Patent GB-330173-A (GB)
Title: Illuminated colour changer for spot and flood lights and the like
IPC: F21S8/00
Filed: 1929-07-23
Abstract: 330,173. Drew, W. S. July 23, 1929. Lantern screens.-In a colourchanging device for theatrical spotlights and other lamps in which a plurality of differently coloured screens are slidably mounted in a casing, the casing carries means which are externally operable from either side of the casing, for selectively sliding any one or more of the screens into and out of the operative position. In the form shown, a unit 10 containing the colour screens and a lamp box 23 are both removably accommodated within a comparatively thin open-sided casing 11 which has a front wall 14 provided at its upper part with a large opening 18 and a hinged rear wall 15 provided with a corresponding opening surrounded by an outwardly extending flange 19 adapted to fit around the spotlight. Gelatine or other coloured transparencies 42 are mounted in apertured frames 39 which are releasably held in carriages 37 by means of spring catches 42<1>, the carriages 37 having eyes 40 which fit loosely around vertical rods 36 detachably mounted on the side walls 12, 13 of the unit 10. The lower edge of each frame 39 is provided with a slotted slide 45 engaged by a small roller 55 which is carried by an operating lever 54 pivotally mounted adjacent the upper end of a brace rod 53 which is rigidly connected to the side wall 12 and to a fixed bar 52 extending across the casing. A bellcrank 57 is pivoted to the brace rod 53 and to a link 56 pivoted intermediate the ends of the lever 54, the link 56 having a stop 58 which prevents movement of the link and the upper part of the bell-crank beyond the position of alignment shown in Fig. 7. The lower end 59 of the bell-crank is connected to a pair of links 60, 61, the latter being pivoted to one end of a lever 62 which is pivoted intermediate its ends to the fixed bar 52 and pivoted at its other end to a link 63. the links 60, 63 are pivotally connected to carriers 47, 48 slidably mounted on a fixed rod 46 and soldered or otherwise secured to pull-rods 50, 51 extending through apertures in opposite sides of the casing and fitted with handles. Any one or more of the screens may therefore be selectively slid into and out of operative position by pulling and pushing on the corresponding rod or rods 50 or. 51. Electric lamp sockets 27 are mounted on webs 28 which have flanges 29 fitting into a pair of inclined guide-ways 26, whereby the lamps may be adjusted to and from the ends of the lamp box 23. These ends are, rounded off and formed of inner and outer walls 33, 34 provided at one end with slots and at the other end with a series of rows of apertures 32, the slots and apertures being in alignment with the various pull-rods 50, 51. Strips 35 of gelatine or like transparent, film corresponding in colours to the transparencies 42 are arranged between the walls 33, 34 to provide coloured indications so that the correct pull-rods may be operated when the device is used in the dark. One of the frames 39 is fitted with an opaque screen for blocking out the light, and the front wall 14 of the casing 11 may be provided with transverse slide-ways 20 to receive an additional colour screen. A remote control may be provided by connecting the pull-rods to solenoids or the like controlled by remote switches.