Open top hopper window and frame

An open top hopper window consisting of a hopper window (1) and a frame (2), wherein the frame has a top edge (22), a bottom edge (23), a left side (16) and a right side (17);

• wherein the inner part of the left and right sides of the frame (16 and 17) have a guide groove (4) located at the bottom edge, with a hole in the frame (14) located above such guide groove (4), wherein the joining between the hopper window (1) and the frame (2) is achieved through two bolts (18) located on outer bottom edges of the hopper window sliding into guide grooves (4) and through two arms (3) linking the holes in the frame (14) with two holes (21) in the hopper window (1) wherein the two holes (21) are located on the 35%-40% range of the total length of the hopper window (1) on the outer sides of the hopper window (1) always achieving an equilibrium position which allows positioning the hopper window at different opening angles and positions without effort when sliding and moving it.