BALANCER DEVICE AND DOUBLE-HUNG SASH USING THE SAME

PROBLEM TO BE SOLVED: To provide a balancer device which can hold a double-hung sash at an optional position by generating torque by a spiral rod and a torsion spring for lightening an initial operating force when the sash is moved from a closed position to an open position. SOLUTION: A case 6 of the balancer device 4 is fixed to a window frame 1, and the spiral rod 9 arranged in the case is connected to the double-hung sash 2. When the sash is moved from the open position to the closed position, the spiral rod is pulled out from the case, and when the sash is moved from the closed position to the open position, it is withdrawn into the case. The lead lengths of respective twisted portions 11 of the spiral rod 9 in the direction from a drawing starting point to a drawing terminal point are set such that the lead lengths in a proximal zone are shorter than those in a drawing intermediate zone, that the lead lengths become longer as the spiral rod is drawn, and that the lead lengths in a distal zone are shorter than the longest lead length in the drawing intermediate zone. COPYRIGHT: (C)2010,JPO&INPIT