US2101122A - Light intensity indicator - Google Patents

Description

Dec. 7. I937. 5, woon's 2,101,122

LIGHT INTENS ITY INDICATOR Filed March 8, 1955 3 Sheets-Sheet 1 37 lJa a. a. 11/002505 I00 41/ BY ATTORNEY Dec. 7, 1937.

C. S. WOODSIDE LIGHT INTENS IT Y INDICATOR Fil ed March a, 1955 s Sheets-Sheet 2 if Huh, unmmm .Hmmrmmmh.h,

ATTORN Dec. 7, 193 7.

c. s. WOOD SIDE LIGHT INTENSITY INDICATOR Filed March 8, 1935 5 Sheets-$heet 3 un, I II M ATTORN Patented Dec. 7, 1937 UNITED STATES LIGHT INTENSITY INDICATOR Cornelius S. Woodside, Verona, N.J., assignor,

by mesne assignments, to Westinghouse Electric and Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 8, 1935, Serial No. 9.991

5 Claims.

This invention relates to a device for making visible determinations of variations in the intensity of light and more particularly to'a device whereby an incandescent lamp of a selected wattage may be employed to determine the proper wattage lamp to be used to produce a selected intensity of light.

It has been found that the average person using incandescent lamps, particularly when such lamps are in an elevated fixture, as for example one of the bridge lamp type, finds it difficult to determine the proper wattage lamp to be used to give the correct intensity of light for the purpose intended, as for example for reading.

It is the desire of the lamp manufacturer as well as the distributors to furnish lampsgiving sufficient light for the purpose intended and to also aid the customer in avpiding the use of lamps which give an excessive amount of light with the added expense of current. consumed.

Furthermore, it is desirable to furnish a purchaser with a lamp of sufiicient wattage to avoid eye strain.

The present invention, therefore, relates to a portable device which may be used in connection with the saleof standard lamps and consists of a housing in which an incandescent lamp of a selected wattage is disposed. The housing is provided with a light-receiving surface and between the surface and the lamp is disposed an adjustable diaphragm which varies the intensity of the light so that the purchaser may examine a page of reading matter with light of different intensities and determine which intensity of light is most suitable for the individual need.

' In the construction herein provided a sheet of translucent or light-diffusing material is disposed between the lamp and the illuminated surface.

Means are provided for varying the light transmitting area of. the light diffusing material which means are so arranged and adjustable that the degree or intensity of light passing through the translucent medium is indicated by a measurement in the form of the wattage of the lamp, which'under the reading conditions in which the lamp is to be used will give such intensity.

It is an object of the present invention, therefore, to provide a simple and effective device for determining the particular wattage lamp to be used under predetermined conditions.

Another object of the invention is to provide a convenient portable light intensity indicating apparatus so arranged and constructed that a given light intensity will be indicated or represented by reference to 'a given wattage lamp.

A further object of the invention is to provide a light indicating measuring device in the form of a foldable housing which may be easily disassembled for shipment and quickly and conveniently assembled for use.

Other objects and advantages of the invention will be more clearly understood from the following description, together with the-accompanying .drawings in which:

Fig. 1 is a perspective view of the apparatus in position for operation;

Fig. 2 is an enlarged vertical sectional view taken on the line II-II of Fig. 1;

Fig. 3 is a sectional view taken on line III-III in Fig. 2, looking in the direction of the arrows;

Fig. 4 is a perspective view of the several parts of the apparatus showing a lower frame removed and indicating, in dotted lines, the housing folded or knocked down preparatory to storage or shipment;

Fig. 5 shows the platform, or the part forming Fig. 6 shows the entire structure packed and a container.

The selected embodiment of the invention may, as shown, comprise a foldable housing In having a rectangular base or supporting frame 11. The housing is provided with a light-receiving surface l2 which is disposed at a convenient angle for observation. Above the surface l2 is a partition 13 and a platform 14 having a plurality ofapertures I6. A sheet of translucent or light-diffusing material I1 is disposed beneath the platform covering the apertures 16. The apertures 16 are in the form of sectors and a. disk I8, pivoted at 19 on the platform, is provided with apertures 2|, similar to the apertures 16, and arranged to coincide therewith upon adjustment of the disk about its pivot. A hand piece 22 is provided for adjusting the disk.

An incandescent electric lamp 22' may posed in the upper portion or light housing 23, an aperture 24 being provided to receive the lamp socket. When the lamp is lighted, light rays are transmitted through the translucent material l1, and the disk l8 may be adjusted to permit the be disapertures 16 to be fully exposed and transmit the maximum amount of light or the disk may be I rotated to cut down the amount of light passing through the translucent material. Thus the intensityof the light falling on the surface 12 is varied. A sheet of reading matter 23' or other seeing task may be placed on the surface l2 and.

through a slot 28 in the wall 25, and the marks 21 indicating the various wattage lamps are calibrated. As the disk is turned the light intensity is varied. The light falling-on the surface 12 will have the intensity of the lamp indicated when the marker on the hand piece registers with the marking line indicating a particular wattage lamp.

It is to be understood that the lamp selected for use in connection with the present device may be of a predetermined wattage as for example a 60-watt lamp may be used and the light intensity measured with diiferent positions of the disk of diaphragm to obtain the marks representing the different wattage lamps.

The present device is used to determine the proper intensity of light for lamps which are positioned a considerably greater distance from the user than the distance between the light receiving surface I2 and the lamp 22. Thus, if the distance at which a lamp is to be used is from three to four feet from the surface illuminated it will be evident that by means of the present device a lamp of 60 watts, for example, may be employed to indicate the intensity of light obtained from a or watt lamp at a greater distance.

The present invention provides a portable structure which consists essentially of the frame i i and the part providing the removable surface l2. The frame is provided with ears 3| for insertion into slots 32. The part with the surface I2 is provided with a lower flap 33 which may be inserted between an inclined floor 34 and an outer side 35 of the frame. The platform I3 is provided with side flaps 36 which may be riveted to the side walls 31 and 38 of the housing, and the front wall 25 of the housing is foldable and provided with a cut-out portion 39 which, in conjunction with the platform [3, provides the slot 28 to allow for movement of the hand piece of the disk.

An extension flap 4| may be provided on the portion M to receive descriptive or advertising matter. A rear wall 42 is provided for the light chamber 23, which wall is provided with flaps for retaining it in position.

When it is desired to ship the device, the frame II and the surface element l2 may be removed. The walls 25 and 42 may then be folded inwardly beneath the top wall of the housing and the housing collapsed as shown in dotted lines. It

. is particularly applicable to lamps sold under the trade name Mazda:

Although a preferred embodiment of the invention is shown and described herein it is to be understood that modifications may be made therein without departing from the spirit and scope of the appended claims. What is claimed:

1. A light intensity indicator comprising a housing having an upper chamber with a closed front wall, a lower chamber with a large front opening, a light source in said upper chamber, a member in said lower chamber adapted to receive light from said upper chamber and support a s e e i ng task for inspection through said opening, means between said chambers and movable intermediate said light source andsurface for varying the intensity of light illuminating said surface, and means indicating the degree of intensity of light falling on said surface or seeing task in terms of lamp wattage.

2. A light intensity indicator comprising a housing having an upper chamber with a closed front wall, a light source received therein, said housing also having a lower chamber with a large front opening, a member in said lower chamber adapted to receive light from said upper chamber and support a seeing task for inspection through said opening, a wall separating said chambers, apertures in said wall, a light-diffusing material over said apertures, an opaque member movable over said apertures to vary the intensity of light from said upper chamber falling on said surface, and means for indicating the intensity of the light on said surface in terms of lamp wattage,

3. A light intensity indicator comprising a housing having an upper chamber with a closed front wall, alight source in said chamber, a lower chamber in said housing and provided with a large front opening, and a member having a light receiving surface, and adapted to support a seeing task for inspection through said opening, a

wall separating said chambers, apertures in saidwall, light diffusing material over said apertures,v

an opaque member movable over said apertures to vary the intensity of light from said upper chamber falling on said surface, and means for moving said member, said means indicating the wattage of a lamp giving a similar intensity of light under selected conditions.

4. A light intensity indicator comprising a housing having an upper chamber with an opaque front wall, an incandescent electric lamp of a given wattage in said chamber, a lower chamber in said housing and provided with a large front opening, a wall in said lower chamber providing an upper surface receiving light from said upper chamber and adapted to support a seeing task for inspection through said opening, a partition dividing said chambers, a plurality of radially disposed apertures in said partition, light translucent material closing saidapertures, a disc having radial apertures corresponding to said partition apertures and separatedby opaque sec-. tions, means for rotating said disc to cause the opaque sections to vary the effective light transmitting areaof said partition apertures to correspondingly varythe intensity of light falling upon said surface or seeing task, and means for indicating the intensity of said light in terms of lamp wattage.

5. A light intensity indicator comprising a housing having an upper chamber with a light excluding front wall, an incandescent electric lamp of a given wattage in said chamber, a lower chamber in said housing and formed with a large front opening, a wall in said lower chamber providing an upper surfacereceiving light from said upper chamber and adapted to support a seeing task for inspection throughsaid opening, a partition dividing said chambers, a plurality of radially disposed apertures in said partition, light translucent material closing said apertures, a disc having radial apertures corresponding to said partition apertures and separated'by opaque sections, and means for rotating said disc to move said opaque sections to close the partition apertures to. a greater or less degree and vary the intensity of light passing therethrough and falling on said surface.

CORNELIUS S. WOODSIDE.

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