US2627228A - Textile printing roll - Google Patents

Description

Feb. 3, i953 F, BROMLEY 2,627,228

TEXTILE PRINTING ROLL Filed Dec. 25. 1921s :mentor yfwrf ammi/Law G ltornegS Patented Feb. 3, 1953 TEXTILE PRINTING ROLL Frank Bromley, Swarthmore, Pa., assignor to Joseph Bancroft & Sons Co., Wilmington, Del., a corporation of Delaware Application December 23, 1948, Serial N o. 67,038

(Cl. lill- 375) 1 Claim.

This invention relates to textile printing rolls, and its nature, objects and advantages will be best understood from the following:

In textile printing, the web of fabric to be printed is passed around a very large printing cylinder, and between it and the printing rolls, the number of which varies with the number of colors in the pattern. The large cylinder usually has a suitable covering and is also provided with an endless blanket and sometimes with a web of f fabric for blotting, the web of fabric being between the blanket and the printing rolls or between the blotting fabric if employed and the rolls.

The printing rolls are driven and in turn drive the web of fabric to be printed, the blanket and the large printing cylinder, these last being driven driven by virtue of the fact that they are held against the web, blanket and cylinder under pressure.

The conventional printing rolls are either made wholly of copper or a copper sleeve mounted on a steel core or heads, then on a steel mandrel. The patterns are etched on the copper. In either construction, a large amount of copper is required and the weight of the printing rolls is very heavy. Also, because of the great weight of the printing rolls, the power requirements are correspondingly increased. The investment represented by the copper is very large.

The primary object of the invention is to provide an effective printing roll of simple and light construction which will stand up in service, greatly reduce the investment in copper required and which, by reason of its relative lightness, reduces power consumption.

How the foregoing, together with such other objects and advantages as may hereinafter appear or are incident to the invention are realized, is illustrated in the accompanying drawings, wherein- Fig. 1 is a partial side elevation and longitudinal section through a printing roll embodying my invention;

Fig. 2 is an enlarged fragmentary View partially in section.

Referring now to Fig. 1, it will be seen that my improved roll comprises a mandrel indicated as a whole by the reference character A. This mandrel is composed of an aluminum alloy having good tensile strength such as about 75,000 lbs. or more. The central portion 1 of the mandrel is of relatively large diameter, and it has a slight taper from one end toward the other. The end portions of the mandrel are turned down to provide the shaft portions or journals 8--8 and the still smaller diametered portions 9 9.

The mandrel carries a copper sleeve Il) which is interiorly tapered so that it may be driven onto the central portion l. The central portion l has a keyway I l and the sleeve I0 has a similar keyway, the sleeve being located by means of a key so that when the mandrel is driven by the source of power (motor or engine) the sleeve will be also driven as a unit.

The conventional procedure when installing the rolls in the printing machine is to pass rope slings around both ends of the mandrel. The roll is then lifted by means of the slings which operate through overhead block and falls.. The

ends of the mandrels are 9 9. The slots |2|2 are provided so that a tool may be inserted in them to prevent the slings from slipping off the mandrel when the roll is being lifted into the printing machine. Through the use of suitable slots l2-I2 these may be utilized in assisting to properly align and adjust the position of the respective printing rolls so as to correctly register the desired pattern. l

The journals 8--8 are coated with a suitable bearing metal such as stainless steel, steel or the like, as indicated at I3, to provide them with a suitable bearing surface. (The bearings for the journal are not shown). The stainless steel coatings are desirably 1%" thick. They are provided by spraying the journals 8 with stainless steel, for which purpose the surface of the journals 8 may be roughened or knurled in order to secure a good bond for the sprayed metal. Instead of knurling, a bonding or soldering material may be first applied to the surface of the journal and then the stainless steel sprayed thereon. In either fashion, a rm bond is secured between the journals and the coating. The coating is applied by a spray gun to a greater depth than 1%" and the excess metal is turned off.

Instead of spraying the stainless steel on the aluminum mandrel to form a bearing surface, it is also practical to sweat on a steel sleeve over the aluminum shaft, the steel forming the bearing surface.

In the drawings, the wall thickness of the copper sleeve is 1l and the overall diameter of the journals and their coating is ZT". From these dimensions the size of the remaining parts can be readily determined. It will be understood, however, that printing rolls vary in diameter but in all cases, according to my invention, the central portion i of the mandrel is relatively large in diameter as compared to the wall thickness of the copper mandrel.

By reason of the construction described, the printing roll is relatively very light as compared to the customary printing rolls in use these many years, but is nevertheless eiective and has long life.

In addition to the advantages secured because of a reduction in weight, the construction described possesses several quite unexpected ad-l vantages, among which may be mentioned the following:

For reasons not entirely clear to me, a printing roll constructed in accordance with the present invention does not run hot in operation. With conventional printing rolls, the temperature of the roll sometimes increasesto a point-at which one cannot bear to touch it. This is a serious disadvantage, because the printing ink dries out almost instantaneously on an overheated roll, and transfer' ofl the ink to the webA beingv printed is therefore interfered with. This is especially true Where printing pastes are used whichA contain thermosetting resins. The temperature of conventional printing rolls sometimes rises to such a point as to polymerize the thermosetting resin in the ink, under which conditions the printer must beshut down, the roll must be removed, andthe-hardened ink must becleaned out of the intaglio engravings on the surface of the roll.

Another advantage inherent in printing rolls fabricated' in accordance with the present disclosure is that the rate or temperature rise at thebearings is reduced. This makes for greatly extended bearing life, and reduces the costs ofk lubrication'.

Another advantage attainable bythe invention is that, because the structure of the roll is relatively muchY lighter in weight per unit of volume than in conventional printing rolls,.it is possible` toincrease the diameter oi' the printing roll beyond what is presently regarded as a practical upper limit on printing roll diameter. ThatV limit is determined to a large extent by the physical capacity o1 the bearingl structure to sustain, rst, the weight of the roll, and second,A the load imposed when pressure is applied to force the roll into. close contact with the web being printed. With rolls of the construction described, substantial increase in diameter, is possible without exceeding the deadweight limit of the bearings. Furthermore, the increase in weight due. to in crease in diameter is offset to some extent because the increase in diameter increases the arc of contact with the web, so that less pressure is needed to ensure thorough transfer of the printing paste from the depressions in the roll to the web being printed. Thus the dynamic load on the bearings is reduced. Still further, the greater the diameter of the printing roll, thefewer revolutions it must make per minute in order to print a given yardage at a given rate. Reducing the number of revolutions per minute reduces wear. andY temperature rise at the bearings.

It has commonly been supposed that the journals of a. printing roll should be made of the hardest,toughest, and most resilient metal available, because of the severity of the conditions under which they are used--high static load, high dynamic load, continuous operation, and little or no tolerance for play or whip. It seems most surprising that an aluminum-alloy mandrel having integral journals of the-same alloy would be capable oi meeting such rigorous demands.

I claim:

A textile printing roll consisting of a solid aluminum-alloy mandrel of cylindrical form, saidmandrel having a main body portionofV sub stantial diametertapering slightly from end to end, and having smal1erdiameter integral joui"- nal portions of the same alloy at each end, and integral' stub end portions ci the samevalloy projecting 1oeyond each journal portion; an annular jacket of stainless steel bonded' toveach oi said journal' portions and constituting a bearing surface therefor; and a copper sleeve onl the main body portion of said mandrelhaving an internal taper mating with the external taper of the mandrel, and keyed thereto.

FRANK BRoMrnY.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATESV PATENTS Y Australia Jan. 13', 1930

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