Housing with gradually varying thickness

Abstract

A plastic housing comprises a top wall, a plurality of sidewalls extending from the top wall, each sidewall having a first end adjoining the top wall and an opposite second end, the sidewalls cooperatively defining an opening at the second ends thereof; the top wall has a uniform thickness, and a thickness of each of the sidewalls gradually decreases from the first end to the second end. Because of the shrinkage rate of the second ends of the sidewalls is much greater than the first ends of the sidewalls, the thickness of each sidewall is decreasing from the first end to the second end, therefore, the shrinkage deformation of the sidewalls can be even with the gradient thickness. The warping of the sidewalls is alleviated or is avoided.

What is claimed is: 
     
         1 . A plastic housing comprises:
 a top wall; and   a plurality of sidewalls extending from the top wall, each sidewall having a first end adjoining the top wall and an opposite second end, the sidewalls cooperatively defining an opening at the second ends thereof;   wherein the top wall has a uniform thickness, and a thickness of each sidewall gradually decreases from the first end to the second end.   
     
     
         2 . The housing according to  claim 1 , wherein each sidewall has a maximum thickness at the first end thereof. 
     
     
         3 . The housing according to  claim 1 , wherein the top wall is rectangular, and the number of the sidewalls is four. 
     
     
         4 . A plastic housing comprises:
 a round top wall; and   
       a cylindrical sidewall extending from the top wall, the sidewall having a first end adjoining the top wall and an opposite second end, the side wall defining an opening at the second end thereof; wherein the top wall has a uniform thickness, and a thickness of the sidewall gradually decreases from the first end to the second end.