Patent GB-649048-A (GB)
Title: Improvements in or relating to phonograph apparatus made particularly for telemetering purposes
IPC: G01W1/00
Filed: 1948-02-27
Abstract: 649,048. Gramophone records; reproducing sound; electric selective signalling system. DEPARTMENT OF COMMERCE, DIRECTOR OF THE OFFICE OF TECHNICAL SERVICES OF. Feb. 27, 1948, No. 5939. Convention date, Oct. 17, 1944. [Classes 40 (i) and 40 (ii)] A phonograph combination includes a record bearing an intelligence signal on only a raised sector or sectors of the record and a co-operating reproducing arm. As applied to a radiosonde, Fig. 11, three pick-up arms 1112, 1114, 1116, responsive to pressure, temperature, and humidity respectively, are mounted in a box 1100. A record 1125 is mounted for rotation on a spindle 1106 actuated by an anemometer 1108 or by a small synchronous motor. The record comprises a disc 302, Fig. 3, with a raised sector 200 on concentric grooves of which is recorded the intelligence signal. The pick-up arms are arranged to engage only the raised sector of the record and so that only one is in engagement with the sector at a time, the pick-ups being free to be positioned according to the prevailing conditions when out of engagement with the raised sector. The pickup arms convey the intelligence particular to a groove to a transmitter for reception at a distant station. The radiosonde may be dropped by parachute (Fig. 12, not shown). Record construction. The record is provided with one or two raised sectors carrying the intelligence signals, e.g. Morse signals, in concentric grooves. The grooves may extend over the whole of the record, Fig. 4, and the raised sector or sectors 400 may have curved leading and trailing edges 404, 406 to avoid any side sweeping forces on the pick-up arm. Reproducing arm construction. For use with " hill and dale " recordings the pick-up may comprise a spring conductor 720, Fig. 7,. terminating in a block 708 which runs along the surface of the record. A needle 714 is fastened on a conductive lever 712 insulated from the conductor 720 by a bracket 710. A small tension spring 724 biasses the needle towards the record, so that as the needle passes over the record contact is made or broken between a contact 722, on the arm 720, and the lever 712, the electrical impulses 'derived serving to key the transmitter. In a modification electric contact may be made while the needle is traversing to " dale " instead of whilst traversing a " hill " (Fig. 9, not shown) and in a further embodiment a conductive needle, co-operating with a record having grooves in which the signal is in the form of conductive and non-conductive strips may be used (Fig. 10, not shown). In a further embodiment a snapaction switch is utilized to control the making and breaking of electric contacts. The switch consists of a box 800, Fig. 8, attached to a spring strip 801 so that the box 800 runs along the surface of the record. The needle 815 is mounted on a conductive T-shaped spring 809 secured at 824 and normally biassed downwardly by portions 812, 813, the ends of which are journalled in V-shaped grooves 814 in a U-shaped block 808. In this position contact 826 on the spring 809 engages a contact-plate 820. When the needle is biassed upwardly by the recording the contact 826 engages a second contact-plate 822. Specification 649,049 is referred to.