GB561265A - Improvements in and relating to interval meters - Google Patents

Abstract

561,265. Echo-sounding. HUGHES & SON, Ltd., H. (Blaisdell, W. E. C.). Sept. 5, 1942, No. 12556. [Class 118 (ii)] [Also in Groups XVIII and XIX] An interval meter comprises a stationary reference point, a scale marked with indicia moving at a known velocity past said reference point, a reference point on 'the scale that coincides with the stationary point at the beginning of the time interval being measured, and a light source flashed stroboscopically at the end of the time interval so as to illuminate the stationary point and that part of the scale and the indicia in proximity therewith. In echo-sounding apparatus, a disc 13, having two concentric translucent scales 14, 15 is rotated by a shaft 6 carrying a fibre ring 51 and a metal segment 52 which closes a circuit as the disc passes zero position to cause a transmitter 31 to send a signal to the ocean-bed. The reflection is picked up by a receiver 32 and passed to an amplifier 36 which flashes a lamp 23 for a very short time. The successive flashing of the lamp has a stroboscopic effect so that the appropriate number on the scale is illuminated and appears to be stationary. Operation of a knob 22 positions a shutter 16 to reveal only one scale, and at the same time moves changespeed gears 7, 8 whereby the disc can be driven at either of two speeds according to the scale used. The reading on the scale may be viewed through a magnifying glass 25. Adjustment of zero. Adjustment for the draft of the vessel or other factor may be made by rotating a knob 50 to position a sector 46 carrying a contact member, 45 relative to the metal segment 52. The transmitter 31 may be controlled in a modification by a photo-electric cell energized by light passing through an aperture in the disc 13 when it passes the zero position. In a further modification, the disc 13 is replaced by a drum, Fig. 5 (not shown) with the scales side by side, one being exposed at a time. Recording apparatus. In yet another modification, Fig. 6, two discs 63, 64 are mounted on opposite sides of the light, and photographic film is drawn from a spool 71 and exposed in front of a window 69. The film is developed between rollers 74 and 75 before passing out of the apparatus.