Patent GB-649049-A (GB)
Title: Telemetric system for meterological data
IPC: G01W1/00
Filed: 1948-02-27
Abstract: 649,049. Gramophone records; reproducing sound. DEPARTMENT OF COMMERCE, DIRECTOR OF THE OFFICE OF TECHNICAL SERVICES OF. Feb. 27, 1948, No. 5997. Convention date, June 25, 1943. [Classes 40 (i) and 40 (ii)] [Also in Groups XX and XXIX] In a telemetric system for the secret transmission of meteorological information to a distant station, elements sensitive to a plurality of conditions traverse associated pick-up arms radially over the surface of a revolving transcription record having a plurality of continuous concentric grooves in each of which is recorded a characteristic train of code signals. The record is-cyclically raised to contact the pick-up heads, which track particular coded grooves corresponding to the deviations produced by the respective sensitive elements, and is then lowered to allow the pick-up arms to be positionally readjusted in accordance with the meteorological conditions. The pick-ups comprise means for producing coded signal trains in an electric circuit to which they are sequentially connected, corresponding to the grooves tracked by the individual pick-up heads, and hence to the deviations of the heads by their associated measuring elements. The resultant signals key or modulate a radio transmitter, or transmit line signals, which are decoded at a distant station to indicate the meteorological conditions prevailing at the transmitter. In Fig. 1 a chassis 1 carries a turntable 5, driven by a motor M through a shaft 204, on which is a record 7 (Fig. 3, not shown) having separate continuous concentric grooves in each of which is recorded a continuous train of distinctive code signals in the form of hill-and-dale coded projections or lateral cut code-modulated audio signals (Fig. 7, not shown). The projections may be moulded into the record (Fig. 4) or consist of metallic inserts (Figs. 5, 6). Spaced about the turntable are six meteorologicallysensitive units A, B, C, D, E, F, which are mechanically linked to deflect their respective pick-up arms 31, 11, 39, 45, 101, 145 about filamentary suspensions carried by brackets fixed to the chassis. The arms carry pick-up heads having needles engageable in the record grooves to operate vibratile make-and-break contacts in accordance with the record modulations, and are traversible across the record surface in accordance with the deflections produced by the meteorologically sensitive units. Unit A comprises a train of aneroid cells 29 sensitive to barometric pressure and linked to arm 31 through wire 33; B comprises a thermometric fluid filled shell 36 flexibly connected to a pressure capsule 21 linked to arm 11 through band 19; C comprises a hair hygrometer 37 linked to arm 39 by rod 41; D comprises a sunshine-responsive element 43 deflecting arm 45, while E and F are wind velocity and direction units deflecting arms 101, 145 in correspondence with a wind vane assembly. The latter (Fig. 8) comprises a vane 47 with a horizontal tubular extension member 49 carried by the vertical casing 57 which is rotatable on a fixed hollow casing 53. A spindle passes through 51, 53, is rigidly connected to 49, and is connected by a flexible shaft 65 to transmit the vane orientation to unit F. Tubular member 49 carries a wind pressure tube 69 communicating through internal conduits and mercury pivot seals 75, 85, to the side tube 55 which is connected through a hose to an expansion bellows 99 linked through motion multiplying elements 119, 121, 123 to deflect the arm 101 of unit E. Wind direction unit F embodies a lost-motion device to prevent damage due to sudden gusts. Fig. 11 shows the mounting of arm 101 which is suspended from a bracket 185 concentrically with the pivots 157 of a U- bracket 155 carrying arms 159 and 161, the latter having an adjustable set-screw 189 bearing on the pick-up arm 145 and bent at its end 162 to pass through an aperture in the arm and abut on the periphery of the cam 187 rotated by the flexible shaft in correspondence with the orientation of the wind vane. Arm 159 has a bifurcated end engaging with lostmotion a rod 165 carried by the spring-loaded armature 151, of a solenoid 149, whose protrusion is limited by the angle-iron 175. On de-energization of the solenoid, the end of arm 161 is removed from the cam profile, and set-screw 189 from the pick-up arm surface so that the latter is free and the cam is allowed to rotate in correspondence with the wind vane. On energization of the solenoid, arm 161 moves anti-clockwise until its end abuts on the cam profile and the set-screw deflects the pick-up arm by an amount dependent on the cam position set by the instantaneous orientation of the wind vane. The turn-table spindle (Fig. 12) runs in a fixed housing 193 surrounded by a coaxial wheel 197, driven at reduced speed from the turn-table motor by a worm 201, which carries a cylindrical cam 203 having a flange 205 bearing a cam surfaced stub 221. A cylindrical follower 209 operated by cam 203 has a recess 211 and slides axially over the housing 203 while its rotation is prevented by key 213. This follower carries a thrust race 217 supporting the base-plate of the turn-table so that the latter is lifted to cause the record to engage the pick-up needles while the cam rides along the lower edge of the follower, and is lowered to disengage the pick-ups when the cam enters the recess. The turntable spindle assembly is surrounded by a distributer switch (Fig. 12) comprising a fixed insulating ring 225 spacedly carrying a two-way switch 240 and conducting sectors 227, 229, 231, 233, 235, 237, 239, one for each of the units A to F and one spare, which form the upper plates of make-and-break switches having identical lower plates. The switch contacts are adjustable by screws 253, 255, 257, 259, 261, 263, 265. The stub 221 rotating with the flange of the cam 203 selectively and sequentially closes the switches to connect the make-and-break pick-ups of units A to G to modulate a radio transmitter T with the code signals derived from the record. Initially the stub 221 is positioned to hold the middle contact of the two-way switch 240 apart from its upper and lower contacts. A programming clock 315 energizes the motor M which starts the turntable and the cam 203. The rotation causes the stub to close the middle and upper contacts of the two-way switch, energizing the solenoid 149 and positioning the arm 145 in accordance with wind direction. At the same time cam 203 leaves the recess 211 and raises the follower 209 and the turntable to bring the record into engagement with the pick-up needles. The stub moves on from the two-way switch allowing the middle and lower contacts to close, de-energizing the solenoid and energizing the motor independently of the programming clock. Subsequently the stub cyclically and sequentially closes the remaining switches, which connect the pick-ups in turn to modulate the transmitter to radiate code signals dependent on the indications of the various meteorological instruments to a distant station, where they are received and decoded. When the stub has made one complete revolution, it opens the two-way switch, the turntable is lowered, and the motor stops until restarted by the programming clock. The pick-up heads may be of the crystal or other known type. The apparatus may be stationary, dropped by parachute, or flown on a balloon as a radiosonde, and the connection to the distant station may be by line. Other instrumental combinations may be employed, and if the secrecy of the transmission is compromised, their sequence may be rearranged or a plurality of alternatively coded records may be employed.