US2096231A

US2096231A - Horizontal type film developing and drying machine

Info

Publication number: US2096231A
Application number: US78884A
Authority: US
Inventors: Harris N Ensign; Harry A Hanson
Original assignee: PARAMOUNT PRODUCTIONS Inc
Current assignee: PARAMOUNT PRODUCTIONS Inc
Priority date: 1936-05-09
Filing date: 1936-05-09
Publication date: 1937-10-19
Anticipated expiration: 1954-10-19

Description

Oct. 19, 1937.v H. N. ENslGN ET Ax. 2,096,231

HORIZONTAL TYPE FILM `DEVELOPING AND DRYING MACHINE Original Filed March 13, 1935 `5 Sheets-Sheet 1 P- I l I Oct. 19, 1937. H. N. ENslGN ET Al. .l 2,096,231

kHORIZONTAL' TYPE FILM DEVELOPING AND DRYING MACHINE 5 sheets-sheet 2 Original Filed March 13, 1935 Oct. 19, 1937.

H. N. ENSIGN T AL HORIZONTAL TYPE FILM DEVELOPING AND DRYING MACHINE Original Filed March 13, 1935 5 Sheets-Sheet 3 Oct.` 19,1937'. H. N. ENslGN E1- A1.

HORIZONTAL TYPE FILM DEVELOPING AND DRYING MACHINE Original Filed March 13. 1935 5 Sheets-Sheet 4 ct. 19, 1937. H. N. ENslGN ET AL HORIZONTAL TYPE FILM DEVELOPING'AND DRYING MACHINE Original Filed March 15, VV1935 5 Sheets-'Sheet 5 \m\\ r W Patented Oct. 19, 1937 UNITED STATES PATENT OFFICE HORIZONTAL TYPE FILM DEVELOPING DRYING MACHINE Substituted for abandoned application Serial No. 10,840, March 13,` 1935. This application Mayr 9, 1936, Serial No. 78,884

14 claims. (el. 271-23) This invention relates generally to developing and drying machines for motion picture film, and

may be considered as dealing with improvements in the type of film developing machine generally disclosed and claimed in our prior Patent No. 2,008,439, dated July 16, 1935, entitled Method of and apparatus for moving nlm strips through liquid baths. The present application is a continuation-in-part of, and a substitution for, our prior applications entitled Horizontal type iilm developing and drying system, led March 13., 1935, Ser. No. 10,840, and Film drying machine, filed March 13,1935, Ser. No. 10,841.

Our prior patent referredA to above discloses a developing machine which may b'e described as of a horizontal type, in which the lm is threaded in horizontally elongated vconvolutions over the film rollers mounted on horizontal shafts at the two ends of the comparatively fiat horizontal tank, the lower runs of the film passing under iilm rollers on a central shaft which is mounted a short distance below the level of the end shafts to give a triangular form to the lm path. The rollers at one end of the tank are driven to move the -film. The tank bottom slopes downwardly from each end toward the middle, in parallelism with the lower runs of the lm. The liquid bath is injected between the lower nlm runs and the tank bottom with an initial velocity in the direc- O tion in which the film moves, and flows initially with the film convolutions is the substantial avoidance of streaking or Mackie line" effects which are commonly encountered in developing motion picture film.

It is the object of the present invention to provide improvements in film moving and controlling mechanism especially adapted to developing machines of the character mentioned.

It is a. further object of the invention to provide improvements in nlm moving and controlling mechanism adapted for use in a lm drier.

Having set forth generally the type of machine to which the present invention most particularly appertains, the present invention will now be best vunderstood without further preliminary discussion by referring at once to the following detailed description of a present preferred embodiment thereof, reference for this purpose being had to the accompanying drawings, in which:

Fig. 1 is a. side elevation of the lm developing and drying machine of the present invention;

Fig. 2 is a section on line 2-2 of Fig. 1 showing speed control means for the machine;

Fig. 3 is a. detail section. taken on line 3-3 of Fig. 2;

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Fig. 4 is a longitudinal section of the nrst or film developing unit of the machine taken as indicated by line 4-4 of Fig. 5;

Fig. 6 is a detail section taken on line 6-6 of- Fig. 5;

Fig. 6a shows a modified form of lm driving wheel;

Fig. l is a detail section taken on line 1-1 of Fig. 5;

Fig. 8 is a plan view of the last element of the drier unit, the upper Wall of said unit being broken away;

Fig. 9 is a section taken on line 9 9 of Fig. 8;

Fig. 10 is a detail section taken on line I0-I0 of Fig. 8;

Fig. 11 is a detail section taken on line II-II of Fig. 8;

' Fig. 12 is a detail section taken as indicated by line I2-I2 of Fig. 9;

Fig. 13 is a detail in longitudinal medial section showing a portion of the rst drier element;

Fig. 14 is a detail taken as indicated by line Il-M of Fig. 1;

Fig. A15 is a detail section on line I5--I5 o1' Fig. 4;

Figs. 16 and 17 are views similar to Figs. 4 and 5 but showing a modification.

In Fig. 1 the lm F is shown passing from a feed reel I5 rst over an elevator unit I6 of usual type, which may be considered simply as a frame with upper and lower rollers around which the film is threaded, and thence through a speed control device I'I. The latter may consist `of a series oi upper film rollers I8 and a series of lower illm rollers I9, the film being wound around said rollers and finallybeing brought oi of an upper roller I8 to be led to the flrst or developer unit 20 of the illm treating machine. Said lower rollers are tightly mounted on a drive shaft 2| (Fig. 2) on which is a friction disk 22 engaged on opposite sides by a pair of spring pressed

friction disks

23 and 24 spllned on a drive shaft 25 which is driven by an electric motor 26. Motor 26 and disksc23-and Mare mounted on a swinging arm 21 which is fast on a rock shaft 28 provided with an operating lever arm 29. As will be evident from the figures, the position of lever 29 determines the point of engagement of

friction disks

23 and 24 with driven friction disk 22, and therefore determines the speed ratio between motor 26 and film roller shaft 2I. 'I'hus the movable arm 29 controls the speed at which the film will be moved by rollers I9 and fed from speed control unit I1 into developer unit 20. Unit I1 may thus be considered as a film hold-backdevice, designed to feed the film into the developer at any predetermined rate of speed.

The film leaving speed control unit I1 passes in a' generally forward direction successively through developer unit 20, rinse tank 3l),` hypo unit 3|, wash unit 32, all of which are arranged in line, thence rises and passes in a rgenerally backward direction through drier 34 mounted directly over the wet unitsfand finally emerges near the film feed devices to be taken up by takeup reel 35.

Referring more particularly to Figs. l4 and 5, it will be seen that developer unit 28 comprises a relatively flat horizontal tank 40 having sides 4I, front and

rear ends

42 and 43, respectively, and a bottom 44. Bottom 44 comprises bottom portions 44a and 44b sloping downwardly from -ends 43 and 42towards the middle, for instance as shown in Fig. 4. The tank is shown supported above the floor by under framing46.

Mounted for rotation on tank side walls 4I adjacent tank'ends 42 and 43 are horizontal transverse

film roller shafts

48 and 49,respec tively, said shafts preferably being in the form of hollow tubes, as indicated in Fig. '1.

'I'he preferred rotatable mounting for the shaft ends is shown in detail in Fig. 'Il As there shown, hollow shaft 48 has' force fitted within its end a bearing plug 50 carrying a bearing insert element 5I which rotatably receives a spindle member 52 force fitted within a bushing 53 mounted as shown in wall 4I.

Rotatably mounted on

shafts

48 and 49 are individual independently rotatable film rollers 55. As here shown, these rollers 55, which may be of hard bakelite are mounted on sleeves 56 which are independently rotatable on shaft 48, sleeves 56 being in end to end engagement, as shown, and their inner surfaces being provided with lubricant receiving grooves 56a. Rollers 55 are spaced by hard rubber washers 56h. The ends of the roller shafts are screwthreaded, as at 48a, and screwthreaded on each end of the shaft and positioned adjacent the outer sleeve 56 is a nut 48h. 'I'his nut 48h-is not set up against the end of the sleeve so as to interfere withfree rotation thereof, but serves, in conjunction with a similar I without binding them against free rotation.

4Screwthreaded on the ends of the roller shafts and set up against positioning nuts 48h are hard rubber clamp nuts 48e. Preferably, the outside flange of each of the end rollers on the roller shaft is substantially increased in diameter, as indi-4 cated at 55a in Fig. '7, this provision serving to prevent the film from running olf the end rollers.

Mounted in the center of the tank, directly over 'the angle of the tank bottom, and parallel to

shafts

48 and 49, is a third shaft 51, which in the instance here shown is on a level a few inches below

shafts

48 and 49. and is journaledn spindles 51a mounted in side walls 4I as in the manner indicated in Fig. 6. It will be at once evident from Fig. 6 that the rotatable mounting of shaft 51 in the side walls of the tank is substantially like that described for the end mountings of

shafts

48 and 49. ,Y

' Central shaft 51 has rigidly mounted thereon a large film engaging drum or wheel 58.. As shown in Fig. 6, this drum is inthe form of end plates 59 rigidly mounted on shaft 51, and a drum cylinder 59a mounted at its two ends on outwardly facing annular shoulders 59h formed on end plates 59. Preferably, a covering 59c is stretched over the drum, being of some material suitable to give a good frictional driving engagement with the film-strip passing t'.ereover. This covering may be of a suitable fabric, though we find that a covering of soft rubber vulcanized over the drum possesses many advantages, and such a surface for the drum is preferred.

Fig.`6a shows a modified formof film driving drum which is of a squirrel-cage type, being made up of a pair of end disks 60 which are nonrotatably mounted on shaft 51, and a plurality of equally spaced and circularly arranged film engaging rods 6I connectingsaid disks. These rods are formed with a surface such as will give a frictional driving engagement with the surface of the film; for instance the rods may be formed of a composition such as bakelite, although the use of such material of courseis not limitative on the invention. The rods being formed into a circle, as indicated, act as a film driving wheel .or drum. The drum in this squirrel-cage form allows relatively free circulation of liquid longitudinally of the tank, and

may be of advantage in some instances for this reason. 5

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Asl shown in Fig. 4, the film rollers on

shafts

48 and 49 are spaced by a short distance above upper side of the film rollers onshafts 48 and 49, as indicated.

The film from speedcontrol unit I1 passes downwardly. at an angle and loops around an idler roller 65 mounted on one side wall of the tank, betweenwheel 58 and film roller shaft 48, andl is then carried backwardly to and around and up over a film roller 63, whichis rotatable on a shaft 64 located between idler roller 65 and the lm rollers on end shaft 48. In some instances the film strip may, instead of passing around roller 63,'vbe carrie lbackwardly to and around and up over the en lfilm roller on shaft 48, though the film strip is here shown as omitting to pass over said end roller. Whether the film strip is passed upwardly around film roller 63, or around the end roller on end shaft 48, it is then/ taken forwardly over the top side of drum 58 to the end film roller on shaft 49 at the" other end of the machine, thence around and under said roller, and from there rearwardly and under the lower side of drum 58, thence cn to pass time over the top side of film driving wheel or drum 58goes to a film roller 66a mounted on a shaft 66h and located between film roller shaft 49 andthe centrally located film drum 58, thence passing rearwardly to an idler roller 56 mounted between it and drum 58, and thence passing upwardly betweenl a pair of squeegee rollers 61 from which it is taken forwardly to rinse tank 30. It may here be noted that the film should be so arranged that its Celluloid side and not its emulsion side comes into contact with the film rollers 55 and driving drum 58. v

The film passes over sets of upper and lower rollers 69 and 10 in rinse tank 30, and thence passes on to hypo unit 3|. The hypo unit may be substantially similar to the developer unit 20. with the exception of perhaps being shorter in length since the hypo treatment does not require the film to be emersed for so long a time as is required in the developer.

From hypo unit the film passes between squeegee rollers 1| to the wash unit 32, which may also be generally similar to developer unit 20.

From Wash unit 32 the film passes between squeegee rollers 12 into drier 34. This drier will be explained in detail at a later point in the specification, it being sufficient hereto note that the drier takes the film continuously from the outgoing end of wash unit 32, and maintains a slight tension in the film leaving the wet section of the machine.V

The film strip is moved through the several units 20, 3| and 32 by yieldab1e.overdrive devices geared to the central film engaging drums 58, thesey devices being adapted to be slightly overdriven in order to keep the film strip sufficiently taut to give proper frictional driving engagement between said filmdrivlng vdrums and the film strip. Preferably, air driven turbines, as shown in section in Fig. v6, are used for this purpose.

As illustrated in Fig. 6, the end of shaft 51 on which wheel 58 is mounted carries a gear 80 just inside tank side wall 4|, and meshing with said gear atthe top is a drive pinion 8| on the inner end of a shaft 82 journalled in a mounting 83 carried by tank side wall 4|, in the arrangement clearly shown -in Fig. 6. On the outer end of shaft 82 is a turbine wheel 84'having usual blades 85, the wheel being driven by air from a nozzle 86 (see Fig. 4). The turbine Wheel is enclosed by a suitable turbine case 81.

As indicated in Fig. 1, each of units' 20, 3| and 32 is provided with such a turbine drive. Air under suitable pressure is supplied to the several turbines through a header 90' and branch pipes 9| having hand control valves 92.

As previously noted, the driving surface of film engaging drum 58 preferably supports and lifts the upper sides of the film loops somewhat between the rollers on

end shafts

48 and 49, and depresses the lower sides of the film loops between said rollers to follow an angular path substantially parallel to the two sloping sections 44a and 44h of thetank bottom. It will be remembered that With a given setting of control lever 29 of film speed control unit |1 the film will be fed into the developer'umt at some definite corresponding speed. The film strip threaded through units 20, 3| and 32 is then tautened and advanced by engagement of the upper and lower sides of the turbine driven drums 58 with the upper and lower sides of the film loops. In the embodiment of the invention shown in Fig. 6a, the individual rods of the wheels come successively into engagement with the runs of the film loops, both at the top and at the bottom, and by frictional engagement therewith move the film loops all together in a forward number of rods 8| on each wheel, so that when one rod is in full driving engagement with ,the film,

`say at the top, the film will be engaged by two of Y the rods at the bottom, and vice versa. By virtue of this alternation of the film loops are given additional OpDOrtunity to equalize tension.

Thus, the central large film driving drum being in driving engagement with a number of film convolutions, the tension exerted in each course of the film is very small, and the final effect is to give a very gentle frictional driving effect at each point of contact between the driving drum and the film strip. Moreover, because of the large radius of curvature of the film driving drum, and because of the fact that the film strip is not wrapped around the rotatable film driving member for of' contact, as in prior developing machines, tendency for breakage of the film in the machine is reduced to a minimum. 'I'he large drum secures but relatively small frictional grip on the film strip, and if the film strip is held back or stopped at the ingoing end, the drum simply slips on the film and continues to rotate, without unduly straining the film. The machine is also designed to equalize tension between the various film convolutions. It is for this purpose that the film rollers on end shafts 48 andv 49 are mounted for free, individual rotation. It will be evident that this individual freedom of rotation of each of said rollers allows the film strip to work in such a way as to equalize the tension throughout all its convolutions. 'I'he film strip of course must slip somewhat on the surface of the central driving drum as it is tensed up, or .during movement of slack through the machine, but the individual l rotatability of each of the film rollers allows the film strip to work through the machine in such a way that the film tension is equalized in all convolutions. We find as a matter of practice, however, that one further compensation is desirable to be made in order readily and easily to establish this complete equality of tension in all film loops passing over the drum. ',Ihe film entering the machine of course tends to elongate as ity passes on through the wet bath. This condition may promote a tendency to loosen the film slightly in the convolutions passing over the central portion of the driving drum. Such looseness in the last few convolutions passing over the drum does notoccur, due to the take-up tendency of the film driving means beyond. To compensate this tendency, the surface of the driving drum 58 is made slightly divergent from the ingoing side of the tank to a point somewhat past its mid point, and then slightly convergent from there to the outgoing side of the tank. For example, but without intention o f limiting the invention, a drum 26.5 in length may diverge from a diameter of 9.75l at its end adjacent the ingoing side of the tank to a diameter of 9.82 at a point two inches past its mid point, and may then taper from this point to a diameter of 9.77 at its end adjacent the outgoing side of the tank. If the surface of the drum is of rubber vulcanized in place, this taper may u be provided simply by grinding its surface to the dimensions required. These provisions having been made, the film convolutions therefore malntain a very accurate balance of tension between themselves, andthe driving tendency of the central driving drum is held exactly the same. on `al1 convolutions.

In Figs. 4, 5 and 15 the film strip is shown as threaded around

special film rollers

63 and 66a near the ingoing and outgoing ends of the developer tank, the film strip being left'ofl the` end rollers on

roller shafts

48 and 49 in each instance. In many instances, said

rollers

63 and 66a may be omitted, or disregarded, the film being threaded instead around the corresponding end rollers on 5

shafts

48 and 48. Howevenwhen it is desired to increase the drive effect of the central drum 58 on the film, the film is placed around these rollers, which being nearer the -drum than the rollers on the end shafts, cause the arc of contact of the corresponding film convolutions with the surface of the central driving drum to be increased, with consequent increased driving effect on those convolutions. In order that the'extent of this increase in drive effect may be adjustable, v rollers 63 andI 66a are mounted so as to be adjustably movable to different positions between center driving drum 58 and the end roller shafts. Thus, as shown in detail in Fig. 15, the shaft 64 of roller 63 is screwthreaded into a mounting assembly 220 slidable on a horizontal rail 22| extending between roller shaft 48 and guide roller 65. 'I'his rail 22| is mounted on the outer ends of pins 222 mounted in the side wall 4| of the tank, roller shaft mounting 228 having a hori- I zontal slot 223 passing said pins, as clearly shown in Fig. 15. Athumb screw 224 screwthreaded in the top member 228a of mounting assembly 228 is adapted to be set tightly against the top edge of rail 22| to clamp the roller mounting in adjusted position on the rail.

Figs. 16 and 17 show an alternative film threading arrangement which may be preferred. 'I'he machine shown in these figures is in most respect substantially the same as that of Figs. 4 and 5,

and corresponding parts of the two forms are identified by like numerals. In this instance, however, the film enters over idler roller 85, as before, but is then carried backwardly and up and around the end roller on shaftl 48. The film 40 is then taken forwardly over the top side of drum 58 to an adjustable film roller 63' located between the drum and shaft 49, passing around and under this roller to be taken rearwardly under the lower side of drum 58 to the second roller on end shaft 48. From this point the film goes forwardlyl over drum 58 to the second roller on forward end shaft 48, and so on inzthe previous manner to the other side of the tank. The film coming from the underside of the second from the last roller on drum 58 and then comes up and around an adjustable roller 88 mounted`between the drum and end shaft 48. From there thedilm goes for- -wardly over the `top side of drum 58 to the end 55 roller onforward shaft 48, and from the lower side of the latter it travels rearwardly to idler roller 56', under and around which it then passes before rising from the tank.

Rollers 83' and 88' are adjustable in position 60 on rails 23| and 232, respectively, similarly to the previously described embodiment, in order to vary the arcs of contact/ of the two convolutionsycontrolled by said rollers to vary the driving e'ect of the drum on said convolutions. Rail 23| is pref- 65 erably so located vthat the top side of roller 83 is' substantially in the plane of the film strands passing from the top side of drum58 to the film rollers on shaft 48, while rail 232 is preferably so located that "the bottom side of roller 63 is 7n substantially in the plane of the film strands passing from the bottom side of drum 58 to the film rollers on shaft 48. Thus adjustment of the position of rollers 83' .and88l' longitudinally on rails 23|4 and 232 ad- 75 justs the arc of contact with the of the two individual film rollers on the two end shafts of.

sides of the rollers on shaft 48 (see Fig. 5).

film convolutions controlled by said rollers, and

in this manner regulates the total drive effect of the drum on the film passing through the unit.

In the particular arrangement here shown the the developer are mounted directly opposite one another, rather than being staggered, and the film strip is carried straight forwardly from the top sides of the rollers on shaft 48`to the top sides of the rollers on shaft 49, but runs at a slight 10 angle to the upper film runs in passing from the lower sides of the rollers on shaft 49 to thelower It is found that the lower angular runs of the film strip tend to work laterally a fraction of an inch l5 on the driving wheel during operation, so that the edge of the film strip rubs against any usual film guide means that might be provided adjacent the driving wheel, such for instance as flanges on the wheel itself, or guide rollers or wire loops 2O mounted adjacent said wheel. Accordingly, we provide a`fllm guide means directly before the driving wheel which is freely shiftable in a lateral direction to accommodate this tendency of the film to work over slightly on the wheel. As 25 shown in Figs. 4 and 4a, there is provided just before the driving wheel a bar 13 having individual film guides in the form of wire loops 14, which are adapted to take and space the successive stretches of the film strip passing under the 30 driving wheel. This bar extends transversely of the tank and its two ends are notched at 'I5 and slidably mounted on pins 16, as clearly indicated in the figures. It will be evident that the guide bar therefore floats laterally, and accommodates 35 its position to that naturally taken by the film on the driving wheel.

The air supply to each turbine wheel is adjusted by means of its individual control valve 92 in such a manner as to tend to drive the film 40 at a speed just slightly in excess of that permitted by the constant speed film feed device. The turbines are adjusted to give but very slight excess force, so that the film will be sufiiciently taut^ that the film driving drums 58 will not slip on 45 the film, but still will not be unduly strained by the yielding tendency of the air driven turbines to over-drive. Excess slack is prevented from 1 accumulating in the machine when the film becomes wet and elongated by a friction or yieldable over-drive take-out device |08 at the outgoing end of the drier, as hereinafter to be described in more detail, this take-out device moving said slack forwardly through the developer, hypo and wash units, and then through the drier. `Itis in practice comparatively simple to adjustthe turbines tomove the film through the several units in succession at constant speedand with the film sufficiently taut that no substantial slippage of the driving wheels on the film occurs, but still without tensing the film strip F'sufficiently to elongate it permanently.

Figs. 1, 4 and 5 illustrate how the liquid is supplied to and flows through each of the several wet units of the machine. A developer solution supply pipe isshown at 8 in Fig. '1, said pipe ||8 dividing into branches supplying a set of feeder pipes |2 extending through tank side walls 4| and transversely across the tank bottom. These feeder pipes ||2 are provided with jets ||3 70 which are arranged to discharge liquid along the sloping sections of the tank bottom in the direction of movement of the lower runs of the film convolutions. We may also provide, if desired, a set of upper feeder pipes ||2a having jets ||3a 75 arranged to discharge liquid above and in the direction of movement of the upper runs of the film. These upper feeders may be supplied by branch pipes Illa leading from pipes ||I. The liquid continuously 4discharges from the tank by flowing over an over-flow edge at the rear end of the tank, said edge being at a level just above the upper runs of the film convolutions. For instance, though'without implying any limitation on the invention, the liquid level as determined by over-flow edge |20 may be in the neighborhood of say three-quarters of an inch above the upper side of the film driving wheel 58 'I'he liquid over-flowing said edge |20 is t'aken within a tank |2I discharging 'into a pipe |22.

Movementl of the film through vthe machine is accompanied by a characteristic general circulation of the developer liquid toward the forward end of the tank (to the left in Fig. 4) along the tank bottom and toward the rearward end of the tank (to the right in Fig. 4) at the surface, to discharge'finally over edge |20. This characteristic circulation is induced first by the liquid being discharged from jets I I3 directly along the bottom in the direction of the forward end ofthe tank,4 from jets ||3a in a reverse direction in the upper portion of the tank, and next'by the skin frictional drag on the liquid of the moving strands of film in both the lower and upper runs of the lm convolutions. The liquid thus flows in a lower level moving along the bottom with the lm and up the upwardly inclined section 44h of the tank bottom to tank end 42, where it rises and turns backwardly on itself to form a surface layer of liquid moving toward the rear end of the tank along with the film strands comprising the upper runs of the lm convolutions, the liquid thus moving against its original direction aided by the skin frictional drag of the upper film strands, together with the liquid discharged from jets II3-a and the discharge of liquid over the rear end overflow edge |20. ,f There is of course a general tendency for the liquid discharged from lower jets I |3 to rise as it flows toward tank end 42, but this is not suflicient to avoid the general and characteristic flow in one direction with the lower nlm runs and in the opposite direction with thef upper film runs. This gradual rise of the developer is of advantage in that fresh developer is thereby constantly brought into contact with the lm. It may be noted the squirrel cage type film driving wheel will have some effect in causing a tendency for vertical movement of the developer solution. Thus there is a layer of liquid moving along with the film toward the left in the bottom of the tank, as viewed in Fig. 4,

` and another layer of liquid at thesurface movhaving branch pipes |26 supplying feedersI which introduce the water to the Wash tank.

We proceed now to a descriptionv of the drier unit. As shown best in Figs. 1, 8, 9 and 13, drier l34 comprises a long closed conduit |30, preferably rectangular in cross section, mounted immediately above the alined developer, hypo and wash units, as shown. Said conduit is made up of top and bottom wallsv |3| and |32, respectively,

and side walls |33. The side walls mayhave suitable doors, not shown, for the purpose of gaining access to the interior of the drier. The conduit is supported by means of vertical members |35 mounted on the sides of the developer, hypo and Wash tanks, as indicated in Fig. 1.

The lm srip coming from between vsqueegee rollers '|2 at the outgoing end of the wet section of the machine passes upwardly at an angle, as shown in Fig. 1, and enters the drier through an aperture |36 in the bottom of the conduit (see Fig. 13) The lm leaves the wash tank emulsion side up, and is given a half twist between the wash tank and the drier conduit so that the emulsion side of the film will be away from the roller surfaces in the drier. The film upon entering the drier passes upwardly and around end film roller |45 on transverse shaft |40.

v'I'hedrier is divided into a number of successive film carrying sections, such as 'A, B, C, and D, a portion of section A being shown in Fig. 13, and section D being shown in greater detail in Figs. 8 and 9. Within each of said sections, which are in general similar to each other, the film strip passes through a set of parallel convolutions which extend longitudinally of the conduit, as shown best in Figs. 8 and 9. The section D of the drier through which the film passes last is shown best in the drawings (Figs. 8. and 9), and will be described in detail as typical of the several sections. Considering section D, therefore, we show mounted in the side walls |33' of the conduit a pair of longitudinally spaced film roller shafts |40 and |4I, and midway between said shafts and preferably on the same level a third shaft |42.

Freely and rotatably mounted on the end shafts and |4I of this drier section are individual film rollers (see Fig. 10), and non-rotatably mounted on center shaft |42 is a film driving drum |46, which in the present illustrative ernbodixnent is of a diameter substantially siX times that of the lm rollers on the end shafts. diameter of this drum is of course susceptible to considerable variation, the diameter indicated not being limitative on the invention in its broader aspects.

As is shown in Figs. 8 and 11, drum |46 is made up of end plates |48 rigidly mounted on shaft |42, and a drum cylinder |49 mounted at its two ends on annular flanges |50 extending inwardly from plates |48. Preferably, a fabric covering |5| is stretched over the exterior of cylinder |49, and is fastened tightly in place between the ends of the cylinder and the previously mentioned flanges |50, as clearly shown in Fig. 11. This fabric covering is of a nature suitable to give a good frictional driving engagement with the drying lm strip. y

Drum shaft I 42 has on its outer end, outside side wall |33, a wheel which is drivingly engaged on its top side by a friction wheel |56 which is mounted on the end of a spindle 51 journaled in a turbine wheel mounting box |58, the latter being secured to the side of the'drier case as indicated in Fig. 11. Friction Wheel |56 is preferably formed of cork, which is found to have great durability, as well as to permit slippage should the turbine drive of said wheel be too strong. On the other end of shaft |51 is a gear |60 frictionally engaged by a'geal' '5| mounted on turbine wheel shaft |62; vShaft |62 has 011 its outer end an air turbine |63, provided with blades The turbine wheel is driven from air discharged by a nozzle |65 which is positioned to The direct an air current against blades |64, the air current being controlled by a hand valve |61 in supply pipe |68. 'I'he turbine wheel is enclose by a casing |66, as indicated.

The film strip coming from the upper side of the center driving drumof the preceding section of the drier, rst engages the top side of the driving drum |46, thence passes downwardly at a small angle to its original direction and loops around the end roller on end shaft |4|, from there passes under the lower side of drum |46 and so on back to a roller on shaft |40, looping upwardly around said roller and passing forwardly again over the top side of drum |46, and

so on in successive convolutions to the other side of the conduit. Each horizontally arranged lm convolution is thus supported top and bottom by the centrally located driving drum. The described arrival of the film at drier section D is illustrative of sections B, C, and D, while it has previously been described how the film reaches the end film roller of first section A (Fig. 13).

It is here to' be noted that the film strip must be threaded on the sets of rollers on the several drier sections with its emulsion side out. This is of great importance, first, in that the emulsion is mutilated if the emulsion side of the film is allowed to come into contact with the surface of the rollers, and second, in that it is highly desirable that the emulsion side of the film be on the outer side of the film convolutions where the drying effect of vthe heated air stream is much the greater.

The drier has a transversely oating lm guide not requiring the floating film' guide.) The ends of bar |69 are slotted, as at |69b, and slide on guide pins |690, as indicated. The lm guide accordingly is capable of accommodating itself to the position taken by the film as the film tends to work laterally on the driving drum and thereby avoids rubbing of the film edges on the guide wires.

Preferably, sets of fixed lm guide loops |59 and |59a are mounted just before the rollers on shafts |40 and |4|, respectively.

Polishing rollers, indicated at |6| in Fig. ,1, are preferably mounted between the film rollers and central driving drum in drier section A, these rollers, which are covered with chamois or other suitable material, polishing the celluloid surface of the film passing between the'film rollers and the center driving drum.

Y preferably of cork, to give a frictional drive which is durable and also which will allow slippage if the turbine shaft is too strongly driven. A turbine wheel |94 having blades |95 is mounted on shaft |93, and is driven by air from a nozzle I 96. The air from this nozzle is adjusted'by a hand Valve |91 to give the turbinejust sufficient drive that the reel 35 on shaft |90 will be slightly over driven, that is, will exerta slight tension on the film coming from the ejector of the drier.

It has been described how the turbines of the wet section of the machine have a slight' overdrive tendency, so as to move any slack forwardly through the machine. The drier then takes the film, and the Adrier turbines are adjusted so that the rotating film driving drums 46, which support and are in frictional engagement with the sets of film convolutions in the drier, also have a slight tendency to over-drive the film through the drier. These various over-drives, of course, are in no instance suflicient to give a permanent elongation to the film, but are only sufficient to take up the slack and maintain a suitable tension in the film. Inasmuch as each driving wheel or drum is in driving engagement with a number of film convolutions, the tension exerted in each course of the film due to this over-drive tendency is very small, and the final result is to give a very gentle driving effect at each point of contact between the driving drum and the lm strip. The film ejector at |10, |1| and the final take-out de- ViCe |00 then remove the film from the drier and reel it up, the take-out device also being adjusted with a slight over-drive tendency so as to draw the film from the drier and prevent slack therein. Thus the over-all tendency of the machine as described is to move slack forwardly through both the wet section and the drier and to take such slack up at the nal take-up reel 35. Of course, a

large amount of slack which is due to film elongation in the wet section is taken up by natural film shrinkage in the drier, but any excess slack is moved forwardly through the machine and is taken up by final take-out device I 00.

The lm roller and driving arrangement of the drier is designed with the particular view of equalizing tension between the various film convolutions. It is for this purpose that the film rollers |45 on the end shafts of each drier section are mounted for free, individual rotation. It will be evident that this individual freedom of rotation of each of saidrollers allows the lm strip to work in such a way .as to equalize the tension throughout all its convolutions. The nlm strip of course must slip somewhat on the surface of the central driving drum as it is tensed up, or during movement of slack through the machine, but the individual rotatability of each of the film rollers y volutions therefore maintain a very accurate balance of tension between themselves, and the driving tendency of the central driving drum is held exactly the same on all film convolutions.

Cil

It has been described how the fllm is polished by the rollers I8! in the drier. The film is also polished in slipping slightly on the driving drums.

It will be evident that such slippage will depend upon the tension placed on the film, which may be controlled by regulating the hold-back on the film at the beginning end of the machine, or by regulating the force exerted by the final take-out device.

A current of heated air is delivered to the film outlet end of the drier conduit through an air inlet conduit 200. This current of heated air passes over the successive sections of the drier comprised by theseveral sets of longitudinally arranged film convolutions, and is finally discharged through air outlet conduit 20|. It will be noted that the air blast is thusvin a direction contrary tothe direction of film progression through the conduit.` Accordingly, the heated air upon introduction to the conduit comes first into contact with that portion of the film which has longest been in the drier conduit and is consequently already substantially dry, and then passes on through the successive sections of the drier wherein the film is in progressively wetter condition. The air of course becomes more and more laden with moisture as it passes from section to section,

with the result that its drying effect is lessened asit passes through the conduit The film in the last section D, however, is always subjected to the in-v fluence of the dry incoming air. This arrange'- ment is conducive to most effective and rapid drying of the film.

It is to be noted that the sets of parallel, elon gated film convolutions of the drier are arranged longitudinally of the heated-air conduit, or in otherI words, parallel to the direction of heated air flow. It will also be remembered that the film strip passes over the successive sets of film convolutions emulsion side out. These features of design and arrangement are productivefof greatly increased efficiency of drying, as may'be appreciated from the considerations following. It is of course well known that it is the emulsion face of the Celluloid film strip that requires time for drying, the emulsion beingvin a very sticky and plastic state when wet, and requiring a much longer time to dry than does the celluloid. In our drier design, the film strip is arranged throughout the sets of elongated convolutions in each of the successive drier sections with its emulsion side out, that is, presented to the heated air stream that is continuously passed through the drier conduit. Within the lm convolutions the air is relatively quiet, and drying would be relatively slow and ineffective; however,as has been said, the Celluloid dries rapidly, and the inner side of the film strip nevertheles-s is completely dry before the film leaves the drier. Outside and along the outer sticky surfaces of the longitudinal runs of the fllm convolutions, the lheated air stream flows rapidly along in a continuous stream, licking the emulsion surfaces of the film strands and rapidly removing the moisture therefrom as it passes. This air stream is not broken up and caused to flow in various cross and counter directions,r but is always substantiallyparallel to the longitudinal runs of the lm in the conduit; moreover, very nearly one hundred percent of the film within the convolutions of the drier runs in a longitudinal direction, parallel with the air stream -and with its of the features here spoken of, the drying time is reduced very materially below what is usual in prior driers of standard types, and consequently the total film footage required within the drier, and therefore the size of the drier itself, are correspondingly reduced.

We have illustrated our invention in a form in which the Yfilm strip is fed into the wet section at constant (predetermined) speed, and is removed from the drier by a slightly over-driven take-out device. It will be understood that-the film driving arrangements within the wet and dry sections of the machine are also applicable to the reverse i design, in which the film is removed from the drier at constant speed by a constantly driven take-up reel, and is retarded at the ingoing end of the wet section by a friction hold-back device,

of conventional type. Since the latter film feed and take-out arrangement is well known to those skilled in the art, it need not here be further described. It should further be understood thatwhile we have for illustrative purposes shown and described one specific embodiment of the broad invention, that invention is not to be limited in its broader aspects to the details of the illustrative embodiment, but only as may fairly be construed from the following claims.

We claim:

1. In a film handling apparatus, the combination of two sets of film rollers mounted on parallel axes and adapted to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum extending through said filmV convolutions between said two set of rollers and frictionally engaging the inner surfaces of film strands passing between said sets of film rollers to advance the film, and means for driving said drum.

2. In film handling apparatus, the combination of two sets of film rollers mounted on parallel axes and adapted to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum of diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said two sets of rollers and frictionally engaging the inner surfaces of the film strands passing in both directions between said sets of film rollers to advance the film, and means for driving said drum.

3. In film handling apparatus, the combination of 'two parallel rotatable film roller shafts,

a set of film ,rollers mounted on each of said shafts, said sets of film rollers being arranged to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum extending through said film convolutions between said sets of rollers and arranged for frictional driving engagement with the film moving in both directions between said sets of rollers, and means for driving said drum.

4. In film handling apparatus, the combination of two parallel rotatable film roller shafts, a set of filmrollers mounted on each of said shafts, said sets of film rollers being arranged to have a film strip looped and moved therearound in e1on-1 gated adjacent convolutions, a rotatable film driving drum of a diameter greater than the diameter of the film rollers, said drum extending through said. lm convolutions between said sets of rollers and arranged for frictional driving engagement with the film moving in both directions between said sets of rollers, and means for driving said drum- Cil 5. In film handling apparatus, the combination ofA two parallel film roller shafts, a set of film rollers independently rotatably mounted on each of said shafts, said sets of film rollers being arranged to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film drivingdrum extending through said film convolutions between said sets of rollers and arranged for frictional driving engagement with the film moving in both directions between saidsets of rollers, and means for driving said drum. l y f 6. In film handling apparatus, the combination of two parallel film roller shafts, a set of film rollers independently rotatably mounted on each of said shafts, said sets of film rollers being arranged to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum of a diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said sets of rollers and arranged for frictional driving engagement with the film moving in both directions between said sets of rollers, and means for driving said drum. e

7. In film handling apparatus, the combination of two parallel rotatable film roller shafts, a set of film rollers individuallyrotatably mounted on each of said shafts, said sets of film rollers being arranged to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum extending through said filrnconvolutions between said sets of rollers and arranged for frictional drivging engagement with the film moving in both directions between said sets of for driving said drum.

8. In film handling apparatus, the combination of two parallel lrotatable filmroller shafts, a set of film rollers independently rotatably mounted on each of said shafts, 'said sets of film rollers being -arranged to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum of diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said sets of rollers and arranged for frictional driving engagement with the film moving in both directions between said sets of rollers, and means for driving said drum.

9. In film handling apparatus, the combination of a supportingmeans, sets of film rollers mounted on said supporting means on horizontally spaced parallel horizontal axes, said rollers aruranged to have a film' strip looped and moved therearound in elongated adjacent convolutions,

rollers, and means Y arrotatable film driving drum of diameter greater said two sets of rollers and frictionally engaging both directions between said s ets of film rollers the inner surfaces of the nlm strands passing in to advance the film, and a nlm guide device embodying a plurality of loop members adapted to receive and guide the film runs at a position adjacent a side of the rotatable film driving drum, and a single support for said loop members mountedfor free floating movement in a direction parallel to the axis of the film .driving drum.

11. In film handling apparatus, thel combination of two sets of film rollers mounted on parallel axes andadapted to have a film strip looped and moved therearound in elongated adja- -cent convolutions, a rotatable film driving drum of diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said two sets of rollers and frictionally engaging the inner surfaces of the film strands passing in both directions between said sets of film rollers to advance the film, and a film guide device embodying a plurality of loop members adapted to receive and guide the film runs at a position adjacent a side of the rotatable film driving drum, and a single support for said loop. members mounted for free floating movement in a direction parallel to the axis of the film driving drum.

12. In film handling apparatus, the combination of two sets of film rollers mounted on parallel axes and adapted to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable film driving drum of diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said. two sets of rollers and frictionally engagingv the inner surfaces of the film strands passing in both directions between said sets of film rollers to advance the film, and a film roller for the loop end of one of the film convolutions adjustable toward and from the film.

driving drum to regulate the arc of contact of that 'film convolution with the drum.

13. In film handling apparatus, the combination of two sets of film rollers mounted on parallel axes and adapted to have a film strip looped and moved therearound in elongated adjacent convolutions, a rotatable lm driving drum of diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said two sets of rollers and frictionally engaging the inner surfaces of the film strands passing in both directions between said sets of film rollers to advance the film, and film rollers for'the loop ends of two j selected film convolutions adjustable toward and from the film driving drum to regulate the arcs of contact of 'those film convolutions with the drum.

14. In film lhandling apparatus, the combination of two sets nof film rollers mounted on parallel axes and adapted to have a film strip looped and moved therearound in elongated adjacentconvolutionaarotatable film driving drum of diameter greater than the diameter of the film rollers, said drum extending through said film convolutions between said two sets of rollers and frictionally engaging the'inner surfaces of the film strands passing in both directions between said sets of filmrollers to advance the lm, and film rollers for the loop ends vof the first and last film convolutions adjustable toward and lfrom the film driving drumto regulate the arcs of contact of those film convolutionspwith the drum. f

HARRIS N. ENSIGN." I-IARRY A. HANSON.