Patent GB-718244-A (GB)
Title: Improvements relating to the control of flying objects
IPC: F41G7/24
Filed: 1952-11-11
Abstract: 718,244. Radio-navigation. PATELHOLD PATENTVERWERTUNGS & ELECKTROHOLDING AKT.-GES., and CONTRAVES AKT.-GES. Nov. 11, 1952 [Nov. 15, 1951], No. 28388/52. Class 40 (7) A conical scan beacon more particularly 'for use in a flying object control system is characterized by the radiation of two beams of different widths each rotating about a guide axis in such manner that the angle between the direction of maximum beam intensity and the associated axis is larger for the wider than for the narrower beam. On the flying object the control apparatus is arranged to be influenced by the wider beam and to be transferred to the narrower beam only when the object is within a cone having as axis the narrow beam guide axis and a smaller semiang'e than the angle between the direction of maximum radiation intensity of the narrow beam and its guide axis. In one embodiment, wherein the axes of the beams coincide and the beams rotate with the same angular velocity and phase but are characterized by different carrier or modulation frequencies, signals are received by antennae A1 and A2 feeding receivers D1 and D2 for the wider and narrower beam signals respectively. The separated signals are passed through amplifiers V1 and V2 to the two fixed contacts of changeover relay R at which point one of the signals is selected for application to the utilization circuits A operating the control apparatus S. Relay R is operated according to the strength of the wider beam signals which are fed through non-linear amplifier B and rectifier G to the operating coil of the relay. When the wider beam signals drop below a certain strength the relay R releases and control is transferred from the wider beam signals to the narrower beam signals. To prevent the changeover occurring as suddenly as in this simple embodiment the relay R may be used, not to effect a direct changeover, but to change the bias on a pair of switching valves 'associated one with each circuit. Resistancecapacity charging and discharging circuits are associated with each bias circuit to vary the gain of the switching valves relatively slowly in opposite sense (Fig. 3 not shown) when the relay operates or re'eases. A further modification includes an arrangement to prevent changeover to control by the narrower beam if the rate of change of the wider beam control signa's is high. In this modification the changeover relay circuit is energized through two relays in parallel one of which is fed by the output of the non-linear amplifier B and rectifier G and the other from the output of a rectifying and differentiating circuit also fed from V1 (Fig. 4 not shown). A device may be introduced into the changeover arrangement to prevent any switch over taking place until after a certain time has elapsed. This may either be clockwork driven or electrical ; an electrical arrangement is described with re erence to Fig 5 (not shown). The guides axes of the wider and narrower beams may be independant of each other and the wider beam may, for example, be moved to guide an object originating some distance from the narrow beam axis to that axis for subsequent control by the narrow beam. In this case holding contacts are required in the relay circuit to ensure the changeover to the narrow beam is irreversible.