| 摘要 |
335,057. Thornton Pickard Manufacturing Co., Ltd., Pickard, A. G., and Slinger, F. Sept. 19, 1929. Enlarging.-For focusing purposes, the lens carrier or part C is mounted on an extension frame D sliding on the base A on which the body of the apparatus is fixed. A focusing bar E extending through a clamp F on the stationary base A is connected to the front by a screw, so that after drawing out the front for approximate focus and clamping the bar E, the lens can be accurately focused by the screw adjustment. In the form shown, the front carries a rotatable screw threaded in the bar E. Alternative constructions are described for the screw adjustment. |
