GB1603529A - Filming light - Google Patents

Abstract

A protective basket (3), in the shape of a semicircular cylinder and made from glass, around the incandescent lamp (13) and in front of the reflector opening protects the user without restricting the light cone ( alpha 1) of the film luminaire. <IMAGE>

Description

(54) A FILMING LIGHT (71) I, HANS-GUNTER BAUSCH, a Ger man citizen, of Westerwaldstrasse 214 z16, 6250 Limburg, Federal Republic of Germany, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a filming light comprising a casing accommodating the light fitting and, if required, a cooling fan, a handle disposed on the casing, and a protective cage covering the light exit aperture, the light fitting comprising a lamp and a reflector of preferably parabolic cross-section.

Incandescent lamps are normally used as the light source in filming lights and they assume very high temperatures during operation. A cooling fan is therefore frequently provided to enable the light to be used for a relatively long period. Due to the very high operating temperatures, there is a risk of the incandescent lamp of a filming light bursting and pieces of glass which explode from the lamp may cause injuries. To prevent this, a protective cage can be provided to prevent such pieces of glass from being discharged from the filming light. There is a statutory requirement that filming lights must be provided with such a protective cage.

Protective cages of the kind used heretofore, e.g. as disclosed by German Utility Model 7521 149, have the disadvantage of excessively limiting laterally the cone of light originating from the light source and emitted by means of a preferably parabolic reflector.

Consequently, with a filming light of this kind only a relatively small angle of a scene can be illuminated.

The object of the invention is to make available of filming lamp with a protective cage allowing wide-angle emission of the light.

To this end, according to the invention, the protective cage is formed by a transparent glass semi-circular cylinder disposed over the reflector opening.

Advantageous developments of the filming light according to the invention are characterised in the sub-claims.

Since the protective cage in the filming light according to the invention is constructed as a glass member of semi-circular cylindrical shape, it does not obstruct the light emission so that an emission angle of about 160 is possible for the light from the light source. To enable the light to be emitted over a narrower angle if required, in a development of the filming light according to the invention, movable masks are provided by means of which the light emission angle can be limited to varying degrees if only a smaller portion of a scene is to be illuminated.

The invention will be explained in detail hereinafter with reference to embodiments illustrated in the accompanying drawing wherein: Fig. 1 is a side elevation of a first embodiment of a filming light according to the invention.

Fig. 2 is a cross-section through the filming light of Fig. 1 on the line 11-Il.

Fig. 3 is a plan view of the filming light in the direction of the arrow III in Fig. 1 and Fig. 4 is a side elevation of another embodiment of a filming light according to the invention.

Fig. 1 is a side elevation of a filming light comprising a lamp body accommodated in a casing 1. The latter has a light exit aperture covered by a transparent glass protective cage 3 of semi-circular cylindrical shape. A motor-driven cooling fan is accommodated in a bottom part 5 of the casing to cool the incandescent lamp used as light source. A handle 7 is provided on the casing 1 and a base 9 containing a screw 11 to receive a stand is provided at the bottom part of the casing.

As will be seen from the cross-sectional view in Fig. 2, the casing 1 is also of semicircular cylindrical shape and together with the protective cage 3 of the same shape forms a circular cylinder. Inside this cylinder is an incandescent lamp 13, which is used as light source and the light of which is emitted through the cage 3 by means of a reflector of parabolic cross-section. A light emission angle of about 160 is possible by means of the semi-circular cylindrical construction of the glass cage 3.

To enable this emission angle to be reduced if required, masks 17, 17 are provided on the inner wall of the circular cylinder formed by the casing 1 and the cage 3, in the region of the transitions between these parts where they extend in parallel relationship to the cylinder axis. The masks are in the form of portions of a cylindrical wall and are pivotable, preferably about an axis of rotation situated on the cylinder axis, on one or both ends of the cylinder formed by the casing 1 and the cage 3. The length of the masks, 17, 17 is at least equal to the height of the cylinder of the cage 3. Actuator pins 21 are fixed to the masks 17, 17 and are each guided in a slot 23 extending in the peripheral direction of the semi-circular cylinder of the casing and outside the latter they merge into an actuator button.

The two masks may, for example, be automatically synchronized, e.g. by means of a gear or transmission on the pivot axis 19, so that when one of the masks is - moved by mean of its actuator button 21 the other masks is pivoted to the same extent.

Fig. 3 is a plan view of the filming light described, viewing in the direction of arrow III in Fig. 1.

To enable a subject to be illuminated either directly or indirectly at will by means of the filming light, the casing 1 can be pivoted about a pivot axis 25 extending perpendicularly to the cylinder axis. Since, even if a cooling fan is used, the lamp casing usually is very hot when the filming light has been on for some time, the casing is advantageously pivoted by means of a motor to obtain direct or indirect subject illumination.

The fan motor which is usually provided in any case can be used for this purpose. Fig. 4 shows an embodiment of a filming light of this kind in which those parts corresponding to the parts of the first embodiment have been given the reference numerals used in Figs. 1 to 3 and are not explained again. A motor and transmission chamber 27 connected to the peripheral wall of the semicircular cylindrical casing 1 contains a cooling fan 29, a fan motor 31, a transmission 33, and a control cam 35. These are shown only diagrammatically in Fig. 4, the fan motor 31 being indicated by broken lines and the cam 35 by chain-dotted lines. The transmission 33 includes a coupling by means of which the drive for pivoting the light can be coupled as required to the fan motor 31.

WHAT I CLAIM IS: 1. A filming light comprising a casing accommodating the light fitting and, if required, a cooling fan, a handle disposed on the casing, and a protective cage covering the light exit aperture, the light fitting comprising a lamp and a reflector of preferably parabolic cross-section, characterised in that the protective cage is formed by a transparent glass semi-circular cylinder disposed over the reflector opening.

2. A filming light according to claim 1, characterised in that the casing is also of semi-circular cylindrical construction and together with the cage of the same construction forms a circular cylinder surrounding the lamp and the reflector, and masks are provided on the inner wall of the circular cylinder near the transitions between the casing and cage semi-circular cylinders, where they extend parallel to the cylinder axis, each mask being movable a certain amount in the peripheral direction of the cylinder to enable the light emission angle of the light source to be limited.

3. A filming light according to claim 2, characterised in that the masks are each pivotable about an axis of rotation situated substantially on the cylinder axis and each has an actuator pin which is guided in a slot extending in the circumferential direction of the semi-circular cylinder forming the casing, and merges into an actuator button outside the casing.

4. A filming light according to any one of claims 1 to 3, characterised in that the casing is pivotable together with the light fitting about an axis of rotation extending perpendicularly to the cylinder axis.

5. A filming light according to claim 4, with a cooling fan motor, characterised in that a transmission is provided which is adapted to be coupled to the cooling fan motor and which, when coupled, pivots the casing together with the light fitting.

6. A filming light substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. the semi-circular cylindrical construction of the glass cage 3. To enable this emission angle to be reduced if required, masks 17, 17 are provided on the inner wall of the circular cylinder formed by the casing 1 and the cage 3, in the region of the transitions between these parts where they extend in parallel relationship to the cylinder axis. The masks are in the form of portions of a cylindrical wall and are pivotable, preferably about an axis of rotation situated on the cylinder axis, on one or both ends of the cylinder formed by the casing 1 and the cage 3. The length of the masks, 17, 17 is at least equal to the height of the cylinder of the cage 3. Actuator pins 21 are fixed to the masks 17, 17 and are each guided in a slot 23 extending in the peripheral direction of the semi-circular cylinder of the casing and outside the latter they merge into an actuator button. The two masks may, for example, be automatically synchronized, e.g. by means of a gear or transmission on the pivot axis 19, so that when one of the masks is - moved by mean of its actuator button 21 the other masks is pivoted to the same extent. Fig. 3 is a plan view of the filming light described, viewing in the direction of arrow III in Fig. 1. To enable a subject to be illuminated either directly or indirectly at will by means of the filming light, the casing 1 can be pivoted about a pivot axis 25 extending perpendicularly to the cylinder axis. Since, even if a cooling fan is used, the lamp casing usually is very hot when the filming light has been on for some time, the casing is advantageously pivoted by means of a motor to obtain direct or indirect subject illumination. The fan motor which is usually provided in any case can be used for this purpose. Fig. 4 shows an embodiment of a filming light of this kind in which those parts corresponding to the parts of the first embodiment have been given the reference numerals used in Figs. 1 to 3 and are not explained again. A motor and transmission chamber 27 connected to the peripheral wall of the semicircular cylindrical casing 1 contains a cooling fan 29, a fan motor 31, a transmission 33, and a control cam 35. These are shown only diagrammatically in Fig. 4, the fan motor 31 being indicated by broken lines and the cam 35 by chain-dotted lines. The transmission 33 includes a coupling by means of which the drive for pivoting the light can be coupled as required to the fan motor 31. WHAT I CLAIM IS:

1. A filming light comprising a casing accommodating the light fitting and, if required, a cooling fan, a handle disposed on the casing, and a protective cage covering the light exit aperture, the light fitting comprising a lamp and a reflector of preferably parabolic cross-section, characterised in that the protective cage is formed by a transparent glass semi-circular cylinder disposed over the reflector opening.

2. A filming light according to claim 1, characterised in that the casing is also of semi-circular cylindrical construction and together with the cage of the same construction forms a circular cylinder surrounding the lamp and the reflector, and masks are provided on the inner wall of the circular cylinder near the transitions between the casing and cage semi-circular cylinders, where they extend parallel to the cylinder axis, each mask being movable a certain amount in the peripheral direction of the cylinder to enable the light emission angle of the light source to be limited.

3. A filming light according to claim 2, characterised in that the masks are each pivotable about an axis of rotation situated substantially on the cylinder axis and each has an actuator pin which is guided in a slot extending in the circumferential direction of the semi-circular cylinder forming the casing, and merges into an actuator button outside the casing.

4. A filming light according to any one of claims 1 to 3, characterised in that the casing is pivotable together with the light fitting about an axis of rotation extending perpendicularly to the cylinder axis.

5. A filming light according to claim 4, with a cooling fan motor, characterised in that a transmission is provided which is adapted to be coupled to the cooling fan motor and which, when coupled, pivots the casing together with the light fitting.

6. A filming light substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.