| 摘要 |
504,791. Lamp &c. stands. HINDER, P. G. H. Oct. 28, 1937, No. 29479. [Class 52 (iii)] An adjustable stand for a lamp or the like comprises a base member 10, an arm 12 adapted to pivot about a fixed axis in the base member, a lever 18 pivoted to the arm at a point 20 intermediate the ends of the lever, a spring member 34 between one end of the lever and the arm, a further lever 23 pivoted on the. other end of the lever 18, and a further spring member 34 arranged between the levers 23 and 18. The arm 12 comprises spaced metal strips fixed to a block 15 pivoted on a vertical screw 16 entering the base 10 and carries at its upper end a cylinder 17 in the end faces of which are cut slots to receive spaced metal strips constituting the lever 18. The second lever 23 comprises a tube carrying the lamp 29 by. a universal joint 30 and is pivoted at 25 between the strips of the lever 18. Bolts with milled nuts 22, 26 provide variable friction at the pivots. The springs are arranged between a point 35 on the arm 12 and the end of the lever 18, and between a point 36 on the lever 18 and the end of the lever 23 respectively, and each comprises a hollow cylinder 34 pivoted at 35 or 36 and containing a compression spring arranged to be compressed by a member 38 attached to a tube 39 which projects through the end of the cylinder and carries a block 40 pivoted to the end of the lever 18 or 23 by screws 41. The compression of the springs is adjustable by nuts 43 on the threaded lower parts of the tubes 39. The flexible conductors 44 pass through the tubes 39, 23 to the lamp. |
