US2524818A - Light-sensitive print development apparatus - Google Patents

Description

Oct. 10, 1950 J. w. M HUGH LIGHT SENSITIVE PRINT DEVELOPMENT APPARATUS Filed June 25, 1946 3 Sheets-Sheet l Oct. 10, 1950 J. w. MC-HUGH 2,524,818

LIGHT SENSITIVE PRINT DEVELOPMENT APPARATUS Filed June 25, 1946 3 Sheets-Sheet 2 Oct. 10, 1950 J. w. MC-HUGH 2,524,818

LIGHT SENSITIVE PRINT DEVELOPMENT APPARATUS Filed June 25, 1946 IS Sheets-Sheet 5 I INVEN TOR. 52% h ww z chambers is slow and inefiicient.

image on the print.

Patented Oct. 10, 1950 LIGHT-SENSITIVE PRINT DEVELOPMENT APPARATUS Joseph W. McHugh, Pittsburgh, Pa.

Application June 25, 1946, Serial No. 679,177

This invention relates to the art of developing or fixing images obtained from light-sensitive paper through exposure to light under a pattern such as drawings or tracings or print on translucent or transparent material or of images obtained from a pattern on an opaque base by reflex copying and more particularly it relates to the process for controlling the development or fixation of the prints and apparatus for contacting the prints with the developing or agents and furthermore to obtain prints that are dry after development or fixation.

For the sake of convenience and since devel" opment of prints in all processes referred to is tantamount to fixation development will hereafter be referred to as fixation.

In each instance the fixing agent, regardless of whether or not it forms a part of the dye, may be applied to the light-sensitive print in the form of a vapor. The simplest manner to produce the fixing agent in vaporized form is by heating the agent or a solution of the agent. The manner of applying and controlling the amount of vapor to be used was heretofore accomplished by subjecting the light-sensitive print to an atmosphere of the vaporized fixing agent by either placing the prints into a chamber filled with such vapors or by movin prints over a screen separating the chamber from the prints. Both methods ofier inadequacies. Fixation of prints in vapor filled It produces prints that are damp and loaded with obnoxious ammonia vapors. The other known method whereby prints are moved over a metal screen by means of a belt causes prints to stick in the fixing equipment. The moist vapors are absorbed by the prints making them limp and too soft to allow them to slide satisfactorily over metal screens. Continuous friction between the prints and the screen also tends to clog the holes of the screen toprevent satisfactory contact of the porous member having a porous surface for receiving a limited amount of fixing agent fluid to prevent the saturation of the porous member .and maintain its porous surface dry for the receptionof the light sensitive surface of prints v permitting the vapors of the fixing agent fluids within the porous member to develop and fix the This enables an accurate control of the amount of vapors of fixing agent to the print and when supplemented by heat not 1 Claim. (01. 95-89) 2 only increases the expulsion of the vapors from the porous member but also increases the action of the fixing agent on the light sensitive surface of the print.

The principal object of this invention is a novel apparatus for fixing light-sensitive prints devoid of the insufiiciencies inherent in presently known method and equipment.

Another object of this invention is the provision of a novel apparatus for metering the quantity of fixing agent applied to an exposed lightsensitive layer in fixing the image thereon.

Another object is the provision of a novel apparatus for controlling the timing of the dispensation of the fixing agent in developing the image of an exposed light-sensitive layer.

Another object is the apparatus for increasing the effectiveness of a fixing agent in developing a. light-sensitive print.

Another object is the apparatus for accelerating the development of a light-sensitive print by the manner of handling the fixing agent.

Another object is the provision of apparatus for developing a light-sensitive print that is relatively dry when completed.

Another object is the provision of apparatus which regulates and controls the developing strength of a fixing agent in developing a print.

Another object is the provision of apparatus for positively delivering a metered amount of a heated vaporized fixing agent in developing a light-sensitive print.

Other objects and advantages appear in the following descriptions and claim.

Practical embodiments illustrating the principles of this invention are shown in the accompanying drawings wherein:

Fig. 1 is a top plan View of the developing machine comprising this invention with the housing in section showing-the motor drive.

Fig. 2 is an end elevation of the machine shown in Fig. 1.

Fig. 3 is a sectional View of the developing machine comprising this invention showing the use of an electric heater as a source of heat.

Fig. 4 is a sectional View of a modified form of developing machine using infra-red lamps as the source of heat.

Fig. 5 is a sectional View of modifiedform of developing machine using fuel as a source of heat.

Fig. 6 is a detailed View of a wick application.

Referring to Figs. 1 to 3 of the drawin s the combination developing and drying machine comprises a base I on which is supported the clay, porcelain or china or other suitable materials. The drum must be sufficiently large in diameter and of such thickness to permit its absorption in liquid form of the proper amount of volatile fixing agent to develop a print, which liquid fixing agent is volatilized and driven by heat from the drum to the print to develop the latter. If this drum is made of a flexible material such as felt or woven fabric, it must be mounted on a rigid frame or cylinder which in turn is journaled in the end walls 3 and 4. If a rigid material is employed hubs on the ends thereof may be employed to support the porous metal or porcelain in the end walls 3 and 4. With a metal or clay drum 5 the end edges and inner surface may be left porous or sealed by glazing or other form of sealing agent.

The roll 5 is engaged for approximately seveneights of its perim tral surface by a section of the continuous belt 8 which may be made of any suitable material that is flexible and can withstand the fixing agent chemicals employed in the presence of heat. The belt 8 is held against the surface of the drum 5 by the spaced guide rollers IE! and II which are journaled in the bearings I2 and I2 respectively. The roller ID engages the belt 8 as it comes in contact with the drum 5 and the roller Ii engages the belt 8 as it leaves the drum 5. The bearings I2 and I3 of these guide rollers ID and II should be adjustable so as to insure pressure contact by these guide rollers through the belt 8. Intermediate the guide rollers ID and II the belt 8 is supported by the idler rollers I4, I5 and I6 which are journaled in the bearings I'I, I8 and I9 respectively. spaced relation from the belt covered drum 5. The bearings of these idler rolls may be adjustable radially of the drum 5 to take up the slack in the belt 8. To remove or replace the belt 3 the end wall 4 may be unfastened from the base i I and slid outwardly carrying the bearings. The belt may then he slipped over the rollers as shown in Fig. 3 and the shafts of the rolls reinserted in their bearings when the wall 4 is replaced.

The shaft of the guide roll ll extends beyond the bearing carried by the end wall 3 and is provided with the pulley arranged to receive the belt 2: which also engages the pulley 22 on one end of the shaft 23 journaled in the bearin 24. The other end of the shaft 23 has the friction transmission wheel 25 the face of which is engaged by the friction clutch pinion 25 having a splined connection on the shaft 2'! which is disposed at right angles to the shaft 23. The shaft 27 is journaled in spaced bearings carried by the frame 25. Spaced cap bearings 30 and 3I are provided on top of the frame 28 in which the adjusting shaft 5.52 is journaled. Intermediate the cap bearing the shaft 32 is threaded as indicated at 33 to receive the complementary threaded bore of the yoke 34. Each arm of the yoke 34 is bifurcated to engage the hubs 35 of the pinion 25. Thus by turnin the hand wheel 36 the yoke 34 moves the pinion 26 axially of the splined shaft 21 and across the face of the These idler rolls maintain the belt in friction transmission wheel 25 and thus chan es the speed of rotation of its shaft 23. One end of the shaft 2! is provided with the coupling 31 that connects with the output shaft 38 of the speed reducer 40 driven by the motor M, which may be of the variable speed type. Thus the guide roller I I may be driven at any desired speed and since the belt 8 passes around this guide roll it is employed to drive the drum 5 and all of the other rolls in which it comes in contact.

A pair of spaced throats are provided for inserting and withdrawing the prints from between the belt and the drum. The insertin or feeding throat 42 is formed by extending a portion of the casin 43 inwardly for the full length of the machine and has the feathered edge that engages the belt 8 with light pressure as it rolls around the roll III. The bottom surface of the throat 42 is defined by a similar featheredged piece 44 which engages the drum 5 just short of where the belt 8 comes in contact with the drum. These feathered edges guide the prints between the porous drum and the belt 8. If the machine were driven backwards these feather edges would strip either member of the print.

A similar discharge throat 45 is made by the featheredged strips 46 and 41, their normal function being to strip the print if it is not already free as it comes from between the drum 5 and the belt 8 at the tangential points between the driving guide roll I I and the drum 5.

As shown in Figs. 2 and 3 the normal direction of rotation of the drum 5 is counterclockwise as shown by the arrows, and the feeding throat 42 is adjacent but above the discharge throat 45 in the front of the machine. However in Figs. 4 and 5 the rolls and the casing are arranged to place the feeding throat 42 on one side of the machine and the discharge throat 45 on the other side. In these views the belt 8 engages the drum 5 during different degrees of rotation of the latter which may be compensated for by the speed of rotation of the drum 5 or by employing a drum the porosity of which provides for the absorption of more of the fixing agent. Also in Figs. 4 and 5 one less idler roll is employed.

In Figs. 3, 4, and 5 three different sources of heat are illustrated. In Fig. 3 an electric heating coil 5! is supported on the insulated drum 5I which in turn is carried by the brackets 52 mounted on the shaft 53 on which the drum 5 is rotatably supported. The lead wires 54 and 55 for supplying electricity to the heating coil are carried through the stationary shaft 53. The fixing agent is supplied to the elongated trough supported between the throats 42, 45 and extending the full length of the drum 5. An applicating roller 51 is journaled at its ends in the end plates 3 and 4 and engages the whole of the face of the drum 5. When the trough 5G is maintained full of the liquid fixin agent approximately one-third of the applicator roll is immersed in the liquid and as the drum is rotated the applicator roller transfers the fixing liquid to the drum 5. If the machine is not rotating there is no transfer of the fixing agent and the applicator roll 57 substantially fills the trough 56 preventing any waste of the liquid.

The porous drum 5 being heated by the coil 50 quickly absorbs the liquid that is continuously transferred thereto. The liquid goes into the pores of the drum 5 and when dispersed therein quickly vo-latilizes due to the heat and the vapor is driven back out of the drum into the light sensitive layer of the print as a heated vapor. When Thus when the machine is stopped the fixing agent ceases to be sprayed on the drum.

the pinion 26 is set for the slowest speed as shown in Fig. 2 the spacing is sufiicient to retain the vapors in the wetted .drum until it is about to contact the belt 8. Before the drum 5 has revolved through 180 substantially all of the liquid fixing agent has been volatilized and driven out of the drum into the light sensitive layer of the print. The vapor being heated increases its action in the process of developing the print so between the featheredged guide plate 44 and the belt 8 which is very small.

After the liquid fixing agent has all been volatilized and driven out of the drum the latters continued engagement with the print substantially dries the latter dispersing the heated vapors causing it to lose substantially the greater portion of the chemical odors.

In Fig. 4 the heating coils 50 are replaced by the infra red lamps 58 which are carried by a series of lamp sockets 59 mounted on the bracket 60. In this structure the shaft 53 does not extend through the drum but is replaced by spaced axially aligned gudgeons and the series of brackets 60 are fastened on the rod 6| which in turn 2 is secured to the ends of the gudgeons. With this arrangement the bracket may be properly adjusted to provide the best distribution of heat, the degree of heat being regulated by the voltage of lamps employed.

The porous drum 5 in Fig. 4 is itself immersed in the upwardly open trough-62 for the purpose of picking up the liquid fixing agent. The drum being heated readily absorbs the liquid and it and any fumes that can possibly escape must do 10 is retained therein until the heat of the lamps vaporizes-it driving it-euteintothe lightesensitive layer of the print being developed. Before the print leaves the vicinity of the last lamp the liquid should be completely volatilized from the drum and the heated drum completely dries the print before it leaves the discharge opening 45. The structure of Fig. 5 is similar to that shown in Fig. 4 except a gas burner 63 is employed as a source of heat. The interior of the drum 5 must be vented in this case so that air is available to supply oxygen to burn the gas and a flue to conduct the products of combustion from the combustion chamber 64 which is attached to the burner. The ends of the burner 63 are secured to the ends of the hollow stationary shaft 53 on which the drum 5 is journaled and the shaft is employed to conduct the gas to the burner.

The fixing agent may be pumped under pressure to the line 65, to the header 66, from whence it flows through the branch lines 61 to the fishtail nozzles 68 that direct the fixing agent on the surface of the rotating drum 5. The pump for the fixing agent, which is not shown, may be operated by the motor that drives the drum.

Another mode of conducting the fixing agent to the heated drum 5 is shown in Fig. 6 wherein a longitudinally disposed trough I0 is supported adjacent the drum and is arranged to receive an adequate supply of the fixing agent liquid. This trough is closed and is provided with wick carrying jaws H for the purpose of holding a wick or wicks 12. A portion of the wick is immersed in the fixing agent and the other end extends out between the jaws ii of the trough and engages the surface of the rotary porous drum for the purpose of conducting the fixing agent liquid to the drum.

Four modes of applying the fixing agent to the heated porous drum are shown. Adequate liquid leveling control means may be provided for maintaining the liquid level in the troughs for the roller, the immersion and the wick processes and adjustments of the pump may be provided for controlling the amount of fixing agent supplied in the spraying process. However the most accurate and important control of the amount of fixing agent delivered to the drum is by the choice of the porosity of the drum itself, its temperature and the speed at which it rotates. Thus a drum of definite dimensions having a known porosity is capable of absorbing a fixed quantity of fixing agent by any one of the four modes when traveling at a predetermined speed. Thus a proper amount of fixing agent may be employed to properly develop the print. This materially reduces spoilage due to under developments of the print and. produces a, print uniformly developed.

Iclaim:

A light sensitive print developing apparatus comprising a print engaging rotary driven cylindrical drum having an outer porous surface sufiiciently large and thick to absorb the proper amount of fixing agent to develop the light sensitive surface of a print in less than one revolu tion of the cylindrical drum, applicator means mounted to conduct a limited supply of liquid fixing agent to the porous surface of the rotary cylind-ricahdrum-as itrevelves said-supply eing limited to provide the necessary amount of liquid fixing agent to develop a print in less than one revolution of the drum, and heating means within the cylindrical drum to heat the interior thereof and evolve all the liquid fixing agent into vapor and expel the vapor from the porous cylindrical drum into the light sensitive surface of the print and dry the porous cylindrical drum before it is again wetted by the applicator means on the next revolution.

JOSEPH W. McHUGI-I.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,798,414 Gronau Mar. 31, 1931 1,821,306 Hingst Sept. 1, 1931 1,841,653 Van Der Grinten Jan. 19, 1932 1,953,160 Fuke Apr. 3, 1934 2,240,409 Morse Apr. 29, 1941 2,257,207 Miester Sept. 30, 1941 2,336,875 MacDonald Dec. 14, 1943 2,431,041 Hassler Nov. 18, 1947 FOREIGN PATENTS Number Country Date 305,071 Italy June 26, 1933 411,544 Great Britain June 14, 1934 605,951 Germany Nov. 22, 1934 654,899 Germany Dec. 30, 1937 686,522 Germany Jan. 11, 1940

Images