US3896468A

US3896468A - Apparatus for wet treatment of photographic materials or the like

Info

Publication number: US3896468A
Application number: US472899A
Authority: US
Inventors: Jurgen Muller
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1973-05-25
Filing date: 1974-05-23
Publication date: 1975-07-22
Anticipated expiration: 1992-07-22
Also published as: DE2326679B2; BE815094A; DE2326679A1; FR2231036B3; IT1012353B; DK279474A; NL7406814A; JPS5028835A; FR2231036A1

Abstract

Apparatus for wet treatment of sheets and/or webs of photographic material has a vessel with an overflow opening for a body of liquid in the vessel, and a heating unit having two glass tubes, filaments imbedded in the tubes, a flexible hose which is shrunk onto the tubes and whose ends are clamped to a bridge member above the level of the overflow opening and conductors extending through the ends of the hose and connected to the filaments. The hose prevents the liquid from contacting the filaments and/or conductors in the event of breakage of glass tubes.

Description

United States Patent Miiller 1 Jul 22, 1975 1' APPARATUS FOR WET TREATMENT OF 2,463,386 3/ 949 Hopper 354/299 PHOTOGRAPHIC MATERIALS OR THE 2,811,629 10/1957 Danner 1. LKE 3,663,799 5/1972 McArn 219/523 v 3,737,621 6/1973 Elkins [75] Inventor: Jiirgen Miiller, Munich, Germany 3,796,858 3/1974 Cohn 219/216 X [73] Ass1gnee: ggbggngosch G.m.b.H., Stuttgart, Primary Exdminer Fred L. Braun Attorney, Agent, or Firm-Michael S. Striker [22] Filed: I May 23, 1974 I [21] Appl. No.1 472,899 [57] ABSTRACT Apparatus for wet treatment of sheets and/0r webs of [30] Foreign Application priorilty Data photographic material has a vessel with an overflow Ma 25 1973 German 2326679 opening for a body of liquid in the vessel, and a heaty y ing unit having two glass tubes, filaments imbedded in the tubes, a flexible hose which is shrunk onto the 35439863112232)? tubes and whose. ends are clamped to a bridge mem [58] Fie'ld 299 331' ber above the level of the overflow opening and con- 2l9/2l6 523 1 ductors extending through the ends of the hose and connected to the filaments. The hose prevents the liq- [56] References Cited uid from contacting the filaments and/or conductors in the event of breakage of glass tubes. UNITED STATES PATENTS 2,178,397 10/1939 Larkey 219/523 x 10 Claims 3 Drawing Figures 6 4b 7 Am A 1 a V 1b 1 1e 1 3a I 1 1:

APPARATUS FOR WET TREATMENT OF PI-IOTOGRAPHIC MATERIALS OR THE LIKE BACKGROUND OF THE INVENTION The present invention relates to apparatus for wet treatment of photographic materiaL. such as webs or sheets of photographic. film. paper or the like. More particularly, the invention relates to improvements in apparatus wherein discrete sheets, webs, strips or the like must be transported through a body of liquid which is heated so that its tempe ature is maintained withina predetermined range.

It is already known to treat photographic material in a vessel or tank wherein the liquid is maintained at a predetermined temperature by a heating unit including one or more elongated heating rods which are connected with a source of electrical energy and are fluidtightly confined in corrosion-resistant metallic pipes.

Such heating units are quite expensive because each rod must be sealingly received'in a discrete pipe, because the pipes must consist of a material which can stand the chemical action of fluids used for the processing of photographic material, and also because each rod must be insulated from the metallic material of the respective pipe.

It is further known to heat water in an aquarium by resorting to heating wires which are embedded into rods or tubes consisting of a vitreous material. Such heating units are much less expensive than the previously described heating units; however, they cannot be used in the processing of photographic material in developing laboratories or like institutions owing to stringent requirements concerning the safety of employees and the prevention of fires.

SUMMARY OF THE INVENTION An object of the invention is to provide a novel and improved apparatus for wet treatment of sheets or webs of photographic material or the like at a predetermined temperature or within a predetermined temperature range.

Another object of the invention is to provide an apparatus which meets all existing requirements regarding the safety of employees and/or prevention of fires but is simpler, less expensive and longer-lasting than heretofore known apparatus.

A further object of the invention is to provide novel and improved means for heating a body of water or another liquid in a vessel for wet treatment of photographic sheet or strip material.

An additional object of the invention is to provide an apparatus wherein one or more parts which are likely or expected to break or to undergo other damage can be rapidly replaced with prefabricated parts at a minimum of cost and without necessitating material alterations of the remaining parts and/or lengthy interruptions in operation.

Still another object of the invention is to provide a novel and improvedheating unit which can be used in apparatus for wet treatment of photographic sheet or web material which can be installed in existing vessels presently using conventional types of heating units.

The invention is embodiedin an apparatus for wet treatment of photographic sheets, webs or the like and comprises a vessel for a body of water or another liquid. The vessel comprises one or more overflow openings or analogous means for maintaining the upper surface of the body of liquid therein below a predetermined level, and the apparatus further includes novel and improved means for heating the body of liquid in the vessel. The heating means comprises at least one insulator (preferably an elongated tube or rod) consisting of glass or other brittle material, at least one filament, wire, rod oran analogous electric resistance heating element which is confined in the insulator, a flexible hose which sealingly surrounds the insulator and the heating element therein and at least one end of which extends above the aforementioned level. and conductor means extending through the one end of the hose and connecting the heating element with a suitable source of electrical energy.

The hose preferably consists of an insulating synthetic plastic material which can withstand the corrosive action of liquid in the vessel as well as the temperature at which the liquid is maintained when the circuit of the electric heating element is completed. In accordance with a presently preferred embodiment of the invention, the hose is shrunk onto and thus closely follows the contour or contours of one or more insulators therein. Such insulator or insulators can be maintained tion, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of an apparatus which embodies the invention;

FIG. 2 is a longitudinal vertical sectional view as seen in the direction of arrows from the line IIII of FIG. 1; and

FIG. 3 is a transverse vertical sectional view as seen in the direction of arrows from the line III-III of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus which is shown in FIGS. 1-3 comprises an elongated trough-shaped vessel or tank 1 which may consist of a corrosion-resistant synthetic plastic material and supports one or more rollers, drums or analogous rotary devices (not shown) for the transport of continuous webs and/or discrete sheets of photographic material through a body of liquid. Such body of liquid can fill the vessel 1 to the level of the lowermost portion of an overflow opening lb provided I in an upright end wall 1a of the vessel 1. The liquid which overflows through the opening 1b enters a compartment or chamber 10 which is adjacent to the end wall 1a. The compartment 10 has an outlet (not shown) through which the liquid can leave to be introduced into a suitable regenerating unit or to be discharged into a drain. It will be noted that the opening lb prevents the upper surface of liquid in the vessel 1 from rising above the level 1d.

The upper edge portions of theend walls 1a, 1e of the vessel 1 are connected to or removably support an I elongated plate-like bridge memberor rail 2 which is located above the level 1d. The bridge member 2 preferably consists of a corrosion-resistant metallic alloy. The underside of the bridge member 2 is connected with the web of a U-shaped distancing member 3 having two

flanges

3a, 3b which extend downwardly into the body of liquid in the vessel 1. The lower edge faces of the

flanges

3a, 3b have recesses or sockets 31' (see FIG. 3) for portions of an elongated flexible hose 4 which is shrunk onto two substantially parallel tubes or rods 1 1, 12 consisting of glass or other vitreous insulating material which is brittle and sealingly surrounds dis- 'crete electric resistance heating elements in the form of aquariums or the like. In accordance with a presently preferred embodiment, each tube has a relatively thin cylindrical wall with a helical metallic filament (11A or 12A) embedded into such wall. The terminals of each filament are connected to conductor means which serve to connect the filaments with a suitable source of electrical energy. The conductor means may extend through one or both end portions 4a, 4b of the flexible hose 4. Each of the conductor means is surrounded by a suitable flexible sheath of insulating material. As a rule, the filaments 11A, 11B are embedded into the tubesll, 12 while the material of the tubes is in a molten state so that, once the vitreous material sets, the filaments are fluid-tightly sealed therein save for the terminals which are connected with the conductor means.

The hose 4 is longer than the tube 1 l or 12; for example, the overall length of the hose may be twice the length of a tube and the tubes are preferably located midway between the end portions 4a, 4b. Those parts (4c, 4d) of the hose 4 which extend beyond the ends of the

tubes

11, 12 are bent upwardly and extend through suitable holes of the bridge member 2. The end portions 4a, 4b are sealed and secured to the upper side of the bridge member 2 by discrete sheet metal clamps 5, 6 best shown in FIG. 1. That portion of the hose 4 which is shrunk onto the

tubes

11, 12 extends into the sockets 3c of the

flanges

3a, 3b so that the member 3 maintains the tubes at a predetermined distance from the level 1d and in the body of liquid which is confined in the vessel 1.

The

reference characters

4, 4" denote those portions of the hose 4 which are shrunk onto the largerdiameter end portions of the

tubes

11, 12; such end portions surround the terminals of the respective heating elements 11A, 12A. It will be noted that the

portions

4, 4" are located at the opposite ends of the two

parallel tubes

11 and 12. The tendency of the hose 4 to straighten automatically insures that the ends of the

tubes

11, 12 extend into the sockets 3c of the

flanges

3a, 3b when the portions 4c, 4d are flexed in a manner shown in FIG. 2, i.e., when the end portions 4a, 4b are clamped to the upper side of the bridge member 2.

Since the end portions 4a, 4b are located well above the levelld and are sealed by the respective clamps 5,

6, the interior of the hose 4 is completely sealed against.

entry of liquid, air, dust or any other foreign matter.

Also, if the 'tub'e"l1 and/or 12 happens to break, its fragments are sealingly confined in the hose 4 so that the filament llA and/or 12A cannot come into contact with the body of liquid in the'vessel l.

The conductor means of the apparatus shown in FIGS. l-3 comprises two insulated

conductors

7, 8 which respectively extend through and beyond the end portions 4b, 4a of the hose 4. These conductors are connected to a temperature regulating device 10 (e.g., a conventional thermostat) which is preferably adjustable to insure that the temperature of liquid in the vessel l is maintained within a predetermined range; The temperature sensing element or elements of the regulating device 10 monitor the temperature of liquid in the vessel 1; such sensing device or devices can be installed in the hose 4 to be held out of direct contact with the body of liquid and they can be connected with the regulating device 10 by one or more wires in the sheath of the

conductor

7 or 8.

It is clear that the improved heating means is susceptible of many further modifications. For example, the hose 4 can be shrunk onto a single glass tube or onto three or more glass tubes. It has been'found that, in most instances, two commerically available glass tubes (with their heating elements connected in series) suffice to insure proper tempering of liquid in the vessel of a photographic developing, fixing, rinsing or like unit. The heat furnished by such pairs of tubes can be readily withstood by a plastic hose.

If desired, the median portion of the hose 4 can surround one or more plate-like spacers (see the plate 9 in FIG. 3) serving to maintain the

tubes

11 and 12 in parallelism with and at an optimum distance from each other. The spacer or spacers 9 preferably consist of a metallic material which is a good conductor of heat so as to insure a uniform distribution of heat to the entire median portion of the hose 4 which latter exchanges heat with the surrounding liquid. 7

It is further within the purview of the invention to" equip the apparatus with means for insuring that the upper surface of the body of liquid in the vessel 1 can not descend below the level 1d. For example, the opening 2a of the bridge member can receive the neck of a liquid-containing bottle which supplies liquid into the vessel whenever the upper surface of the body of liquid in the vessel 1 descends below the level 1d. Such types of liquid supplying means are known in the art of treatment of photographic films or the like as well as in many other arts. They are commonly known as fountains.

An important advantage of the improved apparatus is that its heating means is much less expensive than but just as safe as presently known heating means wherein the electric resistance heating elements are confined in and insulated from corrosion-resistant metallic piping. The hose 4 confines the fragments in the event of breakage of the tube 11 and/or 12 and constitutes a fluid-tight seal around the tubes and heating elements 11A, 12A. Moreover, and since the end portions 4a, 4b of the tube 4 extend well above the level la and are sealed by the clamps 5, 6, the heating elements and their terminals are protected againstcontact with water or another liquid even if such liquid is poured onto the upper side of the bridge member 2, for example, during placing of the neck of a filled bottle onto the opening 2a.

A further important advantage of the improved apparatus is that the entire heating means can be readily replaced within short periods of time. Thus, if the tube 11 and/or 12 breaks, the person in charge simply removes the screws which connect the clamps 5, 6 to the bridge member 2 and disconnects the

conductors

7, 8 from the regulating device 10. The hose 4 is then removed and replaced by a hose containing one or more intact glass tubes. The apparatus can be furnished with one or more spare heating means.

Since the hose is flexible, it not only intercepts the fragments in the event of breakage of the

tube

11 or 12 but also reduces the likelihood of such breakage since it can yield in response to stresses which, in theabsence of the hose, would be transmitted directly to the tubes and would cause breakage.

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 which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended 1. Apparatus for wet treatment of photographic sheets, webs or the like, comprising a vessel for a body of liquid, said vessel having means for maintaining the upper surface of the body of liquid therein below a predetermined level; and means for heating the body of liquid in said vessel, comprising at least one insulator consisting of brittle material, at least one electric resistance heating element confined in said insulator, a flexible hose sealingly surrounding said insulator and said heating element therein, said hose having at least one end portion extending above said level, and electric conductor means extending through said one end portion of said hose and connected to said heating element.

2. Apparatus as defined in claim 1, wherein said insulator is an elongated glass tube and said heating element is a filament which is embedded in said tube.

3. Apparatus as defined in claim 1, wherein said hose consists of insulating synthetic plastic material.

4. Apparatus as defined in claim 1, wherein said hose is shrunk onto said insulator so that it closely follows the contour of said insulator.

5. Apparatus as defined in claim I, wherein said heating means comprises a plurality of insulators and said hose sealingly surrounds said plurality of insulators. each of said insulators confining a discrete heating element.

6. Apparatus as defined in claim 1, wherein said hose has first and second end portions extending above'said level and said conductor means includes first and second conductors extending from the respective end portions of said hose.

7. Apparatus as defined in claim 1, further comprising means for regulating the heating action of said heating element, said regulating means being connected to said conductor means outside of the body of liquid in said vessel.

8. Apparatus as defined in claim 1, further comprising a bridge member supported by said vessel and located above said level, and means for securing said end portion of said hose'to said bridge member.

9. Apparatus as defined in claim 8, wherein said securing means comprises a device for fluid-tightly sealing the end portion of said hose.

- 10. Apparatus as defined in claim 8, further comprising distancing means secured to said bridge member and extending into the body of liquid in said vessel to maintain said insulator at a predetermined distance from said bridge member.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 896 468 DATED y ,1975 |NVENTOR 5 I Liflrgen Muller It is certified that error appars in the above-identified patent and that said Letters Patent are hereby corrected as shown below: 1 A

[73] AGFA-GEVAERT AG, Leverk usen, Federal Republic 7 of Germany Signed and Sealed this 1 I tenth of February 1976 [SEAL] I Arrest:

RUTH c. MASON Commissioner ofParems and Trademark! UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 896 468 DATED 1 y 2,1975

lN\/ ENTOR(S) gen Muller It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

[73] AGFA-GEVAERT AG, Leverkusen, Federal Republic of Germany Signed and Scaled this tenth Day of February 1976 [SEAL] AfteSI.

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner oj'latems and Trademarks

Claims

1. Apparatus for wet treatment of photographic sheets, webs or the like, comprising a vessel for a body of liquid, said vessel having means for maintaining the upper surface of the body of liquid therein below a predetermined level; and means for heating the body of liquid in said vessel, comprising at least one insulator consisting of brittle material, at least one electric resistance heating element confined in said insulator, a flexible hose sealingly surrounding said insulator and said heating element therein, said hose having at least one end portion extending above said level, and electric conductor means extending through said one end portion of said hose and connected to said heating element.

5. Apparatus as defined in claim 1, wherein said heating means comprises a plurality of insulators and said hose sealingly surrounds said plurality of insulators, each of said insulators confining a discrete heating element.

6. Apparatus as defined in claim 1, wherein said hose has first and second end portions extending above said level and said conductor means includes first and second conductors extending from the respective end portions of said hose.

8. Apparatus as defined in claim 1, further comprising a bridge member supported by said vessel and located above said level, and means for securing said end portion of said hose to said bridge member.

10. Apparatus as defined in claim 8, further comprising distancing means secured to said bridge member and extending into the body of liquid in said vessel to maintain said insulator at a predetermined distance from said bridge member.