Patent GB-191505608-A (GB)
Title: A New and Improved Instrument for Determining the Speed of Aircraft and the Proper Moment for Dropping Bombs therefrom.
Inventor: BREGEON EUGENE BREGEON TEMPLE
IPC: G01P3/36
Filed: 1915-04-14
Abstract: 5608. Temple, E. B., [formerly Bregeon, E.]. April 14. Sighting-devices for use in dropping projectiles from aerial vessels. Apparatus for indicating the speed of aeroplanes &c., and for determining the precise moment for releasing a bomb comprises two pivoted telescopes, one of which is reciprocated at such a rate that an object on the ground appears stationary, the other telescope being thereby adjusted so that the bomb is to be released when the target appears on the cross-wires. The reciprocating sighting telescope 1 is pivoted at 3, Fig. 1, on an upright arm 2 and is moved by a pin which engages a slot 7 and is carried by a slider 5 on a horizontal arm 4. The arm 2 is graduated for altitude and the arm 4 is capable of adjustment thereon. Movement of the slider 5 to reciprocate the sighting telescope is effected by the vertical movement of a slotted bar 9 which engages a pin 8 on the slider 5 coaxial with the first pin and is pivoted at 16 to a guide 10 moving on a rod 2' being supported at the other end by vertical guides 18 capable of adjustment on a horizontal rod 20. A clock driven helical cam 11 engaged by a projection 26 on the slider 10 serves to reciprocate the rod 9. After adjustment for altitude has been made, adjustment for variation of speed is effected by varying the inclination of the rod 9 through a worm 21 engaging the slide 19 carrying the guides 18, the shaft being geared to an indicating band. The telescope 27, Fig. 4, is pivoted coaxially with the sighting telescope and the slope must be such that it is directed to a spot which will be vertically under the aircraft after travelling for the period occupied by the body falling to earth. Variation in the slope of the telescope 27 is produced by moving an arm 28 vertically to adjust for alteration of time of descent due to variation of altitude and by moving a slider 29 horizontally to adjust for speed, the slider being provided with two pins engaged respectively by a slot in the telescope and by guides 32 adjusted separately or by the guides 18. Another device for reciprocating the speed telescope is shown in Fig. 8 wherein a travelling band 37 is driven by a variable speed clock 32, the slider 18 being secured to the band by clips which are manually released at the end of the travel and the telescope returned. Adjustment for variation in speed is effected by a cam 41 carried by the manually adjusted slide 19<b>, the cam serving to alter the drive of the clock through an arm 42. Simultaneous vertical adjustment of the arms 4 and 28 is effected by means of a cone 65, Fig. 10, which is arranged so that the length of a cord wound therefrom corresponds to the distance fallen by a body from the greatest height for which the instrument is designed. In the form shown in Fig. 10, a cord 55 is connected to the arm 4 and passes round a drum 56 which is connected by gearing to a second drum 59 having secured thereto a cord 52 wound on the cone 65. The cone is mounted on a screwed shaft 63 moving in a nut 64 so that the cord is always vertical. Movement of the arm 4 rotates the shaft 63 and this through a cord 60 wound thereon adjusts the position of the arm 28.