US2281094A - Agitating device for photographic developing baths - Google Patents

Description

April 23, l942- c. c. CHAMBERS 2,281,094

AGITATING DEVICE FOR PHOTOGRAPHIC DEVELOPING BATHS Filed March 26, 1940 2 Sheets-Sheet l l l l I Y mm z 54' f f 19 19# 2 s a# '22 ,y s Z 4r :auf gw April 28, 1942 c. c. CHAMBERS 2,281,094

AGITATING DEVICE FOR PHOTOGRAPHIC DEVELOPING BATHS I Filed March 26, 1940 2 Sheets-Sheet 2 y If" l I 955733 9 I f l f/ hf f l 1952@ wf .4 /ZZ ze* f 132V 252 j @gt M f m f in w f 14 f f6 f 4 f6 26 f Patented Apr. 28, 1942 AGITATING DEVICE FOR PHOTOGRAPIIIC DEVELOPING BATES Carl C. Chambers, Lansdowne, Pa.,

l assign'or to Edward Stern Company, Incorporated, Philadelphia, Pa.,

a corporation of Pennsylvania Application March 26, 1940, Serial No. 326,012

19 Claims.

The present invention relates to the treatment of photographic films and plates in developing and fixing baths with particular reference to agitation of baths.

A P urpose of the invention is to eliminate the need for cut-and-try operations in the developing of plates and films so that the plates and films may be developed uniformly, reliably and correctly by merely subjecting them to the developing process for a predetermined period-of time and preferably as an automatic operation.

A further purpose is to provide a reciprocating agitator of a developing solution with a freedom to accommodate its position to flow reversals of the solution at the end of each stroke of a reciprocator operating the agitator, thereby preventing surgings of the treating solution against the developing plate or nlm of the character which might deflect the plate or lm into the path of the agitator and cause scraping or scratching of the plate or film.

A further purpose is, at the end of each stroke, te damp surgings in one direction before creating them in the reverse direction.

A further purpose is to avoid sweeping the film or plate frontally back `and forth just after the stroke reversals ofthe agitator.

A further purpose is to avoid or greatly lessen unevexlness of agitation at the surface of the developing film or plate and to avoid or greatly lessen standing waves in the solution.

A further purpose is to move a photographic processing bath content across the surface of the film being `processed with a component of flow directed transversely toward the film surface in each movement.

Further purposes will appear in the specificanon and in the claims.

My invention relates both to a new process of agitation of the developingsolution for better andmore uniform developing conditions at the developing surface of the film or plate and to the agitator for accomplishing my new process.

I have elected to illustrate my invention in a few only of its many forms, selecting forms, however, that are practical and eilicient in operation taneously upon two films or plates respectively on opposite sides of the agitator instead of a single film or plate on one side only of the agitator.

Figures 2 and 2a are diagrammatic elevations illustrating horizontal reciprocation of a horizontally yieldable agitator element horizontally across the face of a vertical film or plate, the

and which well illustrate the principles involved.

Figures 1, 1a and 1b show vertical reciprocations of` an agitator element vertically across the vertical face of a film or plate, the views being diagrammatic elevations, showing, in great exaggeration, the intended range of yielding of the agitator with respect to its reciprocator and the views being intended to illustrate some `respectively diferent types of yieldable agitator elements adaptedto the present invention.

Figures 1c, 1d and 1e are views corresponding generally to Figures 1, 1a and 1b respectively, except that in each case the yieldable agitator element has been modified for operation simulagitator operating respectively on a single film or plate and ontwo films or plates, and in each case intended for any suitable horizontally yieldable agitator, but showing agitator elements generally like those in Figures 1 and 1c respectively, suitably modified for horizontal instead of vertical reciprocation.

Figures 3 and 3a are horizontal sections respectively of Figures 1 and 1c in accord with the section lines 3 3 and :ia- 3a thereof taken in the direction of the arrows.

Figures 4 and 4a are horizontal sections respectively of Figures 2 and 2a upon the section lines 4 4 and 4a-4a thereof in the direction of the arrows.

Figures 5 and 5a are enlarged fragments of Figures 3 and 8a,` but with the agitator element in each case in its midposition.

Figures 6 and 6a are respectively a bottom plan View of a portion of Figure 2 and a top plan view of a portion of Figure 2a, in each case modied to show the agitator" element in its midposition.

Figures 7 and 7a are sections respectively of Figures 5 and 5a upon the lines 1-1 and la-'la thereof in the direction of the arrows.

Figures 8 and 8a are front elevations respectively of Figures 6 and 6a.

Figures 9 and 10 are respectively front and side elevations showing a somewhat different vtype of agitator mount from that in the intended conventional showing of Figure 1.

Figuresll and 12 are front and bottom views of agitator structure, which illustrates that more than one agitator element may be used, spaced from one another on a common reciprocator for relatively large films without need for a correspondingly large reciprocation stroke.

Figures 13 and 14 are front views of typical frames to support respectively a photo lm and a photo plate when developing.

Figure 15 is a top plan of Figure 14.

Like numerals refer to like parts in all figures.

Describing in illustration and not in limitation and referring to the drawings:

In the past agitator elements have been reciprocated in front of and across developing photo# graphic films and plates submerged in the dejust after each reversal in the strokev of the agitator.

My studies indicate that in the past there have been unpredictable fluctuant conditions :at the plate or film portions near the agitator at the moments immediately following stroke reversals, with suddent condition changes that have brought unevenness in the action of the developer upon the film or plate and with often to-a'nd-fro movements of the developing plate or film such that there has sometimes been a scratching of the developing face of the plate or film against the agitator element.

Particularly in the photo-engraving and photooffset processes, where very large plates and films are employed, and lack of `uniformity of development is likely to be serious when in smaller work it could be ignored, these previous diiilculties have completely interfered with automatic processing of films and plates. As a result, it is so far as I known universal to process plates and films for use in photo-engraving and photo-offset printing by the trial and error method under observation of the operator, who determines in each instance when the plate is sufficiently processed.

In the present invention I have corrected these former faults of automatic agitation -by making the agitator element free to accommodate its position after each reversal to the existing liquid pressure conditions on opposite sides of the agitator element. In effect, at the end of each stroke, I damp the surgings in one direction before creating surgings in the reverse direction, and I do this by providing lost motion between the agitator and the reciprocator carrying the agitator. Stated differently, IA make the agitator (preferably right at the blade) yieldable at the beginning of` each stroke in a direction counter to that of the beginning stroke and yieldable to the greater frontal liquid pressure to avoid a momentary local turbulence that otherwise would bepresent, with the unhappy results explained above.

A further feature of considerable importance in the present invention is that in the preferable embodiments of the invention, for example those of Figures 1, la, 1c, and 1d, there is a component of liquid flow directed transversely toward the surface of the film or plate during each back and forth movement of the agitator. This component effectively projects the `liquid violently graphic films and plates for use in producing I plates in the photo-offset process, particularly the against all parts of the plate and against all parts equally. l

Thus it will be evident that I obtain back and forth movement of the bath content across the surface of the photographic film or` plate being processed, with yielding reversal of the direction of flow of the bath content at the end of each back and forth movement and preferably also with a component offlow directed transversely against the film surface in each back and forth movement. The feature "of producing yielding of the flow impulse at the end of each back and forth stroke in a direction counter to the next stroke, and the feature of causing flow transversely toward the film surface during each stroke, I regard as highly important.

0f course, it will be understood that the angle of inclination of the agitator blade toward the film surface may be variant to produce the desired transversely directed flow component, and, in fact, the various figures illustrate variant angles of inclination for the different agitators.

The effect of application of the principles of 'the present invention to development of photofine screen photo-sensitive gelatine process, has been very pronounced.

By the agitation process of the present invention, it is possible to process entirely on a time basis, producing uniform development over large films and plates and reproduceable for different films and plates, without the necessity of inspection of the films and plates during processing to determine the end point of development. This result has, to the best of my knowledge, never beforebeen attained.

In Figure l a photographic film or plate I9 is submerged in developer solution 20 within a con' tainer 2 I, the film or plate I9 being supported in any suitable way, vertical and near one side 22 of the container 2I.

An agitator 23 adapted vertically to reciprocate in front of the plate I9 is carried by a reciprocator 24 that is shown asa downward extension from a vertically reciprocatory head 25. The exposed surface of the film or plate faces toward the agitator. y

The stroke of the agitator at its edge 26 presented toward' the plate I9 ispreferably somewhat greater than the vertical extension of the plate, with the agitator on its highest position thus somewhat higher than the top of the film or plate I9 and in its lowest position somewhat lower than the -bottom of the film or plate I9. The depth of immersion of the agitator in its high position preferably should be great enough to avoid material surface waves and turbulence at the end of up strokes-as surface turbulence of the developing solution seems to result in a more rapid deterioration of the developer solution than is otherwise present.

The agitator 23 is intended to be adapted to yield with respect to the reciprocator at the beginning of each stroke in a direction counter to that of the beginning stroke and to an extent great enough to relieve a momentary turbu lence and mounting of the liquid pressure ahead of the agitator 23 at the start of the new stroke. Such turbulence and mounting liquid pressure in the past have brought both fluctuant lmovement of the film or plate I 9 and an unevenness of development, as between the upper and lower portions of the film or plate receiving the turbulence at the beginning of the strokes and the intermediate portions of the film or plate.

The agitator 23 preferably should vbe somewhat longer than the horizontal extension (heren ment of any suitable hanger adapted to support the film or plate I9.

The description thus far is intended to apply to each of Figures 1, 1a land 1b, and also to each of Figures 1c, 1d and 1e except that in the latter figures two films or plates are developing at once, with the agitator operating at the two films or plates, one at each of vopposite sides of the container. while in each of the former Figlures `1, 1a and 1b a single film or plate is developing.

' In each of Figures 1, 1a and 1b the film or l 2,281,094. plate I! isncar one of the opposite wallsoi' the container. with the reciprocator 24 near the other wall. supporting the agitator 23 near one side: and in each of Figures 1c, 1d and le the reciprocator 24' supports the double acting agitator 23' near the middle.

'I'he description also appliesto Figures 2 and 2a except that in the latter figures the agitation is horizontal instead of vertical. .The agitator 232, being vertical instead of horizontal. is carried on a vertical rod 242, extending downward from a reciprocator head intended to reciprocate horizontally in a direction transverse to the plane of the paper.

Figures 1, `1a and 1b illustrate respectively different types oi agitator elements 23, each mounted on a vertical reciprocator 24 and at the beginning of each stroke adapted to yield` somewhat in direction counter to that of the new stroke.

In Figure 1, as seen in Figures 3, 5, and 'Lythe agitator 23 comprises a light preferably metallic sheet recessed at 28 to receive the tubular reciprocator 24 and formed to pivot on a rod 29 through the agitator 23.

'I'he sheet is additionally cut away somewhat at in front of the tubular reciprocator 24 to provide the agitator 23 with a short range of free movement on its pivot 29, the agitator 23 stopping when moved up or down, by its engagement at 29 with the reciprocator 24.

In Figures lc, 3a, and 5a the double agitator 23' consists of hinge members of light sheet material, hinging on a common rod or pintle 29 through the tubular agitator 24'.

In each of Figures 1a and 1d the agitator 23 or 23 comprises a light resilient sheet fastened at one side or middle respectively tothe reciprocator 24 or 24 that is intended to be shown as a sheet optionally of the same length as the agitator. The weight and dimensions of the agltator 23 or 23 are so selected that the sheet will yield to relieve pressure differences above and below the sheet, differences that would be significant at the beginning of each stroke were it not that the agitator 23 or 23 relieves them by yielding in direction counter to that of the new stroke. In this form, the agitator may consist of a very light metallic sheet, or soft rubber or synthetic rubber, for example.

In `Figures 1b and lathe agitator 23 or 23 is in each case intended to be a rectangular plate or sheet having a lost motion slidesupport at the lower end of the reciprocator 24 or 24. Each reciprocator 24 or 24' comprises a pair of rods, spaced from one another in a direction transverse to the plane of the paper, so that one rod only is seen in the drawings. A two rod lost motion support of the agitator 23 or 23', as distinguished from a one rod support thereof, prevents angular movement of the agitator, keeping it with its outer edge 26 or outer edges 26 parallel to the fllm or plate or films or plates.

In the structure of Figures 2, 4, 6, and 8 the vertical rod 242 fromvthe reciprocator head 25 loo ely pivots the agitator 232. 'I'he agitator 232 is sh wn as a sheet having one side wrapping the rod 242 above the right bend 3| at the bottom end of the rod. The sheet wrapping is upwardly recessed at 282 to receivethe rod bend 3|, the bend 3| limiting angular movement of the agitator by its engagements with the rod, on one side by the fiat of the sheet and on the other side by the cut edge of the recess.

In Figures 2a, 4a, 6a, and 8a the vertical rod 3 24I down from the horizontal reciprocatory head 25' forms 'in ell'ect a pintle pin for the vertical sheet agitators 232 and the angular movements of the agitators are limited by a cap 32 on the lower end oi' the rod. The cap 32 is recessed at 33 and 33 to receive the lower' edges oi' the hinging sheets. the edges at I3 or Il" on opposite sides ol each sheet 232 limiting the hinge movement of the` sheet.

: tened at 44 to a cross arm The reciprocator 24 or 2 intended to be indicated conventionally inA ures 1 and lc, but shown as a single tubularunember mounting the agitator or asitators at t e middle, may be, in fact, for example, parallel arms 243 at opposite ends of the agitator (Figures 9 and 10).

As illustrated in Figures 9 and 10 the reciprocator 243 comprises an inverted U bent strip, Iastened at 35 to the vertically reciprocatory head 25 and with the arms 243 at their lower ends pivoting opposite ends of the agitator 23.

The ends of the agitator 23 are shown cut away to receive the reciprocator arms and to provide edges at 36 to limit the angular movement of the l and downward engageagitator by their upward ments with the reciprocator arms.

Figures 11 and 12 illustrate that the reciprocator 24 may carry more than one agitator 23. As illustrated similar upper are mounted on a common 24 by pivot pins 29 and for greater strength the ends pf each of the pivot pins are pivotally supported by a horizontal bracket 31 intended to be welded at 38 to the back of the reciprocator. The use of more than one agitator 23 along the agitator stroke is sometimes desirable in that it lessens the requisite length of stroka/ Figure 13 illustrates a conventional frame support for a photographic film, with the lm 9 shown in dot-and-dash outline.

The film I9 is held at the upper and lower corners by clips 40 and 4|, the bottom clips 4| being welded at 42 to the bottom of the frame while the upper clips 40 are carried by the ends of a spring 43 that is welded or otherwise fas- 45 of the framework. The upwardly extending side arms 46 are rigidly fastened to an intermediate portion of the top member 21 which is long enough to san the end tubular reciprocator Walls of the container 2|. Downw rd lugs 41 from the top member are positioned o centrally register the film with respect to the container 2 l.

Figures 14 and 15 show'a conventional support for a photographic plate I9. The plate I9, shown outlined in dot-and-dash, ts in an upwardly open U groove 48 of the channel frame structure. l

The channel structure is fastened at the top to a cross member 21 dimensioned to rest across the walls of the container 2| and provided with down- Ward lugs 41 for properly registering the support, and, therefore, the plate 2| carried by it, with respect to the container 2|, of developer solution.

It will be evident that while the invention is particularly applicable to the processing of lms and plates to be employed in producing photoengraving or photo-offset plates, especially for color work, the invention is Aby no means limited to this eld, and has application generally in the photographic developing eld for processing still pictures and moving picture film.

To simplify the references to the photographic material under process, it is described in the claims as film, regardless of whether in fact it isstill?- or resilient, and whether, therefore, it would be generally known as a 111m or a plate.

In view of my invention and disclosure variations and modiiications to meet -individual whim or particular need will doubtless become evident to others skilled in the art, tov obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as -they fall within the reasonable spirit and scope oi' my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters 4lI-at-y reciprocating the agitator across the surface of a nlm in a direction parallel to the surface, and means whereby the agitator yields' under the action of liquid ow at the end of each reciprocation.

2. In a photographic bath agitation device, in-

- cluding means for supporting a submerged film out of contact with agitating structure, the combination of an agitator of blade form, a reciprocator moving longitudinally of the surface of a illm being processed, pivotal means whereby the agitator is reversably supported on the reciprocator with the agitator inclined toward the iilm on each reciprocation, and limiting means for the agitator to restrict its angle of inclination.

3. In a device for processing a photographic nlm, while the lm is supported vertical and submerged in a processing solution within a container, an agitator adapted to be reciprocated transversely across the submerged film, a reciprocator for the agitator operatively connected thereto, maintaining the agitator at all times out ofl contact with thek illm, and means whereby at the beginning of each reciprocator stroke the` agitator is yieldable with respect to the reciprocator in a direction counter to that of the beginning stroke and to the greater pressure Aof the liquid in front of the agitator.

4. The structure of claim 3 in which the reciprocation strokes of the agitator at the portion thereof near the film are eiectively as great as the width of the illm.

5. The structure of claim 3 and in which the reciprocation strokes of the agitator are effectively greater than the width of the lm.

6. The `structure of claim 3 and in which the length of the agitator is at least as great as that of the iilm.

7. The structure of claim 3 in which the length of the agitator is as great as that of the lm and the reciprocation strokes at the portion of the agitator near the film are eectively as great as the width of the film.

8. The structure of claim 3 and in which the,

portion ,of the area of the processing solution in a direction transverse tothe direction of the reciprocation strokes.

11. The structure ot claim 3 and in which the agitator is aap having pivot connection with the reciprocator at-the ap side further from the lm, in combination with means limiting the hinge movementof the flap. I

12. 'I'he structure of claim 3 and in which the agitator is a flexible sheet having a free side toward the iilm and the other side attached to the reciprocator.

13. The structure of claim 3 and in which the agitator has a lost motion slide connection with the reciprocator.

14. 'I'he structure of claim 3 and in which the reciprocator comprises a tube to be reciprocated longitudinally, the agitator intermediate its length having pivot support on the t'ube, with the agitator and its pivot both transverse to the tube length, and with the pivotal movement of the' agitator limited by its engagements with the tube.

15. The structure of claim 3 and in which the reciprocator comprises a tube to be reclprocated longitudinally, the agitator intermediate its length having pivot support 'on the tube transverse to the tube near the middle thereof, having pivots at theagitator ends and a supporting connection between the end pivots and the back oi' the tube.

16. In a device for processing photographic lm while it is in vertical position and submerged in a processing solution within a container, operating simultaneously upon two lms, one toward each of opposite sides of the container, an agitator transversely across and between the submerged films, a reciprocator operatively connected to the agitator'at a portion thereof intermediate the agitator portions near the opposite lms, maintaining the agitator at all times out of contact with the tllms, and means whereby at the beginning of each reciprocator stroke the agitator portions toward the lms are yieldable with respect to the reciprocator in a direction counter to that of the beginning stroke and to accommodate the greater pressure of liquid in front of the agitator.

17. The structure of claim 16 and in which the agitator comprises aps hinging to opposite sides of the reciprocator with a limited range of hinging movement.

18. The structure of claim 16 and in which the agitator comprises a flexible sheet intermediately fastened to the reciprocator and with free opposite edges presented toward the opposing films.

19. The structure of claim 16 and in which the agitator comprises a plate having an intermediate limited slide connection with the reciprocator and with its opposite edges toward the opposing lms. i CARL C. CHAMBERS.

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