US1792295A - Photographic-film pack - Google Patents

Description

Feb. 10, 1931.

Filed Jan.

H.T.GASEUHNE PHOTOGRAPHIC FILM PACK Patented Feb. 10, 1931 UNITED STATES PATENT OFFICE HERBERT TENNYSO'N GASELTINE, F WEMBLEY PARK, ENGLAND, ASSIGNOR TO THE IMPERIAL DRY PLATE COMPANY LIMITED, OF LONDON, ENGLAND, A BRITISH COM- PANY PHOTOGRAPHIC-FILM PACK Application filed January 10, 1929, Serial No. 331,531, and in Great Britain January 19, 1928.

This invention relates to photographic film packs of the kind in which the films are attached to flexible draw-tabs which enable them to be drawn from a front exposure com partment to a rear storage compartmeiit, one at a time, round the end of a lilnrsupportin g frame.

The draw-tabs extend outside the lilm-container or casing and are threaded through a li ht-trap, and the object of this invention is to provide an improved light-trap.

This improved light-trap is of the kind which includes a. strip of paper or like material located in the rear storage compart- F ment of the casing and having a transverse slit therein through which the draw-tabs are threaded from back to front.

Hitherto such light-traps have included a velvet pad secured to the strip adjacent the slit or a reinforcing patch of paper, fabric or other material stuck to the paper or like strip (the slit extending through such patch) for the reason that paper of the character otherwise desirable is not thick enough to constitute by itself an efiicient light-trap.

According to the principal feature of the present invention a light-trap of the kind referred to is constituted by at least two layers of paper or like material each provided with 30 a transverse slit, said layers being separate from one another (that is, not stuck together) in the region of the slit.

Preferably, three layers are employed and they may be provided by folding a single strip of paper or the like in the manner of a flattened letter N. The slits in the three la ers may be in register with one another or may be relatively displaced by a small amount transversely of their length.

A preferred embodiment of the invention will now be described by Way of example with reference to the accompanwing drawings, in which: I

Figure 1 is a perspective view of the im- 45 proved light-trap, and I Figure 2 is a side elevation in section of a film-pack with the light-trap in place.

Figure 3 is a perspective view of an alternative form of the improved light trap.

A strip 26 of opaque paper the full Width of the interior of the casing, is folded at one end over the upper edge of the front lihnsupporting plate 10, bent round the lower ends 14 and 16 of the two supporting plates and extends up the back of the rear plate 12. At a point well above the top of the rear plate it is folded on itself forwardly, and the folded-over portion is again folded upwardly along a line below the top of the rear plate.

These two folds 28, give this part of the strip the form of the letter N, the first stroke of which is extended in the downward direction;

The three layers of paper corresponding to the three strokes of the N are slit transversely in register, as at 32, the length of the slits being very slightly greater than the width of the film-tabs 34. The edges of the three slits constitute an efiicient light-trap, the resilience of the three layers keeping these edges in close contact with the surfaces of the tabs. The tabs 34 are passed from back to front through the slits as clearly shown in Figures 1 and 3 and therefore their protruding ends are in front of the part 30 of the paper strip corresponding to the third stroke of the N. This part of the strip is folded backwards and downwards and extends within the casing 22 behind the film-tabs to a point near the lower end of the casing. This downwardly-folded part is indicated at One of the two tabs 34 shown is part of a front safety-cover 38 of double thickness, and the other is part of a paper backing 40 for a film 42. Only one such film is shown, for the sake of clearness; in practice there will be several films each attached to a paper backing and film-tab.

Theportion of the paper strip 26 which is folded over the top of the front plate 10 is folded upwards again as indicated at 44, Figure 3, and is then bent forwardly to form a flap 46 which lies immediately underneath a flange 18 or the rear plate 12 and the free edge of which abuts against the front wall of the casing 22. This flap protects the films 42 from light which might leak in from above.

Although a light-trap consisting of. three layers of paper is preferred, it is within the invention to provide two layers only, as may conveniently be done by singly folding the paper strip. This modification is illustrated in Figure 3 of the accompanying drawings. In this case the function of the part of the strip which is finally folded over, inthe form first d'escribedthat is to say the exclusion of light which would otherwise enter the film-tab aperture in the casing-is fulfilled by a separate sheet of paper 29.v

It will be understood that the two or three layers of paper need not be constituted by different parts of a single strip brought together by folding, but may be;- separate sheets secured together or not.

I claim-- 7 1. For a photographic film-pack, a lighttrap comprising at least two layers, of opaque paper each havinga transverse slit for the passage of the film-tabs, said layers being separate from one another in the region of theslits.

2. For a photographic film-pack, a lighttrap comprising asinglestrip of paper folded to provide atleast two adjacent layers each havinga transverse slit therein for the passage of the film-tabs.

3. For a photographic film-pack, a lighttrap comprising a single strip of paper folded in the manner of the letter N to provide three layers adjacent to one another each having a transverse slit therein for the passage of the film-tabs.

4 In combination with a photographic film-pack, a light-trap comprising a. single strip of paper folded in the manner of the letter N to provide three layers adjacent to one another each having a, transverse slit therein for the passage of the film-tabs that part of the strip corresponding to the first stroke ofthe N being extended around both sides of the film-supporting frame between said frame and the films and draw-tabs.

5. In combination with a photographic filnrpack, a light-trap comprising a single strip of paper folded in the manner of the letter N to provide three layers adjacent to 7 one, another each having aftransverse slit therein for thepassage of the film-tabs that part of the strip oorrespondingto the firs stroke of the N beingextended aroundibioth sides of the film-supporting frame between said frame and the films and draw-tabs, folded back and down over the upper edge of the front plate of said frame, then folded upward'ly and finally bent forwardly to constitute a flapio verlying theupper edges of the films in thef-ront compartment of the pack.

6'. For, a photographic film-pack, a lighttrap comprising-a single strip ofpaperfoldedwinthe manner of the letter N to provide three layers adjacent to; one-;anot;her'each having a transverse slit therein for the passage of; the film-tabs that part of the strip corresponding to the last stroke of the N being extended and folded back over the top fold.

7. In combination with a photographic film-pack, a light-trap comprising a single strip of paper folded inthe manner of the letter N to provide three layers adjacent to one another each having a transverse slit therein for the passage of the film-tabs that part of the strip corresponding to the last stroke of the N being eXt'ended and folded back over the top fold and that part of the strip corresponding to the first stroke of the N being extended around both sides of the film-supporting frame between said frame and the films and draw-tabs. V

In testimony whereof I afiix my signature.

- HERBERT TENNYSON GASELTINE.

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