Wearable device for monitoring momentary presence of intense X-ray and/or ultra-violet radiations
BACKGROUND AND OBJECTS OF THE INVENTION 
     It is broadly old to employ a spot of material (U.S. Pat. to Winter No. 3,597,054, 8-3-71) fluorescent to ultraviolet radiations to warn persons of the presence of dangerous intensities of such radiations. It is also known to utilize such materials in relatively complicated meters (McKee U.S. Pat. No. 3,194,963) and dosimeters (Jubb U.S. Pat. No. 3,710,115). But it is not known to provide a very simple device capable of being worn by a person to give a printed-message warning of the momentary presence of dangerous intensities of one, two or more ranges of such radiations. It is the principal object of this invention to provide such a device. Other objects and advantages will appear as the following description proceeds. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWING FIGURES 
     FIG. 1 is a plan view of a preferred embodiment of the invention. 
     FIG. 2 is vertically expanded elevational view in section taken on the line 2--2 of FIG. 1. 
     FIG. 3 is a plan view of a simplified form of the invention. 
     FIG. 4 is a vertically expanded elevational view in section taken on the line 4--4 of FIG. 3. 
    
    
     DETAILED DESCRIPTION 
     With reference now to FIGS. 1 and 2, the numeral 11 generally designates a card for warning persons of the momentary presence of dangerous intensities of both ultra-violet and X-ray radiations and also of the degrees of said intensities. The device 11 comprises a base lamina 13 of cardboard or plastic material onto which has been laid or coated a layer 15 of fluorescent material. The material of the layer 15 can be any substance (e.g. lead-barium sulfate or zinc-cadium sulfide) which glows either under X-rays or under ultra-violet radiations in the sunburn range. On the left half of the coat or layer 15 the message U-V is printed with an ink containing a substance inhibitory to ultra-violet rays (e.g. phenyl salicylate) so that when the layer 15 is U-V activated the message U-V will appear in dark lettering on a luminescent background. The ink containing the inhibitory substance will be of a color (e.g. yellow) closely matching that of the layer 15 so that the message will be substantially invisible under safe-radiations conditions. The legend &#34;ULTRA-VIOLET&#34; can either be similarly printed or be printed to show as dark lettering under all conditions. 
     The right half of the layer 15 is covered by a layer or coat 17 of a substance (e.g. phenyl salicylate) inhibitory (i.e. absorptive and/or reflective) to ultra-violet radiations so that the message X will be activated only by X-rays (which rays will also activate the U-V half of the fluorescent layer 15). 
     Each half of the layer 15 is desirably provided with steplayer-attenuation devices 19 of known constructions to indicate degrees of the radiations detected by the card 11. Each attenuation device 19 is formed by a plurality of stepped layers or coats 21, each containing materials partially inhibitory to the rays detected by its half of the card (e.g. phenyl salicylate for the U-V side and lead salts for the X side). Thus the blocked areas 1, 2,3,4 of each attenuation device 19 will be actuated serially as the intensity of its detected radiation increases: &#34;1&#34; for low, &#34;12&#34; or &#34;123&#34; for moderate and &#34;1234&#34; for high levels, respectively. 
     The base lamina 13 and its superposed elements 15-21 are encased between two waterproof and easily cleaned transparent plastic sheets 23, thermoplastically welded together or otherwise sealed along their margins 25. 
     The simpler form of the invention disclosed in FIGS. 3 and 4 has its elements designated by primed numerals corresponding to parts bearing unprimed numerals in FIGS. 1 and 2. The layers or coats 26 may be formed of or printed with X-ray inhibiting material so as to show always as dark messages on a lighter (e.g. yellow) background that glows and thus brightens under X-ray activation. A light-transparent layer or coating 27 containing an ultra-violet-inhibiting substance overlies the layers 26 so that the X-ray messages of the elements 26 will not respond to ultra-violet radiations. The middle or symbol message 26 can be printed with an ink containing an X-ray inhibiting pigment and other pigments making it colorwise match the fluorescent coat 15&#39;, so as thus to be substantially invisible in the absence of X-rays. 
     The ultra-violet (right) half of card 11&#39; has a layer or coating 15&#39; containing a material fluorescent to the selected U-V range to be monitored. As in FIGS. 1 and 2, the coating may have printed thereon the message AVOID SUNBURN with an ink containing a substance inhibitory to ultra-violet radiation and pigments selected to make the ink match the layer 15&#39;  in color (e.g. yellow). But as shown in FIG. 4, the message can alternatively be printed on a transparent sheet 28. A disc 29 can be added to serve as an attenuating device similar to devices 19 previously described. The disc 29 could be divided into halves or fourths (not shown) differently coated with U-V-inhibiting materials so as to indicate degrees of intensity of the delected U-V radiations monitored. 
     While the device has been shown in the form of a card, it should be noted it could have a cylindrical or spherical base lamina, if desired.