US1987705A - Flash box - Google Patents

Description

Jan. 15, 1935., T. W. PEbERsE'N 4 1,987,705

FLASH BOX Filed Feb. 6, 1934 NvENToR THOMAS W PEDERE/V .g AT oR'NEY Patented Jan. 15, 1935 UNITED STATES -MTENT ,oF-FcEj Application February 6, 1934, Serial No. 709,933 s claims. c. 240-103) This invention relates to electric advertising and display devices ofthe type known as fiash boxes, in which pictorial or other matter on a screen is intermittently illuminated by an electric lamp in a reflecting box at the back of the screen.

These boxes are usually light tight, to throw all the light out through the screen and so as not to cast light backward, which would be objectionable in certain cases, as for example, when these boxes are used in display windows.

The closing in of the lamps in this way frequently produces over-heating and burning out of the lamp filaments and heretofore it has been necessary to remove the box from the back of the frame carrying the screen or transparency to effect replacement of lamps.

The objects of this invention are to enable quick replacement and changing of lamps without having to take the box apart and to accomplish this with a simple and inexpensive construction, which will not appreciably increase the cost of the structure.

These objects are attained by the novel features of construction, combinations and relations of parts hereinafter described, illustrated and broadly claimed.

The accompanying drawing illustrates simple practical embodiments of the invention, it being understood that the actual physical form may be modified and changed within the true intent and scope of the invention.

Fig. 1 is a perspective view illustrating one of the new light boxes and showing the lamp unit bodily removed as a separate unit.

Fig. 2 is a broken rear view with the removable lamp unit in position in the box.

Fig. 3 is a broken vertical Sectional view as on substantially the plane of line 3-3 of Fig. 2.

Fig. 4 is a broken Sectional detail of a modified form of mounting seat for the removable lamp unit.

In the illustration, the complete box consists of a frame 5, of wood or the like, carrying a screen or transparency 6, and to the back of which there is attached as by nails, screws or other suitable fastenings 7, a reflecting light enclosure 8 of truncated pyramidal form. This light enclosure may be of sheet metal, painted or otherwise interiorly finished to reflect the light forwardly through the screen. The' back wall 9, of the light enclosure is made with an opening 10, large enough to pass the lamp globe 11, which is to be used in the box. About such opening, the back wall is inset to provide an inwardly displaced flange 12 and circularwall 13,' these forming an inwardly displaced annular seat.

The socket 14, in which the lamp is mounted lcarries an outstanding circular flange 15, of slightly less diameter than the circular wall 13, and of a thickness approximating the depth of the inset. Consequently, this flange will rest in the inset seat approximately fiush with the outer surface of the back wall.

For removably securing the socket fiange in its seat in the back wall of the box, there are provided in the illustration, two diametrically opposite lugs 16, supported on the outer face of the back wall, extending radially inwardly over the fiange of the seat and to get by these lugs, the flange is notched in its opposite edges as at 17. By making these lugs of less extent than the width of the seat ilange 10, the notches 17, in the socket flange need not be cut so deep as the width of the seat flange, to thereby leave a light excluding overlap in all positions of the socket fiange on the seat flange, as indicated in Fig. 2.

The holding lugs 16 may be simply short pieces of flat strip material welded or otherwise secured to the back wall in position projecting over the edges of the seat. It is possible also that these securing lugs may be integral parts of the box wall as indicated at 16a in Fig. 4, where such lugs are simply parts of the box wall left standing in the original plane of such wall when the seat flange is depressed, such fiange being interrupted at the points 12a, where these keys are left attached in the original plane of the back wall.

The socket attached flange 15 is indicated as a circular flat plate and thismay beattached to the socket in various ways. In the illustration, the socket is of the separabletype, such as used on electric signs and comprising a base piece 18, carrying the screw contact 19, and a front piece in the form of a collar 20, which screws over the shell contact. This front screw piece has a flange 21, which enters in the back or base piece and as shown in Fig. 3, the mounting flange 15, may be passed over this flange 21, and clamped between opposing portions of the front and back pieces of the socket. This combination enables quick application of the fianges to the sockets and the ready substitution of different kinds of flanges and sockets.

The invention adds but little to the expense of the box structure and adds no bulk to the box. The flange or disc-like member which carries the socket overlaps the depressed flange in the back of the box suiciently to exclude objectionable light at the back and this mounting flange may have a bright finish where it is exposed Within the box, so as to form part of the internal reflecting surface of the box.

What is claimed is:

1. A flash box having a lamp opening in the back wall of the same and having an inwardly depressed fiat annular flange about said opening, a fiat disc-like member of larger diameter than the lamp opening and supportable against Said depressed: annular fiance,, @operating interlocking elements adapted to pass one over the other as said disc-like member is engaged with the-v depressed flange and to interlock upon relative rotation of said disc-like member and box including lugs on the back wall projecting radiallyinward towardthe lamp opening and' ovrstanding the inwardly depressed annul'ar fiange, the fiat disc-like member having substantiallg radial, notches in the edge of the same to pass said lugs mdalamn socket earriedzby said disc-likemember.

2. A flash box having a shallow fiat annular seat sunk in the back wall of the same and an opening through the center of said seat, radially projecting lugs overstanding said shallow fiat seat, a separable lamp socket, a washer-like flange held between the parts of said separable lamp socket and engageable in said seat, said fiange having notches in the edge of the same to pass over said lugs and a lamp carried by said socket of a .size-to pass through said opening, within the seat.

3. A flash box having an opening in the back Wall of the same and having material adjoining said opening depressed to form parts of an annular seat, said depressed portions being discon- Vellt'fld, VW.ith ..l.1g. portions of the box Wall therebetween in substantially the original plane of thebox wall; a dange of a size to seat on said depressed portions and notched in the edges to pass said lug portions and a lamp bulb socket 20 carriedhy said fienge.

THOMAS W; PEDERSEN..

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