US3133490A - Apparatus for developing radiographic films - Google Patents

Description

May 19, 1964 A. w. BUCK 3,133,490

APPARATUS FOR DEVELOPING RADIOGRAPHIC FILMS Filed Jan. 19. 1961 INVENIOR I ARTHUR H. BUCK ATTORNEYS United States Patent 3,133,490 APPARATUS FOR DEVELOPING RADIO- GRAPHIC FILMS Arthur W. Buck, 8709 Xograph Ave., St. Louis, Mo. Filed Jan. 19, 1961, Ser. No. 83,741 1 Claim. (Cl. 95-96) This invention relates to an improved method of developing radiographic films, and to an improved apparatus in which such method can be carried out.

Methods of, and equipment for, developing radiographic films are widely used by physicians, hospitals, clinics, and even several phases of industry. Particularly, in connection with the use of such equipment for medical careand/ or diagnosis, it is commonly necessary to have information contained on properly developed radiographic films immediately because human life is dependent on the procedure to be followed in light of the information gained from the films. Even in industry, however, it is desirable, and in many instances necessary, to'have film developed as rapidly as possible.

While various radiographic film-developing techniques are well known in the art, as are various forms of developing apparatus which facilitate radiographic film processing, there is, to my knowledge, presently available no rapid development technique which can be carried out with inexpensive apparatus.

The prior methods which are used for the purpose in question may generally be classified into two groups, namely, the manual methods and the automatic methods. Previously-suggested methods of the manual type, and apparatus provided for use in connection with such methods, usually incorporate either static fluid tanks, or some form of fluid agitator or fluid circulator. However, almost all, if not all, available manual apparatus and methods utilize static tanks exclusively. Insome instances, temperature control is provided and master tanks are utilized. Notwithstanding the provision of these various expedients in different combinations, the manual methods and associated apparatus presently available require substantial developing time, and usually are space-consuming. Thus, while most of the manual methods and devices have the advantage of relatively low purchase, operation, service, and maintenance costs, the average time r'equired to process a radiographic film according to such methods, and in such devices, is long, averaging approximately one-half hour prior to drying, and this length of time is dangerous in some instances, and undesirable in anyinstance.

The automatic radiographic film-developing technique and associated machines generally operate by conveying the film to be developed through successive treating stations .in such a manner that complete development, aside from drying, can be achieved in a minimum of time, averaging approximately ten minutes. Notwithstanding the advantageous speed of operation of the automatic techniques and machines, they possess one particularly important drawback, namely, the purchase, service and maintenance costs are beyond thereach of all users except the larger institutions.

The present invention is directed to providing a method of developing radiographic films, and an apparatus for carrying out such methochwhich method and appa- V ratus are not subject to the inherent disadvantages of prior suggestions as set forth above. Accordingly, the

present invention has as its primary objects, the pro-' vision of an improved method of developing radiographic films which allows for rapid development by a manual technique, and the provision of improved apparatus which can be inexpensively manufactured and used in carrying out the method of the invention.

More specifically, the primary objects of the present invention are (a) to provide a fast developing method which can be carried out manually; and (b) to provide a suitable inexpensively-manufactured and operated improved apparatus in which the method of the invention can be practiced.

Still further and more specific objects of the present invention are:

(1) To provide a method and apparatus conforming with the preceding objects, which method and apparatus serve to control the temperature conditions of the various fluids used in radiographic film development;

(2-) To provide a method and apparatus as prescribed hereinabove, which method and apparatus serve to maintain the film-processing developing fluids in the state of continuous uniformity of mixture, whereby such .fiuids act on the film with peak etficiency;

(3) To provide such a method and apparatus wherein the readily-available and disposable washing development-fluid, normally water, is utilized initially for washing films being processed, and thereafter for maintenance of temperature control of other developing fluids;

(4) To provide such a method and apparatus wherein the washing fluid is introduced into the processing unit in such a manner as to augment the flow of washing fluid passing about the film being processed;

(5) To provide such a method and apparatus Wherein all developing fluids used in the process are simultaneously circulated and agitated;

(6) To provide a method of developing radiographic films which can be carried out in various forms of inexpensively-manufactured apparatus;

(7) To provide an apparatus in which the method of the invention can be carried out, which apparatus comprises a plurality of developing tanks or chambers so constructed that fluid can be overflowed from one of such tanks and circulated about the others for purposes of temperature control, whereby external and/or separate circulating equipment is not required;

(8) To provide an apparatus conforming with the preceding subparagraph and incorporating in each of the chambers or tanks a circulation passage separate from the treating portion of the chamber or tank, and through which the developing fluids pass for distribution and circulation continuously between the top and bottom of the treating portion of the chamber or tank; I

(9) To provide such an apparatus wherein baffle plates are used to define the circulation passage, and motordriven impellers are used within such passages to cause agitation, as well as circulation, of the fluid passing therethrough, whereby the same is maintained as a substantially uniform mixture, thereby eliminating the development of concentration gradients adjacent the surface of films being treated; and I p (10) To provide a methodand apparatus conforming with all of the preceding objects, which method, and which apparatus, can be carried out and operated respectively 3 of radiographic films prior to drying. The methods and apparatus discussed herein serve to develop the film to a point where it is ready to be subjected to a suitable drying operation. Thus, the terms developed film and processed film as used hereinafter refer to a film which has been chemically treated and developed to a point where no further operation must be performed thereon other than drying.

While various forms of dryers can be used in association with the methods and apparatus of the present invention, preferably small rapid drying devices are provided for treating films which have been processed in accord ance with this invention. In this connection, it should be pointed out that one of the important objects of the present invention is to provide an apparatus conforming with all of the preceding objects, which apparatus requires a minimum of space.

The invention will be better understood and objects other than those specifically set forth above will become apparent, when consideration is given to the following detailed description of the illustrative and preferred embodiments of the invention. The description refers to the annexed drawings, wherein:

FIGURE 1 is a plan view of an apparatus constructed in accordance with the present invention, which apparatus is suitable for carrying out the method of the present invention;

FIGURE 2 is a cross-sectional view taken on the line 2-2 of FIGURE 1, and presenting in addition to the details of construction of the preferred apparatus embodiment, the manner in which developing fluids are circulated through the apparatus in accordance with the method of the invention; and

FIGURE 3 is a cross-sectional view taken on the line 3-3 of FIGURE 1, and presenting in addition to the details of construction of the preferred form of processing tank used in the apparatus of the invention, the manner in which fluids are circulated within each of the processing tanks or chambers in accordance with the method of the invention.

According to the method of the invention, developing fluid is placed in a first chamber such as that defined by the tank 2 in FIGURE 2. Fixing fluid is placed in a second chamber such as that defined by the tank 4 and washing fluid is introduced into a third chamber, such as that defined by the numeral 6. The washing fluid which is introduced into the washing chamber, is, after traversing the washing chamber, passed into surrounding relation with all of the chambers or tanks 2, 4 and 6. This is achieved, in the apparatus shown in FIGURE 2, by overflowing the Washing fluid from the tank 6 into an outer or master chamber which is defined by the tank 8 as shown. 7

TheWashing fluid Which is passed into the master tank 8, and into surrounding relation with all of the other chambers or tanks, circulates around all of such chambers and then is continuously withdrawn from surrounding relation with all of the chambers through a suitable overflow drain, which, as shown, comprises the overflow conduit 28. The continuous circulation of the washing fluid in surrounding relation to all of the chambers, caused by the continuous introduction and withdrawal of such fluid in and from the apparatus serves to cause the temperature within the various chambers to be'maintained at a predetermined value, whereby no change in temperature is encountered by films being successively placed in each of the processing chambers 2, 4 and 6.

In addition to providing for circulation of the washing fluid in surrounding relation to the various chambers 1 and control of temperature thereby, as described hereinabove, the method of the invention also providesfor continuously circulating the fluids within each of the chambers, and continuously agitating the same to main:

' tain the solutions within each of the chambers uniform throughout, whereby concentration gradients are prethe tanks 2, 4 and 6.

vented from developing adjacent the surfaces of the film. Moreover, the method of the invention provides for introducing the Washing fluid into the washing chamber in such a manner that newly-introduced washing fluid serves to augment the circulation of washing fluid already in such chamber about the surface of the film. Still further, the method of the invention provides for initially passing the washing fluid which is introduced into the system through a suitable heating unit such as that designated by the numeral 26, whereby the temperature of such fluid can be controlled prior to introduction within the system, and whereby the temperature of the fluids within the chambers of the system can be predetermined to provide for maximum efficiency of operation.

It has been found that when the method steps of the invention are carried out as prescribed above, radiographic films can readily be developed, fixed, and washed, whereby they are ready for drying within six minutes time. This, as indicated above, represents a substantial improvement over presently available manual methods which require approximately 30 minutes. Moreover, with the method provided hereinabove, a minimum amount of water is required in operation, and thus operating costs are reduced.

The apparatus provided by the invention for carrying out the method, to which apparatus reference has been made generally hereinabove, generally comprises a rectangular master tank 8 and a plurality of captive tanks 2, 4 and 6, which are disposed Within the master tank in spaced relation to the walls thereof, and in spaced relation to one another. The master tank, as shown in FIG- URE 2, has side walls which extend above the side walls of the captive tanks 2, 4 and 6, whereby the captive tanks have a top plane, designated by the letter P, which is below the top edge 10 of the master tank 8. One of the captive tanks, namely, that into which washing fluid is to be introduced, is provided with a washing fluid inlet conduit.

In the embodiment of the apparatus presented in FIG- URE 2, the washing fluid tank is that designated by the numeral 6, and it is an end tank as opposed to an intermediate tank such as that designated by numeral 4. The

' washing fluid inlet conduit is generally designated by the numeral 24, and communicates with the interior bottom portion of the captive tank 6. The coupling between the conduit 24 and the tank 6 may be of any well known type which is water-tight. Preferably, as explained hereinabove, fluid entering the system through the conduit 24 is initially passed through a suitable heater 26, of any conventional type, whereby the temperature of fluid entering the system can be controlled.

I Each of the captive tanks 2, 4 and 6 is preferably provided with a drain outlet 16 in the bottom wall 18 thereof, and with a suitable stopper 20 for normally closing the outlet 16. The construction of the drain in each of the tanks 2, 4 and 6 is exactly the same, and accordingly, the prime numerals have been used to designate the corresponding walL'plug and outlet.

Each of the tanks 2, 4 and 6 is supported in spaced relation With respect to the bottom Wall 22 of the master tank 8. Means providing such support preferably comprise legs, such as those designated by the numeral 23, or blocks, disposed at each corner of each of the captive tanks 2, 4 and 6 to maintain such tanks above the top surface'of the master tank bottom wall 22, so as to allow fluid to pass under the tanks 2, 4 and 6, or more particularly under the bottom walls 18 thereof.

f The master tank in addition to containing the captive tanks 2, 4 and 6, and in addition to being provided with a suitable sealed inlet 25 through which the fluid inlet 24 passes, is also providedwith an outlet conduit means, which, as shown, takes the form of a vertical conduit 28 extending upwardly within the master tank 8 and terminating just below the plane P defined by the top edges of With this construction, washing fluid is introduced through the heater 26, via the conduit 24, into the captive tank 6 at the bottom thereof. Fluid so introduced passes upwardly through the tank 6 past both sides of any film disposed therein (not shown) and overflows from the top thereof, passing downwardly in the direction shown by the arrows and around the other tanks 2 and 4, as well as the tank 6, ultimately reaching the overflow conduit 28. The fluid which reaches the overflow conduit 28 passes downwardly therethrough and out of the system. The outlet conduit 28 is, of course, passed through a suitable sealing coupling 30, provided in the base of the master tank 8.

When it is desired to drain fluid from the system, then the stoppers 25 can be removed from the outlet orifice 26 provided in the bottom wall 22 of the master tank, and all fluid in the master tank can be drained therefrom. Simultaneously, or later, the stoppers 20 can be removed from each of the developing tanks 2, 4 and 6 and the fluid drained therefrom into the master tank 8, and from the master tank 8 through the outlet orifice 26.

While general'reference has been made to the tanks 2, 4 and 6 hereinabove, and to the outlet openings 16 in the bottoms thereof which serve to provide means for draining the tanks, no reference has been made to the means provided therein for continuously circulating fluid, and/ or to the means provided therein for agitating such fluid. If reference is made to FIGURES 2 and 3, it will be noted that the tank shown in FIG. 3, which is essentially representative of each of the tanks 2, 4 and 6, is provided with a baffle plate 38 extending in spaced parallel relation to one side wall, namely, wall 40 of the tank. The lower end of the baffle plate 38 is provided with an inwardlyflared bottom flange 42 preferably formed by bending Y the plate inwardly and downwardly, and a deflection plate 43 is attached to the wall 40, as by welding or other suit able means, so as to extend in spaced parallel relation to the bottom bent end 42 of the baffle plate 38. The deflection plate 43 and lower end of the bafiie plate 38 serve as a fluid outlet orifice whereby fluid which is passing through the passageway 41 extending between the baffle plate 38 and wall 40 enters the bottom of the tank. The bafile plate 38 is provided, adjacent its upper end, with a suitable opening such as that designated by the numeral 44 through which fluid can enter the passageway 41. As shown in FIGURE 2, a plurality of such openings are preferably provided.

Extending within the passageway 41 is an impeller 50, which impeller preferably comprises an impeller blade 52 carried at one end of a shaft 54 extending from a suitable drive motor of any well known type. The drive motor is designated by the numeral 56 and is supported in position by means of a bifurcated support bracket 58 having an upwardly-extending arm 60 to which the motor is suitably attached, and downwardly-extending spaced-apart support legs 62 and 64 adapted to be passed over and secured to the wall 76 of the master tank. The impeller blade 52 is formed in any well known manner so as to direct fluids in the passageway 41 between the bafile plate 38 and wall 40 downwardly within the tank. As the fluid is directed downwardly within the tank, it enters the bottom thereof, thereby causing fluid within the tank to move upwardly, and as the fluid moves upwardly, it enters the opening 44 in the baffle plate 38 and moves again into the passageway 41. Thus, the impeller serves as a means to cause continuous circulation of fluid within the tank and, in addition, the impeller serves to agitate the fluid. This continuous circulation and agitation, as explained hereinabove, maintains the fluid within the tanks as a uniform mixture and prevents concentration gradients from developing adjacent the surface of the films being processed.

The tank presented in FIGURE 3 actually comprises the tank 6 presented in FIGURES 1 and 2. However, the tanks 2 and 4 are substantially identical with the The tank 6, however, as sugfluid passing through the conduit 24 can enter the lower portion of the tank. This inlet is designated by the numeral in FIGURE 3 and is disposed beneath and under the deflector plate 43 whereby, newly-introduced washing fluid entering the system through the conduit 24 is directed downwardly under the deflector plate 43 prior to being allowed to rise within the tank 6. As a result of this construction, the method step of using the newlyintroduced washing fluid to augment the circulation within the tank 6 is efficiently and automatically carried out. Althought tanks 2, 4 and 6 have been described as identical, it should be understood that tank 4, which in the apparatus shown, would normally contain the fixer solution, may not, in some instances, as where acidic fixer is used, be provided with the motor-driven agitating equipment.

While not specifically defined as such hereinabove, it will be appreciated that each of the tanks 2, 4 and 6 actually comprises a treating zone and a re-circulation zone. The treating zone is disposed to the left of the recirculation zone. As shown in the tank of FIGURE 3, the recirculation zone is defined by passageway 41 between the batfle plate 38 and the wall 40; and the treating zone is defined to the rightof the baflle plate 38 as shown.

Radiographic films to be processed are, of course, placed successively in the treating zone of each of the tanks whereby the same are first subjected to the conventional developing fluid, then to the conventional fixing fluid and then to a suitable washing fluid such as water. It will also be appreciated that continuous circulation of fluid within the washing tank 6 is obtained simultaneously with overflow of fluid therefrom which passes in surrounding relation to each of the tanks 2 and 4, as well as the tank 6 from which it has overflowed.

After reading the foregoing detailed description of the preferred and illustrative embodiments of the method of the invention, as well as the apparatus embodiments thereof, it will be appreciated that the objects set forth at the outset of this specification have been successfully achieved. It will also be apparent that various modifications can be made to the exact structure shown without departing from the scope and spirit of the invention.

Accordingly, what is claimed is:

In an apparatus for developing radiographic films, the combination comprising: a master tank having a bottom wall and a plurality of side walls; a plurality of captive tanks adapted to contain developing, fixing, and washing fluids respectively, each of said captive tanks having a plurality of supporting legs disposed at each corner thereof for supporting said captive tanks above the bottom wall of said master tank and in spaced relation to the side walls thereof, each of said captive tanks having side walls terminating below the side walls of said master tank, a washing fluid inlet conduit communicating with the interior bottom portion of one of said captive tanks below the vertical center thereof; heater means disposed exteriorly of said master tank, said washing fluid inlet conduit being connected at one end thereof to said heater means; awashing fluid outlet conduit communicating with said master tank, said washing fluid outlet conduit being vertically disposed at one end of said master tank and terminating at a point vertically below the imaginary horizontal plane defined by the tops of each of said captive tanks, whereby washing fluid can be continuously passed through said heater means into said inlet conduit and into said one captive tank and continuously overflowed from said one captive tank into said master tank in surrounding relation with all of said plurality of captive tanks, thereby continuously circulating around said captive tanks and being withdrawn through said washing fluid outlet conduit from said master tank thereby continuously controlling the temperature of fluids in said captive tanks; each of said captive tanks being provided with a drain outlet in the bottoms thereof communicating with said master tank and a stopper for closing said outlets, said master tank having an outlet orifice and a stopper therefor horizontally spaced from said outlet conduit and being disposed between two of said captive tanks 5 for draining all fluids within said master tank therefrom; agitating means disposed in at least two of said captive tanks and cooperating with a vertical bafile plate extending in parallel spaced relation to one of said side Walls of each of said two captive tanks, said baffle plates having 10 openings in the lower portions thereof.

References Cited in the file of this patent UNITED STATES PATENTS Hopkins Aug. 12, 1930 Dignan Oct. 22, 1957 Hiserman Nov. 17, 1959 Bridgman et a1 Nov. 24-, 1959 Dyck June 6, 1961 FOREIGN PATENTS Austria Mar. 25, 1960

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