Improvements in or relating to tripod stands for cameras, theodolites and other instruments

摘要

701,937. Tripods. NATIONAL RESEARCH DEVELOPMENT CORPORATION. June 20, 1952 [June 27, 1951], No. 15303/51. Class 52(3) A tripod stand has three adjustable ties which extend inwardly from the three tripod legs 11 and are pivotally connected to an annular member 28, and a universally mounted platform 20 from which extends a rigid stem 26 with which the inner members of the ties co-operate for setting and holding the platform angularly in relation to the vertical. The tripod legs are pivotally attached to a head 13 mounted on gimble rings 15, 17 the ring 17 carrying a housing 18 for a thrust bearing 19 carrying the platform 20. Also secured to the inner ring 17 is a tubular extension 21 to which is attached the lower disc 22 of two annular friction discs between which is a third disc 23 rotated by the platform 20. The upper disc 42 is constrained for rotational movement with the extension 21 but can slide axially to enable the braking effect to be altered by a hand screw 45. The telescopic ties comprise a solid rod 29 connected to the leg 11 by a pivot 30 and a tubular member 31 connected to the annular member 28 by a pivot 32. Diametrically opposite each tie is a roller 33 held in position by a screw 34 mounted in a threaded member 35 pivoted to the annular member 28 so the stem may be locked in its adjusted position. A thumb screw 36 holds the telescopic stay in its desired position.