GB390728A - Improvements in mountings for rangefinders on unstable supports such as ships - Google Patents

Abstract

390,728. Rangefinders. NAAMLOOZE VENNOOTSCHAP NEDERLANDSCHE INSTRUMENTEN COMPAGNIE NEDINSCO, 9, Molensingel, Venlo, Holland. Sept. 17, 1932, No. 25887. Convention date, Sept. 25, 1931. [Class 97 (i).] Means for maintaining the plane of triangulation of a rangefinder at a fixed inclination to the horizontal plane when the rangefinder is mounted on an unstable platform such as a ship, comprises a gimbal-mounted body maintained in a fixed direction in space by stabilizing means, and means for coupling the said body to the rangefinder in such a way that any oscillation of the ship in a vertical plane at right-angles to the plane of triangulation imparts to the rangefinder rotation about its horizontal axis through an angle which, for any position of the plane of triangulation, is equal to the angle of oscillation of the ship in the said vertical plane relatively to the stabilized body. In the form shown in Figs. 1 and 2, the rangefinder 6 is mounted in a bush 4 so as to be rotatable about the horizontal axis Y-Y and the bush 4 forms part of a member 5 which is mounted so as to be rotatable about the vertical axis X-X on a support 1 fixed to the ship. A member 10 is suspended from the support 1 by pivots 7, 9 and a cardan ring 8, so as to be universally movable, and is stabilized by means such as a pendulum 11. A vertical shaft 12 in the member 5 carries at its lower end a bevel wheel 13 gearing with a bevel wheel 14 mounted in a bracket carried by the member 5 and having extensions 15 passing round a member 17 rotatably mounted in the member 10. A pivot pin 16 passes through the members 15, 17, the axis of this pin containing the centre of the cardan suspension of the member 10. Rotation of the shaft 12 is transmitted by bevel gears 19 to one member 20 of a differential gear, the member 21 of which can be rotated by a handwheel 27. The intermediate member 23 is connected to a pinion 28 gearing with a pinion 29 fixed on the range-finder. Oscillation of the ship about a horizontal axis parallel to Y-Y causes the wheel 13 to be rotated by rolling over the wheel 14, the consequent rotation of the wheel 28 causing the rangefinder to be turned about the axis Y-Y through an angle equal to the angle of oscillation of the ship. Oscillation about the axis X-X or about the horizontal axis at right-angles to Y-Y does not produce any rotation of the wheel 13. The rangefinder can be turned by hand about the axis Y-Y by the wheel 27 to vary the inclination of the plane of triangulation. In another form, Fig. 3, the stabilized body 10 is connected by a vertically-guided pin 30 to a lug 32 on a sleeve 33 loosely surrounding the rangefinder, this sleeve having a flange 37 carrying a worm 38 gearing with a worm-wheel 39 fixed on the rangefinder and capable of being rotated by a hand-wheel 40. Another form is described in which the rangefinder and the stabilized body are mounted in a turret which can be rotated about a vertical axis.