Патент USA US2404689код для вставки
Jy 23, 1946. v v. CARLSEN ETAL DOGTOR'BLADE Filed Jan. 15, 1945 2,404,539 Patented July 23, 1946 L 2,404,689 l "z_.smr Es rar-sur orricsf rI_faftville; Conn., assigners to The Aspiriook Cor poration, Jewett City, Conn., `a‘ corporation' of l V Delaware ` Applicaticn January 16, 1945,-seria1’No. 572,998A l Claim. (C1. lOl-#153) u i 2 , The‘present invention relates to Ydoctor blades for use in textile printing machines and similar usesyf" More particularly, l it relatesto a -doctor blade that is protected from corrosion from the width from two to three inches, in thickness from à to als’ of aninch, and in length according Ato the length of the engraved roller, beingusually action 'of the constituentscflt'he printing pastes edge, i. e., the edge- that contacts the‘rollentis used'inj such printing, and which may be sharp some two inches longer. Their top or working ' filed to a suitable bevel and then sharpened by en‘edwhen such doctor becomes corroded without hand with anoil stone> to a Vrazor-like keenness. Their bottom edges `are ñrmly clamped between undue wear from the sharpening operation. , In printing textile fabrics, a copper roller that two brass holdersor one ofbrassand `one of4 iron, is engraved with the’d'esign `,to be printed rotates 10 tightlyscrewed together and furnished at` each against apress cylinder’and prints the design end with a supporting pivot that rests on a _brack upon a' cloth passing over the cylinder. _The color et attached to the bearingrof the rollen anda D110-, paste'is‘supplied by `a `furnisher roll _that rotates jecting lever by means of >weights or screws serves againstfthe " engraved copper roller. |I‘he fur topress the blade on the roller. . -. . , nisherroll rotates‘în` afont containing the'print 15 In` order to prevent the unequal wearing of ing pasteand,v as it contacts the engraved roll, their sharp edges, which would occur if they >were deposits the color thereon. The engraved roll, allowed'to rest continuously in one position on however, when it rotates against the cloth to’ be the roller, the doctor blades are given a fslight :to printed, should have this color paste only in the and iro movement in a direction parallel to the depressions of the engraving,"b`ut the‘furnisher 20 axis of the roller. Notwithstanding all thesepre roll deposits color not only in the'engraving but cautions, however, the edge ofthe doctor blade also wherever it contacts the engraved roll,` both in a comparativelyI short time becomes uneven within andwithout the engraved design through dueto corrosionr and when this happens, streaks out its'lenfgth.“ Accordingly, a sharp doctor blade oit color` pass under the doctor and cause smears is provided to `‘clean the engraved roll, that is, to a up‘oriìthe -cloth that is being printed. They‘then scrape off all the paste deposited thereon except must be removed and resharpened. ' where it is contained in the intaglio design. Here, again, frequent sharpening of the doctors This doctor blade is a razor sharp steel blade causes a Wearing down and ñnally a Wearing out which is kept pressed against the engraved roll of the blades. In sharpening, the printer not only goes over the bevelled face of the doctor with a file and stone, but he also must “face” it, that is, he must file and stone the bearing face that rests on the roller. This “facing” or filing of the bearing face wears down the original thick and which scrapes the excess paste therefrom so that it ilows back into the font. In general, textile fabrics are printed with vat colors, commercial colors (basics and alizarine) or aniline blacks. In printing with vat colors, the paste is alkaline whereas with commercial or aniline colors, the paste is on the acid side. 'I'hese ness of the blade and, after a certain amount of such wear is reached, the doctor blade must be pastes are very corrosive and especially so the an discarded as it no longer will fulñll its purpose. ilines, so that the edge of the doctor blade be comes eroded and uneven and unsuitable for per forming its function. `The sharpening or “getting up” of the edge 40 of the doctor blade is one of the most difficult and most important parts of the machine print As a result of this the doctor blade must be er’s work. The quality of this edge depends not removed from the machine and refiled to sharpen only upon the weight and scale of the engraving its edge some times several times during a day’s but also upon the thickness and hardness of the operation. This causes considerable loss of time in printing. Moreover, no matter what kind of 45 doctor blade, the angle at which' it rests upon the roller, the pressure applied to it, and upon paste is used, the moisture in the paste and in the both the viscosity and density of the printing air will have a corrosive action on the doctor color which it has to clean oiî. Generally speak blade, and it is common practice to remove all ing, the edge of the Well sharpened cleaning doc doctor blades at night and, before setting up the be ñled to a razor sharp edge and replaced, an tor is perfectly straight, absolutely smooth throughout its entire length, and bevelled to a operation that takes ordinarily an hour or two, all depending upon the number of rollers used. These doctor blades are made of the best qual rather obtuse angle. It is sharp as a razor and any roughness, unevenness or the slightest break in the edge is suñicient to allow color to escape machines in the morning, all doctors must again ity of medium tempered steel. They vary in 55 under it with the result that the ñnished print 3 exhibits serious defects in the form of streaks or cloudy patches of color. It is an object of the present invention to pro vide a doctor blade _which will be protected against corrosion to the greatest possible degree. and which, nevertheless, can be maintained at the required razor sharpness of the present doctor blades. ` ’ 4 doctor will not be worn thin under the sharpening operation. In the drawing, Fig. I represents schematically the arrangement of the rolls on a textile printing machine with the doctor blade in place; Fig. II _shows a doctor blade ofthe invention indetail. " KReferring to Fig. I, is the cylinder around which the blanket 2 is iap'p'ed. The cloth 3 which . It isa further object of the invention -to provide is being printed passes between the blanket 2 and a doctor blade that will not wear -down readily " the engraved roll 4. The furnisher roll 5 rotates under the sharpening operation and that as a; jin Vthefont 6 andcontacts the engraved roll 4 consequence retains its thickness and hence its eiliciency over a very long period of time. By use of the doctor bladesof'the present in vention, frequent resharpening is unnecessaryV and furthermore the doctor blade may be left in place on thev printing machine all night andthe Work which rotates in reverse direction to the rotation of furnisher roll 5. 'I'he doctor blade 'I' presses with' its plated ‘face I 0 bearing against the en-> graved rollfd, thus scraping the color from said roll except where it fills the depressions of the engraving. ~ - of printing can be resumed immediately in the In Fig. II is shown the doctor blade With its morning. This results in a saving of many hours holder or sheath 8, its steel body 9 and chromium a day in printing operations and a substantially 20 or tantalum plating l0 on one side of the steel greater output of workïfrom each machine. body.v Y L '- ~Brieily`"described, the invention consists of pro >It will be apparent that when a doctor of the viding ay doctor blade having an edge bevelled in present invention is sharpened by the printer,l theusual manner to an obtuse angle and sharp only the bevelled side of the blade Will be filed and.AV Y enve‘d'toa razor edge and having the face of the 25 stoned, as neither the ñle nor the stone will make blade, that is, that side of the blade that rests on the roller', plated With a hard, smooth, corrosion resisting metal such as chromium or tantalum. Theplatingis carried to the razor edge of the any impression on the hard, smooth chromium or tantalum coating on the bearing Aface. Asa result; there will be little wear on the plated’face and thersurface on that side will always remain doctor blade on the bearing side so that the cor 30 the same without loss of thickness of the blade. rosive acids in the printing paste do not alïect the Such a plated doctor blade will have a life several steel edge of the blade. On the other hand, if times as long as the ordinary doctor blades> now afterl use, some small amount of corrosion ofthe in use and in addition Will retain >its sharpness edge of the doctor'does take place, the master much longer, thus requiring fewer sharpenings. printer may remove it and V-resharpeh it in the 35 Having thus described -our invention,> what wel usual‘manner’sin'ce' the bevelled face of the'blade is not'ïplated.> The-plated side> of the blade, how ever,'wil1 not wear under this sharpening, as the platingefgives a very hard and smooth surface on which the file and stone will glide Without biting into .the metal. Thecoatings used forV this pur pose should be metals that are not only resistant to. thepactionjof acids. but should have a very. hard-„smoothsurface so that the bearing face cannotbe ñled vor stoned. When so coated, the claim‘is: Y . ’ . ‘4 ` 1 , ' A doctor blade comprising a steel backing beveled down to a razor sharp edge and a plating. . of chromium on the unbeveled underside extend ing to the edge, the plated side of said edge being a adapted andarranged to bear on a of aÍtextile- printing machine. v . « ' printing roller. d „ . A. VIG‘rGrOA CARLSEN. n... » Y, ALWIN HEINRICH. ,~¿ '