US2414502A - Drying apparatus for photographic film - Google Patents

Description

Jan. 21, 1947. F. P. WILLCOX 2,414,502

DRYING APPARATUS FOR PHOTOGRAPHIC FILM Filed Sept. 13, 1944 3 Sheets-Sheet 1 I $1 vwento'o Frederick F6021 ZZcox Jan. 21, 1947. w cox 2,414,502

DRYING APPARATUS FOR PHOTOGRAPHIE FILM Filed Sept. 13, 1944 3 Sheets-Sheet 2 7 nvzntoz i Frederic/c BZUL'ZZCOX Jan. 21, 1947. v WILLCQX 2,414,502

DRYING APPARATUS FOR PHOTOGRAPHIC FILM Filed Sept. 15, 1944 -3 Sheets-Sheet 3 uuenfo'o Frederick Z. LUL'ZZCOX a 21 a, a

SHGZHQIJ4 Patented 21, 1947 2,414,502 DRYING APPARATUS FOR PHOTOGRAPHIC Frederick P. Willcox,

Arlingto United States Army, :1, Va.

Application September 13, 1944, Serial No. 553,855

(01. 34-197) (Granted under the act of March 3, 1883, as

8 Claims.

amended April 30, 1928; 370

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without payment to me of any royalty thereon.

This invention relates to a photographic film drying cabinet, particularly a photographic film drying cabinet in combination with an impeller directing a current of air through the cabinet, and more particularly it is directed to a photographic film drying cabinet in combination with an impeller and efllcient heating assembly for directing a current of heated air through the cabinet.

In the past, it has been the practice in the design of equipment of this type to locate an air inlet near the bottom of the cabinet and an exit flue near the top. Various means for heating the air have evolved in the advancement of this art, !or instance combustion gases, heat exchange coils, and electrical elements have been used. The circulation or air through the cabinet has likewise varied, some devices relying on the variance of air densities while others provided impelling and exhausting devices. In all cases, however, the devices were unsatisfactory for many reasons such as contaminating the air, and requiring a large power output to secure an adequate rise in temperature of the air circulated over film supported in the cabinet.

Accordingly, it is an object of this invention to provide a photographic film drying cabinet having an air impeller circulating air therethrough and an efilcient electrical heating assembly for heating the air.

Another object of this invention is to provide a device of the class herein described having the heating element supported by and positioned in air directing vanes forming conduits registering with the air inlet for the impeller.

A further object of this invention is to provide a device of the class herein described which will .be economical and simple to construct and emcient, economical and durable in operation.

The foregoing and other objects of this invention will be more apparent from reading the specification in conjunction with the drawings forming a part thereof, wherein:

Fig. 1 is a perspective view of the impeller, directing vanes, and hood mounted on top of and operably connected with the cabinet;

Fig. 2 is a detailed cross-sectional view showing the construction and arrangement 01 the impeller, directing vanes, and heater element; and,

Fig. 3 is a perspective view showing the structural details the cabinet interior.

In the drawings wherein like members are given the same reference numeral, a plurality of radial spaced impeller blades I are rigidly secured to a rotatably mounted shaft 2 in any suitable manner well known in the art of turbine propellers. The shaft 2 is attached to and rotated by the rotor of an electric motor 3. The impeller blades I are encased in a circular shroud 5, which has a tangential exit conduit 6 perpendicular to the longitudinal axis of the blades I. The air inlet is an annular flanged aperture 4 in axial alignment with the impeller blades.

In order to provide definite channels or conduits through which the air must pass in entering the impeller shroud 5, an outwardly flared, substantially bell-shaped directing vane I is superimposed on and in registering contact with the annular flanged aperture 4 functioning as an air inlet. This directing vane 1 may be securely fastened to the shroud 5 by any suitable means, such as bolting, strapping, welding, and the like. This structure defines one substantially conical conduit leading to the air inlet; however, a more eiilcient structure may be obtained by suspending a smaller, similarly designed vane 8 interiorly the outer vane I and in coaxial alignment therewith. The interior vane 8 may be rigidly suspended from the outer vane 'I by a,

plurality of equally spaced bars or straps I0. These coaxial aligned air directing vanes I and 8 form two distinct channels leading to the air inlet 4, and each of these channels directs air over a heating element I5 positioned in the air paths formed by the directing vanes I and 8. Thus, all of the air entering the system is heated by contact with and radiation from the heating element. The air, however, is also heated by the vanes I and 8 and impeller blades I, which absorb heat radiated from the heating element I5. In order to obtain the maximum heating effect from the vanes I and 8 and blades I, they should be rendered more heat absorptive, preferably by coating with a heat absorptive material such as lusterless black paint.

The supporting bars III, in addition to supporting the inner vane 8, also support, in axial alignment with the impeller blades I and coaxial aligned vanes I and 8, an electrical socket II. The socket II has two electric contacts, one at the base of the socket and the other in association with an internally threaded section II, as is the conventional practice in this art. A molded ceramic form has a hollow conical shaped portion I4 wound with coiled resistance wire Ii to form a heating element, and a cylindrical shaped portion provided with external threads adapted to engage the threaded portion 12 of the socket I I. The heating element wire I is provided with two electrical contacts, one at the base of the ceramic form and the other in association with the external threads it. The electrical circuit is completed upon engagement of the threaded members.

The cabinet, impeller and heater are so connected as to form a single closed conduit, with the air entering the inlet of the directing vanes and leaving through exits provided near the bottom of the cabinet structure. The air directing, heating, and impelling means, above described, are mounted on the top of the cabinet structure insuring a cleaner air supply. A conduit i'i connects the impeller shroud to a pyramidal hood l8 registering with an aperture it! provided in the drying cabinet top member 20. The air in the upper portion of a room is normally clean enough for drying film; however, if fine grain work is to be dried, a filter may be positioned in the hood is or between the hood l8 and registering aperture l9. The cabinet side members 2| are provided with a plurality of apertures 22 near the lower edge thereof to serve as exits for the air directed therethrough by a double arcuate directing vane 26 attached to the bottom member 25. The solid back member 23 and interlocking dual door members 20 complete the cabinet structure forming a part of the conduit.

It is a desirable feature of the cabinet that a portion of the interior thereof be free of shelvin to accommodate roll or strip fllm and the remaining portion have vertically adjustable shelving to accommodate plates of various sizes. Accordingly, there are provided, in the desired length, a plurality of shelves having a width comparable to the depth of the cabinet. Each shelf consists of an angle frame 21 with downwardly extending flanges and a body of heavy wire screen 28 attached to the inwardly extending horizontal flanges of the angle frame 2!. The shelves are supported at three points by upwardly extending flanges 30 engaging the downwardly extending flanges of the angle frame 2'8; and, at another point by a stud 3 attached to the angle frame 21! and inserted in an aperture 53 provided in a vertical supporting member 32. The supporting flanges 30 are stamped in strips 09, in a manner such that they are in spaced relation therewith, and correponding flanges 30 in each strip 3! are in planular alignment. If desired, angle members may be used in lieu of strips 3 i. Two of the flanged strips M are attached to the cabinet back member 23, and another flanged member is secured at the joinder of the side member 2i and interlocking door 24. This latter flange member is preferably stamped in an an le member. These flanged members support the shelves at the back and one front corner. The other front corner of the shelf is supported by stud 84 attached to the angle frame 21 and inserted through an aperture 33 in a vertical support 32. The support consists of an angle member 32 positioned near the front of the cabinet and secured to the top 20 and bottom 25 members .thereof. The elongated apertures 33 are so spaced that they are in planular alignment with the corresponding upwardly extending flanges 30. The stud I4 is secured to the angle frame 21in a position registering with the elongated aperture 03. To insert a shelf, it is tilted upwardly at the back, the stud 84 inserted through an aperture 33 at the desired height, and the front dance of the angle frame 21 placed over the corresponding flange 30. The

members 2 I.

rear portion of the shelf is then pushed downwardly until the angle frame 21 engages the flanges 30 provided on the cabinet back member 23. Thus, the shelves are easily adjusted to the desired height to accommodate articles of various sizes. g

The fabrication and assembly of this device is economical and relatively simple. conventional, rectangular cabinet structure is provided with an aperture I9 in the top member 20 and'a plurality of apertures 22 in the lower section of the side members 2 I. The double arcuate vane 26-iscentrally positioned and fastened tothe cabinet bottom member 25. If it is desired to filter air passing through the cabinet, an air flltermay be positioned over the inlet aperture l9; likewise, a filter cloth may be placed over the exit apertures 22 to prevent the entrance of dust into the cabinet when not in use. The pyramidal hood I8 is constructed of sheet metal and secured in registering contact with the aperture H9 in the cabinet top member 20. The motor 3 and the blower, which is a standard turbine impeller i coated with black paint and encased in a circular shroud 5 having a tangential exit 6 and side inlet 4, are mounted on top of the cabinet and operable connected with the hood 68 by a prefabricated sheet metal conduit H. The directing vanes l and 8 are fabricated from sheet metal coated with lusterless black paint, and assembled with suspending bars l0 having the electric socket Ii secured to them. The ceramic form having the heating element 15 wound thereon is screwed into the socket, and the directing vanes supporting the heater assembly is secured to the flanged air inlet 5 of the blower assembly.

In operation, the device is efficient, economical, and durable. Film plates are supported separately in the cabinet by suspending them from the wire structure 28 of a shelf and they are supported collectively by placing them in a film plate rack resting on the shelf, and roll films are suspended in the unshelved portion of the cabinet. When the doors 2d are shut, a closed conduit for the cabinet is formed with the inlet at the directing vanes l and 8 and outlet at the apertures 22 in the lower section of the side The motor 3 and heating element is are energized thereby pulling air through the channels formed by the directing vanes l and 8 and over the heating element i5. The directing vanes heat the air with absorbed heat radiated from the heating element I5, which also heats the air by radiation and contact. The air is also heated by the radiated heat absorbed by the impeller blades I which propels it through the conduit ll, hood i8, and cabinet where it is directed -by the double arcuate vane 25 out the apertures 22.

As an example of the increased efflciency ,obtained in the device described herein, a four inch impeller driven by a /5 H. P. motor produced an output of approximately 250 cubic feet of air a minute atan increased temperature of 35 F. in the cabinet above atmospheric temperature with a heater element current consumption of only 660 watts; whereas, a similar structure without directing vanes I and 8 and having the heating element disposed across the impeller exit 6 consumed in excess of 2000 watts to produce the same temperature rise.

Having thus described my invention, what I claim as new and wish to secure by Letters Patentis:

1. In combination. a cabinet having adjustable A standard,

impeller having an air conduit; and, an electrical heating device comin the cabinet top member, a conduit operably connected with said hood, and an encased air impeller having an air exit registering with said conduit; and, an electrical heating device comprising air directing vanes, secured to the inlet of said encased impeller, and an electrical heating element supported by said directing vanes, said combination being constructed and arranged in a manner such thatsaid impeller draws heated air from said heating device and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air directing vane.

a hood registering with and inserted over said aperture in the cabinet top member,-a conduit operably connected with said hood, and an encased air impeller having anair exit registering with said conduit; and, an electrical heating device comprising air directing vanes attached to the inlet of said impeller, and an electrical heating element supported interiorly said air directing vane, said combination being constructed and arranged in a manner such that said impeller draws heated air from said heating device and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air directing vane.

3. In combination, a cabinet having adjustable shelves occupying a vertical portion thereof, an aperture in the top of said cabinet, a plurality of apertures in the lower portion of the side members of said cabinet, and a double arcuate air directing vane located interiorly said cabinet and attached to the bottom member thereof; a hood registering with and inserted over said aperture in the cabinet top member, a conduit operably connected with said hood, and an encased air impeller having an air exit registering with said conduit; and, an electrical heating device comprising a plurality of air directing vanes coaxially aligned with said impeller, and a heating element positioned in axial alignment with said air directing vanes, said combination being constructed and arranged in a manner such that said impeller draws heated air from said heating device and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air directing vane.

4. In combination, a. cabinet having adjustable shelves occupying a vertical portion thereof, an aperture in the top of said cabinet, a plurality of apertures in the lower portion of the side members of said cabinet, and a double arcuate air directing vane located interiorly said cabinet and attached to the bottom member thereof; a. hood registering with and inserted over said aperture in the cabinet top member, a conduit operably connected with said hood, and an encased air prising coaxially aligned substantially-bell-shaped air directing vanes attached to the air inlet or said impeller, and an electrical heating element posithrough said cabinet over and against said double arcuate air directing vane.

5. In combination, a cabinet having adjustable shelves occupying a vertical portion thereof, an aperture in the top 01' said cabinet,-a plurality of apertures in the lower portion of the side members of said cabinet, and a double arcuate air directing vane located interiorly said cabinet and attached to the bottom member thereof; a hood registering with and inserted over said aperture in the cabinet top member, a conduit operably connected with said hood, and an encased air impeller having an air exit registering with said conduit; and, an electrical heating device comprising air directingvanes attached to the inlet of said impeller, a heat absorptive coating on said directing vanes, and an electrical heating element supported by said directing vanes, said combination being constructed and arranged in a manner such that said impeller draws heated air from said heating device and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air directing vane.

6. In combination, a cabinet having adjustable shelves occupying a vertical portion thereof. an aperture in the top of said cabinet, a plurality of apertures in the lower portion of the side members of said cabinet, and a double arcuate air directing vane located interiorly said cabinet and attached to the bottom member thereof; a hood registering with and inserted over said aperture in the cabinet top member, a conduit operably connected with said hood, and an encased air impeller having an air exit registering with said conduit; and, an electrical heating device comprising air directing vanes attached to the inlet of said impeller, a heat absorptive coating on said directing vanes, and a heating element supported interiorly said directing vanes, said combination being constructed and arranged in a manner such that said impeller draws heated air from said heating device and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air directing vane.

7. In combination, a. cabinet having adjustable shelves occupying a vertical portion thereof, an aperture in the top of said cabinet, a plurality of apertures in the lower portion of the side members of said cabinet, and a double arcuate air directing vane located interiorly said cabinet and attached to the bottom thereof; a hood registering with and inserted over said aperture in the cabinet top member, a conduit operably connected with said hood, and an encased air impeller having an air exit registering with said conduit; and, an electrical heating device comprising a plurality of air directing vanes coaxially aligned with said impeller, a heat absorptive coating on said directing vanes, and an electrical heating element positioned in coaxial alignment with said directing vanes, said combination being constructed and arranged in a manner such that said impeller exit registering with said draws heated air from said heating device' and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air directing vane.

8. In combination, a cabinet having adjustable shelves occupying a vertical portion thereof, an aperture in the top or saidcabinet, a plurality of apertures in the lower portion of the side members of said cabinet, and a double arcuate air directing vane located interiorly said cabinet and attached to thebottom member thereof a hood registering with and inserted over said aperture in the cabinet top member, a conduit operably connected with said hood, and an encased air directing vane.

impeller having an air exit registering with said conduit: and. an electrical heating device comprising coaxially aligned substantially bell-shaped air directing vanes attached to the inlet of said air impeller, a heat absorptive coating on said directing vanes, and an electrical heating element positioned in coaxial alignment with said directing. vanes, said combination being constructed and arranged in a manner such that said impeller draws heated air from said heating device and directs said heated air through said top cabinet aperture thence downwardly through said cabinet over and against said double arcuate air FREDERICK P. WILLCOX.

Images