US3612850A - Photoflashlamp holder - Google Patents

Abstract

A flashcube having a plurality of flashlamps, a reflector secured adjacent each lamp, and a transparent mass such as plastic surrounding and embedding each lamp for providing protection against possible explosion of the lamps.

Description

United States Patent [72] Inventors Louis Marius Nijland;

[56] References Cited UNITED STATES PATENTS 4/1966 Anderson et Wilem Westerveld, both of Emmasingel, Eindhoven, Netherlands 822,679

3,244,087 3,327,105 6/1967 Kottler et a1... 3,350,551 10/1967 Whitehead FOREIGN PATENTS 6,515,442 5/1967 Netherlands.................

Primary Examiner-Samuel S. Matthews Assistant ExaminerFred L. Braun Attorney-Frank R. Trifari [21] Appl. No.

[22] Filed May 7,1969

[45] Patented Oct. 12, 1971 [73] Assignee U.S. Philips Corporation New York, NY. May 11, 1968 Netherlands 6806733 [32] Priority [54] PHOTOFLASHLAMP HOLDER 9 Claims, 2 Drawing Figs.

ABSTRACT: A flashcube having a plurality of flashlamps, a reflector secured adjacent each lamp, and a transparent mass such as plastic surrounding and embedding each lamp for providing protection against possible explosion of the lamps.

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PATENTEUUBT 12 Ian 3,512,850

INVENTORS. LOUIS M. NULAND WILLEM WESTERVELD BY 425 2 z GENT PHOTOFLASHLAMP HOLDER The invention relates to a device such as a flashlamp unit having several photoflashlamps of the combustible type which can be ignited successively. There is a tendency to reduce the dimensions of photoflashlamps for devices of this kind more and more, and to increase proportionally thereto the gas pressure in photoflashlamps. The risk of explosion upon ignition of such lamps becomes therefore increasingly greater and single or multiple lacquer coatings provided on the envelope do not provide sufficient protection against glass splinters being hurled away. In flashlamp units and other devices in which the flashlamps are located closely together, damage of the device and of the reflectors may thus occur, in addition to other dangers from explosions.

It has been proposed to place separate sleeves of synthetic material and a comparatively large thickness around the flashlamps of the combustible type. However, the advantage of saving of space obtained by using smaller flashlamps is then largely lost again.

An object of the invention is to prevent explosions in a reliable manner, in devices comprising several photoflashlamps of the combustible type. Such small flashlamps (envelope content l.25 cm and less) have a pressure of the filler gas ranging from high to very high, (for example, oxygen having a filling pressure of from 5 to 30 atm.). It was found that this requirement may be met by a device comprising photoflashlamps which is characterized in that the photoflashlamps are embedded in transparent synthetic resin. The device according to the invention may be obtained in a particularly suitable manner by embedding the photoflashlamps by molding in an acrylate resin.

Acrylate resins are understood to mean resins which are obtained by polymerization of acrylic acid, of methacrylic acid, or the esters of these acids such as the methyl, ethyl and butyl esters. Polymerization may be effected by addition of an organic peroxide to the relevant monomers, or by heating the monomers or exposing them to ultraviolet light.

In a preferred embodiment of a method of manufacturing devices according to the invention, the photoflashlamps are molded in an acrylic monomer, which is subsequently caused to polymerize. The device according to the invention may have different shapes such as cubical, boxlike and cylindrical, and reflectors may be embedded together with the photoflashlamps. By choosing a suitable shape the device may be provided with lenticular curved surfaces to concentrate the light irradiated by the flashlamps for securing the device to a camera, a shoe or an adapter is provided.

In addition it is possible to color the synthetic resin blue by means of an appropriate pigmentation agent such as ferric ferrocyanide and zapon violet. As a result it is not necessary to provide the lamp with a blue colored coating.

In order that the invention may be readily carried into effect, a few embodiments thereof will now be described in detail by way of example, with reference to the accompanying diagrammatic drawing which shows a device in the form of a flashlamp unit.

FIG. 1 is a side view of a device according to the invention,

and

FIG. 2 is a section taken on the line l-I of the device shown in FIG. 1.

In FIGS. 1 and 2 a flashlamp unit is provided with four photoflashlamps of the combustible type la, lb, lc, Id a reflector of aluminum foil 2 is located behind each flashlamp, and the lower end of the device is provided with a base 3. The flashlamps and the reflectors are embedded in transparent acrylate resin, and the base 3 is also formed during molding.

The device may be obtained as follows. The lamp 1a to ld inclusive and reflectors 2 are placed in a mold. Subsequently the mold is filled up with methyl methacrylate monomer to which 0.001 to 0.1 percent by weight, usually 0.01 to 0.l percent by weight of benzoyl peroxide has been added, dependent on the desired rate of hardening. When adding approximately 0.05 percent by weight of benzoyl peroxide, the

monomer polymerizes within 15 to 30 minutes at 20 C. to a solid polymer and a solid flashlamp unit is obtained. To

enchance the mechanical properties, up to approximately 40 percent by weight of a plasticizer, for example, dibutyl phythalate may be added to the monomer.

The present invention particularly provides the following advantages relative to similar devices in which the photoflashlamps and reflectors are accommodated in a transparent sleeve provided with a base portion and a base. This new device forms a robust unit which cannot easily be damaged and in which unlacquered photoflashlamps may be accommodated which otherwise would explode upon ignition; also lacquered lamps may be used. As a result, the use of small to very small photoflashlamps having a large light output becomes possible in flashlamps units.

We claim:

1. A photoflash device comprising a. a base,

b. at least one flash lamp secured to the base,

c. a reflector disposed adjacent each lamp and secured to the base, and

d. a transparent solid mass substantially surrounding and embedding each lamp, for providing protection against possible explosion of said lamps.

2. A device as defined in claim 1 wherein said mass is a synthetic resin.

3. A device as defined in claim 2 wherein said mass is an acrylate resin.

4. A device as defined in claim 2 wherein said resin is molded about said lamps.

5. A device as defined in claim 2 wherein said mass comprises a methyl methacrylate monomer with benzoyl preoxide.

6. A device as defined in claim 5 wherein each reflector comprises a piece of aluminum foil.

7. A device as defined in claim 1 wherein said mass has outer surfaces about each lamp formed as a lens.

8. A device as defined in claim 1 wherein said mass has a blue color for filtering the light.

9. A device according to claim 1 wherein said mass is molded about all the lamps and reflectors.

Claims (9)

1. A photoflash device comprising a. a base, b. at least one flash lamp secured to the base, c. a reflector disposed adjacent each lamp and secured to the base, and d. a transparent solid mass substantially surrounding and embedding each lamp, for providing protection against possible explosion of said lamps.

2. A device as defined in claim 1 wherein said mass is a synthetic resin.

3. A device as defined in claim 2 wherein said mass is an acrylate resin.

4. A device as defined in claim 2 wherein said resin is molded about said lamps.

5. A device as defined in claim 2 wherein said mass comprises a methyl methacrylate monomer with benzoyl preoxide.

6. A device as defined in claim 5 wherein each reflector comprises a piece of aluminum foil.

7. A device as defined in claim 1 wherein said mass has outer surfaces about each lamp formed as a lens.

8. A device as defined in claim 1 wherein said mass has a blue color for filtering the light.

9. A device according to claim 1 wherein said mass is molded about all the lamps and reflectors.

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