US2747482A

US2747482A - Film developing and processing tank

Info

Publication number: US2747482A
Authority: US
Inventors: Leonard W Gacki; Walter A Winfield
Original assignee: X RAY INSTR CORP
Current assignee: X RAY INSTR CORP; X-RAY INSTRUMENT Corp
Priority date: 1954-01-18
Filing date: 1954-01-18
Publication date: 1956-05-29
Anticipated expiration: 1973-05-29

Description

29, 56 L. w. GACKI ET AL 2,747,482

FILM DEVELOPING AND PROCESSING TANK Filed Jan. 18, 1954 5 Sheets-Sheet l LEONARD W. GACKI WALTER A. WINFIELD INVENTOR.

BYZWMM ATTORNEY y 1956 L. w. GACKI ET AL FILM DEVELOPING AND PROCESSING TANK 5 Sheets-Sheet 2 Filed Jan. 18, 1954 FIG. 2

LEONARD W. GAC-KI WALTER A. WINFIELD INVENTOR.

ATTORNEY y 29, 1956 L. w. GACKI ETAL 2,747,482

FILM DEVELOPING AND PROCESSING TANK Filed Jan. 18, 1954 3 Sheets-Sheet 3 FIG. 3

LEONARD W. GACKI WALTER A.W|NFIELD INVENTOR.

ATTORNEY FILM DEVELOPING AND PROCESSING TANK Leonard W. Gaclti, Jamaica, and 'Walter A. Winfield,

Bronx, N. Y., assignors to X-ray Instrument Corporation, a corporation of New York Application January 18, 1954, Serial No. 404,739

4 Claims. (Cl. 95%) This invention relates to a film processing and developing tank. Particularly the invention is concerned with a tank suitable for X-ray film processing wherein a cascade engendering barrier limits the capacity of one portion of the tank and permits displacement of fluid in excess of the capacity so limited into another portion of the tank equipped with separate, accessible drainage facilities.

Film processing and developing tanks of the cascade type have not heretofore been successfully applied to processing X-ray film. Available tanks of this type have either lacked facilities for preventing or limiting the corrosive action of residual hypo or other reactants upon the tank walls or fixtures, or they have not been provided with accessible facilities for cleaning. conventionally applied tanks of this description are equipped for supporting film hangers and auxiliary processing tanks in the washing fluid suspended from brackets spot Welded or otherwise attached to the tank interior. These and other projecting parts obstruct the normal circulation of the washing fluid causing the formation of pockets of stagnation which render difficult the maintenance of critically even temperature of the processing solutions. Sluggishness in the circulatory system further abets the accumulation of chemically active impurities which may stain, fog or otherwise irretrievably damage valuable negatives in process. A further and probably more serious limitation may be attributed to incorrect placement or extent of the cascade with respect to the circulatory path of the processing fluid and also with respect to the surface of the fluid within the tank and to the drainage system. irregularities in the distribution of temperature and in the disposal of waste materials thus are accentuated.

Accordingly, the present invention is directed to the provision of a film processing and developing tank having an improved, inlet applied, circulatory system.

Another object of the invention is the provision of a cascade type film developing tank having smoothly contoured, temperature insulated, interior Wall surfaces forming parallel supports for the suspension of interchangeable containers for processing solutions and for film racks within the liquid in the processing compartment of the tank.

A further object of the invention is the provision in a cascade type film processing tank, of improved drainage and cleaning facilities.

A still further object of the invention is an improved cascade forming barrier within a film processing tank separating the interior of the tank into a processing compartment and a drainage compartment; the processing compartment being disposed for the eflicient distribution throughout the tank interior of controlled temperature by turbulently circulated liquid which, subsequently, is cascaded over the barrier into the drainage compartment.

For a better understanding of the invention together with other and further objects thereof, reference is had to the following drawings and description in connection with the appended claims defining its scope.

Fig. 1 is an isometric representation of a compartmented, film processing tank with separately contained processing solutions and film holders suspended in one compartment and with liquid and impurity concentrating drainage facilities shown in another compartment.

Fig. 2 is a side view of the tank of the invention with a portion of one wall broken away to show the cascade forming barrier, the compartmented interior and the associated fluid supply and drainage systems.

Fig. 3 is a rear elevation of the tank of Fig. l, depicting a preferred arrangement of piping and connections appended to a phantom view of the tank.

As shown in Figs. 1 and 2, the film processing and developing tank 1, of the invention has walls 2, 8, 9, 1t), and bottom 3, of stainless steel sheeting, temperature insulated by an interior layer 4, of plywood, glass wool or other suitable material. In some instances it may be found preferable to provide the interior stainless sheathing with a backing of wood instead of metal. Tank inlet 5, preferably located in rear wall 8, at a suitable height above the tank bottom, may have threaded extensions adapted to the application of various types of spraying heads or jet nozzles for altering the direction or characteristic of the circulatory path of the temperature controlled water delivered to the tank from conventional tempering valve 21 generally placed within convenient reach of an operator for adjustment of temperature and pressure of the washing fluid in a manner well understood in the art. Drainage outlet 6, through the tank bottom, is provided for discharging processing compartment 15, when it is desired to empty the tank. Another outlet 7, the purpose of which is described hereafter, is shown extending vertically through wall section 8. Longitudinally of opposite walls 2 and 8, and preferably formed integrally therewith, are parallel projecting supports 11, contoured to present minimum interruption to the path of circulation of the water in the processing compartment. These parallel supports extend the full width of the processing compartment. From them may be suspended film racks l2, and as many auxiliary tanks or containers 13, as may be re quired for the solutions necessary for developing, hardening, fixing and other operations conventionally applied in tanks of this description. To maintain the level of the separate processing solutions in the auxiliary containers above the normal working level of the liquid in the processing compartment, the auxiliaries have projecting members 14, mating with the parallel supports to maintain the open ends of the containers above the established liquid level. Similarly equipped for suspension within the fluid either inthe auxiliaries or in the processing compartment, are film racks 12, having protecting members 16, on their upper structures, so arranged that the film 17, within the racks will be suspended completely below the surface of said fluids during developing operations.

Auxiliary tanks and film racks are interchangeable so that no delay need be experienced in their replacement or transfer from one processing operation to the next.

While the tank of the invention is shown as a coverless structure, it will be understood that, for reducing oxidation or other purposes, a cover could be provided without materially altering the scope of the invention.

The apparatus so far described is well known in the art and, except as necessarily included in combination with other elements, forms no part of the invention claimed. As indicated, a developing solution may be maintained in one auxiliary tank, a hardening and a fixing solution or a wetting agent in another. Surrounding the suspended auxiliary receptacles and maintained at a level sufliciently below the open ends thereof to prevent seepage thereinto, is Water bath 20, the controlled temperature of which must be evenly distributed throughout the processing compartment.

Processing at excessively high temperature or sudden changes in the temperature of film processing solutions during development are known to cause reticulation, fog- :ging and other deleterious effects. Retardation of normal chemical reactions may be most advantageously overcome in the tank of the invention by maintaining uniform temperature of all solutions at a predetermined level established for the work in process. To this end, the temperature of the water bath in the processing compartment is carefully adjusted and controlled at the tempering valve or other suitable control means and is transmitted by continuous circulation of the water in contact with the auxiliary tanks, thence to the solutions within them. Turbulence is continuously applied to the water in the processing compartment by the forceful injection of a continuous stream through inlet 5, at a predetermined rate of flow usually not in excess of nine gallons per minute. Regardless of the rate of flow or the characteristic path imparted to the circulation of the water by the nozzle applied at the inlet, the level of the Water in the processing compartment can never rise above the height established by the top of barrier 30, which is shown extending longitudinally of the complete interior width dimension of the tank between oppositely spaced walls 9 and ill. Water in excess of the capacity established by the barrier is cascaded over the barrier into drainage compartment 31. The rate of drainage of this compartment, as established by as many screened outlets 7, as may be required, is considerably in excess of the tank inlet capacity, thus assuring that the level of the water in the processing compartment cannot rise to a height endangering seepage into the auxiliary tanks. It is important to note that the cascade forming barrier 30, extends the full interior width dimension between walls 9 and 14). This is also the full width extension of processing compartment 15, and drainage compartment 31. The cascade over the barrier thus effectively drains off along the entire surface of the turbulently circulated fluid in the processing compartment, the comprehensive extent of the spillway thus becomes a factor in the prevention of stagnation and in the eflicient disposal of waste and impurities carried by the cascaded fluid.

Heavier waste materials such as silver particles washed from the negatives in process will sink to the bottom of the processing compartment whence eventually they may be drained off through bottom outlet 6. Lighter waste materials, including scum forming drip, carried by the turbulent washing stream, will swirl to the surface of the liquid in the processing compartment to be cascaded into the drainage system. As is best shown in Fig. 2, the smooth contour of the barrier and channelled receptacle 31 with the extended, outer rear wall of the tank, are efiective as a splash reducer, the wall serving to confine the cascaded liquid within the drainage compartment without spillage. The specific location of the gutter with respect to the barrier and its adjacency to the top of tank ll, provide easy access from outside the tank during processing operations for clearing drains and wiping away the residual accumulation of scum and solid impurities which might otherwise clog or impair the functioning of the drainage system.

The shelf like protrusion of barrier and gutter forming wall 8, bounded on each side by the side walls of the tank provides a recessed area within which piping, valves and accessories may be protectively housed. The preferred arrangement of fluid supply and drainage system is shown in Fig. 3. The recessed enclosure of plumbing connections therein displayed, permits installation of the tank flush with the wall of a laboratory or other interior with no projecting parts exposed to damage from outside the tank and with ample protection against drip or overflow of water or corrosive'solutions from within.

Drainage compartment or receptacle 31, is directly above inlet 5. It is thus located in its most effective position with respect to the circulatory path of the processing liquid and also with respect to the drains 7, in which the cascaded overflow is concentrated and gravitationally delivered through suitable piping shown in communication also with main tank drain 6. Thus, completely within the identified structure comprising the tank of the invention, from inlet to final disposal, is maintained an uninterrupted flow of temperature controlled liquid, evenly distributed to all critical processing areas. To insure uniformity of drainage of waste water and impurities over the barrier, levelling feet 40, may be suitably adjusted at each corner of the main tank.

Illuminated viewing boxes 50, for observing the progress of film development in the darkroom, may be installed adjacent to the tank as in Fig. 1. One view box may house a white light of suitable intensity, the other may contain a safelight having a protecting filter or screen for transmitting only light of a wavelength incapable of damaging partially developed negatives. if the view boxes are located directly above the drainage compartment, the drip from the film may be prevented from contaminating the solutions within the separate auxiliary containers.

While the material of the tank has been specified as stainless steel, hard rubber, synthetic resin, or other corrosion resisting material would equally serve the purposes of the invention. Where desired, the tank wall structure, including the overhanging drainage receptacle, may be unitarily molded of suitable material such as a ceramic.

Having described the apparatus, what is believed to constitute the novel improvement inhering therein is specified in the following claims:

1. In a film developing and processing tank comprising a processing compartment; a drainage compartment extending outwardly of a wall of said processing compartment; a barrier extending between opposite walls of said tank and common to said compartments; means for circulating fluid in said processing compartment lengthwise between processing units interchangeably suspended therein and in a direction normal to said barrier causing portions of said fluid to cascade thereover; a drain extending vertically through the bottom of said drainage compartment for disposal of said cascaded fluid outside said tank.

2. In an X-ray film processing tank equipped for con trol by fluid contact of the temperature of solutions in separately suspended auxiliary containers within a processing compartment, the improvement comprising a barrier extending the full width of said processing compartment at a height substantially below the tops of said containers in suspension; a relatively shallow bottomed compartment bounded by said barrier and extensions of the walls of said processing compartment; means circulating temperature controlled fluid in a direction normal of said barrier and means for vertically disposing of fluid cascaded over said barrier exteriorly of the walls of said tank.

3. A film processing and developing tank of the cascade type comprising a film processing compartment; inlet means in said compartment for circulating liquid at a controlled temperature; means extending along the entire surface of said circulated liquid for cascading excess thereof into a receptacle having an outlet therein, said receptacle and said outlet being located within the casing of said tank at a height substantially above said inlet.

4. A processing and developing tank for X-ray fihn comprising temperature insulated walls and a bottom surrounding a processing compartment; an extension of one of said walls forming a barrier and a shallow drainage receptacle having at least one outlet; the height of said barrier and the discharging capacity of said outlet establishing the level of the liquid in said compartment; and a normally closed, second ouilct adaptable to drainage of the liquid remaining in said processing compartment below the liquid level established by said barrier.

References Cited in the file of this patent UNITED STATES PATENTS Hopkins Aug. 12, 1930 Murk June 7, 1932 Moore Aug. 24, 1943 Powers et al Oct. 11, 1949 Traiber July 31, 1951 Sardeson et al Sept. 22, 1953