GB473000A - Improvements in sights for aerial bombing - Google Patents

Abstract

473,000. Bomb - dropping sights. SOC. ANON. DE CONSTRUCTIONS AERONAUTIQUES S.A.C.A. April 3, 1936, Nos. 9948 and 9949. Convention dates, April 5, 1935 and May 18, 1935. [Class 92 (ii)] [Also in Groups XIX and XX] Relates to sighting devices for nose - dive aerial bombing of the kind in which the true vertical over the target is obtained by apparatus employing a gyroscope G<1>, Fig. 1, an optical system such as C<1>, and parallel reflecting surfaces such as A<1>. According to the invention, a mirror M<1>, fixed to the casing of the rotor of a vertical-axis gyroscope, receives directly or by reflection the image of a mark such as S<1> which appears to be on the ground below the observer O who simultaneously sees the target and controls the aeroplane to keep the target and the mark in coincidence. In the form shown in Fig. 1, a luminous mark S<1> is by a lens C<1> brought to a focus at the centre 1<1> of the gyroscope which is also the focus of the curved mirror M<1>. It follows that, for inclined positions of the lens and the transparent reflecting surfaces A<1> carried by the aircraft, the rays sent back by the gyroscope are always vertical. These rays reflected by the surfaces A<1> are received by the observer superposed on his direct view ofthetarget. In a modification, Fig. 3, the target P<2> is seen directly through a right-angled prism system R<2> and its reflection, by means of the system R<2>, a prism R<1> and a flat mirror M<2> on the gyroscope, is seen in the true vertical. In a further modification, a flat mirror on the gyroscope is used with the arrangement shown in Fig. 1, a second lens system with two-to-one magnification being interposed between the transparent reflecting surface A<1> and the gyroscope. By this means, the rays reflected by the flat mirror are turned into a true vertical line. By a slight adjustment of the two-to-one lens system, a deviation from the true vertical to correct for the action of the wind on the bomb can be provided for. The invention is particularly suitable for viewing the target when speed measuring during horizontal flight, since the view of the target is undisturbed by instability of the aircraft. For this purpose, the luminous mark is surrounded by a luminous measuring circle or the mark is replaced by equidistant luminous spots which are displaced at a measured rate until they appear stationary on the ground. The Specification as open to inspection under Sect. 91 also describes with reference to Fig. 2 (Cancelled) a conical sighting tube P pendulously supported within a second conical airscreened tube V carried by the aircraft. Motion of the tube P about the axes of the gimbal joint C is damped by dashpots D. This subjectmatter does not appear in the Specification as accepted.