US3390633A

US3390633A - Mounting device and method for applying a printing plate to a cylinder

Info

Publication number: US3390633A
Application number: US664504A
Authority: US
Inventors: Frank E Boughton
Original assignee: In Line Products Inc
Current assignee: In Line Products Inc
Priority date: 1967-08-30
Filing date: 1967-08-30
Publication date: 1968-07-02
Anticipated expiration: 1985-07-02

Description

July 2, 1968 F. E. BoUGH-roN 3,390,633

MOUNTING DEVICE AND METHOD FOR APPLYING-A PRINTING PLATE TO A CYLINDER Filed Aug. vso, 1967 5 sheets-sheet 1 l FIG. /12

A LA

gt. es f l5-f d n I? 23mm' f 52 July 2, 1968 F. E. BOUGHTON 3,390,633

MOUNTING DEVICE AND METHOD FOR APPLYING A PRINTING PLATE TO A CYLINDER Filed Aug. v30. 1967 5 Sheets-Sheet 2 `IIIIIIH I .umm ifi u 56 1 55 .w 43 A Q July 2, 1968 F. E. BOUGHTON 3,390,633

MOUNTING DEVICE AND METHOD FOR APPLYING A PRINTING PLATE TO A CYLINDER Filed Aug. 50, 1967 5 Sheets-Sheet 3 FIG. 6 ,5 .1 7 '8 United States Patent O 3,390,633 MOUNTING DEVICE AND METHOD FOR APPLY- ING A PRINTING PLATE T A CYLINDER Frank E. Boughton, Chicago, Ill., assignor to In-Line Products, Inc., Northfield, Ill., a corporation of Illinois Continuation-impart of application Ser. No. 493,826, Oct. 7, 1965. This application Aug. 30, 1967, Ser. No. 664,504

2 Claims. (Cl. 101 401.1)

ABSTRACT 0F THE DISCLGSURE A flexible printing plate mounter and method wherein a table and cylinder move toward each other to cause the engagement of the sticky side of the plate with the cylinder along an axial line after register has been checked optically, the mounter including a flexible sheet supporting the plate which can be folded on itself to wrap the plate about the cylinder.

This application is a continuation-in-part of my copending application Ser. No. 493,826, now abandoned, filed Oct. 7, 1965.

Summary of invention The apparatus of this invention constitutes an improvement on that type of mounter-proofer wherein the printing plates are held on the plate cylinder by means of a two-sided adhesive commonly referred to as sticky back. In excess of 85% of iiexographic printing plates are secured in this fashion. The sticky back is used in either of two ways. With one method, the back of the plate is ailixed to one surface of the sticky back before placing this composite on the plate cylinder. The other is to wrap the sticky back around the plate cylinder and then position the rubber plate on it.

In either method, the function of a plate mounting device is to assist in accurate positioning of plates on the cylinder, particular on multicolored and multiplate jobs which mus-t be in register.

The previous mounter-proofers consist essentially of three means of measuring-a dividing head for properly spacing multiplates around a cylinder, a horizontal scale for measuring across the cylinder and a vertical scale for measuring circumferentially around the cylinder-the latter scale having compensation for the pla-te thickness. With all of the prior devices, it is exceedingly difficult to obtain a speedy and exact positioning of the plates. The plates are mounted visually and to a large extent manually and in most cases they have to be moved after the original positioning. In the prior art devices, each was characterized by a weakness residing in the necessity of lifting the plate from the sticky back or lifting the premounted sticky back plate from the cylinder to reposition it. In this operation, the plate can be stretched, compressed or distorted. Even if none of these occurs, it is diiiicult to lift an average size plate for a movement of about 3&4 and practically impossible to shift one a distance of the order of 0.01".

These difficulties are avoided by the instant invention and the provision of apparatus which makes accurate and easy positioning of the printing plate constitutes an important object of the invention.

Other objects and advantages of the invention may be seen in the details of construction and operation set down in this specification.

The invention is explained in conjunction with an illustrative embodiment, inrwhich FIG. 1 is a perspective view of apparatus embodying teachings of the invention;

ICC

FIG. 2 is a fragmentary enl-arged perspective view of a portion of the apparatus seen in FIG. 1;

FIG. 3 is an enlarged fragmentary perspective view such as would be seen along the sight line 3 3 applied to FIG. 1 and showing details of a portion of the proofing portion of the apparatus;

FIG. 4 is another enlarged fragmentary perspective view of a portion of FIG. 1 such as would be seen along the sight line 4 4 applied thereto;

FIG. 5 is still another enlarged fragmentary perspective view of a portion of FIG. 1 such as would be seen along the sight line 5 5;

FIG. 6 is a fragmentary elevational view of a portion of FIG. l such as would be seen along the sight line 6 6 applied to FIG. l; and

FIG. 7 is an enlarged fragmentary sectional view taken along the line 7 7 applied to FIG. 6.

Basic structure In the illustration given, the numeral 10 designates generally the frame of the apparatus and is seen to include a pair of vertical standards 11 (FIG. l) which are inter-connected at the tops thereof by means of cross-bar 12. At the bottoms of the standards 11, I provide pedestals 13, which are equipped with adjustable feet 14. Through the use of the adjustable feet, it is possible to position the working portion of the apparatus at different heights to accommodate different artisans.

The frame provides a mounting for a plate cylinder generally designated 15 which is seen in the central portion of FIG. 1. The plate cylinder 15 is equipped with axially outwardly ex-tending journals 16 which are carried in bearing or support brackets 17 provided on each standard 11 (see particularly FIGS. 4 and 5). The journals are secured within the support bracket 17 by means of holddown dogs 18, again two being provided for co-action with the brackets 17. The dogs 18 are pivotally mounted on the brackets 17 and contoured to readily receive the journals 16 and retain them in the V-notch configuration of the bracket 17.

Plate applying means The invention is particularly concerned with means for accurately and readily applying a flexible printing plate as at 19 (see FIG. 7) to the plate cylinder 15. In one embodiment of the invention, I find it advantageous to insure proper adhesion of the plate 19 to the cylinder 1S by means of employing a Wrapping element 20 (still referring to FIG. 7). The element 20 includes a flexible film which can be converted to the configuration designated 20' wherein the plate 19 is urged against the surface of the plate cylinder 15 and adhered thereto by virtue of the above-mentioned sticky back.

Prior to this operation, i.e., the application of the plate to the plate cylinder, plate 19 to the plate cylinder 15, there is the need to properly position the plate 19 and thereafter bring the plate into line contact with the cylinder 15.

Plate positioning means For applying the plate 19 to the plate cylinder 15, it is first necessary to immobilize the cylinder 15 in a predetermined position and I achieve this by means of locking the dividing head spur gear 21 in a given position. As can be seen from a consideration of FIG. 2, the lefthand standard 11 is equipped with a removable pi-n 22 which is positioned between adjacent teeth of the -gear 21. This immobilizes the plate cylinder 15, the gear 21 having been previously installed on the lefthand journal 16 in a proper alignment for installing the various plate cylinders. For this purpose, conventional indicator markings are employed. Ultimately, if the cylinder 15 is to be equipped with a plurality of plates 19, the gear 21 will be stepped or indexed in discrete amounts so as to bring different portions of the surface of the cylinder 15 into confronting relation with successive plates 10. The plate cylinder 15, when installed in a press (not shown), is operated by means of its own spur gear or cylinder 23 (see also FIG. The markings on the gear 21 can be seen on the inside face thereof as depicted in FIG. 4 and the pin 22 is seen to be provided as part of a lever arm 24 biased upwardly by means of a spring 25 (still referring to FIG. 4). Once the plate cylinder 15 has been immobilized, as in the fashion just described, the plate 19 is placed upon a transparent platform generally designated 26.

The table or platform 26 is advantageously equipped with a plurality of spaced indicator lines as at 27 (see FIG. 5), which may be scribed into the transparent plastic to a depth of about 0.005. Transverse lines as at 28 (see FIG. 1) are also provided so that the scribe lines on the plate 19 can be accurately aligned in two directions with those provided on the table 26. It will be appreciated that the adhesive on the plate 19 (if so provided) is on the upwardly facing surface. The alignment contemplated in the invention is a visual one achieved according to the showing in FIG. 7 wherein the symbol E in the upper lefthand portion of FIG. 7 designates the eye of an artisan who is viewing the underside of plate 19 by virtue of an image reliected from a mirror 29. The mirror 29 is seen to be clamped within and supported by a bracket or pedestal 30 (refer to the central portion of FIG. l). A similar bracket 31 is provided on the rear of the apparatus (see FIG. 7) and the brackets are in turn supported on transversely extending slides 32. The slides 32 are mounted on transversely extending rods 33 so that the mirror 29 can be positioned for proper reliection irrespective of where across the surface of the plate cylinder the plate 19 is to be applied.

Also aiding in the alignment procedure are the lamps 34 which are also carried by the slides 32. As seen in FIG. 6, each light is carried on a sub-pedestal 35 which is slidably mounted fore-and-aft of the machine in C-shaped guides 36, the guides 36 being supported on the slides 32. Thus, by virtue of grasping the hand knob 37, the artisan is enabled to move the lamps fore-and-aft to obtain the best illumination of the various alignment marks on the table 26 and plate 19. This connection is to be appreciated that the lamps 34 are directed upwardly and at a slight angle so las to develop superior illumination (i.e., a slight shadow) for the alignment procedure.

Plate engaging means After the plate 19 has been properly aligned with the

register lines

27 and 28 on the table 26, the plate cylinder 15 is lowered to the position seen in the drawing wherein there is essentially line contact between the plate cylinder 15 and the rubber printing plate. This is achieved through a rack and pinion generally designated 39 in FIG. 5. For this purpose, each of the standards 11 is equipped with a pair of bearing brackets as at 40 and 41 (see the lefthand side of FIG. 1) in which an elongated, vertically extending rack member 42 is supported. Extending between the standard 11 and journaled therein is a crossshaft 43 (see FIGS. 1 and 5) and fixed to the cross-shaft 43 are the two pinions 44. The right end of the shaft 43 is coupled to a compound gear box generally designated 45 (seen only in FIG. 5) which is operated by a handleequipped handwheel 46. The gear box permits controlled lowering plate cylinder 15 without the possibility of overrun because of gravity.

After the plate cylinder 15 has been lowered by operation of the rack-and-pinion mechanism 39, the wrapping element is operated as described hereinbefore in connection with FIG. 7. The wrapping element 20 includes a sheet of transparent film 47 equipped with rigid tubes 48 at the fore-aud-aft thereof. The film 47 may be clamped to the table 26 centrally of each side thereof as by means of clips 49. The tubular elements 48 in combination with the clips 49 insure that the film 47 is substantially unwrinkled so that the enveloping action contemplated (as shown in FIG. 7) results in a smoothly applied printing plate (to the plate cylinder 15). If the plates are larger than approximately 4" x 6 when the cylinder diameter is sufiiciently great as to obstruct the artisan from putting his arm between the plate cylinder and proofing drum, I prefer to grasp only one side edge portion of the film 47, for example the edge element 48 adjacent the eye E of the artisan. After the front half of the plate is wrapped and afiixed to the cylinder, the rear half is wrapped by turning the plate cylinder manually. The top of the plate cylinder thus is rotated toward the rear of the machine. This causes the unaiiixed end of the plate to be drawn forwardly and wrapped to the plate cylinder as the front half is securely fixed and is the means by which the plate is drawn forward.

Operation In the operation of the device, the initial step is to lock the gear 21 in place on the journal 16 of the plate cylinder 50, the plate cylinder 15 having previously been positioned within the bearing brackets 17 provided on the rack members 42. For the purpose of locking the gear in place, a coupling 50 (see FIG. 1) is employed 'which is adapted to be fixed in a predetermined position to the journal 16 While being bolted to the gear 21. Thereafter, the gear 21 is fixed against rotation by means of the pin-stop 22 provided as part of the lever 24 (see FIG. 4). The particular orientation of gears 21 that is selected can be readily ascertained from the markings 51 (FIG. 4) on the inside face of the gear 21.

Now the plate 19 is positioned on the transparent table 26 with mirror 29 therebelow. The lights 34 are illuminated and the angle of the lights is such to create a shadow so that the

lines

27 and 28 on the glass and, more irnportantly, the scribe lines on the printing plate 19 are readily visible. The mirror 29 is laterally moveable as indicated by the horizontal arrow applied to FIG. l, this being achieved through the cooperation of the Slide 32 and rod 33. Additionally, the light-supporting plate 35 is moveable fore-and-aft within the guide 36 as indicated by the generally vertical double-ended arrow las in FIG. 5.

The table 26, like the mirror 29, has one degree of freedom. The table 26 can be moved laterally by means of a micrometer generally designated 52 (see FIGS. l, 5 and 6). This gives infinite lateral spacing relative to the one-inch spaced-apart lines 27 provided on table 26. No fore-and-aft movement of the table 26 is available or necessary inasmuch as the lateral center line (defined by the clips 49) is aligned with the axis of the plate cylinder 15. The forc-and-aft immobility of the table 26 is provided for by virtue of the side plates 53 (see particularly FIG. 5) which are anchored to the standards 11. The previously-mentioned rodsr33 couple the side plates 53 together and provide the means for positioning the mirror 29. A second pair of rods 54 couple the side plates 53 together adjacent their upper corners and provide the means for controlled lateral movement of the table 26. In FIG. 5, for example, the micrometer is seen to be mounted within a bracket 55 which in turn is fixed to the associated rod or shaft 54. The micrometer plunger 56 bears against a bracket 57 which is coupled to the table 26. The table 26 is coupled to the bracket 55 by means of a spring 58 (see also FIG. 7) so that positive contact is insured between the micrometer 52 and the table 26.

Incident to the alignment of the scribe marks on the plate 19 with the

register lines

27 and 28, both the mirror 29 and the lights 34 can be moved so as to develop maximum contrast and insure as close to perfect alignment as is visually possible, the lights 34 being moveable fore-and-aft on the plate 35 supported within the guide 36 while the mirror 29 is moveable laterally by virtue of the co-action of the slide 32 with the rods 33. The procedure usually includes the mounting of a plurality of plates 19 on the plate cylinder 15 so as to develop a uniform draw when the plate cylinder 15 is mounted within a printing press (not shown). By use of the inventive construction, I minimize any tendencies to stretch the exible printing plates 19 which on occasion with past devices have been stretched as much as 1&2.

After the plates 19 has been properly positioned on the table 26, the compound gear box 45 is operated to bring the plate cylinder 1S into line Contact with the plate 19 and in this connection a stop may be provided limiting the approach of the plate cylinder 15 to the glass to a spacing of the order 009-0120", the range of thicknesses of the plates 19 so as to prevent a breakage of the glass of which the table 26 is constructed. This may take the form of an adjustable idler gear 23a (see FIGS. 1 and 5). After line Contact has been established, the wrapping element 20 is wrapped in the fashion indicated schematically in FIG. 7.

Thereafter, the printing plate, having been mounted on the plate cylinder 15 is moved upwardly by reversing the motion of the hand wheel 46 and moving the plate cylinder 15 upwardly toward the proofing roll 59 (see FIGS. 1 and 3). Ultimately the plate cylinder 15 is moved close enough to the proofing roll 59 so that the gear 23 engages the proofer gear 60 with particular points on the two gears in alignment as indicated by the doubleended arrow 61 provided on FIG. 1. At this point, the plate cylinder 15 is driven but is not close enough to the proofing cylinder 59 for printing contact. The plates are inked with a hand-brayer roller as cylinder 15 is being revolved-as by crank 63 or, alternatively, a fractional horsepower motor. At this time, the latching mechanism generally designated 62 in FIG. 3 is unlatched. Alternatively, nip rolls can be associated with the proofing roll 59 so as to provide a continuous web of paper for proof- Advantageously, the lights are arranged at an angle of 45 to each of the

lines

27 and 28, i.e., when viewed from above. Also, the lights are upwardly inclined at an angle of about 20 to the horizontal-as when viewed from the side. Beneficial results in the illustration given are obtained with angles of inclination of about 15 to i the horizontal.

I find that accuracy in positioning is obtained through the use of masking

strips

64 and 65 positioned on the underside of the plate 26 or in the form of

strips

64 and 65 provided on the upper surface of the mirror 29. The provision of the strips perform a function much akin to the rear sight of a rie so as to obtain exact plate alignment. This insures that the eye E of the viewer will always -be in the same position and avoid any error which occurs by changing the angle of refraction. For example, in the illustration given, there is a 0.045 gap between the scribed line on the glass 26 and the guide line on the shoulder of the plate 19 which allows for the error. The strips 64 and 65 (alternatively 64 and65) need only be V16" or 1/s" wide and the gap may vary from between 1/a" to 3/16 in order to get advantageous results.

While in the foregoing specification a detailed description of an embodiment of the invention is set down for the purpose of illustration, many variations in the details herein given may be made by those skilled in the art without departing from the spirit and scope of the invention.

I claim:

1. A method employing a printing plate mounting apparatus comprising a frame equipped with means for supporting a plate cylinder in a predetermined position, a subframe on said frame with a transparent support portion for supporting a printing plate in juxtaposition below said plate cylinder, means on said frame for moving said plate cylinder and subframe toward each other to contact said plate with said plate cylinder along an axial line, said subframe being equipped with mirror means under said subframe for visually viewing the location of said printing plate, comprising the steps of:

(a) positioning a transparent ilexible member on said transparent surface portion in confronting relation to said cylinder,

(b) providing said support portion and printing plate with locating scribe lines,

(c) fixing said flexible member in a predetermined position on said surface portion relative to said printing cylinder, said flexible member having at least one side edge loosely mounted on said surface portion and extending in a direction parallel to the direction of said printing cylinder axis,

(d) placing the said printing plate between the printing cylinder and said flexible member with the printing face in supporting engagement with said flexible member, said exible member side edges extending beyond the respective edges of the printing plate,

(e) registering the printing plate relative to said flexible member by visually comparing the said scribe lines on said printing plate and support portion through said optical means,

(f) providing adhesive means between said plate Cylinder and said printing plate,

(g) moving said plate cylinder and subframe toward each other to contact said printing plate with said plate cylinder along the said axial line, and

(h) grasping said exible member along at least its loosely mounted side edge and wrapping the same upon and circumferentially about said cylinder to apply said plate to said cylinder.

2. A printing plate mounting apparatus comprising a frame equipped with means for supporting a plate cylinder in predetermined position and a subframe for mounting a printing plate, and means on said frame for moving said plate cylinder and subframe toward each other to contact said plate with said plate cylinder, said subframe being equipped with mirror means whereby locating lines on said subframe and on said plate are visually comparable, said subframe being equipped with a transparent wrapping member provided in supporting relation relative to said plate, said wrapping member being foldable to circumferentially apply said plate to said plate cylinder, said wrapping member including rigid elongated elements provided in the side edges thereof for rigidifying said member.

References Cited UNITED STATES PATENTS 2,113,655 4/1938 Kellie lOl-415.1 XR 2,428,428 10/ 1947 McCarter 101-426 2,559,533 7/1951 Daniels lOl-426 2,907,274 10/1959 Taylor lOl-401.1

OTHER REFERENCES German printed application 1,132,154 June 6, 1962,

Finke.

ROBERT E. PULFREY, Primary Examiner.

I. R. FISHER, Assistant Examiner.