GB191115283A - Improvements in and relating to Sighting Apparatus for Ordnance. - Google Patents

Abstract

15,283. Tsukalas, P. June 30. Range-keepers, -Relates to sights for targets moving in the line of fire, and consists in a device for keeping the sight automatically directed on the target. In the example shown, the sighting - telescope D is carried by a sight-bar E, sliding in a guide c<1> on an arm C attached to the gun cradle B, and may be adjusted by a milled head f<1> through a rack and pinion F, e<1>. A drum G having a cam surface g<1>, turns on a shaft H in the arm C and is driven through an easily disconnectible jaw clutch g<2>, by a clockwork or other motor in a casing c<4>, preferably at a uniform rate of about one revolution in twelve minutes. The operative part of the cam surface, which lies outside the angular space uyz, has a circular cross-section g<3> at its middle, while parallel sections are Archimedean spirals g<6>, approaching the axis H on one side of the section g<3> and receding from it on the other, and suited, for any given speed of the drum G, to various speeds of the target. As the cam surface g<1> rotates, it raises or lowers at a uniform rate an arm P, which may be caused to co-operate with any desired curve on the cam surface by rotating the set-screw N mounted in the lateral projection k<1> of the sleeve K, which may be clamped to the sliding bar E by the screw M. The range indicated by the mark c<2> on the scale e<2> is checked at intervals by a range-finder, and any error is corrected by an adjustment of the arm P along the cam surface. The clutch g<2> can be readily thrown out, and the drum G reset, when the inoperative part uyz of the cam surface g approaches the arm P. Specification 13,651/95 is referred to.