| 摘要 |
768,473. Back-rest adjustments. EINAR RUSTAD. Feb. 23, 1955 [Feb. 24, 1954], No. 5463/55. Class 52 (2). A tubular support 4 for a back-rest is slidably mounted in a clamping sleeve 5 pivoted on a bolt 2 between side cheeks la beneath a stool seat 1. A clamping bolt 6 carried by lugs 5d on the sleeve moves in arcuate slots 3 in the side cheeks and a spring 11 biases the back-rest toward the vertical position when the clamp is released. |
