Window shade casing

A window shade casing for a window, the latter being above a horizontal leg of an upper window frame, comprising

• a casing including an outer wall, a cover wall, a side wall, and a casing bottom respectively releasably connected to one another,
• said cover wall and said side wall comprise identical angular shaped members,
• said side wall and said cover wall have edges engaging on the casing and hooking in one another,
• each said angular shaped members has a longer angle leg and a shorter angle leg, each of said longer angle legs is formed with a connection catch hook at a free end thereof,
• each of said longer angle legs is formed with recesses on an inner wall side thereof, said recesses are disposed spaced apart one after the other in the form of a row, said recesses at least in part have the profile of said connection catch hook and form nominal separation positions adapted for shortening of the longer angle leg leaving a catch hook at a free end of the latter,
• said catch hook has a triangularly shaped cross-section and is formed tapering toward the free edge,
• said shorter angle leg has an inner groove wall and an outer groove wall spaced therefrom forming an engagement groove therebetween, said outer groove wall is shorter than said inner groove wall,
• said inner groove wall is formed on a free end thereof with a shoulder, said shoulder engages in back of one of said catch hooks in an assembled position of said walls.