US1668763A

US1668763A - Process for making blankets for printing machines

Info

Publication number: US1668763A
Application number: US117025A
Authority: US
Inventors: Dickson Harry
Original assignee: Ideal Roller & Manufacturing Co Inc
Current assignee: Ideal Roller & Manufacturing Co Inc
Priority date: 1926-06-19
Filing date: 1926-06-19
Publication date: 1928-05-08
Anticipated expiration: 1945-05-08

Description

May s, 1928. 1,668,763

H. DICKSON PROCESS FOR I AKING BLANKBTS FOR PRINTING MACHINES Filed 'June 19. 1926 manta M 8.1928.

UNITED" STATES PA-TE ILLINOIS, ASSIGNOR TO IDEAL ROLLER NT OFFICE. f

ILLINOIS, A CORPORATION 01 ILLINOIS.

PROCESS FOR IMA KING- B LANKETS FOR PRINTING MACHINES.

Application filedlune 19,

ing member having a face layer of a soft resilient material.

Heretofore, blankets for the purpose of offsetting in offset lithography, for backing the paper to be printed in newspaper presses, and for similar uses in various types of printing machinery, have been made of rubber reenforced with a backing of woven fabric. The use of rubber in any printing ma chinery has a great manydi'sadvantages, one of which resides in the fact that oils used in the printing ink cause a deterioration of the rubber. Also, the oil used for lubricating the bearings of cylinders, rol ers, and

other rotatable or movablemembers, freuently works its way onto the rubber blanket and likewise causes a deterioration in the blanket. Moreover, the wide range of temperatures encountered in a printing room affects .the rubber blanket and causes it to become unduly hardened or softened and frequently causes a swelling or shrinking of the blanket, whereby, for example, should the blanket be used for transferring subject matter on paper a distortion of such matter would result because of interference with the proper registering of the subject matter upon the paper. 1 g

It has been found, as is well known in the art, that rollers used on printing presses, typewritino machines, and other similar de-- vices, may be made of vulcanized oil, or, an

ordinary roller composition, which latter consists mainly of glue, glycerine and water, and that neither of these materials is appreciably affected by oils or temperature conditions. However. it is difiicult to cast a layer of these resilient materials on a flexible backing member so that it is of a uniform thickness and also in such manner that it properly adheres to the backing member.

Further, in the casting of such substances. it is practically impossible to eliminate air or gas cells which are usually present in the material, or if not present, are formed by the casting or mixing process.

As has been pointed out, theuse of a 1926. Serial No. 117,025.

rubber blanket is highly impracticable for the reasons mentioned, and it is therefore one of theobjects of this invention to proyide a process for making a blanket comprismg a tough flexible backing member having a face layer of a soft resilient material which is not appreciably affected by printing inks,

lubricating oils or temperature conditions.

It is a further object of this invention to provide a process for evenly distributing the soft resilient material over the surface of the backing member and holding said soft resillent material'in this evenly distributed man ner until it becomes solid.

A still further object of, this invention is to provide a process which will eliminate air or gas cells which may be present in the material or which may have formed during the casting or mixing process.

Further objects of this invention will be apparent from the description and drawings forming a part of this specification to which reference may now be had for a more co1nplete understanding of the characteristic features of this invention, in which drawlugs:

Figure 1 is an axial section of a centrifugal machine prior to the of applying the soft resilient material to the backing member;

Fig. 2 is a sectional viewthrough the mold taken on the line 2-2 of Fig. 1;

ig. 3 is a sectional view similar to that of Fig. 2 showing the application of the soft resilient material to the backing member; and i v Fig. 4 is a sectional View similar to that of Fig. 3 showing the blanket reversed and in use as an offsetting blanket.

eferring more particularly to the drawings, a centrifugal'casting machine is a mold in shown comprising a bed 11 and head and

tail stocks

12 and 13 respectively. The tail stock is adjustable longitudinally of the bed and is locked to the bed by a hand screw 14.

A cylindrical rotative shell-mold 15, having preferably a thin layer of wax 15, on the inner surface thereof is supported at its ends by conical 17, the mold being provided with

friction rings

18 and 19 that bear directly against the inner faces of said conical centering members. The centering member 16 is fixed operation centering members 16,

to a rotative drive shaft 20 which is mounted in suitable bearings 21 f the head stock. Power is transmitted to said shaft to rotate the mold by any suitable means as for example a pulley 22.

The opposite conical centering and supporting member 17 .is supported through a suitable anti-friction bearing 27 on the tail stock 13 so as to rotate freely with respect to said tail stock. The member 17 is pro vided with an apical opening through which a feed tube 28 extends, said tube being in communication with the outlet end of a fun= aid 29 that is supported on the tail stock,

and through which funnel the materials are poured into the mold. I I In the-process of )roducmg a blanket-of the class heretofore escribed, a tough flexible backing member 30 is positioned within the shell mold 15 and held snugly against the inner coaxial surface thereof by means of an adjustable clamping member 31 disposed at each end. The clamping members 31 may be formed of two semi-circular disc members held in the desired relation with each other by means of a pair of metal strips 32 on each side thereof tending therethrough and engaging slots 34 in saiddiscs.

After the mold 15 containing the backing material 30 has been assembled in the centrifugal machine 10 between the conical centering and supporting members 16 and 17, the

machine is set in motion anda quantity of the wax is not the soft resilient material in aliquid state, which has been accurately measured to pro duce a layer 35 of desired thickness, s poured through the funnel 29 into the rotating mold, and centrifugal force is developed by the rotation of the mold which causes the material to form the backing member and roduce a layer 35 of uniform thick-.

ness. .ithin a few minutes after being introduced into the mold.- and while being held ina layer of uniform thickness against the ,backing member,'-the soft resilient material becomes solid. This centrifugal force also functions to draw to the inside of the material, and eliminate therefrom any air or gas cells which maybe present ther in -r After the material has firmly "set, the machine is stop as shown in ig. 3 of the drawings. case the mold is linedwith'a thin layer ofjwax 15", the mold is subjected to heat to melt the wax and the blanket is easil removed by releasingthe clamping mem rs. Due to the elasticity of. themateria'l of the blanket,

process 'althoughitcis desirable since .it serves 'to 'removethe blanket more readily from-the mold. f

Inasmuch as the backing member is flexible and the soft resilient material formed on and fastehed by bolts 33 ex 'and the mold is remarr ed,

an essential element of this thee-curvature of the blanket is reversed and placed on a revolving cylinder on a mandrel. As it is preferable to have a margin -36 along the edges of the backing member 30, which margin is not covered with the soft resilient material 35, this margin may be produced by any preferred method for removing the resilient materialat this time.

- As shown in Fig. 4 of the drawings, the

blanket now consisting of a flexible backing member 30 having a layer of soft resilient material 35 thereon, is fastenedto a cylinder 37 of an offset press by means of bolts 38 projectingthrough the margin 36 onto the backin member 30 and into the cylinder, said bl lmket being reversed from its position in the mold and having the soft resilient material 35 outermost.

Hereinbefore it has been'stated that the i use of a rubber blanket ishighly impracticable, but that the use of an ordinary roller composition consisting mainly of glue, glycerine and water or, that the use of vulc oil, would eliminate the undesirable qualities found a rubber blanket. In the preparation of these two last named substances for use in the mold, practically the same conditions exist inasmuch as they are both primarily in a liquid state and are thereafter solidified. In the use of an ordinary roller composition, the material is poured intothe mold .in a melt- .d condition and allowed to cool and thereby become solid while the mold is rotating. In

oil and sulphur chloride in proper proportions is poured in a liquid state into the mold the vulcanizing of oil, a mixture of vegetable v which mixture, by means of. a chemical reaction, becomes solid within a few minutes after being introduced into the mold and while the mold is being rotated. Sinee'the vulcanizin oilorthe aforementioned roll- ,er composltion lacks the tenacity, and to it is re erable to uses backing member 6 meta -This metsl'backing Indy-b0 6f zinc,

hness which the rubber contains brass, 0 any other sheet metal having flexibility the degree of required. It is preferable tgremploya thicknos-of a the me pnnlximstdy 10/1000 of uri'nchin kmg'memhelj, while the thick- 55/1000 of an inch which is the cm thickness for blcnkehof ofiaet prunes,

,"Itistobe'undecstnodthstthisinvenhnn the. backing member is elastic, the blanket is not to be to a proces'sfor .ness of the vulcaniledoil my approximate ing a blanket of the dimensions hereinspecis fied inasmuch as various blankets used in connection with printing machines and the like may have-blankets of different thickness and, as has been stated, the material is accurately measured to produce a layer of any desired thickness. All dimensions are given for illustrative purposes.

Although it is considered preferable to employ a flexible metal backing member,it may be desirable to use-woven fabric in some instances. In such case, the fabric may be treated in any convenientmanner in order to obtain the necessary qualities and ad-' herence, or it might be desirable to use several layers of fabric. In any event, the process of forming the blanket by means of a cen- 1 trifugal method of producing the soft resilient material on a tough flexible backing member and reversing the blanket upon re moval from the roll so as to meet its various uses, wouldnot vary.

While this invention has been described with relation to a particular method, it is to be understood that the same is not to be limited except in accordance with, the appended claims and the prior art.

1. The process of making a blanket for printing presses and the like which comprises applying by centrifugal action a .liq-

uid material to a flexible backing member held against the curved surfaceof'a mold said centrifugal action holding said liquid material to said backing member during solidification, then withdrawing the blanket from said mold and finally reversing the curvature of said blanket.

- form,

. scribed my name. 2. The process of making a blanket for printing presses and the like which com prises applying by centrifugal force a layer ing the blanket from said mold and finally reversing the curvature of said blanket. 3. The processof making a blanket for printing presses and the like which comprises applying by centrifu al action a li uid material to a flexible acking material held against the curved surface of a mold and simultaneously eliminating air and gas cells therefrom while inv a liquid or-semi-liquid then withdrawing the blanket. from said mold and finally reversing the curvature of said blanket.

, 4. The process of making a blanket for printing presses and the llke which comprlses applying by centrifugal action a layer of resilient material to a flexible backing member held against the curved surface of a mold having a lining materialof a lowerfusingl point than-that ofthe other material, then eating said linin material to witha draw the blanket from t 1e mold, and finally reversing the curvature of said blanket.

5. The process of making a. blanket for I printing presses and thelike which cbmprises applying by centrifu al action a layer of re silient material to a exible' backin member held against the curved surface 0 a mold,

and withdrawing the blanket from said mold and finally reversing the curvature of said blanket to tool or rind the same on a mandrel to a' desired t ickness.

In witness whereof, I have hereunto sub- HARRY DICKSON.