US370370A - Camera-plate holder for holding negative-paper - Google Patents

Description

(No Model.)

T. H. BLAIR.

CAMERA PLATB HOLDBR FOR HOLDING NBGATIVE PAPER.

No. 370,370. Patented Sept. 27, 1887.

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THOMAS H. BLAIR, OF BOSTON, MASSACHUSETTS.

CAMERA-PLATE HOLDER FOR HOLDING NEGATIVE-PAPER.

SPBCIFICA'I'ION forming part of Letters Patent No. 370.370, dated September 2'7, 1887.

. Application filed July 23, 1887. Serial No. 245,136. (No model.)

To aZZ whom it may concernz Be it known that I, THoMAs H. BLAIR, a citizen of the United States, and a resident of Boston, in the county of Suflolk and State of Massachusetts, have invented new and useful Improvements in Camera-Plate Holders for Holding Negative-Paper, of which the following, taken in connection with the accompanying drawings, is a specification.

This invention relates to improvements in plate-holders for holding negative-paper, and it is carried out as follows, reference being had to the accompanying drawings, where- Figure 1 represents a front elevation of the invention, showing a portion of the slide as removed. Fig. 2 represents a Vertical section on the line A B, shown in Fig. 1. Fig. 3 represents a cross-section on the line O D, also shown in Fig. 1; and Fig. 4 represents an enlarged longitudinal section of the plate to which the negative-paper is attached.

Similar letters refer to similar parts wherever they occur on the different parts of the drawings.

The plate-holder frame is composed of the side pieces, a a, the bottom piece, a', and top or head piece, a, as shown, secured together in such a manner as to form a square or rectangular inclosure that is. open from front to rear, and is without any stationary diaphragm or division-wall. The head a is slitted for the reception of the slides b 1),, which are guided in grooves in the interior portions of the bottom and side pieces, a' a a, as is common in camera-plate holders.

b b3 are the bars or handles, secured in a suitable manner to the upper project-img ends of the slides b b', as shown in Figs. 1 and 2.

cin Figs. 2, 3, and 4 is the plate to which the sheet of negative-paper d is temporarily secured, and for this purpose I make a slit or groove, c', in one end or side of such plate o, as shown in upper end of Fig. 4, and in such slit I introduce one end of the negative-paper d, which is afterward wrapped smoothly around the two opposite sides of the said plate c and carried far enough to lap over the slittedportion c', as shown in Fig. 4, thus providing the plate c with a sensitive negative-paper surface on two of its sides for the taking of two different exposures.

To the interior portion of the bottom piece,

a, of the plate-holder frame I secure a metal spring, e, forlholding the plate c in positionv when introduced in the plate-holder, as shown in Figs. 1 and 2.

At the junction of side pieces, a a, and bottom piece, a, I insert in miter slits made through such parts the venecrs f and a portion of which projects inside of the parts a a and a' and serves as guides between which the lower end of the plate c is inserted and held in its proper place, as shown in Figs. l, 2, and 3.

Between the slides b and b', I make on the interior of the frame a a a', nearest to the slide b', a rib or projection, af, that serves as arigid bed or support for the plate o when inserted within the holder, as shown in Figs. 2 and 3, and the said bed or rib a* also serves to prevent the light on the side of the negative-paper that is being exposed from passing to the opposite side of such negative-paper.

In a slit in the under side of the top piece, a', of the plate-holder frame I secure a pair of flexible cloth or rubber fiaps, g g, (shown in Fig. 2,) which, when the slides are drawn,

,serve to close the slits in the top piece, w, as

is common in plate-holders.

h h are suitable packings arranged in grooves in' the head or top piece, a', for preventing the light from entering through the slits in the said top piece, ct', when any of the slides are drawn out in the usualvmanner.

In using this my improved plate-holder I proceed as follows: After having secured the negative-paper d to the two opposite sides of the plate c, I draw out the slide b and insert the lower end of the plate c in the space between thelower projections, f f ',with its lower edge resting on the yielding spring e, and depress the latter until the upper end of the plate c will pass below the interior lower portion of the top piece, a', when I press the plate c into the holder until one of its sides is made to rest against the rib or ridge af, as shown in Figs. 1, 2, and 3, when the plate c will be held firmly in position, as shown in Figs. 1 and 2, by the spring e pressing its upper end with a proper frictional resistance against the under side of the head a', after which the slide b is closed, as shown.

In this manncr I produce a very light and durable double plate-holder having a central rco plate provided with sensitve negative-paper on two of its opposite sides, as shown and described. After the negative-paper has been exposedin a camera as usual and the plate-holder taken to the dark room, IWithdraw the sldes b b' and remove the platec and its paper (Z simply by moving the upper end of said plate a little to the left (in Fig. 2) until it comes to one side of the head-piece a', after which it can easily be drawn out of the plate-holder and the paper removed from the plate c and another strip put on it, and so on.

Having` thus fully described the nature, construction, and operation of iny invention, I Wish to secure by Letters Patent, and elaim- 1. In aplate-holder for negative-paper, the plate c, having a slit, of, in one of its ends or sides adapted to receive one of the ends of the negative-paper d, combined With the latter Wrapped around it, as and for the purpose set forth.

2. rhe frame a a a' a, open from side to side and provided With the sldes Z) b', and having` lower guides, ff', the rest or rib at, and spring a, combined with the detaehable plate c, having` a slit, c', in one of its sides or ends for seeuring to it the negative-paper (Z, as and for the purpose set forth.

3. The frame a a a' a, open 'from side to side and provided With slides Z) i), combined With the deta-ehable plate o, upon which the nega tive-paper is Wrapped orsecured on both sides of said plate, for the purpose set forth.

In testimony whereof I have signed my name to this specification, in the presenee of two subseribing witnesses, on this 12th day of July, A, D. 1887.

THOMAS H. BL AIR.

'Witnessesz ALBAN ANDRN, HENRY CHADBOURN.

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