US3398678A - Printing curved surfaces - Google Patents

Description

7,196 A. J. USKO 3,398,678

PRINTING CURVED SURFACE;

Filed Jan. 5. 1967 2 Sheefis-Sheet 1 I NVENTOR. ALEXANDER J. USKO mufggmw Aug. 27, 1968 A. J. usKo PRINTING CURVED SURFACES 2 Sheets-Sheet 2 Filed Jan. 5, 1967 FIG: 11?

INVENTOR. ALEXANDER J. USKO United States Patent 3,398,678 PRINTING CURVED SURFACES Alexander J. Usko, Wapping, Conn., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware Filed Jan. 3, 1967, Ser. No. 606,712 11 Claims. (Cl. 101-38) ABSTRACT OF THE DISCLOSURE A printing method and apparatus whereby ink is applied onto a portion of the lateral surface of a rotating plate by axially rotating a tapered inking roller in tangential rolling contact with an ink-receiving surface on the plate and subsequently axially rotating a curved and tapered article of manufacture in tangential rolling contact with the plate along at least a part of said inkreceiving surface.

This invention relates to methods and apparatus for forming indicia on articles. In particular, this invention relates to printing apparatus and its mode of operation, which apparatus is employed to print articles having curved surfaces.

There has been a generally increasing demand for printing nonplanar articles. More recently there has arisen a need for printing of curved and tapered articles, particularly frusto-conical containers such as drinking cups, cottage cheese containers etc. In general, the methods and apparatus which have been employed for printing cylindrical articles have been modified to print frustoconical articles. However, it has been found that the quality of print has suffered primarily in the attempt to match linear printing processes to articles having varying curvatures.

Accordingly, it is a principal object of the present invention to provide method and means for printing curved and tapered, conical or frusto-conical articles of manufacture.

It is another object of the present invention to provide improved method and apparatus for multicolor printing of curved and tapered, conical or frusto-conical articles of manufacture.

It is another object of the present invention to provide method and apparatus to print curved and tapered, conical or frusto-conical articles of manufacture at high rates of speed.

Other objects will in part be obvious and will in part appear hereinafter.

These and other objects are attained by applying an ink onto a portion of the lateral surface of a rotating plate by axially rotating a tapered inking roller in tangential rolling contact with an ink-receiving surface on said plate and subsequently axially rotating a curved and tapered article of manufacture in tangential rolling contact with said plate along at least part of said ink-receiving surface. In this invention, the curved and tapered inking roller which is used to transfer ink to the rotating plate bears a critical relationship to the other operating parts resulting in an extremely high quality print.

For other objects and a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. I illustrates a bottom view of a printing apparatus constructed in accordance with one form of the present invention.

FIG. II illustrates a side view partly in section of a cup in rolling contact with the plate taken along line 3-3 of FIG. I.

3,398,678 Patented Aug. 27, 1968 "ice FIG. III illustrates a side view partly in section of the inking roller taken along line 2--2 of FIG. 1.

FIG. IV illustrates a sectional view of the inking roller taken along line 4-4 of FIG. III.

FIG. V illustrates the side view of a turret used in one embodiment of the present invention.

FIG. VI illustrates a plate and inking means for applying multicolors.

Referring to the drawings and more specifically FIG. I, there is schematically shown a bottom view of a printing apparatus 10 comprising an 'intermitter '12 which serves to convert the continuous rotational motion of shaft '14 into the intermittent or stop and go motion of shaft 16. Shaft 16 extends through intermitter 12 with hubs 18 and 20 mounted on each end. Each hub is connected to operate in the same manner to print articles of manufacture. In order to minimize detail, only the right hand side printing mechanism is shown in full since the other side in this particular embodiment is the same. Considering the right hand side then, hub 18 is provided with a number of spindles 22 connected at one of their respective ends to hub 18 and to rotatable or hearing means 24 at their opposite ends which in turn rotatably connect article supporting assembly 26. When hub 18 is advanced against the illustrated underside of continuously rotating plate 28, a friction ring 30 located on the article supporting assembly 26 between the rotatable or hearing means 24 and article holder 32, contacts a portion 34 of the plate 28 which may be roughened causing the entire article supporting assembly 26 to rotate on rotatable or hearing means 24. A roughened portion on strip '34 is sometimes provided on the plate to enhance the frictional engagement between the plate and ring. The friction ring 30 is dimensioned to permit the outer surface of cup 36a on the article holder '32 to rollingly contact an arcuatelyshaped ink-receiving surface 38 on the side of plate '28 which has been previously inked by rolling tangential contact with the frusto-conically shaped inking roller 40 shown in FIGS. I and III.

Referring to FIG. III, the frusto-conically shaped inking roller 40 is shown having an inking surface 42 partially submerged in an ink bath 44 axially and rotatably mounted on bearings 46 and 48. The frusto-conically shaped inking roller 40 is rotated by a source of rotating power, not shown, applied to shaft 50 extending axially through said roller. The shaft 50 is in turn connected to a flexible coupling 51 to ensure even contact between the surface 42 of the frusto-conically shaped inking roller 40 and the arcuately-shaped ink-receiving surface 38 on plate 28. Ink bath 44 is retained in reservoir 52 provided with an ink supply pipe 54 and ink overflow pipe '56.

FIG. IV shows a sectional view of the inking roller of FIG. III with doctor blade attachments for removing excess ink from the inking roller prior to plate contact. More specifically, there is shown inking roller 40 with two doctor blades 58 and 60. Doctor blade 58 is provided with a resilent blade edge 62 for removing the main bulk of the ink deposited from the ink bath 44 onto the inking roller while doctor blade 60 is provided with a fine spring steel edge 64 to more precisely control the quantity of ink on the roller 40 just prior to roller contact with the ink-receiving surface 38. In general doctor blade '58 and doctor blade 60 are referred to as primary and secondary doctor blades respectively.

In the illustrated embodiment of FIG. I, the plate 28 is continuously rotated in the counterclockwise direction. The inking roller 40 is located clockwise of the supported cup 36a to permit inking of the arcuately-shaped inkreceiving surface 38 and resultant transfer of the ink to the cup. In general, the logo or image producer is arcuately formed on the ink-receiving surface 38 rather than the inking roller 40. Also along plate 28 is an interrupted section 66 which allows the subsequently supported cup 36b and hub 18 to rotate from above the plate through the continuously rotating plate 28 to permit the friction ring of the latter article supporting assembly to contact the plate 28 thereby repeating the process.

As previously indicated the curved and tapered inking roller which is used to transfer ink to the rotating plate bears a critical relationship to the other operating parts. In general the inking roller is constructed of extremely hard material preferably metal, and knurled circumferentially approximately 50 to 250 lines per axial inch. For optimum results, the inking roller is photo-chemically etched and chrome plated. Axial portions of the inking roller may then be machined or ground down by lathe or the like to limit the boundary of ink deposit. Generally, photo-chemical etching is preferred to mechanically knurling for optimum quality results. Photo-chemical etching may be carried out by photochemically masking or applying a grid pattern on the surface of the tapered inking roll and subsequently chemically etching away the unprotected metal to form a pattern of minute indentations on the surface.

The relationship between the various operating parts is critical in the present invention. More specifically, and considering FIG. III first, the inking roller 40 is fru-stoconically shaped with surface 42 partially immersed in the ink bath 44. The inking roller which may also be conical is shown in tangential contact with the arcuately shaped ink-receiving surface 38 of plate 28. Preferably, the inking roller is mounted on a shaft having a flexible portion to ensure even contact between the inking roller and plate. The words and figures generally forming the logo or image producer are usually formed on the inkreceiving surface in an arcuate fashion such that its curvature will substantially match the roll of the cup. The curvature of the arc is generally determined from its compass point and radius. The compass point is usually obtained by extending the sides on a drawing of the cup to their point of crossing. The radius of arc will vary depending on the desired location in the axial direction along the side of the cup.

FIG. II illustrates plate 28 at a later stage of rotation then that shown in FIG. III and illustrates the cup 36a in rotational and surface contact with the ink-receiving surface or logo 38 of the plate 28. As is seen more clearly in this figure, rotational momentum is applied to the article supporting assembly 26 by frictional contact between the ring 30 and roughened strip 3 4 on plate 28. Rotation of the article supporting assembly 26 is possible by a bearing connection or rotatable coupling 24, which may also be flexible, connecting the article supporting assembly 26 to the spindle 22. After the cup has been imprinted by rolling contact with the image producing surface or logo 38, rotation of hub 18 is reinitiated thereby indexing a subsequent article supporting assembly through the interrupted portion of the plate as previously indicated to repeat the operation. In this manner, the article supporting assembly 26 and cup 36a continue to advance intermittently to a station wherein the cup 36a is removed to provide holding capacity for another cup when the article supporting assembly 26 reaches a subsequently positioned cup feeding station such as shown in FIG. V.

FIG. V illustrates the general setup of stations normally employed to charge, print and discharge cups from the apparatus. In brief, there is shown a turret 70 designed to intermittently rotate counterclockwise starting from the cup feeding station 72 wherein cups are fed from stack 74 individually onto each of the mandrels 76 utilizing any conventional form of cup feeding means to separate the lowermost cup from the stack 74. The mandrel 76 is at a halted position beneath the cup feeder to await receipt of the cup. In this embodiment, the cups are held on the mandrel by a suction drawn from an orifice at the bottom of the mandrel. More specifically, a suction is applied from a source not shown through pipe 78 leading to a stationary manifold 80 mounted closely in front of the intermittently rotating hub 82 of the turret 70. On the hub 82 are eight openings 84 two of which are shown in dotted lines equally spaced around the hub, each of which leads through individual passages in the hub 82 to the inside of one of the corresponding hollow spindles 86. The passageway within the spindle extends through the rotatable bearing to a hollowed out portion 88 of the mandrel terminating at the orifice 90 on the bottom of each mandrel. The stationary manifold 80' is contoured to draw air from several of the openings 84 in the hub 82 to maintain a vacuum between the mandrel and the cup being conveyed at every station with the exception of the cup collection station 92. At this point, the opening 84 in the hub at this station is clear of the vacuum manifold thereby breaking the vacuum between the mandrel and cup and permitting the cup to be released from the mandrels and be drawn into the cup collector 92 by a vacuum applied from within the cup collector. However, it is generally desirable to aid the release of the cup from the mandrel by means for example, of an air pressure manifold 94 which causes air to flow into the opening 84 adjacent the cup collection station 92 to below the cup off the mandrel.

After a cup has been positioned in place on the mandrel from the cup feeding or dispensing station 72, the hub 82 is rotated counterclockwise passing the mandrel through the interruption of plate 96 stopping at a point which would allow tangential rolling contact of the cup with the plate. After the cup has been printed as previously described counterclockwise rotation of the hub is reinitiated advancing the mandrel to a point adjacent the cup collection station 92, after which the cup is released from the mandrel.

Also shown in FIG. V is a mechanism which will allow the inking roller to be lowered out of contact with the plate 96. More specifically, at the base of inking roller 98 is a rack and pinion gear 100. Rotating the pinion gear 102 will move the rack 104 supporting inking roller 98 up or down through guides 106a and 1061? depending on the direction of rotation of pinion gear 102.

FIG. VI illustrates an alternate embodiment of the plate of the present invention for imprinting more than one color on the type of article described above. In this instance, the mechanism is substantially the same except that a plurality of inking rollers and ink-receiving surface are employed. More specifically, FIG. VI illustrates the bottom side of a plate 110 designed to rotate counterclockwise about shaft 112 provided with an inkreceiving surface 114, inking roller assembly 116 for inking ink-receiving surface 114 and a second ink-receiving surface 118 and inking roller assembly 120. As may be seen in FIG. VI, adjacent to each ink-receiving surface are strips for frictionally engaging the friction rings of the intermittently moving turret not shown in this embodiment. It is obvious, of course, that the inking rollers must be capable of moving in and out of contact with the plate 110. This is necessary to prevent the ink-receiving surface designed to receive color from one inking roller from coming into contact with an inking roller being used to supply ink to another ink-receiving surface during the continuous rotation of the plate. FIG. V illustrates a mechanism previously described, i.e., rack and pinion gear which may also be used for this embodiment. However, any suitable means may be used which will effectively separate the plate and inking roller during part of the rotation of the plate.

The above description and particularly the drawings are set forth for purpose of illustration only and not for the purpose of limitation.

As earlier indicated, the present method of printing comprises the steps of applying an ink onto a portion of the lateral surface of a rotating plate by axially rotating a tapered inking roller in tangential rolling contact with an ink receiving surface on said plate and subsequently axially rotating the curved and tapered article of manufacture in tangential rolling contact with said plate surface along at least part of said portion. The plate generally has an ink-receiving surface, preferably resilient, to provide optimum pickup and transfer of the ink. Unless totherwise stated, the term plate as used herein also includes any adhering ink-receiving surface material.

In general, the minimum apparatus required to carry out the present invention is an axially rotatable article holder capable of supporting an article of manufacture having a curved and tapered surface, a rotatably mounted plate positioned to laterally and rollingly contact at least a portion of the curved and tapered surface of an article of manufacture on said holder, and provided radially along at least a part of the path of said rolling contact with an ink-receiving surface, and a curved and tapered inking roller positioned in tangential rolling contact with the rotating plate for transmitting ink to said ink-receiving surface. The ink-receiving surface is generally arcuately shaped to maintain optimum contact with the rolling article of manufacture and the curved and tapered inking roller. Preferably, the apparatus also includes an intermitter capable of translating continuous rotational motion to intermittent rotational motion, a hub, connected to the intermittent rotational output of said intermitter, provided with radially fixed article holders or radially extending spindles having article holders capable of supporting a curved and tapered article of manufacture or an article of manufacture having inclined axis of surface curvature.

In general, the present invention is primarily concerned with the printing of curved and tapered articles of manufacture having tapers or inclined axis of surface curvature greater than 3 degrees. FIG. II illustrates this aspect more clearly wherein a frusto-conical article of manufacture is shown having an inclined axis a, a, of surface curvature inclined from the center axis a, a, an angle equal to u. The angle a will rarely exceed 85 degrees and will more generally vary between 5 to 60 degrees. The taper or axis of curvature of the inking roller bears a critical relationship to the taper or axis of curvature of the article which is to be printed. More specifically, to insure optimum copy with a minimum of distortion, the angular variation between the inclined axis of cylindrical curvature of the inking roller and the article to be printed should not be more than 25 degrees from absolute alignment. In addition, the logo is formed in an arcuate manner preferably on the plate to form accurate non-slipping printing contact along the entire axial direction of the article surface. More specifically, the logo is imaged to conform to the axis of curvature of the article to be printed as well as being positioned with relation to the inking roller for optimum ink pickup. In the case of conical or frusto-conical articles, the distance between the printed matter on the cup and the apex formed by the extension of its sides should be close to the distance on the rotating plate between the logo or print on the plate and the center of rotation on the plate. If the variation of these two distances is more than 20 percent, distortion of the print on the article will probably result. It is found that the above-described techniques provide copy or imprint on the curved and tapered article with practically little or no distortion such as obtained generally by a linear printing process adapted to print curved and tapered, conical or frusto-conical articles.

For optimum results, it is preferred that the inking roller be separately and synchronously driven to provide optimum ink deposit on the ink-receiving surface. However, it is of course possible to employ frictional engagement such as used to rotate the cup shown in FIGS. I and III. On the other hand, it has been found most desirable to use a friction driving mechanism such as illustrated for imparting rotational motion to the article holder thereby maintaining maximum alignment between the article and ink-receiving surface during roller contact.

The present invention has been found to be particularly suitable for printing more than one color on the article. This is primarily due to the highly accurate printing con tact obtained between the surface of the inking roller and the surface of the logo resulting in an extremely fine ink transfer to the surface of hte article. In other words, a deposition or register of a second color over the first can be conveniently done without the slightest smudge since no drag exists along the width of inking and printing rolling contact. In most instances, the present apparatus would be employed to print conical, frusto-conical articles although it is possible to modify the article holder assembly to print oval surfaces having inclined axis of curvature. More specifically, the spindle would have to be modified to permit the article holder to rotate radially around the spindle so that the axis of curvature of the article coincides with the spindle axis thereby providing the same type of rolling action described and shown above with respect to the frusto-conical shaped cups.

The above description and particularly the drawings are set forth for purposes of illustration only. Any variations and modifications thereof will be obvious to those skilled in the art and can be made without departing from the spirit and scope of the invention herein described.

What is claimed is:

1. A method for printing a curved and tapered article of manufacture comprising the steps of moving said entire curved and tapered article of manufacture from an initial position through a plane defined by a rotating plate to a second printable position adjacent said plate, applying an ink onto a portion of a lateral surface of said rotating plate by axially rotating a tapered inking roller in tangential rolling contact with said plate surface along an arcuate path on said plate and subsequently axially rotating said curved and tapered article of manufacture in tangential rolling contact with said plate surface along at least a portion of said path.

2. Apparatus for printing curved and tapered articles of manufacture comprising, in combination, an article holder capable of supporting an article of manufacture having a curved and tapered surface, a rotatably mounted plate having an ink receiving surface, said plate having an interrupted portion therein of sufficient size to permit entire passage therethrough of said article of manufacture,

drive means for said article holder operatively associated with said plate so as to move said article of manufacture from 'an initial position entirely through the plane of said plate within said interrupted portion to a second printable position adjacent the plate, said plate being positioned and said ink receiving surface being situated on said plate to laterally and rollingly contact at least a part of said curved and tapered surface of said article of manufacture on said article holder and a curved and tapered inking roller positioned to roll in tangential contact with said ink receiving surface upon rotation of the plate.

3. The apparatus according to claim 2 wherein the curved and tapered inking roller is knurled providing indentations for ink pick-up.

4. The apparatus according to claim 2 wherein the curved and tapered inking roller is supported through a shaft having a flexible portion to ensure even contact between the roller 'and the ink receiving surface.

5. The apparatus according to claim 2 wherein the curved and tapered inking roller is provided with a doctor blade to remove excess ink from the roller.

6. Apparatus for printing curved and t'apered articles of manufacture which comprises, in combination, at least one rotatable article holder assembly capable of supporting an article of manufacture having a curved 'and tapered surface, a rotatably mounted plate having an interrupted portion therein of sufiicient size to permit entire passage therethrough of said article of manufacture and positioned to rotate such that at least part of its lateral surface will rollingly contact the curved and tapered surface of said article of manufacture supported by said article holder, a rotatably mounted curved and tapered inking roller positioned to rotate against at least a part of the lateral surface of said plate during rotation of the plate and a rotatably mounted turret for supporting said article holder assembly, said turret being operatively associated with said plate so as to move said article of manufacture on said article holder assembly from an initial position entirely through the plane of said plate within said interrupted portion to a second printable position adjacent said plate.

7. The apparatus according to claim 6 wherein the article holder assembly comprises an article holder and a friction ring designed to contact the rotating plate to provide rotational motion to the article holder assembly.

8. Apparatus for printing curved and tapered articles of manufacture which comprises, in combination, an intermitter capable of translating continuous rotational motion to intermittent rotational motion, a hub connected to the intermittent rotational output of said intermitter, provided wih radially extending article holders capable of supporting a plurality of said articles of manufacture having curved and tapered surfaces, a rotatably mounted plate having an interrupted portion therein of sufiicient size to permit entire passage therethrough of one of said articles of manufacture, said hub further being operatively associated with said plate so as to move at least one of said articles from an initial position entirely through the plane of said plate within said interrupted portion to a second printable position adjacent said plate, said plate having an ink receiving surface positioned to laterally and rollingly contact at least a part of one of said curved and tapered articles of manufacture on one of said article holders during at least one stage in the rotation of said hub and a curved and tapered inking roller positioned to rotate against at least a portion of the ink receiving surface during rotation of said plate.

9. The apparatus according to claim 8 wherein the ink receiving surface is arcuately shaped.

10. The apparatus according to claim 8 wherein each of the article holders include 'a spindle extending from the hub to the article holder and rotatable means associated 8 with the article holder and spindle to permit rotation of the article holder.

11. Apparatus for printing curved and tapered articles of manufacture which comprises, in combination, a hub provided with radially extending article holders each capable of supporting an article of manufacture having a curved and tapered surface, a dispensing station for feeding an article of manufacture to an article holder during one stage of rotation of said hub, a rotatably mounted plate positioned to laterally and rollingly contact at least a part of the curved and tapered surface of an 'article of manufacture supported on one of said article holders during one stage in the rotation of said hub, said rotatably mounted plate being provided with ink-receiving means, a rotatably mounted curved and tapered inking roller positioned to rotate against at least a portion of said ink receiving means during rotation of the plate, said plate having an interrupted portion therein of sufficient size to permit passage therethrough of one of said articles of manufacture, said hub further being operatively associated With said plate so as to rotate one of said supported articles from said dispensing position entirely through the plane of said plate Within said interrupted portion to a position adjacent said plate in which said supported article is printable by rolling contact with said ink receiving means, and a collection station for receiving one of said articles of manufacture from said article holder during one stage of rotation of said hub.

References Cited UNITED STATES PATENTS 1,840,466 1/1932 Quigley 101-349 2,019,537 11/1935 Keickhefer 101-39 2,310,788 2/ 1943 Hummelchen 101-350 2,917,994- 12/1959 Tripp 101-36 3,195,451 7/1965 Hoverkamp et al 101-38 3,302,580 2/1967 Edwards et al. 101-39 2,183,230 12/1939 Treece et al 101-376 ROBERT E. PULFREY, Primary Examiner.

C. D. CROWDER, Assistant Examiner.

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