US3641933A

US3641933A - Registry mechanism for printing units

Info

Publication number: US3641933A
Application number: US44246A
Authority: US
Inventors: Leonard I Tafel
Original assignee: North American Rockwell Corp
Current assignee: Boeing North American Inc
Priority date: 1970-06-08
Filing date: 1970-06-08
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15

Abstract

A coupling mechanism between a printing unit and a drive shaft which powers a number of adjacent printing units acting upon the same web of paper having a drive gear adjustable in phase position. To obtain such adjustment, first and second sleeves are provided on the shaft having meshing helical splines. The first sleeve slidably keyed to the shaft, has a yoke for adjusting its axial position, thereby to change the degree of engagement of the helical splines and the phase position of the drive gear. The yoke is in the form of a threaded collar encircling the first sleeve and axially movable by means of a captive nut. The second sleeve has a shiftable yoke which positions the drive gear in meshing engagement with the driven gear and which permits retraction of the drive gear for declutching and timing purposes.

Description

United States Patent Tafel Feb. 15, 1972 [54] REGISTRY MECHANISM FOR 2,418,555 4/1947 Kirsten ..74/417 X PRINTING UNITS FOREIGN PATENTS 0R APPLICATIONS [72] Lma'd La Grange 537,291 10/1931 Germany ..101/248 [73] Assignee: North American Rockwell Corporation, 151,391 8/ 1955 Sweden 101/248 Pittsburgh, Pa. Primary Examiner.l. Reed Fisher [22] mm Attorney-Wolfe, Hubbard, Leydig, v01: & Osann, Ltd.

[21] Appl. N0.: 44,246

ABSTRACT 521 US. Cl ..10l/18l, 101/248 A p i mechanism between p g d a drive 511 1111.01. .3411 13/14 Shaft whlch Powers a number of i t p s y es 1581 Held of Search 101/248, 181, 183, 180, 174, "P the i web of Pap having a dnve gear adjustable m 101/177, 178, 136, 138, 139, 140, 182, 184, 216, phase position. To obtain such ad ustment, first and second 29; 74/395 400, 402 sleeves are provided on the shaft having meshing helical splines. The first sleeve slidably keyed to the shaft, has a yoke 56] References Cited for adjusting its axial position, thereby to change the degree of engagement of the helical splines and the phase position of the UNITED STATES PATENTS drive gear. The yoke is in the form of a threaded collar encircling the first sleeve and axially movable by means of a captive 2,893,310 7/1959 Johnson ..101/248 X mm The second Sleeve has a shiftable yoke which positions 2539068 1/195 1 Funk "101/248 the drive gear in meshing engagement with the driven gear and S which permits retraction of the drive gear for declutching and angs on e timin u ses. 1,850,800 3/1932 Langston et al. .....101/24s gp rpo 2,755,686 7/1956 Bade ..74/417 X 5 Claims, 3 Drawing Figures PATENTEI] FEB 15 I972 SHEET 1 OF 3 REGISTRY MECHANISM FOR PRINTING UNITS In printing presses, for example, presses of the perfecting lithographic type, intended for simultaneously printing on opposite sides of a continuous web, are made up of a plurality of printing units arranged side by side for acting in succession on the web and all driven by a single longitudinal drive shaft. In order to insure proper registration between successive printed impressions, particularly in multicolor printing, it is essential to have the printing cylinders perfectly phased with the printed impressions on the web. Approximate phasing can be achieved by declutching, that is, by unmeshing the gears between the drive shaft and the cylinders and remeshing them in approximate phase position. However, for procuring precise register and for making minor running adjustments from time to time, it is necessary to provide means which permit' a fine continuous and precise adjustment in phasing between the shaft and the gears which are driven by the shaft.

it is an object of the present invention to provide improved means for adjusting the phase position of the drive gearing for a printing unit with respect to the drive shaft which powers a number of cooperating press units all acting upon a single web of paper. It is a more specific object to provide an adjustable coupling of novel construction between the drive shaft and a drive gear thereon which permits gross changes in phase position by unmeshing the gears and remeshing them in a new position as well as continuous fine adjustment in phase position as required, for example, where impressions of different color must be overprinted in precise register with one another.

It is another object of the present invention to provide a coupling between a drive shaft and the cylinders of a printing unit which permits fine changes in registry to be made, and maintained, without necessity for stopping the press.

It is another object of invention to provide a phase-adjusting coupling for a printing unit which includes a pair of sleeves having a helical splined connection between them and in which the degree of spline engagement determines the relative phasing between the drive gear and the shaft upon which it is mounted. It is a related object to provide a coupling in which the sleeve which transmits the output torque is subject to end thrusts which cancel one another, permitting such sleeve to be maintained in position with relatively light mechanism and utilizing only light control forces.

It is another object of the present invention to provide a register adjusting arrangement including a positioned sleeve keyed to the drive shaft under the control of a positioning yoke of simple collar construction which is nonrotatable and which is threaded for movement by a nut for effecting extremely small changes in sleeve position in one direction or the other.

It is more specifically an object of invention to provide a phase adjusting mechanism in which the same helical splines which bring about small changes in phase are utilized in the declutching movement necessary for freeing the gears to achieve gross changes in phase position.

It is a general object of the invention to provide a phase adjusting arrangement for units of a printing press which is of simple and economical construction, which may be easily operated with the drive shaft and press cylinders in motion, which has a minimum number of backlash points and minimum windup, and which is capable of holding the adjustment for long press runs without any care or attention on the part of the operator.

Other objects and advantages of the invention will become apparent upon reading the attached detailed description in which:

FIG. 1 is an elevational view, in partial section, showing a press unit having a phase-adjustment coupling constructed in accordance with the present invention and showing portions of the adjacent press units.

FIG. 2 is a vertical enlarged section taken through the phase-adjusting coupling in FIG. 1.

FIG. 3 is a simplified transverse section looking along line 3-3 in FIG. 2.

FIG. 4 is a fragmentary view, enlarged as compared to FIG. 1, and showing the clutch control member.

FIG. 5 is an enlarged perspective view of the first adjustable sleeve which forms a part of the assembly.

While the invention has been described in connection with a preferred embodiment, it will be understood that I do not intend to be limited to the particular embodiment shown but intend, on the contrary, to cover the various alternative and equivalent constructions included within the spirit and scope of the appended claims.

Turning now to FIG. 1, there is disclosed a printing unit 10 forming a part of a perfecting lithographic press and with adjacent, similar units ll, 12 all of which simultaneously print on opposite sides ofa paper web 13. The printing unit is of boxy construction having end frames 21, 22 in which the cylinders and rollers are joumaled, and

side frames

23, 24. For printing the upper surface of web 13 a plate cylinder 31 applies an inked impression to a blanket cylinder 32, with the ink being fed to the plate cylinder by an ink system 33, and with water being furnished by a dampening system 34. Similarly, for printing the underside of the web 13, a plate cylinder 35 applies an inked impression upon a blanket cylinder 36, the ink and water systems being indicated at 37, 38, respectively. The blanket cylinders 32, 36, arranged in opposition, act as impression cylinders for one another. The

cylinders

31, 32 and 35, 36 will be understood to be geared together by the usual helical gears (not shown), the blanket cylinder 32 being powered by a driven gear, in the form of a spiral bevel-type gear 39.

As is usual in printing presses employing multiple units, a single horizontal drive shaft 40 is drivingly coupled to all of the units. Conveniently, the drive shaft is broken into sections by couplings 41, 42, a typical section being joumaled in bearings 43, 44.

In accordance with the present invention a first, or outer, sleeve and a second, or inner, sleeve are provided on the drive shaft 40, the sleeves having interengaging helical splines, with the first sleeve being slidably keyed to the drive shaft with provision with endwise adjustment and with the second sleeve carrying a helical bevel-type gear having means for holding the same in mesh with the driven spiral gear 39 connected to the press cylinders. In the present embodiment the first sleeve, indicated at 50, is keyed to the shaft by a key 51 which is slidably engaged by the walls of an axial groove 52 formed inside of the sleeve (see FIG. 4). At its right-hand end, the sleeve has a set of splines 53, which are helically formed. Surrounding the sleeve 50 is a second sleeve 55 having a set of internal helically formed splines 56. The sleeve 55 is secured, by a ring of screws 57, to a collar 58 which is integral with a helical bevel-type drive gear 59 which is snugly but freely slidable with respect to the outer surface of the shaft 40.

In FIG. 2, the drive gear 59 is shown in two separate posi tions, in a first or dot-dash position in which the gear is in mesh with the driven gear 39, and a second or retracted position in which the gear 59 is retracted out of mesh with the driven gear 39. For the moment, it will be assumed that the drive gear 59 occupies its meshed position, and mention will be made in due course of the means for holding the drive gear in meshed position.

Further in accordance with the invention, a positioning yoke is provided for engaging the sleeve 50 for adjusting the axial position of the sleeve with respect to the shaft and hence the degree of engagement, under running conditions, of the helical splines 53, 56, the yoke being in the form of a nonrotatable hub or collar threaded for axial movement, in one direction or the other, by a captive nut. Thus, referring to FIG. 2, the yoke indicated at 60 is slidably mounted in a cylindrical bushing 61 having a smooth cylindrical inner surface 62, and a mounting flange 63 which is secured to the wall 23 of the press by a circle of mounting screws 64. In order to prevent rotation of the yoke 60, a key is provided in the form of a pin 65 which penetrates an opening 66 in the bushing to extend into an axial groove 67 formed in the outer wall of the member 60.

To provide coupling between the yoke 60 and sleeve 50, a bidirectional thrust bearing is provided in the form of a pair of opposed roller bearings 71, 72. The first bearing 71 has an outer race which is seated in a groove formed in the yoke and an inner race which abuts against the presented ends of the splines 53 on the sleeve. The opposed bearing 72 has an outer race which is seated in the yoke and an inner race which is clamped in place by a nut 73 engaging a thread 74 formed on the left-hand end of the sleeve. The clamping nut serves to remove any endwise play between the yoke and the sleeve, while the bearings accommodate the relative rotation.

For the purpose of adjusting the yoke 60 endwise, the yoke is provided, at its left-hand end, with a screw thread 80 which is engaged by a captive nut 81. The nut, which is of circular shape, is held captive by a flanged ring 82 which is secured to the nut by a series of machine screws 83. The flange on the ring, indicated at 84, forms an internal annular groove which receives and mates with, a flange 85 integrally formed on the bushing 63. For the purpose of rotating the circular nut 81 it carries, about its periphery, gear 86 which meshes with an adjusting pinion 87 having a shaft 88 which is coupled to some convenient setting means.

For the purpose of preventing entry of foreign matter along the shaft and into the bearings 71, 72, an annular end cap 90 is provided, held in place by a circle of screws 91 which are tapped into the end of the yoke 60. Lubrication is fed to the bearings 71, 72 via alined openings 92, 93, 94.

It will be apparent, then, assuming that the drive gear 59 is held in its reference meshing position with respect to the driven gear 39, that rotation of the nut 81, which is axially captive, will result in relative axial movement of the yoke 60, precisely accompanied by movement of the sleeve 50. The resulting change in the degree or depth of engagement between the splines 53, 56 causes the sleeve 55, and the drive gear 59 which is connected to it, to undergo slight rotational movement relative to the shaft 40, thereby changing the phase position of the drive gear 59 with respect to the shaft. This, in turn, results in a slight change in phase of the driven gear 39 and a corresponding change in phase of the plate on the plate cylinder. This, in turn, slightly changes the location of the inked impression on the cooperating blanket cylinder so that the inked impression imparted to the web 13 is slightly advanced or retarded with respect to the other inked impressions on the web which are made in the other units of the press. Since movement at the periphery of the nut is related to axial movement of the yoke 60 by a large factor which may, in a practical case, be on the order of 8:1, a highly precise and continuous adjustment in registry may be made, with any desired degree of precision. And, once set, there is little tendency for the phase relationship to change unless and until intentionally changed by rotation of the nut.

In accordance with one of the aspects of the present invention, means are provided for not only holding the drive gear 59 in precise meshing position with respect to the shaft 40 but also for retracting the drive gear into a declutched position, with the retracting movement being accommodated by the same splines 53, 56 which are utilized to achieve the precise phase adjustment. Thus, referring to FIGS. 2 and 3, a shifting yoke is provided for the sleeve 55 for causing the sleeve, and the drive gear 59 which it carries, to be positively positioned in either one of its two extreme positions. The yoke, indicated at 100, is in the form of a ring which extends around the sleeve 50 and which has an interposed ball bearing 101, the races of the bearing being axially captive in the sleeve and ring, respectively. For shifting the ring 100 between its running and retracted positions, a shifting mechanism is provided consisting of a pair of

levers

103, 104 centrally pivoted at 105, 106, respectively, and coupled, at the upper ends, to trunnion pins 107, 108 mounted on the ring. The lower ends of the

levers

103, 104 are slotted as indicated at 111, 112 for reception of aligned eccentrics 113, 114 formed on a throw shaft 115. The shaft is journaled in blocks 116. 117, with a throw arm 118 secured to the forward end of the shaft. The phasing of the eccentrics is such that when the throw arm is in its downwardly extending position (FIG. 4) the sleeve 55 and its drive gear 59 are disengaged as shown in FIG. 2, but when the arm 118 is rotated around into its upwardly extending or clutch-engaged position, the rocking of the

levers

103, 104 moves the ring 100, sleeve 55 and gear 59 to the right, with the gear 59 thereafter held in a precise position of meshing engagement with the driven gear 39.

Thus, when the clutch is disengaged the operator is free to turn the driven gear 39, and the cylinders which are connected to it, into an approximate condition of desired phasing with respect to the drive shaft, in other words, with respect to the cylinders of the associated press units. Then, when the clutch is engaged, a subsequent precise phasing adjustment may be made by rotating the nut 81.

Preferably, the pitch of the helical splines corresponds to the pitch of the helical teeth on the drive gear 59, with the splines and teeth being oriented so that the endwise thrusts which are applied to the sleeve 55 cancel one another. In other words, the axial thrust applied to the splines 56 by the splines 53 is equal and opposite to the axial reaction thrust applied by the teeth 39 of the driven gear against the helical teeth 59 on the sleeve. Thus, while the torque loading on the sleeve 55 is high, the amount of force required to hold the sleeve 55 and gear 59 in proper axial running position is relatively small. As a result, the precise positioning of the gear 59, which is required for reference purposes under running conditions, is achieved by use of a relatively light bearing 101 and relatively

light linkage

103, 104. In addition, there is no relative rotation between the cylinder and the horizontal drive shaft when clutching, due to the fact that the splines and gear have the same effective pitch, due ailowancebeing made for their different pitch diometers.

It will be apparent that the construction described above amply fulfills the objects set forth. Any desired degree of precision in phasing adjustment may be achieved and an adjustment may be made while the press is running and while the effect of the adjustment upon the printed product is being observed. The same helical splines which result in the relative rotation of the drive gear with respect to the shaft which drives it are utilized to accommodate the clutching and unclutching movement of the drive gear. The structure is, nonetheless, simple and inherently long-lived.

Iclaim:

1. In a printing press having a single drive shaft and a plurality of printing units for acting in succession on a web of paper and each having a bevel-type driven gear, a drive coupling interposed between the drive shaft and driven gear comprising, in combination a first sleeve and a second sleeve telescoped over the shaft, said sleeves having a helical spline connection between them, said first sleeve having a slidable keyed connection with the shaft and said second sleeve having a bevel-type drive gear formed on one end thereof for drivingly engaging the associated driven gear, said second sleeve having a shiftable yoke connected thereto, means for shifting said yoke for positioning the drive gear in a driving position in which the gears are meshed and a retracted position in which the gears are unmeshed so that the driven gear may be freely rotated to make gross changes in the phase posi tion thereof, said first sleeve having a positioning yoke connected thereto with means for blocking said positioning yoke against rotation, means for adjusting said positioning yoke for imparting to the sleeve slight axial movement thereby to adjust the degree of engagement of the splines when the bevel gear is drivingly meshed with the driven gear to achieve small changes in phase position of the gears with respect to the drive shaft.

2. The combination as claimed in claim 1 in which the posi tioning yoke has threaded means for achieving axial adjusting movement of the yoke.

3. The combination as claimed in claim 1 in which the positioning yoke is in the form of a collar blocked against rotation and being an opposed thrust bearing connection with the first sleeve, the collar being threaded and engaged for adjustment purposes by an axially captive nut.

4. The combination as claimed in claim 1 in which the helical splines on the second sleeve are correspondingly angled in a direction opposite to the helical teeth on the drive gear so that the endwise thrust applied to the second sleeve by the helical spline is in a direction opposite to the reaction thrust applied to the second sleeve by the helical teeth on the driven gear resulting in a minimum of net thrust on the second sleeve even under conditions of high-torque transmission.

5. In a drive for a printing press unit having a driven gear and plurality of cylinders including a plate cylinder, the combination comprising a drive shaft having first and second sleeves mounted thereon, the first sleeve being slidably keyed to the drive shaft and having a helical spline, said second sleeve being telescoped over the first sleeve and having a cooperating helical spline meshing with the spline on the first sleeve and having a bevel-type gear formed on one end for drivingly meshing with the driven gear, means for shifting the second sleeve between an engaged position in which the bevel gear meshes with the driven gear and a second position in which the bevel gear is retracted from the driven gear accompanied by relative movement at the splines, and a positioning yoke in the form of a collar telescoped over the first sleeve and coupled to it for movement in the axial direction, and normally adjustable means for axially positioning the yoke and hence the degree of engagement of the splines to change the phase position of the gears with respect to the shaft.

* t i i 9

Claims

1. In a printing press having a single drive shaft and a plurality of printing units for acting in succession on a web of paper and each having a bevel-type driven gear, a drive coupling interposed between the drive shaft and driven gear comprising, in combination a first sleeve and a second sleeve telescoped over the shaft, said sleeves having a helical spline connection between them, said first sleeve having a slidable keyed connection with the shaft and said second sleeve having a beveltype drive gear formed on one end thereof for drivingly engaging the associated driven gear, said second sleeve having a shiftable yoke connected thereto, means for shifting said yoke for positioning the drive gear in a driving position in which the gears are meshed and a retracted position in which the gears are unmeshed so that the driven gear may be freely rotated to make gross changes in the phase position thereof, said first sleeve having a positioning yoke connected thereto with means for blocking said positioning yoke against rotation, means for adjusting said positioning yoke for imparting to the sleeve slight axial movement thereby to adjust the degree of engagement of the splines when the bevel gear is drivingly meshed with the driven gear to achieve small changes in phase position of the gears with respect to the drive shaft.

2. The combination as claimed in claim 1 in which the positioning yoke has threaded means for achieving axial adjusting movement of the yoke.