GB819523A - Improvements in or relating to periscopes - Google Patents

Abstract

819,523. Periscopes. ELECTRIC & MUSICAL INDUSTRIES Ltd. Feb. 14, 1956 [Feb. 19, 1955], No. 5035/55. Class 97(1) A periscope comprises a housing containing a focusing lens system and having a hollow member forming a lateral passage for entry of light in to the housing, means being provided whereby a cooling fluid can flow through the housing and out through the lateral passage. The periscope shown in Fig. 2 may be projected into the combustion chamber of a boiler of the kind described in Specification 732,926 [Group XII] and comprises a tube 2, 3 with telescopic tubes 29, 28 and 29a carrying levers 36, 37 supported therewithin by annular members 11, 20 and 21, having angularly spaced outer apertures. A hollow member 9 supports an objective 35, the incident light through which is reflected by an adjustable mirror 30 through lenses 36, 37 to form an image as a screen e.g. on the pick-up tube of a television camera mounted in a cradle 17 attached to the periscope. A conduit 50, 51 supported by aligned apertures in members 11, 20 and 21 passes cooling fluid from an inlet 48 to an outlet 49 above objective 35 and coating fluid is also circulated through the annular passage surrounding telescopic tubes 29, 28 and 29a from inlet 44 to an outlet 46. In the form shown in Fig. 4, the hollow member forming the light entry passage comprises telescopic tubes 60, 61 respectively carrying negative lens 62 and positive lens 64, lens 62 being partitioned by a window 68 as of heat resistant glass. Fluid discharge openings are provided in the tubes 60 and in the mounts supporting lens 62 and window 68 in the tube 60. A rod 73 for adjusting reflector 30, against the action of a spring 74, extends to the liquid outlet of the periscope.