A portable roll up window blind removably mountable in
- a window frame comprising,
- a shell housing having a generally inverted U-shaped cross section and including at least two shell sections slidably engaged with one another and adjustable for setting said shell housing to a selected length,
- a locking means mounted on one of said shell sections and operative for maintaining said shell housing at said selected length,
- a first end plate mounted within a first free end of said shell housing, said first end plate being movable slidably relative to said first free end of said shell housing,
- a second end plate fixedly mounted at a second free end of said shell housing and being located opposite to said first free end of said shell housing,
- a wedging means mounted on one of said shell section and operative for moving said first end plate slidably relative to said first free end of said shell housing for pressing said first end plate against a side wall of said window frame thereby said first end plate and said second end plate cooperate with one another for pressing tightly against opposite side walls of said window frame for maintaining said shell housing securely and removably mounted at a selected height level inside said window frame,
- a round support pin mounted at a center position on an inner surface of said first end plate,
- a winding means mounted at a center position on an inner surface of said second end plate, said winding means having a rotary shaft extending in a cantilever manner and located directly opposite to said round support pin, said rotary shaft having a free end portion having a multi-sided cross sectional shape, said winding means having a pull chain operative for rotating said rotary shaft,
- a telescoping winding core including a first elongated core section and a second elongated core section slidably engaged with one another and being adjustable for setting said winding core to a selected length for locating between said first end plate and said second end plate within said shell housing, and said first core section having a hollow end portion having cross sectional shape and dimensions equal to said multi-sided cross sectional shape and dimensions of said free end portion of said rotary shaft, said second core section having a hollow end portion rotatably engaged with said round support pin,
- a first elongated slot formed in one longitudinal side wall of said first core section, and a second elongated slot formed in one longitudinal side wall of said second core section, said first elongated slot and said second elongated slot being aligned with one another,
- a first window blind panel having a top edge attached to a longitudinal external surface of said second core section,
- a second window blind panel having a top edge attached to a longitudinal external surface of said first core section and a vertical edge portion of said second window blind panel being extensible within said second elongated slot of said second core section.