Improvements in means for illuminating drawing boards, work benches, display tables, writing desks and like surfaces

Abstract

324,335. Salmon, E. H., and Staples, S. F. Oct. 20, 1928. Shades and reflectors; shade and reflector holders.-For the illumination of flat surfaces, such as a drawing board YWXY, a writing desk, a work bench, or a display table, two or more sources of light, such as incandescent electric lamp bulbs L, are mounted inside a shade or reflector S and screening partitions G, H are arranged between the light sources so as to direct the light in one general direction and to prevent cross-lighting and the casting of a shadow in the direction of the working point of a pen or tool held in the hand, the edge of a T-square or the edge Q R of a set square Q R T. or by two adjacent vertical faces of a rectangular object placed on the surface with two of its sides parallel to the main axis of the shade. The sides of the shade may be straight, as shown in Figs. 2 and 3, or the sides and the partitions may be curved so as to form substantially parabolic reflecting surfaces G<1>, H', as shown in Fig. 6. The axes of the parabolas may be inclined at different angles to the surface, and the bulbs L are placed at or near the foci of the parabolas. The shade may be made of opaque or translucent material, its inner surface preferably being white. It may be shaped so that its sides, if projected, would substantially enclose the surface, and it may be mounted to one side or at one corner of the surface. The top of the shade may be horizontal but it is preferably inclined so as to refleet light towards the centre of the surface. The bulbs L may be of the same or different intensities and are arranged in a line at right angles to the side X of the surface. The partitions may be apaque and may extend for a part or the whole of the depth of the shade. They may be hinged to the top or sides of the shade or made detachable from the shade so that a number of shades may be nested one within the other for transport purposes. A short screen may be adapted to hang from the front edge of the shade while a preferably removable cover of paper or other translucent material may extend over a part or the whole of the open end of the shade so as to soften the light and to exclude dust and dirt. The shade may be carried by a pedestal or bracket, by the conducting flex or other single cord, or by a continuous cord M P N provided with height-adjusting means so that the shade may be raised completely away from the surface. The shade may be weighted to hold it in any desired position and means may also be provided for moving the shade laterally of the surface. For the illumination of large surfaces, two or more such shades may be combined together into a single block.

Claims

Description

Topics

Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (0)

    Title

Cited By (0)

    Publication numberPublication dateAssigneeTitle