GB821719A - Improvements in or relating to magnetic compasses - Google Patents

Abstract

821,719. Magnetic compasses. GLAUSER, J. M. Dec. 3, 1957 [Dec. 17, 1956], No. 38445/56. Class 97(2) In a compass in which the magnetic unit is immersed in liquid in an inner container 20 having an aperture 23 communicating with an outer container 10 and located so that it is covered by the liquid in all positions of the compass, the magnetic assembly is carried on a pivot 27 slidably mounted in a sleeve 26 extending through the base of the inner container and held in place by a spring 37 which urges a stop on the pivot, such as the nut 35, into contact with the inner container. In the form shown the container 20 is located on a flange 22 projecting inwardly from the container 10 by the glass 12 secured by a rubber seal 14 and a ring 13. An outer glass 17 is also provided. The bottom of the housing 10 is closed by a flexible diaphragm 11 having at its centre a threaded bush 40 closed by a washer 38 and threaded cap 39, by removal of which the pivot 27 may be withdrawn. The outer container also carries a base plate 45, with central aperture 46 to which a rubber ring 47 is secured. A spare pivot 75 is stored in a housing 78. A sighting arm 60 is pivoted to the container 10 at 61. A magnifying prism 62 is pivoted at 65 to a member 67 carried on parallel rods 68 slidable relatively to the container but with a clamp 70 secured by a screw 71. The rods 68 are pivotally secured to a ring 72 for holding the compass.