| 摘要 |
Provided is a balancer for a sash window, having a compact ratchet mechanism. Also provided is a sash window having an excellent function, such as the function of natural illumination, achieved using the balancer. The present invention is provided with: a shaft member (132); a spiral spring (150) which has one end affixed to the shaft member; a winding drum (140) which can be rotated by the shaft member and which has a helical groove formed in the outer peripheral surface thereof; and a ratchet mechanism (121, 133, 134) which can adjust the elastic force of the spiral spring. The ratchet mechanism has: a ratchet gear (133) which is provided to one end of the shaft member and has ratchet teeth (133a, 133a, ...) formed on the outer periphery thereof; and a gear engagement member (121) which has engagement sections (123, 124) provided so that the engagement sections (123, 124) can be engaged with and disengaged from the ratchet teeth and which is disposed along and parallel to the axis of the shaft member. |
