GB291023A - Improvements in devices for ascertaining the angular velocity of a shaft, coupled to a sighting device - Google Patents

Abstract

291,023. Naamlooze Vennootschap Nederlandsche Instrumenten - Cie. May 24, 1927, [Convention date]. Telescopic observations for measuring speed.- A device for ascertaining the angular velocity of a shaft which is coupled to a sighting device for pursuing a movable target is provided with an arrangement for recording the angular velocity in respect to time. The telescope 1 is rotated in azimuth to keep bearing on the target by means of a handwheel 2, gear 3, and worm 5, the shaft 4 of which is connected to a tacheometer 6, which moves the indicating needle of a speedometer 7 and a guided rod 10 proportionally to the angular velocity of the shaft 4. The shaft 10 moves at right-angles to a travelling strip 13 and carries a pencil 22 bearing on the underside of the strip, which is driven from a clock 17 and is ruled with lines 21 at equal intervals. The pencil traces a velocity-time curve on the strip. A rod 46 having a central transparent portion on which is ruled a line 49 is pivoted to a nut 24 at one end and is slotted at the other end to engage a pivot 48 on a nut 23. The nut 24 is moved by a handwheel 29 and screw 27, which also drives through bevels 30 a shaft 31 and bevels 32, 33, of which the wheel 33 is, together with a wheel 35 on a body 34, rotatably supported on the spindle 25. The shaft 25 is curved at the end 37 and supports a planet wheel 36 gearing with wheels 34, 38, which latter wheel is in one with a wheel 40 gearing with a wheel 41 on a screw operating a guided nut 43 having an index 50 moving over a scale 51. The screw is fitted with a handwheel 44. By adjusting the handwheels 29, 44, the rod or rule 46 may be inclined so that the line 49 lies along the general direction of the curve at an angle " a," the tangent of which represents the acceleration, and as the distance between screws 25, 27 is constant, the distance apart of the nuts at right-angles to this dimension, and consequently the movement of the index 50, is proportional to the acceleration and is indicated on the scale 51.