Патент USA US2133137код для вставки
Oct. 11, 1938.v ' , _ H. c. HACKETT ' 2,133,137 METHOD 9F MAKING TUBES Filed Sept. 20, 1937 ' ' INVENTOR ‘ATTORNEY \' ' _ 2,133,137 Patented Oct. 11, 1938 UNITED STATES ‘PATENT OFFICE 2,133,137 Q. METHOD OF MAKING TUBES Harry 0. Hackett, Wilmington, Del., assignor to National Vulcanized Fibre 00., Wilmington, Del., a corporation of'Delaware Application September 20, 1937, Serial No. 164,800 3 Claims. (01. 154-2) The present invention relates to the making of made by winding upon a mandrel the required tubes and more particularly to the making of vul ‘ number of convolutions or layers of treated open canized ?bre tubes having relatively thick walls. stock to make a tube of given thickness after shrinkage losses are ‘allowed. Ordinarily the In.‘ the manufacture of tubes made of vul stock is drawn from a roll passed through‘ a 5v 5 canized ?bre and other chemically treated mate rial in sheet form the general practice has been treating bath containing a gelatinizing agent, to wind the material upon a mandrel until it such as a suitable acid and wound on the man drel to‘ predetermined thickness when it is auto has reached the required diameter, with due al lowance for shrinkage and while this is satisfac-' .matically severed and the wound mandrel-re 10 tory for tubes having relatively thin walls it is moved. The tube is now pured, dried and rolled 10 most unsatisfactory where a thick or heavy wall - so that the result is a completely ?nished tube tube is desired. Heretofore tubes of thick walled It with a relatively thin wall having no breaks ‘construction made by this ordinary ‘method or cracks therein. A mandrel l l is now inserted blister and crack so that one layer of material is in the ?nished tube i0, and the latter then 15 'circumferentially out of contact at various points placed in the winding or forming machine. One 16 ‘ with the I next adjacent layer of material, or form of such machine is indicated in Fig. 3 wherein. driven rollers l2 and I3 support the .While there seems to be no general rule as to the tube In in surface contact therewith. The pa number. of layers which can be successfully per stock length It is drawn from” a stock roll there are radial cracks through several layers. 20 wound without blistering and cracking because of the various diameters of ?nished tubes, it is well lmown that up to a certain relatively thin wall thickness no such defects appear. On the other'hand as soon as wall thicknesses beyond 25 this safe maximum thickness are called for, pres l5 passing through a treating bath l6 of the 20 character noted .to wind about the tube It and form the encompassing tube‘ portion l1. The desired cohesion between the surface of the tube I 0 and the stock It, as well as the succeeding ent day methods fail to prevent the layers of layers of stock is brought about through pressure 25 applied through the roll l8, and the action of material cracking during the drying and?nish the treating acid which causes the surface of the ing steps. ' Some of the objects of the present invention are 30 to provide a method of tube making wherein perfect tubes of any desired thickness can be successfully made; to provide a method wherein cracking, blistering and like defects in tubes of laminated construction are eliminated; to pro ?nished tube to knit into the ?rst superposed, layer to form a perfect union. This winding op eration continues until the thickness of mate- 30 rial superposed about the tube ID will, after 'shrinkagagive a tube of the predetermined di- ' ameter and wall thickness. Following this wind ing operation the tube is removed to soak in a 35 vide a method of tube making wherein thick ‘ purifying bath until all excess treating liquid is 35 walled tubes canbe made as perfectly as tubes leached out after which the tube is placed in a ' drierand thereafter submitted to a rolling under having thin walls; and to provideother improve ments as will hereinafter appear. In the accompanying drawing Fig. 1 repre 40 sents a perspective of a tube as partially formed in accordance with the present invention; Fig. 2 represents a perspective of the tube of Fig. 1 mounted upon a mandrel; Fig. 3 represents’ dia grammatically the step following the stage rep ‘5 resented by Fig. 2; _ and Fig. 4 represents a por . calender rolls whereby to ?nish the same at the» ?nal dimension desired. The shrinkage which occurs during thedrying action is restricted .to 46 I the secondary winding of material since the ?rst winding has completed its shrinking when first subjected to the drying operation. It has been discovered that a.tube made in accordance with the present method has its outer series of plies-45 tion, in perspective, of a ?nished thick walled tightly laminated to the surface of the inner-1 tube embodying the method of the invention. Refen'ing to the drawing-those steps believed helpful in the understanding ‘of the present in series of plies, the two surfaces being perfectly cohered throughout the whole-area. Thus while the completed tube consists of two‘ separately formed portions l0 and I7, one encompassed by 50v vention are illustrated and in the following de scription the making of a vulcanized ?bre tube - the other, the joint or seam between the two sets is taken as an example of the application of the of plies is invisible and » the effect, not only to the eye but as a physical fact, is that of a unitary ' invention. The first stage in the'method con tube having athick wall devoid of blisters, cracks, sists in making’ a complete ?nished tube It hav ll ing- a relatively'thin wall. Such a tube 10 ‘is I irregularities or other imperfections ordinarily M - 2 2,183,187 found in tubes of like thickness made by prior‘ ‘methods. ' While the foregoing describes the making of va tube through two successive winding operations, 2. The method of making a vulcanized-?bre tube having a relatively thick wall from strip material which consists in ?rst forming a rela tively thin walled tube by chemically treating the one following a completed tube, the invention isv strip with a gelatinizing agent, winding, puring, not limited in this respect in that a series of drying and rolling the wound strip material to ' winding can be made if found expedient. That produce a ?nished tube of a limited dimension, is to say each series may become a ?nished tube ’ and thereafter using said tube as a mandrel and to be used as ‘a mandrel for another series, and winding on it additional layers of similarly’treat 10 in this way a unitary wall of maximum thickness ed strip material to build up the tube to a de— 10 sired dimension, applying pressure during the can be built up free from cracks and other de ‘winding operation, and puring, drying, and roll fects now normally present in tubes of corre sponding thickness made by methods heretofore ing the tube to ?nish the same at its ?nal di mension whereby the thick walled tube formed practised. - Having thus described my invention, I ‘claim:— 1. The method of making a vulcanized-?bre tube having a relatively thick wall from strip material which consists in ?rst forming a rela tively thin walled tube by chemically treating the strip with a gelatinizing agent, winding, puring, drying and rolling the wound strip mate rial to produce a ?nished tube of a limited di mension, and thereafter using said tube as a thereby will not blister or crack. 15 3. The method of making a vulcanized-?bre tube of strip material having a relatively thick wall free from blisters and cracks which consists in forming a relatively thin walled ?nished tube of vulcanized-?bre strip material of a dimension 20 where the possibility of blistering or cracking is minimized, and thereafter using said tube as a mandrel and winding on it additional layers of ' mandrel and winding on it additional layers of i chemically treated strip material to build up a similarly treated strip material to build up the tube to a desired dimension, and puring, drying, and rolling the tube to ?nish the same at its ?nal dimension whereby the thick walled tube formed thereby will not blister or crack. relatively thick walled tube of the‘ desired di 25 mension, and puring, drying and rolling the tube to ?nish the same at its ?nal dimension. HARRY C. HACKETI‘.