US3682080A

US3682080A - Apparatus for developing photographic films

Info

Publication number: US3682080A
Application number: US87493A
Authority: US
Inventors: Werner Merz
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-11-13
Filing date: 1970-11-06
Publication date: 1972-08-08
Anticipated expiration: 1989-08-08
Also published as: DE1957069B2; DE1957069A1

Abstract

One or more developing drums having spaced opposite ends are mounted for rotation in a housing and a supply supplies liquid developer to the interior of these drums. Raising arrangement utilizing eccentric cams or the like is provided for alternately raising or lowering one end of each drum at predetermined time intervals and through a predetermined distance to thereby cause longitudinally traveling waves of the developer in the drums.

Description

[15] 3,682,080 [4 1 Aug. 8, 1972 United States Patent Men [541 APPARATUS FOR DEVELOPING 12/1966 Hallquist........t..............95/99 95/93 3,292,519 2,947,236 8/1960 Siege].....................

Primary Examiner-Samuel S. Matthews Assistant Examiner-Richard M. Sheer Attomey-Mibhael S. Striker 791 l Oberelchingen, Germany Nov. 6, 1970 [22] Filed:

ABSTRACT.

[2!] Appl. No.: 87,493

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BACKGROUND OF THE INVENTION The present invention relates generally to photographic apparatus, and more particularly to apparatus for developing photographic films. 1

The term photographic film as employed herein is intended to refer generally to all photographic film materials in their broadest form. Obviously this includes sheet material-type films, strip-shaped films and the like. The present invention is particularly ad vantageous, however, with respect to sheet-material shaped films. I

It is already known from the art to provide an apparatus for developing photographic films of the sheetmaterial type in which developer drums are rotated and accommodate both the film to be developed and a liquid developer which is needed to develop the film and which is to be brought into uniform contact therewith. A different approach known from the art provides for a housing which is sealed against the entry of light and in which there is mounted an elongated tray pivotable about its longitudinal axis. A rotatable drum, on which the photographic material to be developed is mounted, rotates and dips the photographic material into the developer accommodated into the tray. According to a preferred embodiment of this latter prior art construction the drum should be configurated as a paddle wheel with the film material to be developed being supported on this paddle wheel.

These constructions known from the prior art are by no means inoperative. However, it has been found that p it is impossible to provide-by utilizing them adequate developing of modern photographic materials, the reason being that such modern photographic materials are highly sensitive to flaws in the developing process. In particular it has been found that with these known prior art constructions it is very diificult to so wash the photographic materials with the developer liquid that the materials are uniformly treated with the liquid in a manner avoidingthe formation of schlieren and of developing irregularities. The term schlieren designates a phenomenon in which streaks develop and is known to those skilled in the art.

SUMMARY OF THE INVENTION tively simple in its construction but highly reliable and efficient in its operation.

A concomitant object of the present invention is to provide such an apparatus which is simple to operate.

In pursuance of the above objects, and others which I Supply means is provided for supplying liquid developer to the interior of the drum and raising means is provided for raising of the ends of the drum at predetermined time intervals and through a predetermined distance.

In this manner I assure that at these predetermined time intervals the developed liquid will travel through the drum in the form of a longitudinally advancing (with respect to the elongation of the drum) wave which will uniformly wash over the film material contents of the drum. When the wave reaches the opposite end it is reflected therefrom and travels back towards the first or one end where it originated and which in the meantime has been allowed to descend to its starting position. Now the one end is raised again and the travel of the developer liquid is renewed. Of course, the intervals at which the one end of the drum is raised, and the distance through which it is raised, are synchronized with the travel of the wave so as not to interfere with the same.

When the film materials, particularly sheet-like film materials, are accommodated in the interior of such a developer drum which rotates and is raised in the manner just discussed, they no longer simply in effect slide into the more or less stationary developing liquid, but instead are subjected to the washing action of the developer liquid waves which travel to and fro between the opposite ends of the drum. This assures a constant uniform contacting of the film material with the developing liquid.

Various different ways are conceivable and suitable for raising the drum. According to a particularly simple concept of the invention I provide for an excenter drive utilizing an excentrically mounted rotating cam which is located between one end of the drum and so arranged that as the cam rotates, it contacts the exterior of the drum and lifts this one end thereof upwardly by the desired predetermined distance. This is a mechanically rather simple construction which is yet highly reliable and in which the distance through which the drum is raised, and the time intervals at which it is raised, can

will become apparent hereafter, one feature of the in- Y vention recites in an apparatus for developing-photographic film which, briefly stated, comprises a housing, at least one developing drum in the housing and having spaced opposite ends, and drive means mounting the drum for rotation about a substantially horizontal axis.

' mental to the desired formation of the wave be varied by exchanging the cam for another one. The opposite end of the drum may be pivotably mounted on the support of the apparatus, for instance a supporting table or the like.

It is also advantageous according to a further conceptv of the invention to construct the drum of two parts, a main part and a terminal part which is located at that'end of the drum where the developer liquid is to be poured out when it is spent. The terminal part tapers conically in direction away from the main part and intermediate the two an annular member may be accommodated in the interior of the drum and be provided into its outer edge with inwardly extending recesses. The conical part facilitates pouring-out of developer liquid when the latter is to be replaced with new liquid. On the other hand, its internal taper would be detrito and fro in the area of the drum, because the taper of the inner wall surface of the conical portion would not properly reflect the wave back in the opposite axial direction. This difficulty is overcome by providing the annular element which provides for such reflection but which, due to the recesses in its outer periphery, does not hinder pouring-out of the developer liquid when such is desired.

travelling It is advantageous but not necessary that the inner diameter of the central aperture in the annular element be so selected that as the wave of developer liquid is reflected from the annular element, the liquid will not pour through the central aperture. Of course, to do this it is necessary to take into consideration not only the diameter of the central aperture but also other factors such as the distance through which the one end of the drum is raised, the periodicity at which it is raised and the quantity of developer liquid which is to be accommodated in the drum. However, a simple experimentation will readily enable anyone skilled in the art to determine these factors and their co-relationship. In a similar manner the optimum number, location and configuration of the recesses in the outer periphery of the annular member can be empirically determined.

It is also advantageous to have the one end of the drum initially open with a removable ring of resilient material, for instance an elastomeric material, placed over it in fluid-tight relationship with the circumferential wall of the drum. The ring again has a central aperture which is selected in such a manner that the wave of developer liquid is reflected from it the ring but that no developer liquid will pour through the central aperture.

The drum or drums may be supported on rotating drive rollers, and according to the invention it is advantageous if these drive rollers are driven by a prime mover, usually an electromotor, which permits them to be intermittently driven rather than continuously. This is a further measure which quite substantially improves the contact between the film material and the developer liquid.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION THE DRAWING FIG. 1 is a partially sectioned end view of an apparatus according to the present invention;

FIG. 2 is a cross-section through one of the developer drums of the apparatus shown in FIG. 1, looking from the left towards the right in FIG. 3;

FIG. 3 is a partial longitudinal section through the apparatus of FIG. 1; and

FIG. 4 is a longitudinal section through the developer drum in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail it is firstly pointed out that the single exemplary embodiment shown in FIG. 1 is just that, namely an example, and that various modifications can and are intended to be incorporated within the context of the present invention.

FIGS. 1 and 3 show that the apparatus according to bodirnent, with a mounting arrangement including support or table 2 which rests on legs or uprights 1. At one axial end of the table 2 there are provided two transversely spaced bearing brackets 8 each of which carries a shaft 7. Mounted turnably on each of the shafts 7 is a lug 6 which in turn is secured to the housing 3 of the apparatus.

The lugs 6 are secured to the housing 3 adjacent one end of the elongated housing, and in the region of the opposite end of the housing 3 there is provided raising means for alternately raising and lowering one end of the housing and thereby of the developer drum 4 accommodated therein. This raising means is here in form of an excentric cam disc 11 mounted on a shaft 9 which in turn is joumalled in the bearing brackets 10 (compare FIGS. 1 and 3) and driven in rotation by the geared motor 12 which can be of any of the various well-known prior art constructions. Evidently, as the shaft 9 is driven in rotation and consequently the excentric cam disc 11 is similarly rotated, it being understood that the cam disc 11 is fast with the shaft 9,

the housing 3 is periodically raised and lowered by a distance which, together with the periodicity, depends upon the eccentricity of the cam disc 1 1. When the disc is circular as illustrated, the raising and lowering movement is sinusoidal as related to time, but it will be appreciated that any other configuration can be obtained by diflerently configurating the cam disc 1 l.

I have illustrated an apparatus in which the housing 3 accommodates two elongated developer drums 4, but it will be understood that the invention is similarly applicable even if there is a single one of these drums 4 providedor if there are more than two of them. The drums 4 are each mounted for rotation on the drive rollers 5 which in turn are connected with a drive shaft 24 joumaled in the illustrated bearing brackets 25 and being rotated intermittently by the geared drive motor '23. Motors for this purpose are known and need not be further described because in themselves their construction does not form a part of the present invention.

It is pointed out, however, that a separating wall in the housing 3 separates that portion thereof which accommodates the drums 4, from a separate chamber 26 in which the motor 23 is located. At the same time, the chamber 26 also accommodates a container 21 constituting a part of supply means which supplies liquid developer to the interior of the drums 4. This is accommplished by having the liquid developer (shown in the receptacle 21 in FIG. 3) pass through an illustrated conduit in which an illustrated valve in interposed (neither identified with separate reference numerals) into the interior of the respective drums 4.

The drums 4 are open at the ends facing the chamber 26 in the illustrated embodiment, and are provided with end caps which are of annular configuration and identified with reference numeral 18. They consist of a resilient material, for instance an elastomeric material as illustrated, and are provided with a central aperture 27 whose diameter is so selected that the waves of developer liquid travelling longitudinally of the drums 4 will not pour through the central aperture 27.

In the region of the opposite axial end each of the drums 4 in the illustrated embodiment is provided with a conically converging or tapering terminal portion 16 the present invention is provided, in the illustrated emthrough whose opening the developer liquid is to be poured out when it is used up or spent. This is done when the apparatus is not in operation, that is when the drums 4 do not rotate, at which time the left-hand end of the respective drum 4 can be raised (for instance by disconnecting it from the end cap 18) so that the developer liquid will pour out through the opening of the terminal portion 16. At this time the drum 4 is supported by the bearing bracket 20 illustrated in FIG. 3.

As FIGS. 2-4 show most clearly, I also provide at the juncture between the main portion of the respective drum 4 (that is the cylindrical portion) and the convergent terminal portion 16, an annular member 17 having a central aperture 28 corresponding approximately to the central aperture 27 and preventing due to the diameter selected for it, pouring-out of the travelling wave of developer liquid. The purpose of element 17 is, of course, to reflect the wave as it reaches the element 17, because the convergent inner surface of the sectional portion 16 would not provide for a proper reflection. As shown particularly in FIG. 2, the element 17 is provided in its outer periphery with inwardly extending recesses, cutouts or the like which are identified with reference numeral 19 and which, while they do not prevent reflection of the traveling wave of developer liquid, make it possible to readily pour out the developer liquid when the drum is raised in the manner discussed before, that is by raising it at the left-hand end rather than at the right-hand end (as in FIG. 3) where the raising is accomplished with the eccentric cam disc 11 and not for the purpose of pouring the liquid out but only in order to produce a traveling wave of liquid.

The drums are each provided in their interior with supports 15 on which the film material to be developed is supported so it can slide circurnferentially of the drums as they rotate.

It will be appreciated that by resorting to my invention a much-improved contacting of the film material with the developer liquid is obtained, and that this contacting is not to any appreciable extent diminished in such embodiments where I provide the element 17 with the cutouts or apertures 19 therein.

It will be understood that each of the elements described above, or two or more together, may also I find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus for developing photographic film, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations-should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. In an apparatus for developing photographic films, in combination at least one developing drum having spaced opposed ends and being adapted to contain therein photographic films and developing fluid; ti siinii i oil fi ix isf diii fiffihifii said drum; and raising means cooperating with said drive means for affecting sequential raising and lowering one of said ends of said drum during rotation of the latter for creating therein longitudinally travelingwaves of developing fluid in a substantially axial direction of said drum to improve development of photographic films contained therein.

2. In an apparatus as defined in claim 1, wherein said raising means comprises excenter drive means beneath and operative for raising said one end.

3. In an apparatus as defined in claim 1, said raising means comprising eccentric cam means.

4. In an apparatus as defined in claim 1, said drive means comprising drive rollers supporting said drum and operative for rotating the same about said axis.

5. In an apparatus as defined in claim 1; and further comprising mounting means mounting said drum in the region of the other of said ends for pivotal displacement about an other substantially horizontal axis extending transversely to the first-mentioned axis.

6. In an apparatus as defined in claim 5; further comprising a support; and wherein said mounting means mounts said drum on said support. a

7. In an apparatus as defined in claim 1, said drum having a main portion, and a terminal portion tapering conically away from said main portion and towards said one end, said terminal portion having an outlet opening for developing fluid in the region of said one end; and further comprising an annular member accommodated in said drum at the juncture of said portions and being provided with circurnferentially spaced recesses for facilitating movement of developing fluid between said portions.

8. In an apparatus as defined in claim 7, said drum accommodating a predetermined quantity of developing fluid and said annular member having a central aperture whose diameter is so selected with reference to said quantity and said distance that waves of developing fluid resulting from said raising and travelling longitudinally of said drum, are prevented from passing through said central aperture.

9. In an apparatus as defined in claim 1, said drum being open at said one end; and further comprising a cap of resilient material overlying and substantially closing said other end in removable relationship therewith.

10. In apparatus as defined in claim 1, said drive means comprising drive rollers supporting and rotating said drum, and motor means for intermittently rotating said drive rollers.

Claims

1. In an apparatus for developing photographic films, in combination at least one developing drum having spaced opposed ends and being adapted to contain therein photographic films and developing fluid; mounting means mounting said drum for rotation about a substantially horizontal axis; drive means for rotating said drum; and raising means cooperating with said drive means for affecting sequential raising and lowering one of said ends of said drum during rotation of the latter for creating therein longitudinally traveling waves of developing fluid in a substantially axial direction of said drum to improve development of photographic films contained therein.

6. In an apparatus as defined in claim 5; further comprising a support; and wherein said mounting means mounts said drum on said support.

7. In an apparatus as defined in claim 1, said drum having a main portion, and a terminal portion tapering conically away from said main portion and towards said one end, said terminal portion having an outlet opening for developing fluid in the region of said one end; and further comprising an annular member accommodated in said drum at the juncture of said portions and being provided with circumferentially spaced recesses for facilitating movement of developing fluid between said portions.