US 3726494 A
In a missile, means and methods for applying electrical power to the control surface servos after receipt of a firing signal.
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Description (OCR text may contain errors)
Flagg et al. Apr. 10, 1973  MISSILE POWER SFER SYSTEM  Inventors: John M. Flagg; Wendell E. Bard;  References Cited B mar K Christensen; y UNITED STATES PATENTS Edgar an of 2,985,837 5/1961 Ruehleman eta] ..102 70.2 R 2,873,679 2/1959 Gibson ..lO2/70.2 P  Assignee: Hughes Aircraft Company, Culver City, Calif Primary ExaminerBenjamin A. Borchelt Assistant ExaminerThomas H. Webb  Filed: Jan. 18, 1971 Attorney-W. H. MacAllister, Jr. and D. C. Keaveney  Appl. No.: 128,625
 ABSTRACT 52] U S Cl 244/3 14 102/70 2 R In a missile, means and methods for applying electrical 511 Int. Cl. l l) l ;2c 11/ 00 i=42 15/40 13? 3 Surface after receipt a 58 Field of Search ..102/70.2; 200/5;
244/3. 14 1 Claim, 2 Drawing Figures 72' /50 re /4 6 Vaf 71444!!! [aw/4 Ara! 8'54121/05 8 +220 Avr r220 70 zewczzze X 7 rasar as MISSILE POWER TRANSFER SYSTEM DESCRIPTION OF THE PRIOR ART This invention pertains to a means and method for transferring missile power from an external to an internal source.
In the prior art it is usual, upon arming of the missile, to start all of the electrical and electronic equipment, preparatory to firing, including electronic and infrared trackers and the power servos which are used to actuate the control surfaces of the missile.
The turning on of all of the electrical and electronic equipment in the missile generates substantial heat, whereby, if the missile is not fired within a predetermined time, the missile reaches a critical temperature, and it must be disarmed to allow the electrical equipment to be shut off and to allow the missile to cool.
BRIEF DESCRIPTION OF THE INVENTION In the apparatus contemplated by this invention, when the missile is armed, and the power transfer switch is connected to an external source of power, only the tracker and the regulated voltages are turned on. High voltage is not channeled to the servo amplifiers nor to the servos themselves, whereby the amount of heat generated by the electrical system is inconsequential.
When a firing signal is received, the power supply is switched from the external source to an internal source which may be either AC or DC. Typically, the internal source of voltage is a battery which is energized just prior to switching from the external to the internal source of power. When the internal source of power comes up to full voltage full power capability, a power transfer switch transfers the tracker and the regulators from the source of external supply to the internal source of supply, and it also connects the servos and servo amplifiers to the internal source of supply. When It is therefore an object of this invention to control the flow of power to the servos of a missile separately from the flow of power to the remainder of the missile.
It is another object of this invention to energize at least the trackers of a missile when the missile is armed, and to defer the energizing of the high-powered servos and servo amplifiers until after the missile switches to its internal power source.
It is a more particular object of this invention to provide a system and a method for achieving the aboveenumerated objects.
Other objects will become apparent from the following description, taken in connection with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram, partly schematic, of a prior art connection of the external and internal power sources to a missile; and
FIG. 2 is a block diagram, partly schematic, of the missile connected in accordance with this invention.
DETAILED DESCRIPTION Prior Art The prior art is shown in FIG. 1. The electronic power supply 10 is connected through a transfer switch 12 to an external source 14 of alternating power, positioned upon the supporting craft, when the missile is armed. The output of the electronic power supply It) delivers electric power to, for example, an infrared, ultraviolet, or radar target tracker (not shown). The power supply 10 also delivers power to a regulator 16 which is adapted to produce regulated voltages which may be used for bias voltages, and the like, in the electronic systems of the missile. The power supply 10 also delivers electrical power to the servo amplifiers and to the servos. Typically, hydraulic servos may be used which are electrically actuated by power from the power supply 10.
The transfer switch 12 is actuated by a firing signal applied, for example, to the actuating coil 18 which transfers the switch 12 from the external to the internal source of supply 20. The internal source of supply 20 may, for example, be a battery which has a high current capacity and which is enabled by an explosive squib to deliver power, If the power supply 20 is a supply which is constantly available, the coil 18 is typically actuated at the time of firing of the missile. When, however, the battery or supply 20 must be brought up to full power, a time delay may be applied to the firing signal of FIG. 1. For example, the internal power source 20 may be an alkaline battery which is adapted to come up to full power, on the order of 30 amps. in, for example, 200 milliseconds. The firing signal applied to the coil 18, which transfers the transfer switch 12, would then need to be delayed by 200 milliseconds.
DETAILED DESCRIPTION OF THE INVENTION of the rocket engine, the internal source of supply 20 comes up to full power and the transfer switch 12 transfers from external to internal power. When the power supply 20 is instantaneously at its full power, the signal applied to the winding 18, which actuates the transfer switch 12, need not be delayed. Typically, with an alkaline battery for the source 20, it requires approximately 200 milliseconds for the battery 20 to come up to full power after which a delayed firing signal is supplied to the winding 18, transferring the transfer switch from the external supply 14 to the internal supply 20. A voltage dropping resistor 15 may be placed in series with the source 14 to bring the output voltage of the power supply 10 substantially to what it would be in the apparatus of FIG. 1.
While the power supply 10 is connected to the external supply 14, the servos are not energized. When the transfer switch 12 changes from external to internal, the terminals 12A are also connected, therebyapplying a full voltage to the servos and servo amplifiers of the missile.
Thus, in the apparatus of this invention, the servos in the missile are not energized until the missile is fired, at which time power transfers from an external source to an internal source and, simultaneously with the power transfer, power is delivered from the internal source to the missile servos.
By eliminating the energizing of the servos and servo amplifiers in the missile during the period when the missile is armed, the temperature of the missile remains below a critical temperature, whereby the missile may remain armed until it is ready to be fired.
When it is desired to test the servos and/or the tracker, a test voltage of on the order of 220 volts, or whatever other voltage is needed to operate the servos and the tracker, is applied to the test voltage terminal 25, The voltage is also channeled through diode 27 to the tracker and to the regulator 16. The power supply is biased in such a fashion that current does not flow backwards through the power supply.
Thus, the apparatus of this invention performs a process or method of energizing a missile wherein the low powered items are first energized during the arming phase of the missile operation and the highpowered electronic devices, such as servos and servo amplifiers, which generate substantial quantity of heat, are energized after the missile receives a firing signal. In this fashion, the missile never reaches a critical temperature, whereby the missile never needs to be disarmed, cooled, and re-armed prior to firing.
Although the invention has been described in detail above, it is not intended that the invention should be limited by that description, but only by that description in combination with the appended claims.
1. In a missile requiring arming, energizing tracking equipment and control surface circuits of the missile, and firing whereby if the missile is not fired in response to a fire signal within a certain maximum time after energizing the electrical and electronic equipment the missile will reach a critical temperature due to heat generated by the high power requirement of the control surface circuits necessitating the missile be disarmed, wherein the missile includes a first transfer switch for alternately utilizing an external power source prior to firing or an internal power source in response to a fire signal and coupled to a power supply means for supplying regulated voltages and electrical power to a tracker means wherein the improvement comprises:
a second transfer switch coupled between said power supply means and said control surface circuits for maintaining said control surface circuits in an inactivated condition prior to firing whereby said control surface circuits generate no heat and the missile does not reach a critical temperature and for activating said control circuits only when said first and second transfer switches are actuated by a fire signal;
a diode coupled across said second transfer switch for preventing power flow from said power supply to said control surface circuits when said first transfer switch is supplying external power and said second transfer switch is inactivated; and
a test voltage input terminal coupled to said control surface circuits and said tracker means through said diode adapted to accept external power for selectively testing said control surface circuits and said tracking eqpipgnergt.