US2315910A - Method of making rollers - Google Patents

Description

April 4 H. J. THIELKER METHOD OF MAKING ROLLERS Filed Dec. 30, 1938 m RK mL mm A 7' TOR/V5 Y Patented Apr. 6, 1943 METHOD OF MAKING ROLLERS Henry J. Thielker, New York, N. Y., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application December 30, 1938, Serial No. 248,451

3 Claims.

This invention relates to a method of making rollers, and more particularly to a method of making printers rollers such as are used to carry ink or other pigment material from one member to another, e. g. the inking rollers used in direct printing or the transfer rollers used in offset printing or other analogous procedures.

One variety of offset printing, quite extensively practised, appears in the art of making imitation wood grain finishes, imitation marble finishes and the like, in which the pattern of the material to be imitated is reproduced by any well known method, e. g. photoengraving, on a master plate, usually of metal, and is thence transferred by the usual methods of offset printing by means of a transfer roller to the surface to be ornamented. Such transfer rollers ordinarily consist of a rigid cylindrical body of wood or metal having its surface provided with an outer layer of relatively soft resilient material. Various substances have been used to make this outer layer which must present a smooth printing surface, must be impervious to and unattacked by the pigments and their vehicles used and the solvents which may be used to clean the printing sur face, and must be resilient. One substance frequently used for this general purpose is the familiar printers compound, a mixture consisting principally of glue and glycerine in proportions which will vary with the hardness desired and with climatic conditions among other factors. In the making of such rollers various procedures have been adopted, almost invariably including some step of melting and casting the compound, either directly on the roller core or as a slab to be subsequently attached to the surface of the roller. The important desideratum in any such case is to have the layer of the compound on the roller as free from bubbles throughout the mass generally as practicable and particularly to have the working surface free from bubbles, wrinkles or other irregularities.

An object of the present invention is to provide a method of making printers rollers faced with printers compound, which method shall be simple, rapid and effective to produce rollers having a smooth, clean and unflawed surface.

With the above and other objects in view, one embodiment of the invention may be presented as a method of making printers rollers which method comprises steps of pouring molten printers compound or the like on a fiat, flexible sheet of smooth impervious material, such as paper faced with lacquer, chilling the bottom of the poured compound to solidify the lower part while the upper portion remains tacky, rolling up the slab of compound together with the supporting sheet about a roller core while the upper surface of the slab in contact with the core is still adhesively sticky and soft, allowing the rolled up and adhered slab to become set throughout, and stripping off the supporting sheet.

Other objects and features of the invention will appear from the following detailed description of embodiments thereof in a method of and means for making printers rollers, taken in connection with the accompanying drawing in which the same reference numerals are applied to identical parts in the several figures, and in which Fig. 1 is a perspective view of the base member of an apparatus used in carrying on the method of the invention;

Fig. 2 is a similar view of the base with a supporting sheet and a pair of removable side rails thereon;

Fig. 3 is a view similar to Fig. 2 showing a partially smoothed out charge of molten compound on the sheet;

Fig. 4 is a similar view showing the side rails removed and a roller core in position on the partially solidified slab preparatory to rolling up the slab and supporting sheet on the core;

Fig. 5 is a view similar to Fig. 4 showing the rolling up operation partially completed;

Fig. 6 is a perspective view on a slightly larger scale of a finished roller with the supporting sheet partly removed; and

Fig. 7 is a similar view of a completed roller.

In the apparatus herein disclosed a base, shown complete in Fig. 1, has a fiat horizontal table 20 of any suitable material such as wood or any of the commercially available and suitable plastics, preferably supported for convenience on legs or cleats 2|. A transverse vertical dam 22, here shown as a piece of angle iron screwed to the top of the table, extends across the table at one end. A chilling member or plate 24 is set into the top of the table to have its smooth upper surface flush with the top face of the table. This plate 24 is composed of any suitable heat abstracting and conducting material such as metal or stone or glass or the like, a preferable material being stainless iron or stainless steel for obvious rea sons of emciency and convenience.

In Fig. 2, a compound supporting sheet 25 and an overflow sheet 26 have been laid down on the base over the chill plate 24 and removable side rails 21 have been put in place on the sheets. The sheets 25 and 26 are conveniently of the same material. A preferred construction for these sheets comprises a tough, durable, flexible lamina of any suitable material faced or formed to have its upper surface smoothly polished. Such a sheet may be made by providing a sheet of thin, tough paper or textile with a top facing of some bright finish lacquer, such as one of the cellulose acetate or pyroxylin lacquers, or a suit able varnish, enamel or the like. Or the paper may be covered with a thin metal foil. Or the sheet may be a tough metal foil without any backing or a flexible sheet of a suitable artificial resin or plastic. stance or substances used may be any which will yield a durable, tough, impervious sheet having a polished smooth upper surface, and sufficiently flexible to be wrapped together with a slab of partially solidified compound about a roller core as hereinafter described.

The side rails 21 are preferably formed, as shown, with upstanding inner Walls or faces 28, and with notches 29 to receive the vertical flange of the dam 22, and are provided with clamping means 30 ali'both ends to hold them rigidly and removably in place on the table 26. The clamps 30 at the far' ends of Figs. 2 and 3 and only partiallyshown'are' preferably like those shown complete at the near ends. Each side rail is preferably shod along its under surfac with a shoe 3! which; projects inwardly as shown to provide at each edge of the space between the rails, a vertical limit wall 32 and a horizontal supporting or gauging surface 33. The shoes 3| may conveniently be made removable from the rails proper if desired for interchange for other rails of other Widths of the surfaces 32 and 33; or the shoe may be integral with the rail proper.

' The sheet is placed on the plate 2 with the near end of the sheet 'abutted against or even turned up against the further face of the dam 22.

The subg The sheet 25 is laid with its near edge matching the terminal far edge of the sheet 25, and the twosheets are preferably locked in these positions by the pressure of the side rails and their clamps. Therails are so positioned that the opposed faces 32 or therail shoes are spaced'apart a distance equal'to the axial length ofthe roller surface to be made and the distance from the dam 22 to the far end of thesheet 25 is equal to the peripheral length of the roller surface to be made.

The distance between the rail shoes may be any desirdamount' up to the width of the plate 24, and the distance from the dam 22 to the far end of the sheet 25 may be any desired amount not extending beyond the far end of the plate 24.

When the apparatus has been thus prepared, a quantity of molten printers compound, as gauged by the skill and experience of the operator or as pre me'a'sured and prescribed, is poured on the sheet 25. By means of a scraper or doctor 34 of suitable length to extend between the side rails and rest on the two surfaces 33 and having a straight bottom edge, the molten compound is spread to form 'a slab bounded at the near end by the dam 22 and at the sides by'the vertical faces 32. A slight excess of compound is usually used andthis is allowed to spread out over the overflow sheet. The thickness of the slab thus formed is evidently equal to the vertical width of the surfaces 32.

The under side of the slab 35 of compound thus formed being separated from the cold, heatabstracting 'plate'ZA only by the thin sheet 25 is rapidlychilled andcongeals and sets to a resilient jelly, while the upper surface cools more slowly. when the 'slab has 'reached'a state in which most of its inass'has' set, but its upper surface is still adhesively soft and tacky, the rails are removed, a knife is run through the slab along the line of juncture of the sheets 25 and 26, and the sheet 26 with its small burden of waste compound is removed. A roller core is then placed in position as shown in Fig. 4.

The roller core, generally indicated at 43, comprises a cylindrical body 4| of wood, metal or other suitable material provided with axially disposed handles 42 and provided on the outer face of the cylindrical body with a firmly attached sleeve 43 of resilient material such as soft rubber,

although" in some instances this sleeve may be that the dam 22 enters the notch 44 and the rear face of the notch is applied against the rear face of the dam. The core is then rolled along away from 'theobserver, as in Fig. 5, with more or less pressure downwardly according to the softness of the yet unhardened topsurface of the slab 35. The slab being adhesive on top adheres to and is rolled up on the roller c ore together with the supporting sheet 25 which adheres to the under face of the slab, although lightly because of the polished surface of the sheet.

The completed roller with the sheet 25 adhering to its outer surface may then be set aside to allow the slab 35, now the surface layer of the roller, to harden and set completely, the roller being preferably supported meanwhile by its handles 42. When the layer 35 has 'set completely, the sheet 25 is stripped off as shown in Fig, 6, and the completed roller, as shown in Fig. '7, is then ready for use. If the roller is not to be used at once, the sheet 25 may be leftin plac on it until the time for use arrives, and will protect the working surface of the layer 35' especially from dust.

The roller core shown here is only one of many forms and constructions which such cores may take, but the slight modifications required to adapt the apparatus toother forms will be obvious. Thus if the roller has no longitudinal notch, the dam 22 will have only the height of the faces 32.

Caresh'oul'dbe taken when the sheet 25 is first spread on the-base to avoid any entrapment of air between the sheet and the base. The compound to be poured may most'conveniently and satisfactorily be melted in some container whose pouring-outlet draws from-near the bottom of the container. The compound may be melted and held in a moltencdndition in such a container until any air bubbles in-the mass have risen into the upperp'art. Cbmpound'poured from the bottom will then be subs'ta-ntially free from bubbles andwill iyield a satisfactorily homogeneous and unfla'wed slab. g I

The embodiments herein-disclosed are illustrative and maybe-modified and departed fromvariously without departing from the spirit and scope of the inventionfas pointed out-in and limited solely by the appende'd claims.

What is'claimedis:

l. The method of making rollers whichmethod comprises'steps of forining a uniformly thick flat layer of molten roller surfacing material, chilling 'one faceonly of the-layer to cause the material to set-as aslab having one solidified face and one adhesively'soft face, rolling 'up the slab about a roller core with the' soft 'face of the slabin contact with the core and while thesoft face is still adhesively sticky, and allowing the rolled up and adhered slab to set throughout.

2. The method of making rollers which method comprises steps of pouring molten roller surfacing material on a flexible impervious sheet, causing the material to partially set as a slab supported on the sheet, rolling up the slab and sheet together on a roller core to cause the slab to adhere to the core with the sheet outside, causing the slab to set throughout, and stripping the sheet from the slab adhered to the core.

3. The method of making rollers which method comprises steps of pouring molten roller surfacing material on a flexible impervious sheet, spreading the molten material into a layer of uniform thickness on the sheet, chilling the sheet to cause the material to partially set as a slab solidified at the bottom thereof and tackily soft on its top surface and supported on the sheet, rolling up the slab and sheet together on a roller core to cause the slab to adhere to the core with the sheet outside, causing the slab to set throughout, and stripping the sheet from the slab adhered to the core.

HENRY J. THIELKER.

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