Thermally movable plastic devices

Abstract

In accordance with the invention, thin bodies of plastic, such as sheets or strands, with substantially different thermal coefficients of expansion are laminated together to make plastic bodies which move in response to heat. The movable plastic bodies can be secured to a suitable base to make a variety of devices for amusement, temperature monitoring and display. Applications for amusement include a thermally blooming flower, a solar activated butterfly, and curling hair for a doll. Applications for temperature monitoring include safety lids for drinking cups, sunlight blockers including Venetian blinds, and ventilators.

1 . A Venetian blind comprising a plurality of blades suspended from a head rail, the head rail having means for mounting to a frame opening; each of the blades contacting a thermally movable bilayer louver; the bilayer louver including at least a first and a second polymeric component, wherein said components have coefficients of thermal expansion differing by more than 1×10 −5 , and wherein movement of the bilayer louver varies the amount of light transmitted through the Venetian blind.  
   
   
       2 . The Venetian blind of  claim 1 , wherein the opening of said frame is covered by a transparent covering selected from the group consisting of a window, a door and a skylight.  
   
   
       3 . The Venetian blind of  claim 1 , wherein the movement of the bilayer louver indicates a bright light condition.  
   
   
       4 . The Venetian blind of  claim 1 , wherein the movement of the bilayer louver indicates a low light condition.  
   
   
       5 . The Venetian blind of  claim 1 , wherein the polymeric components are between about 1 and 10 mils in thickness.  
   
   
       6 . The Venetian blind of  claim 1 , wherein the first polymeric component is polyethylene and the second polymeric component is polyvinyl chloride.  
   
   
       7 . The Venetian blind of  claim 1 , wherein the first polymeric component is polyethylene and the second polymeric component is polypropylene.  
   
   
       8 . The Venetian blind of  claim 1 , wherein the first polymeric component is low molecular weight polyethylene and the second polymeric component is high molecular weight polyethylene.