Counterbalanced drop-down door for dish-washer

摘要

Brackets (4) on the door-frame sides (3) carry pivot pins (7) supporting cam-plates (6) fixed to the door (5,2). Pegs (14) in quadrant slots (8) in the plates act as end-stops. A steel band (9) runs from a notch (18) in each cam-plate along a plastic channel on the edge (60) and under a fixed friction shoe (15) to the balance spring (10). The band tension (Fr), adjustable at the spring support (11), produces, in the open position, a moment (Fr.d) about the pivot, balancing that of the door weight (Fg.L).As the door rises, the tension reduces, as does the moment due to the door weight. The cam profile, taking account of these changes, keeps the door in stable equilibrium, or nearly so, at all angles.