US3698313A

US3698313A - Means for oscillating and silencing a ductor roller in a printing press

Info

Publication number: US3698313A
Application number: US49587A
Authority: US
Inventors: Leonard I Tafel
Original assignee: North American Rockwell Corp
Current assignee: Boeing North American Inc
Priority date: 1970-06-25
Filing date: 1970-06-25
Publication date: 1972-10-17
Anticipated expiration: 1989-10-17

Abstract

A mechanism for selectively oscillating the ductor roller of a printing press wherein a barrel cam, mounted on a drive shaft, has a first cam track which is ramped to provide ''''throw'''' for oscillation of the ductor roller and a second track having zero ''''throw'''' for maintaining the ductor roller in constant contact with the ink drum. In the preferred embodiment a ductor rollersupporting shaft, mounted perpendicularly to the drive shaft, carries the ductor roller eccentrically mounted for lateral swinging movement and also carries a cam follower eccentrically mounted for engagement with the barrel cam member. An actuator axially shifts the ductor roller-supporting shaft for selective engagement of the first and second cam tracks.

Description

United States Patent Tafel 1541 MEANS FOR OSCILLATING AND SILENCING A DUCTOR ROLLER IN A PRINTING PRESS [72] Inventor: Leonard I. Tafel, L a Orange, 111. [73] Assignee: North American Rockwell Corporation, Pittsburgh, Pa.

[22] Filed: June 25,1970

[21] App]. No,.: 49,587

[52] US. Cl ..101/350, l01/D1G. 6 [51] Int. Cl. ..B4lf 31/06 [58] Field of Search ..101/349, 350, 351, 352, 148,

101/DIG. 6, 335, 202, 205, 206, 210, 356,,

[56] References Cited UNITED STATES PATENTS 2,467,199 4/1949 Faeber ..101/348 2,462,032 2/1949 Wolf ..101/352 X 3,382,963 5/1968 Cralle, Jr. et al. ..197/16 2,330,359 9/1943 Hill ..101/350 2,276,525 3/1942 Trotter ..,101/350 1,173,488 2/1916 Cooper ..101/350 2,660,088 11/1953 Serra ..74/54 X 2,622,521 12/1952 Larsen ..101/148 2,177,253 10/1939 ,Harless ..101/350 1451 Oct. 17,1972

3,238,797 3/1966 Coughren ..74/567 x 3,064,564 1l/1962 Lindemann ..101/351 2,474,160 6/1949 Peyrebrune 101/348 2,711,935 6/1955 Miles ..101/349 ux FOREIGN PATENTS OR APPLICATIONS 248,154 3/1926 Italy ..74/54 Primary ExaminerR. E. Pulfrey Assistant Examiner-R. E. Suter Attorney-John R. Bronaugh et a1.

[ 5 7 ABSTRACT engagement with the barrel cam member. An actuator axially shifts the ductor roller-supporting shaft for selective engagement of the first and second cam tracks.

3 Claims, 8 Drawing Figures PATENTEDnmH 1972 3.698.313

zza/mea 1. 774564 MEANS FOR OSCILLATING AND SILENCING A DUCTOR ROLLER IN A PRINTING PRESS Modern commercial offset printing presses must operate at high speed and with as little noise and vibration as practicable. Among the parts which must be moved back and forth is the ductor roller, which oscillates between a first position in which the roller contacts the fountain roller of the printing press and a second position in which the ductor roller contacts the adjacent ink drum for conveying incremental charges of ink to the latter. 3

In the past, various linkage arrangements have been employed to oscillate the ductor roller, but these have been somewhat complex and bulky and have been poorly suited to turning off, or silencing the ductor movement. Several such arrangements have used loosely mounted keys or other parts which, in operation, slap or rattle, and which are sources of vibration and wear.

It is therefore an object of this invention to provide a drive arrangement for the ductor roller of a printing press which is quiet in operation and which operates without the wear and adjustment problems engendered by loosely mounted keys or other elements.

It is another object to provide a drive arrangement for a ductor roller which has provision for easy shifting into a disengaged or neutral condition, for example, in constant contact with the ink drum, in which the ductor is stationary or silenced.

It is still another object to provide a ductor roller drive mechanism which is simple and compact in design, inherently durable, and capable of operating for long periods without care or maintenance.

It is yet another object of the invention to provide a drive for a ductor roller which oscillates between a fountain roller and an ink drums and whichpermits ad justment, under running conditions, of the ductor-todrum pressure. v

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in

which:

FIG. 1 is a vertical view in partial section showing the drive end of a printing pressunit;

FIG. 2 is a partial section taken along line 22 in FIG. 1;

FIG. 2a is a fragmentary section taken along line 2a-2a in FIG. 2;

FIG. 2b is a section taken along line 2b- -2b in FIG. 20;

FIG. 3 is a partial section taken along line 3-3 in FIG. 2; and

FIG. 4 is a partial section taken along line 4-4 in FIG. 3.

FIG. 5 is a fragmentary view showing a modified form of the invention looking along line 55 in FIG. 20.

FIG. 5a is a fragmentary view of the actuator assembly used in conjunction with the structure of FIG. 5 to secure running pressure adjustment.

While the invention will be described in connection with a preferred embodiment, it will be understood that 1 do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternative uses, modifications and equivalents as may be includedv within the spirit and scope of the invention as defined by the appended claims.

Turning first to FIG. 1, there is shown a typical offset printing press unit '10. A web 11 of material to be printed, normally paper, is passed. to the unit 10 from a neighboring unit 12 and then toa unit 13. Blanket cylinders 14 and 15, printing on opposite sides of the web, cooperate with plate cylinders 16 and 17, respectively. The plate cylinders 16 and 17 are inked and moistened by ink and water systems including intermediate rollers 19. Attention may be focused on the ink system 20 shown in FIG. 3. In such system, ink 21 is supplied from an inking fountain 22 by a fountain roller 23 the ink then being transported by a ductor roller 25, in accordance with the invention, to an ink drum 27. From the ink drum the ink film is transferred to a roller 28 which conveys it to the intermediate rollers 19 for transfer to the surface of the plate cylinder.

To supply motive power to drive the various cylinders and other parts of the press in synchronism, a horizontal drive shaft 30 shown in FIG. 1 is provided which mechanically interconnects the adjacent printing units. To operate the mechanisms within the unit 10, a subdrive is provided including a vertical shaft 31. The horizontal shaft 30 is, as shown, coupled to the cylinder 14 by a pair of bevelgears 30a, with motion being transmitted to the other cylinders by the usual spur gears. The vertical shaft 31 is driven at a reduced speed by worm gearing 32 coupled to the cylinder spur gears.

In accordance with the present invention, a barrel cam is provided on the drive shaft 31 having cam surfaces which are engaged by a cam follower which serves to rock a shaft on which the ductor roller is eccentrically supported, the cam having adjacent cam tracks in the form of a ramped surface and adjacent flat surface and the cam follower having means for shifting from one track to the other for respectively oscillating the ductor roller and for holding it in a stationary position against the fountain roller notwithstanding continuous rotation of the cam.

In the present embodiment shown in FIGS. 2-5, the barrel cam 33 is formed of two generally disc-shaped members 33a, 33b'mounted upon the drive shaft 31 and having mating sets of cam surfaces for receiving a cam follower between them. Turning attention to the cam surfaces onthe member 33b, the first of the adjacent tracksis ramped, having a low sector 35 and a high sector 36, the two sectors being joined by ramps 37 to provide a certain amount of throw. The second cam track on the member 33b, which is indicated at 38. (FIG. 2a), is planar or uh-ramped and is oriented perpendicularly to the drive shaft 31 to provide zero throw.

The cam surfaces on the disc shaped member 330, which are correspondingly numbered herein, are precisely complimentary to thecam surfaces on the member 33b. These complimentary cam surfaces insure positive displacement of the follower in both directions without lost motion.

For actuation by the rotating barrel cam 33, a cam follower arm 40 is provided. As here illustrated in FIG. 2a, the cam follower arm has, mounted at its end, a follower in the form of rotatable follower wheel 41 which is sandwiched between the cam members 33a, 33b. The cam follower, arm is keyed to a ductor roller-supporting shaft 46. The shaft46 has brackets 47 secured, by keying, to its ends for rotatably mounting the axle, indicated at 48, of the ductor roller 25 in eccentric position so that oscillatory, or rocking, motion is imparted to the ductor roller in response to oscillatory motion of the cam follower arm. In operation, when the cam follower roller 41 contacts the first, or ramped, cam track 35-37 of the rotating barrel cam 33, oscillatory motion of limited amplitude is produced in the shaft 46, one oscillatory cycle for each revolution of the drive shaft 31. Alternatively, when the cam follower roller 41 engages the adjacent, planar, cam track 38, there is no throw of the cam follower or any rocking of shaft 46, so that the ductor roller is held stationary against the fountain roller. The transition between the two conditions occurs silently and smoothly with no loss of contact at the cam follower.

For adjusting the position of the ductor roller with respect to its supporting brackets, each of the brackets 47 has an adjusting mechanism 49. The adjusting mechanism includes collars 50 (FIG. 4) which engage the shaft and which are engaged by adjusting screws 51 and 52 for relative positioning. If desired, by adjusting one collar relative to the other, the ductor roller 25 may be slightly skewed.

Further in accordance with the invention, shifter means are provided for shifting the cam follower arm 40 between the first track or pair of cam surfaces 35-37 and the second track or pair of cam surfaces 38, for initiating silencing ductor roller oscillatory motion. In the present embodiment, the shifter means 54 includes a fluid actuator 56 mounted coaxially at the end of the ductor roller-supporting shaft 46 having a piston 57 movable between fixed stops, which may be provided in the actuator itself, to define the range of axial shifting, the piston being coupled to the end of the shaft 46 by a captive bearing 58 as shown in FIGS. 2a and 4. Suitable valves (not shown) serve to apply pressure fluid alternatively to the opposite ends of the actuator.

It is one of the further features of the present construction that the same drive shaft 31 upon which the barrel cam is mounted serves to rotate an adjacent Wobbler cam having a cam follower, which is coupled through a one-way clutch, to steppingly index the fountain roller 23 which serves as a source of ink for the ductor roller 25. Thus, referring to FIGS. 1 and 2, the shaft 31 serves to rotate a Wobbler cam 60 which is located immediately adjacent the barrel cam 33 and which has a cam follower in the form of a yoke 61 having inwardly'directed cam follower rollers 62. The yoke 61 is coaxial with, and coupled to, a one-way clutch 63 of the simple ratchet type having its output element 64 connected to the fountain roller 23. Thus, as the shaft 31 rotates, the yoke 61 oscillates about an axis at right angles thereto. Such oscillatory movement, through a limited angle, fed to the one-way clutch, causes the fountain roller 23 to be indexed forwardly in small increments thereby presenting an ever-fresh film of ink to the ductor roller 25 which periodically engages it. It should be noted that since both of the mechanisms are coupled to the same drive shaft, the oscillation of the ductor roller will always take place precisely in synchronism with the indexing advancement of the fountain roller so that precisely the same amount of ink will be picked up by the ductor roller during each oscillating cycle. While ink is thus fed to the drum 27 in successive increments, the plurality of rollers in the ink feed system, a portion of which are vibrated endwise,

insures that the ink will be in the form of a thin, even film by the time that it is applied to the plate cylinder.

It will be apparent in any event that I have provided an oscillating drive for a ductor roller which eminently meets the stated requirements. Operation is smooth and free of vibration and all of the components are tight without the freedom and play which causes noise, wear and vibration in conventional mechanisms intended for this purpose. It is an easy matter, simply by shifting the shaft 46 endwise, to switch the cam follower from the active cam' surfaces to the planar, or passive, cam surfaces to turn off the movement of the ductor roller with the drive shaft 31 still in motion.

In the embodiment of the invention discussed above, the amount of throw of the cam and hence the angular movement of the supporting shaft 46 is fixed. When the press is at rest, the amount of pressure exerted by the ductor roller against the drum 27 may be adjusted by the adjusting screws 51. However, in accordance with one of the aspects of the present invention, the mechanism described above may, by slight modification, be made to provide adjustment of pressure between the ductor roller during interval that the latter are in contact, with the press and ductor roller in motion. This is accomplished by modifying the low portion 35 of the outer cam track so that it is no longer flat i.e., perpendicular to the cam axis, but so that it occupies a conical locus. In addition, means are provided for adjusting the position of the cam follower roller thereby to determine the level that the cam follower rides on the conical surface which, in turn, permits a running adjustment in the amount of throw of the ductor roller and hence the amount of pressure which is exerted by the resiliently covered ductor roller against the ink drum during the interval that the two are in contact with one another. Thus, referring to FIG. 5, where corresponding numerals with additional subscripts a denote corresponding parts, the lower sector surface 35a, which is engaged by the cam follower roller 41a, occupies a conical locus having an external angle a with respect to a reference plane perpendicular to the cam axis. A corresponding surface 35a is formed on the opposite cam disc- In the earlier embodiment, an angled ramp 37 is provided between the lower sector surface 35 and the upper sector surface 36. Conveniently, in the embodiment shown in FIG. 5, such ramp may be eliminated and the conical locus lower sector surface 35a, conically angled, may merge with'the upper sector surface which in profile is an extension of illustrated inner cam track surface 38a. It will be apparent that by adjusting the cam follower roller 41a from the dot-dash position to the full line position (FIG. 5), thus causing the cam follower to ride at a lower" level, the ductor roller will be moved toward the ink drum 27 in additional amount to produce a wider flat" during the time that the ductor roller is in engagement with the ink drum and thereby changing the amount of ink which is effectively fed to the ink drum during each ductor stroke.

For the purpose of adjusting the level at which the cam follower roller 41a rides upon the conical surface 35a, means are provided for slightly shifting the range of movement of the actuator 56. As shown in FIG. 5a, the actuator 56, instead of being fixed to the press may have provision for slight endwise movement. In one embodiment the bushings 70, upon which the actuator is mounted, may be telescopically received in openings 71 bored into the press frame, but with the actuator assembly being held in extended position by means of stiff springs 72. To establish the position of the actuator an adjusting screw 73 is threaded into a stationary nut 74, with the position of the actuator being indicated on a suitable scale 75. While it is true that bodily shifting the actuator changes both of the endwise limits of movement of the supporting shaft 46, the throw of the cam follower, by reason of the flatness of the surface 36, is increased only in one direction, the direction of the ink drum, for increasing the pressure against the latter. It will be apparent that the screw 73 may be adjusted with the press and ductor in normal operation so that the results of making a change may be immediately observed.

The term barrel cam used herein is intended to refer to a cam which is rotatably driven and which has a pair of cam faces facing axially and which cooperate with one another to drive a cam follower without any play or lost motion. While the pair of cam surfaces face mutually inwardly in the barrel cam assembly 33 disclosed herein, it will be apparent to one skilled in the art that the invention is not limited thereto and, if desired, a cam could be substituted in which the axially facing cam surfaces face mutually outwardly, in which case the cam follower would be in the form of a yoke embracing the rotated cam and having portions in simultaneous engagement with both the cam surfaces. The term ramped refers to cam surfaces which are smoothly stepped or angled to achieve predetermined throw of the associated cam follower. The term keyed denotes a rigid connection. The term substantially flat or substantially planar as applied to the surface of the second cam track, refers to a degree of flatness which will prevent transfer of ink by the ductor in successive contact with the fountain roller and ink drum. The terms low and high as applied to the cam levels are relative terms usedfor convenience in defining the throw.

l claim as my invention:

1. In a printing press inking system of the type having a ductor roller oscillated between a fountain roller and an adjacent ink drum, the combination comprising: a frame, a ductor roller, a ductor roller-supporting shaft rockably supported in the frame parallel to the ductor roller and having a pair of brackets spaced from one another and keyed to the shaft for supporting the ductor roller in eccentric position on the supporting shaft, a drive shaft journalled in the frame and extending at right angles to the roller-supporting shaft, a cam on the drive shaft, a cam follower arm keyed to the roller-supporting shaft, the cam follower arm having a cam follower engaging the cam, the cam having a ramped surface consisting of a low sector and a high sector so that upon rotation of the drive shaft the roller supporting shaft is oscillated thereby oscillating the ductor roller through limited lateral movement for alternate contact the drive shaft, and means for adjusting the radial position of the cam follower relative to the cam axis so that the cam follower engages the conical locus at a desired level thereby to adjust the pressure exerted by the ductor roller against the ink drum during the time the two are in contact with one another.

2. In a printing press inking system of the type having a ductor roller oscillated between a fountain roller and an adjacent ink drum, the combination comprising: a frame, a ductor roller, a ductor roller-supporting shaft rockably supported in the frame parallel to the ductor roller and having a pair of brackets spaced from one another and keyed to the roller supporting shaft for supporting the ductor roller in eccentric position on the supporting shaft, a drive shaft journalled in the frame and extending at right angles to the roller-supporting shaft, a cam on the drive shaft, a cam follower arm keyed to the roller-supporting shaft, the cam follower arm having a cam follower engaging the cam along a radius of the cam, the cam having a ramped surface ineluding a first sector and a second sector so formed that upon rotation of the drive shaft the roller supporting shaft is oscillated thereby oscillating the ductor roller through limited lateral movement so that it alternately contacts the fountain roller and the adjacent drum for conveying ink in increments to the latter when the cam follower engages the ramped cam surface, the first sector lying in a shallow conical locus about an axis defined by the drive shaft, the cam having a substantially planar surface adjacent the ramped surface facing in the same direction and merging therewith, means for axially shifting the roller supporting shaft between first and second positions thereby to shift the cam follower from the ramped surface to the planar surface for eliminating the oscillatory movement of the ductor roller, and means for adjusting the position of the axially shifting means so that the cam follower engages the conical locus at a desired level thereby to adjust the pressure exerted by the ductor roller against the ink drum during the time the two are in contact with one another.

3. In a printing press inking system of the type having a ductor roller oscillated between a fountain roller and an adjacent ink drum, the combination comprising: a frame, a ductor roller supporting shaft rockably supported in the frame, means for mounting the ductor roller in an eccentric position on the supporting shaft, a drive shaft journalled in the frame, a cam carried by the drive shaft, a cam follower arm on the supporting shaft carrying a cam follower which engages the cam, said cam having a ramped surface for imparting throw to the cam follower for oscillation of the ductor roller and having an adjacent non-ramped surface for eliminating oscillatory movement of the ductor roller, means for shifting the cam follower between the ramped and nonramped surfaces, the ramped surfiace having a portion in the locus of a cone whose axis is located on the drive shaft, and means for adjusting the position of the cam follower along the height of the cone thereby to adjust the pressure which exists between the ductor roller and the ink drum when the two are in contact with one another.

Claims

1. In a printing press inking system of the type having a ductor roller oscillated between a fountain roller and an adjacent ink drum, the combination comprising: a frame, a ductor roller, a ductor roller-supporting shaft rockably supported in the frame parallel to the ductor roller and having a pair of brackets spaced from one another and keyed to the shaft for supporting the ductor roller in eccentric position on the supporting shaft, a drive shaft journalled in the frame and extending at right angles to the roller-supporting shaft, a cam on the drive shaft, a cam follower arm keyed to the roller-supporting shaft, the cam follower arm having a cam follower engaging the cam, the cam having a ramped surface consisting of a low sector and a high sector so that upon rotation of the drive shaft the roller supporting shaft is oscillated thereby oscillating the ductor roller through limited lateral movement for alternate contact with the fountain roller and the adjacent drum for conveying ink in increments to the latter when the cam follower engages the ramped cam surface, the low sector lying in a shallow conical locus about an axis defined by the drive shaft, and means for adjusting the radial position of the cam follower relative to the cam axis so that the cam follower engages the conical locus at a desired level thereby to adjust the pressure exerted by the ductor roller against the ink drum during the time the two are in contact with one another.

2. In a printing press inking system of the type having a ductor roller oscillated between a fountain roller and an adjacent ink drum, the combination comprising: a frame, a ductor roller, a ductor roller-supporting shaft rockably supported in the frame parallel to the ductor roller and having a pair of brackets spaced from one another and keyed to the roller supporting shaft for supporting the ductor roller in eccentric position on the supporting shaft, a drive shaft journalled in the frame and extending at right angles to the roller-supporting shaft, a cam on the drive shaft, a cam follower arm keyed to the roller-supporting shaft, the cam follower arm having a cam follower engaging the cam along a radius of the cam, the cam having a ramped surface including a first sector and a second sector so formed that upon rotation of the drive shaft the roller supporting shaft is osciLlated thereby oscillating the ductor roller through limited lateral movement so that it alternately contacts the fountain roller and the adjacent drum for conveying ink in increments to the latter when the cam follower engages the ramped cam surface, the first sector lying in a shallow conical locus about an axis defined by the drive shaft, the cam having a substantially planar surface adjacent the ramped surface facing in the same direction and merging therewith, means for axially shifting the roller supporting shaft between first and second positions thereby to shift the cam follower from the ramped surface to the planar surface for eliminating the oscillatory movement of the ductor roller, and means for adjusting the position of the axially shifting means so that the cam follower engages the conical locus at a desired level thereby to adjust the pressure exerted by the ductor roller against the ink drum during the time the two are in contact with one another.

3. In a printing press inking system of the type having a ductor roller oscillated between a fountain roller and an adjacent ink drum, the combination comprising: a frame, a ductor roller supporting shaft rockably supported in the frame, means for mounting the ductor roller in an eccentric position on the supporting shaft, a drive shaft journalled in the frame, a cam carried by the drive shaft, a cam follower arm on the supporting shaft carrying a cam follower which engages the cam, said cam having a ramped surface for imparting throw to the cam follower for oscillation of the ductor roller and having an adjacent non-ramped surface for eliminating oscillatory movement of the ductor roller, means for shifting the cam follower between the ramped and non-ramped surfaces, the ramped surface having a portion in the locus of a cone whose axis is located on the drive shaft, and means for adjusting the position of the cam follower along the height of the cone thereby to adjust the pressure which exists between the ductor roller and the ink drum when the two are in contact with one another.