Lid and housing

A lid for a housing, said housing having wall means defining a cavity with an upper opening surrounded by an upper edge generally rectangular in shape, said lid comprising;

• a generally rectangular shaped lid member formed of plastic material, said lid member having an upper end and a lower end,
• a seating surface extending along the four sides of said lid member on said lower end and extending inward from the peripheral edges thereof adapted to rest on the upper edge of said housing to support said lid member in a position to close the upper opening of the housing,
• a primary ridge formed on the lower end of said lid member extending along its four sides at a position spaced inward from the peripheral edges thereof,
• said primary ridge comprising two straight portions respectively extending along two opposite sides of said lid member and two outwardly curved portions respectively located near the other two opposite sides of said lid member,
• said two straight portions and said two outwardly curved portions of said primary ridge extending below said seating surface a given distance,
• a secondary ridge formed at each corner of said lid member on its lower end and extending downward from said seating surface a distance which is less than said given distance,
• each secondary ridge being a curved member having two ends connected to the outer side of said outwardly curved portions of said primary ridge at each corner of said lid member and having an intermediate portion curving outwardly toward said corner,
• said secondary ridges being located inward from the peripherial edges of said corners and defining the inner boundry of said seating surface at said corners,
• said straight portions of said primary ridge defining the inner boundry of said seating surface on said two opposite sides of said lid member,
• said outwardly curved portions of said primary ridge between said secondary ridges defining the inner boundry of said seating surface on said other two opposite sides of said lid member.