GB606555A - Improvements in or connected with vibration damping mountings for optical observation instruments - Google Patents

Abstract

606,555. Mountings for optical apparatus. BARR & STROUD, Ltd., FRENCH, Sm J. W., STRANG, J. M., and MAcGILL, C. D. June 13, 1944, No. 11330. [Class 97 (i)] [Also in Group XXXII] A resilient mounting for optical observation instruments is provided with at least one damping device comprising a piston slidable in a cylinder open to the atmosphere at both ends, the clearance space between the piston and cylinder containing a viscous, non-volatile, non-freezing oil or other medium which provides a viscous drag. As shown in Fig. 2, the piston-rod D has universal ball connections 4, 5 with the piston C and supported structure E, respectively, which allow relative lateral movements between the supporting structure A and the structure E, the seating 6 for the ball connection 5 carrying a grease chamber 7 of screw-cap type connected by a passage 8 with a passage 9 in the rod D from which radial passages 10 lead outwards for lubrication of all the working parts. The piston C, which is lagged with hard felt, cork, or fabric material 3 impregnated with viscous grease, has a coefficient of expansion greater than that of the cylinder so that when the temperature rises the pressure on the lagging 3 increases and so compensates for the decrease in viscosity of the grease. Figs. 3, 4 show a further construction in which the cylinder B is divided vertically at 11 and cut horizontally at 12 to give it resilience. A stud 13 passing freely through a lug 15 on one part is screwed into a lug 14 on the other part of the cylinder against the action of a spring washer 16 so that, as the piston expands with increase of temperature, increased pressure is exerted on the cylinder, which yields in accordance with the regulation of the stud 13. Specifications 502,535 and 588,137 are referred to.