US400140A

US400140A - Lantern or lamp

Info

Publication number: US400140A
Authority: US
Publication date: 1889-03-26
Anticipated expiration: 1906-03-26

Description

{No.Model.)

G. W. STOCKLY LANTERN 0R LAMP.

N. Punks, MLMnpw. www", D. c.

UNTTED STATES PATENT GEEICE.

GEORGE lV. STOCKLY, OF CLEVELAND, OlllO.

LANTERN OR LAMP.

SPECIFICATION forming part of Letters Patent lf3. 400,140, dated March 26, 1889.

Application tiled September 18, 1888. Serial No, 285,666. (No model.)

To all 107mm/ z'f may concern:

.Be it known that l, GEORGE W. S'rocKLY, ot Cleveland, in the county of Cuyahoga and State oi' Ohio, have invented certain new and useful Improvements in Lanterns or Lamps; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention rela-tes to la-nterns or lamps vfor photographic dark-rooms, to be used in furnishing a proper amount ot light for the various stages in the operation of developing` negatives. The utility of such a lantern or lamp, capable of instantaneous manual adjustment to give any desired variation in the quantity oi illumination furnished by it, will be apparent to all who have worked in photographic dark-rooms.

In the use of modern dry-plates, especially those that are exceedingly sensitive and rapid in action, a very small amount of light is all that can be safely used in the dark room while taking such plates out ot their wrappings and placing them in the plate-holders previous to an exposure in the camera. Similar care and an equally small light are necessary in taking the plates out of the holders after an exposure and while placing them in the developing-pans ready for the application et the developers. No more light should be used up to this point than is absolutely necessary to enable the opera-tor to do the work. As soon, however, as the developer has been applied to the dry-plate and the process of development has fairly commenced, a little more light can safely be used, and as the process ot.' development advances more and more light can safelybe used without. injury to the plates. This increased amount of light is necessary to enable the operator to determine the proper moment. After the development ls completed and the fixing process which tolinto the dark-room.

lt will be obvious from this brief statement i that a dark-room lantern or lamp which can be instantly adjusted to give a light varyingI to a comparatively bright but non-actinic light must be of value; and it is the object of my present invention to accomplish this important result; and to this end it consists, generallyspeaking, in a screen ot' non-actinic material, so arranged that various degrees ot,

quantities of light may be transmitted through its several parts, these ehangesin the position of the screen being made by manual means.

In the accompanying drawings, Figure l is a view in side elevation ot' my device, portions of its interior being indicated in dotted lilies. Fig. 2 isa top plan view. Fig. is a sectional view on line fr x, Fig. l. Fig. at is amodification; and Fig. is a view in section on line Y Y, Fig. l.

Obviously, there are many ways ot.' embodying my invention in practical torm, and the following constitutes the most feasible.

A represents a practically light-tight box, square or round, as desired, of either wood or metal, and provided with openings o., such openin gs being' placed so that light from the inside will be projected in any desired direction. l have teun d it convenient in constructing lanterns ot this character to have two openings at right angles to each other, making it possible to throw a light on the developing apparatus in lfront ot' the lantern, and also on one side of it. The main feature ot my invention consists, however, in a screen, B, of non-actinic colored paper, or any other material which admits the passage ot' light.

vThis screen is preferably of cylindrical form,

s0 arrangedv that it will revolve close to the inner wall of the outer casing, A, a crank or handle, c, being furnished this screen and projecting through the box A,whereby motion may be applied. This non-actinic screen is made in such a way that at one point in its circumference, or on one side of it, as at E, Fig.

1 3, there is onlyone thickness ot paper or other the progress ot the development of the latent t nuage and to check. this development at just material, or not unich obstruction to the penetration of light, and therefore at this point a comparatively large amount ol light will be 3 transn'iitted through the screen trom the canlows 1s runder way, still more light may be let p dle, lamp, or incandescent electric light L. (Shown in dotted lines in Fig. l Startin g from this point, the paper itself is either gradually increased in thickness, darkened in color,

` treated so that it will admit a greater or less all the way from the dimmest possible light i amount ot' light in plat-es, orz'ulditional layers FOO may be used, as shown atpoints F, G, and H, Fig. 3, where two, three, and four layers are indicated, so that less and less light is transmitted through the openings a a as the screen is revolved, until nally, when the four thicknesses, as at H, are over the opening or openings, there is very little if any light transmitted. lf an electric light, L, is used in the interior of the lantern as the source of light, the'entire outside case can be made lighttight except at the openings referred to, and where such a light can be obtained it is by far the best method for this purpose. lf a candle or lamp is to be used as the source of light in the lantern, suitable arrangements must be made for the supply of air and the escape of products of combustion.

Another way of embodying my invention would be to construct the screen B of various colors or various thicknesses or layers of glass or similar material, arranged in panels on the side of a square or hexagonal lantern, which can be Aturned in any desired position.

Still another method of embodying the invention would be to provide an outside case for the lantern, having on one or more sides of it iiXed non-actinic colored screens of any suitable material, as shown in Fig. 4, arranged so that, say, at the bottom d the screens would transmit the least amount of light and at .the top the greatest amount, and intermediate amounts between, and vice versa, and l then provide an outside. curtain, D, or shutter that claim as new, and desire to secure by Letters v l. In a photographic dark-room lamp or lantern, a frame having an opening therein, an d a non-actinic screen made in sections differing in degrees of transparency or translucency to the passage of light.`

2. In a photographic dark-room lamp or lantern, the combination of a source of light, a screen of non-actinic colored material arranged to interpose two or more diierent degrees of transparency or translueency to the passage of light, and an outside case or body provided with one or more openings through which light can be transmitted from within, substantially as set forth.

3. The combination, with a box or casing having one or more openings, of a movable cylinder therein, portions of the outside of which are made up of from oney to several different layers of .non-actinic material, and a source of light within the cylinder, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

GEORGE WV. STOCKLY.

W'itnesses: y

A. D. DORMAN, L. S. NoLD.