US1730942A - Tool for engraving rollers applicable for the treatment of photographic films - Google Patents

Description

Oct. 8, 1929. osw 1,730,942

GRAVING ROLLERS APP ABLE FOR TOOL FOR EN THE TREATMENT OF PHOTOGRAP FILMS Filed Dec. 3, 1927 2 Sheets-Sheet l Oct. 8, 1929. osw 1,730,942 TOOL FOR ENGRAVING ROLLERS APPLICABLE FOR THE TREATMENT OF PHOTOGRAPHIC FILMS Filed Dec. 3, 1927 2 Sheets-Sheet 2 6 l 5 2 1 lb im Gawald Patented Oct. 8, 1929 UNITED STATES PATENT OFFICE ANDRE OSWALD, OF PARIS, FRANCE, ASSIGNOR TO LA SOCIETE DU FILM EN CO'ULEUBS KELLER-DORIAN, 0F FRANC'E TOOL FOR ENG-HAVING ROLLERS APPLICABLE FOR THE TREATMENT OF PHOTOGrRAIPHIC FILMS Application filed December 3, 1927, Serial No. 237,525. and in France December 3, 1926.

The present invention relates to improvements in the tools for carrying out the process disclosed in the patent to Audibert No. 1,625,586 of April 19, 1927.

The parent invention relates to a mode of obtaining engraved cylindrical surfaces for the purpose of impressing with accuracy microscopic imbricated refracting elements on the face opposite to the emulsion of sensitized films used for colour photography. These elements must be perfect optically that is to say, they must present at the apex of their principal section a constant curve for an equal thickness of films this section being circular or preferably hyperbolic. The entire surface of these elements must be highly polished. The production of the engraved cylinders depends upon the pressing back of the face of the said cylinders which are per fectly smooth and brought to a specular polish by means of a tool likewise brought to a specular polish and of such a shape that the base of the impression itself preserves a specular polish.

The present invention consists in detail improvements in the tools and machines used for engraving the cylinders.

In the accompanying drawings:

Fig. 1 is a view of the tool point or extremity forming .the primary feature of this invention;

Fig. 2 is a similar view showing a modified curvature for the operative face of the tool;

Figs. 3 and 4 are modified forms of tool heads wherein the operating surfaces are hyperbolic in shape as distinguished from the cylindrical shape in Figs. 1 and 2;

Fig. 5 is a diagrammatic view of the mount ing of the tool in relation to cylindrical surface which is to be embossed;

Fig. 6 is a plan View of the arrangement shown in Fig. 5;

Fig. 7 is an enlarged view of showing more in detail the mounting of the rotatable support for the tool head; and

Fig. 8 is a plan view of a modified construction in which guiding means is provided for the tool holder.

'In order to obtain on the cylinder channels which are perfectly polished it is necessary inthe first place that the tools should be much harder than the material of Which the cylinder is constructed so that the tool is not subjected to wear on appreciable.deformation. The tool is therefore shaped in the form of a small cutting wheel or of a head of hard steel or of a stone such as the diamond, sapphire and the like.

In this latter case this head may be either cylindrical (Figures 1 and 2) with a right section appropriate to the right section of the groove to be traced upon the cylinder or else of hyperboloidal shape with appropriate section "(Figures 3 and 4).

In the case of the employment ,of a small cutting wheel which is given as an example in the parent specification, this cutting wheel must turn with suflicient friction on its axis, if it is loose on this axis, or turn at a speed adjusted so that itdoes not simply roll on the cylinder but that it exerts a. frictional effect on the cylinder.

In all cases the tool must be pressed upon the surface of the cylinder and must have no lateral play such as would cause a displacement perpendicular to the path traced on the cylinder. For this purpose, for example, the engraving tool 1 is mounted on a carrier 2 which can oscillate round an axis 3 (Figures 5 and 6). The pressure exerted by the tool on the surface of the cylinder may thus be regulated to any required extent by means of a spring at or simply by the weight of the, carrier 2. Further the eye of the carrier and the surface of the cylindrical axis 3 must engage perfectly in order to prevent any type of play in the oscillation of the carrier.

It is also possible to obtain oscillations which are perfectly free from play by the arrangement shown in Figure 7. The axis of oscillation of the carrier 2 terminates in conical points 5 absolutely regular and turning in pivots 6 of hard steel or ruby, sapphire or the like, mounted in two supports 6 the distance between which ma be regulated in the direction of the arrows '--Z. V

Figure 8 represents a modification of the apparatus designed'to obviate any risk of play and of lateral vibration. A rigid arm 8 prolongs the carrier so that the axes of symmetry or" the arm and of the carrier coincide. This arm 8 carries at its end a point 9 compelled during "working to follow a more or less deep groove of the required iorm traced in a second guide cylinder 10.

The point 9, which is free to move in the direction of the depth of the groove, will control the engraving point 1 to an extent depending upon the length ofthe rigid arm 8.

he plastic substance constituting the support of the film when pressed as far as possible by cylinders thus prepared, will take at once the curvature and thespecular left by the engraving tool.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is In combination, a rubbing tool for embossing polished surfaces comprising ,a rigid head having a hard highly polished operating point, a support for said tool including a carriage and an extension arm, and guide means coacting with said extension arm to determine the movement of the carriage and operating tool.

In testimony whereof I affix my signature.

ANDRE GSWALD.

polish

Images