GB1098208A - Sighting apparatus - Google Patents

Abstract

1,098,208. Levels. VISOMAT A. G. Sept.8, 1966, No.40178/66. Heading G1F. A sighting or dumpy level comprises a telescope 5 pivoted on a bearing body 1 for rotation about a horizontal axis 4, the telescope being carried by a bracket 12, which is also pivotable about the axis 4 over a range exceeding 180‹ e.g. 240‹, and which may be held at selected angular positions by means of a ratchet device (not shown), a stop 11 locating the telescope 5 with respect to the supporting bracket 12. This arrangement enables back sighting to be carried out without the need for rotation of the telescope through 180‹ in azimuth. A spirit level 8 and associated mirror 9 are provided for levelling the telescope 5 and a further level 13 and mirror 14 for levelling the axis 4. The bearing body 1 is adjustable in azimuth around a supporting tube 15, and is lockable in its adjusted position by use of a knurled collar 22. Fine height adjustment of the bearing body 1 is effected by rotating a knurled knob 20 on a rod 16 having opposite hand screw threads at its two ends, the upper end engaging in a bush 19 fixed to the body 1. A hook 21 for a plumb-bob is also provided. Azimuth readings for the telescope may be made by use of a magnifying glass 23 co-operating with a divided circle on a projection of the collar 22.