US2644384A - Developer for continuous strip of photographic paper - Google Patents

Description

y 1953 v. J. FORGETT 2,644,384

DEVELQPER FOR CONTINUOUS STRIP OF PHOTQGRAPHIC PAPER Original Filed July 24, 1947 4 Sheets-Sheet l BY MN M ATTORNE Y.

O y 7, 1953 v. J. FORGETT 2,644,384

DEVELOPER FOR CONTINUOUS STRIP OF PHOTOGRAPHIO PAPER A 7 TORNEYS July 7, 53 v. J. FORGETT 6 8 DEVELOPER FOR commons STRIP 0F PHOTOGRAPHIC PAPER Original Filed July 24, 1947 4 Sheets-Sheet 3 i; :Ej

INVENTOR.

\xxwx WM ATTORNEYJ J 7, 1953 v. J. FORGETT 2,644,384

DEVELOPER FOR CONTINUOUS STRIP OF PHOTOGRAPHIC PAPER Original Filed July 24. 1947 4 Sheets-Sheet 4 FIG.9

INVENTGR. QM X QQ ATTORNEYJ Patented July 7, 1953 UNITED STATES ATENT OFFICE DEVELOPER FOR CONTINUOUS STRIP OF PHOTOGRAPHIC PAPER Valmore J. Forgett, Ridgefield, N. .L, assignor to Sweco Products, Inc., Ridgefield Park, N. J., a corporation of New Jersey 2 Claims.

This invention relates to apparatus for developing, fixing and washing strips of photographic paper.

Substantial economies can be effected in the commercial printing of photographs by using long strips of photographic paper for printing groups of negatives, and then processing all of the prints in a continuous operation. When completed and dried, the separate prints are out apart and sorted. The apparatus of this invention is a developer, it being understood that a developer includes means for fixing and washing the strip immediately after its development. One object of the invention is to provide an improved developer with guide rollers for reversing the run of the strip as it passes through and between successive tanks of liquid, and to maintain some tension on the strip between successive guide rollers regardless of stretching of the paper while wet.

Another object of the invention is to provide a continuous strip developer with simple and compact power mechanism for driving successive guide rollers and wind-up reels, and with provision for accommodating the speed of a windup reel to the diameter of the strip that is already wrapped around the reel.

Some features of the invention relate to the automatic control of the temperature of the developer, and to coordination of the developer temperature with the speed of the strip and the extent of the tanks through which the strip passes for fixing and washing.

Other features of the invention relate to the construction of the frame of the apparatus. In

the preferred construction, this frame is fabricated from structural sections which hold a row of tanks in assembled relation. The frame includes longitudinal structural elements along opposite sides of the row of tanks, and transverse elements connected with the sides of the frame, but extending beyond the sides of the frame to provide supports for certain parts of the apparatus which must be located outside of the tanks. Still other features relate to the liquid circulating system of the apparatus for maintaining the liquids in the respective tanks in condition for effective and efficient operation, and for maintaining a circulation of water through the washing tanks.

This application is a division of my copend" ing application Serial No. 763,411, filed July 24, 1947, now Patent Number 2,461,419 issued on February 8, 1949.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views,

Figure 1 is a side view partly broken away, showing developer apparatus embodying this invention,

Figure 2 is an enlarged top plan view of a portion of the apparatus shown in Figure 1,

Figure 3 is a sectional view taken on the line 33 of Figure 4,

Figure 4 is a vertical sectional view through the first two tanks and part of the third tank of the apparatus shown in Figure l, the section being taken on a plane parallel to the plane of the drawing in Figure 1,

Figure 5 is an enlarged sectional view-taken on the line 5-5 of Figure 4,

Figure 6 is a greatly enlarged perspective view of one of the clips and drain plates shown in Figure 4,

Figure 7 is an enlarged fragmentary, Vertical elevation of the upper portion of the apparatus shown in Figure 1, but viewing the apparatus from the opposite side,

Figure 8 is an end view of the apparatus shown in Figure 1,

Figure 9 is a view similar to Figure 2, but showing the discharge end of the developer apparatus.

The apparatus shown in Figure 1 comprises a fabricated frame Ill made up of vertical sections l I connected together by longitudinally extending sections l2 and transverse sections 13. Within this frame there are tanks comprising a developer tank !5, three tanks It for fixing solution, and five tanks ll for water.

The paper strip to be developed is wrapped in a reel 20 and supported from brackets 2i at one end of the frame Ill. The strip, indicated by the reference character 23, unwinds progressively from the reel 20, passes over a first guide roller and then downward into the developer tank l5.

Within the developer tank l5, at a predetermined distance irom the bottom of the tank, there is an idler guide roller which is not shown in Figure l, but will be described in connection with subsequent figures of the drawing. The strip 23 passes around the idler roller in the developer tank l5 and thence upward to another guide roller 21. This second guide roller 21 again reverses the run of the strip so that it passes downward into the first one of the tanks it. This first tank It contains a quick fix solution, that is, a chemical solution that will arrest instantly the action of any developer remaining on the paper.

The strip 23 travels around other rollers which cause it to pass downward to a predetermined depth in each tank and then upward around other guide rollers and downward into successive tanks. The second and third tanks [6 are filled with solution for effecting a permanent fixing of the photographs, and the next five tanks I! are filled with water for thoroughly washing the strip before it passes over a final guide roller 29. From this final guide roller 29, the strip 23 is wound up on a reel 30, supported from the frame ill by brackets 3|, and driven by power mechanism which will be described in connection with the other views.

Figure 2 shows the roller 25 and its axle 34 supported in bearing blocks 36 and 31. These bearing blocks are supported on the uppermost longitudinally extending frame sections !2 of the apparatus. The roller 25 is of substantially the same width, or slightly wider than the transverse width of the paper strip with which the developer is intended to be used. The transverse width of the tank 15 is greater than the width of the roller 25. The bearing blocks 36 and 3! are connected to their respective supports H! by screws 45.

The axle 34 extends through and beyond the bearing block 35 and is held against endwise movement by a thrust collar M on one side of the bearing block 35 and by the hub of a sprocket 48 on the other side of the bearing block 35. The thrust collar 41 and sprocket 48 are preferably pinned to the axle 34 so as to turn as units with the axle.

Between the tank 15 and the first one of the tanks l there is another guide roller 2! with an axle 5| supported by hearing blocks 35 and El. There is a thrust collar 41 and a sprocket 48 attached to the axle 5!, the construction being identical with that of the axle 34. Between all of the successive tanks of the developer there are similar guide rollers 50.

Midway between the guide rollers 25 and 21 there is a frame 54 with a bar 55 at its upper end. This bar 55 is considerably wider than the remainder of the frame 54, and its opposite ends serve as hangers for supporting the frame 54 from the adjacent longitudinal frame sections i2. Open top sockets 51 are provided in the frame sections I?! for receiving the ends of the bar 55, and there are other frames 54 extending downward into the tanks between all of the subsequent guide rollers of the apparatus.

The frames 54 support idler guide rollers 60 (Figures 4 and 5) near the lower ends of the tanks. These idler guide rollers 60 have flanges 5! for preventing transverse movement of the strip. The advantage of these flanges is that they prevent the strip from becoming displaced on the idler guide roller 60 during the initial threading of the strip, or a leader, through the apparatus.

In the construction illustrated, each of the frames 54 includes vertically extending side channels 52 connected at their upper ends by he bar 55 and connected midway between their ends by tie bolts 63. When threading the strip or leader, the frames 54 are lifted out of the tanks, the strip or leader is extended across between the guide rollers at opposite ends of the tank, and the roller 60 is placed in contact with 4 the top surface of the strip and pushed downward into the tank until the bar 55 at the top of the frame 54 enters into the supporting sockets 5'! which hold the frame 54 in working position. The strip 23 is then located in the tank in the position indicated in Figure 4.

The angle which the downwardly extending run of the strip makes with the upwardly extending run depends upon the depth and the length of the respective tanks. In the water tanks, which are not as wide as the developer and fixing solution tanks, the strip extends downwardly and upwardly at steeper angles. In describing the operation of the guide rollers for reversing the run of the strip, it will be understood that this expression does not denote a change in direction which must amount to but means merely that the direction of the strip is changed by an angle greater than The actual value of the angle depends upon correlations of horizontal and vertical distances between the guide rollers.

Deep tanks have the advantage of reducing the length of the apparatus and locating the guide rollers and the winding and unwinding reels at convenient heights for handling by an attendant when the apparatus is standing on the floor. The deep tanks have the further advanta e that a longer length of strip is immersed at the same time and the strip can therefore travel faster and still have each unit of area immersed for a period suiiiciently long for the desired treatment by the liquid in the tank.

The developer and fixing solution tanks are made longer longitudinally than the water tanks because the strength of the chemicals is affected by their reaction with the emulsion on the paper, and a substantial volume of chemical causes the change in strength to take place more slowly. Water is circulated continuously through the water tanks; and if sufiicient provision is made for circulating and replenishing the developer and fixing solutions, the tanks for those solutions need not be any larger than the water tanks.

In the preferred construction of the apparatus, each of the tanks has an inlet pipe 64 (Fig. 3) opening into the tank near the lower end of the tank. Each inlet pipe 64 has an upwardly extending portion that rises to a level above the liquid level in the tank, and that connects with a source of supply of the kind of liquid used in the particular tank with which that inlet pipe connects. A supply pipe 66 leading to the liquid supply source connects with the upper end of the inlet pipe 64. Near the upper end of each tank there is a drain comprising an overflow pipe 68 opening through the side of the tank at the intended level of the liquid in the tank. This liquid level is indicated in Figure 3 by the dotted line 75. Each of the overflow pipes 68 opens into a common drain pipe l2 (Fig. 1) that rests on extensions of one of the transverse frame sections 13. This drain pipe 12 is held in place on the frame by U-bolts "l5, and it has an outlet 16 near its lower end leading to the sewer.

The inlet pipe 64 leadin to the developer tank I5 is supplied with developer from a reservoir. The developer runs into the pipe 64 at a relatively slow rate, but suflicient to maintain the required strength of the developer in the tank. Similarly, fixing solution for the quick fix in the first of the tanks I6 is supplied from a reservoir to the pipe 64 that leads to the first of the fixing solution tanks 16. Similarly the other tanks 16 are supplied with fixing solution and at rates to maintain the strength of the chemicals in the fixing tanks. Water for the final tanks is similarly supplied to the bottoms of the tanks through pipes 64 and from a watersupply line that connects with all of the water tank inlets and at a rate fast enough to maintain the necessary purity of the washing water.

Contamination of the liquid in one tank by liquid carried on the strip from the previous tank is prevented by drain plates 80 (Figs. 4 and 6). Each of these drain plates is attached to a clip having a center portion 82 that bridges the upper ends of the adjacent sides of successive tanks, and has downwardly extending portions 83 that extend along the inside walls of the successive tanks for a limited distance to hold the clips in place. Each drain plate 80 is attached to its clip in a position that gives the drain plate a substantial slope when the clip is in position on the upper edge portions of the tank Walls. These clips are placed on the tanks in such a direction that the drain plates 80 slope toward the tank from which the paper stri is emerging as it approaches the guide roll above the drain plate.

The guide rollers 2'! are far enough above the liquid. levels in the tanks to permit a substantial portion of the liquid on the paper to run back into the tank from which the paper emerges.

What liquid is squeezed off onto the guide rollers 2'5 by contact of the strip with the guide roller drips from the bottom of the guide roller onto the drain plate 89 from which the liquid runs back into the tank from which it came.

In order to obtain uniform results, the apparatus controls both the temperature of the liquid in the developer tank and the length of time that the paper is exposed to the action of the developer. The temperature control is obtained by supplying a tortuous run of refrigeration tubing 81' (Figs. 3 and 4) below the level of the liquid in the developer tank I5. Heat insulation is provided around the tank I5. This insulation includes panels 89 covering both the front and back of the tank i5, and other panels 88 that cover the sides of the tank. The side panels 88' preferably extend for substantially the full length of the apparatus to cover all of thetanks and give the equipment a neater appearance. The ends of the tubing 81 extend through openings in a side wall of the tank I5, near the bottom of the tank, and this tubing is connected with a refrigeration unit 89 (Fig. 8).

Additional refrigerant is supplied by the unit 89 to the refrigeration tubing 81 wheneve the temperautre of the liquid in the tank I5 exceeds a predetermined limit. This automatic temperature control can be effected by means of a thermostat, but is preferably obtained by using the pressure variation with change of temperature to start and stop the refrigeration unit in accordance with the practice commonly employed for domestic refrigerators.

The length of time that the paper strip is exposed to the action of the developer depends upon the speed of rotation of the guide rollers. The rollers 25 and 2'! are driven by a sprocket chain 9! (Fig. 7). This chain, which extends across all of the sprockets 48 on the near side of the apparatus in Figure '7, is driven by a sprocket 92 on the low speed shaft of a gear reduction unit 93. A pulley 94 on the high speed shaft of the gear reduction unit is rotated by a V-belt 95 from a variable speed pulley mechanism 95.

Power is supplied to the'variable speed pulley mechanism 96 from an electric motor 91 and through a V-belt 98. The gear reduction unit 93, the variable speed pulley mechanism 96 and the motor 91 are all connected to and supported by a" shelf or platform I00 that rests upon transverse frame sections I3 extending from one side of the apparatus beyond the vertical sections II, as most clearly shown in Figure 8. The variable speed pulley mechanism 96 includes two pulleys IOI and I02 carried on an axle I03. This axle I03 is supported by a frame that is connected by a pivot I05 with supports I06 that are attached to the platform I00.

The pulleys WI and I02 have their adjacent faces on opposite sides of a common center flange which is movable within a limited range toward and from the other flanges of these pulleys to vary the width of the grooves of the respective pulleys, and to thus increase or decrease the effective diameter of the pulley faces on which the V-belts and 98 (Fig. '7) run. For example, if the frame supporting the axle I03 is moved to the right about the pivot I05 in Figure 7, the tension of the belt 98 is increased, and that of the other belt 95 is decreased. This causes the V-belt 98 to be forced more deeply into the groove of one of the pulleys, widening the groove and forcing the intermediate flange, that is common to both pulleys, to move toward the other belt 95 so that the other belt with the relaxed tension rides higher in the narrowed groove of the pulley I02. This adjustment causes the motor 91 to drive the sprocket 94 at higher speed.

The pivots I05 are provided with sufiicient friction, or other means are used, for holding the frame that supports the axle I93 in its various adjusted positions. By means of this speed control very accurate adjustment can be obtained for the speed of rotation of the guide rollers, and the length of time that the paper is exposed to the action of the developer is accurately regulated.

The guide rollers 25 and 21 over which the strips pass are preferably crowned in order to keep the strips centered on the guide rollers as the strips pass through the machine. The idler rollers 60 may also be crowned or the flanges BI can be relied upon to keep the strips centered on these guide rollers 50.

The driven guide rollers 25 and 21 are preferably of progressively larger diameter between successive tanks. Since the rotary speed of all of these guide rollers is the same, in the construction illustrated, the larger diameter gives the successive guide rollers progressively higher peripheral speeds to compensate for stretch in the paper strip and to maintain some tension on the strip within the tanks. The faces of these guide rollers are preferably rubber and smooth enough to allow some slipping of the rollers on the paper before the tension becomes great enough to tear the paper. Some tension is important because any play or sagging of the strip in the tanks would be cumulative and might result in rubbing and scratching of the paper on stationary portions of the apparatus. Other means can be provided for obtaining the progressively higher peripheral speed from the guide roller to the next.

Beyond the last guide rollers 29 (Fig. 9) there are centers I23 for holding the reel 30 on which the developed paper strip is wound. One of the centers I23 is preferably fixed and rigidly secured to the right-hand bracket 3| extending from the fixed frame of the apparatus. The

other center I23 is attached to the inner end of a shaft I28 that rotates in a bearing I 29. This shaft I28 is movable longitudinally in the bearing I 29 against the pressure of a spring I39. The bearing I29 is fixed to the adjacent bracket 3| extending from the fixed frame of the apparatus, and the spring I30 is compressed between this bracket 3| and a flange I34 attached to the end of the shaft adjacent the center I23.

A pin I35 fits into a recess in the reel 39 to transmit rotary motion of the shaft I28 to the reel. In order to turn the reel 30 at different speeds in accordance with the diameter of the paper strip wound on the reel at any given time, a friction drive is provided for rotating the shaft I28. This friction drive comprises a coil spring belt I 38 which passes over a pulley I39 on one end of the shaft I28, and another pulley I40 on the same shaft with the guide roller 29.

With the pulleys I39 and I40 of the same diameter, the rotary speed of the shaft I28 is equal to that of the guide roller 29. The reel 30 is made with a diameter not less than that of the final guide roller 29 so that the length of the paper strip wound on the reel 30, with each revosution of the reel, is equalto the length of the strip that comes from the apparatus over the drivenv guide roller 29. As the diameter of the strip wound on the reel 39 increases, the rotary speed of the reel must decrease. This is possible without imposing excessive tension on the strip because the spring belt I38 can slip easily on the pulleys I39 and I49. The tension of the spring belt I 38 is chosen so as to supply just enough friction to cause the paper strip 23 to wrap up on the reel 39 with the desired pressure between the successive convolutions.

The preferred embodiment of the invention has been illustrated and described, but changes and modifications can be made and some feature of the invention can be used alone, or in different combinations without departing from the invention as defined in the claims.

I claim as my invention:

1. In a developer for paper strips including a plurality of tanks for liquids that are used to develop, fix and wash the strip, the combination with said tanks of rollers over which the strip passes in traveling successively through the liquids in the different tanks, said rollers including a roller within each tank in position to reverse the run of the strip in the tank, other rollers located between the tanks in position to reverse the run of the strip between successive tanks, said other rollers between successive tanks being of progressively larger diameter toward the strip discharge end of the developer to compensate for increased length caused by stretching of the strip while wet, and said other rollers having smooth peripheral surfaces that slip on the surface of the wet paper when the paper tension reaches a predetermined value, which value is substantially less than the tension required to tear the paper, common power driving means, and mechanism through which the common power driving means rotates said other rollers at equal angular speeds.

2. Apparatus for developing, fixing and washing long strips of photographic paper in a continuous operation, said apparatus including a series of tanks through which the strip passes, a roller between each tank and the next for changing the direction of the run of the strip, each roller having a smooth peripheral surface that slips on the surface of the wet paper when the paper tension reaches a predetermined value, which value is substantially less than the tension required to tear the paper, an idler roller located down in each of the tanks and around which the strip passes to reverse its run in the tank, and common power means connected with the rollers between the successive tanks and driving said rollers at successively greater peripheral speeds to maintain some tension on the strip passing to and from the idler rolls.

VALMORE J. FORGETT.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 525,849 Mackusick Sept. 11, 1894 1,141,484 Javault June 1, 1915 1,567,051 Thompson June 1, 1926 1,967,889 Kitroser July 24, 1934 2,248,333 Burbank July 8, 1941 2,346,530 Wyllie, Jr. Apr. 11, 1944 2,461,419 Forgett Feb. 8, 1949

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