US3727535A

US3727535A - Photographic processing apparatus

Info

Publication number: US3727535A
Application number: US00075605A
Authority: US
Inventors: R Streeter
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-09-25
Filing date: 1970-09-25
Publication date: 1973-04-17
Anticipated expiration: 1990-04-17
Also published as: CA928558A

Abstract

Apparatus for processing photographic materials such as film or paper prints. The apparatus comprises: an elongated horizontal housing having a top wall provided with an access opening sealed by a lid, a horizontal cylindrical drum mounted in the housing for rotation on its longitudinal axis, a solution tray pivotally mounted in the housing below and drum for movement between an operative position and a dumping position for discharging spent solution, and a distribution pipe for supplying treatment solution to the tray. The drum is provided with an opening in its periphery having two parallel rims extending along the longitudinal axis of the drum and a scooping lip mounted on one of the said rims. The sheets of photographic material are placed in the drum through the opening and the sheets are secured inside the drum by adjustable bars detachably fixed on the inside periphery of the drum. The drum is then continuously rotated about its horizontal axis and a predetermined amount of treatment solution fed into the tray. As the drum rotates the scooping lip scoops up the solution into the drum so that the photographic sheets are continuously brought into contact with the solution. The tray is then tilted to discharge the solution and a succession of treatment solutions are fed into the tray in the foregoing manner until the photographic sheets are processed.

Description

United States Patent 11 1 Streeter PHOTOGRAPHIC PROCESSING APPARATUS [76] Inventor: Ro b FfG. H. Streeter, 124 8th Street, Toronto 14, Ontario, Canada [22] Filed: Sept. 25, 1970 [21] Appl. No.: 75,605

52 US. Cl ..95/93 51 11 1. C1. ..G03d 3/06 58 FieldofSearch ..95/89 R, 93,96,

' [56] References Cited UNITED STATES PATENTS Primary Examiner-Samuel S. Matthews Assistant ExaminerFred L. Braun AttorneyGeorge H. Riches 1451 Apr. 17, 1973 ABSTRACT Apparatus for processing photographic materials such as film or paper prints. The apparatus comprises: an elongated horizontal housing having a top wall provided with an access opening sealed by a lid, a horizontal cylindrical drum mounted in the housing for rotation on its longitudinal axis, a solution tray pivotally mounted in the housing below and drum for movement between an operative position and a dumping position for discharging spent solution, and a distribution pipe for supplying treatment solution to the tray. The drum is provided with an opening in its periphery having two parallel rims extending along the longitudinal axis of the drum and a scooping lip mounted on one of the said rims. The sheets of photographic material are placed in the drum through the opening and the sheets are secured inside the drum by adjustable bars detachably fixed on the inside periphery of the drum. The drum is then continuously rotated about its horizontal axis and a predetermined amount of treatment solution fed into the tray. As the drum rotates the scooping lip scoops up the solution into the drum so that the photographic sheets are continuously brought into contact with the solution. The tray is then tilted to discharge the solution and a succession of treatment solutions are fed into the tray in the foregoing manner until the photographic sheets are processed.

13 Claims, 5 Drawing Figures AHornQY Patented April 17, 1973 2 Sheets-Sheet 1 BY @am Patented April 17, 1973 3,721,535

2 Sheets-Sheet 2 lnvenror Roberf G H STreerer Arrorney PIIOTOGRAPHIC PROCESSING APPARATUS BACKGROUND OF THE INVENTION 1. Field oflnvention The present invention relates to photography and, more particularly to an improved method and apparatus for processing photographic materials such as photographic film and paper prints.

2. Description of the Prior Art The processing of photographic material requires the treating of the surface of the material successively with different solutions, e.g., developer, stop-bath and fixing solutions are utilized respectively, in the treating of film. If the photographic material is a paper print, it is only required that one surface of the print be treated with the solution, namely, the exposed surface containing the light-sensitive coating or emulsion. However, in the processing of photographic film it is necessary that both the emulsion side and the opposite side of the film be treated. The size of the prints to be processed may vary, for example, from as large as 30 X 40 inches to as small as 2 X 3 inches.

In the prior art although various photographic apparatuses have been devised for processing film and paper prints, the operation of such devices are presented difficulties and problems in one or more of the following areas;

a. Wasteage of photographic solutions occurs particularly when manual methods are employed utilizing open trays.

b. In automatic processing utilizing rotating drums difficulties have been experienced in maintaining effective solution contact with the the emulsion surface and in maintaining uniform treatment and flow characteristics between successive steps in the process.

c. The number and/or size of prints handled at one time is limited. The devices may only handle a single print during each process or are limited to a small number of prints of specific size.

d. The overall process time for completing the development is lengthy as a result of inefficient methods of changing solutions during the various steps in the process.

SUMMARY OF THE INVENTION required is considerably less than that required in apparatus heretofore utilized in processing photographic material.

It is yet a further object of the present invention to provide photographic apparatus which is readily adaptable to handle either paper prints or film in a range of different sizes and which will process a number of prints at the same time. Further, the apparatus includes means whereby the prints or film may be easily and speedily secured to and removed from the apparatus. I

A further object of the invention is to provide photographic apparatus in which the photographic materials are treated continuously with a succession of treatment solutions in order to reduce the overall process time.

It is yet a further object of the present invention to provide apparatus of the type specified which achieves efficient results in processing photographic material but which can be economically manufactured and easily assembled and which is sturdy and reliable.

To accomplish 'these and other objects there is provided apparatus for processing exposed sheets of photographic material comprising an elongated horizontal housing which includes end walls, side walls, a bottom wall and a top wall provided with a first elongated opening which is sealed by means of a hinged lid. A horizontal drum is enclosed in the housing and the drum is rotated about its longitudinal axis by means ofa conventional power unit. The drum comprises a cylinder having spaced apart circular end plates and is provided with a second elongated opening positioned in the periphery of the cylinder for access to the interior of the drum. The said opening in the drum is defined by two parallel rims extending along the longitudinal axis of the drum between the said end plates and one of the rims is provided with a scooping lip. One or more adjustable bars are detachably fixed to the inside periphery of the drum and serve as means for securing the photographic material.

An open solution tray, hemi-cylindrically shaped, is pivotally mounted in the housing below the drum and is movable between a first operative position in which treatment solution is brought into contact with the scooping lip on the drum and a second position in which the treatment solution is discharged from the tray.

Processing solutions are introduced into the tray by means of a perforated distribution pipe which extends horizontally along the length of the tray and the spent solutions are discharged from the tray into the bottom of the housing which is provided with a discharge conduit.

In carrying out the method of the present invention the sheets of photographic material are placed in the drum through the second elongated opening. The sheets are bent to conform to the inside curvature of the drum and then secured to the said bars fixed on the inside periphery thereof. The drum is then continuously rotated about its horizontal longitudinal axis and a predetermined amount of treatment solution is supplied to the solution tray. As the drum rotates the scooping lip mounted thereon sweeps past the inside bottom wall of the solution tray and scoops up the solution into the drum so that the photographic material is continuously passed through the solution. After a predetermined time the solution tray is then tilted and the solution in the tray and drum discharged into the bottom of the housing. Successive treatment solutions are introduced into the drum in the foregoing manner until the photographic material is processed.

These and other objects, features and advantages of the invention will be apparent from the following specification taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS and the lid on the housing in the open position;

FIG. 4 is an enlarged sectional view similar to FIG. 3 showing the solution tray in the operating position with the scooping lip sweeping the tray;

FIG. 5 is an enlarged sectional view similar to FIG. 4 but showing a modified form of scooping lip.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail, wherein like reference characters indicate like parts throughout the several figures, the reference number indicates generally photographic apparatus constructed in accordance with the invention. In the preferred embodiment the apparatus is provided with an elongated rectangular housing comprising end walls 11 and 12,

side walls

13 and 14, top wall 15 and bottom wall 16.

As better illustrated in FIG. 1, an interior wall 17 divides the housing into two

compartments

18 and 19, the former serving as the main processing chamber and the latter housing a conventional power unit 20.

An elongated rectangular opening 21 positioned in the top wall 15 provides access to the processing chamber 18 and the opening 21 is adapted to be sealed against incidental light by a lid 22 which is attached to the top wall by means ofa hinge 23.

As better illustrated in FIGS. 3 to 5 the lower portion of the

side walls

13 and 14 together with the bottom wall 16 serves as a basin for spent solutions which are discharged into a drain pape 24 mounted in the bottom wall.

A cylindrical processing drum 25 having

circular end plates

26 and 27 is mounted for rotation within the processing chamber 18. The drum 25 is rotated about its horizontal longitudinal axis by means of two axially aligned

shafts

28 and 29 which are rigidly secured respectively to the

end plates

26 and 27. The

shafts

28 and 29 are journaled respectively in the

end walls

17 and 12 by means of bearings 30. Shaft 28 is coupled to a conventional power unit 20 which serves as means for driving the drum 25 continuously in the direction of the arrow 31.

The drum 25 is provided with an elongated opening 32 in its periphery for access to the interior of the drum. The longitudinal margin of the opening is defined by two

parallel rims

33 and 34, which extend lengthwise along the longitudinal axis' of the drum between the

end plates

26 and 27. As better illustrated in FIGS. 3 and 4 the rim 33 is provided with a flared lip 35 hereinafter referred to as the scooping lip which is of any suitable shape whereby processing solution is scooped up when the drum rotates, as hereinafter described.

The apparatus 10 of the invention further includes an open solution tray 36, preferably shaped hemi-cylindrically, comprising an arcuate bottom wall 37 and end

walls

38 and 39.

As better illustratedin FIGS. 3 and 4 the arcuate bottom wall 36 of the tray 36 is contoured to conform with the peripheral surface of the cylindrical drum 25 and is positionted close to the surface of the drum 25. The tray 36 is pivotally mounted and is movable between an operative position as illustrated in FIG. 4 and an inoperative or dumping position for discharging solution as illustrated in FIG. 3.

In the preferred embodiment the

end plates

38 and 39 are journaled respectively, by means of suitable bearings, about the drum shafts 28 and '29. The tray may be dumped manually or alternatively, a conventional hydraulic power piston assembly (not shown) may be utilized to dump the tray automatically. Any suitable d'etent means (not shown) may be provided for releasably holding the tray in the operative or inoperative position.

Two L-shaped

beams

40 and 41 are mounted respectively on the

side walls

14 and 13 of the housing and extend horizontally along the length of the housing. The bottom wall 37 of the tray 36 is provided with two rims 42 at the top of the tray which extend outwardly from each side of the tray and which rest against the

beams

40 and 41 when the tray is in the operative position as illustrated in FIG. 4. The beam 40 is provided with a leg 43 which slopes downwards towards the tray 36 and which serves as a flume or trough.

The processing solutions are introduced intothe tray 36 by means of a distribution pipe 44, which extends horizontally along the length of the tray and which is positioned above the flume 43 as illustrated in FIGS. 3 and 4. The pipe 44 is closed at both ends and a series of perforations 45 are positioned in its bottom wall and axially spaced along its length. A supply pipe 46 is coupled to pipe 44 at the mid-point of its length. It will be apparent that solutions introduced through the supply pipe 46 will flow along the length of the distribution pipe 44 and will be discharged through the perforations 45 resulting in a uniform flow of solution onto and along the length of the flume 43. Since the flume 43 discharges the solutions into the tray 36 the operation of filling the tray results in a uniform flow of processing solution along the entire length of the tray. The solutions maybe supplied to the inlet pipe 46 from any suitable dispensing system (not shown).

The features for securing the photographic material to the apparatus will now be described in relation to the processing of paper prints. The longitudinal opening 32 extending along the length of the drum 25 provides access to the interior of the drum. The prints are placed in the drum through the opening 32 and since the prints are capable of being flexed they may be bent to conform to the inside curvature of the drum. In the preferred embodiment as illustrated in FIGS. 3 and 4 one or more adjustable bars 47 are detachably fixed to the inside periphery of the drum and extend along the length of the drum on an axis parallel to the longitudinal horizontal axis thereof.

The bar 47 is preferably detachably secured to the interior of the drum by utilizing any suitable adhesive tape (not shown) which adheres to the bar and the drum surface and which can be readily removed to reposition the bar to accommodate varying size of prints. The transverse section of the bar 47 is provided with grooves 48 on opposite edges thereof and similar grooves 48 are provided on the interior side of the

rims

33 and 34. It will be readily apparent that paper prints A and B may be positioned in the drum so that their respective edges fit into the grooves 48.

In a typical embodiment of the invention the drum is about twleve inches in diameter and about forty two inches long. With the bar 47 positioned as illustrated in FIG. 3, a drum with these dimensions is capable of handling four standard X 16 inch prints. As illustrated in FIG. 1, two pairs of prints A and B are positioned side by side along the length of the drum.

It will be apparent to those skilled in the art that by varying the position of the bar 47 and/or utilizing a number of such bars that a drum of fixed dimensions may be utilized to process different size prints.

It is understood that the means for securing the prints to the interior periphery of the drum is not limited to the use of the bars 47. As an alternative, it has been found in practise that the edges of the prints may be taped directly to the drum by means of suitable adhesive tapes (not shown).

The operation of the apparatus will now be described for processing paper prints. In the developing process it is necessary that the prints be treated with a succession of treatment liquids. These liquids are delivered to and removed from the solution tray during each treatment stage at predetermined points in the operating cycle.

The prints are first secured in the drum as aforementioned in such a manner that the emulsion side of the paper faces towards the axis of rotation of the drum, i.e., the emulsion side faces away from the inside surface of the drum.

The drum is then rotated at a constant speed by means of the power unit 20, preferably in the range to rpm, and the drum is continuously rotated at this speed throughout the entire operating cycle.

A predetermined quantity of the first treatment solution is then supplied to thetray 36 from the supply pipe 46. As the solution fills the tray it will be apparent that the scooping lip 35, rotating with the drum and sweeping past the inside periphery of the bottom wall 37, will scoop up the solution and cause the solution to enter the drum.

solution is introduced into the tray. The foregoing cycle is then repeated and the prints treated with a succession of treatment liquids as required by the particular development process.

As aforementioned the use of the flume 43 and the elongated distribution pipe 44 results in the supply of treatment solution along the entire length of the solution tray. It will be apparent that during the filling operation, the foregoing feature will result in the processing solution being supplied to the inside of the drum 25 along its entire length. Thus, the prints in the drum will be uniformly treated since the solution contacts the prints along their entire length substantially at the same time. This feature promotes efficient processing of the prints.

Further, it will be apparent that by spacing the drum surface close to the inside surface of the tray, only a minimum and controlled amount of treatment solution is required to maintain the required level of solution in the drum. Thus, any wastage of solution is kept to a minimum and full utilization of the solution in contacting the prints is achieved without using excessive amounts of solution. This results in savings due to the smaller amount of solution required as compared to apparatus in the prior art.

In order to process photographic film, as aforementioned, it is necessary that both the emulsion side and the side opposite to the emulsion side be treated with the solution. A preferred embodiment for processing film with the apparatus of the present invention is illustrated in FIG. 5. A flexible spacing member 49 is first inserted in the drum and contacts the inside surface of the drum. The spacing member 49 is preferably in the form of a plastic grid or open lattice. The film is then placed in the drum so that it contacts the grid and is held in spaced apart relation from the inside periphery of the drum 25. The film may then be processed by carrying out steps similar to those for processing paper prints as aforementioned. In order to improve solution contact in the area of the open grid 49 for processing the surface of the film which contacts the grid, the rim 33 may be provided with a second scooping lip 50 in It has been found that after a predetermined amount drum at a level as indicated in FIG. 4. Under these conditions the paper prints are continuously passedthrough the liquid and this results in efficient surface contact of the emulsion side of the print with the treating solution.

After a predetermined time the solution tray 36 is then tilted as aforementioned and the solution in the tray discharged into the bottom of the housing. It will be apparent that when the tray is in the inoperative or dumping position as illustrated in FIG. 3 that any solution in the rotating drum will also be discharged through the elongated opening 32 and into the bottom of the housing. These spent solutions are then discharged through the drain pipe 24.

The solution tray 36 is then returned to the operative position as illustrated in FIG. 4 and a second treatment addition to the scooping lip 35 as better illustrated in FIG. 5. As the drum 25 rotates the second scooping lip 50 directs solution into the space between the inside drum wall and the film which is defined by the open grid member 49.

The processing drum 25 and the housing may be fabricated from any suitable material such as metal or plastic.

A feature of the invention resides in the use of an enclosed rectangular housing serving as the processing chamber which is readily adaptable for maintaining uniform temperature of the treatment solution in the drum and solution tray. The housing may be fabricated from insulative plastic and the air within the cabinet maintained at a fixed temperature by means of suitable air heaters and circulating fans (not shown).

The apparatus of the present invention or parts thereof is readily adaptable for use in both manual or automatic operations. For example, the solutions may be supplied to the supply pipe 46 from a solution sink (not shown) which is filled manually or alternatively from a system incorporating separate solution tanks (not shown).

Further, the dispensing system may include automatic controls for supplying metered amounts of solution at predetermined times and means operating in conjunction with the dispensing system for tilting the solution tray automatically (not shown).

lt'will be apparent from the foregoing description of the operation of the apparatus of the present invention that there is provided consistency in treatment of the film between successive stages in the process. Such consistency is a prerequisite in achieving efficient results in the processing of photographic material. A repetition of the same events in each treatment stage is accomplished as aforesaid, by uniform supply of solution along the entire length of the processing drum at the same time, effective control of the amount of solution in the precessing drum and uniform surface contact between the solution and the prints.

Although the invention has been described with reference to the details of a preferred embodiment, it is to be appreciated that the invention is not limited to all of these details. It is rather to be considered as of a scope commensurate with the scope of the subjoined claims.

What I claim is:

l. A processing drum for use in apparatus for processing exposed sheets of photographic material including a tray for containing treatment solution comprising; a cylinder having spaced apart circular end plates and provided with an elongated opening positioned in the periphery of the cylinder for access to the interior of the said drum, the said opening having two parallel rims extending along the length of the periphery of the cylinder between the said end plates, an outwardly projecting scooping lip mounted on one of the said rims, means for holding the said sheets on the inside periphery of the said cylinder, shaft means for rotating the cylinder about its longitudinal horizontal axis, whereby when the said cylinder is rotated the said scooping lip supplies the said treatment solution from the said tray to the inside of the said cylinder, thereby bringing the surface of the said sheets into contact with the said solution.

2. Apparatus for processing exposed sheets of photographic material comprising:

a. a horizontal cylindrical drum having an elongated opening extending over a sufficient arc of the periphery of the drum to provide access to the interior of the said drum for loading of the said sheets into the drum;

b. said opening being defined by first and second parallel rims extending along the length of the periphery of the drum;

0. an outwardly projecting scooping lip mounted on said first rim;

d. means for holding the said sheets on the inside periphery of said drum;

e. means for rotating said drum about its horizontal longitudinal axis;

f. a substantially hemi-cylindrically shaped tray for containing treatment solution, having an arcuate bottom wall positioned near the outside periphery of the drum;

g. means for supplying treatment solution to the said tray during continuous rotation of said drum;

' h. drain means for receiving spent treatment solution and;

i. means pivotally mounting said tray for movement of said tray during continuous rotation of said drum between a first position in which the said treatment solution is brough into contact with the said scooping lip and a second solution discharging position;

whereby with the tray in the first posit-ion, the scooping lip supplies the treatment solution to the inside of the drum, thereby bringing the surface of the sheets into contact with the solution and when the tray is moved to the second position the solution is discharged from the drum and tray into the drain means. I

3. Apparatus as defined in claim 2 wherein the said sheets of photographic material are bent to conform to the curvature of the inside wall of the said drum.

4. Apparatus as defined in claim 3 further comprising means disposed between the said sheets and the said inside wall for maintaining the said sheets in spaced apart relation to the said inside wall.

5. Apparatus as defined in claim 4 wherein the said means disposed between the said sheets and the said inside wall comprises a flexible grid having an open lattree.

6. Apparatus as defined in claim 5 wherein the said drum is provided with a second scooping lip for supplying fluid between the said sheets and the said inside wall.

7. Apparatus as defined in claim 2 wherein the said sheets of photographic material are bent to conform to the inside wall of the said drum and wherein the said means for holding the said sheets includes one or more bars detachably fixed to the inside periphery of the drum and extending along the length of the drum on an axis parallel to the longitudinal axis thereof, the edges of the said sheets being held on the said bars.

8. Apparatus as defined in claim 7 wherein the said bars are provided with grooves extending longitudinally along the length thereof, the said first and second parallel rims being provided with complimentary grooves on the inside of the drum, the edges of the said sheets being held in the grooves of said bars and said rims.

9. Apparatus as defined in claim 2 wherein the said means for supplying treatment solution to the said tray comprises; an elongated distribution pipe positioned above and extending along the length of the said tray, the said pipe having a series of perforations positioned in its bottom wall and axially spaced along its length, the said pipe being closed at both ends and having a solution supply conduit coupled to the mid-point of its length.

10. Apparatus as claimed in claim 2 further comprising: 7

j. an elongated horizontal housing enclosing said horizontal drum, said housing having an elongated opening; and

k. a lid for sealing said last mentioned opening.

11. Apparatus as claimed in claim 2 wherein said scooping lip contacts said arcuate bottom wall of said tray during a portion of each revolution of the drum.

12. Apparatus as claimed in claim 2 wherein said drum has a non-removable end plate at both ends, thereby substantially enclosing both ends of the drum.

13. Apparatus for processing exposed sheets of photographic material comprising:

. a first scooping lip mounted on said first rim; means for holding the said sheets on the inside of said drum adjacent the inside wall of the drum;

. means for rotating said drum about its horizontal longitudinal axis;

. a substantially hemi-cylindrically shaped tray for containing treatment solution, having an arcuate bottom wall positioned near the outside periphery of the drum;

means for supplying treatment solution to the said tray during continuous rotation of said drum;

at least one further scooping lip mounted on said drum for supplying fluid between said sheets and said inside wall;

i. drain means for receiving spent treatment solution and;

j. means pivotally mounting said tray for movement of said tray during continuous rotation of said drum between a first position in which the said treatment solution is brought into contact with the said first scooping lip and a second solution discharging position;

whereby with the tray in the first position, the said first scooping lip supplies the treatment solution to the inside of the drum, thereby bringing the surface of the sheets into contact with the solution and when the tray is moved to the second position the solution is discharged from the drum and tray into the drain means.

Claims

1. A processing drum for use in apparatus for processing exposed sheets of photographic material including a tray for containing treatment solution comprising; a cylinder having spaced apart circular end plates and provided with an elongated opening positioned in the periphery of the cylinder for access to the interior of the said drum, the said opening having two parallel rims extending along the length of the periphery of the cylinder between the said end plates, an outwardly projecting scooping lip mounted on one of the said rims, means for holding the said sheets on the inside periphery of the said cylinder, shaft means for rotating the cylinder about its longitudinal horizontal axis, whereby when the said cylinder is rotated the said scooping lip supplies the said treatment solution from the said tray to the inside of the said cylinder, thereby bringing the surface of the said sheets into contact with the said solution.

2. Apparatus for processing exposed sheets of photographic material comprising: a. a horizontal cylindrical drum having an elongated opening extending over a sufficient arc of the periphery of the drum to proVide access to the interior of the said drum for loading of the said sheets into the drum; b. said opening being defined by first and second parallel rims extending along the length of the periphery of the drum; c. an outwardly projecting scooping lip mounted on said first rim; d. means for holding the said sheets on the inside periphery of said drum; e. means for rotating said drum about its horizontal longitudinal axis; f. a substantially hemi-cylindrically shaped tray for containing treatment solution, having an arcuate bottom wall positioned near the outside periphery of the drum; g. means for supplying treatment solution to the said tray during continuous rotation of said drum; h. drain means for receiving spent treatment solution and; i. means pivotally mounting said tray for movement of said tray during continuous rotation of said drum between a first position in which the said treatment solution is brought into contact with the said scooping lip and a second solution discharging position; whereby with the tray in the first position, the scooping lip supplies the treatment solution to the inside of the drum, thereby bringing the surface of the sheets into contact with the solution and when the tray is moved to the second position the solution is discharged from the drum and tray into the drain means.

5. Apparatus as defined in claim 4 wherein the said means disposed between the said sheets and the said inside wall comprises a flexible grid having an open lattice.

10. Apparatus as claimed in claim 2 further comprising: j. an elongated horizontal housing enclosing said horizontal drum, said housing having an elongated opening; and k. a lid for sealing said last mentioned opening.

13. Apparatus for processing exposed sheets of photographic material comprising: a. a horizontal drum having an elongated opening extending over a sufficient arc of the periphery of the drum to proviDe access to the interior of the said drum for loading of the said sheets into the drum; b. said opening being defined by first and second parallel rims extending along the length of the drum; c. a first scooping lip mounted on said first rim; d. means for holding the said sheets on the inside of said drum adjacent the inside wall of the drum; e. means for rotating said drum about its horizontal longitudinal axis; f. a substantially hemi-cylindrically shaped tray for containing treatment solution, having an arcuate bottom wall positioned near the outside periphery of the drum; g. means for supplying treatment solution to the said tray during continuous rotation of said drum; h. at least one further scooping lip mounted on said drum for supplying fluid between said sheets and said inside wall; i. drain means for receiving spent treatment solution and; j. means pivotally mounting said tray for movement of said tray during continuous rotation of said drum between a first position in which the said treatment solution is brought into contact with the said first scooping lip and a second solution discharging position; whereby with the tray in the first position, the said first scooping lip supplies the treatment solution to the inside of the drum, thereby bringing the surface of the sheets into contact with the solution and when the tray is moved to the second position the solution is discharged from the drum and tray into the drain means.