US2546598A

US2546598A - Daylight developing tank for roll film

Info

Publication number: US2546598A
Application number: US101166A
Authority: US
Inventors: Leonard H Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-06-24
Filing date: 1949-06-24
Publication date: 1951-03-27
Anticipated expiration: 1968-03-27

Description

Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE DAYLIGHT DEVELOPING TANK FOR ROLL FILM 1 Claim.

This invention relates to photographic equipment, and more particularly to a tank for use in developing film.

The object of the invention is to provide a tank which will facilitate the development of roll film, the tank being constructed so that the film can be developed during daylight.

Another object of the invention is to provide a film developing tank which is adapted to receive the film after it has been unwound from the spool, the film extending longitudinally through the tank whereby the entire film is developed simultaneously by the fluid or solution in the tank.

Still another object of the invention is to provide a developing tank which includes film supporting posts whose position can be adjusted in the tank whereby films of various sizes and lengths are being developed.

A further object of the invention is to provide a film developing tank which is extremely simple and inexpensive to manufacture.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure l is a front elevational View of the film developing tank, according to the present invention;

Figure 2 is a top plan view of the tank;

Figure 3 is a sectional view taken on the line 3-3 of Figure 5;

Figure 4 is a sectional view taken on the line 4-4 of Figure 5;

Figure 5 is an enlarged sectional view taken on the line 55 of Figure 6;

Figure 6 is a sectional view taken on the line B-6 of Figure 5;

Figure 7 is a view showing certain constructional details of the tank; and

Figure 8 is a sectional view taken on the line 8-8 of Figure 5.

Referring in detail to the drawings, there is shown a tank for developing film and the tank includes a bottom wall [0, and projecting from the bottom wall and secured thereto is a pair of spaced sidewalls H and I2. The sidewalls II and I2 of the tank are of arcuate formation and have their convex faces facing inwardly as best seen in Figure so that a minimum quantity of developing solution will be required to fill the tank in order to develop the film strip. The tank further includes spaced parallel end walls l3 and I4 which are arranged between the sidewalls Ii and I2 and are secured thereto.

A cover or lid 15 is mounted for movement into and out of closing relation with respect to the top of the tank, there being a plurality of hinges I6 for hingedly connecting the cover IE to the upper end of the sidewall [2. A sealing means i provided for insuring that no light enters between the cover l5 and the walls of the tank and further, this sealing means serves to prevent any accidental loss of fluid from the tank when the tank is being agitated. This sealing means comprises a rectangular body member I"! which extends around the inner surfaces of the sidewalls and end walls and is secured thereto. The body member IT is arranged adjacent the top of the tank and coacting with the body member I"! is a second body member l8 which is rectangular in shape also. The body member [8 is secured to the inner or lower surface of the cover l5 and is of such a size so as to snugly seat between the sidewalls and endwalls of the tank when the cover is in closed position on the tank, to thereby provide a fluid tight seal between the cover and tank.

The cover [5 carries an inlet means whereby the tank can be filled with suitable fluid and this inlet means has a trap 4 associated therewith so that light will be prevented from entering the tank. This inlet means comprises a support member [9 which is provided with an oval shaped opening or port 20 for the ingress therethrough of suitable fluid. The support member IS includes a pair of spaced parallel legs 2| and 22 which have secured to their lower ends a fiat plate member 23, Figure 5.

Suitable blocks

24 and 24, Figure 7, extend between the lower or inner surface of the cover [5 and the upper surface of the plate member 23 and are secured thereto. Arranged adjacent one end of the plate member 23 and extending between the cover l5 and plate member 23 is a pair of L-shaped members 25, there being a similar pair of members 26 extending between the other end of the plate member 23 and the cover 15. Thus, fluid entering the tank passes through the opening 20, and then passes through the space between the legs 2i and 22 and out through the space between the

spacer blocks

25 or 26 or out through openings 6 in the plate member 23. Thus, the fluid will follow a tortuous path through the trap so that light will be prevented from entering the interior of the tank.

Arranged in the tank and supported on the bottom wall In is a pair of blocks 21 and 28,

3 Figure 6. The blocks 21 and 28 are each tapered or sloped downwardly towards the center of the tank so that a well is formed centrally in the tank.

Each of the blocks 21 and 28 is provided with a plurality of openings 29, the openings being arranged in pairs, for receiving therein the lower ends of dowel posts or pins 30. Each of the dowel posts 30 includes a lower vertical section 3| which is arranged in engagement with the proper opening 29, and the dowel post further includes an upper inclined section 32. In use, each of the dowel posts 30 are arranged so that a pair of the dowel posts project from each of the blocks 21 and 28 and the dowel posts provide a space therebetween. Then, the film strip 33, which is to be developed, is inserted in the space between the dowel posts 30. Since the upper section 32 of the dowel post 30 diverges or is inclined outwardly, the insertion of the film strip 33 in the space between the coacting dowel posts will be facilitated. A tapered clip 34 is arranged in engagement with each of the free ends of the film strip 33 and the clips 34 abuts the corresponding dowel posts to maintain the film strip 33 stretched longitudinally in the tank.

Further, an outlet means is provided for the discharge or egress therethrough of the fluid from the tank and the outlet means is provided with a trap to prevent light from entering the tank. This outlet means is designated generally by the numeral 8 and the outlet means comprises a support member 35 which is provided with an oval shaped opening or vent 36 for the discharge therethrough of fluid, the opening 36 registering with an opening 31, Figure 5, in the sidewall H. The trap 5 includes an arcuate plate member 38 which is spaced from the inner surface of the sidewall II and a pair of

blocks

39 and 40 extend between the sidewall H and plate member 38 and are secured thereto. Further, a light stop 4| is arranged transversely with respect to the

members

33 and 40 and the member 41 coacts with a pair of members 42 and 43 to define a tortuous path for the fluid leaving the tank. Thus, the trap 4 and 5 insures that no light will accidentally enter the interior of the tank [0.

Further, the developing tank is provided with a latch 44, Figure 1, and the latch 44 serves to maintain the cover in its closed position as desired, in order to prevent accidental opening of the cover l5.

From the foregoing, it is apparent that a tank has been provided which is especially suitable for use in developing roll film. The tank can be used for developing such film during the daylight, since the tank is constructed so as to prevent any light from accidentally entering the tank and destroying the film being developed therein. Thus, in use, the film strip 33 is unwound from its spool and the film strip 33 is extended longitudinally in the tank. One end of the film strip 33 is interposed between one pair of the dowel pins 30, while the other end of the film strip 33 is positioned between the other pair of dowel posts 30. Then, the clip 34 is arranged in engagement with each end of the film strip 33 in order to maintain the film strip stretched longitudinally in the tank. Suitable fluid can be placed in the tank through the inlet opening 20. Further, when fluid is to be retained in the tank, a suitable plug may be used to close the opening 36, and when the fiuid is to be discharged from the tank, the plug can be removed from the opening 36 to permit the discharge therethrough of the fluid. Also, film strips 33 of various lengths can be supported in the tank. Thus, the dowel posts 30 can be positioned in the proper openings 29 whereupon the distance between the complementary pairs of dowel posts can be varied as desired. Also, the openings 30 and 36 need not necessarily have an oval shape, and in lieu of using a plug to close the openings 36, a conventional outlet faucet may be substituted. The opening 20 can also receive the discharge end of a funnel to facilitate the filling of the tank.

What I claim:

A device for developing film, comprising a bottom wall, end walls projecting from said bottom wall and secured thereto, a pair of spaced side walls projecting from said bottom wall and secured thereto, said side walls being of arcuate formation with their convex faces facing inwardly, a cover hingedly connected to one of said side walls, a first body member secured to the inner surface of said end and side walls and arranged adjacent the upper ends thereof, a second body member secured to the inner surface of said cover and coacting with said first body member to provide a fiuidtight seal when the cover is closed on said tank, inlet means on said cover for filling said tank with fluid, outlet means for discharging fiuid from said tank, a latch for preventing accidental opening of said cover, a pair of blocks secured to the inner surface of said bottom wall, said blocks being tapered to define a well intermediate the ends of said tank, a pair of spaced coacting posts adjustably supported by each of said blocks for supporting a roll of film in said tank, said dowel posts having a lower vertical section and an upper inclined section to facilitate the insertion of the film between said posts.

LEONARD H. HARRISON.

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

UNITED STATES PATENTS Number Name Date 907,942 Zierath Dec. 29, 1908 951,983 Center Mar. 15, 1910 1,130,152 Davis Mar. 2, 1915 FOREIGN PATENTS Number Country Date 567,200 Great Britain Feb. 1, 1945