US3811767A

US3811767A - Portable collapsible darkroom

Info

Publication number: US3811767A
Application number: US00369161A
Authority: US
Inventors: H Purnell
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-06-12
Filing date: 1973-06-12
Publication date: 1974-05-21
Anticipated expiration: 1991-05-21

Abstract

A portable, collapsible darkroom comprising a housing formed of two hingedly attached sections opening up to overlie one another on the same plane, with a framework disposed within the housing and extensible therefrom to form, with the housing, a substantially rectangular enclosure, and a light-proof canopy enclosing the framework and housing interior. The housing interior supports a photographic enlarger and baseboard secured to, and vertically adjustable in respect of, a pair of aligned posts, and a series of developing trays removeably supported on the housing interior. Air circulation is provided by a blower and baffled vents, and light by a fixture, both secured to the housing interior and wired, with the enlarger, to a source of electricity outside the darkroom.

Description

[22] Filed:

United? States Patent [191 Purnell PORTABLE COLLAPSIBLE DARKROOM [76]- lnventor: Herbert L. Purnell, 1700 York Ave., New York, NY. 10028 June 12, 1973 [2]] Appl. No.: 369,161

[52 us. c .f5 /g], 3 54/ 31Q 7 [51 lnLCl. ..G03b 27/32 [58] FieldofSearch.... 95/90,91,92;355/ 27' [56] References Cited UNITED STATES PATENTS Primary Examiner-John M. Horan Attorney, Agent, or Firm-Sydne,y B. Schlessel Erikson 95/91 1 [57] ABSTRACT A portable, collapsible darkroom comprising a hous- V ing formed of two hingedly attached sections opening 'up to overlie one another on the same plane, with a framework disposed within the housing and extensible therefrom to form, with the housing, a substantially rectangular enclosure, and a light-proof canopy enclosing the framework and housing interior. The housing interior supports a photographic enlarger and baseboard secured to, and vertically adjustable in respect of, a pair of aligned posts, and a series of developing trays removeably supported on the housing in terior. Air circulation is provided by a blower and-baffled vents, and light by a fixture, both secured to the housing interior and wired, with the enlarger, to a source of electricity outside the darkroom.

7 Claims, 7 Drawing Figures PATENTED H AY 2 1 I974 SHEET 1 [If .3

PATENTED MAY 2 1 I974 SHEEI20F3 PATENTEnmzl mm SHEET 30F 3 Him 'i' PORTABLE COLLAPSIBLE DARKROOM BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to the field of photographic development and enlargement, and more particularly to the creation of a portable darkroom for the development of photographic film and the making of prints and enlargements therefrom, which can be collapsed to occupy a small area of vspace and conveniently stored when not required for use, and which can be set up in any selected area.

2. Prior Art Photographic film, after initial exposure in a camera, must be developed in a developing mediumunder conditions which must exclude all light, both in the removal of the film from its container and during the process of development, since any secondary or subsequent exposure of the undeveloped film will either destroy and spoil the effectsof the initial exposure intaking the pictures. Similarly after the film has been de-' veloped and fixed as a negative, and prints are desired,

either contact or enlarged,the exposure of the negative to a light-sensitive paper mustbe done in an area where direct light of any kind, other than light from what is known as a safelight is completely excluded, except such light as is'directed on to the light-sensitive paper through the film negative in the process of exposure. The thus exposed paperis then developed in a paper developingmedium under the same conditions. Following development, washing and fixing of the print, it may then be exposed to light without harm.

In the present state of the art the foregoing is generally accomplished in what is termed a darkroom, that is to say, a fixed, enclosed area, generally a room without windows, from which all outside light canbe effectively excludedduring the procedures described above. Naturally, with the necessity for the required equipment, chemicals, developing and washing trays, paper, etc., a considerable amount of space is required, which has otherwise no function, andit is clearly impractical, for example, for non-professional photographers (whosenumber has increased greatly in the past few years) to set aside such space for this purpose alone. Even professional photographers, whose work frequently takes them far from their establishments, find themselves hampered by having to delay development of their efforts until they return to their regular dark-' nient or satisfactory. For example there have been de veloped portable structures where the photographer must stand outside the structure while his hands are disposed within thestructure (see U.S. Pat. Nos, 684,803; 779,748; 2,484,048).

v BRIEF SUMMARY OF THE INVENTION The disadvantages of the aforementioned structures are clearly overcome by my invention, which provides a portable, collapsible housing to'enclose' both the pholight in weight and which, when collapsed, can be moved easily and stored in a small area, such as a closet or the, like, when not in use, arid which, when opened and with its interior elements extended, as will be hereinafter described, forms a substantially large and completely light-proof enclosure adapted to contain and support all necessary equipment for film development and printing, as well as provide adequate room within and provides adequate room therein for the operator to be conveniently accommodated.

A second important object of my invention lies in the provision of a darkroom as above described wherein the required equipment forms a part of the internal structure of the housing.

A third important object of my invention lies in the provision of a darkroom as above described wherein the required equipment can be disassembled and stored provision of a darkroom as above described wherein tographer and all of his necessary equipment, which is provision is made for complete air circulation therethrough without light exposure of the interior.

Still another important object of my invention lies in the provision of a collapsible darkroom as above described, which is inexpensive to manufacture and which can be quickly and easily assembled and disassembled. I

' These and other salient objects, advantages and func tional features of my invention, together with the novel features of construction, compositionand arrangement of parts, will become more readily apparent from an examination of the following specification, taken with the accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side perspective view of a preferred embodiment of my invention in assembled position, partly broken away to show internal construction of the can- FIG. 2 is a view similar to FIG. 1, but with the canopy removed;

FIG. 3 is a side view my invention, partly broken away;

FIG. 4 is a front view on lines 44,of FIG. 3;

FIG. 5 is a front view of the housing of my invention in disassembled, closed position, showing disposition of the interior elements;

FIG. 6 is an end view of the embodiment of FIG. 5; and

FIG. 7 is an enlarged top view, partly in section,

showing the manner of extension of the framework disposed within the housing of my invention.

Similar reference characters designate similar parts throughout the different views.

of the interior of the housing of- DETAILED DESCRIPTION OF THE INVENTION Illustrative of the embodiment shown by the drawings, my portable,.collapsible darkroom comprises a housing 10 formed by two substantially rectangular, identically sized

sections

12 and 14, section 12 formed with a base 16, with a wall 18 extending at right angles therefrom, and section 14 formed with a base 20, and a wall 22 extending at right angles therefrom,

sections

12 and 14 being secured together along shorter sides of

walls

18 and 22, as by piano hinge 24, as shown in FIG. 4, and provided with a locking means (not shown) upon their opposing shorter sides, whereby the

sections

12 and 14 may be secured together as a housing 10 to define a central chamber thereinbetween. A pair of casters 26 are provided on adjacent longer sides of the

walls

18 and 22, while a handle 28 is provided on the opposing longer sides of

walls

18 and 22, as shown in FIG. 5, so that the housing 10, when closed and locked, can be laid on its side carrying the casters 26, to facilitate easy removal of the housing from place to place, and storage in a convenient closet or the like. The housing 10 is composed, preferably, of a light wood, or metal such as aluminum, but other materials, such as synthetic resins and plastics, may be used as well.

In the preferred form of the invention the housing 10, when closed, will measure 30 inch x 42 inch, with a depth of 10 inch, so that, when

sections

12 and 14 are opened and supported one on top. of the other, as seen in FIGS. 2 and 4, the overall measurement of the open 8 housing 10 will be 30 inch in width, 84 inch, or 7 feet,

in height, with a chamber depth of inch, approximately, allowance being made for the thickness of the material forming the housing 10. These measurements, however, are by no means critical, merely preferable, and the over-all size of the housing may be modified within the scope of functional application.

Referring now to FIGS. 3 and 4, the interior of section 12 is provided with a post 34 set at one side thereof, supported in sockets 36, post 34 being removeable by reason of a tension spring (not shown) secured within one of the sockets 36, as iswell known in the art. A photographic enlarger 38 is mounted on the post 34 and secured thereon for rotative and vertical movement by means of a set screw (not shown), whereby the enlarger 38 can be raised or lowered upon the post 34, and can be' rotated to fit within the interior of section 12. A similar post 40 is provided within section 14 and supported in sockets 42 in manner similar to support of post 34, both posts being aligned, as shown in FIG. 4, with post .40 supporting a compartmented baseboard 44, moveable vertically along post 40 and secureable at any selected height thereon, by operation of a set screw (not shown). Baseboard 44 is provided with a frontal opening 46 in its compartmented portion, through which light-sensitive paper, enclosed in an opaque protective sleeve, may be inserted, for use as will hereinafter be described, and baseboard 44 can be removed from post 40 for storage within the housing, when not in use, by releasing post 40 from its sockets 42, removing the baseboard 44 therefrom, thereafter replacing post 40. i

On the innersurface of bases 16 and there are provided a series of parallel, vertically disposed slotted members 48 adapted to rigidly support a series of developing trays 50 in spaced relationship, as shown in FIGS. 2, 3 and 4, by means of removeable support members 52, fitting beneath the downwardly curved lips of the trays 50, engaged within slots of members 48. To the inner surface of wall 18 of section 12 there is secured a light fixture 54 for retention of a safelight, and an exhaust blower 56 opening into a port 57, the blower 56, fixture 54 and enlarger 38 being wired in same circuit engagement by means of an electric cord (not shown) adapted to extend from the interior of the housing 10 to be inserted into the wall outlet of an electric source, or connected to a battery where the formed is not available, the light fixture 54, blower 56 and enlarger provided locally with separate contact switches (not shown), whereby each can be activated separately, if desired. The lower portion of base 20 of housing section 14 is provided with a series of air vents 58, covered by baffles 60, whereby air may be drawn through the housing 10 in the operation of the blower 56, while excluding entry of light through the vents 58.

Coming now to the extensible structure of my inven tion, and referring particularly to FIGS. 2 and 7, section 12 is provided with a pair. of arms 62, preferably of tubular aluminum, which are slideably and pivotally mounted, at one end, within a sleeve 64 secured to the inner surface of base 16 of section 12, near the top thereof, as shown, and at the other ends similarly disposed within a secondary sleeve 66, the arms 64 being so angled near their engagement with the sleeve 64 so as to permit movement of the arms 62 outwardly from the sleeve 64 to their abutment against the wall 18, as shown in FIG. 7 in solid lines, for enlargement of the area encompassed by the arms 62, and to permit movement of the arms 62 inwardly within the sleeve 64 to the abutment of the arms 62 against the edges of the sleeve 64, as shown by the broken lines of FIG. 7, the arms 62 moving reciprocally with respect to the sleeve 66 so as to maintain the arms 62 parallel to each other at all times. Rotating of the arms 62 out of the housing 10 is facilitated and controlled by a pair of guide members 68, with each secured at one end to a sleeve 70 mounted on an arm 62, and with its other end disposed within a channel 72 in the base 16, the length of the channels 72 being such as to limit pivotal movement of the arms 62 to. a position at right angles to the base 16, as shown in FIG. 2

Each of the arms 62 is provided with a support rod 74 pivotally secured thereto by links 76, and rotatable with respect to the arm 62 from a position parallel thereto to a position at right angles thereto as seen in FIG. 2, with the free ends of the rods 76 threaded, and each with a coupling 78 mounted thereon, for the purposes to be hereinafter disclosed.

The interior of housing section 14 is provided with an identical pair of parallel arms 80 disposed within

sleeves

82 and 84 identical to

sleeves

64 and 66 heretofore described, sleeve 82 being secured to and near the bottom of the base 20, the arms 80 being moveable and pivotal in'the same manner, and controlled in the same manner by guide members 68 secured to sleeves 70 and within channels 72. Each of the arms 80 is similarly provided with a support rod 88 pivotally secured thereto by links 76 and rotatable from a position parallel to its arm 80 to a position at right angles thereto, with the end of each rod 88 threaded in the same manner as rods 74. With the extension of

arms

62 and 80 at right angles to the

housing bases

16 and 20, and with the disposition of their respective support rods 74 and the ends of

rods

74 and 88 will contact in alignment,

' whereby the couplings 78 on rods 74 can be threaded to rods 88 to lock the

respective rods

74 and 88 together, thereby creating a rigid, substantially rectangular framework connected to and extending out of the housing 10, as shown by FIG. 2. It is here to be noted that the arms 80 are curved, as shown in FIGS. 2 and 3, so that the main portions of the arms'80 rest on the same plane as the outer surface of wall 22, thereby providing horizontal stability and rigidity to the assembled darkroom.

Referring now to FIG. 1, there is provided, in combination with the aforementioned structures, a canopy 90 adapted to completely enclose the interior'of the housing and the extending framework, the canopy 90 composed of a sturdy lightweight and light-proof material soft enough to be folded, when not in use, to be disposed within the interior of the closed housing 10. Canopy 90 is formed to fit snugly around the previously described framework of

arms

62 and 80, and co-acting

rods

74 and 88, and adapted to have its free edge fit into the housing 10, the free edge of the canopy 90 being provided with a plurality of suitable snap members (not shown) adapted to come into registry with and be engaged by complementary snap retainers (not shown) mounted along the

inner surfacesof walls

18 and 22,, so that the canopy 90 is sufficiently embraced within the housing 10 to exclude all ambient light. Canopy 90 comprises a top wall 92, bottomwall 94, side walls 96 and front wall 98, the latter provided with a central opening I00, for entrance into the interior therethrough. Canopy9il is further provided with an exterior flap 102 and an interior flap. 104 covering front wall 98 and opening 100, secured to the canopy 90 along the top edge of front wall 98, so that one of the

flaps

102 and 104 covers the opening 100 at all times of egress from and ingress into the enclosure provided.

OPERATION OF THE INVENTION In the collapsed and stored state of my portable darkroom the

sections

12 and 14 are locked together, with the interior chamber thereof containing all of the equipment heretofore described, that is to say, the enlarger 38 has been pivotted to the position shown by the broken lines in FIG. 4, the trays 50 have been disassembled and nested in one another, with support members 52, baseboard 44 has been removed from post 40 and disposed within the chamber, and canopy 90 has been folded and overlaid upon the aforementioned equipment.

When the darkroom is required for use for, let us say, enlargements prints of negatives, the housing 10 is wheeled'to the desired area and opened, and the stored spread apart as heretofore indicated, and the support rods 74 dropping vertically. Support rods 88 are indi vidually raised to meet the ends of respective support rods 74, and couplings 78 are tightly threaded to the rods 88, whereby a rigid support framework is created to support the housing 10 in a stable vertical position. Post 40 is removed for installation thereon of baseboard 44, and replaced. Enlarger 38 is pivoted to overlie the baseboard'44.Canopy 90 isthen slipped around the framework and secured to the interior of

walls

18 and 22 of the housing '10. Tray supports 52 are mounted in the slotted members 48. Trays 50 are filled,

respectively, with developer solution, water and fixitive solution, and mounted on the supports 52. The exhaust blower 56, safelight 54 and enlarger 38 are then connected to an appropriate source of electric power, and the darkroom is ready for operation. Disassembly and storage of the darkroom is accomplished by reversing the above steps. p

The foregoing disclosure describes only a preferred embodiment of my invention. It is apparent that various changes may be made within its scope. For example, posts 34 and 40 may be modified to accommodate different types of photographic enlargers, the canopy 90 may be modified in its attachment to the housing 10, the framework may be modified, both as to material composition and extension elements, the framework may be automated, and suitable cubicles provided within the housing 10'for storage of chemicals, tongs, etc.

From the foregoing, therefore, it is obvious that the embodiment shown and described is by way of illustration and not of limitation, and that various changes may sections of identical size and shape comprising each a base and a surrounding wall extending at right angles from the base, the sections disposed, when secured together in closed position, to define an internal chamber for the housing, a hinge pivotally securing the sections together along abutting wall edges, the sections adapted, when fully opened, to stand one atop the other in the same plane to form the housing,- a framework secured to and recessed within each of the sections in collapsed state and extensible therefrom to form, with the opened sections of the housing, and define therewith, a :rigid room-sized-enclosure, anda light-proof canopy removeably secured around the framework and the housing interior to define a darkroom.

2. A portable, collapsible darkroom as described in claim 1, a post secured in each of the sections, a photographic enlarger slideably and rotatively mounted on one of the posts, with means to activate the enlarger extending from the housing, a baseboard slideably mounted on the second post and in alignment with the enlarger, a plurality of developing trays and means within the housing to support the trays in spaced relav 4. A portable, collapsible darkroom as described in claim 3, baffles provided over the air vents to exclude light from entering through the air vents.

5. A portable, collapsible darkroom as described in claim 4, a safelight provided in the housing wall, with means to activate the safelight extending from the housing.

6. A portable, collapsible darkroom as described in dividual activating switches for each.

Claims

1. A portable collapsible darkroom comprising a housing formed of a pair of substantially rectangular sections of identical size and shape comprising each a base and a surrounding wall extending at right angles from the base, the sections disposed, when secured together in closed position, to define an internal chamber for the housing, a hinge pivotally securing the sections together along abutting wall edges, the sections adapted, when fully opened, To stand one atop the other in the same plane to form the housing, a framework secured to and recessed within each of the sections in collapsed state and extensible therefrom to form, with the opened sections of the housing, and define therewith, a rigid room-sized enclosure, and a light-proof canopy removeably secured around the framework and the housing interior to define a darkroom.

2. A portable, collapsible darkroom as described in claim 1, a post secured in each of the sections, a photographic enlarger slideably and rotatively mounted on one of the posts, with means to activate the enlarger extending from the housing, a baseboard slideably mounted on the second post and in alignment with the enlarger, a plurality of developing trays and means within the housing to support the trays in spaced relationship to each other.

3. A portable, collapsible darkroom as described in claim 2, an exhaust blower secured in one end of the housing and air vents provided at the other end of the housing, a port in the housing wall in registry with the blower, and means to activate the blower extending from the housing.

4. A portable, collapsible darkroom as described in claim 3, baffles provided over the air vents to exclude light from entering through the air vents.

6. A portable, collapsible darkroom as described in claim 5, casters provided on the outer surfaces of adjoining walls of the housing, and a handle secured to the outer surfaces of opposing walls of the housing.

7. A portable, collapsible darkroom, as described in claim 5, the means to activate the enlarger, exhaust blower and safelight being on the same circuit, with individual activating switches for each.