US2774327A - Apparatus for production of coated tape - Google Patents

Description

Dec. 18, 1956 A. B. SAINT-HILAIRE 2,774,327

APPARATUS FOR PRODUCTION OF COATED-TAPE Filed June 28, 1952 3 Sheets-Sheet l ATTORNE s Dec. 18, 1956 A. B. SAINT-HILAIRE ,3

, APPARATUS FOR PRODUCTION OF COATED TAPE Filed June 28, 1 952 3 Sheets-Sheet 2 INVENTQR fliberf ,6. 52. 191/ ATTORN S Dec. 18, 1956 A B. SAINT-HILAIRE 2,774,327

APPARATUS FOR PRODUCTION OF COATED TAPE 3 Sheets-Sheet I5 Filed June 28, 1952 TOR JZZW/ ,5 azr ATTORNE FOR PRODUCTIQN OF COATED TAPE Albert Barbier Salnt-Hilaire, Paris, France Application June 28, 1952, Serial No. 296,111 Claiins Priority, ann satisa F ee Je 1 95- 9 Claims. (Cl. 11833) This invention relates to processes and apparatus for dens ies ha m? t ack o a coatin gh a se 9a a flexible sirip, such as, for example, a magnetic sound tea e 51 a movi g pi u e Th obje f e n e t smt pr vid a Pro es n a p a u by wh th curvature of such a film, due to the shrinkage of the layer of gela in whi h overs the f e, pp s te t ha whi is to receive the magnetic sound track, may be counteracted so as to present a perfectly fiat surface to the coating apparatus, enabling a track of constant width and thickness to be obtained, and by which such a uniform track may bedeposited despite changes in the hygrometric conditions, which cause the shrinking of the galatin and consequently the curvature of the film .to vary, and changes in the viscosity of the coating medium, as well as variations in the speed of unwinding of the film.

The invention concerns first of all a process for depositing on a supple strip a narrow track of a coating medium, the width of which is comprised between 0.5 m n. and 3 mm. or more, consisting in imparting to the strip the necessary flatness by causing the face of the strip which is to be coated to pass against the tip of a nozzle, which tip is c onstituted by a cylindrical surface provided, along a generatrix of the said cylindrical surface, with an aperture of constant width, constituting a slit for the passage of the coating medium, the downstream edge of which slit is constituted by the straight edge of a' scraper disposed parallel to a generatrix' of the said cylindrical surface, in leaving free from any contact near the nozzle the other face of the strip and in causing the strip to leave the said cylindrical surface in a predetermined direction which is tangent to the said surface at a point in the vicinity of the said slit.

The invention concerns also an apparatus for carrying out the process described above, comprising a coating nozzle the tip of which has a cylindrical surface under which and in contact with which thestrip to be coated is caused to pass, the lower portion of which cylindrical surface is provided with an aperture of constant width the downstream edge of which is constituted by the straight edge of a scraper parallel to a generatrix of the said cylindrical surface, determining the width of the slit.

Another feature of the invention consists in a cylindrical support, which may be fixed or adapted to turn about its axis, situated downstream of the nozzle, at a small distance therefrom and at a predetermined level which is a function of this distance and of the thickness of'the coating to be applied, on which support is resting onits way out the face of the strip on which no track has been deposited.

According to another feature of the invention, the apparatus comprises devices for ensuring that the tension of the strip passing under the nozzle remains constant.

,According to yet another feature of the invention,

atetit ice the width of the film path of said nozzle is limited by two stops adjustable in position, 'the distance betwee'h which, preferably, isequalto that' wi'dth of the strip to -be a .7 .i. .7 r,

Other features and advantages of the present invention will become apparent' in theco'urse of the description which follows and an eiia'minationof the appended draw: ings on which there are"repre'sented, in the" way" of examples only, several embodiments of the invention.

In th j g i a,

Figure l is a diagrammatic section of acoating nozzle forming part of the apparatus of the invention;

Figure 2 is a section along 11%11 of Figure 1;

Figure 3 is ,a plan view o f a moving picturefilm coated i h ma tt c sqi in rt ac by heme 9 h 2 .16 s wn igqr s u d yi Figure 4 is a diagrammatic view, sectional .in part, of an arrangement accordingto the invention, comprising the nozzle shown in Figures '1 and 2;

Figure 5 is a similar view to that of Figure 4, illustrating an alternative embodiment'of the invention, to be used when the strip tobe coated is not provided with perforations; i x

Figure 6 is a diagrammatic view of a pressing roller for ensuring'a constant'te'nsion ofthe strip in the ararngement ShOWninFigu're'S'; i

-Figure Tis a sectional elevation showing the arrangement of Figure 5 in connection with a drying arrangement; a r J v. i V

Figures 8 and 9 are, respectively, a diagrammatic transverse sec'tion of a nozzle sii'n'ilar'to that shown in Figures l an'd' 2',"and a viejv'in plahof a film with a single row of perforations, coated with a magnetic soundtrack obtained b'y means of this nozzles" i FigureslG and 11 re? ilar views to those ofFigures 8 and 9, showing amine with two slits adapted to P W h f 'ie souhd eck im o sl a a l a a ibi iier g hti h Figures 12 and 13 'a re"side' and front elevations, re-

spectively, of a'nozzle' of" the model shownin Figures 1 and 2, "mounted on' the'lower portion fof'a hopper conai i th o t g h m shqwn in more t As'shownipriilcipally o'n Fgures 1, 2 and 3, a nozzle is use th 't p c 'i hfih h s ext al h ape' f a pn q of a cy ndrica suriacethe s of which is Pe pendi'cular to the di 'ection M t vel of the filni f which is caused to pass under and ag nst the tip of this nozzle in cre to f it r a'ma h h tra o t ng in a deposit a su't co ng medium issuingthrougli a b c iir 2510f able .c'ph a wid h pained along a lg n ratr'ia of th s idcyl kd cal su ac A doctor blade orscra er" 3', th e straight edge of which A in the "embodiment shown in Fig. '1, disposed 31m gener'atriir of this same cylindricalisurface, constitutes down e m, ds i r j There'may be morethaii one aperture or slit provided in the tip of -the" nozziajwa a more than are sha ia track isl'to be depos e on the same strip, as shownpn Figs. 10 and11'f Th an h flnh e sef m th i r wh ch hares n n ial the ih r l s fa 'e Q i o th 9 determines h thiqk estiha h c n s tance is easily adjustable either by.the raising'or the lowering of a roller14 situated atia small .distancefrom the nozzle, downstream, or by the raising or lowering ofvthe nozzle itself. r V i AS the Strip is i wht s w hthe ed e hewa ihs slit at the moment henjt leaves tangent" lly the e. l drical surfac llttie V '1 constant whatever maybe the vise" .d um and he speed ,of trayel 9 the The transverse rigidity imparted to the strip by its application against the cylindrical surface enables one to obtain the flatness required for a good coating; the distance h of the edge of the scraper 3 to the strip 1 leaving tangentially the cylindrical surface, one or two millimetres before the scraper, is in fact practically constant on the whole width of the strip, whatever may be the initial curvature due to the shrinkage of .the gelatin, 7

As the strip does not rest on any counter-support, there is no risk of scratching the under-face of the strip, which is normally coated with a photographic emulsion, whether unexposed or exposed. Moreover, variations in the thickness of the strip could not cause variations in the thickness of the coating, as would happen if the strip passed over a supporter a fixed or rotatingcylinder placed just under the tip of the nozzle. This latter advantage is a characteristic, feature of the process.

The lengthb of the coating slit is theoretically equal to the distance a between the point of tangency of the strip to the cylindrical surface and the vertical projection on the'strip of the edge of the scraper.

which is practically the same as /2rh, as h is very small; r is the radius of curvature of the cylindrical surface of the tip of the nozzle and his the thickness of the coating when moist;

In the case of very narrow tracks, the length b of the coating orifice may be raised to a maximum value of twice a in order to increase the discharge, which otherwise would be insufiicienti On the contrary, in the case of very large tracks, one must not give to b a value greater than a.

The radius of curvature of the cylindrical surface of the tip of coating nozzles for magnetic sound tracks on strips 8 mm., 9.5 mm., 16 mm., and 35 mm. width is practically comprised between 10 and 50 mm., but theselimits need not be strictly adhered to. The thickness 11 of themoist coating is of the order of 1 mm.

In order to permit a perfect transverse location of the magnetic track on the strip 1, the path of the strip under the nozzle is limited laterally by two stops 5 distant from each other by the exact width of the film. One of these stops may, however, be maintained in position resiliently by the pressure of a spring, such as 5'.

In order to obtain a uniform deposit with such a nozzle, it is necessary to ensure that the sliding motion of the strip on the cylindrical surface shall be very regular; this is obtained by imparting to the strip a strictly constant tension before its passage against the nozzle.

In the case of a perforated strip (Figs. 3 and 4,) pulled by a sprocket drum 6, a simple manner of achieving this purpose consists in paying out the strip before the nozzle by a sprocket drum 7 having the same peripheric'speed as the pulling sprocket drum 6 and to intercalate between the said paying-out drum and the nozzle a tension pulley 8 which maintains the strip under the desired tension by means of a spring 8 or of a counterweight. I

In the case of a strip without perforations (Figs. 5 and 6), the strip is maintained in tension before the nozzle by a drum 9 the spindle of which rotates against a frictional resistance that is uniform, the adhesion'of the strip f on the drum 9 being obtained either by the nature itself of the surface of the drum and a winding roller 10 (Fig;

5) or simply by a pressing roller 10' subjected: to the thrust of a spring 11. The frictional device is a classic model and its sliding motion must bevery regular.

After the nozzle, the strip passes over a cylindrical support 4 (Figs. 1, 4 and 5), as a rule rotative, the position of which determines the thickness of the coating; by-altering the height of this cylindrical support, one moves awayor approaches the strip 3 from or to the edge of the scraper 3 at the point where thestrip leaves tangentiallythecylindricalsurface. f r. I The distance 0 (Fig. 1) between the point of tangence 7 both sides of a film of 9.6 mm.

4 of the strip on the cylindrical surface of the nozzle and its point of tangence on the cylindrical support must be at least equal to a i. e. /2rh. For this minimum value, the axle of the cylindrical support is exactly under the edge of the scraper. That said support 4 may satisfactorily answer its purpose, 0 must not be higher. than r. A small value will provide a greater regularity of thickness of the coating and a great value of 0 will ensure easier adjustment. Practically, 0 will be close to /2 r.

The diameter d of the cylindrical support will be lower than or equal to 2r. The maximum value 2r is the maximum diameter it is possible to give'to d when 0:11 that the film may not be jammed between the cylinder and the support. Practically, d will be close to c.

In order to be able to adjust the level of this cylindrical support 4, it may be mounted on a bent lever 12, adapted to pivot about an axis 13 (Figs. 4 and 5); the adjusting screw 14 allows it to be displaced vertically with the desired precision.

The above arrangement is particularly employed in the following cases: I 1

Deposit of a track of 0.6 to 0.9 mm. in width, externally of the perforations, on one side or on both sides of afilmofl6mm. (Fig.11). i

Deposit of a track of 0.6 to 1.5 mm. in width, external- 1y of the perforations, on one side or on both sides of a film of mm. (Fig. 11).

Deposit of a track of 0.6 to 1 mm.

on one side'or on Deposit of a track of 0.5 to 0.9 mm. on the perforated side of a film of 6 mm. 7

Deposit of a track of width comprised between 2 and 3 mm. on the location of the optical track, on a of standard width 35 mm. (Fig. 3). p Deposit of a track of width comprised between 2 and 3 mm. on the location of the optical track, on a film of 16 mm. with one row of perforations (Fig. 9).

The examples given above are not at all limitative,-the

process according to the invention making possible the,

deposit of tracks of any width or the simultaneous deposit oftracks of same or different widths, as well on moving picture films as on the strips in plastic material or paper, whether. perforated'or not.

Fig. 10 represents the section of a nozzle for the deposit of two tracks of 0.8 mm., externally of the perforations, on a film of 16 mm. (Fig.11) and Fig. 8 represents the section of a nozzle for the deposit of 'a track of 2.5 mm. on the location of the optical track of a film of 16 mm. with one row of perforations (Fig. 9). 1 1 On Fig. 7 there is represented, in the way of example, a complete apparatus for the deposit of magnetic sound tracks on moving picture film. It comprises:

A reel 15 on which is wound the film f to be1coated, A tension regulating device, constituted, in thecase of perforated films, by the paying-out sprocket'drum 7 and the tension roller 8,

The nozzle 1, as, described above, surmounted with hopper 16 of sufficient capacity for depositing a trackof the required width along the whole film,

The roller 4, fixed or rotative, situated at'a small distance from the nozzle, downstream thereof, and per; mitting the adjustment of the thickness-of the coating to be deposited, The pulling sprocket drum 6, A drierconstituted first by a passage 17 and then by .an air-heated chamber 18, in which the filrnfollows a sinuous path so as to remain in the heated air the ,time necessary'to dry the coating, a I p A fan 19 which blows air, heated by ribbed'heating elements 20 through the chamber 18 and issuing; at 21 at the end of the passage 17 situated near thepulling drum 6, 1

A paying-out drum 22 pulling the film through. the drier before it is wound on the receiving spool,23,f A tension roller 24 permitting the tension of'the film to be maintained constant while it travels between the first paying-out drum 6 and the second paying-out drum 22, by means of a spring 23.

Figs. 12 and 13 represent in greater detail the manner in which the coating nozzle may be constructed and fixed on the hopper 16.

The nozzle 1 is secured on the lower portion of the vertical hopper 16 by means of a strap 26 and screws 27, for example; the outlet of the hopper corresponds practically in dimensions to the inlet orifice of the nozzle. The nozzle comprises also lateral bearing surfaces 28 for securing the guiding stops by means of screws 29, for example. The doctor blade 3 is secured by means of screws 30, for example, on a vertical surface 31 constituting the downstream wall of the nozzle. Owing to this arrangement, it is easy to change the nozzle 1, the doctor blade 3 or the lateral guides 5 in case of wear or damage or when a different type of film is'to be treated.

It will be clear to those skilled in this art that the method and apparatus described are by way of illustration and that the practice of the invention lends itself readily to useful modifications in both instances.

I claim:

1. An apparatus for depositing a sound track on a flexible film, comprising a nozzle a part of which is shaped externally according to a cylindrical surface, and provided with at least one slit along a part of said cylindrical surface, the upstream edge of said slit being substantially coincident with the generatrix of said cylindrical surface situated at a location where said film leaves said cylindrical surface tangentially thereto, while the downstream edge of said slit is constituted by the lower edge of a scraper situated on the extension of said cylindrical surface at a predetermined distance from the line from which said film leaves said cylindrical part, so that said lower edge of said scraper is situated at a level above the path of travel followed by said film from the line at which said film leaves said cylindrical part, means for advancing the film past the nozzle, and means for causing the film to pass over and in contact with a substantial portion of the cylindrical surface immediately upstream of the slit.

2. An apparatus as claimed in claim 1, in which is provided a cylindrical support for the film, situated at a predetermined distance from said slit, in the direction of motion of said film, the contact line of said film with said support being situated at a level lower than the level of said lower edge of the scraper, said level of said support being adjusted so as to insure a predetermined thickness of the track applied on the upper face of said film.

3. An apparatus as claimed in claim 1, in which is provided a fixed cylindrical support for the film, situated at a predetermined distance from said slit, in the direction of motion of said film, the contact line of said film with said support being situated at a level lower than the level of said lower edge, said level of said support being adjusted so as to insure a predetermined thickness of the track applied on the upper face of said film.

4. An apparatus as claimed in claim 1, in which is provided a rotary cylindrical support for the film, situated at a predetermined distance from said slit, in the direction of motion of said film, the contact line of said film with said support being situated at a level lower than the level of said lower edge, said level of said support being adjusted so as to ensure a predetermined thickness of the track applied on the upper face of said film.

5. An apparatus as claimed in claim 1, in which is provided a cylindrical support for the film, the position of which is adjustable relative to the nozzle and which is situated at a predetermined distance from said slit, in the direction of motion of said film, the contact line of said film with said support being situated at a level lower than the level of said lower edge, said level of said support being adjusted so .as to ensure a predetermined thickness of the track applied on the upper face of said film.

6. An apparatus as claimed in claim 1, including a device for applying a constant tension to the film passing against said cylindrical surface of said nozzle.

7. An apparatus as claimed in claim 1, including a device for applying a constant tension to the film passing against said cylindrical surface of said nozzle, said device comprising a paying-out sprocket drum followed by a tension roller, said device being disposed before said nozzle.

8. An apparatus as claimed in claim 1, including a device for applying a constant tension to the film passing against said cylindrical surface of said nozzle, said device comprising a paying-out drum provided with a brake adapted to exert a uniform braking action thereto.

9. An apparatus as claimed in claim 1, including a support for the film, said support being situated at a predetermined distance from said slit and at a level which is adjusted relative to the lower edge of said scraper so as insure a predetermined thickness of the track applied on the upper face of said film, a device for applying a constant tension to the film, and a drying chamber in which the film follows a devious path of sufiicient length to dry the'track on said film.

References Cited in the file of this patent UNITED STATES PATENTS 896,504 Adams Aug. 18, 1908 2,203,910 Issartel et al. June 11, 1940 2,249,200 Edwards July 15, 1941 2,332,385 Lauring Oct. 19, 1943 2,375,493 Randall May 8, 1945 2,494,378 Dexter Jan. 10, 1950

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