摘要 |
Improvements in a treatment chair whose backrest frame is designed to be tiltable with respect to the seat frame of the chair by use of a roller rotating within a guide groove are disclosed. In the disclosed embodiments all utilize an arc segment portion groove. As a result, the top portion of the backrest frame holds substantially the same peripheral speed throughout travels with raising and lowering of the backrest frame and the patient resting against the backrest frame is thereby free from any uncomfortable feeling due to preceptible changes in peripheral speed during the rise and fall movement of the frame. |