US1958211A - Method and apparatus for treating continuous films - Google Patents

Description

May 8, J. SHAW ET AL 1,958,211

METHOD AND APPARATUS FOR TREATING CONTINUOUS FILMS Original Filed y 2 1925 5 Sheets-Sheet 1 INVENTORS ,/ATT RNEYS May 8, 1934. J s w ET AL 1,958,211

METHOD AND APPARATUS FOR TREATING CONTINUOUS FILMS O'riginai Filed y 25. 1925 5 Sheets-Sheet 2 4 INVYENTORS %Ki'flwaMMM/f ATTO RNEYS J. SHAW ET AL 1,958,211

ATING CONTINUOUS FILMS May 8, 1934.

METHOD AND APPARATUS FOR THE Original Filed May 26, 1925 5 Sheets-Sheet 3 0 ATTORNEYS J. SHAW El AL 1,958,211

METHUD AND APPARATUS FOR TREATING CONTINUOUS FILMS May 8, 1934.

Original Filed May 26, 1925 5 Sheets-Sheet {l May 8, 1934. HAW 5A, 1,958,211

METHOD AND-APPARATUS FOR TREATING CONTINUOUS FILMS Original Filed May 26, 1925 5 Sheets-Sheet 5 ITED STATES PATENT OFFICE METHOD AND APPARATUS FOR TREATING CONTINUOUS FILMS Joseph Shaw and John W. Berwick, New York, N. Y.

Application May 26, 1925, Serial No. 32,868 Renewed April 1, 1933 7 Claims.

The present invention relates to the art of producing motion pictures.

The invention has for an object to provide an improved method and improved apparatus for treating continuous films of the type used in producing motion pictures in color and more particularly for treating double coated films.

Projection positives for projecting motion pictures in natural colors are produced by providing two series of images of diiferent color selected value on opposite sides of a double coated film and then dyeing the two series with suitable contrasting or complementary colors. The producing of such positives requires treatment of each side of the film independently and with different dyes.

The present invention has been developed more particularly to provide a method and apparatus for dyeing a double coated film with difierent colors and such an embodiment of the invention will be described for purposes of illustrating the principles involved. The description is illustrative merely and is not to be construed as defining the limits of the invention.

Referring to the accompanying drawings form ing a part hereof,

Figure l is a side view of a portion of an illustrative apparatus constructed in accordance with and embodying the principles of the invention.

Figure 2 is a similar view in elevation of the remainder of the apparatus.

Figure 3 is a view in end elevation of the drying apparatus shown in Figure 2.

Figure 4 is a sectional View taken on the line 4-4 of Figure 1.

Figure 5 is a.detail view of one of the adjustable discharge pipes.

Figure 6 is a perspective View showing the construction of one of the treating tanks.

Figure 7 is an end view of the same, a portion of the outer end wall being broken away.

Figure 8 is a detail view in front elevation of a portion of the drying apparatus.

Figure 9 is a detail view in side elevation of the same.

Figures 10 and 11 are detail views of parts of the drying apparatus shown in Figures 8 and 9.

Figures 12 and 13 are detail views of the film feeding mechanism.

The apparatus shown in the drawings for the purpose of illustrating the invention is arranged to provide for the continuous treatment of a motion picture film having emulsions on both sides thereof.

The apparatus is designed more particularly for dyeing a film which has been developed but ob- .circuit and sound the alarm 14.

viously its use is not necessarily limited to this use. The film is fed slowly through the apparatus at a predetermined constant speed. During its travel it is successively treated with a bleaching solution to prepare it to receive dye, washed to remove the bleaching solution, then wetted on both sides to prevent curling and thereafter dyed on one side, washed, dried, and wound on a suitable receiving reel. Provision is made for controlling the extent of treatment as desired.

Referring more particularly to the structure shown a supply reel 5 as shown at the left in Figure l is mounted on the table 6 in position to support the film to be treated. The film 7 is fed from the supply reel and through the apparatus by means of sprocket wheels 25 and 45 and other feeding devices suitably positioned at spaced points in the apparatus. The film first passes beneath a movable roller 8 with which is connected an automatic alarm device to cause an alarm in case the film breaks or when the end of the film is drawn from the reel 5. As shown, a rod 10 is connected to one arm of the bell crank 11 supporting the roller in such manner that as the roll drops, upon breaking of the film or reaching the end thereof, the rod will be projected between two contacts 12, 12 to close an electric From the tension roller 8, the film 7 passes over guide roller 15 and then down beneath a guide roller 16, forward under a guide roller 17 and along the surface of a series of treating tanks 20 to 24. The film is first treated with a bleaching solution in treating tank 20, and then washed as it passes over tanks 21 to 24. Ordinarily, it is unnecessary 99 to vary the amount of time of bleaching and only limited treatment is necessary. Accordingly, and as shown, only one tank is arranged to be supplied with this solution. The film next is washed and then passes under a sprocket feed wheel 25, over a guide pulley 26 and down into a tank 27 Where it is immersed in water to wet both sides thereof. The loop of the film which extends down into the tank 27 is held under a slight tension by means of a Weighted guide roll 30 which serves not only to keep the loop of the film in proper posit'on in the tank but also serves as a tension device to maintain the film under slight tension. The wetting of both sides of the film substantially eliminates the tendency to curl or buckle and serves to keep the film perfectly fiat during the further treatment. The advantage of thus wetting both sides of thefilm will be apparent when it is considered that otherwise the marked tendency to curl and occasional tendency to buckle is substantially eliminated thus avoiding any loss of film due to imperfect treatment. From the tank 27, the film passes over the guide roll 31 and along the treating tanks 32 to 41 where the film is first dyed and then washed. From these treating tanks the film passes beneath and partially around a driving sprocket 45 through a drying mechanism 46 to the air drying chamber 47. The drying device 46 may be of any desired type such as a blower or suction device. As the film leaves the drying chamber it is wound upon a suitable receiving reel 50.

All of the treating tanks are similar except as to length and the number and arrangement of the feed pipe connections. A description of one of the dye treating tanks will suflice for an understanding of all the similar tanks. One such is shown in Figures 6 and 7. This tank is provided with guides 55 along the top edges of the side members to support the film as it is drawn thereover. The tank is provided with inner end walls 56 and outer end walls 57, the space between the outer and inner end walls serving to receive the overflow and being provided with outlet pipes 58 to carry oif the water or treating solutions as it flows over the tops of the walls 56. Either dye or water'may be supplied to the tank through suitable feed tubes. As shown, inverted T-shaped glass tubes 59 are each connected into the side of the treating tank. The upright member 60 of each tube is connected with a water feed pipe and the horizontal member is connected with a dye feed tube. Any connection which is not to be used may be corked.

Each outlet pipe 58 is provided with a rotatable extension 61 whereby the discharge end can be turned to discharge into a tank or reservoir or to discharge into a waste trough.

In operation, the dye or water, is supplied constantly through one or more of the inlet tubes to the tank proper between the end walls 56 and flows over these end walls in a manner to maintain the fluid incontact with the lower surface of the film as it passes along the guides'55. The

height of the wall 56 is sufficient to maintain the water or other treating fluid in contact with the film while preventing contact of such end walls with the film. This avoids scratching of the film. The end walls 56 are recessed at their center portions as indicated at 62 and at their edges as indicated at 63. The recesses 62are desirable to avoid scratching of the film in case it bellies downward at the center. The recesses 63 afford a more satisfactory circulation of the treating fluid in the tank.

The several treating tanks are suitably connected with fluid supply tanks whereby a constant flow therethrough can be maintained. The bleaching solution is supplied to the treating tank 20 from a supply tank 65 from which it fiows to a supply pipe 66 whence it is fed through feeder tubes 67 to the treating tank 20. Suitable cocks 68 are provided in the connection to control the flow. The bleaching solution is discharged from the treating tank 20 into a reservoir tank 69 from which it is pumped by means of a centrifugal pump 70 back to the supply tank 65 for re-use.

A water supply is maintained in tank 71, the level of water in which is always maintained at a predetermined level by means of an automatic float valve '72. The head of water in the system is thus maintained constant insuring constant flow. Connected to the supply tank is a horizontal supply pipe 73 extending horizontally above all of the treating tanks. Suitable connections from this water supply pipe to all of the treating tanks is made by means of feed tubes '74 having cocks '75 to control the fiow of water.

Circulation of water is maintained in the wetting tank 27 by means of a connection '76 with the water supply and an overflow 77.

A suitable number of treating tanks 32, 33, etc. are supplied with dye from the dye supply tank 78 and supply pipe 79 to dye the under surface of the film to the desired extent. The tanks not in use for dyeing are supplied with water from the water supply pipe 73 and the connecting tubes so that when the film reaches the sprocket feed wheel 45 at the endof the series of tanks it will have been thoroughly washed of all superfluous dye. The film is then ready to be dried.

The dye used for treating the film in the tanks 32, 33, etc. is discharged into the reservoir tank 80 from which it is pumped by means of a centrifugal pump back to the reservoir 78 for re-use. The water used in the other tanks, however, is discharged into the waste trough76.

Drying of the film is accomplished by removing the free water from both surfaces thereof by means of air suction devices and then exposing to air in a drying chamber. The suction dryer is better shown in Figure 8. In Figure 2 the suction mechanism is shown in front elevation and in Figure 8 it is shown in rear elevation. This mechanism comprises means for flexing the film in opposite directions and suction devices adjustable to position closely adjacent and extending transversely of the film at points where it is flexed. In the particular construction shown, the flexing or guiding means consists of film guide rollers 83 and 84 together with guide rollers 85 engaging the opposite edges of the fihn to properly position it on the first roller 84. By thus flexing the film it may be maintained in a fixed position as, it passes the suction devices 86, 8'7, one of which is shown in detail in Figures 10 and 11. The suction is maintained in the suction pipes 88 and 89 by means of a suitable pump or fan 89A as indicated in Figure 2. The suction member 86 is mounted on the pipe 88 to permit a limited pivotal movement toward and from the film. This member is provided with a nozzle slot 90 arranged to lie adjacent the film as it passes over the guide roller 84, the slot being of a length to extend substantially the full width of the film. The position of the suction member 86 relative to the film can be adjusted by means of a stop screw 91 hearing against a fixed pin 92. The construction of the suction member 87 mounted on pipe 89 is substantially the same as that of the suction member 86 but a spring 94 is provided to yieldably hold the suction nozzle toward the film. It is unnecessary to use a similar spring in connection with the suction member 86 for the reason that gravity will sufliciently hold this nozzle in place.

From the suction drying devices the film passes over the guide wheels one or both of which may be frictionally or positively driven into the drying chamber.

The drying chamber is best shown in Figures 2 and 3 and consists of a relatively narrow chamber 47 together with guide spools over which the film is passed during its travel therethrough.

Two series of film guide spools 95, 96 are loosely mounted upon horizontal shafts 9'7, 98 at the top and bottom of the drying chamber. The film enters the drying chamber over the guide spools 100, 101, passes downwardly around an idle spool 101A, then up to the first of the loosely mounted spools on the upper horizontal shaft. The belt is then passed back and forth over the spools on the lower and upper shafts. Both the upper and lower shafts may be positively driven if desired but ordinarily it is sufficient if as shown the upper shaft is driven. By this arrangement there is a certain yieldable driving force exerted on each spool and the film may be kept in substantially taut condition at all points in the drying chamber without danger of excessive tension being exerted on any part thereof.

In the particular arrangement shown the lower central guide spool 103 is mounted upon a bracket 104 somewhat above the level of the lower shaft to avoid interference with a supporting bracket of said lower shaft.

It is found that the outwardly presented side of the film tends to dry more rapidly than the inwardly presented side. For this reason it is preferable to twist the film at certain points as indicated at 105, 106 during its passage through the chamber so that first one side and then the other will be presented outwardly to the drying air. By this arrangement the two sides of the film dry in about the same time and the tendency of the film to curl is substantially reduced. At the delivery end of the chamber the film passes over a sprocket wheel 109 which is yieldably driven as by means of a spring tension belt 110. The reel 50 on which the film is wound as it is delivered from the drying chamber is also frictionally driven as by means of a spring friction belt 111.

After one surface of the film has been treated with a dye of one color the other surface may be treated. If it is to be treated with a second dye in a similar apparatus including a washing tank such as the tank 2'7 in which the film is immersed, it is preferable to first dry'the film before the second treatment in order that the dye of the first treatment may not wash out in the washing tank.

The sprocket wheel 45 is driven from a main power shaft indicated in Figure 2 as by means of a vertical shaft and suitable connecting gearing.

The sprocket wheel 25, Figure l, is driven by sim ilar driving connections, not shown.

The method of treatment although in fact independent of the particular apparatus shown, has been sufiiciently described in connection with the description and explanation of the operation of the apparatus shown. It will be particularly noted that the film is wet on both sides before being I passed over the tanks containing the dyeing fiuid.

We claim:

1. A treating tank comprising parallel guides for supporting a moving film and having an inlet, the end wall of said tank having its upper edge recessed adjacent the sides of the tank and centrally recessed to conform to the curve of a sagging film, the whole end wall being of a height less than that of the guides whereby the film passing along said guides willnot contact with the end wall. and. whereby the liquid supplied to said tank will constantly overflow said end wall and will contact with the film carried by said guides Ehroughout the greater portion of the area of the ank.

2. A treating tank of the character described having longitudinal film guides and end walls the tops of which lie slightly below the film guides, said end walls being recessed at their ends and centers substantially as and for the purpose described.

3. The method of treating a double-coated -i'no tion picture film which comprises successively treating one side of the dry film with a bleaching solution, washing the treated side, wetting the opposite side and then dyeing the first treated side with a color dye.

4. The method of treating a motion picture film which comprises successively treating one side of the dry film with a bleaching solution, washing the treated side, wetting the opposite side and then dyeing only the first treated side with a color dye, and drying said film by first removing excess moisture by means of a suction nozzle and then drying 1n air.

5. The method of treating a motion picture film which comprises successively treating one side of the film with a bleaching solution, washing the treated side, wetting the opposite side and then dyeing only the first treated side with a color dye,

removing the excess moisture from said film by means of a current of air and then drying in air.

6. The method of treating a continuous film which comprises treating the under-surface only with a bleaching solution, wetting the upper-surface of said film to prevent curvature and thereafter treating the under-surface only with a dye, removing excess moisture by means of a suction device from both surfaces of the film and drying said film.

7. In apparatus for treating double coated motion picture film, in combination means for treating the under surface only with a liquid, means for wetting the upper surface of said film to prevent curvature and means for thereafter treating the under surface only with a dye, together with means for removing the excess moisture from both surfaces and drying said film.

JOSEPH SHAW. JOHN W. BERWICK.

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