm 154 may move into their lift positions.
Another feature of the present invention resides in the capability of adjusting the axis of the form roller to ensure parallelism with the axis of plate cylinder 20; or lack thereof, if this condition is desirable. This adjustment feature is best illustrated in Figures 8, 9, 16 and 17. It has been described how bushings 168 have eccentric bores for mounting stub shafts 166. Also, each bushing 168 is rigidly coupled to a surrounding collar 170. As illustrated in Figure 16, collar 170 is rigidly secured to bushing 168 and has a threaded hole for receiving the threaded end of a threaded bushing 190. Threaded bushing 190 is adapted to receive a threaded shaft 192, on the upper end of which is an adjusting knob 194. By rotating knob 194 and threaded shaft 192, threaded bushing 190 is displaced, thus rotating collar 170 and the attached eccentric bushing 168. By rotating bushing 168, and recognizing that stub shafts 166 lie in the eccentric bore of bushings 168, it can be seen that the stub shaft 166 and bracket 152 at each of the opposite sides of the attachment-unit frame may be displaced jointly along the arc of a circle having the axis of bushing 168 as its centre, or separately, such that opposite ends of the form roller 22 are movable substantially toward or away from plate cylinder 20. In this manner, any desired degree of parallelism of the form rollers can be adjusted relative to the axis of the plate cylinder 20.
Those skilled in the art will realise that form roller 22 can be single or multiple; the foregoing description of the positioning and adjustment means is applicable to each form roller which may be used in the apparatus of the present invention.
In summary, the gear 38, through the attached gearing arrangement illustrated in Figure 4, drives both the oscillator and receiver rollers in the same rotational direction, and simultaneously rotates the three-function cam 54 in the opposite direction. By rotating the three-function cam 54 as the oscillator and receiver roller are rotated oscillator roller 26 is simultaneously rotated about its axis and reciprocated in an axial direction. The oscillator roller 26 is reciprocated axially by the engagement of roller 80 between the flanges 56 and 58 of cam 54 which oscillates arm 68 about pivot pin 70. Roller 72 on the end of arm 68 engages spool 76 on shaft 42 to reciprocate oscillator roller 26 in an axial direction.
When roller 98 engages cam surface 102 of three-function cam 54 at a location adjacent cam surface 106, ductor roller 32 engages receiver roller 30. Upon further rotation of three-function cam 54, for example in a counterclockwise direction as illustrated in Figure 6, arm 131 rotates rocker plate 114 in a clockwise direction to retract the tip 120 of pawl 118 along ratchet teeth 122. Upon further rotation of three-function cam 54, roller 98 bears against surface 104 and spring 100 moves bracket 92 mounting ductor roller 32 in a counterclockwise direction as seen in Figure 6 to displace ductor roller 32 into engagement with the fountain roller 34. Continued rotation of cam 54 in a counterclockwise direction brings roller 98 into engagement with cam surface 108 to maintain ductor roller 32 in engagement with fountain roller 34, and causes arm 131 to rotate rocker plate 114 in a counterclockwise direction as illustrated in Figure 6, to index fountain roller 34 in a counterclockwise direction while ductor roller 32 is maintained in engagement against fountain roller 34. Thus, ink received from an ink reservoir, not shown, by fountain roller 34 is transferred to ductor roller 32. Further rotation of cam 54 brings cam surface 106 into engagement with roller 98 causing ductor roller 32 to pivot about axis 94 against the bis of spring 100. This pivoting action displaces ductor roller 32 away from fountain roller 34 into engagement with receiver roller 30. Simultaneously, arm 131 displaces rocker plate 114 in a clockwise direction as illustrated in Figure 6 to withdraw the pawl 118 about ratchet teeth 122. Consequently, the rotary movement of the receiver roller 30 causes ductor roller 32 to rotate with receiver roller 30. With ductor roller 32 held against receiver roller 30 by the cooperation of cam surface 102 and roller 98, ink is transferred from ductor roller 32 to receiver roller 30.
Idler roller 28 is maintained in engagement against both receive roller 30 and oscillator roller 26 by means, such as suitable clamps, screws or springs, not shown, but well known to those skilled in the art. Ink is accordingly transferred from the receiver roller 30 to the idler roller 28 and subsequently to oscillator roller 26. Oscillator roller 26, in turn, applies the ink to form roller 22 for subsequent application to the plate cylinder 20 and blanket cylinder 1₂. ,
The peripheral speeds of the receiver roller and oscillator roller are preferably different one from the other such that a skidding action occurs between the receiver and idler rollers or the idler and oscillator rollers, or both. This skidding ation, in effect, smears and works the ink as it is transferred from one roller to the next, and ultimately provides a uniform distribution of ink on the form rollers as well as delivery of a greater quantity of ink to the form rollers. The ink is thus fed to the oscillator roller in a greater quantity and with a more uniform distribution than would otherwise be the case with simple rolling contact between the surfaces of the idler and receiver rollers or the idler and oscillator rollers or both. The oscillator roller thus delivers sufficient ink to the form roller so that the latter is not starved for ink.
The peripheral speed of the receiver roller is different from and preferably greater than the peripheral speed of the oscillator roller. It has been found that the peripheral speed of the receiver roller should lie within a range of 90% to 120% of the peripheral speed of the oscillator roller, and preferably should be about 107% of the peripheral speed of the oscillator roller. To accomplish this, gear 48 is smaller than gear 40 for the oscillator roller. Thus, the shaft 50 carrying the receiver roller rotates at a higher rate than the shaft 42 , carrying the oscillator roller. While the diameter of the receiver roller 30 is smaller than the diameter of the oscillator roller 26, the decrease in diameter of the receiver roller relative to the oscillator roller is insufficient to compensate for the decreased diameter of the gear 48 for the receiver roller relative to gear 40 for the oscillator roller. Thus, the peripheral speed of the receiver roller 30 exceeds the peripheral speed of the oscillator roller. Since the idler roller 28 lies in constant surface contact with both the receiver and oscillator rollers, a skidding action occurs between one of the receiver or oscillator rollers and the idler roller, or both of the receiver and oscillator rollers and idler roller.
Various methods can be employed to provide the described difference in peripheral speed. For example the idler roller could be driven, rather than idling, and at a different speed from one or both of the receiver or oscillator rollers, to provide a skidding action between the contcting surfaces to achieve the desired results of uniform distribution of ink and distribution of a greater quantity of ink on the form rollers.
In Figure 18, the inking-unit attachment 18 is shown affixed to plate cylinder side frame plate 16. The attachment of the unit 18 is by means of coupling means 200 resting in upper recess 208 of side-plate extension 206. The side-plate extensions 206 are fastened in pairs to the side frame plates' 16 of plate cylinder 20; lower brace 211 of the attachment 18 rests against lower stop means 210 of the side-plate extension 206 to provide a positive spacing. Side-plate extensions 206 are provided with adjustment means 212, shown here as elongated holes, to permit the plate to be affixed to the individual plate cylinder side frame for optimum spacing of adapter gear 214 with respect to plate cylinder gear 216. Fastening means 218, shown here as screws with recessed heads, serve to hold side-plate extensions 206 to side-frame plate 16 through adjustment means 212. Adapter gear 214 runs on drive shaft 36, which is carried between side-plate extension 206.
The adjustment feature of the side-plate extension permit unit 18 to be set at optimum spacing for pressure and alignment of form roller 22, and that the setting will not thereafter change as long as the extensions 206 are not moved. The removal of unit 18 is easily and safely achieved by lifting it in an arc, pivoting on coupling means 200, causing lower brace 211 to swing away from lower stop means 210. As will be noted with reference to Figure 19, this movement of the unit 18 causes gear 40 to move away from driving gear 38, disposed on the opposite end of drive shaft 220 from adapter gear 214. In this manner, the unit can be removed from even a running press, and another one substituted immediately Cover 224, maintained in place to protect the machinery from damage and to protect personnel from injury, is preferably removed before detaching unit 18 from the press.
In Figure 19, the unit 18 is shown from the top, affixed to the press, with form roller 22 running in contact with plate cylinder 20. Adapter gear 214, driven from plate-cylinder gear 216, drives shaft 36 through overload clutch 226 to driving gear 223 in mesh with gear 38. Overload clutch can be coupled to either of the gears 214 or 38, as long as the clutch is interposed between the driving force of the plate-cylinder gear 216 and gear 40 in some fashion" for machinery and personnel safety. As noted above, on the rotation of unit 18 about coupling means 200, driving gear 38 lifts away from gear 40, and the power to the inking unit is disconnected.
While adapter gear 214 and driving gear 38 are shown in Figure 19 as being disposed on opposite ends of shaft 36, both gears could be at the same end of the shaft. Similarly, although the various gears have been illustrated as spur gears, other kinds of gears are generally useful, such as, e.g. bevel, hypoid or worm, depending on the application. Further, shaft 36 could be driven in some other fashion than by direct gear drive from the plate cylinder; a flexible shaft from the axis of the plate cylinder, a chain or belt drive from the plate-cylinder gear, or intermediate gearing from the main drive of the printing press to shaft 220 is within the scope and spirit of this invention.
Another important aspect of the present invention resides in the isolation or compartmentalization of the rollers on the one hand, and the gearing and drive mechanisms on the other. It will be appreciated that the rollers are disposed in the intermediate compartment between inner frame plates 52-i while the drive mechanism is disposed in one or the other of the outer compartments of attachment 18. Thus, ink and solvents used for cleaning the rollers do not intermingle with lubricants used in the drive mechanism and, conversely, the lubricants of the drive mechanism are isolated from the ink and solvents used in the rollers. This feature, in combination with the environmental isolation provided by cover 224, permits singularly clean operation of the unit with respect to the exterior environment, i.e. the area around the printing press, and further serves to maintain the interior of the inking unit free of contamination.

Claims

1. An apparatus for providing ink feed to a printing press, comprising a frame having attachment means thereon;

a fountain roller;

a ductor roller;

a receiver roller;

an idler roller;

an oscillator roller; and

at least one form roller

said rollers being disposed within said frame; said receiver roller and oscillator roller being driven from a drive source, and said fountin roller being intermittently driven from said drive source, said ductor roller, idler roller and form roller being driven frictionally by direct or sequential contact with said receiver roller or oscillator roller, or by direct or sequential contact with a plate cylinder of said printing press.

2. The apparatus of claim 1 wherein said fountain roller is adjustably indexed.

3. The apparatus of claim 1 or claim 2, wherein said' ductor roller intermittently contacts first said fountain roller and then said receiver roller.

4. The apparatus of any of claims 1 to 3, wherein said receiver roller and said oscillator roller operate at different rotational speeds.

5. The apparatus of claim 4, wherein said receiver roller operates at from 50% to 150% of the rotational speed of said oscillator roller.

6. The apparatus of claim 4; wherein said receiver roller operates at from 90% to 120% of the speed of said oscillator roller.

7. The apparatus of claim 4, wherein said receiver roller operates at substantially 107_% of the rotational speed of said oscillator roller.

8. The apparatus of claim 4 or claim 3 when appended to claim 2, wherein said oscillator roller reciprocates axially, the indexing of said fountain roller, intermittent contact of said ductor roller and reciprocation of said oscillator roller being simultaneously driven by a three-function cam.

9. The apparatus of claim 8, wherein said three-function cam has a groove defined by an inner and outer flange, surfaces adjacent said outer flange consisting of an arcuate surface and a plurality of flat surfaces, and a pin affixed normal to said arcuate surface.

10. The apparatus of claim 8, wherein the three-function cam has a pin affixed, said pin being pivotally affixed to one end of a rocker arm, said rocker arm being pivotally affixed at the opposite end thereof to a rocker plate, said rocker plate having affixed thereto a pawl and being pivotally affixed to a shaft, said fountain roller being rotatably disposed on said shaft, said pawl being urged into contact with a circular ratchet wheel, said ratchet wheel having juxtaposed an adjustable pawl shield, said ductor roller being moved into intermittent contact first with said fountain roller and then with said receiver roller by the operation of said three-function-cam, said cam having an arcuate surface and a plurality of flat surfaces, said surfaces having in contact therewith a roller carried on a first arm, said arm being urged into following contact with said surfaces by a spring, said arm being pivotally affixed to a bracket, said bracket disposed to carry said ductor roller, said oscillator roller being reciprocated axially by a second arm having a spool affixed to one end thereof, said spool running in a groove in one end of the axis of said oscillator roller, said second arm having a roller intermediate the ends thereof, said roller following a groove in said three-function cam, said groove being defined by an inner and outer flange, said second arm being pivotally affixed to a bracket at the end opposite said end having a spool affixed, said bracket being rigidly affixed to said frame.

11. A printing press, having an inking-unit attachment in combination with said press, said attachment having a frame having attachment means thereon, a fountain roller, a ductor roller, a receiver roller, an idler roller, an oscillator roller, and at least one form roller, said frame being divided into an innter frame and an outer frame, said rollers being disposed within said inner frame, said press having affixed thereto at least a pair of side-extension plates, said attachment having a cover removably disposed thereon.

12. The printing press of claim 11 wherein said side-extension plates are adjustably affixed to said press.

13. The printing press of claim 11 or claim 12, wherein said side-extension plates have disposed between each of said pair a drive shaft, said drive shaft having an,adapter gear and a driving gear disposed thereon.

14. The printing press of claim 13, yherein said drive shaft has at least one of said adapter gear or driving gear affixed to an overload clutch.

15. The printing press of any of claims 11 to 14, wherein said adapter gear is driven from a plate-cylinder gear on said press.

16. The printing press of any of claims 11 to 15, wherein said attachment is releasably affixed to said press by coupling means adapted to be received in upper-recess means disposed in said side-plate extensions.

17. The printing press of claim 16, wherein said attachment is maintained in position by said coupling means and by lower brace means disposed against lower stop means.

18. The printing press of any of claims 12 to 17, wherein said attachment has positioning means for said form roller.

19. The printing press of claim 18, wherein said positioning means comprises said form roller rotatable on an axis, the shaft of said axis being carried by a support arm, said support arm being rotatable about an eccentric shaft affixed to a collar and maintainable in a given " position by a lever affixed to said collar, said lever having a spring-loaded pin disposed therein and positionable in spaced openings, said spring-loaded pin operable by a knob.

20. The printing press of claim 19, wherein said spaced openings comprise three openings.

21. The printing press of any of claims 11 to 20, including means carried by said frame for moving said form roller between a position in engagement with said second roller and a position spaced therefrom.

22. The printing press of any of claims 11 to 21, including an arm rotatably carrying said form roller, a shaft carried by said frame mounting said arm, and means carried by said frame mounting said shaft for rotation about an axis offset from the axis of said shaft for displacing said form roller in a direction normal to its axis.

23. The printing press of claim 22, wherein said form roller lies in engagement with said second roller and the plate cylinder to transfer ink from said second roller to the plate cylinder, said arm being freely rotatably carried by said shaft, means carried by said shaft and cooperable with said arm for displacing said form roller in a direction normal to its axis and away from engagement with the plate cylinder and said second roller.

24. Apparatus for supplying ink to a printing press comprising a frame including a pair each of inner and outer frame plates spaced one from the other and defining a pair of outer compartments and an intermediate compartment therebetween, a fountain roller carried by said frame and disposed in said intermediate compartment, said fountain roller being carried by said frame for rotary indexing movement, a receiver roller carried by said frame and disposed in said intermediate compartment, a ductor roller carried by said frame and disposed in said intermediate compartment, said ductor roller being carried by said frame for rocking movement between positions engaging said fountain roller and said receiver roller respectively for transferring ink from said fountain roller to said receiver roller, an oscillator roller carried by said frame and disposed in said intermediate compartment, said oscillator roller being carried by said frame for reciprocating movement in the direction of its axis, an idler roller carried by said frame and disposed in said intermediate compartment in surface engagement with said receiver roller and said oscillator roller for transferring ink from said receiver roller to said oscillator roller, means carried by said frame in one of said outer compartments for driving one of said receiver roller and said oscillator roller, and means coupled to said drive means and carried by said frame in the other of said compartments for indexing said fountain roller, rocking said ductor roller, and reciprocating said oscillator roller.

25. The apparatus of claim 24, wherein said drive means includes means for rotating one of said receiver roller and said oscillator roller at a peripheral speed different from the peripheral speed of the other of said receiver roller and said oscillator roller to provide a skidding action between the contact surfaces of said idler roller and one of said receiver roller and said oscillator roller.

26. The apparatus of claim 24, wherein at least one form roller is disposed within said frame.

27. The apparatus of claim 26 wherein adjustment means is provided for said form roller.

28. The apparatus of claim 27 wherein said adjustment means comprises eccentric means for mounting said form roller, and means for effecting the movement of said eccentric means.