GB558685A - Improvements in or relating to course and speed calculating apparatus for use with aeroplanes - Google Patents

Abstract

558,685. Course-recording apparatus. ARON ELECTRICITY METER, Ltd., and RIORDAN, E. J. July 13, 1942, No. 9705. [Class 97 (ii)] In course-recording apparatus in which one side of a triangle is set to represent the wind speed and direction, a second side the air speed and direction of an aeroplane and the remaining third side giving the ground speed and direction the said third side is constructed as a flexible tape or cord which may be graduated to give direct readings. As shown in order to set the apparatus for wind and air speeds and directions ring discs 2, 3, 5, 7 are mounted concentrically the ring 2 being fixed to the base plate and the ring 7 mounted on a shaft 9. The rings are graduated as shown and are normally clutched together but may be declutched and rotated by pressing and rotating the winding knob 17, 18 or 19. The shaft 9 carries a crown wheel 10, Figs. 3, 4, operating a screw spindle 12 carried in a fork 13 having a hollow shaft 14 connected to ring 5. The spindle 12 has thereon a nut 21 to which is connected one end of the flexible tape 24 the other end of which passes over a pulley 34, Fig. 3, and is connected to a spring drum 30 mounted on a spindle 38. A second screwed spindle 26 is provided which is rotated by bevel wheels 33 and a hand wheel to operate a nut 28 having a pair of rollers or pins 29 between which the tape 24 passes and the spindle 26 is operated so that the distance of the nut 26 from the shaft 9 represents the air speed of the plane. In operation the ring 7 is declutched and rotated by knob 9 so that the datum mark 8 indicates the wind speed in miles per hour on the scale. Releasing the knob 19 immediately causes the rings 5, 7 to be in clutch again. Knob 18 is operated to declutch ring 5 from ring 3 and rotate the rings 5, 7 until the datum mark 6 indicates the direction of the wind. Finally ring 3 is declutched from ring 2 and operated by knob 17 until datum mark 4 indicates the heading of the aeroplane. The tape 24 will then be displaced for example, as shown at c the ground speed being directly read off the tape as it emerges from the rollers 29 and the drift angle will be shown by finger 36 which is operated by the angularity of the tape 24 canting a frame 37 pivoted to the nut 28. The spring drum 30 and spindle may operate an indicator 40, Fig. 1, to show the component of the wind speed which affects the ground speed.